The low-flow mask oxygen could be a better treatment for emergency psychogenic hyperventilation syndromes: a double-blind, randomized controlled trial

The low-flow mask oxygen could be a better treatment for emergency psychogenic hyperventilation syndromes: a double-blind, randomized controlled trial | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article The low-flow mask oxygen could be a better treatment for emergency psychogenic hyperventilation syndromes: a double-blind, randomized controlled trial Zhenyu Luo, Dongmei Yuan, linhe yang, Yunying Li This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3536139/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objectives To compare the effect of low-flow mask oxygenation (LFMO) with breathing training (BT) for psychogenic hyperventilation syndrome (PHVS), providing more options and evidence for clinical treatment. Methods A double-blind, randomized controlled trial (Registered number: ChiCTR2300072044, June 1, 2023) was conducted in a tertiary hospital from 5 June 2023 to 25 June 2023. Participants were recruited and randomly assigned to the LFMO or BT groups. All participants were guided and presented PHVS, then the LFMO group inhaled 3L/minute oxygen with the oxygen mask, and the BT group took the breath training with 20 breath rate/minute. The length of the recovery from PHVS and the comfort/tolerance score were collected as the primary outcome. and the PH, lactate, K+, Ca2+, PO 2 , and PCo 2 was collected as the secondary outcome. Results Forty-four participants completed the study and were included for analysis (21 for the LFMO group and 23 for the BT group), mainly female (75%, n = 33). After a period of fast breathing, all participants diagnosed with PHVS by the 1st ABG test (Pco 2 : 27.40 ± 3.11; 28.80 ± 1.87) and Nijmegen Questionnaire(23.47 ± 0.66; 23.38 ± 0.58), and all participants recovered from PHVS after interventions. However, the LFMO group showed significant advantages in both the length of recovery (22.41 ± 3.36, p < 0.000) and comfort/tolerance (5.85 ± 1.23, p = 0.011), while no significant difference was detected among secondary outcomes. Conclusion Compared to traditional breath training, low-flow mask oxygenation could be a better treatment for PHVS, especially in emergency departments, with more comfort and faster recovery. hyperventilation low-flow oxygen breath training psychogenic hyperventilation Figures Figure 1 Figure 2 Background Psychogenic hyperventilation is common in emergency departments (ED) worldwide and could be triggered by various reasons, which has been defined as “respiratory rate (> 20 minutes) increased at or before the ED visit, and can not be explained by somatic causes [ 1 ]”, in this way, people breathe in oxygen and exhale carbon dioxide too much in a short period, and some cases could be aggravated into hyperventilation syndrome (PHVS) [ 2 , 3 , 15 ] and finally result in emergency visits [ 1 , 5 , 13 , 14 ]. For its easy-to-use and non-invasive features [ 8 , 10 , 12 ], breath training (BT) has long attracted physicians’ attention and has become the most frequent treatment for psychogenic hyperventilation syndrome (PHVS). However, the PHVS could result in a series of uncomfortable physical feelings, including breath shortness, tingling fingers, chest pain, etc., then provoke psychological symptoms such as anxiety, fear, and even panic disorder [ 5 , 9 , 12 , 13 , 14 , 16 ], it could never be easy for medical staffs to calm and teach patients to slow down their breath rate and adjust their breath mode in ED practice. In addition, a Cochrane evidence-based review has questioned its effectiveness and called for a new safe treatment [ 10 ]. Inspired by the Chinese expert consensus on ED oxygen treatment [ 7 ], which mentioned that oxygen masks with low oxygen flow (< 5L/minute) could lead to carbon dioxide rebreathing. We hypothesize that using oxygen masks with oxygen flow < 5L/minute could be a better treatment for PHVS in the ED setting, both to speed up the patient's physical recovery and to reduce the patient's psychiatric symptoms, as the physiological changes opposite with PHVS, and the using of medical equipment and oxygen supply could psychologically calm the patients with breath shortness rather than ask them to slow down to breathe. Importance There has been a lack of research on psychogenic hyperventilation syndrome in recent years, and existing studies have still focused on studying the effects of BT and have some methodological limitations acknowledged by the authors themselves, such as relying on participants’ self-report symptoms, lack of convincing standards to diagnose the PHVS [ 5 , 8 , 10 , 17 ], besides, as more related factors such as ambient temperature [ 13 ] emerged through new studies, further undermining the credibility of previous studies, a study for new safe treatment is urgent. Objectives of this study This study compares the effect of low-flow mask oxygenation (LFMO) with breathing training (BT) for psychogenic hyperventilation syndrome (PHVS), providing more options and evidence for clinical treatment. MATERIALS AND METHODS Study design and setting A randomized double-blinded controlled experiment was registered in the Chinese Clinical Trial Registry with a definite number ChiCTR2300072044 (the WHO authorities clinical research register platform of China) and approved by the Ethics Committee of Guangyuan central hospital (GYZXLL2023070) and then conducted in there from 5 June 2023 to 25 June 2023, which is the region's largest referral, medical, and teaching center was certificated with the national trauma center, chest pain center, and Stroke center in 2016, 2018, and 2019 separately. It consists of two hospital areas, treating over 20000 emergency visits annually. Participants recruiting The sample size calculation for this study was based on the pilot study with 24 volunteers [ 11 ]. The results showed that the mean duration from diagnosing PHVS to recovery was 27.6 ± 2.3 minutes in the breath training group (BT group) and 21.4 ± 2.5 minutes in the low-flow mask oxygenation group (LFMO group). Assuming α = 0.05 (two-tailed) and 1-β = 90% for this study, 18 study subjects were required in each group, and considering a 10% shedding rate, 20 study subjects had to be recruited in each group, making a total of 40 cases in both groups. Volunteers who signed the informed consent paper, which explains this study detailed, and met the following criteria were recruited. (1) Inclusion criteria: (i) age ≥ 18 years, < 60 years; (ii) voluntary participation in this study;(2) Exclusion criteria: (i) history of significant organic pathology or respiratory disease; (ii)coagulation disorders; (iii) history of psychological disorders (anxiety or panic disorders) [ 6 ]; (iiii) presence of factors that may cause carbon dioxide retention (e.g., BMI ≥ 25, chest trauma) [ 7 ]; (v) communication disorders; (vi) abnormal body temperature (༜36℃ or ≥ 37.3 ℃). Randomization and blinding A simple randomized grouping method was conducted, where the participants drew an enclosed envelope with a unique number, and then the project leader used a computer to divide all numbers equally to LFMO and BT groups randomly. The project leader is responsible for the participants’ recruitment, random grouping, and keeping information. The other researchers who performed the intervention were not informed of their assignment to groups, nor were they informed of the difference between the two interventions; they were not allowed to communicate with the rest of the participants throughout the experiment to avoid disclosure of the grouping. After grouping, the participants were informed of the purpose of the study, the procedures, and the possible symptoms of the study before the start of the experiment but were not informed of their assignment to the experimental group or the control group, nor were they informed of the differences between the two groups; they were asked to remain strictly confidential throughout the experiment and were not allowed to communicate with the rest of the participants to minimize implementation bias. The two groups conducted interventions in separate, enclosed rooms, each with only two participants and two researchers responsible for the intervention simultaneously (Fig. 1 ). Interventions The process was conducted under the ambient temperature of 25℃, and all participants were checked and recorded their body temperatures [ 13 ]. After the grouping, participants were asked to fill out the Anxiety Sensitivity Index (ASI, Consisting of 16 items with a total score ranging from 0 to 64) [ 6 ]. Then they were led to separate rooms and asked to take rapid, deep breaths 40 times/per minute to simulate the PHV and trigger the PHVS, and researchers will check their symptoms with the Nijmegen Questionnaire [ 18 ] (Appendix 1). Once participants meet the criteria for hyperventilation, they would take the first arterial blood gas (ABG) analysis to re-diagnose by biochemical level. Then, the LFMO group inhaled 3L/minute oxygen with the oxygen mask (Fig. 2 ), and the BT group performed the breath training (relaxed, normal breathing with 20 breath rate/minute, taught by researchers after grouping) and started to count the time. Afterward, researchers accompanied the participants and continuously evaluated them with the Nijmegen questionnaire. Once participants met the criteria of recovering from the hyperventilation, researchers stopped the time count and conducted the second ABG for participants; after that, participants were asked to pick a fair number to indicate their feeling of comfort and tolerance of the interventions from one to ten, one means worst, and ten means perfect (Numerical Rating Scale). The research team supervises and guides the intervention process to keep it timely, correct, and safeguard the participants. Data collection and Outcome measurement Sex, age, weight, BMI, ASI, scores of the Nijmegen Questionnaire, and body temperature were collected as the demographic data. The length of the recovery from PHVS and the comfort/tolerance score (participant rating via NRS) were collected as the primary outcome. The secondary outcome was collected as the PH, lactate, K+, Ca2+, PO 2 , and PCo 2 (all collected by ABG tests, performed by the cobas® b 123, ASIA-CORE CO.LTD, Chengdu, the reference range of items are listed in tables). Continuous variables are expressed as mean ± SD, and categorical variables are expressed as frequencies and percentages. Data analysis The independent samples t-test was selected for this study, and Welch’s t-test results were used if the variances were not equal. All tests were performed by the SPSS (version 24.0, IBM Corporation). P-values < 0.05 (two-tailed) were considered statistically significant. Results Participant characteristics Forty-four participants (all Asian) completed the study and were included in the analysis (21 for the LFMO group and 23 for the BT group), mainly female (75%, n = 33). All demographic characteristics between the two groups are within the reasonable range and have no significant difference. Main results Firstly, after a period of fast breathing, all participants diagnosed with PHVS by the 1st ABG test (Pco 2 : 27.40 ± 3.11; 28.80 ± 1.87) and Nijmegen Questionnaire(23.47 ± 0.66; 23.38 ± 0.58) (Table 1 ). Then, all participants recovered from PHVS after interventions. However, the LFMO group showed significant advantages in both the length of recovery (22.41 ± 3.36, p < 0.000) and comfort/tolerance (5.85 ± 1.23, p = 0.011), while no significant difference was detected among secondary outcomes (Table 2 ). Table 1 Results of 1st ABG test Items BT Group LFMO Group Reference range P-value Participants 23 21 Gender 0.400 male 5 6 Female 18 15 Age(year) 23.65 ± 3.37 23.66 ± 2.55 0.987 Weight(Kg) 56.69 ± 8.13 57.85 ± 7.11 0.618 BMI 21.00 ± 1.57 21.33 ± 0.99 0.417 ASI 18.39 ± 1.75 17.90 ± 1.54 0.336 Scores of Nijmegen Questionnaire 23.47 ± 0.66 23.38 ± 0.58 0.612 Body temperature 36.41 ± 0.15 36.42 ± 0.13 0.886 Ph 7.46 ± 0.02 7.46 ± 0.01 7.350–7.450 0.445 Pco 2 27.40 ± 3.11 28.80 ± 1.87 32.0–48.0 0.076 Po 2 104.53 ± 8.39 104.83 ± 5.89 83.0-108.0 0.891 Oxygen index(OI) 479.72 ± 53.15 495.75 ± 29.20 0.218 So 2 99.01 ± 0.91 98.00 ± 0.79 94.0–98.0 0.961 Anion gap(AG) 12.37 ± 1.62 13.05 ± 1.32 10.0–14.0 0.138* Base excess(BE) -2.14 ± 0.72 -2.01 ± 1.03 -3.0-3.0 0.645 Methemoglobin(MetHb)(%) 0.45 ± 0.21 0.45 ± 0.17 0.0-1.5 0.946 reduced hemoglobin(HHB)(%) 0.60 ± 0.48 0.45 ± 0.29 0.0-2.9 0.225 lactate 1.72 ± 0.23 1.68 ± 0.16 1.0-1.8 0.513 glucose 5.33 ± 0.73 5.10 ± 0.46 4.1–5.6 0.228 oxyhemoglobin (O 2 Hb)(%) 96.90 ± 0.93 97.62 ± 0.73 94.0–98.0 0.007* Carboxyhemoglobin(COHb) 2.23 ± 0.33 2.16 ± 0.29 0.0–3.0 0.442 cHCO3- 19.41 ± 1.43 19.71 ± 1.77 21.0–28.0 0.538 Buffer bases(BB) 43.49 ± 2.16 43.26 ± 2.23 45.0–55.0 0.727 Extracellular BE(BEecf) -3.62 ± 0.55 -3.52 ± 0.79 -2.0-3.0 0.636 Base excess actual(Beact) -1.43 ± 0.69 -1.69 ± 0.63 -2.0-3.0 0.209 cH+ 33.80 ± 3.54 35.83 ± 3.36 36.0–44.0 0.059* K+ 3.56 ± 0.18 3.54 ± 0.14 3.50–5.10 0.661 Na+ 136.66 ± 3.67 136.40 ± 3.56 136.0-145.0 0.819 CL- 105.69 ± 5.02 104.06 ± 3.16 98.0-107.0 0.211 Ca2+ 1.04 ± 0.08 1.03 ± 0.057 1.150–1.330 0.727 Total haemoglobin(tHb) 12.60 ± 1.69 13.15 ± 1.00 11.5–17.8 0.201 Hematocrit(Hct)(%) 40.39 ± 4.46 40.35 ± 3.39 36.0–53.0 0.974 Alveolar-arterial oxygen gradient(AaDO2) 8.02 ± 1.70 9.07 ± 1.46 5.0–20.0 0.034* *: p < 0.05 Table 2 Results of 2st ABG test Items BT Group LFMO Group Reference range P-value Participants 23 21 Gender 0.400 male 5 6 Female 18 15 Age 23.82 ± 3.39 23.80 ± 3.44 0.987 Weight 57.00 ± 7.96 57.66 ± 7.62 0.778 BMI 21.10 ± 1.49 21.36 ± 1.26 0.541 ASI 18.39 ± 1.75 17.85 ± 1.55 0.293 Scores of Nijmegen Questionnaire 19.91 ± 1.08 19.8 ± 1.03 0.748 Body temperature 36.41 ± 0.15 36.42 ± 0.13 0.886 Ph 7.43 ± 0.01 7.44 ± 0.003 7.350–7.450 0.167 Pco 2 33.25 ± 1.34 33.63 ± 1.56 32.0–48.0 0.390 Po 2 103.07 ± 8.09 103.01 ± 5.27 83.0-108.0 0.977 Oxygen index(OI) 493.31 ± 40.70 494.75 ± 27.16 0.892 So 2 98.50 ± 0.94 98.80 ± 0.80 94.0–98.0 0.264 Anion gap(AG) 12.50 ± 1.49 13.00 ± 1.23 10.0–14.0 0.240 Base excess(BE) -1.99 ± 0.91 -2.00 ± 1.02 -3.0-3.0 0.975 Methemoglobin(MetHb)(%) 0.43 ± 0.21 0.44 ± 0.16 0.0-1.5 0.884 reduced hemoglobin(HHB)(%) 0.53 ± 0.48 0.44 ± 0.27 0.0-2.9 0.482 lactate 1.80 ± 0.31 1.68 ± 0.17 1.0-1.8 0.111 glucose 5.26 ± 0.68 5.10 ± 0.45 4.1–5.6 0.357 oxyhemoglobin (O 2 Hb)(%) 97.22 ± 1.13 97.67 ± 0.71 94.0–98.0 0.131 Carboxyhemoglobin(COHb) 2.27 ± 0.31 2.14 ± 0.27 0.0–3.0 0.154 cHCO3- 19.77 ± 1.57 19.60 ± 1.68 21.0–28.0 0.726 Buffer bases(BB) 43.68 ± 2.03 43.22 ± 2.28 45.0–55.0 0.481 Extracellular BE(BEecf) -3.61 ± 0.58 -3.51 ± 0.78 -2.0-3.0 0.632 Base excess actual(Beact) -1.42 ± 0.69 -1.68 ± 0.63 -2.0-3.0 0.207 cH+ 34.42 ± 3.59 35.81 ± 3.35 36.0–44.0 0.192 K+ 3.58 ± 0.16 3.55 ± 0.14 3.50–5.10 0.471 Na+ 136.41 ± 3.50 136.74 ± 1.33 136.0-145.0 0.687 CL- 105.34 ± 4.66 103.92 ± 3.16 98.0-107.0 0.248 Ca2+ 1.10 ± 0.06 1.09 ± 0.05 1.150–1.330 0.528 Total haemoglobin(tHb) 12.90 ± 1.90 13.15 ± 1.00 11.5–17.8 0.591 Hematocrit(Hct)(%) 42.43 ± 3.46 40.40 ± 3.33 36.0–53.0 0.055 Alveolar-arterial oxygen gradient(AaDO2) 8.68 ± 0.82 9.15.97 ± 1.36 5.0–20.0 0.174 Comfort/tolerance 4.86 ± 1.21 5.85 ± 1.23 0.011* Length of recovery 27.40 ± 2.27 22.41 ± 3.36 0.000* *: p < 0.05 Discussion BT therapy has become a popularized treatment or healthcare exercise for types of HVS, including PHVS, although a Cochrane review doubted its usefulness and effectiveness [ 8 , 10 , 12 ]. To our knowledge, this study is the first to apply LFMO to treating PHVS, and it provides evidence for LFMO as a new treatment for PHVS in the clinical setting. Compared to the BT group, the LFMO group showed a remarkable recovery speed of 22.41 ± 3.36 minutes, while the BT group needed 27.40 ± 2.27 minutes. As a type of ventilation with unclear etiology[ 1 , 2 , 10 ], studies have shown that PHVS is more likely present in people with panic or anxiety history as well as higher ASI scores [ 6 , 5 , 12 , 13 ], which could make BT more complex to perform in the actual clinical situation. Besides, to eliminate potential bias and focus on investigating the effectiveness of two treatments, the researchers taught the participants of the BT group how to perform breath training before the intervention. If this period had been considered, the difference in recovery time between the two groups would be more significant, and further study needs to be done among participants with panic or anxiety disorder to contribute more evidence for LFMO in the clinical setting. Another significant advantage of the LFMO group is the comfort/tolerance score (5.85 ± 1.23) higher than the BT group (4.86 ± 1.21), although each group has a participant withdraw from intervention with intolerance of PHVS. Considering the fear, paralysis, dizziness, and breathlessness caused by PHVS [ 1 , 2 , 12 , 14 , 18 ], LFMO uses a simple device to perform the treatment with stable effects, and the low-flow oxygen in the mask during the treatment may also comfort patients and soothe their psychological burden [ 4 ]. In contrast, BT relies more on patient subjective cooperation and requires patients to actively control their breathing rate despite their fear, which may account for the difference in this score. Although the ABG test detected no significant difference in secondary outcomes in this study, as lactate and ion change correlate with PHVS duration [ 1 ], considering the LFMO has a shorter recovery time, and the BT may need more time in the clinical setting, we hypothesize that LFMO may have an advantage in keeping stable lactate and ion level which would be tested in future. Additionally, this study also detected the increased lactate level and Potassium decrease during PHVS, which aligns with Avest et al. (2011), but we also found a calcium level change, which has not been mentioned by Avest et al. (2011), which is recommended for more investigation. Limitation Firstly, PHVS is a disease closely related to subjective feelings. Informing patients of the symptoms of PHVS due to ethical requirements may reduce their fears and impact the experiment results [ 12 ]. Secondly, while the sample size met the requirements of the experiment, a larger sample size would undoubtedly increase the validity of this study. Conclusion Compared to traditional breath training, low-flow mask oxygenation could be a better treatment for PHVS, especially in emergency ddepatments, with more comfort and faster recovery. Abbreviations ED Emergency department BT Breath training LFMO Low-flow mask oxygenation PHVS Psychogenic hyperventilation syndrome ASI Anxiety Sensitivity Index ABG Arterial blood gas Declarations Availability of data and materials The datasets generated and analyzed in this study are not publicly available due protect patient privacy but are available from the corresponding author on reasonable request. Consent for publication Not applicable Funding None Ethics approval and consent to participate The study followed the Sex and Gender Equity in Research (SAGER) guidelines and is in line with the Declaration of Helsinki, Participants can freely withdraw from the study without any effect, which is registered in the Chinese Clinical Trial Registry with a definite number ChiCTR2300072044 and approved by the Ethics Committee of Guangyuan Central Hospital (GYZXLL2023070). All participants voluntarily signed the informed consent. All data from this study are confidential and supervised by the Ethics Committee of Guangyuan Central Hospital. Authors’ contributions ZYL and DMY: conception, design, the analytical plan, manuscript drafting, and contributed equally to this work. LHY and YYL: data acquisition and data analysis. Conflict of interest statement The authors declare that they have no competing interests. Acknowledgment: None References Avest E, Patist FM, Maaten JC, et al. 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PLoS ONE. 2022;17:e0265607. Williams CYK, Williams RWK, Knight R, et al. Hyperventilation Syndrome: Investigating the Relationship Between Nijmegen Questionnaire, Vestibular Function Tests, and Patient Symptoms. Otology & Neurotology: Official Publication of the American Otological Society . Am Neurotology Soc [and] Eur Acad Otology Neurotology. 2020;41:e349–56. Additional Declarations No competing interests reported. Supplementary Files appendix1.pdf Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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yang","email":"","orcid":"","institution":"guangyuan central hospital","correspondingAuthor":false,"prefix":"","firstName":"linhe","middleName":"","lastName":"yang","suffix":""},{"id":287979438,"identity":"98bcdcc1-388f-4066-9663-3753832002c7","order_by":3,"name":"Yunying Li","email":"","orcid":"","institution":"guangyuan central hospital","correspondingAuthor":false,"prefix":"","firstName":"Yunying","middleName":"","lastName":"Li","suffix":""}],"badges":[],"createdAt":"2023-11-01 14:44:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3536139/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3536139/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":54864911,"identity":"190330f1-6b2e-48c4-866d-79b0cf615782","added_by":"auto","created_at":"2024-04-17 20:41:31","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":55890,"visible":true,"origin":"","legend":"\u003cp\u003eThe CONSORT flowchart.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-3536139/v1/8437416da5b1ba6808fed433.png"},{"id":54864914,"identity":"0ff3b5df-fb66-4f81-a3ea-e5ab4f185b53","added_by":"auto","created_at":"2024-04-17 20:41:31","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":359793,"visible":true,"origin":"","legend":"\u003cp\u003eThe oxygen mask.\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-3536139/v1/979d3980afd8661900c9d02f.jpeg"},{"id":58021769,"identity":"1e4c8c1f-91e8-4069-899c-1d14ce31b6b7","added_by":"auto","created_at":"2024-06-10 05:19:14","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1030916,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3536139/v1/8bbc3d45-de0d-4a5c-8ce3-0bf249d4df9c.pdf"},{"id":54864912,"identity":"a6a56a47-8714-4552-bd44-cba72181b93f","added_by":"auto","created_at":"2024-04-17 20:41:31","extension":"pdf","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":83943,"visible":true,"origin":"","legend":"","description":"","filename":"appendix1.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3536139/v1/2b662ebac815f873d5a5cba6.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The low-flow mask oxygen could be a better treatment for emergency psychogenic hyperventilation syndromes: a double-blind, randomized controlled trial","fulltext":[{"header":"Background","content":"\u003cp\u003ePsychogenic hyperventilation is common in emergency departments (ED) worldwide and could be triggered by various reasons, which has been defined as \u0026ldquo;respiratory rate (\u0026gt;\u0026thinsp;20 minutes) increased at or before the ED visit, and can not be explained by somatic causes [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u0026rdquo;, in this way, people breathe in oxygen and exhale carbon dioxide too much in a short period, and some cases could be aggravated into hyperventilation syndrome (PHVS) [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] and finally result in emergency visits [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFor its easy-to-use and non-invasive features [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], breath training (BT) has long attracted physicians\u0026rsquo; attention and has become the most frequent treatment for psychogenic hyperventilation syndrome (PHVS). However, the PHVS could result in a series of uncomfortable physical feelings, including breath shortness, tingling fingers, chest pain, etc., then provoke psychological symptoms such as anxiety, fear, and even panic disorder [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e], it could never be easy for medical staffs to calm and teach patients to slow down their breath rate and adjust their breath mode in ED practice. In addition, a Cochrane evidence-based review has questioned its effectiveness and called for a new safe treatment [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eInspired by the Chinese expert consensus on ED oxygen treatment [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], which mentioned that oxygen masks with low oxygen flow (\u0026lt;\u0026thinsp;5L/minute) could lead to carbon dioxide rebreathing. We hypothesize that using oxygen masks with oxygen flow\u0026thinsp;\u0026lt;\u0026thinsp;5L/minute could be a better treatment for PHVS in the ED setting, both to speed up the patient's physical recovery and to reduce the patient's psychiatric symptoms, as the physiological changes opposite with PHVS, and the using of medical equipment and oxygen supply could psychologically calm the patients with breath shortness rather than ask them to slow down to breathe.\u003c/p\u003e \u003cdiv id=\"Sec2\" class=\"Section2\"\u003e \u003ch2\u003eImportance\u003c/h2\u003e \u003cp\u003eThere has been a lack of research on psychogenic hyperventilation syndrome in recent years, and existing studies have still focused on studying the effects of BT and have some methodological limitations acknowledged by the authors themselves, such as relying on participants\u0026rsquo; self-report symptoms, lack of convincing standards to diagnose the PHVS [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], besides, as more related factors such as ambient temperature [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] emerged through new studies, further undermining the credibility of previous studies, a study for new safe treatment is urgent.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eObjectives of this study\u003c/h2\u003e \u003cp\u003eThis study compares the effect of low-flow mask oxygenation (LFMO) with breathing training (BT) for psychogenic hyperventilation syndrome (PHVS), providing more options and evidence for clinical treatment.\u003c/p\u003e \u003c/div\u003e"},{"header":"MATERIALS AND METHODS","content":"\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStudy design and setting\u003c/h2\u003e \u003cp\u003e A randomized double-blinded controlled experiment was registered in the Chinese Clinical Trial Registry with a definite number ChiCTR2300072044 (the WHO authorities clinical research register platform of China) and approved by the Ethics Committee of Guangyuan central hospital (GYZXLL2023070) and then conducted in there from 5 June 2023 to 25 June 2023, which is the region's largest referral, medical, and teaching center was certificated with the national trauma center, chest pain center, and Stroke center in 2016, 2018, and 2019 separately. It consists of two hospital areas, treating over 20000 emergency visits annually.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eParticipants recruiting\u003c/h2\u003e \u003cp\u003eThe sample size calculation for this study was based on the pilot study with 24 volunteers [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. The results showed that the mean duration from diagnosing PHVS to recovery was 27.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3 minutes in the breath training group (BT group) and 21.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.5 minutes in the low-flow mask oxygenation group (LFMO group). Assuming α\u0026thinsp;=\u0026thinsp;0.05 (two-tailed) and 1-β\u0026thinsp;=\u0026thinsp;90% for this study, 18 study subjects were required in each group, and considering a 10% shedding rate, 20 study subjects had to be recruited in each group, making a total of 40 cases in both groups.\u003c/p\u003e \u003cp\u003eVolunteers who signed the informed consent paper, which explains this study detailed, and met the following criteria were recruited. (1) Inclusion criteria: (i) age\u0026thinsp;\u0026ge;\u0026thinsp;18 years, \u0026lt;\u0026thinsp;60 years; (ii) voluntary participation in this study;(2) Exclusion criteria: (i) history of significant organic pathology or respiratory disease; (ii)coagulation disorders; (iii) history of psychological disorders (anxiety or panic disorders) [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]; (iiii) presence of factors that may cause carbon dioxide retention (e.g., BMI\u0026thinsp;\u0026ge;\u0026thinsp;25, chest trauma) [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]; (v) communication disorders; (vi) abnormal body temperature (༜36℃ or \u0026ge;\u0026thinsp;37.3 ℃).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eRandomization and blinding\u003c/h2\u003e \u003cp\u003eA simple randomized grouping method was conducted, where the participants drew an enclosed envelope with a unique number, and then the project leader used a computer to divide all numbers equally to LFMO and BT groups randomly.\u003c/p\u003e \u003cp\u003eThe project leader is responsible for the participants\u0026rsquo; recruitment, random grouping, and keeping information. The other researchers who performed the intervention were not informed of their assignment to groups, nor were they informed of the difference between the two interventions; they were not allowed to communicate with the rest of the participants throughout the experiment to avoid disclosure of the grouping. After grouping, the participants were informed of the purpose of the study, the procedures, and the possible symptoms of the study before the start of the experiment but were not informed of their assignment to the experimental group or the control group, nor were they informed of the differences between the two groups; they were asked to remain strictly confidential throughout the experiment and were not allowed to communicate with the rest of the participants to minimize implementation bias. The two groups conducted interventions in separate, enclosed rooms, each with only two participants and two researchers responsible for the intervention simultaneously (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eInterventions\u003c/h2\u003e \u003cp\u003eThe process was conducted under the ambient temperature of 25℃, and all participants were checked and recorded their body temperatures [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. After the grouping, participants were asked to fill out the Anxiety Sensitivity Index (ASI, Consisting of 16 items with a total score ranging from 0 to 64) [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Then they were led to separate rooms and asked to take rapid, deep breaths 40 times/per minute to simulate the PHV and trigger the PHVS, and researchers will check their symptoms with the Nijmegen Questionnaire [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e] (Appendix 1). Once participants meet the criteria for hyperventilation, they would take the first arterial blood gas (ABG) analysis to re-diagnose by biochemical level. Then, the LFMO group inhaled 3L/minute oxygen with the oxygen mask (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e), and the BT group performed the breath training (relaxed, normal breathing with 20 breath rate/minute, taught by researchers after grouping) and started to count the time. Afterward, researchers accompanied the participants and continuously evaluated them with the Nijmegen questionnaire. Once participants met the criteria of recovering from the hyperventilation, researchers stopped the time count and conducted the second ABG for participants; after that, participants were asked to pick a fair number to indicate their feeling of comfort and tolerance of the interventions from one to ten, one means worst, and ten means perfect (Numerical Rating Scale). The research team supervises and guides the intervention process to keep it timely, correct, and safeguard the participants.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eData collection and Outcome measurement\u003c/h2\u003e \u003cp\u003eSex, age, weight, BMI, ASI, scores of the Nijmegen Questionnaire, and body temperature were collected as the demographic data. The length of the recovery from PHVS and the comfort/tolerance score (participant rating via NRS) were collected as the primary outcome. The secondary outcome was collected as the PH, lactate, K+, Ca2+, PO\u003csub\u003e2\u003c/sub\u003e, and PCo\u003csub\u003e2\u003c/sub\u003e (all collected by ABG tests, performed by the cobas\u0026reg; b 123, ASIA-CORE CO.LTD, Chengdu, the reference range of items are listed in tables). Continuous variables are expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD, and categorical variables are expressed as frequencies and percentages.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eData analysis\u003c/h2\u003e \u003cp\u003eThe independent samples t-test was selected for this study, and Welch\u0026rsquo;s t-test results were used if the variances were not equal. All tests were performed by the SPSS (version 24.0, IBM Corporation). P-values\u0026thinsp;\u0026lt;\u0026thinsp;0.05 (two-tailed) were considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eParticipant characteristics\u003c/p\u003e \u003cp\u003eForty-four participants (all Asian) completed the study and were included in the analysis (21 for the LFMO group and 23 for the BT group), mainly female (75%, n\u0026thinsp;=\u0026thinsp;33). All demographic characteristics between the two groups are within the reasonable range and have no significant difference.\u003c/p\u003e \u003cp\u003eMain results\u003c/p\u003e \u003cp\u003eFirstly, after a period of fast breathing, all participants diagnosed with PHVS by the 1st ABG test (Pco\u003csub\u003e2\u003c/sub\u003e: 27.40\u0026thinsp;\u0026plusmn;\u0026thinsp;3.11; 28.80\u0026thinsp;\u0026plusmn;\u0026thinsp;1.87) and Nijmegen Questionnaire(23.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.66; 23.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.58) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Then, all participants recovered from PHVS after interventions. However, the LFMO group showed significant advantages in both the length of recovery (22.41\u0026thinsp;\u0026plusmn;\u0026thinsp;3.36, p\u0026thinsp;\u0026lt;\u0026thinsp;0.000) and comfort/tolerance (5.85\u0026thinsp;\u0026plusmn;\u0026thinsp;1.23, p\u0026thinsp;=\u0026thinsp;0.011), while no significant difference was detected among secondary outcomes (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResults of 1st ABG test\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eItems\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBT Group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eLFMO Group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eReference range\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eP-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParticipants\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.400\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003emale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge(year)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23.65\u0026thinsp;\u0026plusmn;\u0026thinsp;3.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.66\u0026thinsp;\u0026plusmn;\u0026thinsp;2.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.987\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWeight(Kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e56.69\u0026thinsp;\u0026plusmn;\u0026thinsp;8.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e57.85\u0026thinsp;\u0026plusmn;\u0026thinsp;7.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.618\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21.00\u0026thinsp;\u0026plusmn;\u0026thinsp;1.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21.33\u0026thinsp;\u0026plusmn;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.417\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eASI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18.39\u0026thinsp;\u0026plusmn;\u0026thinsp;1.75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17.90\u0026thinsp;\u0026plusmn;\u0026thinsp;1.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.336\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eScores of Nijmegen Questionnaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.612\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBody temperature\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e36.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e36.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.886\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePh\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.46\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.46\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e7.350\u0026ndash;7.450\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.445\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePco\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e27.40\u0026thinsp;\u0026plusmn;\u0026thinsp;3.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28.80\u0026thinsp;\u0026plusmn;\u0026thinsp;1.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e32.0\u0026ndash;48.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.076\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePo\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e104.53\u0026thinsp;\u0026plusmn;\u0026thinsp;8.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e104.83\u0026thinsp;\u0026plusmn;\u0026thinsp;5.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e83.0-108.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.891\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOxygen index(OI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e479.72\u0026thinsp;\u0026plusmn;\u0026thinsp;53.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e495.75\u0026thinsp;\u0026plusmn;\u0026thinsp;29.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.218\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSo\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e99.01\u0026thinsp;\u0026plusmn;\u0026thinsp;0.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e98.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e94.0\u0026ndash;98.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.961\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAnion gap(AG)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12.37\u0026thinsp;\u0026plusmn;\u0026thinsp;1.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.05\u0026thinsp;\u0026plusmn;\u0026thinsp;1.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10.0\u0026ndash;14.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.138*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBase excess(BE)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-2.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-2.01\u0026thinsp;\u0026plusmn;\u0026thinsp;1.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-3.0-3.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.645\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMethemoglobin(MetHb)(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.0-1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.946\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ereduced hemoglobin(HHB)(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.60\u0026thinsp;\u0026plusmn;\u0026thinsp;0.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.0-2.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.225\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003elactate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.72\u0026thinsp;\u0026plusmn;\u0026thinsp;0.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.0-1.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.513\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eglucose\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5.33\u0026thinsp;\u0026plusmn;\u0026thinsp;0.73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.1\u0026ndash;5.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.228\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eoxyhemoglobin (O\u003csub\u003e2\u003c/sub\u003eHb)(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e96.90\u0026thinsp;\u0026plusmn;\u0026thinsp;0.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e97.62\u0026thinsp;\u0026plusmn;\u0026thinsp;0.73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e94.0\u0026ndash;98.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.007*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCarboxyhemoglobin(COHb)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.23\u0026thinsp;\u0026plusmn;\u0026thinsp;0.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.16\u0026thinsp;\u0026plusmn;\u0026thinsp;0.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.0\u0026ndash;3.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.442\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ecHCO3-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19.41\u0026thinsp;\u0026plusmn;\u0026thinsp;1.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19.71\u0026thinsp;\u0026plusmn;\u0026thinsp;1.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e21.0\u0026ndash;28.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.538\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBuffer bases(BB)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e43.49\u0026thinsp;\u0026plusmn;\u0026thinsp;2.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e43.26\u0026thinsp;\u0026plusmn;\u0026thinsp;2.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e45.0\u0026ndash;55.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.727\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eExtracellular BE(BEecf)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-3.62\u0026thinsp;\u0026plusmn;\u0026thinsp;0.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-3.52\u0026thinsp;\u0026plusmn;\u0026thinsp;0.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-2.0-3.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.636\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBase excess actual(Beact)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-1.43\u0026thinsp;\u0026plusmn;\u0026thinsp;0.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-1.69\u0026thinsp;\u0026plusmn;\u0026thinsp;0.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-2.0-3.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.209\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ecH+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33.80\u0026thinsp;\u0026plusmn;\u0026thinsp;3.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e35.83\u0026thinsp;\u0026plusmn;\u0026thinsp;3.36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e36.0\u0026ndash;44.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.059*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eK+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.56\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.50\u0026ndash;5.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.661\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNa+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e136.66\u0026thinsp;\u0026plusmn;\u0026thinsp;3.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e136.40\u0026thinsp;\u0026plusmn;\u0026thinsp;3.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e136.0-145.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.819\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCL-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e105.69\u0026thinsp;\u0026plusmn;\u0026thinsp;5.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e104.06\u0026thinsp;\u0026plusmn;\u0026thinsp;3.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e98.0-107.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.211\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCa2+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.04\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.057\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.150\u0026ndash;1.330\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.727\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal haemoglobin(tHb)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12.60\u0026thinsp;\u0026plusmn;\u0026thinsp;1.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.15\u0026thinsp;\u0026plusmn;\u0026thinsp;1.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e11.5\u0026ndash;17.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.201\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHematocrit(Hct)(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e40.39\u0026thinsp;\u0026plusmn;\u0026thinsp;4.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40.35\u0026thinsp;\u0026plusmn;\u0026thinsp;3.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e36.0\u0026ndash;53.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.974\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAlveolar-arterial oxygen gradient(AaDO2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8.02\u0026thinsp;\u0026plusmn;\u0026thinsp;1.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.07\u0026thinsp;\u0026plusmn;\u0026thinsp;1.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.0\u0026ndash;20.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.034*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e*: p\u0026thinsp;\u0026lt;\u0026thinsp;0.05\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResults of 2st ABG test\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eItems\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBT Group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eLFMO Group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eReference range\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eP-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParticipants\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.400\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003emale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23.82\u0026thinsp;\u0026plusmn;\u0026thinsp;3.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.80\u0026thinsp;\u0026plusmn;\u0026thinsp;3.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.987\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWeight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e57.00\u0026thinsp;\u0026plusmn;\u0026thinsp;7.96\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e57.66\u0026thinsp;\u0026plusmn;\u0026thinsp;7.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.778\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21.10\u0026thinsp;\u0026plusmn;\u0026thinsp;1.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21.36\u0026thinsp;\u0026plusmn;\u0026thinsp;1.26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.541\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eASI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18.39\u0026thinsp;\u0026plusmn;\u0026thinsp;1.75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17.85\u0026thinsp;\u0026plusmn;\u0026thinsp;1.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.293\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eScores of Nijmegen Questionnaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19.91\u0026thinsp;\u0026plusmn;\u0026thinsp;1.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.748\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBody temperature\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e36.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e36.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.886\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePh\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.43\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.003\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e7.350\u0026ndash;7.450\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.167\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePco\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33.25\u0026thinsp;\u0026plusmn;\u0026thinsp;1.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e33.63\u0026thinsp;\u0026plusmn;\u0026thinsp;1.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e32.0\u0026ndash;48.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.390\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePo\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e103.07\u0026thinsp;\u0026plusmn;\u0026thinsp;8.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e103.01\u0026thinsp;\u0026plusmn;\u0026thinsp;5.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e83.0-108.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.977\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOxygen index(OI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e493.31\u0026thinsp;\u0026plusmn;\u0026thinsp;40.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e494.75\u0026thinsp;\u0026plusmn;\u0026thinsp;27.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.892\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSo\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e98.50\u0026thinsp;\u0026plusmn;\u0026thinsp;0.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e98.80\u0026thinsp;\u0026plusmn;\u0026thinsp;0.80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e94.0\u0026ndash;98.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.264\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAnion gap(AG)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12.50\u0026thinsp;\u0026plusmn;\u0026thinsp;1.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.00\u0026thinsp;\u0026plusmn;\u0026thinsp;1.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10.0\u0026ndash;14.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.240\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBase excess(BE)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-1.99\u0026thinsp;\u0026plusmn;\u0026thinsp;0.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-2.00\u0026thinsp;\u0026plusmn;\u0026thinsp;1.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-3.0-3.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.975\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMethemoglobin(MetHb)(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.43\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.0-1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.884\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ereduced hemoglobin(HHB)(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.0-2.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.482\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003elactate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.80\u0026thinsp;\u0026plusmn;\u0026thinsp;0.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.0-1.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.111\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eglucose\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.1\u0026ndash;5.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.357\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eoxyhemoglobin (O\u003csub\u003e2\u003c/sub\u003eHb)(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e97.22\u0026thinsp;\u0026plusmn;\u0026thinsp;1.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e97.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e94.0\u0026ndash;98.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.131\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCarboxyhemoglobin(COHb)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.0\u0026ndash;3.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.154\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ecHCO3-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19.77\u0026thinsp;\u0026plusmn;\u0026thinsp;1.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19.60\u0026thinsp;\u0026plusmn;\u0026thinsp;1.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e21.0\u0026ndash;28.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.726\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBuffer bases(BB)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e43.68\u0026thinsp;\u0026plusmn;\u0026thinsp;2.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e43.22\u0026thinsp;\u0026plusmn;\u0026thinsp;2.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e45.0\u0026ndash;55.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.481\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eExtracellular BE(BEecf)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-3.61\u0026thinsp;\u0026plusmn;\u0026thinsp;0.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-3.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-2.0-3.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.632\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBase excess actual(Beact)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-1.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-1.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-2.0-3.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.207\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ecH+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e34.42\u0026thinsp;\u0026plusmn;\u0026thinsp;3.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e35.81\u0026thinsp;\u0026plusmn;\u0026thinsp;3.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e36.0\u0026ndash;44.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.192\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eK+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.58\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.55\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.50\u0026ndash;5.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.471\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNa+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e136.41\u0026thinsp;\u0026plusmn;\u0026thinsp;3.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e136.74\u0026thinsp;\u0026plusmn;\u0026thinsp;1.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e136.0-145.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.687\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCL-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e105.34\u0026thinsp;\u0026plusmn;\u0026thinsp;4.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e103.92\u0026thinsp;\u0026plusmn;\u0026thinsp;3.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e98.0-107.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.248\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCa2+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.09\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.150\u0026ndash;1.330\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.528\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal haemoglobin(tHb)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12.90\u0026thinsp;\u0026plusmn;\u0026thinsp;1.90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.15\u0026thinsp;\u0026plusmn;\u0026thinsp;1.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e11.5\u0026ndash;17.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.591\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHematocrit(Hct)(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e42.43\u0026thinsp;\u0026plusmn;\u0026thinsp;3.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40.40\u0026thinsp;\u0026plusmn;\u0026thinsp;3.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e36.0\u0026ndash;53.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.055\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAlveolar-arterial oxygen gradient(AaDO2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.15.97\u0026thinsp;\u0026plusmn;\u0026thinsp;1.36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.0\u0026ndash;20.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.174\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eComfort/tolerance\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.86\u0026thinsp;\u0026plusmn;\u0026thinsp;1.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5.85\u0026thinsp;\u0026plusmn;\u0026thinsp;1.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.011*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLength of recovery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e27.40\u0026thinsp;\u0026plusmn;\u0026thinsp;2.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22.41\u0026thinsp;\u0026plusmn;\u0026thinsp;3.36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.000*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e*: p\u0026thinsp;\u0026lt;\u0026thinsp;0.05\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eBT therapy has become a popularized treatment or healthcare exercise for types of HVS, including PHVS, although a Cochrane review doubted its usefulness and effectiveness [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. To our knowledge, this study is the first to apply LFMO to treating PHVS, and it provides evidence for LFMO as a new treatment for PHVS in the clinical setting.\u003c/p\u003e \u003cp\u003eCompared to the BT group, the LFMO group showed a remarkable recovery speed of 22.41\u0026thinsp;\u0026plusmn;\u0026thinsp;3.36 minutes, while the BT group needed 27.40\u0026thinsp;\u0026plusmn;\u0026thinsp;2.27 minutes. As a type of ventilation with unclear etiology[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], studies have shown that PHVS is more likely present in people with panic or anxiety history as well as higher ASI scores [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], which could make BT more complex to perform in the actual clinical situation. Besides, to eliminate potential bias and focus on investigating the effectiveness of two treatments, the researchers taught the participants of the BT group how to perform breath training before the intervention. If this period had been considered, the difference in recovery time between the two groups would be more significant, and further study needs to be done among participants with panic or anxiety disorder to contribute more evidence for LFMO in the clinical setting.\u003c/p\u003e \u003cp\u003eAnother significant advantage of the LFMO group is the comfort/tolerance score (5.85\u0026thinsp;\u0026plusmn;\u0026thinsp;1.23) higher than the BT group (4.86\u0026thinsp;\u0026plusmn;\u0026thinsp;1.21), although each group has a participant withdraw from intervention with intolerance of PHVS. Considering the fear, paralysis, dizziness, and breathlessness caused by PHVS [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e], LFMO uses a simple device to perform the treatment with stable effects, and the low-flow oxygen in the mask during the treatment may also comfort patients and soothe their psychological burden [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. In contrast, BT relies more on patient subjective cooperation and requires patients to actively control their breathing rate despite their fear, which may account for the difference in this score.\u003c/p\u003e \u003cp\u003eAlthough the ABG test detected no significant difference in secondary outcomes in this study, as lactate and ion change correlate with PHVS duration [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e], considering the LFMO has a shorter recovery time, and the BT may need more time in the clinical setting, we hypothesize that LFMO may have an advantage in keeping stable lactate and ion level which would be tested in future. Additionally, this study also detected the increased lactate level and Potassium decrease during PHVS, which aligns with Avest et al. (2011), but we also found a calcium level change, which has not been mentioned by Avest et al. (2011), which is recommended for more investigation.\u003c/p\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eLimitation\u003c/h2\u003e \u003cp\u003eFirstly, PHVS is a disease closely related to subjective feelings. Informing patients of the symptoms of PHVS due to ethical requirements may reduce their fears and impact the experiment results [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Secondly, while the sample size met the requirements of the experiment, a larger sample size would undoubtedly increase the validity of this study.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003eCompared to traditional breath training, low-flow mask oxygenation could be a better treatment for PHVS, especially in emergency ddepatments, with more comfort and faster recovery.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eED\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEmergency department\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eBT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eBreath training\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eLFMO\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eLow-flow mask oxygenation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePHVS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePsychogenic hyperventilation syndrome\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eASI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAnxiety Sensitivity Index\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eABG\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eArterial blood gas\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and analyzed in this study are not publicly available due protect patient privacy but are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study followed the Sex and Gender Equity in Research (SAGER) guidelines\u0026nbsp;and is in line with the Declaration of Helsinki,\u0026nbsp;Participants can freely withdraw from the study without any effect, which is registered in the Chinese Clinical Trial Registry with a definite number ChiCTR2300072044 and approved by the Ethics Committee of Guangyuan Central Hospital (GYZXLL2023070). All participants voluntarily signed the informed consent. All data from this study are confidential and supervised by the Ethics Committee of Guangyuan Central Hospital.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eZYL and DMY: conception, design, the analytical plan, manuscript drafting, and contributed equally to this work. LHY and YYL: data acquisition and data analysis.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgment:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAvest E, Patist FM, Maaten JC, et al. Elevated lactate during psychogenic hyperventilation. Emerg Med J. 2011;28:269\u0026ndash;73.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBoulding R, Stacey R, Niven R, et al. Dysfunctional breathing: A review of the literature and proposal for classification. Eur Respiratory Rev. 2016;25:287\u0026ndash;94.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrussee P, Zwaag J, van Eijk L, et al. Stewart analysis unmasks acidifying and alkalizing effects of ionic shifts during acute severe respiratory alkalosis. J Crit Care. 2021;66:1\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCammarota G, Simonte R, De Robertis E. Comfort During Non-invasive Ventilation. Front Med. 2022;9:874250. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/fmed.2022.874250\u003c/span\u003e\u003cspan address=\"10.3389/fmed.2022.874250\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDerrick K, Green T, Wand T. Assessing and responding to anxiety and panic in the Emergency Department. Australasian Emerg Care. 2019;22:216\u0026ndash;20.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCD, McNally RJ. Anxiety sensitivity and history of panic as predictors of response to hyperventilation. Behav Res Ther. 1989;27:325\u0026ndash;32.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eExpert Consensus Group on Emergency Oxygen Therapy. Expert consensus on emergency oxygen therapy. J Chin Emerg Med. 2018;27:355\u0026ndash;60.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGouzi F, Dubois-Gamez AS, Lacoude P, et al. Feasibility of nasal breathing training during pulmonary rehabilitation, A pilot randomized controlled study. Respir Physiol Neurobiol. 2023;308:103987.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIndranada AM, Mullen SA, Duncan R, Berlowitz DJ, Kanaan RAA. The association of panic and hyperventilation with psychogenic non-epileptic seizures: A systematic review and meta-analysis. Seizure. 2018;59:108\u0026ndash;15. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.seizure.2018.05.007\u003c/span\u003e\u003cspan address=\"10.1016/j.seizure.2018.05.007\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJones M, Harvey A, Marston L, et al. Breathing exercises for dysfunctional breathing/hyperventilation syndrome in adults. Cochrane Database Syst Rev. 2013;5:CD009041.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJulious SA. Sample size of 12 per group rule of thumb for a pilot study. Pharm Stat. 2005;4:287\u0026ndash;91.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMeuret AE, Ritz T, Wilhelm FH, et al. Voluntary hyperventilation in the treatment of panic disorder\u0026mdash;Functions of hyperventilation, their implications for breathing training, and recommendations for standardization. Clin Psychol Rev. 2005;25:285\u0026ndash;306.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOh S, Ha TH, Kim H, et al. Emergency department visits for panic attacks and ambient temperature: A time-stratified case-crossover analysis. Depress Anxiety. 2020;37:1099\u0026ndash;107.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePfortmueller CA, Pauchard-Neuwerth SE, Leichtle AB, et al. Primary Hyperventilation in the Emergency Department: A First Overview. PLoS ONE. 2015;10:e0129562.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSep\u0026uacute;lveda RA, Romero J, Sep\u0026uacute;lveda S, et al. Severe respiratory alkalosis due to psychogenic hyperventilation. Report of one case. Rev Med Chil. 2022;150:554\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTunnell NC, Ritz T, Wilhelm FH, Roth WT, Meuret AE. Habituation or Normalization? Experiential and Respiratory Recovery From Voluntary Hyperventilation in Treated Versus Untreated Patients With Panic Disorder. Behav Ther. 2021;52(1):124\u0026ndash;35. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.beth.2020.03.003\u003c/span\u003e\u003cspan address=\"10.1016/j.beth.2020.03.003\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWatson GM, Sutherland J, Lacey C, et al. A randomized cross-over trial of QT response to hyperventilation-induced anxiety and diaphragmatic breathing in patients with stress cardiomyopathy and in control patients. PLoS ONE. 2022;17:e0265607.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWilliams CYK, Williams RWK, Knight R, et al. Hyperventilation Syndrome: Investigating the Relationship Between Nijmegen Questionnaire, Vestibular Function Tests, and Patient Symptoms. \u003cem\u003eOtology \u0026amp; Neurotology: Official Publication of the American Otological Society\u003c/em\u003e. Am Neurotology Soc [and] Eur Acad Otology Neurotology. 2020;41:e349\u0026ndash;56.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"hyperventilation, low-flow oxygen, breath training, psychogenic hyperventilation","lastPublishedDoi":"10.21203/rs.3.rs-3536139/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3536139/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eObjectives\u003c/h2\u003e \u003cp\u003eTo compare the effect of low-flow mask oxygenation (LFMO) with breathing training (BT) for psychogenic hyperventilation syndrome (PHVS), providing more options and evidence for clinical treatment.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eA double-blind, randomized controlled trial (Registered number: ChiCTR2300072044, June 1, 2023) was conducted in a tertiary hospital from 5 June 2023 to 25 June 2023. Participants were recruited and randomly assigned to the LFMO or BT groups. All participants were guided and presented PHVS, then the LFMO group inhaled 3L/minute oxygen with the oxygen mask, and the BT group took the breath training with 20 breath rate/minute. The length of the recovery from PHVS and the comfort/tolerance score were collected as the primary outcome. and the PH, lactate, K+, Ca2+, PO\u003csub\u003e2\u003c/sub\u003e, and PCo\u003csub\u003e2\u003c/sub\u003e was collected as the secondary outcome.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eForty-four participants completed the study and were included for analysis (21 for the LFMO group and 23 for the BT group), mainly female (75%, n\u0026thinsp;=\u0026thinsp;33). After a period of fast breathing, all participants diagnosed with PHVS by the 1st ABG test (Pco\u003csub\u003e2\u003c/sub\u003e: 27.40\u0026thinsp;\u0026plusmn;\u0026thinsp;3.11; 28.80\u0026thinsp;\u0026plusmn;\u0026thinsp;1.87) and Nijmegen Questionnaire(23.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.66; 23.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.58), and all participants recovered from PHVS after interventions. However, the LFMO group showed significant advantages in both the length of recovery (22.41\u0026thinsp;\u0026plusmn;\u0026thinsp;3.36, p\u0026thinsp;\u0026lt;\u0026thinsp;0.000) and comfort/tolerance (5.85\u0026thinsp;\u0026plusmn;\u0026thinsp;1.23, p\u0026thinsp;=\u0026thinsp;0.011), while no significant difference was detected among secondary outcomes.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eCompared to traditional breath training, low-flow mask oxygenation could be a better treatment for PHVS, especially in emergency departments, with more comfort and faster recovery.\u003c/p\u003e","manuscriptTitle":"The low-flow mask oxygen could be a better treatment for emergency psychogenic hyperventilation syndromes: a double-blind, randomized controlled trial","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-04-17 20:41:26","doi":"10.21203/rs.3.rs-3536139/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"b8ddf89f-6a2d-435d-a302-1eb0b37f34d5","owner":[],"postedDate":"April 17th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-06-10T05:08:44+00:00","versionOfRecord":[],"versionCreatedAt":"2024-04-17 20:41:26","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3536139","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3536139","identity":"rs-3536139","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}