Changes Of Lung Ventilation And Perfusion After Lung Transplantation Based On Electrical Impedance Tomography

Changes Of Lung Ventilation And Perfusion After Lung Transplantation Based On Electrical Impedance Tomography | 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 Changes Of Lung Ventilation And Perfusion After Lung Transplantation Based On Electrical Impedance Tomography Yan Dong, Zhongping XU, Dapeng Wang, Jing Tian, Hongyang Xu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5737031/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 Background Electrical impedance tomography (EIT) based on pulsatility method and the saline bolus injection method has become more mature in recent years. However, clinical studies about the use of EIT in patients after lung transplantation has not emerged. We used EIT to observe the changes of lung ventilation and perfusion after lung transplantation, and combined with blood gas analysis, lung ultrasound score (LUS), and other clinical indicators to evaluate the therapeutic effectiveness of lung transplantation. Methods Patients who received lung transplantation at the Lung Transplant Center of Wuxi People's Hospital affiliated to Nanjing Medical University from December 2023 to January 2024 were included in this retrospective review. Patients were divided into prolonged mechanical ventilation (PMV) group and control group according to whether invasive mechanical ventilation lasted more than 72 hours after surgery. General data, arterial blood gas results, ultrasonic LUS score were recorded. The lungs were divided into region of interest (ROI) 1 to 4. Ventilation and perfusion data of each region during extracorporeal membrane oxygenation (ECMO) combined mechanical ventilation (H1), during mechanical ventilation (H2), and post-extubation (H3) were also recorded. Results 1. Low/high-speed passband index (LHI) during H2 and H3 was significantly higher in control group than in PMV group, with statistical difference (P < 0.05). 2. Center of ventilation (COV) showed a downward trend in postoperative patients, while COV in control group was closer to the gravity-dependent area. 3. At each stage, LUS in PMV group was significantly higher than that in control group, with statistical significance (P < 0.05). Conclusion It is safe and reasonable to use EIT to monitor pulmonary ventilation and perfusion after lung transplantation.The use of relevant EIT parameters (e.g. GI,LHI) can be supplemented with lung relevant information to understand individual patient physiological trends. Electrical impedance tomography Lung transplantation Prolonged mechanical ventilation Figures Figure 1 Figure 2 Introduction Lung transplantation is the most effective treatment modality for end-stage pulmonary disease. The surgeries is complicated and traumatic. Patients often face with extracorporeal membrane oxygenation (ECMO) related complications,ventilator dependence and difficult weaning, which subsequently increases the incidence of iatrogenic lung injury and postoperative lung infection. Therefore, consideration and evaluation of ECMO and ventilator withdrawn should be conducted as soon as possible. It is very important to choose the right ECMO withdrawal and off-line extubation timing. In the clinic, Spontaneous breathing trials (SBT) and the clinician's experience are often used to determine whether the patient is ready for offline extubation[ 1 ]. However, there is a lack of easy-to-use bedside tools that provide visualize and monitor. Recent years, Electrical impedance tomography (EIT) based on pulsatility method and the saline bolus injection method has become more mature. It dynamically displays changes in the corresponding bioimpedance caused by changes in lung function and realizes real-time monitoring of regional pulmonary ventilation and perfusion changes with the same screen which help doctors quickly identify the etiology and develop treatment options. EIT is more timely and intuitive than blood gas analysis and clinical signs. As for EIT, individualizing PEEP to analyze lung reexpansion and avoiding ventilator induced lung injury have become a concern of great interest in various clinical studies[ 2 ]. In addition, other different clinical scenarios, such as single lung ventilation, pulmonary edema, etc., have demonstrated the practicability of EIT. Interestingly, clinical studies about the use of EIT in patients after lung transplantation has not emerged. In the present study, combined with blood gas analysis, lung ultrasound and other clinical indicators, EIT monitoring technology was applied to observe and visually analyze the pulmonary ventilation and perfusion of patients at critical nodes after lung transplantation. It may help o lot in future postoperative management of lung transplantation patients. Materials and methods 1.1 Patients and data collection This was a single-center study in which data for a retrospective analysis were obtained from patients who received lung transplantation at the Lung Transplant Center of Wuxi People's Hospital affiliated to Nanjing Medical University from December 2023 to January 2024. The following were the inclusion criteria: 1. Age > 18; 2. Lung transplantation was performed for the first time and EIT monitoring was performed in ICU. 3. The clinical data were complete. Exclusion criteria included the following: 1. Patients who received ECMO support prior to surgery. 2. Invasive mechanical ventilation with tracheotomy or intubation was used before surgery. 3. EIT images are poor and not suitable for data analysis. We recorded general data, ventilator-related data and blood gas analysis. Ethics: This study was approved by the Clinical New Technology and Research Ethics Committee of Wuxi People's Hospital, affiliated with Nanjing Medical University. Postoperative management of lung transplantation Lung transplant recipients were admitted to the intensive care unit (ICU) with ECMO and tracheal intubation after surgery. According to the occurrence of postoperative graft loss and degree, oxygenation, ECMO spontaneous breathing test results, ECMO removal should be considered for those who meet the conditions. Weaning/extubation depends on the recipient's hemodynamics, respiratory status, lung infection consciousness and muscle strength recovery. All extubated patients passed a weaning assessment and spontaneous breathing trial. 1.3 EIT Data Acquisition and Analysis One appropriate size belt with 16 surface electrodes was placed at the level of the 3rd and 5th intercostal spaces. Data were recorded by an EIT device (Infivision ET1000, CHINA). Lung perfusion was evaluated by pulsatility-based EIT methods. Images of the pulsatility method were generated based on a separated cardiac-related signal. The lungs were divided into region of interest (ROI) 1 to 4. Ventilation and perfusion data of each region during ECMO combined mechanical ventilation, during mechanical ventilation, and post-extubation were also recorded. EIT date include center of ventilation (COV), global inhomogeneity index (GI), lung heterogeneity index (LHI), regional ventilation delay (RVD), the change in compliance change percentage variation (|Δ(CW-CL)|) CoV, which represents the geometrical focal point of the overall ventilation: This index is expressed as a percentage of the anteroposterior extension of the identified lung region, where 0% refers to ventilation occurring only in the most ventral lung region and 100% refers to ventilation in the most dorsal part[ 3 ]. A GI of zero represents a perfect homogenous ventilation distribution; the larger the GI, the more inhomogeneous the tidal volume distribution within the lung area. LHI means ventilation/perfusion matching index. A LHI of 1 indicates that the ventilate blood flow ratio is completely matched, and the smaller the value, the more mismatch between ventilation and perfusion in the lung area. RVD index was used to further analyze regional ventilation distribution. It describes the delay between the impedance reaching a specific impedance threshold from the beginning of inspiration and can be used as a parameter reflecting the distribution of lung ventilation time. It may be associated with regional reexpansion in the lung[ 4 , 5 ]. Δ(CW-CL) is defined as the difference between CW and CL at H2 and H3 and H1. End-expiratory lung impedance and tidal volume ratio (ΔEELI/VT) is defined as the difference between EELI/VT at H2 and H3 and H1. SPSS27.0 software was used for statistical analysis, and normal distribution test was conducted for continuous variables. Measurement data conforming to normal distribution were represented by mean ± standard deviation (± s), and two-independent sample T-test was used for comparison between groups.Measurement data that did not conform to normal distribution were represented by median (lower quartile, upper quartile), and Mann-Whitney U rank sum test was used for inter-group comparison.Categorical variables are expressed as the number of cases and percentage [example (%)], using the chi-square test. Result A total of 26 patients who received lung transplantation were enrolled. There were no dropout cases, and EIT data can be collected for all patients. Patients were divided into prolonged mechanical ventilation(PMV) group and control group according to whether invasive mechanical ventilation lasted more than 72 hours after surgery. All patients were treated with ECMO and invasive mechanical ventilation, and no secondary tracheal intubation was performed after off-line extubation. There were no statistically significant differences in age, gender, APACH II score and mode of surgery between the two groups (P > 0.05). The cold ischemia time and length of ICU stay in PMV group were significantly longer (p < 0.05) (Table 1 ). Table 1 Baseline characteristics of patient All(n = 26) PMV(n = 9) NPMV(n = 17) P-values: PMVverusNPMV Age, years 58(56.00,62.00) 58(57.90,63) 57.5(54.50,61.25) 0.81 Male sex, n (%) 19(73.08) 7(77.78) 12(70.59) 0.99 BMI 21.67 ± 4.18 23.01 ± 3.18 20.17 ± 4.85 0.18 APACH II 15.50(13.75,19.75) 19.00(16.25,22.50) 15.00(12.75,15.25) 0.08 SOFA 10.56 ± 2.90 11.88 ± 2.53 9.25 ± 2.76 0.06 Type of transplant(unilateral), n༈%༉ 5(19.23) 1(11.11) 4(23.53) 0.58 Cold ischemia time(min) 582.38 ± 71.05 608.49 ± 62.57 553.00 ± 72.12 0.04 Type of ECMO VV, n(%) 23(88.46) 6(66.67) 17(100) VA, n(%) 2(7.69) 2(22.22) 0(0) VAV, n(%) 1(3.85) 1(11.11) 0(0) ECMO blood flow 2.43 (2.26, 2.63) 2.46 (2.37, 2.63) 2.27 (1.97, 2.61) 0.17 术后ECMO时间(H) 29.01(16.50, 61.70) 61.70(41.50,68.00) 16.25(14.88,17.48) < 0.01 Length of MV (hours) 70.08(41.00, 117.00) 117.00(92.50,280.80) 62.25(40.38,71.25) < 0.01 Length of ICU (hours) 140.39(63.50, 208.93) 185.43(168.61,309.50) 62.25(40.38,81.25) < 0.01 Arterial blood gas index values, static compliance and LUS scores are shown in Table 2 . PaO2/FiO2 in the control group was significantly higher than that in the PMV group at both the H1 and the H2. There was no significant difference in other arterial blood gas indexes between the two groups at the individual stages. At all time points, LUS scores in PMV group were significantly higher than those in control group, with statistical significance (p < 0.05). Table 2 Blood gas and respiratory data analysis All(n = 26) PMV(n = 9) NPMV(n = 17) P-values: PMVverusNPMV PaCO2, kPa H1 37.16 ± 6.39 38.80 ± 6.98 35.51 ± 5.70 0.32 H2 43.00(34.70,45.50) 45.40(40.20,47.30) 38.85(32.73,45.50) 0.31 H3 44.60(38.60,47.30) 38.60(34.80,42.55) 46.40(44.05,47.40) 0.23 Lactate, mmol/L H1 2.90(2.17,4.55) 2.70(1.78,3.15) 3.85(2.30,4.75) 0.27 H2 1.70(1.40,2.20) 1.50(1.40,1.70) 2.15(1.55,2.20) 0.34 H3 1.62 ± 0.75 1.20 ± 0.45 1.86 ± 0.81 0.18 PaO2/FiO2 H1 316.25 ± 114.94 249.38 ± 87.97 383.12 ± 101.73 0.01 H2 344.38 ± 125.24 225.00 ± 73.88 419.00 ± 85.02 0.01 H3 299.87 ± 135.76 225.75 ± 55.90 342.23 ± 152.97 0.18 Cst H1 31.69 ± 6.76 30.83 ± 7.34 32.65 ± 6.40 0.59 H2 33.94 ± 7.89 32.64 ± 9.13 35.41 ± 6.53 0.47 H3 36.97 ± 9.45 34.80 ± 9.87 38.89 ± 9.20 0.39 LUS H1 5.50 ± 1.34 6.22 ± 1.39 4.58 ± 0.74 < 0.01 H2 4.27 (3.96, 6.00) 6.00 (4.50, 6.50) 3.98 (3.38, 4.07) < 0.01 H3 3.27 (3.00, 4.36) 4.36 (3.50, 5.00) 3.00 (2.85, 3.20) 0.01 Table 3 shows the EIT parameters during SBT. GI, as a marker of inhomogeneity of gas distribution within the lungs, was higher in the PMV group relative to the control group during H1 and H2(68.76 ± 5.52vs.64.53 ± 2.34, p = 0.03;67.25 ± 4.35vs.63.20 ± 4.09, p = 0.04). LHI, representing ventilation and perfusion matching, was higher in PMV group at each stage, with statistical difference (P < 0.05). COV, RVD, derived data from EIT [△(CW-CL), △EELI/VT] did not show significant difference. However, the COV showed a decreasing trend in postoperative patients(Fig. 1 A), and was closer to the gravity-dependent region in control group(Figure 2 A). Table 3 respiratory data, blood gas and LUS analysis All(n = 26) PMV(n = 9) NPMV(n = 17) P-values:PMVverusNPMV COV(%) H1 53.18 (52.00, 58.00) 58.00 (52.00, 68.00) 53.06 (51.25, 55.08) 0.19 H2 52.00 (51.67, 52.47) 51.97 (51.81, 52.19) 52.17 (51.00, 52.67) 0.73 H3 48.70 ± 2.12 48.33 ± 3.51 49.40 ± 3.21 0.68 GI(%) H1 66.78 ± 3.95 68.76 ± 5.52 64.53 ± 2.34 0.03 H2 65.97 ± 2.90 67.25 ± 4.35 63.20 ± 4.09 0.04 H3 64.33 ± 3.19 68.00 ± 8.15 61.33 ± 2.73 0.11 LHI(%) H1 80.00 (70.70, 82.00) 76.00 (67.00, 82.00) 81.00 (78.75, 82.00) 0.03 H2 81.20 (76.00, 85.00) 76.40 (64.60, 81.20) 85.25 (82.43, 85.25) 0.03 H3 83.47 (77.40, 90.00) 77.40 (71.00, 83.47) 89.50 (86.00, 91.00) 0.02 RVD H1 11.34 (5.30, 13.07) 13.07 (7.50, 21.80) 11.02 (4.30, 11.54) 0.29 H2 13.61 ± 9.75 15.59 ± 10.52 11.84 ± 9.26 0.24 H3 9.75 (9.16, 10.30) 9.93 (9.36, 10.22) 9.29 (7.96, 10.31) 0.36 |△(CW-CL)| H1 - - - - H2 12.73 (5.50, 20.00) 20.00 (5.91, 25.00) 7.75 (5.39, 13.42) 0.17 H3 12.00 (5.97, 23.58) 20.50 (5.97, 24.50) 8.81 (6.04, 14.88) 0.39 △EELI/VT H1 - - - - H2 0.37 (-0.23, 0.48) 0.02(-0.15,0.07) 0.23 (0.17, 0.51) 0.42 H3 0.43 ± 1.19 0.43 ± 0.14 0.79 ± 1.17 0.31 Discussion In this study of patients after lung transplantation, EIT was applied as an observational tool. This study found that compared with the control group, the LHI, △EELI/VT were lower and the GI, RVD and △CW-CL were higher in the PMV group, although not all of them were statistically significant. Lung transplantation is the only life-prolonging treatment option for patients with end-stage lung disease. Survival rates for lung transplants have improved dramatically over the past few decades. However, the patient's condition is more complex and changeable, often combined with a variety of underlying diseases. Early withdrawal of ECMO and extubation have become the main treatment goals in the ICU after surgery, which can reduce the adverse effects of ECMO-related complications, ventilator-related lung injury, infection, and muscle weakness. Studies have shown that intraoperative and transitional use of ECMO can reduce perioperative complications, shorten ICU stay, and improve survival in patients with double lung transplantation[ 6 , 7 ]. Some previous studies defined PMV after lung transplantation as mechanical ventilation for more than 72 hours, as they found that most patients (68.1%, 77.1%, and 80.6%, respectively) had extubed offline at 72 hours[ 8 – 10 ]. In this study, although ECMO application may extend mechanical ventilation time, we observed similar extubation rates in the first 72 hours after transplantation (17/26, 65.4%). Therefore, we defined PMV using the same criteria as the studies mentioned earlier. PMV has been shown to be a predictor of poor short-term prognosis and impaired long-term survival after lung transplantation. EIT can be used as an auxiliary bedside tool to monitor changes in regional ventilation and perfusion distribution of patients after lung transplantation. EIT can be used as an auxiliary bedside tool to monitor the changes of ventilation and perfusion distribution in various areas of the lung after lung transplantation. As a result, EIT may be helpful for clinicians to analyze patients' breathing status and thus adjust clinical decisions. In our research, we observed an interesting phenomenon that COV in the PMV group at ICU admission appears to be closer to the gravity-dependent zone than in the control group. We think this may be related to the preservation and transportation of the donor lung. During mechanical ventilation, the initial airway pressure increase causes the gas to enter the gravity-independent zone, and then the gas is redistributed and gradually distributed into the gravity-dependent zone. Due to the different cold ischemia time of the donor lung and the different degree of ischemia-reperfusion injury, the distribution of ventilation centers is more irregular. GI describes the spatial heterogeneity of pulmonary ventilation. Bickenbach et al. found in their study on postoperative heart surgery that patients with GI > 40 were more likely to have SBT failure[ 4 ]. As our study shows, patients with prolonged mechanical ventilation have a higher GI index, that is, a more uneven distribution of gas in the lungs and a lower alveolar ventilation volume. As our study shows, patients with prolonged mechanical ventilation have a higher GI index, meaning more uneven gas distribution in the lungs and lower alveolar ventilation. LHI index introduces perfusion evaluation index on the basis of GI index.At any time, the LHI index in the PMV group was consistently lower than that in the control group, reflecting a poorer pulmonary ventilation flow match in the PMV group. The RVD index, which is generated for slow inflating during MV[ 11 ], was used by Blankman et al. for the PEEP setting of patients receiving controlled MV[ 2 ], and Wrigge et al for the acute lung injury experimental study[ 5 ]. Although the difference in RVD between our two groups was not statistically significant, the PMV group had a higher RVD index during mechanical ventilation, which may be meaningful in quantifying temporal and spatial inhomogeneity. △EELI indicates changes in end-expiratory pulmonary impedance at different time points after lung transplantation. The decrease in △EELI indicates possible partial alveolar collapse or VT decrease[ 12 ]. Since EELI is affected by VT, we also chose to use △EELI/VT to reduce this unevenness.Huang et al. found that △EELI/VT could predict the success rate of withdrawal after upper abdominal surgery, and △EELI/VT was greater in patients who failed to withdraw during STB.Our study also had similar results. After treatment, collapsed alveoli in lung transplant patients gradually opened and △EELI/VT gradually increased, but the increase in PMV patients was worse than that in control group. A key role of lung protective ventilation after lung transplantation is to redistribute ventilation to the lung dependent area, providing more even ventilation to the patient. However, the degree and distribution of alveolar collapse caused by ischemia-reperfusion injury in donor lungs vary greatly among individuals. Ultrasound-based lung LUS scores also show some potential in detecting alveolar collapse and edema. PGD involves tissue inflammation and fluid-filled alveoli in a heterogeneous distribution; thus, some areas are well aerated and others collapse or fill with fluid and inflammatory cells. Such dense tissue may behave less like a fluid and more as a frame of solid areas resisting shape deformation. In brief, the phenomenon occurs because, in contrast to normal lung, the injured lung does not exhibit fluid like behavior. Even if the tidal volume of the ventilator is limited to less than 6ml/kg, there will be excessive stretching of the lungs in some areas due to swinging breathing. As a result, EIT can be used to monitor in real time the increasing regional inhomogeneity and deduplication of the lungs.In addition, it is different from the instantaneous examination such as chest film and bedside bronchoscopy, which is more conducive to the whole-process monitoring and evaluation of patients. It has been proved that the monitoring results of EIT perfusion imaging also have a good correlation with the anatomical structure and CT scan results corresponding to blood flow changes. Zhang et al. found that during VV-ECMO, the ECMO blood flow rate, closely related to recirculation fraction, which will have a stronger influence on the distribution of bolus saline across the regional lung, thus affecting the accuracy of lung perfusion assessment using hypertonic saline bolus-based EIT[ 13 ]. Therefore, EIT has shown certain advantages and potential in the evaluation of perfusion. This work has some limitations. First, our study was carried out in a single center, and a small number of patients were included. Second, changes in the position of the electrode band can significantly affect the results of the EIT, which increases the uncertainty when analyzing the data. Third, EIT results do not fully explain the anatomical changes that lead to ventilation and perfusion, and small pulmonary changes may not cause significant changes in local perfusion or ventilation. The role of EIT in monitoring lung function after lung transplantation needs to be further confirmed by multi-center studies with large sample size. Conclusion Our study shows that it is safe and reasonable for patients after lung transplantation to use EIT to monitor lung ventilation and perfusion. The use of relevant EIT parameters (such as GI and LHI) can supplement the relevant lung conditions and understand the physiological trends of individual patients, which may help clinicians make more accurate clinical decisions in the future. Abbreviations ECMO Extracorporeal membrane oxygenation SBT Spontaneous breathing trials EIT Electrical impedance tomography ICU Intensive care unit ROI Region of interest COV Center of ventilation GI Global inhomogeneity index LHI Lung heterogeneity index RVD Regional ventilation delay △(CW-CL) The change in compliance change percentage variation △EELI/VT End-expiratory lung impedance and tidal volume ratio PMV Prolonged mechanical ventilation Declarations Acknowledgements Not applicable. Author contributions All authors contributed to this case report. All provided input and critique on the final manuscript. Funding This case report was financially supported by no funding. Data availability The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions. Ethics approval and consent to participate The Institutional Ethics Committees of Wuxi People’s Hospital affiliated to Nanjing Medical University approved this study. Informed consents in written form were obtained from the patients or their next of kin in written. Consent for publication Written informed consent was obtained from the patients for publication of this article. Competing interests The authors declare no competing interests. References Thille, A.W., et al., Spontaneous-Breathing Trials with Pressure-Support Ventilation or a T-Piece. N Engl J Med, 2022. 387(20): p. 1843-1854. Blankman, P., et al., Detection of 'best' positive end-expiratory pressure derived from electrical impedance tomography parameters during a decremental positive end-expiratory pressure trial. 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Intensive Care Med, 2021. 47(11): p. 1181-1247. Schwarz, S., et al., Ventilation parameters and early graft function in double lung transplantation. J Heart Lung Transplant, 2021. 40(1): p. 4-11. Pilcher, D.V., et al., High central venous pressure is associated with prolonged mechanical ventilation and increased mortality after lung transplantation. J Thorac Cardiovasc Surg, 2005. 129(4): p. 912-8. Gao, P., et al., Establishment of a risk prediction model for prolonged mechanical ventilation after lung transplantation: a retrospective cohort study. BMC Pulm Med, 2023. 23(1): p. 11. Zhao, Z., et al., PEEP titration guided by ventilation homogeneity: a feasibility study using electrical impedance tomography. Crit Care, 2010. 14(1): p. R8. Li, J., et al., Electrical Impedance Tomography Predicts Weaning Success in Adult Patients With Delayed Upper Abdominal Surgery: A Single-Center Retrospective Study. Front Med (Lausanne), 2021. 8(2): p. 748493. Zhang, H., et al., Effects of different VV ECMO blood flow rates on lung perfusion assessment by hypertonic saline bolus-based electrical impedance tomography. Crit Care, 2024. 28(1): p. 274. Additional Declarations No competing interests reported. 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. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5737031","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":396221850,"identity":"e42b9588-5be6-4256-a518-9248dccab4b5","order_by":0,"name":"Yan Dong","email":"","orcid":"","institution":"The Affiliated Wuxi People’s Hospital of Nanjing Medical University, Nanjing Medical University","correspondingAuthor":false,"prefix":"","firstName":"Yan","middleName":"","lastName":"Dong","suffix":""},{"id":396221851,"identity":"f460f44c-39f1-4935-8db3-1906dc57a075","order_by":1,"name":"Zhongping XU","email":"","orcid":"","institution":"The Affiliated Wuxi People’s Hospital of Nanjing Medical University, Nanjing Medical University","correspondingAuthor":false,"prefix":"","firstName":"Zhongping","middleName":"","lastName":"XU","suffix":""},{"id":396221852,"identity":"c79947b1-c0d6-4efa-acd2-905d1789188a","order_by":2,"name":"Dapeng Wang","email":"","orcid":"","institution":"The Affiliated Wuxi People’s Hospital of Nanjing Medical University, Nanjing Medical University","correspondingAuthor":false,"prefix":"","firstName":"Dapeng","middleName":"","lastName":"Wang","suffix":""},{"id":396221853,"identity":"2b582eb4-2b9b-4b3f-a916-81a2e9b11d72","order_by":3,"name":"Jing Tian","email":"","orcid":"","institution":"The Affiliated Wuxi People’s Hospital of Nanjing Medical University, Nanjing Medical University","correspondingAuthor":false,"prefix":"","firstName":"Jing","middleName":"","lastName":"Tian","suffix":""},{"id":396221854,"identity":"5840d272-0277-404e-9a45-0db2ee7bcaaa","order_by":4,"name":"Hongyang Xu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA1ElEQVRIiWNgGAWjYDACCQaGAx8MbOQY2BkbiNbCeHBGQZoxAzMJWpgP83w4nNjATKy7DG73GBzmMWBO729mbpPm3cEgzy92AL8WyTlnDA7OMWDLnXGYEajlDIPhzNkJ+LXwS+QYHHhjwJPbANbSxpBgcJuAFjaQFh4DiXR5orWAbDnIY2CQYEC0FskZaQUHZxgkGG48zNhsObdNgrBfDG4kb/7w4c9/ebnj7Q9vvG2zkeeXJqCFgYHDAMZikQAnBsKA/QGMxfyBGPWjYBSMglEw8gAATaxCuMTg2C4AAAAASUVORK5CYII=","orcid":"","institution":"The Affiliated Wuxi People’s Hospital of Nanjing Medical University, Nanjing Medical University","correspondingAuthor":true,"prefix":"","firstName":"Hongyang","middleName":"","lastName":"Xu","suffix":""}],"badges":[],"createdAt":"2024-12-30 16:53:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5737031/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5737031/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":72800864,"identity":"52c15a7a-70c4-4245-8765-44ffbb46ab09","added_by":"auto","created_at":"2025-01-02 09:27:51","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":7823,"visible":true,"origin":"","legend":"\u003cp\u003eLegend not included with this version\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-5737031/v1/c6e1afc12d55e00a7c1ddb09.png"},{"id":72800862,"identity":"22874c93-9520-4b6b-b410-f6d7f1978d84","added_by":"auto","created_at":"2025-01-02 09:27:50","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":8453,"visible":true,"origin":"","legend":"\u003cp\u003eLegend not included with this version\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-5737031/v1/f37c9b98fadea99a39fcbfbf.png"},{"id":74550182,"identity":"da496a02-4702-460d-b5dd-2b59c984d202","added_by":"auto","created_at":"2025-01-23 10:39:16","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":667935,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5737031/v1/783ced16-781f-4648-8538-a7b232802882.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Changes Of Lung Ventilation And Perfusion After Lung Transplantation Based On Electrical Impedance Tomography","fulltext":[{"header":"Introduction","content":"\u003cp\u003eLung transplantation is the most effective treatment modality for end-stage pulmonary disease. The surgeries is complicated and traumatic. Patients often face with extracorporeal membrane oxygenation (ECMO) related complications,ventilator dependence and difficult weaning, which subsequently increases the incidence of iatrogenic lung injury and postoperative lung infection. Therefore, consideration and evaluation of ECMO and ventilator withdrawn should be conducted as soon as possible. It is very important to choose the right ECMO withdrawal and off-line extubation timing. In the clinic, Spontaneous breathing trials (SBT) and the clinician's experience are often used to determine whether the patient is ready for offline extubation[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. However, there is a lack of easy-to-use bedside tools that provide visualize and monitor.\u003c/p\u003e \u003cp\u003eRecent years, Electrical impedance tomography (EIT) based on pulsatility method and the saline bolus injection method has become more mature. It dynamically displays changes in the corresponding bioimpedance caused by changes in lung function and realizes real-time monitoring of regional pulmonary ventilation and perfusion changes with the same screen which help doctors quickly identify the etiology and develop treatment options. EIT is more timely and intuitive than blood gas analysis and clinical signs. As for EIT, individualizing PEEP to analyze lung reexpansion and avoiding ventilator induced lung injury have become a concern of great interest in various clinical studies[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. In addition, other different clinical scenarios, such as single lung ventilation, pulmonary edema, etc., have demonstrated the practicability of EIT.\u003c/p\u003e \u003cp\u003eInterestingly, clinical studies about the use of EIT in patients after lung transplantation has not emerged. In the present study, combined with blood gas analysis, lung ultrasound and other clinical indicators, EIT monitoring technology was applied to observe and visually analyze the pulmonary ventilation and perfusion of patients at critical nodes after lung transplantation. It may help o lot in future postoperative management of lung transplantation patients.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e1.1 Patients and data collection\u003c/h2\u003e \u003cp\u003e This was a single-center study in which data for a retrospective analysis were obtained from patients who received lung transplantation at the Lung Transplant Center of Wuxi People's Hospital affiliated to Nanjing Medical University from December 2023 to January 2024. The following were the inclusion criteria: 1. Age \u0026gt; 18; 2. Lung transplantation was performed for the first time and EIT monitoring was performed in ICU. 3. The clinical data were complete. Exclusion criteria included the following: 1. Patients who received ECMO support prior to surgery. 2. Invasive mechanical ventilation with tracheotomy or intubation was used before surgery. 3. EIT images are poor and not suitable for data analysis. We recorded general data, ventilator-related data and blood gas analysis.\u003c/p\u003e \u003cp\u003e Ethics: This study was approved by the Clinical New Technology and Research Ethics Committee of Wuxi People's Hospital, affiliated with Nanjing Medical University.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003ePostoperative management of lung transplantation\u003c/h3\u003e\n\u003cp\u003eLung transplant recipients were admitted to the intensive care unit (ICU) with ECMO and tracheal intubation after surgery. According to the occurrence of postoperative graft loss and degree, oxygenation, ECMO spontaneous breathing test results, ECMO removal should be considered for those who meet the conditions. Weaning/extubation depends on the recipient's hemodynamics, respiratory status, lung infection consciousness and muscle strength recovery. All extubated patients passed a weaning assessment and spontaneous breathing trial.\u003c/p\u003e\n\u003ch3\u003e1.3 EIT Data Acquisition and Analysis\u003c/h3\u003e\n\u003cp\u003eOne appropriate size belt with 16 surface electrodes was placed at the level of the 3rd and 5th intercostal spaces. Data were recorded by an EIT device (Infivision ET1000, CHINA). Lung perfusion was evaluated by pulsatility-based EIT methods. Images of the pulsatility method were generated based on a separated cardiac-related signal.\u003c/p\u003e \u003cp\u003eThe lungs were divided into region of interest (ROI) 1 to 4. Ventilation and perfusion data of each region during ECMO combined mechanical ventilation, during mechanical ventilation, and post-extubation were also recorded. EIT date include center of ventilation (COV), global inhomogeneity index (GI), lung heterogeneity index (LHI), regional ventilation delay (RVD), the change in compliance change percentage variation (|Δ(CW-CL)|)\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003col\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eCoV, which represents the geometrical focal point of the overall ventilation: This index is expressed as a percentage of the anteroposterior extension of the identified lung region, where 0% refers to ventilation occurring only in the most ventral lung region and 100% refers to ventilation in the most dorsal part[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eA GI of zero represents a perfect homogenous ventilation distribution; the larger the GI, the more inhomogeneous the tidal volume distribution within the lung area.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eLHI means ventilation/perfusion matching index. A LHI of 1 indicates that the ventilate blood flow ratio is completely matched, and the smaller the value, the more mismatch between ventilation and perfusion in the lung area.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eRVD index was used to further analyze regional ventilation distribution. It describes the delay between the impedance reaching a specific impedance threshold from the beginning of inspiration and can be used as a parameter reflecting the distribution of lung ventilation time. It may be associated with regional reexpansion in the lung[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eΔ(CW-CL) is defined as the difference between CW and CL at H2 and H3 and H1.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eEnd-expiratory lung impedance and tidal volume ratio (ΔEELI/VT) is defined as the difference between EELI/VT at H2 and H3 and H1.\u003c/p\u003e\u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003cp\u003eSPSS27.0 software was used for statistical analysis, and normal distribution test was conducted for continuous variables. Measurement data conforming to normal distribution were represented by mean ± standard deviation (± s), and two-independent sample T-test was used for comparison between groups.Measurement data that did not conform to normal distribution were represented by median (lower quartile, upper quartile), and Mann-Whitney U rank sum test was used for inter-group comparison.Categorical variables are expressed as the number of cases and percentage [example (%)], using the chi-square test.\u003c/p\u003e "},{"header":"Result","content":"\u003cp\u003eA total of 26 patients who received lung transplantation were enrolled. There were no dropout cases, and EIT data can be collected for all patients. Patients were divided into prolonged mechanical ventilation(PMV) group and control group according to whether invasive mechanical ventilation lasted more than 72 hours after surgery.\u003c/p\u003e\u003cp\u003eAll patients were treated with ECMO and invasive mechanical ventilation, and no secondary tracheal intubation was performed after off-line extubation. There were no statistically significant differences in age, gender, APACH II score and mode of surgery between the two groups (P \u0026gt; 0.05). The cold ischemia time and length of ICU stay in PMV group were significantly longer (p \u0026lt; 0.05) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\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\u003eBaseline characteristics of patient\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAll(n = 26)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePMV(n = 9)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNPMV(n = 17)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eP-values:\u003c/p\u003e \u003cp\u003ePMVverusNPMV\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge, years\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e58(56.00,62.00)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e58(57.90,63)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e57.5(54.50,61.25)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.81\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale sex, n (%)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e19(73.08)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e7(77.78)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12(70.59)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.99\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=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e21.67 ± 4.18\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e23.01 ± 3.18\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20.17 ± 4.85\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.18\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAPACH II\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e15.50(13.75,19.75)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e19.00(16.25,22.50)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15.00(12.75,15.25)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.08\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSOFA\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e10.56 ± 2.90\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e11.88 ± 2.53\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9.25 ± 2.76\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.06\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType of transplant(unilateral), n༈%༉\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5(19.23)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1(11.11)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4(23.53)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.58\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCold ischemia time(min)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e582.38 ± 71.05\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e608.49 ± 62.57\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e553.00 ± 72.12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType of ECMO\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=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVV, n(%)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e23(88.46)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6(66.67)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17(100)\u003c/p\u003e \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\u003eVA, n(%)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2(7.69)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2(22.22)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0(0)\u003c/p\u003e \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\u003eVAV, n(%)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1(3.85)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1(11.11)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0(0)\u003c/p\u003e \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\u003eECMO blood flow\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.43 (2.26, 2.63)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.46 (2.37, 2.63)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.27 (1.97, 2.61)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.17\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e术后ECMO时间(H)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e29.01(16.50, 61.70)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e61.70(41.50,68.00)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e16.25(14.88,17.48)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt; 0.01\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLength of MV (hours)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e70.08(41.00, 117.00)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e117.00(92.50,280.80)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e62.25(40.38,71.25)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt; 0.01\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLength of ICU (hours)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e140.39(63.50, 208.93)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e185.43(168.61,309.50)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e62.25(40.38,81.25)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt; 0.01\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003eArterial blood gas index values, static compliance and LUS scores are shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. PaO2/FiO2 in the control group was significantly higher than that in the PMV group at both the H1 and the H2. There was no significant difference in other arterial blood gas indexes between the two groups at the individual stages. At all time points, LUS scores in PMV group were significantly higher than those in control group, with statistical significance (p \u0026lt; 0.05).\u003c/p\u003e\u003cdiv class=\"gridtable\"\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=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\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\u003eBlood gas and respiratory data analysis\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAll(n = 26)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePMV(n = 9)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNPMV(n = 17)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eP-values:\u003c/p\u003e \u003cp\u003ePMVverusNPMV\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePaCO2, kPa\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=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e37.16 ± 6.39\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e38.80 ± 6.98\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e35.51 ± 5.70\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.32\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e43.00(34.70,45.50)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e45.40(40.20,47.30)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e38.85(32.73,45.50)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.31\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e44.60(38.60,47.30)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e38.60(34.80,42.55)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e46.40(44.05,47.40)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.23\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLactate, mmol/L\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=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.90(2.17,4.55)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.70(1.78,3.15)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.85(2.30,4.75)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.27\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.70(1.40,2.20)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.50(1.40,1.70)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.15(1.55,2.20)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.34\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.62 ± 0.75\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.20 ± 0.45\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.86 ± 0.81\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.18\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePaO2/FiO2\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=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e316.25 ± 114.94\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e249.38 ± 87.97\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e383.12 ± 101.73\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e344.38 ± 125.24\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e225.00 ± 73.88\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e419.00 ± 85.02\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e299.87 ± 135.76\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e225.75 ± 55.90\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e342.23 ± 152.97\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.18\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCst\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=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31.69 ± 6.76\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30.83 ± 7.34\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e32.65 ± 6.40\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.59\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33.94 ± 7.89\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.64 ± 9.13\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e35.41 ± 6.53\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.47\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e36.97 ± 9.45\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e34.80 ± 9.87\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e38.89 ± 9.20\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.39\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLUS\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=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5.50 ± 1.34\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.22 ± 1.39\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.58 ± 0.74\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt; 0.01\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.27 (3.96, 6.00)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.00 (4.50, 6.50)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.98 (3.38, 4.07)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt; 0.01\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.27 (3.00, 4.36)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.36 (3.50, 5.00)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.00 (2.85, 3.20)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows the EIT parameters during SBT. GI, as a marker of inhomogeneity of gas distribution within the lungs, was higher in the PMV group relative to the control group during H1 and H2(68.76 ± 5.52vs.64.53 ± 2.34, p = 0.03;67.25 ± 4.35vs.63.20 ± 4.09, p = 0.04). LHI, representing ventilation and perfusion matching, was higher in PMV group at each stage, with statistical difference (P \u0026lt; 0.05). COV, RVD, derived data from EIT [△(CW-CL), △EELI/VT] did not show significant difference. However, the COV showed a decreasing trend in postoperative patients(Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA), and was closer to the gravity-dependent region in control group(Figure\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA).\u003c/p\u003e\u003cdiv class=\"gridtable\"\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=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003erespiratory data, blood gas and LUS analysis\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAll(n = 26)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePMV(n = 9)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNPMV(n = 17)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eP-values:PMVverusNPMV\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOV(%)\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=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e53.18 (52.00, 58.00)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e58.00 (52.00, 68.00)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e53.06 (51.25, 55.08)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.19\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e52.00 (51.67, 52.47)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e51.97 (51.81, 52.19)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e52.17 (51.00, 52.67)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.73\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e48.70 ± 2.12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e48.33 ± 3.51\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e49.40 ± 3.21\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.68\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGI(%)\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=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e66.78 ± 3.95\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e68.76 ± 5.52\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e64.53 ± 2.34\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.03\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e65.97 ± 2.90\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e67.25 ± 4.35\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e63.20 ± 4.09\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e64.33 ± 3.19\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e68.00 ± 8.15\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e61.33 ± 2.73\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.11\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLHI(%)\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=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e80.00 (70.70, 82.00)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e76.00 (67.00, 82.00)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e81.00 (78.75, 82.00)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.03\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e81.20 (76.00, 85.00)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e76.40 (64.60, 81.20)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e85.25 (82.43, 85.25)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.03\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e83.47 (77.40, 90.00)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e77.40 (71.00, 83.47)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e89.50 (86.00, 91.00)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRVD\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=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11.34 (5.30, 13.07)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.07 (7.50, 21.80)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11.02 (4.30, 11.54)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.29\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13.61 ± 9.75\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15.59 ± 10.52\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11.84 ± 9.26\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.24\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9.75 (9.16, 10.30)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.93 (9.36, 10.22)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9.29 (7.96, 10.31)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.36\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e|△(CW-CL)|\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=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12.73 (5.50, 20.00)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20.00 (5.91, 25.00)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.75 (5.39, 13.42)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.17\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12.00 (5.97, 23.58)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20.50 (5.97, 24.50)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.81 (6.04, 14.88)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.39\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e△EELI/VT\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=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.37 (-0.23, 0.48)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.02(-0.15,0.07)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.23 (0.17, 0.51)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.42\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.43 ± 1.19\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.43 ± 0.14\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.79 ± 1.17\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.31\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this study of patients after lung transplantation, EIT was applied as an observational tool. This study found that compared with the control group, the LHI, △EELI/VT were lower and the GI, RVD and △CW-CL were higher in the PMV group, although not all of them were statistically significant. Lung transplantation is the only life-prolonging treatment option for patients with end-stage lung disease. Survival rates for lung transplants have improved dramatically over the past few decades. However, the patient's condition is more complex and changeable, often combined with a variety of underlying diseases. Early withdrawal of ECMO and extubation have become the main treatment goals in the ICU after surgery, which can reduce the adverse effects of ECMO-related complications, ventilator-related lung injury, infection, and muscle weakness. Studies have shown that intraoperative and transitional use of ECMO can reduce perioperative complications, shorten ICU stay, and improve survival in patients with double lung transplantation[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Some previous studies defined PMV after lung transplantation as mechanical ventilation for more than 72 hours, as they found that most patients (68.1%, 77.1%, and 80.6%, respectively) had extubed offline at 72 hours[\u003cspan additionalcitationids=\"CR9\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. In this study, although ECMO application may extend mechanical ventilation time, we observed similar extubation rates in the first 72 hours after transplantation (17/26, 65.4%). Therefore, we defined PMV using the same criteria as the studies mentioned earlier. PMV has been shown to be a predictor of poor short-term prognosis and impaired long-term survival after lung transplantation.\u003c/p\u003e \u003cp\u003eEIT can be used as an auxiliary bedside tool to monitor changes in regional ventilation and perfusion distribution of patients after lung transplantation. EIT can be used as an auxiliary bedside tool to monitor the changes of ventilation and perfusion distribution in various areas of the lung after lung transplantation. As a result, EIT may be helpful for clinicians to analyze patients' breathing status and thus adjust clinical decisions.\u003c/p\u003e \u003cp\u003eIn our research, we observed an interesting phenomenon that COV in the PMV group at ICU admission appears to be closer to the gravity-dependent zone than in the control group. We think this may be related to the preservation and transportation of the donor lung. During mechanical ventilation, the initial airway pressure increase causes the gas to enter the gravity-independent zone, and then the gas is redistributed and gradually distributed into the gravity-dependent zone. Due to the different cold ischemia time of the donor lung and the different degree of ischemia-reperfusion injury, the distribution of ventilation centers is more irregular.\u003c/p\u003e \u003cp\u003eGI describes the spatial heterogeneity of pulmonary ventilation. Bickenbach et al. found in their study on postoperative heart surgery that patients with GI\u0026thinsp;\u0026gt;\u0026thinsp;40 were more likely to have SBT failure[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. As our study shows, patients with prolonged mechanical ventilation have a higher GI index, that is, a more uneven distribution of gas in the lungs and a lower alveolar ventilation volume. As our study shows, patients with prolonged mechanical ventilation have a higher GI index, meaning more uneven gas distribution in the lungs and lower alveolar ventilation. LHI index introduces perfusion evaluation index on the basis of GI index.At any time, the LHI index in the PMV group was consistently lower than that in the control group, reflecting a poorer pulmonary ventilation flow match in the PMV group. The RVD index, which is generated for slow inflating during MV[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], was used by Blankman et al. for the PEEP setting of patients receiving controlled MV[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e], and Wrigge et al for the acute lung injury experimental study[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Although the difference in RVD between our two groups was not statistically significant, the PMV group had a higher RVD index during mechanical ventilation, which may be meaningful in quantifying temporal and spatial inhomogeneity. △EELI indicates changes in end-expiratory pulmonary impedance at different time points after lung transplantation. The decrease in △EELI indicates possible partial alveolar collapse or VT decrease[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Since EELI is affected by VT, we also chose to use △EELI/VT to reduce this unevenness.Huang et al. found that △EELI/VT could predict the success rate of withdrawal after upper abdominal surgery, and △EELI/VT was greater in patients who failed to withdraw during STB.Our study also had similar results. After treatment, collapsed alveoli in lung transplant patients gradually opened and △EELI/VT gradually increased, but the increase in PMV patients was worse than that in control group.\u003c/p\u003e \u003cp\u003eA key role of lung protective ventilation after lung transplantation is to redistribute ventilation to the lung dependent area, providing more even ventilation to the patient. However, the degree and distribution of alveolar collapse caused by ischemia-reperfusion injury in donor lungs vary greatly among individuals. Ultrasound-based lung LUS scores also show some potential in detecting alveolar collapse and edema. PGD involves tissue inflammation and fluid-filled alveoli in a heterogeneous distribution; thus, some areas are well aerated and others collapse or fill with fluid and inflammatory cells. Such dense tissue may behave less like a fluid and more as a frame of solid areas resisting shape deformation. In brief, the phenomenon occurs because, in contrast to normal lung, the injured lung does not exhibit fluid like behavior. Even if the tidal volume of the ventilator is limited to less than 6ml/kg, there will be excessive stretching of the lungs in some areas due to swinging breathing. As a result, EIT can be used to monitor in real time the increasing regional inhomogeneity and deduplication of the lungs.In addition, it is different from the instantaneous examination such as chest film and bedside bronchoscopy, which is more conducive to the whole-process monitoring and evaluation of patients.\u003c/p\u003e \u003cp\u003eIt has been proved that the monitoring results of EIT perfusion imaging also have a good correlation with the anatomical structure and CT scan results corresponding to blood flow changes. Zhang et al. found that during VV-ECMO, the ECMO blood flow rate, closely related to recirculation fraction, which will have a stronger influence on the distribution of bolus saline across the regional lung, thus affecting the accuracy of lung perfusion assessment using hypertonic saline bolus-based EIT[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Therefore, EIT has shown certain advantages and potential in the evaluation of perfusion.\u003c/p\u003e \u003cp\u003eThis work has some limitations. First, our study was carried out in a single center, and a small number of patients were included. Second, changes in the position of the electrode band can significantly affect the results of the EIT, which increases the uncertainty when analyzing the data. Third, EIT results do not fully explain the anatomical changes that lead to ventilation and perfusion, and small pulmonary changes may not cause significant changes in local perfusion or ventilation. The role of EIT in monitoring lung function after lung transplantation needs to be further confirmed by multi-center studies with large sample size.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eOur study shows that it is safe and reasonable for patients after lung transplantation to use EIT to monitor lung ventilation and perfusion. The use of relevant EIT parameters (such as GI and LHI) can supplement the relevant lung conditions and understand the physiological trends of individual patients, which may help clinicians make more accurate clinical decisions in the future.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eECMO \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Extracorporeal membrane oxygenation\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSBT \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Spontaneous breathing trials\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eEIT \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Electrical impedance tomography\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eICU \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Intensive care unit\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eROI \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Region of interest\u003c/p\u003e\n\u003cp\u003eCOV \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Center of ventilation\u003c/p\u003e\n\u003cp\u003eGI \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Global inhomogeneity index\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eLHI \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Lung heterogeneity index\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eRVD \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Regional ventilation delay\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e△(CW-CL) \u0026nbsp; \u0026nbsp; \u0026nbsp;The change in compliance change percentage variation\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e△EELI/VT \u0026nbsp; \u0026nbsp; \u0026nbsp; End-expiratory lung impedance and tidal volume ratio\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePMV \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Prolonged mechanical ventilation\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors contributed to this case report. All provided input and critique on the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis case report was financially supported by no funding.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe Institutional Ethics Committees of Wuxi People\u0026rsquo;s Hospital affiliated to Nanjing Medical University approved this study. Informed consents in written form were obtained from the patients or their next of kin in written.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWritten informed consent was obtained from the patients for publication of this article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eThille, A.W., et al., Spontaneous-Breathing Trials with Pressure-Support Ventilation or a T-Piece. N Engl J Med, 2022. 387(20): p. 1843-1854.\u003c/li\u003e\n\u003cli\u003eBlankman, P., et al., Detection of \u0026apos;best\u0026apos; positive end-expiratory pressure derived from electrical impedance tomography parameters during a decremental positive end-expiratory pressure trial. Crit Care, 2014. 18(3): p. R95.\u003c/li\u003e\n\u003cli\u003eSpadaro, S., et al., Variation of poorly ventilated lung units (silent spaces) measured by electrical impedance tomography to dynamically assess recruitment. Crit Care, 2018. 22(1): p. 26.\u003c/li\u003e\n\u003cli\u003eBickenbach, J., et al., Electrical impedance tomography for predicting failure of spontaneous breathing trials in patients with prolonged weaning. Crit Care, 2017. 21(1): p. 177.\u003c/li\u003e\n\u003cli\u003eWrigge, H., et al., Electrical impedance tomography compared with thoracic computed tomography during a slow inflation maneuver in experimental models of lung injury. Crit Care Med, 2008. 36(3): p. 903-9.\u003c/li\u003e\n\u003cli\u003eHoetzenecker, K., et al., Intraoperative extracorporeal membrane oxygenation and the possibility of postoperative prolongation improve survival in bilateral lung transplantation. J Thorac Cardiovasc Surg, 2018. 155(5): p. 2193-2206.e3.\u003c/li\u003e\n\u003cli\u003eEvans, L., et al., Surviving sepsis campaign: international guidelines for management of sepsis and septic shock 2021. Intensive Care Med, 2021. 47(11): p. 1181-1247.\u003c/li\u003e\n\u003cli\u003eSchwarz, S., et al., Ventilation parameters and early graft function in double lung transplantation. J Heart Lung Transplant, 2021. 40(1): p. 4-11.\u003c/li\u003e\n\u003cli\u003ePilcher, D.V., et al., High central venous pressure is associated with prolonged mechanical ventilation and increased mortality after lung transplantation. J Thorac Cardiovasc Surg, 2005. 129(4): p. 912-8.\u003c/li\u003e\n\u003cli\u003eGao, P., et al., Establishment of a risk prediction model for prolonged mechanical ventilation after lung transplantation: a retrospective cohort study. BMC Pulm Med, 2023. 23(1): p. 11.\u003c/li\u003e\n\u003cli\u003eZhao, Z., et al., PEEP titration guided by ventilation homogeneity: a feasibility study using electrical impedance tomography. Crit Care, 2010. 14(1): p. R8.\u003c/li\u003e\n\u003cli\u003eLi, J., et al., Electrical Impedance Tomography Predicts Weaning Success in Adult Patients With Delayed Upper Abdominal Surgery: A Single-Center Retrospective Study. Front Med (Lausanne), 2021. 8(2): p. 748493.\u003c/li\u003e\n\u003cli\u003eZhang, H., et al., Effects of different VV ECMO blood flow rates on lung perfusion assessment by hypertonic saline bolus-based electrical impedance tomography. Crit Care, 2024. 28(1): p. 274.\u003c/li\u003e\n\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":"Electrical impedance tomography, Lung transplantation, Prolonged mechanical ventilation","lastPublishedDoi":"10.21203/rs.3.rs-5737031/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5737031/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e Electrical impedance tomography (EIT) based on pulsatility method and the saline bolus injection method has become more mature in recent years. However, clinical studies about the use of EIT in patients after lung transplantation has not emerged. We used EIT to observe the changes of lung ventilation and perfusion after lung transplantation, and combined with blood gas analysis, lung ultrasound score (LUS), and other clinical indicators to evaluate the therapeutic effectiveness of lung transplantation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e Patients who received lung transplantation at the Lung Transplant Center of Wuxi People's Hospital affiliated to Nanjing Medical University from December 2023 to January 2024 were included in this retrospective review. Patients were divided into prolonged mechanical ventilation (PMV) group and control group according to whether invasive mechanical ventilation lasted more than 72 hours after surgery. General data, arterial blood gas results, ultrasonic LUS score were recorded. The lungs were divided into region of interest (ROI) 1 to 4. Ventilation and perfusion data of each region during extracorporeal membrane oxygenation (ECMO) combined mechanical ventilation (H1), during mechanical ventilation (H2), and post-extubation (H3) were also recorded.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e 1. Low/high-speed passband index (LHI) during H2 and H3 was significantly higher in control group than in PMV group, with statistical difference (P \u0026lt; 0.05). 2. Center of ventilation (COV) showed a downward trend in postoperative patients, while COV in control group was closer to the gravity-dependent area. 3. At each stage, LUS in PMV group was significantly higher than that in control group, with statistical significance (P \u0026lt; 0.05).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e It is safe and reasonable to use EIT to monitor pulmonary ventilation and perfusion after lung transplantation.The use of relevant EIT parameters (e.g. GI,LHI) can be supplemented with lung relevant information to understand individual patient physiological trends.\u003c/p\u003e","manuscriptTitle":"Changes Of Lung Ventilation And Perfusion After Lung Transplantation Based On Electrical Impedance Tomography","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-01-02 09:27:46","doi":"10.21203/rs.3.rs-5737031/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":"e636124d-981e-45ec-b12b-86a81836c7a3","owner":[],"postedDate":"January 2nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-01-23T10:38:57+00:00","versionOfRecord":[],"versionCreatedAt":"2025-01-02 09:27:46","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5737031","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5737031","identity":"rs-5737031","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}