Impact of arm position compared to tourniquet and general anesthesia on peripheral vein width in supine adult patients: A prospective, monocentric, cross-sectional study

Impact of arm position compared to tourniquet and general anesthesia on peripheral vein width in supine adult patients: A prospective, monocentric, cross-sectional study | 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 Impact of arm position compared to tourniquet and general anesthesia on peripheral vein width in supine adult patients: A prospective, monocentric, cross-sectional study Christian Berger, Philipp Brandhorst, Elena Asen, Sven Grallert, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4368889/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 22 Oct, 2024 Read the published version in BMC Anesthesiology → Version 1 posted 4 You are reading this latest preprint version Abstract Background IV access is a commonly performed procedure that is often taught based on tradition rather than evidence. The effect of arm retroflexion on vein width, either alone or in combination with a tourniquet or general anaesthesia (GA), remains unclear. In this case, the sonographically measured vein width is a surrogate parameter for the success of the puncture. Methods Prospective, cross-sectional study involving 57 patients scheduled for surgery in general anesthesia. We analyzed the impact of arm retroflexion, tourniquet, general anesthesia, and their combinations on the antebrachial veins in supine patients by ultrasound. Measurements were taken awake and during general anesthesia, each with and without the application of a tourniquet, and in three different arm positions (0°, 30°, and max° retroflexion) each. Data are presented as median and interquartile range [IQR]. Results Tourniquet application (AT) had the greatest single effect on Cubital vein outer diameter (CuV-OD) compared to the baseline value of all measures (3.9 mm [3.4–5.1]; 4.8 mm [4.1–5.7], P = 0.001, r = 0.515). This effect was surpassed by the combination of AT and GA (5.1 mm [4.6–6.6], P = 0.001, r = 0.889). In contrast, retroflexion alone did not result in an increase in the CuV–OD at either 30° (4.2 mm [3.7–5.1], p = 1.0, r = 0.12) or max° (4.2 mm [3.6–4.9], p = 0.72, r = 0.23). With GA and AT, no further enlargement was measurable by 30° (5.4 mm [4.6–6.6], p = 1.0, r = 0.15) or max° (5.4 mm [4.6–6.6], p = 1.0, r = 0.07) retroflexion compared to GA-AT-0° (5.1 mm [4.6–6.6], p = 1.0, r = 0.15). Conclusions This study provides evidence that retroflexion of the arm in supine patients, whether alone or in addition to a tourniquet or GA, does not have any additional effect on vein width as a surrogate parameter for successful IV success. It shows for the first time that general anesthesia effectively increase vein diameter. Trial registration DRKS00029603 ultrasound ultrasound guiding venous access patient safety vein size vein width Figures Figure 1 Figure 2 Figure 3 Figure 4 Background Peripheral intravenous (IV) access for rapid and safe administration of necessary medications is a fundamental medical procedure in clinical practice, especially in anesthesia as well as in emergencies. Delayed insertion due to multiple puncture attempts delays drug administration and can be painful and distressing for patients [ 1 ]. Multiple punctures are associated with complications like nerve damage, hematoma, and higher medical costs [ 2 ]. Therefore, measures increasing vein size should be applied for IV access, as a larger vein diameter is associated with a higher success rate of peripheral vein cannulation [ 3 – 5 ]. Applying a tourniquet for increasing venous filling by venous pooling, as well as tapping of veins, hand pumping, and application of heat, are known measures for increasing vein size [ 6 – 10 ]. The patient´s posture as well as lowering the arm below the heart´s level (gravidity-associated retroflexion) further seems to affect peripheral vein diameter but with inconsistent results [ 11 , 12 ]. IV access is mostly performed in the supine position in emergencies and during general anesthesia (GA). However, vein enlarging measures have been poorly studied under these conditions, and IV puncture is taught out of tradition and habit rather than evidence. Despite this lack of evidence, there are recommendations to position the arm below the heart regardless of patient´s posture [ 13 , 14 ]. It is currently unclear if this maneuver has a positive effect on vein size in a supine position. Nevertheless, it is performed in both, awake and anesthetized patients in clinical practice. Furthermore, retroflexion has not yet been evaluated in conjunction with other measures like GA or Tourniquet. Thus, the question of whether retroflexion in the shoulder joint of supine patients, either alone or in combination with GA or tourniquet, effectively increases IV puncture success remains unresolved. This is particularly crucial to address when additionally considering the potentially harmful effects of arm retroflexion under GA, such as stretching of the plexus may lead to relevant nerve damage [ 15 , 16 ]. Therefore, we conducted this prospective cross-sectional trial, analyzing the impact of upper limb retroflexion, both independently and in conjunction with tourniquet and GA on peripheral vein size, as a surrogate of IV puncture success. Methods Study design This study was a monocentric, prospective, cross-sectional trial at a tertiary hospital. Ethical approval was provided by the Ethikkommission der Charité - Universitätsmedizin Berlin, Germany (Ethical Committee N° EA4/102/22). All patients were checked for eligibility and gave their written informed consent. The trial was registered prior to patient enrollment at WHO International Clinical Trials Registry Platform and German Clinical Trial Register (DRKS00029603). The study protocol was carried out in accordance with the Declaration of Helsinki and this manuscript adheres to the applicable CONSORT guidelines. Patients and Setting The trial was performed from the 7th of July 2022 to the 13th of September 2022. Adult patients meeting ASA Classification I or II criteria scheduled for elective surgery in general anesthesia were enrolled in this study. Patients with disease or surgery of the upper extremities, shoulders, or thorax, and patients who met any of the following criteria were excluded: systemic vascular disease, recent thrombotic events, local vascular disease of the upper extremities, pre-existing cardiac disease associated with systolic or diastolic dysfunction, venous puncture on the limb to be measured within two weeks before examination, frequent venous punctures in the history or vasoactive concomitant medication. All procedures and measurements were performed in a tempered (19–21°C) anesthesia induction room of a central operating theatre area. Patients were placed in a supine position on an operating table with armrests padded underneath and fixable at respective degree settings in the shoulder joint during the whole procedure (Fig. 1 ). Measurements All measurements were performed on the cubital vein (CuV) and cephalic vein (CeV) on the nondominant arm using a high-frequency linear ultrasound probe (8–18 MHz, ultrasound device: Vivid iq, GE Healthcare, Chicago, IL, USA). Optimal measurement positions were identified in the fossa cubiti and at the middle of the forearm by ultrasound (Fig. 1 a). To ensure comparability, the position was marked and all subsequent measurements were taken at these markings. To avoid potential changes in vein geometry and size, the probe was placed gently on the skin to obtain an image without applying additional pressure. Each set of measurements included vein circumference (CI) and vein diameter in the out-of-plain probe position (OD) as well as vein diameter in the in-plain probe position (ID) to ensure accurate 2D measurements. All diameters were measured from anterior to posterior (AP) (Supplemental Fig. 1). All measurements were performed under the following patients’ conditions in consecutive order: 1) patient awake without tourniquet (awake-NT), 2) patient awake with tourniquet (awake-AT), 3) patient in GA without tourniquet (GA-NT), and 4) patient in GA with tourniquet (GA-AT). Within each condition, different levels of retroflexion (0°, 30°, and max°; Fig. 1 a-c) were applied in a randomized order. The patients waited in their respective positions for 60 seconds before the corresponding measurement was taken. After each measurement, patients rested in a supine position without a tourniquet and in 0° arm retroflexion for 2 minutes to ensure consistency in the starting position for each subsequent condition and arm position during measurement. The maximum possible retroflexion (max°) was determined in advance by slowly rotating the patient´s outstretched arm passively backward from the horizontal axis. As soon as the maximum possible retroflexion was reached or the patient indicated paresthesia or pain, the arm was slightly returned from retroflexion until there was no more discomfort. The thus determined degree of retroflexion [°] corresponded to the max° position for each patient. A tourniquet was applied using a 13.5 cm wide blood pressure cuff, placing it 2–3 cm above the cubital fossa and inflating it to 60 mmHg. Apart from the study-related procedures described above, no further measures were taken on the nondominant arm throughout the whole study period. Monitoring for anesthesia and IV access were established in the dominant arm before the study measurement. Peripheral oxygen saturation (SpO2) as well as heart rate were measured continuously. Blood pressure was measured initially before awake measurements and with the beginning of GA induction in 2.5-minute intervals on the dominant arm. Induction and maintenance of general anesthesia were performed according to institutional standard operating procedures (SOP). Statistics For analyzing measures to maximize vein size within a study cohort, a sample size calculation was performed in advance with a two-sided significance level of 5% and a power of 80%. Based on the previously reported effects of tourniquet application which range from 0.14–0.87 mm, with a maximum standard deviation of 1.3 mm, a mean change of 0.505 mm in vein diameter was assumed [ 12 ]. The calculation of the sample size yielded 54 patients for our study. To account for a potential dropout rate of 10%, the study was planned with a final total of 60 patients. Data processing and analysis were performed using IBM SPSS Statistics (version 25; IBM, Armonk, NY, USA). Data are presented as median (Interquartile range [IQR]). Differences between measurements were evaluated using a paired Friedman test with Bonferroni-correction for multiple comparisons. Significance was set at P < 0.05, also for Bonferroni-correction after mathematical adjustment was applied. The effect size for non-parametric testing was estimated using a z-statistic by calculating correlation coefficient r , with > 0.1 representing a small, > 0.3 a medium, and > 0.5 a large strength of association, according to the recommendations of Cohen [ 17 ]. To analyze the accuracy of the measurements, the intra-class correlation coefficient was calculated between in-plane and out-of-plane measurements. Patient demographics and hemodynamic/anesthesia data were reported as qualitative data and percentage or median [IQR], as applicable. Demographic as well as hemodynamic data and ventilation pressure settings were reported for transparency of the study cohort. No further statistical analyses were performed on this data. Only patients with complete data sets were included in the final data analyses. Results For the final analysis, 57 patients with complete data sets were included (Fig. 2). Patients´ characteristics are presented in Tab. 1. Hemodynamic data before and after induction of general anesthesia, as well as ventilator settings, were within normal range with a peak respiratory pressure of 15 [14-17] and a positive end-expiratory pressure of 5 [5-6]. The detailed data is provided in Supplemental Tab. 1. After awake measurements, GA was induced with propofol in all cases and supplemented with sufentanil/fentanyl in 32 (56%) or remifentanil in 25 (44%) cases. Maintenance of GA was performed with propofol in 37 (65%) and sevoflurane in 20 (35%) cases. 100 ml [50-230] of balanced isotone electrolyte solution was administered from induction of general anesthesia up to final measurements. Table 1 Patient characteristics Variables Total study sample (n=57) Age, years (median [IQR]) 40 [27-51] BMI, kg/m 2 (median [IQR]) 24.2 [22.2-26.9] Sex (female), n (%) 30 (53%) Right handed, n (%) 55 (97%) max° retroflexion, degree (median [IQR]) 75 [65-90] Abbreviations: BMI, Body mass index; IQR, Interquartile range; max° retroflexion, Maximum retroflexion in the shoulder joint Effect of retroflexion, GA and tourniquet A retroflexion of 30° or max° retroflexion in the shoulder joint was not associated with an increase in the CuV out-of-plane diameter compared to 0° within all conditions (Fig. 3, Tab. 2). CeV out-of-plane diameters did not show any effect of retroflexion, except for max° retroflexion compared to 0° in GA-NT (Fig. 4, Tab. 2). The application of a tourniquet resulted in a significant increase in the out-of-plane diameter of both CuV and CeV, with a greater effect size observed when used in combination with GA (Fig. 3-4). Application of GA alone, without a tourniquet, had a significant but reduced effect on CuV out-of-plane diameter compared to tourniquet application (Tab. 2). The intra-class correlation coefficient for CuV-awake OD and ID measurements was found to be 0.952 [0.919-0.972], indicating excellent reliability. Similarly, the CeV-awake OD and ID comparison revealed a coefficient of 0.840 [0.728- 0.905], indicating good reliability of the measurement results. Analyzation of CuV-CI and CeV-CI measurements revealed comparable results for retroflexion, Tourniquet, and GA (Supplemental Tab. 2-3, Supplemental Fig. 2-3). Discussion Our findings indicate that using a tourniquet and/or general anesthesia can effectively increase peripheral vein width. However, retroflexion of 30° or max° does not have any effect on vein width in supine patients. Previous studies have not thoroughly analyzed the impact of upper limb retroflexion with tourniquet application and its effect on vein width while in the supine position. Additionally, this is the first study to include patients in both awake and anesthetized states in its analysis. Only one earlier work by Cappelletti et al showed an increase in the diameter and area of peripheral cephalic and basilic veins in healthy, awake subjects in the supine position with the arm dangling at a 90° angle compared with 0° [18]. This contrasts sharply with our findings, possibly due to varying study conditions. First, our maximum position was less retroflexed (65-90°) compared with a dangling arm. Cappelletti et al. analyzed solely awake patients, in consideration of the potentially increased risk of plexus affection, especially in anesthetized patients, we avoided a dangling arm [15]. This should be considered in particular, as our awake evaluation of possible max retroflexion revealed, that 90° retroflexion cannot be achieved without paresthesia by most patients. Additionally, our work has shown a strong effect of the tourniquet. Therefore, it seems unlikely that gravity would have resulted in a significantly different effect for an arm bent backward 75° compared to an arm dangling 90°. Second, the measurements were performed in a more proximal position compared to our CeV measurements, resulting in different baseline vein widths. An evaluation by Yamagami et al. showed a larger baseline diameter than our CeV results at different measurement sites [11]. Thus, different heights at the upper limb for measurement and lower consistency of the specific measurement point, compared to our setting, may further explain differences in baseline widths and results [8, 19]. Furthermore, heat affects vein width, as peripheral vein width may also be affected by different room temperatures. This is reflected by larger baseline results in studies with slightly higher OR temps of 22-24°C, compared to our setting [20, 21]. Besides room temperature, local warming or tapping are other, previously reported measures that can influence vein size [6, 8, 20, 22]. It is uncertain whether these measures would affect our results for retroflexion. However, we avoided them to ensure the comparability of the measures evaluated. Our in-plane measurements agree with the out-of-plane measurements and can thus be considered as a validation of our measurement procedures (Supplemental Fig.2-3). This good correlation between the different measurement approaches indicates that differences in skin pressure with the probe, which could lead to possible vein deformation, were effectively avoided. In contrast to many previous works that analyzed the effects on vein width only in healthy volunteers, our study is the first to examine patients before and after induction of anesthesia [8, 10-12, 18-20, 22]. GA, and especially propofol, is known to decrease peripheral vascular resistance after induction [23]. For this reason, in a clinical setting, often a small IV is first placed followed by a larger IV after anesthesia induction. Our findings confirm this effect of GA on peripheral vein widths. Additionally, gravidity-associated retroflexion revealed no further relevant enlargement, particularly in anesthetized patients, even when applying a tourniquet. In contrast to healthy volunteers, all our patients were fasted before surgery, which may affect venous filling, especially since fasting has been discussed as a cause of difficult venipuncture [24, 25]. Previous research revealed controversial results regarding venous filling and reduced fluid intake during fasting. One study showed an increase in the cross-sectional diameter of the vena cava inferior after oral hydration in fasted patients [26]. Sharp et al demonstrated a reduction in forearm vein diameter after rehydration in fasting patients and discussed sympathetic nervous system activation as a possible cause [20]. Given these published controversial results, we administered fluids only at induction of general anesthesia and mostly in a "mild" form of less than 2 ml/kg body weight. Positive pressure ventilation can also act like a Valsalva maneuver and thus affect vein width [27]. In our study, the respiratory settings were within ranges considered normal, without particularly increased respiratory pressures, and were not altered during measurements for individual patients. We chose to evaluate patients in the supine position because it is the usual position for IV access before general anesthesia as well as in pre- and intrahospital emergencies [5, 28]. It has also been demonstrated that the size of the veins appears to be larger in the supine position than in the seated position [11]. Furthermore, all measurements in our work were performed within a short period with comparable baseline conditions, which underlines the pronounced effect of tourniquet application. Previous results showed the use of a blood pressure cuff had the greatest effect on increasing vein size and decreasing vein compressibility compared to other tourniquet techniques [29]. Sasaki et al. demonstrated an optimal effect of a blood pressure cuff on peripheral vein size enlargement when the cuff was inflated to a pressure of 60mmHg and applied for 30-60 seconds. After this time, there was no further increase in vein size [10]. According to these previous findings, our patients remained in each condition for 60 seconds before measurements were performed and the strong effect of tourniquet application was confirmed in our work. Limitations of the study It is known that vein width is influenced by gender [30], which was not explicitly analyzed in this work. Nevertheless, male and female participants were equally distributed in this work. For reasons of patient comfort as well as to avoid impairment of vein width by multiple punctures, cannula insertion at the measured extremity was omitted in all cases. IV puncture success was not measured and can only be estimated by vein width [3, 4]. Conclusion The application of a tourniquet had the greatest effect on the dilation of peripheral veins in supine patients, especially in anesthetized conditions. Additionally, our findings showed a strong increase in vein widths after GA induction. In contrast, arm retroflexion, alone or in combination, showed no further effects on vein width. Abbreviations AP anterior to posterior AT Tourniquet application BMI Body mass index CeV Cephalic vein CI Circumference CuV Cubital vein GA general anesthesia ID Vein diameter in-plane IQR Interquartile range IV Intravenous NT without Tourniquet OD Vein diameter out-of-plane SOP standard operating procedure SpO2 Peripheral oxygen saturation Declarations Ethics approval and consent to participate Ethical approval was provided by the Ethikkommission der Charité - Universitätsmedizin Berlin, Germany (Ethical Committee N° EA4/102/22). All patients were checked for eligibility and gave their written informed consent. The trial was registered prior to patient enrollment at WHO International Clinical Trials Registry Platform and German Clinical Trial Register (DRKS00029603). The study protocol was carried out in accordance with the Declaration of Helsinki and this manuscript adheres to the applicable CONSORT guidelines. Availability of data and materials The datasets used and analyzed during the current study are available from the corresponding author on reasonable request. Consent for publication Not applicable. Competing interests The authors certify that there is no conflict of interest with any financial organization regarding the material discussed in the manuscript. Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Financial support and sponsorship: This work was supported by the Department of Anesthesiology and Operative Intensive Care Medicine, Campus Benjamin Franklin, Charité – Universitätsmedizin Berlin, Germany. Authors' contributions CRediT authorship contribution statement Christian Berger: Conceptualization; Methodology; Formal analysis; Investigation; Data Curation; Validation; Visualization; Writing - Original Draft; Project administration Philipp Brandhorst: Conceptualization; Investigation; Visualization; Writing - Review & Editing Elena Asen: Investigation; Data Curation; Writing - Review & Editing Sven Grallert: Investigation; Writing - Review & Editing Sascha Treskatsch: Conceptualization; Methodology; Resources; Writing - Review & Editing; Supervision Moritz Weigeldt: Conceptualization; Methodology; Formal analysis; Investigation; Data Curation; Validation; Writing - Original Draft; Project administration All authors read and approved the final version of the manuscript Congresses Parts of this paper was presented as poster at the German Anesthesiology Congress (DAC 2023) that was held in Düsseldorf on 27. - 29. April 2023. References Sebbane M, Claret P-G, Lefebvre S, Mercier G, Rubenovitch J, Jreige R, et al. Predicting Peripheral Venous Access Difficulty in the Emergency Department Using Body Mass Index and a Clinical Evaluation of Venous Accessibility. J Emerg Med. 2013;44(2):299–305. Tanabe H, Kawasaki M, Ueda T, Yokota T, Zushi Y, Murayama R, et al. A short bevel needle with a very thin tip improves vein puncture performance of peripheral intravenous catheters: An experimental study. J Vasc Access. 2020;21(6):969–76. Panebianco NL, Fredette JM, Szyld D, Sagalyn EB, Pines JM, Dean AJ. What you see (sonographically) is what you get: vein and patient characteristics associated with successful ultrasound-guided peripheral intravenous placement in patients with difficult access. Acad Emerg Med. 2009;16(12):1298–303. Witting MD, Schenkel SM, Lawner BJ, Euerle BD. Effects of vein width and depth on ultrasound-guided peripheral intravenous success rates. J Emerg Med. 2010;39(1):70–5. Loon FHJv, Puijn LAPM, Houterman S, Bouwman ARA. Development of the A-DIVA Scale: A Clinical Predictive Scale to Identify Difficult Intravenous Access in Adult Patients Based on Clinical Observations. Medicine. 2016;95(16):e3428. Ichimura M, Sasaki S, Ogino T. Tapping enhances vasodilation for venipuncture even in individuals with veins that are relatively difficult to palpate. Clin Anat. 2020;33(3):440–5. Yamagami Y, Tomita K, Tsujimoto T, Inoue T. Tourniquet application after local forearm warming to improve venodilation for peripheral intravenous cannulation in young and middle-aged adults: A single-blind prospective randomized controlled trial. Int J Nurs Stud. 2017;72:1–7. Ichimura M, Sasaki S, Mori M, Ogino T. Tapping but not massage enhances vasodilation and improves venous palpation of cutaneous veins. Acta Med Okayama. 2015;69(2):79–85. Simons P, Coleridge Smith P, Lees WR, McGrouther DA. Venous pumps of the hand. Their clinical importance. J Hand Surg Br. 1996;21(5):595–9. Sasaki S, Murakami N, Matsumura Y, Ichimura M, Mori M. Relationship between tourniquet pressure and a cross-section area of superficial vein of forearm. Acta Med Okayama. 2012;66(1):67–71. Yamagami Y, Inoue T. Patient Position Affects Venodilation for Peripheral Intravenous Cannulation. Biol Res Nurs. 2020;22(2):226–33. Mahler SA, Massey G, Meskill L, Wang H, Arnold TC. Can we make the basilic vein larger? maneuvers to facilitate ultrasound guided peripheral intravenous access: a prospective cross-sectional study. Int J Emerg Med. 2011;4:53. Mbamalu D, Banerjee A. Methods of obtaining peripheral venous access in difficult situations. Postgrad Med J. 1999;75(886):459. Peripheral TRIMBLET. I.V. starts: Vein preparation tips. Nursing2021. 2003;33(7):17. Cheney Frederick W, Domino Karen B, Caplan Robert A, Posner Karen L. Nerve Injury Associated with Anesthesia: A Closed Claims Analysis. Anesthesiology. 1999;90(4):1062–9. Zhang J, Moore AE, Stringer MD. Iatrogenic upper limb nerve injuries: a systematic review. ANZ J Surg. 2011;81(4):227–36. Fritz CO, Morris PE, Richler JJ. Effect size estimates: current use, calculations, and interpretation. J Exp Psychol Gen. 2012;141(1):2–18. Cappelletti S, Caimi A, Caldiroli A, Baroni I, Votta E, Riboldi SA, et al. Non-invasive estimation of vascular compliance and distensibility in the arm vessels: a novel ultrasound-based protocol. Quant Imaging Med Surg. 2022;12(7):3515–27. Ichimura M, Sasaki S, Ogino T. Tapping enhances vasodilation for venipuncture even in individuals with veins that are relatively difficult to palpate. Clin Anat. 2020;33(3):440–5. Sharp R, Childs J, Bulmer AC, Esterman A. The effect of oral hydration and localised heat on peripheral vein diameter and depth: A randomised controlled trial. Appl Nurs Res. 2018;42:83–8. van Bemmelen PS, Kelly P, Blebea J. Improvement in the visualization of superficial arm veins being evaluated for access and bypass. J Vasc Surg. 2005;42(5):957–62. Yamagami Y, Tsujimoto T, Inoue T. How long should local warming for venodilation be used for peripheral intravenous cannulation? A prospective observational study. Int J Nurs Stud. 2018;79:52–7. Boer F, Ros P, Bovill JG, Van Brummelen P, Van Der Krogt J, EFFECT OF PROPOFOL ON PERIPHERAL VASCULAR RESISTANCE DURING CARDIOPULMONARY BYPASS. Br J Anaesth. 1990;65(2):184–9. Costantino TG, Kirtz JF, Satz WA. Ultrasound-guided peripheral venous access vs. the external jugular vein as the initial approach to the patient with difficult vascular access. J Emerg Med. 2010;39(4):462–7. Schoenfeld E, Boniface K, Shokoohi H, editors. ED technicians can successfully place ultrasound-guided intravenous catheters in patients with poor vascular access. Am J Emerg Med. 2011;29(5):496–501. Diaconu CI, Fox RJ, Grattan A, Rae-Grant A, Lu M, Gornik HL, Kim ES. Hydration status substantially affects chronic cerebrospinal venous insufficiency assessments. Neurol Clin Pract. 2013;3(5):386–91. Villa G, Chelazzi C, Giua R, Lavacchini L, Tofani L, Zagli G, et al. The Valsalva manoeuvre versus tourniquet for venipuncture. J Vasc Access. 2018;19(5):436–40. Paterson RS, Schults JA, Slaughter E, Cooke M, Ullman A, Kleidon TM, et al. Review article: Peripheral intravenous catheter insertion in adult patients with difficult intravenous access: A systematic review of assessment instruments, clinical practice guidelines and escalation pathways. Emerg Med Australas. 2022;34(6):862–70. Kule A, Hang B, Bahl A. Preventing the collapse of a peripheral vein during cannulation: an evaluation of various tourniquet techniques on vein compressibility. J Emerg Med. 2014;46(5):659–66. Kröger K, Ose C, Rudofsky G, Roesener J, Weiland D, Hirche H. Peripheral veins: influence of gender, body mass index, age and varicose veins on cross-sectional area. Vasc Med. 2003;8(4):249–55. Additional Declarations No competing interests reported. Supplementary Files CUVEsuppltable1BMCA.docx CUVEsuppltable23BMCA.docx CUVEsupplementalFigures1BMCA.jpg CUVEsupplementalFigures2BMCA.png CUVEsupplementalFigures3BMCA.png Cite Share Download PDF Status: Published Journal Publication published 22 Oct, 2024 Read the published version in BMC Anesthesiology → Version 1 posted Editorial decision: Revision requested 17 May, 2024 Submission checks completed at journal 15 May, 2024 Editor assigned by journal 15 May, 2024 First submitted to journal 04 May, 2024 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-4368889","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":303614777,"identity":"61863546-2880-40d3-9bb1-fcf3f90a296c","order_by":0,"name":"Christian Berger","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABKElEQVRIie2QMUvDQBTHLxTscvbWy9J+hRcOUgtVv0rKQaZgO3bSy1KX1rngl8gkuF3IkCXdKzgoQmeLSyIBvcYqHS7BUfB+cMfj3f34vzuEDIa/CEVIVjvCXw1SFbArvQbFO1BsUSnQqOzP9grIqqhXyO3iOS7yk14fHccv0/fhmKWr+G06KbuozaU25DGFBHvUuRcd7qxu/MFddsHtDIAhvNHGAPVRot5iRRK7djhPwF1jsAXASNAA6pQ49+i5UvpFOP8AtsSsUMqVoOPXOkWqwUa7FEvkEoCqOKV4iAb6D1urwbBPeZR0uB0KDjQL3IEA5szwRjsYWfqtbT68PI3SRbwV5RmQ64w9iLLbI23+pI35oaWWNTtoHDXf/6b83TWDwWD4X3wCxzVeChMgFvEAAAAASUVORK5CYII=","orcid":"","institution":"Charité - Universitätsmedizin Berlin, Humboldt Universität zu Berlin","correspondingAuthor":true,"prefix":"","firstName":"Christian","middleName":"","lastName":"Berger","suffix":""},{"id":303614778,"identity":"0fb01a0f-8870-4118-8287-03ceaffe7a9e","order_by":1,"name":"Philipp Brandhorst","email":"","orcid":"","institution":"Charité - Universitätsmedizin Berlin, Humboldt Universität zu Berlin","correspondingAuthor":false,"prefix":"","firstName":"Philipp","middleName":"","lastName":"Brandhorst","suffix":""},{"id":303614780,"identity":"5e6a7286-0f37-4408-8bf7-a5ba1327aeab","order_by":2,"name":"Elena Asen","email":"","orcid":"","institution":"Charité - Universitätsmedizin Berlin, Humboldt Universität zu Berlin","correspondingAuthor":false,"prefix":"","firstName":"Elena","middleName":"","lastName":"Asen","suffix":""},{"id":303614781,"identity":"5aa5c6b2-c10b-4db4-ac39-b572e18ff398","order_by":3,"name":"Sven Grallert","email":"","orcid":"","institution":"Helios Hospital Emil von Behring","correspondingAuthor":false,"prefix":"","firstName":"Sven","middleName":"","lastName":"Grallert","suffix":""},{"id":303614783,"identity":"f9daaf2c-4081-46de-9300-db011464ed26","order_by":4,"name":"Sascha Treskatsch","email":"","orcid":"","institution":"Charité - Universitätsmedizin Berlin, Humboldt Universität zu Berlin","correspondingAuthor":false,"prefix":"","firstName":"Sascha","middleName":"","lastName":"Treskatsch","suffix":""},{"id":303614784,"identity":"afb1378c-20aa-4335-af62-58b5d1fda2ec","order_by":5,"name":"Moritz Weigeldt","email":"","orcid":"","institution":"Charité - Universitätsmedizin Berlin, Humboldt Universität zu Berlin","correspondingAuthor":false,"prefix":"","firstName":"Moritz","middleName":"","lastName":"Weigeldt","suffix":""}],"badges":[],"createdAt":"2024-05-04 14:47:35","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4368889/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4368889/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12871-024-02765-6","type":"published","date":"2024-10-22T15:57:15+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":57445692,"identity":"69085568-d9ba-44a2-aed1-d791fea14e82","added_by":"auto","created_at":"2024-05-30 19:22:50","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":408693,"visible":true,"origin":"","legend":"\u003cp\u003eFigure showing the positioning of the arm in relation to the shoulder joint.\u003c/p\u003e\n\u003cp\u003ea, 0° position, 1 shows the measuring point of the cubital vein, and 2 is the measuring point of the cephalic vein. b, 30° retroflexion position. c, maximum retroflexion position (median 75° [Interquartile range 65-90]).\u003c/p\u003e","description":"","filename":"CUVEFig1BMCA.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4368889/v1/c6c4dd629d58313c9f7f4e0f.jpg"},{"id":57446085,"identity":"c61e039d-9aa0-4175-b19e-bbc3c76d36ce","added_by":"auto","created_at":"2024-05-30 19:30:50","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":69614,"visible":true,"origin":"","legend":"\u003cp\u003eConsort Flowchart.\u003c/p\u003e","description":"","filename":"Fig2ConsortFlowchartBMC.png","url":"https://assets-eu.researchsquare.com/files/rs-4368889/v1/1cd751e26eed6135add8aede.png"},{"id":57445690,"identity":"da8ddd94-8006-433f-a805-1433d6926cc3","added_by":"auto","created_at":"2024-05-30 19:22:50","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":631999,"visible":true,"origin":"","legend":"\u003cp\u003eBoxplots showing Cubital Vein out-of-plane measured diameter (CuV-OD) in millimeter [mm] for 0°-30°-max° retroflexion, eeach measured in awake without tourniquet applied (awake-NT), awake with applied tourniquet (awake-AT), general anesthesia without tourniquet applied (GA-NT) and general anesthesia with applied tourniquet (GA-AT).\u003c/p\u003e","description":"","filename":"CUVEFIG3BMCA.png","url":"https://assets-eu.researchsquare.com/files/rs-4368889/v1/767c05937f832b017a16d010.png"},{"id":57446086,"identity":"36a81deb-f710-4c59-864f-270c089d9ae0","added_by":"auto","created_at":"2024-05-30 19:30:50","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":600868,"visible":true,"origin":"","legend":"\u003cp\u003eBoxplots showing the Cephalic Vein out-of-plane measured diameter (CeV-OD) in millimeter [mm] for 0°-30°-max° retroflexionm, each measured in awake with no tourniquet applied (awake-NT), awake with applied tourniquet (awake-AT), general anesthesia with no tourniquet applied (GA-NT) and general anesthesia with applied tourniquet (GA-AT).\u003c/p\u003e","description":"","filename":"CUVEFIG4BMCA.png","url":"https://assets-eu.researchsquare.com/files/rs-4368889/v1/ae0594dee4ead3e88e4df7bf.png"},{"id":67682051,"identity":"3a5f871b-bb88-4ff5-8c89-7103d4d1e330","added_by":"auto","created_at":"2024-10-28 16:12:55","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2440597,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4368889/v1/a1cc2c46-0200-456a-b87f-6c746ce4eef2.pdf"},{"id":57445694,"identity":"807c0cd1-a0b5-44b8-a4c0-51097c723bf9","added_by":"auto","created_at":"2024-05-30 19:22:50","extension":"docx","order_by":7,"title":"","display":"","copyAsset":false,"role":"supplement","size":15631,"visible":true,"origin":"","legend":"","description":"","filename":"CUVEsuppltable1BMCA.docx","url":"https://assets-eu.researchsquare.com/files/rs-4368889/v1/ddc5699c8f7c9cfdee8b2bbf.docx"},{"id":57446087,"identity":"5e31d5f2-c17d-4e2f-afd7-5e9342f2a233","added_by":"auto","created_at":"2024-05-30 19:30:50","extension":"docx","order_by":8,"title":"","display":"","copyAsset":false,"role":"supplement","size":17666,"visible":true,"origin":"","legend":"","description":"","filename":"CUVEsuppltable23BMCA.docx","url":"https://assets-eu.researchsquare.com/files/rs-4368889/v1/918ddaa5e9f00e31cb134e62.docx"},{"id":57445696,"identity":"ea1f75c0-fd73-4117-af71-14d837f99137","added_by":"auto","created_at":"2024-05-30 19:22:50","extension":"jpg","order_by":9,"title":"","display":"","copyAsset":false,"role":"supplement","size":620135,"visible":true,"origin":"","legend":"","description":"","filename":"CUVEsupplementalFigures1BMCA.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4368889/v1/338740d2a0ed92c6154aca9f.jpg"},{"id":57445697,"identity":"e0304c51-8858-4138-9eb1-342ea7422389","added_by":"auto","created_at":"2024-05-30 19:22:50","extension":"png","order_by":10,"title":"","display":"","copyAsset":false,"role":"supplement","size":789513,"visible":true,"origin":"","legend":"","description":"","filename":"CUVEsupplementalFigures2BMCA.png","url":"https://assets-eu.researchsquare.com/files/rs-4368889/v1/91e48b2450fafea57370df9c.png"},{"id":57445698,"identity":"b29aa7f7-fa72-44f1-b5b8-57120adf08a3","added_by":"auto","created_at":"2024-05-30 19:22:50","extension":"png","order_by":11,"title":"","display":"","copyAsset":false,"role":"supplement","size":745603,"visible":true,"origin":"","legend":"","description":"","filename":"CUVEsupplementalFigures3BMCA.png","url":"https://assets-eu.researchsquare.com/files/rs-4368889/v1/b3ebc67ef923d41413d9d2d0.png"}],"financialInterests":"No competing interests reported.","formattedTitle":"Impact of arm position compared to tourniquet and general anesthesia on peripheral vein width in supine adult patients: A prospective, monocentric, cross-sectional study","fulltext":[{"header":"Background","content":"\u003cp\u003ePeripheral intravenous (IV) access for rapid and safe administration of necessary medications is a fundamental medical procedure in clinical practice, especially in anesthesia as well as in emergencies. Delayed insertion due to multiple puncture attempts delays drug administration and can be painful and distressing for patients [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Multiple punctures are associated with complications like nerve damage, hematoma, and higher medical costs [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Therefore, measures increasing vein size should be applied for IV access, as a larger vein diameter is associated with a higher success rate of peripheral vein cannulation [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eApplying a tourniquet for increasing venous filling by venous pooling, as well as tapping of veins, hand pumping, and application of heat, are known measures for increasing vein size [\u003cspan additionalcitationids=\"CR7 CR8 CR9\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. The patient\u0026acute;s posture as well as lowering the arm below the heart\u0026acute;s level (gravidity-associated retroflexion) further seems to affect peripheral vein diameter but with inconsistent results [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. IV access is mostly performed in the supine position in emergencies and during general anesthesia (GA). However, vein enlarging measures have been poorly studied under these conditions, and IV puncture is taught out of tradition and habit rather than evidence. Despite this lack of evidence, there are recommendations to position the arm below the heart regardless of patient\u0026acute;s posture [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. It is currently unclear if this maneuver has a positive effect on vein size in a supine position. Nevertheless, it is performed in both, awake and anesthetized patients in clinical practice. Furthermore, retroflexion has not yet been evaluated in conjunction with other measures like GA or Tourniquet. Thus, the question of whether retroflexion in the shoulder joint of supine patients, either alone or in combination with GA or tourniquet, effectively increases IV puncture success remains unresolved. This is particularly crucial to address when additionally considering the potentially harmful effects of arm retroflexion under GA, such as stretching of the plexus may lead to relevant nerve damage [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Therefore, we conducted this prospective cross-sectional trial, analyzing the impact of upper limb retroflexion, both independently and in conjunction with tourniquet and GA on peripheral vein size, as a surrogate of IV puncture success.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy design\u003c/h2\u003e \u003cp\u003eThis study was a monocentric, prospective, cross-sectional trial at a tertiary hospital. Ethical approval was provided by the Ethikkommission der Charit\u0026eacute; - Universit\u0026auml;tsmedizin Berlin, Germany (Ethical Committee N\u0026deg; EA4/102/22). All patients were checked for eligibility and gave their written informed consent. The trial was registered prior to patient enrollment at WHO International Clinical Trials Registry Platform and German Clinical Trial Register (DRKS00029603). The study protocol was carried out in accordance with the Declaration of Helsinki and this manuscript adheres to the applicable CONSORT guidelines.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003ePatients and Setting\u003c/h2\u003e \u003cp\u003eThe trial was performed from the 7th of July 2022 to the 13th of September 2022. Adult patients meeting ASA Classification I or II criteria scheduled for elective surgery in general anesthesia were enrolled in this study. Patients with disease or surgery of the upper extremities, shoulders, or thorax, and patients who met any of the following criteria were excluded: systemic vascular disease, recent thrombotic events, local vascular disease of the upper extremities, pre-existing cardiac disease associated with systolic or diastolic dysfunction, venous puncture on the limb to be measured within two weeks before examination, frequent venous punctures in the history or vasoactive concomitant medication.\u003c/p\u003e \u003cp\u003eAll procedures and measurements were performed in a tempered (19\u0026ndash;21\u0026deg;C) anesthesia induction room of a central operating theatre area. Patients were placed in a supine position on an operating table with armrests padded underneath and fixable at respective degree settings in the shoulder joint during the whole procedure (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eMeasurements\u003c/h2\u003e \u003cp\u003eAll measurements were performed on the cubital vein (CuV) and cephalic vein (CeV) on the nondominant arm using a high-frequency linear ultrasound probe (8\u0026ndash;18 MHz, ultrasound device: Vivid iq, GE Healthcare, Chicago, IL, USA). Optimal measurement positions were identified in the fossa cubiti and at the middle of the forearm by ultrasound (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea). To ensure comparability, the position was marked and all subsequent measurements were taken at these markings. To avoid potential changes in vein geometry and size, the probe was placed gently on the skin to obtain an image without applying additional pressure. Each set of measurements included vein circumference (CI) and vein diameter in the out-of-plain probe position (OD) as well as vein diameter in the in-plain probe position (ID) to ensure accurate 2D measurements. All diameters were measured from anterior to posterior (AP) (Supplemental Fig.\u0026nbsp;1).\u003c/p\u003e \u003cp\u003eAll measurements were performed under the following patients\u0026rsquo; conditions in consecutive order: 1) patient awake without tourniquet (awake-NT), 2) patient awake with tourniquet (awake-AT), 3) patient in GA without tourniquet (GA-NT), and 4) patient in GA with tourniquet (GA-AT). Within each condition, different levels of retroflexion (0\u0026deg;, 30\u0026deg;, and max\u0026deg;; Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea-c) were applied in a randomized order.\u003c/p\u003e \u003cp\u003eThe patients waited in their respective positions for 60 seconds before the corresponding measurement was taken. After each measurement, patients rested in a supine position without a tourniquet and in 0\u0026deg; arm retroflexion for 2 minutes to ensure consistency in the starting position for each subsequent condition and arm position during measurement.\u003c/p\u003e \u003cp\u003eThe maximum possible retroflexion (max\u0026deg;) was determined in advance by slowly rotating the patient\u0026acute;s outstretched arm passively backward from the horizontal axis. As soon as the maximum possible retroflexion was reached or the patient indicated paresthesia or pain, the arm was slightly returned from retroflexion until there was no more discomfort. The thus determined degree of retroflexion [\u0026deg;] corresponded to the max\u0026deg; position for each patient.\u003c/p\u003e \u003cp\u003eA tourniquet was applied using a 13.5 cm wide blood pressure cuff, placing it 2\u0026ndash;3 cm above the cubital fossa and inflating it to 60 mmHg.\u003c/p\u003e \u003cp\u003eApart from the study-related procedures described above, no further measures were taken on the nondominant arm throughout the whole study period. Monitoring for anesthesia and IV access were established in the dominant arm before the study measurement. Peripheral oxygen saturation (SpO2) as well as heart rate were measured continuously. Blood pressure was measured initially before awake measurements and with the beginning of GA induction in 2.5-minute intervals on the dominant arm. Induction and maintenance of general anesthesia were performed according to institutional standard operating procedures (SOP).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eStatistics\u003c/h2\u003e \u003cp\u003eFor analyzing measures to maximize vein size within a study cohort, a sample size calculation was performed in advance with a two-sided significance level of 5% and a power of 80%. Based on the previously reported effects of tourniquet application which range from 0.14\u0026ndash;0.87 mm, with a maximum standard deviation of 1.3 mm, a mean change of 0.505 mm in vein diameter was assumed [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The calculation of the sample size yielded 54 patients for our study. To account for a potential dropout rate of 10%, the study was planned with a final total of 60 patients.\u003c/p\u003e \u003cp\u003eData processing and analysis were performed using IBM SPSS Statistics (version 25; IBM, Armonk, NY, USA). Data are presented as median (Interquartile range [IQR]). Differences between measurements were evaluated using a paired Friedman test with Bonferroni-correction for multiple comparisons. Significance was set at P\u0026thinsp;\u0026lt;\u0026thinsp;0.05, also for Bonferroni-correction after mathematical adjustment was applied. The effect size for non-parametric testing was estimated using a z-statistic by calculating correlation coefficient \u003cem\u003er\u003c/em\u003e, with \u0026gt;\u0026thinsp;0.1 representing a small, \u0026gt;\u0026thinsp;0.3 a medium, and \u0026gt;\u0026thinsp;0.5 a large strength of association, according to the recommendations of Cohen [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. To analyze the accuracy of the measurements, the intra-class correlation coefficient was calculated between in-plane and out-of-plane measurements.\u003c/p\u003e \u003cp\u003ePatient demographics and hemodynamic/anesthesia data were reported as qualitative data and percentage or median [IQR], as applicable. Demographic as well as hemodynamic data and ventilation pressure settings were reported for transparency of the study cohort. No further statistical analyses were performed on this data.\u003c/p\u003e \u003cp\u003eOnly patients with complete data sets were included in the final data analyses.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eFor the final analysis, 57 patients with complete data sets were included (Fig. 2). Patients\u0026acute; characteristics are presented in Tab. 1. Hemodynamic data before and after induction of general anesthesia, as well as ventilator settings, were within normal range with a peak respiratory pressure of 15 [14-17] and a positive end-expiratory pressure of 5 [5-6]. The detailed data is provided in Supplemental Tab. 1. After awake measurements, GA was induced with propofol in all cases and supplemented with sufentanil/fentanyl in 32 (56%) or remifentanil in 25 (44%) cases. Maintenance of GA was performed with propofol in 37 (65%) and sevoflurane in 20 (35%) cases. 100 ml [50-230] of balanced isotone electrolyte solution was administered from induction of general anesthesia up to final measurements.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 1 Patient characteristics\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"595\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"60.33613445378151%\" valign=\"top\"\u003e\n \u003cp\u003eVariables\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.66386554621849%\" valign=\"top\"\u003e\n \u003cp\u003eTotal study sample (n=57)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"60.33613445378151%\" valign=\"top\"\u003e\n \u003cp\u003eAge, years (median [IQR])\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.66386554621849%\" valign=\"top\"\u003e\n \u003cp\u003e40 [27-51]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"60.33613445378151%\" valign=\"top\"\u003e\n \u003cp\u003eBMI, kg/m\u003csup\u003e2\u0026nbsp;\u003c/sup\u003e(median [IQR])\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.66386554621849%\" valign=\"top\"\u003e\n \u003cp\u003e24.2 [22.2-26.9]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"60.33613445378151%\" valign=\"top\"\u003e\n \u003cp\u003eSex (female), n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.66386554621849%\" valign=\"top\"\u003e\n \u003cp\u003e30 (53%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"60.33613445378151%\" valign=\"top\"\u003e\n \u003cp\u003eRight handed, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.66386554621849%\" valign=\"top\"\u003e\n \u003cp\u003e55 (97%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"60.33613445378151%\" valign=\"top\"\u003e\n \u003cp\u003emax\u0026deg; retroflexion, degree (median [IQR])\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.66386554621849%\" valign=\"top\"\u003e\n \u003cp\u003e75 [65-90]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eAbbreviations: BMI, Body mass index; IQR, Interquartile range; max\u0026deg; retroflexion, Maximum retroflexion in the shoulder joint\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eEffect of retroflexion, GA and tourniquet\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eA retroflexion of 30\u0026deg; or max\u0026deg; retroflexion in the shoulder joint was not associated with an increase in the CuV out-of-plane diameter compared to 0\u0026deg; within all conditions (Fig. 3, Tab. 2). CeV out-of-plane diameters did not show any effect of retroflexion, except for max\u0026deg; retroflexion compared to 0\u0026deg; in GA-NT (Fig. 4, Tab. 2).\u003c/p\u003e\n\u003cp\u003eThe application of a tourniquet resulted in a significant increase in the out-of-plane diameter of both CuV and CeV, with a greater effect size observed when used in combination with GA (Fig. 3-4).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eApplication of GA alone, without a tourniquet, had a significant but reduced effect on CuV out-of-plane diameter compared to tourniquet application (Tab. 2).\u003c/p\u003e\n\u003cp\u003eThe intra-class correlation coefficient for CuV-awake OD and ID measurements was found to be 0.952 [0.919-0.972], indicating excellent reliability. Similarly, the CeV-awake OD and ID comparison revealed a coefficient of 0.840 [0.728- 0.905], indicating good reliability of the measurement results.\u003c/p\u003e\n\u003cp\u003eAnalyzation of CuV-CI and CeV-CI measurements revealed comparable results for retroflexion, Tourniquet, and GA (Supplemental Tab. 2-3, Supplemental Fig. 2-3).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur findings indicate that using a tourniquet and/or general anesthesia can effectively increase peripheral vein width. However, retroflexion of 30\u0026deg; or max\u0026deg; does not have any effect on vein width in supine patients. Previous studies have not thoroughly analyzed the impact of upper limb retroflexion with tourniquet application and its effect on vein width while in the supine position. Additionally, this is the first study to include patients in both awake and anesthetized states in its analysis.\u003c/p\u003e\n\u003cp\u003eOnly one earlier work by Cappelletti et al showed an increase in the diameter and area of peripheral cephalic and basilic veins in healthy, awake subjects in the supine position with the arm dangling at a 90\u0026deg; angle compared with 0\u0026deg;\u0026nbsp;[18]. This contrasts sharply with our findings, possibly due to varying study conditions.\u003c/p\u003e\n\u003cp\u003eFirst, our maximum position was less retroflexed (65-90\u0026deg;) compared with a dangling arm. Cappelletti et al. analyzed solely awake patients, in consideration of the potentially increased risk of plexus affection, especially in anesthetized patients, we avoided a dangling arm\u0026nbsp;[15]. This should be considered in particular, as our awake evaluation of possible max retroflexion revealed, that 90\u0026deg; retroflexion cannot be achieved without paresthesia by most patients. Additionally, our work has shown a strong effect of the tourniquet. Therefore, it seems unlikely that gravity would have resulted in a significantly different effect for an arm bent backward 75\u0026deg; compared to an arm dangling 90\u0026deg;.\u003c/p\u003e\n\u003cp\u003eSecond, the measurements were performed in a more proximal position compared to our CeV measurements, resulting in different baseline vein widths. An evaluation by Yamagami et al. showed a larger baseline diameter than our CeV results at different measurement sites\u0026nbsp;[11]. Thus, different heights at the upper limb for measurement and lower consistency of the specific measurement point, compared to our setting, may further explain differences in baseline widths and results\u0026nbsp;[8, 19].\u003c/p\u003e\n\u003cp\u003eFurthermore, heat affects vein width, as peripheral vein width may also be affected by different room temperatures. This is reflected by larger baseline results in studies with slightly higher OR temps of 22-24\u0026deg;C, compared to our setting\u0026nbsp;[20, 21]. Besides room temperature, local warming or tapping are other, previously reported measures that can influence vein size\u0026nbsp;[6, 8, 20, 22]. It is uncertain whether these measures would affect our results for retroflexion. However, we avoided them to ensure the comparability of the measures evaluated.\u003c/p\u003e\n\u003cp\u003eOur in-plane measurements agree with the out-of-plane measurements and can thus be considered as a validation of our measurement procedures (Supplemental Fig.2-3). This good correlation between the different measurement approaches indicates that differences in skin pressure with the probe, which could lead to possible vein deformation, were effectively avoided.\u003c/p\u003e\n\u003cp\u003eIn contrast to many previous works that analyzed the effects on vein width only in healthy volunteers, our study is the first to examine patients before and after induction of anesthesia\u0026nbsp;[8, 10-12, 18-20, 22]. GA, and especially propofol, is known to decrease peripheral vascular resistance after induction\u0026nbsp;[23]. For this reason, in a clinical setting, often a small IV is first placed followed by a larger IV after anesthesia induction. Our findings confirm this effect of GA on peripheral vein widths. Additionally, gravidity-associated retroflexion revealed no further relevant enlargement, particularly in anesthetized patients, even when applying a tourniquet.\u003c/p\u003e\n\u003cp\u003eIn contrast to healthy volunteers, all our patients were fasted before surgery, which may affect venous filling, especially since fasting has been discussed as a cause of difficult venipuncture\u0026nbsp;[24, 25]. Previous research revealed controversial results regarding venous filling and reduced fluid intake during fasting. One study showed an increase in the cross-sectional diameter of the vena cava inferior after oral hydration in fasted patients\u0026nbsp;[26]. Sharp et al demonstrated a reduction in forearm vein diameter after rehydration in fasting patients and discussed sympathetic nervous system activation as a possible cause\u0026nbsp;[20]. Given these published controversial results, we administered fluids only at induction of general anesthesia and mostly in a \u0026quot;mild\u0026quot; form of less than 2 ml/kg body weight. Positive pressure ventilation can also act like a Valsalva maneuver and thus affect vein width\u0026nbsp;[27]. In our study, the respiratory settings were within ranges considered normal, without particularly increased respiratory pressures, and were not altered during measurements for individual patients.\u003c/p\u003e\n\u003cp\u003eWe chose to evaluate patients in the supine position because it is the usual position for IV access before general anesthesia as well as in pre- and intrahospital emergencies\u0026nbsp;[5, 28]. It has also been demonstrated that the size of the veins appears to be larger in the supine position than in the seated position\u0026nbsp;[11].\u003c/p\u003e\n\u003cp\u003eFurthermore, all measurements in our work were performed within a short period with comparable baseline conditions, which underlines the pronounced effect of tourniquet application.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePrevious results showed the use of a blood pressure cuff had the greatest effect on increasing vein size and decreasing vein compressibility compared to other tourniquet techniques\u0026nbsp;[29]. Sasaki et al. demonstrated an optimal effect of a blood pressure cuff on peripheral vein size enlargement when the cuff was inflated to a pressure of 60mmHg and applied for 30-60 seconds. After this time, there was no further increase in vein size\u0026nbsp;[10]. According to these previous findings, our patients remained in each condition for 60 seconds before measurements were performed and the strong effect of tourniquet application was confirmed in our work.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eLimitations of the study\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eIt is known that vein width is influenced by gender\u0026nbsp;[30], which was not explicitly analyzed in this work. Nevertheless, male and female participants were equally distributed in this work.\u003c/p\u003e\n\u003cp\u003eFor reasons of patient comfort as well as to avoid impairment of vein width by multiple punctures, cannula insertion at the measured extremity was omitted in all cases. IV puncture success was not measured and can only be estimated by vein width\u0026nbsp;[3, 4].\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe application of a tourniquet had the greatest effect on the dilation of peripheral veins in supine patients, especially in anesthetized conditions. Additionally, our findings showed a strong increase in vein widths after GA induction. In contrast, arm retroflexion, alone or in combination, showed no further effects on vein width.\u0026nbsp;\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eAP\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;anterior to posterior\u003c/p\u003e\n\u003cp\u003eAT\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Tourniquet application\u003c/p\u003e\n\u003cp\u003eBMI\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Body mass index\u003c/p\u003e\n\u003cp\u003eCeV\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Cephalic vein\u003c/p\u003e\n\u003cp\u003eCI\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Circumference\u003c/p\u003e\n\u003cp\u003eCuV\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Cubital vein\u003c/p\u003e\n\u003cp\u003eGA\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;general anesthesia\u003c/p\u003e\n\u003cp\u003eID\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Vein diameter in-plane\u003c/p\u003e\n\u003cp\u003eIQR\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Interquartile range\u003c/p\u003e\n\u003cp\u003eIV\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Intravenous\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eNT\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;without Tourniquet\u003c/p\u003e\n\u003cp\u003eOD \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Vein diameter out-of-plane\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSOP\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;standard operating procedure\u003c/p\u003e\n\u003cp\u003eSpO2 \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Peripheral oxygen saturation\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEthical approval was provided by the Ethikkommission der Charit\u0026eacute; - Universit\u0026auml;tsmedizin Berlin, Germany (Ethical Committee N\u0026deg; EA4/102/22). All patients were checked for eligibility and gave their written informed consent. The trial was registered prior to patient enrollment at WHO International Clinical Trials Registry Platform and German Clinical Trial Register (DRKS00029603). The study protocol was carried out in accordance with the Declaration of Helsinki and this manuscript adheres to the applicable CONSORT guidelines.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and analyzed during the current study are available from\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ethe corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors certify that there is no conflict of interest with any financial organization regarding the material discussed in the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003eFinancial support and sponsorship: This work was supported by the Department of Anesthesiology and Operative Intensive Care Medicine, Campus Benjamin Franklin, Charit\u0026eacute; \u0026ndash; Universit\u0026auml;tsmedizin Berlin, Germany.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCRediT authorship contribution statement\u003c/p\u003e\n\u003cp\u003eChristian Berger: Conceptualization; Methodology; Formal analysis; Investigation; Data Curation; Validation; Visualization; Writing - Original Draft; Project administration\u003c/p\u003e\n\u003cp\u003ePhilipp Brandhorst: Conceptualization; Investigation; Visualization; Writing - Review \u0026amp; Editing\u003c/p\u003e\n\u003cp\u003eElena Asen: Investigation; Data Curation; Writing - Review \u0026amp; Editing\u003c/p\u003e\n\u003cp\u003eSven Grallert: Investigation; Writing - Review \u0026amp; Editing\u003c/p\u003e\n\u003cp\u003eSascha Treskatsch: Conceptualization; Methodology; Resources; Writing - Review \u0026amp; Editing; Supervision\u003c/p\u003e\n\u003cp\u003eMoritz Weigeldt: Conceptualization; Methodology; Formal analysis; Investigation; Data Curation; Validation; Writing - Original Draft; Project administration\u003c/p\u003e\n\u003cp\u003eAll authors read and approved the final version of the manuscript\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCongresses\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eParts of this paper was presented as poster at the German Anesthesiology Congress (DAC 2023) that was held in D\u0026uuml;sseldorf on 27. - 29. April 2023.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSebbane M, Claret P-G, Lefebvre S, Mercier G, Rubenovitch J, Jreige R, et al. Predicting Peripheral Venous Access Difficulty in the Emergency Department Using Body Mass Index and a Clinical Evaluation of Venous Accessibility. J Emerg Med. 2013;44(2):299\u0026ndash;305.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTanabe H, Kawasaki M, Ueda T, Yokota T, Zushi Y, Murayama R, et al. A short bevel needle with a very thin tip improves vein puncture performance of peripheral intravenous catheters: An experimental study. J Vasc Access. 2020;21(6):969\u0026ndash;76.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePanebianco NL, Fredette JM, Szyld D, Sagalyn EB, Pines JM, Dean AJ. What you see (sonographically) is what you get: vein and patient characteristics associated with successful ultrasound-guided peripheral intravenous placement in patients with difficult access. Acad Emerg Med. 2009;16(12):1298\u0026ndash;303.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWitting MD, Schenkel SM, Lawner BJ, Euerle BD. Effects of vein width and depth on ultrasound-guided peripheral intravenous success rates. J Emerg Med. 2010;39(1):70\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLoon FHJv, Puijn LAPM, Houterman S, Bouwman ARA. Development of the A-DIVA Scale: A Clinical Predictive Scale to Identify Difficult Intravenous Access in Adult Patients Based on Clinical Observations. Medicine. 2016;95(16):e3428.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIchimura M, Sasaki S, Ogino T. Tapping enhances vasodilation for venipuncture even in individuals with veins that are relatively difficult to palpate. Clin Anat. 2020;33(3):440\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYamagami Y, Tomita K, Tsujimoto T, Inoue T. Tourniquet application after local forearm warming to improve venodilation for peripheral intravenous cannulation in young and middle-aged adults: A single-blind prospective randomized controlled trial. Int J Nurs Stud. 2017;72:1\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIchimura M, Sasaki S, Mori M, Ogino T. Tapping but not massage enhances vasodilation and improves venous palpation of cutaneous veins. Acta Med Okayama. 2015;69(2):79\u0026ndash;85.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSimons P, Coleridge Smith P, Lees WR, McGrouther DA. Venous pumps of the hand. Their clinical importance. J Hand Surg Br. 1996;21(5):595\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSasaki S, Murakami N, Matsumura Y, Ichimura M, Mori M. Relationship between tourniquet pressure and a cross-section area of superficial vein of forearm. Acta Med Okayama. 2012;66(1):67\u0026ndash;71.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYamagami Y, Inoue T. Patient Position Affects Venodilation for Peripheral Intravenous Cannulation. Biol Res Nurs. 2020;22(2):226\u0026ndash;33.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMahler SA, Massey G, Meskill L, Wang H, Arnold TC. Can we make the basilic vein larger? maneuvers to facilitate ultrasound guided peripheral intravenous access: a prospective cross-sectional study. Int J Emerg Med. 2011;4:53.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMbamalu D, Banerjee A. Methods of obtaining peripheral venous access in difficult situations. Postgrad Med J. 1999;75(886):459.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePeripheral TRIMBLET. I.V. starts: Vein preparation tips. Nursing2021. 2003;33(7):17.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCheney Frederick W, Domino Karen B, Caplan Robert A, Posner Karen L. Nerve Injury Associated with Anesthesia: A Closed Claims Analysis. Anesthesiology. 1999;90(4):1062\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang J, Moore AE, Stringer MD. Iatrogenic upper limb nerve injuries: a systematic review. ANZ J Surg. 2011;81(4):227\u0026ndash;36.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFritz CO, Morris PE, Richler JJ. Effect size estimates: current use, calculations, and interpretation. J Exp Psychol Gen. 2012;141(1):2\u0026ndash;18.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCappelletti S, Caimi A, Caldiroli A, Baroni I, Votta E, Riboldi SA, et al. Non-invasive estimation of vascular compliance and distensibility in the arm vessels: a novel ultrasound-based protocol. Quant Imaging Med Surg. 2022;12(7):3515\u0026ndash;27.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIchimura M, Sasaki S, Ogino T. Tapping enhances vasodilation for venipuncture even in individuals with veins that are relatively difficult to palpate. Clin Anat. 2020;33(3):440\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSharp R, Childs J, Bulmer AC, Esterman A. The effect of oral hydration and localised heat on peripheral vein diameter and depth: A randomised controlled trial. Appl Nurs Res. 2018;42:83\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003evan Bemmelen PS, Kelly P, Blebea J. Improvement in the visualization of superficial arm veins being evaluated for access and bypass. J Vasc Surg. 2005;42(5):957\u0026ndash;62.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYamagami Y, Tsujimoto T, Inoue T. How long should local warming for venodilation be used for peripheral intravenous cannulation? A prospective observational study. Int J Nurs Stud. 2018;79:52\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBoer F, Ros P, Bovill JG, Van Brummelen P, Van Der Krogt J, EFFECT OF PROPOFOL ON PERIPHERAL VASCULAR RESISTANCE DURING CARDIOPULMONARY BYPASS. Br J Anaesth. 1990;65(2):184\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCostantino TG, Kirtz JF, Satz WA. Ultrasound-guided peripheral venous access vs. the external jugular vein as the initial approach to the patient with difficult vascular access. J Emerg Med. 2010;39(4):462\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchoenfeld E, Boniface K, Shokoohi H, editors. ED technicians can successfully place ultrasound-guided intravenous catheters in patients with poor vascular access. Am J Emerg Med. 2011;29(5):496\u0026ndash;501.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDiaconu CI, Fox RJ, Grattan A, Rae-Grant A, Lu M, Gornik HL, Kim ES. Hydration status substantially affects chronic cerebrospinal venous insufficiency assessments. Neurol Clin Pract. 2013;3(5):386\u0026ndash;91.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVilla G, Chelazzi C, Giua R, Lavacchini L, Tofani L, Zagli G, et al. The Valsalva manoeuvre versus tourniquet for venipuncture. J Vasc Access. 2018;19(5):436\u0026ndash;40.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePaterson RS, Schults JA, Slaughter E, Cooke M, Ullman A, Kleidon TM, et al. Review article: Peripheral intravenous catheter insertion in adult patients with difficult intravenous access: A systematic review of assessment instruments, clinical practice guidelines and escalation pathways. Emerg Med Australas. 2022;34(6):862\u0026ndash;70.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKule A, Hang B, Bahl A. Preventing the collapse of a peripheral vein during cannulation: an evaluation of various tourniquet techniques on vein compressibility. J Emerg Med. 2014;46(5):659\u0026ndash;66.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKr\u0026ouml;ger K, Ose C, Rudofsky G, Roesener J, Weiland D, Hirche H. Peripheral veins: influence of gender, body mass index, age and varicose veins on cross-sectional area. Vasc Med. 2003;8(4):249\u0026ndash;55.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-anesthesiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bane","sideBox":"Learn more about [BMC Anesthesiology](http://bmcanesthesiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bane","title":"BMC Anesthesiology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"ultrasound, ultrasound guiding, venous access, patient safety, vein size, vein width","lastPublishedDoi":"10.21203/rs.3.rs-4368889/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4368889/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eIV access is a commonly performed procedure that is often taught based on tradition rather than evidence. The effect of arm retroflexion on vein width, either alone or in combination with a tourniquet or general anaesthesia (GA), remains unclear. In this case, the sonographically measured vein width is a surrogate parameter for the success of the puncture.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eProspective, cross-sectional study involving 57 patients scheduled for surgery in general anesthesia. We analyzed the impact of arm retroflexion, tourniquet, general anesthesia, and their combinations on the antebrachial veins in supine patients by ultrasound. Measurements were taken awake and during general anesthesia, each with and without the application of a tourniquet, and in three different arm positions (0\u0026deg;, 30\u0026deg;, and max\u0026deg; retroflexion) each. Data are presented as median and interquartile range [IQR].\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eTourniquet application (AT) had the greatest single effect on Cubital vein outer diameter (CuV-OD) compared to the baseline value of all measures (3.9 mm [3.4\u0026ndash;5.1]; 4.8 mm [4.1\u0026ndash;5.7], P\u0026thinsp;=\u0026thinsp;0.001, r\u0026thinsp;=\u0026thinsp;0.515). This effect was surpassed by the combination of AT and GA (5.1 mm [4.6\u0026ndash;6.6], P\u0026thinsp;=\u0026thinsp;0.001, r\u0026thinsp;=\u0026thinsp;0.889). In contrast, retroflexion alone did not result in an increase in the CuV\u0026ndash;OD at either 30\u0026deg; (4.2 mm [3.7\u0026ndash;5.1], p\u0026thinsp;=\u0026thinsp;1.0, r\u0026thinsp;=\u0026thinsp;0.12) or max\u0026deg; (4.2 mm [3.6\u0026ndash;4.9], p\u0026thinsp;=\u0026thinsp;0.72, r\u0026thinsp;=\u0026thinsp;0.23). With GA and AT, no further enlargement was measurable by 30\u0026deg; (5.4 mm [4.6\u0026ndash;6.6], p\u0026thinsp;=\u0026thinsp;1.0, r\u0026thinsp;=\u0026thinsp;0.15) or max\u0026deg; (5.4 mm [4.6\u0026ndash;6.6], p\u0026thinsp;=\u0026thinsp;1.0, r\u0026thinsp;=\u0026thinsp;0.07) retroflexion compared to GA-AT-0\u0026deg; (5.1 mm [4.6\u0026ndash;6.6], p\u0026thinsp;=\u0026thinsp;1.0, r\u0026thinsp;=\u0026thinsp;0.15).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eThis study provides evidence that retroflexion of the arm in supine patients, whether alone or in addition to a tourniquet or GA, does not have any additional effect on vein width as a surrogate parameter for successful IV success. It shows for the first time that general anesthesia effectively increase vein diameter.\u003c/p\u003e\u003ch2\u003eTrial registration\u003c/h2\u003e \u003cp\u003eDRKS00029603\u003c/p\u003e","manuscriptTitle":"Impact of arm position compared to tourniquet and general anesthesia on peripheral vein width in supine adult patients: A prospective, monocentric, cross-sectional study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-05-30 19:22:45","doi":"10.21203/rs.3.rs-4368889/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-05-17T09:45:03+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-05-15T06:55:48+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-05-15T06:55:48+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Anesthesiology","date":"2024-05-04T14:46:18+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-anesthesiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bane","sideBox":"Learn more about [BMC Anesthesiology](http://bmcanesthesiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bane","title":"BMC Anesthesiology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"8aa638ce-3e50-4f38-ad7a-b01fe26dfba6","owner":[],"postedDate":"May 30th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-10-28T16:06:05+00:00","versionOfRecord":{"articleIdentity":"rs-4368889","link":"https://doi.org/10.1186/s12871-024-02765-6","journal":{"identity":"bmc-anesthesiology","isVorOnly":false,"title":"BMC Anesthesiology"},"publishedOn":"2024-10-22 15:57:15","publishedOnDateReadable":"October 22nd, 2024"},"versionCreatedAt":"2024-05-30 19:22:45","video":"","vorDoi":"10.1186/s12871-024-02765-6","vorDoiUrl":"https://doi.org/10.1186/s12871-024-02765-6","workflowStages":[]},"version":"v1","identity":"rs-4368889","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4368889","identity":"rs-4368889","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}