Background: The infraclavicular puncture of the subclavian vein is a standard procedure for anesthetists. Meanwhile the literature and recommendations are clear and the use of real-time ultrasound guidance is the standard procedure; however, anesthetists will always get into special circumstances were they have to use the landmark technique, so this competence must be preserved. Feared complications of infraclavicular subclavian vein puncture are pneumothorax and arterial puncture. Up to now there is no clear learning curve for the infraclavicular subclavian vein puncture in the landmark technique performed by anesthetists.
Objective: The aim of this study was to examine the influence of the puncture experience on the success rate and mechanical complications, such as pneumothorax and arterial puncture in patients who received an infraclavicular subclavian vein puncture with the landmark technique. Three levels of experience were defined for comparison: inexperienced 0-20 punctures, moderately experienced 21-50 and experienced over 50 punctures.
Material and methods: Post hoc analysis of a previously published noninferiority study to examine the influence of ventilation on the pneumothorax rate in the subclavian vein puncture using the landmark technique. This analysis included 1021 anesthetized patients who were included in the original study between August 2014 and October 2017. Demographic data as well as the number of puncture attempts, puncture success, the overall rate of mechanical complications, pneumothorax rate and arterial puncture rates were calculated.
Results: The overall rate of mechanical complications (pneumothorax + arterial puncture) was significantly higher in the inexperienced group (0-21) compared to the experienced group (>50, 15% vs. 8.5%, respectively, p = 0.023). This resulted in an odds ratio of 0.52 (confidence interval, CI: 0.32-0.85, p = 0.027). Likewise, the rate of puncture attempts in the group of inexperienced (0-20) with 1.85 ± 1.12 was significantly higher than in the group of experienced (>50, 1.58 ± 0.99, p = 0.004) and resulted in an odds ratio of 0.59 (CI: 0.31-0.96, p = 0.028). Although the puncture attempts of the moderately experienced (21-50) compared to the inexperienced (0-20) was not significant lower, we found an odds ratio of 0.69 (CI: 0.48-0.99, p = 0.042). The rate of successful puncture was 95.1% in the experienced group versus 89.3% in the inexperienced group (p = 0.001), which resulted in an odds ratio of 2.35 (CI: 1.28-4.31, p = 0.018). When viewed individually, no significant differences were found for pneumothorax and arterial puncture.
Conclusion: In this post hoc analysis of the puncture of the subclavian vein using the landmark technique, we found a significant reduction of puncture attempts and overall mechanical complications. At least 50 punctures seem to be necessary to achieve the end of the learning curve; however, the landmark technique should only be used under special circumstances, when real-time ultrasound is not available. Anesthetists who want to complete their repertoire and learn the landmark technique should always perform a static ultrasound examination before starting the puncture in order to reduce complications due to anatomical variations or thrombosis.
Zusammenfassung: HINTERGRUND: Die Punktion der V. subclavia gehört zu den Standardprozeduren eines/einer Anästhesisten/Anästhesistin. Gefürchtete Komplikationen dieser Prozedur sind der Pneumothorax und die arterielle Fehlpunktion. Zum Erlernen dieser Prozedur ist von einer gewissen Lernkurve auszugehen.
Ziel der arbeit: In dieser Studie soll der Einfluss der Punktionserfahrung auf die Erfolgsquote und mechanische Komplikationen wie Pneumothorax und arterielle Punktion untersucht werden. Dazu sollen 3 Erfahrungsstufen miteinander verglichen werden: unerfahren: 0 bis 20 Punktionen, mäßig erfahren: 21 bis 50 und erfahren: über 50 Punktionen.
Material und methoden: Post-hoc-Analyse einer vorab publizierten Nichtunterlegenheitsstudie zur Untersuchung des Einflusses der Beatmung auf die Pneumothoraxrate bei der V.-subclavia-Punktion in Landmarkentechnik. Es wurden 1021 Patienten ausgewertet, die in die vorab publizierte Studie zwischen August 2014 und Oktober 2017 eingeschlossen wurden.
Ergebnisse: Die Gesamtrate an mechanischen Komplikationen ist in der Gruppe der Unerfahrenen im Vergleich zur Gruppe der Erfahrenen signifikant höher (15 % vs. 8,5 %, p = 0,023). Ebenso ist die Rate an Punktionsversuchen in der Gruppe der Unerfahrenen (0–20) mit 1,85 ± 1,12 signifikant höher als in der Gruppe der Erfahrenen (1,58 ± 0,99, p = 0,004). Im Gegenzug war die Rate einer erfolgreichen Punktion mit 95,1 % in der Gruppe der Erfahrenen signifikant höher als in der Gruppe der Unerfahrenen (89,3 %, p = 0,001).
Schlussfolgerung: Für eine erfolgreiche Punktion der V. subclavia in Landmarkentechnik ist eine Lernkurve von mindestens 50 Punktionen nötig, um die Komplikationsrate zu senken und die Erfolgsrate zu steigern.
Keywords: Central venous catheter; Education; Intensive care; Learning curve; Pneumothorax.