Hacer Gizem Güliter, Mukadder Orhan Sungur, Tülay Özkan Seyhan, Demet Altun, Reyhan Nil KırşanDepartment of Anesthesiology, Istanbul University, Istanbul Medical Faculty, Istanbul, Turkey
BACKGROUND AND AIM: This study aimed to determine the minimum number of trials needed to be competent in ultrasound guided transversus abdominis plane (TAP) block using Cumulative Sum (CUSUM) analysis. Secondary endpoint was to examine the effects of demographical variables of residents or patients on success rate of procedure.
METHODS: Demographic data of ten anesthesiology residents and patients were recorded. TAP blocks were performed under supervision of a consultant anesthesiologist. Performances were rated according to a 10 point checklist (probe orientation, muscle plane visualization, needle, local anesthetic injection after right localization etc.). Trials with ?8 scores were accepted as successful. Learning curve plots were constructed using CUSUM calculations given in Table 1. Sample size was calculated according to acceptable success (80%) and unacceptable failure rate (40%) as 24 and 21 respectively. Forty six consecutive TAP blocks performed by each resident were analysed.
RESULTS: Five residents achieved proficiency in performing TAP block, whereas four were unsuccessful. No statistical assumption could be made for one resident as the learning curve is kept between decision limits (Figure 1). Among five proficient residents, mean number of successful trials was found to be 36 [29-45]. Minimum number of trials needed for gaining competency was found to be 45. Among examined demographical data, only competency on ultrasound skills was found to have an impact on success (p=0,02).
CONCLUSIONS: This study demonstrates that achieving competency in ultrasound guided TAP block varies between individuals and anesthesiology residents should perform minimum 45 trials for this procedure. Having a competency in ultrasound skills improves successful procedural rates. Learning curves constructed by CUSUM analysis can provide an objective assessment for individuals.