Loss of resistance: A randomised controlled trial assessing four low-fidelity epidural puncture simulators.

BACKGROUND: Detecting loss of resistance (LOR) can either be taught with dedicated simulators, with a cost ranging from &OV0556;1500 to 3000, or with the 'Greengrocer's Model', requiring simply a banana.

OBJECTIVES: The purpose of this study was to compare three dedicated epidural puncture training simulators and a banana in their ability to simulate LOR. Our hypothesis was that there was a difference between the four simulators when comparing the detection of LOR.

DESIGN: Single-blinded, randomised, controlled study.

SETTING: Department of Anaesthesiology and Pain Therapy, Bern University Hospital, Switzerland.

PARTICIPANTS: Fifty-five consultant anaesthesiologists.

INTERVENTIONS: The participants were asked to insert an epidural catheter in four different epidural puncture training simulators: Lumbar Puncture Simulator II (Kyoto Kagaku, Kyoto, Japan), Lumbar Epidural Injection Trainer (Erler-Zimmer, Lauf, Germany), Normal Adult Lumbar Puncture/Epidural Tissue (Simulab Corp., Seattle, Washington, USA) and a banana. The simulators were placed in identical boxes to blind the participants.

MAIN OUTCOME MEASURES: The primary outcome was the detection of LOR rated on a 100-mm visual analogue scale, in which 0 mm represented 'completely unrealistic' and 100 mm represented 'indistinguishable from a real patient'.

RESULTS: The mean visual analogue scale scores for LOR in the four simulators were significantly different: 60 ± 25 mm [95% confidence interval (CI), 55 to 65 mm], 50 ± 29 mm (95% CI, 44 to 55 mm), 64 ± 24 mm (95% CI, 58 to 69 mm) and 49 ± 32 mm (95% CI, 44 to 54 mm); P less than 0.001, Friedman test.

CONCLUSION: Two of the three dedicated epidural simulators were rated more realistic in detecting LOR than the banana, but some participants preferred the banana to the other three simulators. Given the relative cost of a banana compared with a dedicated simulator, we suggest that a banana be used to teach the technique of LOR for epidural puncture.

TRIAL REGISTRATION: KEK Nr: Req-2015-z087.