Impact of repeated simulation on learning curve characteristics of residents exposed to rare life threatening situations.

Background: Little is known about the learning curve characteristics of residents undertaking simulation-based education. It is important to understand the time for acquisition and decay of knowledge and skills needed to manage rare and difficult clinical situations. Method: Ten anaesthesiology residents underwent simulation-based education to manage a cannot intubate cannot ventilate scenario during general anaesthesia for caesarean section. Their performance was measured using an assessment tool and debriefed by two experienced anaesthesiologists. The parameters against which the performance was judged were grouped into preoperative assessment, preoperative patient care, equipment availability, induction sequence, communication and adherence to airway algorithm protocol. The scenario was repeated at 6 and 12 months thereafter. The residents' acquisition of knowledge, technical and non-technical skills were assessed and compared at baseline, 6 months and end of 12 months. Result: The skills of preoperative assessment, preoperative care and communication quickly improved but the specific skill of managing a difficult airway as measured by adherence to an airway algorithm required more than 6 months (CI at 6 vs 12 months: -3.4 to -0.81, p=0.016). The skills of preoperative assessment and preoperative care improved to a higher level quickly and were retained at this improved level. Communication (CI at 0 vs 6 months: -3.78 to -0.22, p=0.045 and at 6 vs 12 months : -3.39 to -1.49, p=0.007) and difficult airway management skill were slower to improve but continued to do so over the 12 months. The compliance to machine check was more gradual and showed an improvement at 12 months. Conclusion: Our study is unique in analysing the learning curve characteristics of different components of a failed obstetric airway management skill. Repeated simulations over a longer period of time help in better reinforcement, retention of knowledge, recapitulation and implementation of technical and non-technical skills.