Learning curves for fibreoptic nasotracheal intubation when using the endoscopic video camera

We have followed the progress of 12 anaesthetic trainees as they learnt how to perform fibreoptic nasotracheal intubation with the aid of an endoscopic video camera system. Each trainee had a structured teaching session on a bronchial tree model, viewed an instructional videotape and then performed 20 nasotracheal intubations on anaesthetised oral surgery patients. Trainees were required to perform the endoscopies under full visual control and to demonstrate airway anatomy as they advanced the fibrescope. They were allowed up to two 2 1/2 min periods to complete nasotracheal endoscopy. All 240 endoscopies were completed within the time limit: 228 were completed within 2 1/2 min and 12 (5%) were completed during the second 2 1/2 min period. We constructed a group learning curve from the pooled data. The half-life of the curve was nine endoscopies. The best fit value for the first endoscopy time was 132 s, and after the 18th (two half-lives) it was 49 s. We analysed the theoretical basis for deriving a learning curve from raw data. This information could form a rational basis for the design of fibreoptic training programmes using video imaging systems.