The Bonfils fiberscope: a clinical evaluation of its learning curve and efficacy in difficult airway management.

BACKGROUND: This study evaluated the use of the Bonfils fiberscope by analyzing its learning curve, efficacy and safety during airway management. METHODS: This was a prospective observational study where five anesthetists, with differing levels of experience, were asked to use the Bonfils rigid fiberscope (Karl Storz) for a six-month period. They used the scope when performing endotracheal intubations in patients undergoing general anesthesia. The patients were excluded if various clinical indicators predicted that they might be difficult to intubate. The patient's head was kept in the neutral position to simulate the intubation of a trauma patient. Direct laryngoscopy with a Macintosh blade was performed to assign a Cormack and Lehane grade prior to attempting laryngoscopy with the Bonfils fiberscope. After intubating the patient with the Bonfils fiberscope, intubation time and any complications or failures noted after the procedure were recorded. RESULTS: The study included 216 patients, three of which were failed intubations. No complications occurred during the study period. The median intubation time was 21.43 s. The learning curve improved significantly after 20 intubations (P<0.05) and was affected by the operator's experience and aptitude with endoscopic viewing. Seventeen patients were deemed to have "unpredicted" difficult airways: 15 subjects with a Cormack grade 3 (6.9%) and two subjects with a Cormack 4 (0.9%). Median time to intubation in subjects with a Cormack <3 was 16 s (95% CI=10-29 s), and in subjects with a Cormack ≥3, it was 15 s (CI 95%=15-18 s) with P=0.703. CONCLUSION:The Bonfils fiberscope is an efficient, easy to use and safe device for endotracheal intubation.