Effectiveness of tip rotation in fibreoptic bronchoscopy under different experimental conditions: an in vitro crossover study.

Background: Proper manipulation of fibreoptic bronchoscopes is essential for successful tracheal intubation or diagnostic bronchoscopy. Failure of proper navigation and rotation of the fibrescope may lead to difficulties in advancing the fibrescope and might also be responsible for (unnecessary) difficulties and delays in fibreoptic tracheal intubation, with subsequent hypoxaemia. The present study, therefore, aimed to assess the effectiveness of tip rotation in flexible bronchoscopes in different experimental conditions.

Methods: Five differently sized pairs of fibrescopes (outer diameters of 2.2, 2.4, 3.5, 4.2, and 5.2 mm) were inserted into paediatric airway manikins via an appropriately sized laryngeal mask and were turned clockwise or anticlockwise at the fibrescope body or cord to 45, 90, and 180°, with the cord held either straight or bent. The primary outcome measure was the ratio of rotation measured at the tip over the rotation performed with the fibrescope body or cord.

Results: Overall, the 'body' turn was significantly less effective when a bent cord was present (mean difference ranging from 29.8% (95% confidence interval 8.8-50.9) to 117.4% (93.6-141.2). This difference was diminished when the 'cord' turn was performed. Smaller fibrescopes, with outer diameters of 2.2 and 2.4 mm, were inferior with respect to the transmission of 'body' rotation to the tip.

Conclusions: 'Cord' turning of the fibrescope appears to be more effective in rotating the tip than a turn of the fibrescope 'body' only. Straightening the fibrescope cord and combined 'body' and 'cord' turning are recommended.