Flexible fibreoptic bronchoscopy via the laryngeal mask

The efficacy of flexible fibreoptic bronchoscopy through the laryngeal mask was investigated in 20 patients under total intravenous anaesthesia with propofol, fentanyl, atropine and suxamethonium. Mask size 4 was used for men and size 3 for women. Ventilation was performed with oxygen in air, FIO2 0.6. The ventilatory pressures were median 18 (9-40) cmH2O (1.8 (0.9-3.9) kPa) before the bronchoscope was inserted. When the tip of the bronchoscope was above the vocal cords the ventilatory pressures increased to 22 (10-43) mmHg (2.2 (1.0-4.2) kPa) (P < 0.001), and when the tip was situated at the mid-tracheal level there was a further increase to 24 (12-50) mmHg (2.4 (1.2-4.9) kPa) (P < 0.001). Maximal gas leakages were median 1 (0-2) l/min-1. PEEP at the mid-tracheal level was 3 (0-7) cmH2O (0.3(0-0.7) kPa). When 15 min of the procedure had elapsed, PaO2 was 232 (112-350) mmHg (30.9 (14.9-46.6) kPa) and PaCO2 39 (33-46) mmHg (5.2(4.4-6.1) kPa). The lowest oxygen saturation was median 98 (96-100)% and the highest end-tidal CO2 34 (24-41) mmHg (4.5(3.2-5.5) kPa). It was easy to examine the laryngeal opening and a good assessment of vocal cord function was allowed when muscle relaxation ceased. We conclude that flexible fibreoptic bronchoscopy through the laryngeal mask is a safe technique provided that total intravenous anaesthesia is used. It is a valuable alternative to flexible bronchoscopy performed with topical anaesthesia.