The influence of head and neck position on ventilation with the i-gel airway in paralysed, anaesthetised patients

Context and objective We hypothesised that head and neck position could affect the effectiveness of ventilation with the i-gel airway. To test this hypothesis, we investigated the influence of different head and neck positions on oropharyngeal sealing pressures and ventilation scores during ventilation with i-gel. Methods A single, experienced supraglottic airway device user inserted the i-gel in 20 paralysed, anaesthetised patients who were scheduled for oral surgery. Oropharyngeal leak pressures and ventilation scores were measured with the head and neck in the neutral position, flexed, extended or rotated to the right. Ventilation was scored from 0 to 3 based on three criteria (no leakage with an airway pressure of 15 cmH(2)O, bilateral chest excursion and a square wave capnogram; each item scoring 0 or 1 point). Results Compared with the neutral position (25.8 +/- 5.2 cmH(2)O), oropharyngeal leak pressure was significantly higher with flexion (28.5 +/- 3.4 cmH(2)O, P = 0.015) and lower with extension (23.0 +/- 4.2 cmH(2)O, P = 0.015), but similar with rotation (26.7 +/- 5.1 cmH(2)O, P = 0.667). Flexion of the head and neck [2 (1-3)] adversely affected the ventilation score compared with the neutral position [3 (2-3), P = 0.004]. Conclusion Effective ventilation with an i-gel can be performed in patients in whom the head and neck is extended or rotated, whereas flexion of the head and neck adversely affects ventilation. Clinically, flexion of the head and neck should be avoided during ventilation with the i-gel. Eur J Anaesthesiol 2011;28:597-599