Pressure support ventilation during fibreoptic intubation under propofol anaesthesia

Goal of the study. To assess the benefit of pressure supportventilation during fibreoptic intubation performed under propofolanaesthesia in patients having an anticipated difficult intubation. Procedures. Thirty-two patients with ENT cancer, and havingat least two criteria for anticipated difficult intubation wereprospectively included. All patients received topical lidocaine2% and propofol by plasma target control infusion (initial targetconcentration 3 µg ml^–1, then adjusted to maintainloss of consciousness without apnoea). They were randomly assignedbetween two groups: spontaneous breathing (SB) or pressure supportventilation (with a support level set at 10 cm H₂O) both usingFI_O2=1. Conditions for fibreoptic intubation, respiratory parameters(pulse oxymetry, ventilatory frequency, tidal volume and after intubation) and haemodynamicparameters were recorded. Results. Patient characteristic data and intubation conditionswere similar between both groups. All patients had a successfulfibreoptic intubation and none needed a rescue procedure becauseof desaturation. In spite of a longer duration of intubation, after intubation was lower and tidal volume during intubation was higher with pressuresupport ventilation than in SB patients [38.1 (4.2) vs 42.3(4.7) mm Hg and 371 (139) vs 165 (98) ml, respectively]. Desaturationepisodes were observed in two SB patients conversely to no episodeduring pressure support ventilation, probably because of thehigher minute ventilation. Conclusion. Pressure support represents a useful method to improveventilation during fibreoptic intubation under propofol anaesthesiain patients with an anticipated difficult intubation. Presented in abstract at the ASA meeting 2003.