High flow nasal cannula oxygen preventing deoxygenation during induction of general anaesthesia in caesarean section: A randomized controlled trial

Abstract

BackgroundRecently high flow nasal oxygenation was used to prolong the safe apnoea period during induction of general anaesthesia. This randomized study was designed to compare between using transnasal humidified rapid insufflation ventilator exchange technique (THRIVE) and traditional face mask for preoxygenation in caesarean section. The primary aim was to measure the safe apnoea time. MethodsThe study was performed on 100 ASA II pregnant women scheduled for elective caesarean section under general anaesthesia. Patients were randomly assigned to either face mask ventilation or THRIVE. ResultsThe safe apnoea time was significantly longer under THRIVE with median of 7 min compared to facemask ventilation with 4 min. PaO2 with the facemask was 101 mmHg (74–215, median and range) after 3 min of apnoea vs. 355 mmHg (120–498) with THRIVE (P < 0.01). No statistically significant difference was found for PaCO2 between the two groups. ConclusionHigh humidified nasal flow oxygenation is more effective and practicable than face mask ventilation in improving oxygenation during induction of anaesthesia during caesarean section and might improve patients’ safety by avoiding desaturation.