Low-flow oxygen delivery using a nasal cannula for apnoeic oxygenation in children undergoing elective surgery under general anaesthesia

Abstract

BACKGROUND Children have a smaller functional residual capacity and higher rate of oxygen consumption making them prone to develop hypoxaemia during a period of apnoea. The effectiveness of apnoeic oxygenation in preventing oxygen desaturation during laryngoscopy and intubation in small children has not been well studied. OBJECTIVE To assess the effectiveness of apnoeic oxygenation using a nasal cannula in preventing oxygen desaturation during laryngoscopy and intubation in children. DESIGN Prospective randomised double-blind controlled trial. SETTING Tertiary care teaching hospital between January 2020 and September 2021. PATIENTS One hundred and twenty children of 1 to 6 years age undergoing elective surgery requiring general anaesthesia with endotracheal intubation. INTERVENTION Patients were randomly allocated to receive 3 l min−1 oxygen by nasal cannula (apnoeic oxygenation group) or no oxygen (control group). Laryngoscopy and intubation was undertaken by a trainee anaesthesiologist. MAIN OUTCOME MEASURES The primary outcome was the lowest value of peripheral oxygen saturation (SpO2) during laryngoscopy and intubation. Secondary outcomes were the number of children whose SpO2 dropped to 95%, from 92% to < 95%, and below 92% and the incidence of bradycardia. RESULTS The mean ± SD of lowest SpO2 values was 99.95 ± 0.29% in the apnoeic oxygenation group and 98.37 ± 4.60% in the control group (P  = 0.009). No fall of SpO2 occurred in any patient in the apnoeic oxygenation group in spite of a longer apnoea time (P = 0.012). In the control group, 43 patients had no fall in SpO2 (P < 0.001), in 12 patients there was a fall in SpO2 to 95% (P  = 0.004), in one patient SpO2 fell to 92 to <95% (P  = 0.315) and in four patients SpO2 fell below 92% (P  = 0.038). There was no incidence of bradycardia. CONCLUSION Apnoeic oxygenation using a nasal cannula was effective in preventing oxygen desaturation during laryngoscopy and intubation in children as compared with those who did not receive apnoeic oxygenation. TRIAL REGISTRATION Clinical Trials Registry of India: CTRI/2020/01/022724 (www.ctri.nic.in).