The incidence and predictors of hypoxaemia during induction of general anaesthesia for caesarean delivery in two South African hospitals : a prospective, observational, dual-centre study

Abstract

Background: Caesarean delivery is the most commonly performed surgery in Africa. Morbidity and mortality linked to tracheal intubation represent a growing national health concern, yet there is minimal data relating to airway management in this group of patients. Methods: We conducted a prospective, observational, dual-centre cohort study with the aim of quantifying the incidence of hypoxaemia (SpO2 < 90%) at induction of general anaesthesia for caesarean delivery. We further aimed to explore body mass index, operator inexperience, predicted difficult airway, Cormack-Lehane grading and the absence of planned mask ventilation as predictors of hypoxaemia in our population. Airway complications were also quantified. Results: We included 363 patients in our study. The incidence of hypoxaemia was 61/363 (16.8%, 95% CI 13.29-21.02). High body mass index (> 30 kg/m2) and Cormack-Lehane grade (4) were predictive of hypoxaemia during induction. The failed intubation rate was 1.4% (95% CI 0.57–3.28) and the regurgitation rate was 0.8% (95% CI 0.27–2.54). There were no pulmonary aspirations and no surgical airways were required. Conclusion: The incidence of hypoxaemia during general anaesthesia for caesarean delivery is high. Future studies should examine methods to reduce the incidence of hypoxaemia, either through improved training or via specific interventions in this high-risk group.