Implementation and initial validation of a multicentre obstetric airway management registry

Abstract

Background: In Africa, maternal mortality after caesarean delivery is 50 times greater than in high-income countries. In South Africa, more than 50% of anaesthesia-related maternal mortality is attributed to failure to protect the airway. We implemented an obstetric airway management registry, to facilitate future improvements in management and outcomes.
Methods: A prospective electronic registry was established at three obstetric sites in Cape Town, recording airway management for all general anaesthetics from 20 weeks gestation to seven days post-partum. Perioperative descriptive data are entered using a web-based smartphone-enabled platform. To quantify the reliability of capture, we compared the first 200 records in the registry to theatre logbooks. We used summary statistics to describe our obstetric anaesthesia population, and details relevant to airway management.
Results: The first 200 cases were recorded from September 2018 to January 2019. According to theatre logbooks, this represented 80% of cases performed. Major indications for general anaesthesia included severe fetal distress/bradycardia (21%), failed neuraxial technique (19%), coagulopathy (19%), and abnormal placentation (12%). A third of patients had hypertensive disorders of pregnancy, and 6% had imminent/confirmed eclampsia. Forty per cent were in active labour. On airway assessment, Mallampati grade was 3 or 4 in 29% of patients, and mouth opening, thyromental distance and mandibular protrusion limited in 10%, 8% and 8% respectively. Cormack-Lehane grade IIb and III views were encountered in 6% and 2% respectively, with no grade IV views. Desaturation below 90% occurred in 12% of patients. There were two cases (1%) of failed intubation with supraglottic airway rescue, and no emergency surgical airways performed.
Conclusion: An obstetric airway management registry was successfully implemented. Clinically significant hypoxaemia occurred commonly during general anaesthesia, with a high incidence of difficult intubation predictors and desaturation. The registry will guide research aimed at improving safety during general anaesthesia in obstetrics.