Modelling the incidence and severity of hypothermia during spinal anaesthesia for caesarean delivery: a prospective observational study in a resource-limited setting

Background: Core temperature changes during obstetric spinal anaesthesia are likely underestimated because monitoring is challenging and often not performed. This study aimed to describe the incidence and severity of perioperative hypothermia in patients undergoing caesarean delivery under spinal anaesthesia in a resource-limited setting. Methods: We performed a prospective observational study of parturients undergoing either elective or emergency caesarean delivery under spinal anaesthesia in a South African regional hospital. We used dual-sensor heat flux technology to monitor their core temperature during the perioperative period. The primary outcome was the incidence of clinically relevant hypothermia (defined as core temperature decrease from baseline of > 1 degrees C) following spinal anaesthesia. Smoothing splines were used to estimate maximum changes in core temperature. Results: We included 166 patients in our analysis. A decrease of > 1 degrees C occurred in 49% of participants (95% CI 40-63%) while hypothermia (temperature < 36 degrees C) occurred in 67% (49-78%). Discharge from recovery room with core temperature < 35 degrees C occurred in 26% (20-34%) of the participants. There was a higher incidence of vomiting in those participants who experienced temperature decreases of > 1 degrees C (18% vs 6%, p = 0.03). Conclusion: In this resource-constrained environment, clinically relevant hypothermia during obstetric spinal anaesthesia occurred in half of participants. Hypothermia was often severe and participants did not recover by the time of discharge from anaesthesia care. Monitoring of a patient's core temperature should be a standard of care, and further research into the clinical impact of perioperative hypothermia and warming strategies in these settings is warranted.