Supplemental oxygen for Caesarean section under spinal anaesthesia

Background: Routine administration of supplemental oxygen to parturients undergoing Caesarean section under spinal anaesthesia has been criticised in recent times.Objectives: To assess the need for routine supplementary oxygen in healthy women undergoing Caesarean section under spinal anaesthesia in resource challenged setting and establish the efficacy of administration of oxygen at 4L/min.Design: Simple randomized trial using sealed envelopes.Setting: The Obafemi Awolowo University Teaching Hospital; a 580 bed hospital situated in Ile-Ife in South-western Nigeria.Subjects: Seventy parturients with ASA physical status I or Il undergoing Caesarean section under spinal anaesthesia.Main outcome measures: Outcome measures were arterial oxygen saturation (SaO2) and Apgar scores at one and five minutes.Results: The mean pre-induction arterial oxygen saturation in the two groups were similar. There was a statistically significant difference in the mean SaO2 at one minute between the two groups, with the control group being higher (97.7% ± 1.5% versus. 96.7% ± 1.5%; p-value = 0.008). The mean least SaO2 during surgery was also higher in the control group (95.9% ± 1.5% versus 94.9% ± 2.0%, p-value = 0.015). The Apgar scoreof the babies at one and five minutes for the study and control group were similar. Conclusion: Healthy parturients undergoing Caesarean section under spinal anaesthesia do well without supplemental oxygen; administration of supplemental oxygen from the common gas outlet of anaesthetic machine with the breathing circuit and standard anaesthetic facemask at 4L/min causes relative desaturation