Failed spinal anaesthesia for caesarean section

Spinal anaesthesia is the preferred regional technique for Caesarean section but failure sometimes occurs.

To determine the incidence of failure of spinal anaesthesia necessitating the conversion to general anaesthesia or the use of supplemental analgesia in women presenting for Caesarean section and to identify the contributory factor(s) to the failure.

It was a prospective study of 414 women who had spinal anaesthesia for Caesarean section.

The study was carried out in a University Teaching Hospital in South-Western Nigeria.

Women who had single-shot spinal anaesthesia for Caesarean section from April 2010 to March 2011 were prospectively studied using a standard proforma to record details of their demographic, clinical features, surgical and anaesthetic data and outcome.

The failed spinal anaesthesia rate in this study was 6.0%. The experience of the anaesthetist was a significant contributing factor for partial or complete failure necessitating conversion to general anaesthesia (p = 0.02). Intra-operative supplemental analgesic was required in 6.4% of those who had their surgery completed under spinal anaesthesia. Postpartum sterilization, exteriorization of the uterus during surgery, and surgical complications were significant risk factors for partial failure necessitating supplemental intra-operative analgesic.

Spinal anaesthesia conversion rate is high in this study when compared with reports from developed countries. Adequate training for residents in anaesthesia will decrease the failure rate. Parturients undergoing sterilization during Caesarean section may require supplementary analgesia.