Frequency and predictors of failed spinal anaesthesia for caesarean section at Mthatha General Hospital.

Abstract

Background: Reported incidences of failure of spinal anaesthesia during caesarean section and the contributory factors vary widely across practices. Paucity of national guidelines for benchmarking acceptable failure rate in South Africa will impact on assessment of quality of care. This study, therefore, assessed the frequency of and associated factors of failure of spinal anaesthesia at Mthatha General Hospital in Eastern Cape, South Africa. Methods: Consecutive spinal anaesthesia performed in emergency and elective caesarean sections (n=200) from May to August, 2013 were included. The primary end was an outcome of the spinal anaesthesia. Demographic, obstetric, and anaesthetic data were collected to determine the factors associated with failed spinal anaesthesia. Results: Of the 197 participants included in the analysis, the frequency of failure of spinal anaesthesia was 11.7% (12.3% in emergency and 9.35% in elective Caesarean section). Prior anaesthesia (Relative risk [RR], 4.7; 95% Confidence interval [CI], 1.1-19.5), obesity (RR, 13.7; 95% CI, 5.4-34.7), dry tap of CSF (RR, 6.2; 95% CI, 2.5-15.2), bloody CSF (RR, 7.2; 95% CI, 2.6-20.4), and duration of work experience less than one year (RR, 4.1; 95% CI, 1.6-10.5) were associated with failed spinal anaesthesia. Multiple puncture attempts were associated with failed spinal anaesthesia. Hypotension and shivering occurred at higher rates of 39.1% and 16.2%, respectively in comparison to failed spinal anaesthesia. Conclusion: High frequency of failed spinal anaesthesia was observed in our practice setting. Risk factors for failure of spinal anaesthesia were; obesity, prior anaesthesia, bloody CSF and dry tap, and multiple puncture attempts. Training in general anaesthesia and protocols for managing other complications of spinal anaesthesia should be implemented in the hospital.