The use of high-dose intrathecal diamorphine in laparoscopic bariatric surgery: a single-centre retrospective cohort study.

Introduction: The use of intrathecal diamorphine is not commonplace in laparoscopic bariatric surgery. At our institution, a major UK bariatric centre, high-dose intrathecal diamorphine is routinely utilised.

Methods: Data were analysed retrospectively. Fifty-three patients who had a spinal anaesthetic were matched against age, sex, body mass index and surgical procedure type to generate controls. Pain scores were recorded in the post-anaesthetic care unit on arrival, after 1 hour and on discharge to the ward. Post-operative nausea and vomiting; post-operative hypertension; pruritus; 24-hour morphine consumption and length of stay were measured.

Results: Pain scores were better in the spinal anaesthetic group in all measured categories (p = 0.033, p < 0.01, p < 0.01); post-operative nausea and vomiting was less common in the spinal anaesthetic group (p < 0.01); post-operative hypertension was less common in the spinal anaesthetic group (p = 0.25); pruritus was more common in the spinal anaesthetic group (p < 0.01); morphine consumption was less common in the spinal anaesthetic group (p = 0.037). Length of hospital stay was reduced by 12.4 hours (p = 0.025).

Conclusion: We propose that this is a practical and safe technique to adopt. A randomised-control trial will need to be conducted in order to find the most efficacious volume of local anaesthetic and dose of diamorphine.