Single-shot spinal diamorphine for laparoscopic nephrectomy: A retrospective study.

Single-shot spinal diamorphine is becoming common practice in urological surgery to aid post-operative pain; however, its safety and efficacy require investigation. This study is a retrospective analysis of 113 laparoscopic or robotic-assisted nephrectomies over 4 years under one consultant urologist. Data were collected on demographic, pre-operative scores, anaesthesia, surgical information, post-operative outcomes and opioid consumption. Two main groups were established: no spinal diamorphine (NSD) and spinal diamorphine (SD). Four subgroups were then created, separating those who received patient-controlled anaesthesia (PCA) or not: Group 1 [general anaesthetic (GA)]; Group 2 [GA and PCA]; Group 3 [GA and spinal diamorphine] and Group 4 [GA, spinal diamorphine and PCA]. Ninety-eight eligible patients were identified. At 6 hours, pain scores were significantly higher for all non-spinal groups (p < 0.05); at 9 h, pain scores were significantly higher in NSD patients compared to SD (p = 0.026); at 12 h, pain scores were significantly higher for NSD patients compared to SD (p = 0.024), and Group 1 compared to Group 3 (p = 0.023). Total opioid consumption in the first 24 h post-surgery was higher in Group 1 compared to Group 3 (p = 0.024). There was no higher incidence of urinary retention, or any neurological complications reported within the SD patients. The study found a reduction in post-operative pain scores with the use of spinal diamorphine prior to laparoscopic and robotic-assisted nephrectomies. The findings may also suggest that pre-operative spinal diamorphine use can reduce the total volume of opioids administered via other routes in the first 24 h post-operatively. It recommends its routine administration but encourages prospective investigation.