The subjective experience of early postoperative pain following retrobulbar anaesthesia for enucleation and primary orbital implant.
We performed a prospective audit of the level of postoperative pain experienced by patients following enucleation with insertion of a primary orbital implant after preincisional regional retrobulbar anaesthesia using bupivacaine 0.75% with 1:100,000 adrenaline. An 11-point numerical ranking box scale was used to measure the subjective experience of postoperative pain following enucleation with insertion of a primary orbital implant in 40 patients with uveal melanoma. Surgery was performed under general anaesthesia with a supplementary peroperative retrobulbar injection of bupivacaine 0.75%/adrenaline 1:100,000. Pain scores were measured for the first 8 hours following administration of the block. The sample included 19 female and 21 male patients with a mean age of 66.7 years (31-87). At four hours post block, 80% were still pain free with 17% experiencing only mild to moderate pain (BS-11 = 1-4). Thirty-four (85%), twenty-eight (70%) and twenty-seven (67%) patients remained pain free at 2, 3 and 4 hours, respectively with no additional analgesia. The remainder scored BS-11 of 1-4 in 92% of cases. Twenty percent required supplementary analgesia (paracetemol in 78% cases) by 5 hours and 57% by 8 hours. BS-11 at 8 hours were 0 in 50%, 1-4 in 22% and 5-10 in 10% of patients (17% asleep). No complications using this technique were recorded. Using a preincisional retrobulbar injection of bupivacaine with adrenaline, BS-11 pain scores remained low with no or minimal additional analgesia for up to 4 hours post surgery. In combination with oral analgesia, effective pain control was provided in most cases for up to 8 hours post block.