EFFECT OF PRE- VS POSTOPERATIVE INGUINAL FIELD BLOCK ON POSTOPERATIVE PAIN AFTER HERNIORRHAPHY

The analgesic effects of an identical inguinal field block,performed before or immediately after inguinal herniorrhaphy,were evaluated in 32 healthy patients in a double-blind, randomizedstudy. During surgery, all patients received a light generalanaesthesia with thiopentone, alfentanil and nitrous oxide inoxygen. After inducation of general anaesthesia, patients wereallocated randomly to receive an inguinal field block with lignocaine,either 15 min before operation or immediately after operation,after closure of the surgical wound, but before the patientswere awake. Pain score on a visual analogue scale and on a verbalscale at rest, during mobilization from supine into sittingposition and during cough was assessed 1, 2, 4, 6, 8 and 24h, and 7 days after operation. No significant differences betweenthe groups were observed in VAS scores or verbal pain scoresduring rest or ambulation at any time. There was no significantdifference in time to first request for morphine or total morphineconsumption. These results do not show pre-emptive analgesiawith a conventional inguinal field block to be of clinical importancecompared with a similar block administered after operation.