ABSTRACT
PURPOSE: To compare the duration of analgesia achieved following administration of buffered prilocaine versus plain prilocaine to patients undergoing surgical decompression of the median nerve. METHODS: 40 (32 female and 8 male; mean age, 50.5 years) patients who underwent surgical decompression of carpal tunnel syndrome were recruited. Patients were randomly allocated to 2 groups: the alkalinised group was given 10 ml of prilocaine hydrochloride 2% buffered with 1 ml of sodium bicarbonate 8.4%, whereas the non-alkalinised group received 10 ml of plain prilocaine hydrochloride 2% solution. Patients were asked to rate their comfort level at the operation site in the first 6 hours following surgery and after discharge from hospital using a visual analogue scale (VAS). The duration of analgesic effect was evaluated every 3 hours. Additional oral analgesia in the form of paracetamol 500 mg tablets was available to patients if required for break-through pain. RESULTS: Significantly lower VAS scores were reported by the alkalinised group during the first postoperative 12 hours. The change of VAS scores over time was significantly higher in the non-alkalinised group. The mean analgesic requirement for paracetamol tablets in the alkalinised and non-alkalinised groups was 4 and 34, respectively. CONCLUSION: Buffered prilocaine provided a longer postoperative pain-free period for patients undergoing surgical decompression of the median nerve. It is easy, safe, and cost-effective.
