BUPIVACAINE WOUND INFILTRATION IN THYROID-SURGERY REDUCES POSTOPERATIVE PAIN AND OPIOID DEMAND

Control of postoperative pain is an important element in preventing th e modification of the excitability of the dorsal horn neurons. We stud ied the efficacy of bupivacaine 0.5% wound infiltration for postoperat ive pain management following thyroid surgery. Forty consecutive ASA I -II patients, scheduled for thyroidectomy, were assigned randomly to t wo groups. Group I (n=20) consisted of patients receiving bupivacaine 0.5% (10 mi) wound infiltration at the end of surgery and group II (n= 20) included patients without infiltration. The patients did not know whether the wound had been anaesthetized or not. All patients received balanced inhalational anaesthesia, including fentanyl (a total dose o f up to 4 mu g.kg(-1)). Postoperative pain medication included morphin e IV or IM, as needed. Twenty-four hours after surgery the worst pain was recorded using a Visual analogue scoring system, from 0 to 10. Twe nty-four hour postoperative morphine requirement was recorded. Groups did not differ in demographic data. Pain scores were significantly dif ferent in the two groups. In group I, the mean pain score was 3.7+/-1. 6 compared with 6.9+/-1.7 in group II (P<0.05). Only six patients (30% ) in group I received opioids and only one of these (5%) had a pain sc ore above 5. In comparison, 18 patients (90%) in group II received mor phine during the first postoperative day. The local injection of bupiv acaine corresponds to a block of the superficial branches of the cervi cal plexus. This study demonstrated a simple, efficient and safe way t o reduce pain perception following a thyroidectomy.