Analgesic effect of intra-articular morphine after arthroscopic meniscectomy.

A study was performed to assess the analgesic effect of intra-articular morphine 2 mg in 33 patients undergoing elective arthroscopic meniscectomy. Patients were randomly allocated to receive either 2 mg of morphine hydrochloride in 40 ml of normal saline intra-articularly and 1 ml of normal saline intramuscularly (n = 18), or 40 ml of normal saline intra-articularly and 2 mg of morphine hydrochloride intramuscularly (n = 15). The latter group was to act as a control for any potential systemic effects of the morphine. All patients received an identical general anaesthesia consisting of propofol, alfentanil, enflurane and nitrous oxide/oxygen. No significant differences between the groups were found in pain scores at rest or during active flexion of the knee at 1-6 h postoperatively, or during walking at 6 h postoperatively (p > 0.05). Six and two patients in the intra-articular and intramuscular morphine group, respectively, requested supplemental morphine given intravenously (p > 0.05). In conclusion, no significant differences in pain scores or in requirements for supplemental morphine were observed between patients receiving intra-articular versus intramuscular morphine 2 mg after elective arthroscopic meniscectomy and consequently no specific local analgesic effect of intra-articular morphine could be demonstrated.

The effects of wound infiltration with bupivacaine versus saline on postoperative pain and opioid requirements after herniorrhaphy.

In a prospective, double-blind, placebo-controlled study, twenty-eight healthy, male patients, aged 20-69 years, scheduled for unilateral elective inguinal herniorrhaphy ad modum Bassini were randomized to receive postoperative infiltration of the surgical wound with either bupivacaine 0.25%, or isotonic saline. General anaesthesia was induced with thiopentone 3-5 mg.kg-1 and alfentanyl 10 micrograms.kg-1, and maintained with alfentanyl 5 micrograms.kg-1 15 min and N2O/O2. After herniorrhaphy, the internal fascia was infiltrated with bupivacaine 0.25% or saline, 10 ml. After closure of the external fascia, the subcutaneous tissue was infiltrated with bupivacaine 0.25% or saline, 15 ml on both sides of the surgical wound. Pain at rest, during mobilisation and during cough was significantly decreased in patients receiving bupivacaine compared to placebo. Median time to first request for morphine was increased from 25 min to 135 min, and the consumption of supplementary morphine during the 24 h study period reduced from four to two doses of 0.1 mg.kg-1 iv or 0.125 mg.kg-1 im, in patients who received bupivacaine compared to placebo.

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, randomized study. During surgery, all patients received a light general anaesthesia with thiopentone, alfentanil and nitrous oxide in oxygen. After induction of general anaesthesia, patients were allocated 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 patients were awake. Pain score on a visual analogue scale and on a verbal scale at rest, during mobilization from supine into sitting position and during cough was assessed 1, 2, 4, 6, 8 and 24 h, and 7 days after operation. No significant differences between the groups were observed in VAS scores or verbal pain scores during rest or ambulation at any time. There was no significant difference in time to first request for morphine or total morphine consumption. These results do not show pre-emptive analgesia with a conventional inguinal field block to be of clinical importance compared with a similar block administered after operation.