[Postoperative pain therapy following total endoprosthetic surgery on the hip using a continuous 3-in-1 blockade]

40 patients who had undergone total hip replacement were included in a randomised prospective study. Postoperative pain management was performed with a continuous 3-in-1 block combined with demand-adapted intravenous meperidine titration (3-in-1 catheter group; n = 20) or by demand-adapted intravenous meperidine titration alone (control group; n = 20). The 3-in-1 catheter was placed before the start of anesthesia, and the patients received 30 ml 0.5% bupivacaine via this catheter. A second dose of 30 ml 0.5% bupivacaine was injected 10 min after postanaesthetic recovery. In the control group intravenous meperidine titration was initiated if the patients required pain relief. Subjective pain intensity was evaluated over a 6-hour period by means of the visual analogue scale. Bupivacaine plasma concentrations were determined in 18 patients at 30, 60, 120, and 180 min after the first postoperative injection of bupivacaine. Good pain control was achieved in both groups. The patients in the control group required a mean of 80.8 +/- 49.9 mg meperidine. The 3-in-1 block group required significantly less meperidine (54.3 +/- 44.5 mg). Mean bupivacaine plasma levels ranged between 0.75 and 1.33 micrograms/ml. Placement of the 3-in-1 catheters was without complications. For the management of postoperative pain following total hip replacement a continuous 3-in-1 block alone was often insufficient but postoperative meperidine requirements were significantly reduced (p < 0.05). Toxic bupivacaine plasma concentrations were not measured.