[Patient-controlled postoperative epidural analgesia. Prospective study of 1799 patients]

Side effects of postoperative epidural analgesia can be controlled by two strategies: Insertion of catheters into the center of the affected spinal segments and coadministration of local anesthetics and opioids. Both techniques will reduce single drug dosage. Additionally synergistic effects will result in excellent analgesia and the risk of side effects and complications will be minimized.

Between september 1995 and february 1997 the pain-service of the Klinik and Poliklinik für Anästhesiologie und operative Intensivmedizin der Westfälischen Wilhelms-Universität Münster has used this regimen to treat 1799 postoperative patients with patient-controlled epidural analgesia. All patients received an infusion of bupivacaine 0.175%, which was combined with sufentanil 1 microgram/ml in adults under the age of 70 an in children with a body weight > 30 kg. The infusion was adjusted to the individual needs of the patients by a visual analogue scale (VAS-scale: 1 = no pain; 10 = worst pain possible). Analgesia was adequate if VAS-scores were < 4 during rest and < 7 during movement and coughing. The continuous drug administration was combined with additional patient-controlled bolus doses. Postoperatively a special observation period to monitor side effects of epidural sufentanil was not defined. All patients were admitted to wards as soon as they fulfilled common criteria for discharge from the recovery room.

Mean VAS-scores during the postoperative observation-period were within the prior defined limits. On the morning after surgery, however, a reduction in pain relief was observed and analgesia on the first postoperative day could significantly be improved after a 24-h on call pain service has been introduced. Except urinary retention side effects are rare. Probability of motor-blockade is significantly lower in patients with thoracic compared to patients with lumbar catheters. Not any patient suffered from severe complications such as sedation or respiratory depression.de