[Quality of postoperative pain therapy: evaluation of an established anesthesiology acute pain service].

BACKGROUND: Despite well-designed concepts of perioperative pain management, recent studies have revealed that a large number of patients still suffer from unacceptable pain after surgery. The purpose of this prospective evaluation was to critically analyze postoperative pain treatment provided by a routinely established, DIN certified acute pain service (APS) at the University Hospital Großhadern in Munich.

MATERIALS AND METHODS: A total of 1,000 consecutive patients received one of the following analgesic procedures: continuous epidural analgesia (EA, n = 401), continuous and patient-controlled epidural analgesia (PCEA, n = 305), intravenous patient-controlled analgesia with opioids (PCA, n = 169) or continuous peripheral nerve block (CPNB, n = 125). For EA and PCEA, ropivacaine 0.2 % and sufentanil 0.24 µg/ml were administered while peripheral regional analgesia was performed with infusion of ropivacaine 0.2 % only. Patients with PCEA were allowed a 3 mg bolus once per hour on demand. Standardized intravenous PCA was performed with piritramide 2.5 mg/ml, a bolus of 2.5 mg, a lock-out time of 15 min, a maximum of 25 mg/4 h and no background infusion. During the daily visits the APS assessed pain intensity at rest and during movement on a numerical rating scale from 0 (no pain) to 10 (maximum pain), acceptance of pain, satisfaction with the analgesic procedure, demand of additional non-opioid analgesics, the need for optimization including bolus applications and changes of the infusion rate or retraction of the epidural catheter. The duration of the procedures, side effects and complications were documented. The catheter insertion sites were inspected daily for redness and tenderness on palpation.

RESULTS: In general, epidural and peripheral regional analgesic techniques were superior in terms of postoperative analgesia to intravenous opioid PCA and were associated with fewer side effects, such as sedation, nausea, vomiting, obstipation and sensorimotor deficits. A subgroup analysis revealed that in major upper abdominal surgery, EA provided significantly better analgesia at rest and during movement than PCA. In lower abdominal surgery PCEA induced significantly better analgesia than both PCA and EA, especially during movement. Patient satisfaction was generally high and was best with PCEA (95 %) followed by CPNB (94 %), EA (91 %) and PCA (88 %). On the first postoperative day analgesic procedures had to be optimized (e.g. by bolus administration, retraction of catheters or changes to standardized PCA) in 23 % of EA patients, 10 % of PCEA patients, 6 % of PCA patients and 12 % of CPNB patients. Major complications, such as neuraxial hematoma, infections or respiratory depression were not observed.

CONCLUSIONS: As described in many prospective studies, this evaluation revealed that for postoperative pain control, regional anesthesia is superior to intravenous patient-controlled analgesia with strong opioids in terms of analgesia and side effects. In the setting of a well-organized acute pain service with frequent education and training of all members involved, postoperative pain management is safe and effective. However, regular re-evaluation of the defined and certified procedures is necessary.