Comparison of the effects of intravenous and thoracic epidural patient-controlled analgesia with morphine after upper abdominal surgery

Our purpose was to compare the effects of patient-controlled analgesia (PCA) with intravenous (i.v.) and epidural morphine on pulmonary function and their analgesic efficacy and side effects after upper abdominal surgery. In a prospective study, patients were randomly allocated to receive either thoracic epidural (n = 20) or intravenous (n = 20) patient-controlled analgesia with morphine. Preoperatively and at 24 and 48 h after surgery, arterial blood-gas analysis, forced vital capacity (FVC), and forced expiratory volume in 1s (FEV1) were measured, and chest X-ray films were taken from all patients. Pain (at rest), morphine consumption, nausea and vomiting, pruritus, and respiratory rate were recorded during the first 48 postoperative hours. In this period, the amount of morphine that was used in the epidural PCA group (28.5 +/- 7.4 mg) was significantly lower than in the i.v. PCA group (49.4 +/- 27.0 mg). Pain scores were similar in the two groups. Throughout the study no differences were found in pH(a), PaCO2, PaO2, FVC or FEV1 between epidural and i.v. morphine groups. When compared with preoperative data, at 24 and 48 h after surgery, FVC, FEV1, and PaO2 decreased significantly in both groups (p < 0.05). Except pruritus, incidence of side effects occurred similarly in the two groups. In this study, we found no difference between the effects of epidural and i.v. administration of morphine with PCA on pulmonary function and analgesic efficacy.