Intravenous patient-controlled analgesia after thoracotomy: a comparison of morphine with tramadol

BACKGROUND AND OBJECTIVE: This study examined the quality of analgesia together with the side-effects produced by tramadol compared with morphine using intravenous patient-controlled analgesia during the first 24 h after thoracotomy. METHODS: Forty-four patients scheduled for thoracotomy were included in the study. Morphine 0.3 mg kg(-1) was given interpleurally 20 min before a standard general anaesthetic. In the postanaesthetic care unit, the patients were randomly allocated to one of two groups to self-administer tramadol or morphine using a patient-controlled analgesia device throughout a 24 h period. The patient-controlled analgesia device was programmed to deliver tramadol 20 mg as an intravenous bolus or morphine 2 mg with a lockout time of 10 min. RESULTS: Mean cumulative morphine and tramadol consumption were 48.13 +/- 30.23 and 493.5 +/- 191.5 mg, respectively. There was no difference in the quality of analgesia between groups. Five (26.3%) patients in the tramadol group and seven (33%) in the morphine group had nausea, and three of the latter patients vomited. The incidence rate of vomiting with tramadol was 5.2%. All vital signs were within safe ranges. Sedation was less in the tramadol group, but not statistically significant. CONCLUSIONS: In this clinical setting, which includes interpleural morphine pre-emptively, postoperative analgesia provided by tramadol was similar to that of morphine at rest and during deep inspiration. Side-effects were slight and comparable between the patients receiving morphine and tramadol.