Objective:
To compare the effects of intravenous patient controlled analgesia(IV-PCA) with meperidine or morphine on hemodynamic parameters and pain control after thoracotomy operations.
Methods:
In this prospective study, 140 patients (ASA I-III) were randomly divided into meperidine (Group 1) and morphine (Group 2) groups. For IV-PCA in the postoperative first 24 hours, in Group I; a 50 mg loading dose, 7 mg hr-1 basal infusion, 5 mg demand dose, while, in Group II; a 5 mg loading dose, 0.5 mg hr-1 basal infusion, 0.5 mg demand dose was given,and the lock-out time was 15 minutes for both groups. The collected parameters included; systolic, diastolic, mean arterial blood pressures, heart rate, pulse-oximeter saturation, visual analog scala (VAS) and Ramsey sedation scale scores, total and additional analgesics amounts and side effects.
Results:
The VAS scores at 2, 4, 16. hours in Group 1 were significantly higher than in Group 2 (p=0.08; p=0.014; p=0.031). Within group analysis revealed decreased VAS scores in comparison to preoperative values in both groups (p=0.0001). Total and additional doses of morphine in Group 1 (calculated equivalent morphine dose depending on 25% incomplete cross tolerance) were higher than Group 2 (p=0.001, p=0.0001). Systolic, mean blood pressures at 2, 4, 8, 16 hours and diastolic blood pressures at 2, 4, 8 hours were higher in Group 1 when compared to Group 2 (p<0.05). The incidence of hypotension in Group 1 was 7.1%, being lower than Group 2 (18.6%; p=0.043).
Conclusion:
During post-thoracotomy pain therapy, IV-PCA with morphine provides more efficient analgesia than with meperidine. However, as hypotension is more commonly observed with morphine, its use is limited and requires a cautious approach.
Keywords: Thoracotomy, pain, patient controlled analgesia, meperidine, morphine