The Postoperative Analgesic Effect of Morphine and Paracetamol in the Patients Undergoing Laparotomy, Using PCA Method

Objective: postoperative pain increases the activity of the sympathetic system, causes hypermetabolic conditions, retains salt and water, increases glucose, fatty acid lactate and oxygen consumption, weakens the immunity system which delays wound healing.

Our object was comparison of the analgesic effect of morphine and paracetamol in the patients undergoing laparotomy, using PCA method.

Method: Seventy patients who had undergone laparotomy were studied using double blind randomized clinical trial (35 patients received morphine and 35 paracetamol) in the Shahid Rajaee Center and Velayat Hospital (Qazvin, Iran). People using opioids, painkillers and sedatives regularly and in large doses and patients with a history of lung or liver problems did not participate in this project. The parameters of the severity of pain and nausea (VAS), hemodynamic changes (BP and HR), pruritus, arterial oxygen desaturation and patient satisfaction (VAS) of both groups were measured by a third party (trained colleague). The data was analyzed using SPSS 16 statistical software then descriptive results were extracted and ultimately the groups were compared using the following statistical tests: student’s T-test, chi 2 and Fisher’s exact test (P<0.05).

Findings: The mean age of the participants was 45±12.5 years. Women constituted 24.3% of the patients and men 75.7%. The average pain severity for morphine and paracetamol groups (VAS) was 5.3±2.2and 6.37±1.7 after2 hours and reached 1.91±1.3 and 2.49±1.3 after 8 hours (after the operation) respectively. There was a significant difference between the groups after 2 and 4 hours in terms of pain severity (after 2 hours P=0.007 and after 4 hours P=0.047). However there was no significant difference between the average pain severity of the studied groups (after 6 hours P=0.4 and 8 hours P=0.08).

After 8 hours, the average nausea severity was the minimum in both groups being 1.71±1.6 and 1.43±1.1 in morphine and paracetamol groups respectively. Nausea severity was higher after 2 hours in paracetamol group. In morphine group, it was higher after 4, 6 and 8 hours. Difference between the groups was not significant. The average satisfaction level (VAS) for morphine and paracetamol groups reached from 5.29±2.3 and 4.2±2.4 after 2 hours, to 7.94±1.8 and 7.69±2.1 after 8 hours (after the operation), respectively. The average satisfaction level of patients was higher in morphine group in 2,4,6 and 8 hours and except for, after 4 hours (P=0.01), the satisfaction difference between both groups was not significant in other hours (P=0.06 after 2 hours, P=0.6 after 6 hours and P=0.5 after 8 hours)

Conclusion: Morphine seems to be more effective at 2 and 4 hours, but after 4 hours they have similar effects, the satisfaction difference between both groups was not significant in the patients.