Pain is considered as the fifth vital sign, and the need to control pain after surgery emphasizes its importance. Pain after surgery leads to unpleasant outcomes and effects on different mechanisms thus causes fundamental changes in the metabolism of the body of susceptible people. Accordingly, the current article aimed to compare two methods of pain control by the patient using PCA pumps compared to medicine injection to ease the pain by nurses.

Methodology: In the current research, a single-blind clinical trial of 70 patients as nominees of undergoing open-heart surgery at Shiraz Ordibehesht Hospital during 12 months was examined. The patients randomly divided into two groups of 35 patients with pain control by analgesia pumps of PCA and by NCA. The pain intensity was analyzed by visual analog scale (VAZ) and the sedation degree was examined based on the factors such as the Richmond sedation, nausea and vomiting and respiratory depression induced by opioids and analgesic effects, arterial oxygen saturation, patient satisfaction, ventilation duration for up to 48 hours after surgery. For data analysis, statistical software SPSS was used.

Results: No statistically clear distinction was seen in the status of nausea and vomiting as well as in the length of ventilation and the oxygen saturation status between the two groups. In none of the two groups, respiratory depression was observed. There was a statistically notable variation between the two teams regarding satisfaction level. Also, an increasing significant decline in pain intensity was noted in both groups at consecutive times. There was an experimentally meaningful distinction between the two teams regarding degree of sedation (P < 0.001), such that the level of sedation in NCA group was higher (P < 0.001).

Conclusion: The use of PCA pump in acute pain control after open cardiac surgery was better than the NCA. In the case of using the PCA pump, in addition to the psychological effect, the pump could control pain. Thus, the side effects of high dose injections would be reduced, and the increased use of the dose of drugs would not be detected.