Patient-controlled analgesia compared with nurse-controlled infusion analgesia after heart surgery

A randomized, controlled clinical trial was conducted on 66 patients undergoing elective cardiac surgery to compare patient-controlled analgesia (PCA) to nurse-controlled analgesia (NCA) with continuous morphine infusion. Hourly assessment of pain (at rest and on movement) using a visual analogue scale (VAS), of respiratory rate, and level of sedation took place for the 24h following extubation. The incidence of nausea was also recorded. Mean pain scores were calculated, and peak pain and sedation scores, together with lowest respiratory rates, were identified. Morphine consumption was measured at 24h. No significant differences were found between the groups' scores for pain or sedation. The PCA group had significantly lower respiratory rates (P = 0.02) and a lower incidence of nausea (P = 0.008). The PCA group also consumed significantly more morphine (P = 0.0001). The study suggests a beneficial effect from PCA after cardiac surgery in reducing nausea, compared to NCA. It confirms nurse-controlled infusion analgesia as an effective form of pain relief in an intensive care and high-dependency setting.