Cardiorespiratory effects of nalbuphine and morphine premedication in adult cardiac surgical patients.

Premedication for cardiac surgical patients attempts to achieve relief of anxiety with minimal or no cardiorespiratory changes. Nalbuphine (NUBAIN) and morphine produced similar decreases in respiratory rate (1-3 breaths per min) and PaO2 (averaging 1.34 kPa), and increases in arterial PaCO2 (averaging 0.56 kPa). Cardiovascular changes were not seen with either agent. A similar degree of sedation and relief of anxiety was achieved with both drugs. Side effects were minimal and infrequent. Nalbuphine produces respiratory depression and sedation without cardiovascular changes which is comparable to an equivalent dose of morphine in patients with either valvular or coronary artery disease.