High-dose hydromorphone (Dilaudid) for coronary artery bypass surgery

The hemodynamic effects of high-dose hydromorphone hydrochloride (H), 1.25 mg/kg, were investigated in 10 patients with normal ventricular function undergoing coronary artery bypass graft (CABG) surgery. One patient with unstable angina was excluded from the study because of hypotension and facial flushing after a 6-mg test dose of H. Nine patients showed no significant change in heart rate (HR), mean arterial pressure (MAP), cardiac index (CI), left ventricular stroke work index (LVSWI), systemic vascular resistance (SVR), pulmonary capillary wedge pressure (PCWP), or coronary perfusion pressure (CPP) after H; central venous pressure (CVP) increased significantly (P less than 0.05). Loss of consciousness did not occur reliably after H. The addition of 50% N2O to H produced significant decreases in CI and LVSWI (P less than 0.05). Hemodynamic responses to tracheal intubation, skin incision, and sternotomy included depression of CI, elevation of SVR, and increased MAP (P less than 0.05). Vasodilators were required in eight patients before aortic cannulation and after extracorporeal circulation. Mean time to awakening was 7.6 hr after the full dose of H, and extubation was performed the morning after surgery (21 hr after H) according to our usual practice. We conclude that very large doses of H (equivalent in analgesic terms to 10 mg/kg of morphine sulfate) are well tolerated by most patients undergoing CABG surgery, but unconsciousness and complete suppression of sympathetic responses require supplementation of H with additional anesthetic agents or vasodilators.