Hemodynamic reactions to the discontinuation of epidural analgesia and to the injection of Dolantin were studied in 16 patients. One of every three patients reacted to the postoperative pain with an increase in mean arterial pressure(+30%) and in the mean pressure in the arteria pulmonalis (+40%) associated with an increase in stroke volume (+41%) and cardiac output (+49%). The administration of Dolantin did not influence either pressure measurement. In such cases the administration of antihypertensive drugs (alpha-blocking agents) or the reinstitution of epidural analgesia is neccessary.