Acute effects of furosemide and mannitol on central haemodynamics in the early postoperative period.

The effects of furosemide and mannitol on central haemodynamics in the early postoperative period were investigated in 16 patients, who had undergone upper abdominal surgery. Measurements were performed prior to, and then 10, 30, 50 and 90 min after postoperative drug administration. Furosemide administration resulted in reductions of cardiac output, mean pulmonary arterial, pulmonary capillary wedge, and mean systemic arterial pressures, while systemic vascular resistance increased. Mannitol administration on the other hand, caused increases of cardiac output, mean pulmonary arterial and pulmonary capillary wedge pressures. Systemic vascular resistance decreased. It is concluded that mannitol should be used as the diuretic of choice in the treatment of postoperative (post-traumatic) oliguria in patients without known cardiovascular disease.