At the time of their transfer to the ICU, patients were randomized into PL and RF Groups. Parenteral administration of the two solutions was initiated immediately after collection of the first blood sample at 166 mL/hour. Thus, all patients received 1000 mL of infusion solution over 6 hours. Patients requiring more rapid fluid replacement due to postoperative hypovolemia were excluded from the study. Patients were routinely rewarmed with a warm air blanket and received humidified oxygen via a face mask or, in case of good oxygenation, via a nasal cannula.