RELATIONSHIP BETWEEN INTRAOPERATIVE AND POSTOPERATIVE OXYGEN-TRANSPORT AND PROLONGED INTENSIVE-CARE AFTER CARDIAC-SURGERY - A PROSPECTIVE-STUDY

Background: Prolonged intensive care is a rare but serious complicatio n of cardiac surgery. It is required in less than 10% of operated pati ents but they use more than 30% of all the intensive care resources ne eded for cardiac surgery The aim of our study was to describe the clin ical course of the patients who need prolonged intensive care followin g cardiac surgery and to assess whether the intra- and postoperative o xygen transport variables are different in these patients as compared to patients with an uncomplicated course. Methods: The study patients were divided into two groups according to the length of stay in the in tensive care unit (ICU) after the operation: Group I, n=241, ICU-stay <5 days and Group II, n=20, ICU-stay greater than or equal to 5 days. Hemodynamic and oxygen transport data were prospectively obtained intr a- and postoperatively and postoperative organ dysfunctions were recor ded. Results: The patients in the prolonged intensive care group tende d to be older, have lower ejection fraction and longer cardiopulmonary bypass time. Postoperatively this group had significantly increased o xygen extraction rate (P=0.035, repeated measures for ANOVA). in the l ogistic regression analysis, increased oxygen extraction (31% in Group I vs. 36% in Group II, P<0.005) at 6 hours after arrival at the inten sive care unit had the strongest independent association with the need for prolonged intensive care. Conclusions: There was no significant r elationship between the factors conventionally assumed to be risk fact ors for prolonged intensive care, Instead, an increase in whole body o xygen extraction, reflecting a mismatch between the whole body oxygen demand and supply, was associated with the need for prolonged intensiv e care. Oxygen extraction increased to compensate for the reduced oxyg en delivery, which in rum was caused by a lower arterial oxygen conten t.