Background: The measurement of intra-abdominal pressure (IAP) is an important examination in the diagnostics of multiorgan failure. Elevated IAP adversely impacts renal, splanchnic, pulmonary, cardiovascular, and central nervous system physiology. Therefore the measurement of IAP may be important in patients after CABG. The study analyzes IAP changes in patients undergoing surgical revascularization of the myocardium with extracorporeal circulation and normovolemic hemodilution.
Material/Methods: The study encompassed 21 men. The degree of NH caused by a constant volume of priming (1800 ml) was determined on the basis of hematocrit measurements and in relation to body weight. The
patients were divided into two groups according to body weight: ≤75 kg (group A) and >75 kg (group B). The observations were made in 10 stages: 1) after the induction of anesthesia, 2) during the internal thoracic artery preparation, 3) after the initiation of ECC, 4) during aorta clamping,
5) directly before the disconnection of ECC, 6) 10 minutes after ECC disconnection, 7) directly
after surgery, 8) one hour after the procedure, 9) 6 hours after the procedure, and 10) 18
hours after the procedure.
Results: Extracorporeal circulation caused a decrease in hematocrit in each patient. The CABG resulted
in increased IAP in both groups, but higher in group A. A signifi cant correlation between degree
of NH and IAP in group A was noted.
Conclusions: 1. The extracorporeal circulation procedures cause an increase in intra-abdominal pressure. 2. The increase in intra-abdominal pressure depends on the degree of hemodilution.

Keywords: Abdomen - physiology, Blood Pressure, Body Weight, Coronary Artery Bypass, Extracorporeal Circulation, Hemodilution, Multiple Organ Failure, Postoperative Period, Time Factors