Avoiding allogeneic blood transfusion during cardiac surgery and during the post-operative period is of great importance. Acute normovolemic hemodilution (ANH) is one of the options for blood salvage. We have prospectively analyzed 310 consecutive patients (pts) after different open heart procedures, operated on during April—May, 2000. ANH was possible in 226 pts (73%) with hemoglobin level over 125 g/l and hematocrit over 36%. Of those, one unit of blood was withdrawn in 128 pts (70%), while two to five units of blood were taken in 68 pts (30%). Total number of autologous blood units taken was 296, for the average of 1.31 units/pt. Predictors of increased intra- and post-operative blood loss were hematocrit (Hct) <39% (76% vs. 24%, p<0.001), age over 65 ( p=0.028), female sex ( p=0.006), CPB duration over 90 min (63% vs. 37%; p<0.001) and preoperative left ventricular ejection fraction (LVEF) <35% (63% vs. 37%; p<0.001). All pts with the above-mentioned characteristics were in need for allogeneic blood transfusion. During their hospital stay, 142 pts did not get allogeneic blood (142/310, 46%), and all were in the ANH group (142/226, 62%).

During mechanical ventilation high fluctuations of introthoracic pressures occur. No data have been presented as to the effects of positive pressure ventilation in patients with chronic obstructive pulmonary disease on the assessment of cardiac output from thoracic electrical bioimpedance. In order to evaluate a thoracic electrical bioimpedance system for the measurement of cardiac output, 40 paired values of cardiac output in 12 mechanically ventilated patients with chronic obstructive pulmonary disease were measured simultaneously with the standard thermodilution method. The data were plotted as the mean for the two measurement techniques versus the difference. The chosen acceptable difference for limits of agreement (mean difference +-2SD) was set at 22%. The mean difference was 0,1 liter per minute and standard deviation 0,7 liter per minute (12,2%). 92% of differences for two measurement techniques did not exceed the chosen acceptable difference.The two methods ore therefore considered to be in agreement. The continous and noninvasive nature of impedance method and its simplicity of use makes this technology very useful for the titration of drug and fluid therapy. It provides warning from impending problems which might require immediate treatment.