The study was undertaken to establish typical hemodynamic changes and reliable clinical tests for the evaluation of these in infants after open heart surgery. The cardiac index was measured using the thermodilution technique in 56 infants. The age of the patients varied from 6 to 28 months and body weight from 4 to 15 kg. All studies were done during the first 24 hours after operation. It was shown that in a hemodynamically smooth postoperative course cardiac index exceeds 2.7 l X min-1 X m-2, toe temperature (normal 32 degrees to 34 degrees C) and rectal-skin temperature gradient (normal 2 degrees to 3 degrees C) are normalized within 6 to 9 hours postoperatively. In case of low cardiac output syndrome, the cardiac index was below 2.5 l X min-1 X m-2, toe temperature was lowered to 26 degrees to 28 degrees C and the rectal-skin temperature gradient was 8 degrees to 10 degrees C. Big toe skin temperature correlated well with the magnitude of the cardiac index (r = 0.80; n = 247; p less than 0.001); stroke index (r = 0.70; n = 247; p less than 0.001); systemic vascular resistance (r = 0.64; n = 247; p less than 0.001) and urine output (r = 0.74; n = 247; p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

The study was undertaken to clarify the hemodynamic effects of intermittent positive pressure ventilation (IPPV) and intermittent mandatory ventilation (IMV) with variation of the positive end-expiratory pressure (PEEP) from 5 to 15 mbar. The cardiac index (CI) was measured with thermodilation techniques in 30 infants who underwent open-heart surgery with extracorporeal circulation for various congenital heart lesions. The age of the patients varied from 6 to 28 months and body weight from 4 to 15 kg. During IPPV the changing of PEEP levels up to 5 mbar did not have any effect on Cl. Further increase in the PEEP to 10 and 15 mbar caused a significant decrease in Cl (from 2.6 to 2.0 l.min-1.m-2, p less than 0.05). The oxygen consumption (VO2) did not change significantly (135 ml.min-1.m-2 to 128 l.min-1.m-2, p greater than 0.5). A positive end-expiratory pressure exceeding 5 mbar caused a decrease of intrapulmonary veno-arterial blood shunting (QS/QT) from 12.3 to 7.1%; p less than 0.01), while PEEP at the level of 5 mbar did not affect this parameter. The alveolo-arterial oxygen gradient (AsDO2) also decreased from 182 to 135 torr (p less than 0.01) when PEEP was 10 and 15 mbar.(ABSTRACT TRUNCATED AT 250 WORDS)

In this presentation our experience of the correction of large ventricular septal defects (VSD) under deep hypothermia (DH) and reduced flow rates in infants is reported. Sixty patients with VSD and pulmonary hypertension were operated. The age of the patients varied from 1.5 to 12 months and body weight from 3.0 to 8.7 kg. Deep hypothermia was achieved by cooling the patient using a heart-lung machine after aortic and right atrial cannulation. At a rectal temperature of 18 degrees C, pump flow was reduced to 0.28 l . min-1 . m-2 and cardiotomy was performed. Venous blood from the right atrium was aspirated with a single coronary sucker. The aorta was not clamped. After completion of the intracardiac repair, pump flow was increased and the patient was rewarmed to a rectal temperature of 36 degrees C. In all cases cardiac rhythm was restored spontaneously during rewarming. In every patients, the VSD was closed with a xenopericardial patch (in 42 patients from a right atrial approach and in 18 patients through the ventriculotomy). In 5 patients a patent ductus was also ligated and in 37 patients an atrial septal defect was sutured. The hospital mortality was 5% (3 patients). In the remaining 57 patients the cardiac index during the first 48 hours after operation was 2.5-4.2 l . min-1 . m-2. Patients were extubated between 18 and 44 hours after the operation. Deep hypothermia with reduced flow rates during intracardiac repair provides excellent myocardial protection and exposition in infants with VSD.