[Open heart surgery with bloodless priming for ventricular septal defect and pulmonary hypertension].

In 17 patients with ventricular septal defect and pulmonary hypertension (VSD, PH) weighing 5.2 kg to 9.5 kg, open heart surgery was conducted with bloodless priming (total priming volume: 370-470 ml). None of the patients required blood transfusion during their hospital stay. The post-operative respiratory status was excellent in all cases with duration of intubation being 6 +/- 3 hours. While 12 patients weighing over 6.6 kg maintained individual constant hematocrit (Hct) values during cardiopulmonary bypass (CPB), all 5 patients weighing under 6.1 kg showed significant decrease during rewarming (17 +/- 2% after initiation of CPB to 14 +/- 2% during rewarming). The lowest Hct value was 12% during rewarming in 6.0 kg infant. The pre-operative circulating blood volume (CBV) was calculated retrospectively from the priming volume, the Hct value after anesthetic induction and the Hct value after initiation of CPB. The relationship, CBV (ml) = body weight (kg) x 72-13 (r = 0.85, p < 0.01) was derived. Using this equation, we calculated the predicted Hct level after initiation of CPB using the 370 ml bypass circuit in 43 VSD PH patients weighing 3.4 kg-5.9 kg. The Hct values were 17 +/- 2% in 13 patients weighing over 5 kg with 12 (91 percent) above 15%, and 13 +/- 2% in 30 patients weighing under 4 kg with 3 (11 percent) above 15%. Hct levels of 34%-36% before CPB were essential in patients weighing 4.0 kg-4.9 kg for the Hct level after initiation of CPB to exceed 15%.(ABSTRACT TRUNCATED AT 250 WORDS)