Pulmonary Hemodynamics in Patients with Pulmonary Hypertension Undergoing Repair of Atrial or Ventricular Septal Defect and Mitral Valve Replacement / 대한마취과학회지

BACKGROUND: The mechanisms of pulmonary hypertension(PHT) are usually quite different in acquired disorders of the left side of the heart from those of congenital heart disease. Accordingly, this study was designed to compare pulmonary hemodynamics immediately after cardiopulmonary bypass(CPB) in patients with undergoing repair of atrial(ASD) or ventricular septal defect(VSD) and mitral valve replacement(MVR). METHODS: 49 patients with PHT defined as a resting systolic pulmonary arterial pressure(SPAP) greater than 35 mmHg were studied and were divided preoperatively into two groups; repair of ASD or VSD(Group I, n=18) and MVR(Group II, n=31). Measurements were made after sternotomy and prior to initiation of CPB and upon stabilization following discontinuation of CPB. RESULTS: In group I, SPAP, DPAP and MPAP decreased by 44%, 22% and 35% respectively and pulmonary vascular resistance index(PVRI) decreased by 47% after CPB. In group II, SPAP, DPAP and MPAP revealed 25%, 32% and 29% reduction respectively and PVRI decrease by 39% after CPB. SPAP decreased more significantly after CPB in group I(44% vs 25%, p<0.05). CI increased significantly in group II while decreased in group I. Intraoperative inotropes and vasodilators were used more in group II than in group I(24/31 vs 6/18). CONCLUSIONS: The successful replacement of the valve and patch repair of defect may reduce both PAP and PVRI moderately in patients with PHT.

Comparison of Respiratory Effects of Continuous Flow CPAP System with Demand Flow CPAP System / 대한마취과학회지

BACKGROUND: Continuous positive airway pressure (CPAP) during spontaneous breathing has contributed greatly to the management of the neonatal respiratory distress syndrome and adult respiratory failure associated with acute lung disease. CPAP systems may be grouped into two general categories, demand flow CPAP system and continuous flow CPAP system. The purpose of this study was to evalute the respiratory effects of continuous flow CPAP system compared with demand flow CPAP system. METHODS: Cardiorespiratory values were measured in twelve respiratory failure patients on demand flow CPAP system and continuous flow CPAP system made by authors. CPAP level and FIO2 were maintained at the same level for both modalities. RESULTS: Changing from demand flow CPAP to continuous flow CPAP was associated with significant decrease in tidal volume(demand flow CPAP 450+/-153.0 ml, continuous flow CPAP 338+/-73.8 ml), airway pressure fluctuation(demand flow CPAP 6.4+/-1.2 cmH2O, continuous flow CPAP 2.4+/-0.7 cmH2O) and improvement in arterial oxygen partial pressure (demand flow CPAP 90.0+/-20.9 mmHg, continuous flow CPAP 105.9+/-24.6 mmHg). There were no significant changes in other cardiorespiratory values, such as arterial blood pressure, heart rate and respiratory rate. CONCLUSIONS: These results suggest that continuous flow CPAP system may be a beneficial modality in the management of respiratory failure patients compared to demand flow CPAP system.