CONTINUOUS NEGATIVE EXTRATHORACIC PRESSURE AND CARDIAC-OUTPUT - A PILOT-STUDY

Continuous negative extrathoracic pressure (CNEP) has been recently re introduced as therapy for respiratory failure. To determine its effect s on cardiac output a pilot study was performed in ten patients aged 2 months-3 years (median 4 months). All had chronic respiratory failure (seven with bronchopulmonary dysplasia). Five were breathing spontane ously and five were intubated and undergoing intermittent positive pre ssure ventilation. Transcutaneous oxygen saturation and PCO2, together with ECG were continuously monitored. Pulmonary artery blood flow vel ocity was measured noninvasively using pulsed wave Doppler. The 95% co nfidence intervals for the changes with and without CNEP in spontaneou sly breathing and ventilated patients showed no statistically signific ant changes in heart rate, O2 saturation, transcutaneoUS PCO2 or cardi ac output. This study shows that the use of CNEP, administered in a ta nk respirator, does not lead to large changes in cardiac output.