PS-381 Nasal High Frequency Ventilation Is Not More Effective Than Noninvasive Ventilation To Prevent Extubation Failure In Very Preterm Infants

Abstract

Background In animal models nasal high frequency oscillatory ventilation appears to provide better lung development and less injury that means it could be protective against repeated need of conventional ventilation. In a randomised study we compared the clinical efficacy of nasal high frequency oscillatory ventilation (nHFOV) and nasal intermittent positive pressure ventilation (NIPPV) in prevention of repeated intubation in preterm infants with very low birth weight. Methods 24 preterm infants with birth weight. Objective To test effects of various bypass flow rates on heart rate (HR), blood pressure (BP), cardiac output and lactate production in a piglet model. Methods Piglets (n = 10, <2 days,1.6-2.3 kg) were anaesthetized and ventilated. To achieve various high extracorporeal flow rates, the carotic artery and jugular vein were cannulated and connected to form an extracorporeal bypass. HR and BP were measured via femoral artery catheters. Cardiac output (stroke volume, minute volume) was continuously measured throughout the experiment from ECG and velocity time integral at the level of the aortic valve. Results Baseline HR of piglets (n = 10) was 190 +/- 35/min, BP:85 +/- 10/55 +/- 5(71 +/- 9) mmHg [syst./diast. (mean)], and remained stable during the ~3 h experiment, including shock index (HR/syst. BP). Cardiac output (n = 5) increased linearly via increased stroke volume from 198 mL/kg/min to 260 ml/kg/min and reflected increasing extracorporeal bypass of up to 60 mL/kg/min,. Average pH was 7.47, pCO2:40 mmHg, pO2:135 mmHg, lactate: 1.4 mmol/L. No supportive drugs for BP were needed. Conclusions Passive extracorporeal bypass required for LAD of up to 60 ml/kg min did not compromise cardiovascular parameters in newborn piglets. The results of this study support the concept of passive perfusion for the 'artificial placenta'.