Hemodynamic effects of high frequency oscillatory ventilation with volume guarantee in a piglet model of respiratory distress syndrome.

Jagmeet Bhogal,Georg M Schmölzer,Po-Yin Cheung,Chloe Joynt,Tze-Fun Lee,Lisa K Hornberger,Anne Lee Solevåg,Megan O’Reilly,Richard Bruce Mink

doi:10.1371/journal.pone.0246996

Abstract

Respiratory failure is a common condition faced by critically ill neonates with respiratory distress syndrome (RDS). High frequency oscillatory ventilation (HFOV) is often used for neonates with refractory respiratory failure related to RDS. Volume guarantee (VG) mode has been added to some HFOV ventilators for providing consistent tidal volume. We sought to examine the impact of adding the VG mode during HFOV on systemic and cerebral hemodynamics, which has not been studied to date. A neonatal piglet model of moderate to severe RDS was induced by saline lavage. Piglets (full term, age 1-3 days, weight 1.5-2.4 kg) were randomized to have RDS induced and receive either HFOV or HFOV+VG (n = 8/group) or sham-operation (n = 6) without RDS. Cardiac function measured by a Millar® catheter placed in the left ventricle as well as systemic and carotid hemodynamic and oxygen tissue saturation parameters were collected over 240 min of ventilation. Mean airway pressure, alveolar-arterial oxygen difference and left ventricular cardiac index of piglets on HFOV vs. HFOV+VG were not significantly different during the experimental period. Right common carotid artery flow index by in-situ ultrasonic flow measurement and cerebral tissue oxygen saturation (near-infrared spectroscopy) significantly decreased in HFOV+VG at 240 min compared to HFOV (14 vs. 31 ml/kg/min, and 30% vs. 43%, respectively; p<0.05). There were no significant differences in lung, brain and heart tissue markers of oxidative stress, ischemia and inflammation. HFOV+VG compared to HFOV was associated with similar left ventricular function, however HFOV+VG had a negative effect on cerebral blood flow and oxygenation.

Highlights

Respiratory distress syndrome (RDS) is a frequent cause of respiratory failure in preterm infants [1]
Given the relative novelty of the high frequency oscillatory ventilation (HFOV)+Volume guarantee (VG) mode, in the present investigation we examined hemodynamic and pulmonary changes during ventilation by using a piglet model of RDS induced by saline lung lavage
Twenty-two newborn mixed breed piglets were obtained on the day of the experiment and were randomly assigned to HFOV, HFOV with VG (HFOV+VG), or sham-operated groups

Summary

Introduction

Respiratory distress syndrome (RDS) is a frequent cause of respiratory failure in preterm infants [1]. European Consensus Guidelines on the Management of Respiratory Distress Syndrome suggest that mechanical ventilation optimizes lung volumes by providing an even distribution of tidal volumes to minimize atelectasis and hyperinflation These goals can be achieved with either conventional mechanical ventilation (CMV) or high frequency oscillatory ventilation (HFOV) [2]. Given the potential for increased MAP to influence intrathoracic pressures, use of HFOV may result in reduced venous return, and, in so doing negatively impact cardiac output and oxygen delivery. This is a common clinical concern in the choice of HFOV over CMV [6,7,8]. Considering that many patients placed on HFOV are critically ill, understanding the full hemodynamic impact of such a ventilatory strategy is key [3]

Methods

Results

Conclusion