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Airway pressure release ventilation improves pulmonary blood flow in infants after cardiac surgery

Mark A Walsh1, Michele Merat, Gustavo La Rotta

  • 1Division of Cardiology, The Hospital for Sick Children and The University of Toronto, Toronto, Canada.

Critical Care Medicine
|July 19, 2011
PubMed

Insights

Spontaneous breathing during airway pressure release ventilation significantly increased lung perfusion in children after tetralogy of Fallot repair and cavopulmonary shunt surgery. This finding highlights improved cardiopulmonary interactions for enhanced patient recovery.

Area of Science:

  • Pediatric Cardiology
  • Cardiothoracic Surgery
  • Respiratory Physiology

Background:

  • Congenital heart defects like tetralogy of Fallot and conditions requiring cavopulmonary shunts often lead to impaired pulmonary blood flow.
  • Positive pressure ventilation strategies can influence hemodynamics and lung perfusion in critically ill children.
  • Understanding the impact of spontaneous respiratory effort during mechanical ventilation is crucial for optimizing outcomes in these vulnerable patients.

Purpose of the Study:

  • To investigate the effect of spontaneous inspiratory effort during airway pressure release ventilation on lung perfusion in pediatric patients post-cardiac surgery.
  • To compare lung perfusion and hemodynamic parameters between airway pressure release ventilation and pressure control ventilation with spontaneous ventilation.
  • To determine if transient decreases in intrapleural pressure due to spontaneous effort enhance lung perfusion.

Main Methods:

  • Prospective crossover cohort study conducted in a pediatric cardiac intensive care unit.
  • Patients included children recovering from tetralogy of Fallot repair, cavopulmonary shunt, or Fontan operation.
  • Lung perfusion, cardiac output, and oxygen consumption were measured using the Fick equation and mass spectrometry during different ventilation modes with and without spontaneous breathing.

Main Results:

  • In the presence of spontaneous ventilation, mean pulmonary blood flow increased significantly (p = .02) in all patients.
  • Oxygen delivery showed a positive trend in both tetralogy of Fallot and cavopulmonary shunt groups with spontaneous ventilation.
  • No significant differences in lung perfusion or hemodynamics were observed in the absence of spontaneous ventilation.

Conclusions:

  • Airway pressure release ventilation with spontaneous effort improves lung perfusion compared to pressure control ventilation in children after tetralogy of Fallot repair and cavopulmonary shunt operations.
  • Enhanced cardiopulmonary interactions observed in this study may offer benefits in other clinical scenarios with impaired hemodynamics.
  • The findings suggest that encouraging spontaneous respiratory effort during mechanical ventilation can be a valuable strategy in pediatric cardiac intensive care.
Abstract

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