2001 OPEN FORUM Abstracts
AirwayPressure Release Ventilation (APRV) in an Infant with Chronic Lung Disease:A Case Summary.
Angela S. Mittman BS, RRT, P/P Spec., Theresa Ryan Schultz BA, RRT, RN,Lynne Crook AS, RRT, P/P Spec., Istvan Seri MD, PhD. The Children?s Hospitalof Philadelphia, Philadelphia PA
Background:Airway Pressure Release Ventilation (APRV) uses two different levels of inflatingpressure while enabling unrestricted breathing during both the inspiratory andthe expiratory phase of the mechanical breathing cycle. Previous studies inchildren and adults have found that APRV provides adequate ventilation and oxygenationat lower peak inflating pressures (PAP) than produced by Synchronized IntermittentMandatory Ventilation (SIMV), and may significantly reduce the need for relaxantsand sedatives.1,2 However, no reports are available on the use ofAPRV in neonates and young infants. Management of infants with Chronic LungDisease (CLD) and advancing postnatal age demands a constant balance betweenventilatory and sedation needs.
Case Summary:This is a former term infant with a history of left Congenital DiaphragmaticHernia (CDH), associated pulmonary hypoplasia and chronic ventilation perfusion(VQ) mismatch, as well as bronchomalacia, gastroesophogeal reflux and CLD. Herneonatal course included veno-arterial extracorporeal membrane oxygenation (ECMO),CDH repair, Nissen fundoplication, gastric tube placement, failed extubationand respiratory failure leading to tracheostomy and long-term mechanical ventilation.The infant was unable to appropriately interface with the ventilatory supportand she developed frequent asynchronous episodes resulting in hypoxemia andrespiratory acidosis. In addition to cohorting care, attempts to manage theseepisodes included comfort measures, hand ventilation, manipulations of the mechanicalventilator parameters and mode, increased dose of continuous intravenous (IV)sedation, increased frequency of rescue sedation and, finally, the additionof continuous IV neuromuscular blockade. At 5 months of age, on day 33 of positivepressure ventilation, we considered APRV as an option to improve the respiratorystatus and achieve a balance between ventilatory and sedation needs. The neuromuscularblockade was discontinued prior to changing the mode of ventilation from SIMVto APRV, and infusions of morphine and versed were maintained constant.
|Day ofventilation||Mode||ExhaledVE (cc/kg/min.)||MAP (cmH2O)||Maximum/MinimumFiO2||pH||CO2||PaO2||Sedationrescue # doses/day|
Discussion: Afterthe transition to APRV, the infant became more comfortable. IV infusions ofmorphine and versed remained constant and her need for rescue doses of sedationdecreased over the next few days. Neuromuscular blockade was never restarted.Acidosis and hypoxemia improved on APRV within two days without significantchanges in mean airway pressure (MAP), minute ventilation (VE) orFiO2. Ventilator settings remained relatively constant for 20 daysprior to beginning the weaning process. After 3 months of positive pressureventilation utilizing APRV, the patient was successfully weaned to CPAP anddischarged to home.
Conclusion: APRVprovided adequate ventilation and oxygenation without the need for additionalsedation in this infant with severe CLD.
1. Schultz, TR, CostarinoA., Durning SM, et al. Airway pressure release ventilation in pediatrics. PediatricCritical Care Medicine. 2001; 2(3).
2. Hormann C, BaumM, Putensen C, Muntz NJ, Benzer H. Biphasic positive airway pressure (BIPAP)-anew mode of ventilatory support. European Journal of Anesthesiology. 1994; 11(1):37-42.