The Science Journal of the American Association for Respiratory Care

2012 OPEN FORUM Abstracts


Kristen Hood1, Maria T. Zuluaga1,2; 1ChildrenÂ’s Medical Center Dallas, Dallas, TX; 2Division of Critical Care Medicine, University of Texas Southwestern, Dallas, TX

Introduction: Tracheobronchomalacia (TBM) is a condition characterized by weakness of the cartilage within the trachea and one or both mainstem bronchi. Patients with severe TBM have significant airway collapse during expiration leading to hyperinflation and inadequate ventilation and often require long term mechanical ventilation. When patients with TBM spontaneously breathe; airways collapse without transmitting changes in flow to the ventilator. This makes synchronization with the ventilator difficult. Use of airway stents has shown increased mortality and morbidity. Leaving positive pressure, control of ventilation and artificial airway insertion the only viable treatments. Case: A 3 month old male infant was admitted to our facility for surgical repair of double outlet right ventricle. Post-operative course was remarkable for multiple failed attempts to wean from non-invasive ventilation and recurrent need for intubation. Bronchoscopy revealed severe tracheomalacia and left mainstem bronchomalacia with 40% obstruction. Patient underwent tracheostomy to bypass tracheomalacia. Post operatively a large amount of intrinsic PEEP with abrupt expiratory flow termination was noted on the ventilator indicating continued airway collapse. Different sizes of tracheostomy tubes and multiple modes of ventilation were attempted without success. Only keeping PEEP at 20 cmH2O, stabilized malacia and improved ventilation, yet any attempt made by the patient to spontaneously breath or bare down resulted in recurrent severe episodes of hypoxia and hypercarbia requiring manual adjustment in PS and PEEP for recovery. Edi catheter placement revealed trigger, volume, and termination asynchrony. Patient was subsequently switched to NAVA mode with vast improvement in events and ultimate weaning of PEEP. Patient was able to receive additional support immediately without manual ventilator adjustment. Monitoring of Edi signal during PSCPAP assisted in determining level of patient work as well as adequate PEEP and PS settings. Patient was successfully transitioned to the Trilogy ventilator with sprints monitored by Edi values. Discussion: NAVA has been shown to reduce trigger delay and improve ventilator response time in several pediatric and neonatal studies. However in this case NAVA relieved asynchrony and provided appropriate support by adjusting off of the electrical activity of the diaphragm. NAVA is not limited by clinician derived flow, volume, or pressure settings. Sponsored Research - None Patient trend data illustrating multiple collapse events characterized by decreased pulmonary compliance necessitating increased PIP