The Science Journal of the American Association for Respiratory Care

2011 OPEN FORUM Abstracts


Kevin J. Bullock1, Craig D. Smallwood1, Cindy Barrett2; 1Respiratory Care, Children's Hospital Boston, Boston, MA; 2Cardiology, Children's Hospital Boston, Boston, MA

Introduction: A 3 year old, 15kg patient with a primary diagnosis of double outlet right ventricle with pulmonary stenosis, underwent a Kawashima procedure and hepatic vein baffle to the pulmonary circulation. The patient suffered a cardio-pulmonary arrest and was subsequently supported for five days with ECMO. After decannulation from ECMO, the patient suffered recurrent pulmonary hemorrhages leading to altered gas exchange and the need for high ventilatory pressures. Case Summary: Due to worsening respiratory status, a bronchoscopy was performed which revealed numerous blood clots in the airways likely causing a "ball-valve" effect. Approximately six hours following the bronchoscopy the patient's ventilatory support was escalated from PCSIMV 36/6 x 20 100% to PCSIMV 42/6 x 22 100% with 6mL/kg Vt. The patient continued to demonstrate a significant respiratory acidosis (ABG 6.82/241/77/37). Support was further escalated to 46/10, the flow graphics on the ventilator were suggestive of inadequate emptying of the lungs, therefore, the rate was reduced to 16 and heliox therapy was initiated at an 80/20 helium/oxygen mixture. Upon initiation of heliox the CO2 elimination rapidly increased from 54ml/min to 162ml/min and the Vt increased to 15ml/kg. Copious amounts of thick clot were suctioned from the endotracheal tube within minutes of heliox initiation, whereas prior to heliox, minimal clot was suctioned. Within four hours the patient's ABG improved to 7.30/63/41/30 and the ventilator was weaned to 38/8 x 16 with Vt 13ml/kg. Eight hours following heliox administration the ABG was 7.36/56/47/29 and the ventilator was weaned to 36/8 x 16 with a 70/30 heliox mixture. Heliox was discontinued thirty-six hours later and the patient was successfully extubated. Discussion: Heliox therapy has been used for treatment of severe bronchoconstriction and other etiologies that cause the airways to be narrowed. Our case exemplifies the use of heliox to improve gas exchange in a patient with blood clot causing partial obstruction of small airways. Heliox allowed us to improve gas exchange by improving laminar air flow, by-passing clot and re-inflating collapsed areas of lung. Additionally, heliox appeared to help facilitate migration of clot to the upper airways for removal, possibly due to increased peak expiratory flow rates. Sponsored Research - None