Winning Abstracts from the 2013 Medical Student Abstract Competition: Successful treatment of Pulmonary Alveolar Proteinosis with Selective Brain Hypothermia during Whole Lung Lavage
Author: Sebastian Muñoz, MS, University of Sonora, Class of 2014
Introduction: Pulmonary alveolar proteinosis (PAP) is a rare disorder characterized by the accumulation of surfactant lipids and protein in the alveolar spaces, with resultant impairment in gas exchange. The only known treatment is whole lung lavage (WLL), which is an instillation of normal saline solution to the lung to drain proteinaceous material.
Selective brain hypothermia (SBH) is experimentally used as a method to prevent the onset of neurological injuries due to reduced oxygen to the brain. To date, this is the first case of SBH during a bilateral WLL in a patient who suffers of PAP.
Case Presentation: A 46 year-old man with PAP for six years and chronic, life-threatening, hypoxemia was admitted to our intensive care unit for management of his respiratory failure. His physical examination revealed bilateral crackles and a significant spO2 of 78 % on room air. Once admitted, a chest CT scan revealed extensive and bilateral ground glass opacities with prominent interstitial markings, consistent with PAP. Bronchoscopy revealed whitish plaques on bilateral bronchi stems, and lung biopsies confirmed the diagnosis.
WLL was considered, however, our patient was not a candidate for such procedure, due to his severe hypoxemia and the concern of neurological damage as this therapeutic intervention was being conceived. Given this grim scenario, a decision was made to experimentally undertake WLL with SBH. From an ethical viewpoint, it was felt that the probable benefit of the successful lavage with SBH outweighed the risks of respiratory failure and cardio-pulmonary arrest. The patient gave informed consent.
The procedure was initiated under general anesthesia with dual lung ventilation. Initial spO2 was 70% and increased to 82% after endotracheal intubation in the operating room. A Life-Core Sandhu cervical collarâ„¢, allowed for non-invasive induction of brain hypothermia, was placed. Ear temperature was 34.1 to 35.8 degrees Celsius during the procedure. The left lung was the first to be instilled, receiving 20 liters of normal saline. The right lung required 24 L of fluid until clear. The patient remained in the operating room for over 14 hours. The operatory blood gases revealed a pH of 7.01, a pCO2 of 68.6 and a pO2 of 50. Bilateral pleural effusions were reported as complications. Two days after the procedure the patient was extubated to a nasal cannula, fully awake, alert and oriented with improved respiratory symptoms. His neurological exam was completely normal. On six months follow up the patient has not required supplemental oxygen and has no neurological deficits.
Discussion: This case depicts the experimental use of SBH in a patient with high risk of brain injury with excellent results. Although PAP is a rare disease, further studies are required to implement this therapeutic intervention in similar conditions.