C80-07 Correcting Refractory Hypoxemia With Lobectomy - A Case of Intrapulmonary Shunting Through a Tumor

Abstract Introduction Refractory hypoxemia is a life-threatening condition and remains a diagnostic challenge for clinicians. Intrapulmonary shunting is a common etiology of persistent hypoxemia. Various pathologic processes can lead to an intrapulmonary shunt. We report a case of papillary adenocarcinoma causing intrapulmonary shunting and demonstrate reversal of hypoxemia via lung resection. Case Presentation A 72-year-old male with history of former tobacco use presented to the hospital with acute hypoxemic respiratory failure. CT of the chest was notable for a right lower lobe consolidation with scattered nodular and ground glass opacities in the right middle lobe (figure 1). The patient was initially treated for community acquired pneumonia and discharged home in stable condition. Notable hypoxemia at a pulmonary office visit one month later prompted another CT chest which showed progressive changes in the right lower lobe lesion. An infectious evaluation was negative and the patient was scheduled for an endobronchial ultrasound with biopsy for definitive diagnosis. Post-procedurally, the patient was admitted to the hospital for observation in the setting of persistent hypoxemia. Initial biopsy results were negative for malignancy, but the patient remained profoundly hypoxemic and unable to be weaned off high flow nasal cannula. An intracardiac shunt was ruled out via echocardiogram. Therefore, it was presumed that an intrapulmonary shunt was the cause of the patient’s hypoxemia. Image guided percutaneous lymph node biopsy was pursued for additional tissue and yielded papillary adenocarcinoma of the lung. After discussion with medical oncology, radiation oncology, and cardiothoracic surgery, a right lower lobectomy was performed which resulted in significant improvement in the patient’s hypoxemia. Ultimately, the patient was weaned to low flow nasal cannula and discharged on home oxygen. Final pathology from the lobectomy revealed moderately differentiated adenocarcinoma of papillary predominance. Discussion This case illustrates that patients with underlying lung malignancy can experience significant hypoxemia due to intrapulmonary shunting through the tumor. Proposed mechanisms of the shunt include increased vascularity of malignant lesions versus increased intrapulmonary pressure due to tumor burden. Lobectomy proved to be successful in managing our patient’s hypoxemia. While it may be assumed that severe hypoxemia is a barrier to surgery, our case demonstrates that surgery can in fact be the appropriate treatment for refractory hypoxemia. Lobectomy should be considered in patients with persistent hypoxemia who are thought to have intrapulmonary shunting due to a tumor. This abstract is funded by: none