Unilateral Diaphragmatic Paralysis Resulting in Pulmonary Hypertension With Cor Pulmonale and Respiratory Failure

Abstract

SESSION TITLE: Student/Resident Case Report Poster - Pulmonary Vascular Disease I SESSION TYPE: Student/Resident Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: Diaphragmatic paralysis is a condition commonly associated with trauma, neurologic compromise, or systemic disease. Unilateral diaphragmatic paralysis (UDP) uncommonly results in respiratory symptoms and is typically found incidentally on imaging. We present an unusual case of UDP causing pulmonary hypertension with cor pulmonale and respiratory failure. CASE PRESENTATION: A 67 year-old male presented to an outside facility with shortness of breath; he was found to be hypoxic to 60% for which he was intubated and thereafter transferred to our facility. His chest xray on admission indicated an elevated left hemidiaphragm with atelectasis. His renal function precluded obtaining a contrast CT scan to exclude pulmonary embolism (PE), so a bedside echocardiogram demonstrated dilation and regional wall motion abnormalities of the right ventricle concerning for sub-massive pulmonary embolism (PE). Interventional Radiology (IR) was consulted for direct thrombolysis of suspected PE but IR pulmonary angiogram found no evidence of PE. A CT Chest without contrast confirmed elevation of left hemidiaphragm with associated atelectasis of left lower lobe and rightward shift of mediastinal structures. A bubble echocardiography demonstrated no right to left shunt. Pulmonary artery catheter measured mean PA pressure of 46 (78/30), cardiac output of 6 l/min and central venous pressure of 14 cm. With no other obvious etiology of sustained respiratory failure, thoracic surgery was consulted for consideration of diaphragmatic plication. The patient underwent diaphragmatic plication with expansion of left lung, following which he was successfully weaned from mechanical ventilation in a few days. At a one month follow up, a six minute walk distance was 384 meters with a nadir of 90%. Total lung capacity was 4.56 L (70%) and DLCO was 15.3 (57%). DISCUSSION: We propose that the patient’s hypoxemic respiratory failure was due to UDP with decreased lung expansion leading to alteration of gas exchange1,2. This resulted in chronic hypoxemia that led to development of pulmonary hypertension (group 3.3) and cor pulmonale. This can occasionally lead to a right to left shunt via a patent foramen ovale, which was ruled out in our patient. Once pulmonary mechanics were improved through diaphragmatic plication, he was liberated from mechanical ventilation. CONCLUSIONS: This case underlies the importance of recognizing UDP as a cause of pulmonary hypertension and cor pulmonale resulting in acute respiratory failure. Reference #1: Elshafie, G., Acosta, J., Aliverti, A., Bradley, A., Kumar, P., Rajesh, P., & Naidu, B. (2016). Chest wall mechanics before and after diaphragm plication. J Cardiothorac Surg Journal of Cardiothoracic Surgery, 11(1). Reference #2: Freeman, R. K., Wozniak, T. C., & Fitzgerald, E. B. (2006). Functional and Physiologic Results of Video-Assisted Thoracoscopic Diaphragm Plication in Adult Patients With Unilateral Diaphragm Paralysis. The Annals of Thoracic Surgery, 81(5), 1853-1857. DISCLOSURE: The following authors have nothing to disclose: Kirill Lipatov, Tasnim Lat, Thomas Delmas, Shekhar Ghamande No Product/Research Disclosure Information