MIDODRINE: BREAKING NEW GROUND IN THE TREATMENT OF CHYLOTHORAX

Abstract

SESSION TITLE: Disorders of the Pleura SESSION TYPE: Fellow Case Reports PRESENTED ON: 10/21/2019 3:15 PM - 3:15 PM INTRODUCTION: Chylothorax is a rare condition associated with high morbidity and mortality when left untreated. Thoracic surgical procedures are the most common cause for traumatic chylothorax, presumably due to disruption of the thoracic duct or tears in the lymphatic tributaries. Pleural fluid triglyceride level of 110 mg/dL establishes the diagnosis of chylothorax. Most post-operative chyle leaks are low output, and have been managed with drainage for symptom relief, dietary modification and octreotide. When these measures fail, patients undergo surgical interventions. Midodrine, an α1-adrenergic agonist, causing lymphatic constriction is being explored as a novel therapeutic option for refractory chylothorax prior to surgical management. We present a patient with chylothorax after bilateral lung transplantation that was effectively managed with dietary modification, proton pump inhibitor, octreotide and midodrine. CASE PRESENTATION: 61-year-old female with past medical history of hypertension, hyperlipidemia, diabetes mellitus, chronic kidney disease, and pulmonary sarcoidosis presented to the hospital for bilateral lung transplantation. Her post-operative course was complicated with persistent exudative serosanguinous drainage from right chest tube with a triglyceride level of 143 mg/dL. She was treated with octreotide, proton pump inhibitor and midodrine 20 mg three times a day. She was given a fat-free supplement and PPN to meet protein needs. A specialty formula, Vivonex RTF, which contains minimal fat and MCT oil, was started 7 days later. Her fat intake was initially limited to 10 grams/day. Eventually, we increased intake to goal calories to prevent risk of essential fatty acid deficiency. Her chyle leak improved, and eventually her chest tube was discontinued. DISCUSSION: The management of chylothorax post-operatively is variable. The mainstay of treatment is a low-fat diet and octreotide. There are no studies evaluating the use of alpha-adrenergic agonists for the treatment of chylothorax. Alpha-agonistic activity may help decrease chyle flow, by causing smooth-muscle contraction in lymphatic vessels via alpha-1 receptor on lymphatic channels. Therefore, midodrine, an alpha-1 agonist, is being explored for use in the treatment of chylothorax. This case highlights the potential role of α1-adrenergic agonists in the management of chylothorax. CONCLUSIONS: The disruption of the chyle duct may be at multiple sites in a post-operative chyle leak, for which a systemic lymphatic constrictor may help stop the leak. Alpha-agonists may be helpful as an adjunctive medication for the treatment of chylothorax. Further studies are needed to determine the efficacy, appropriate dosage regimen and safety profile of midodrine in the treatment of chylothorax. It is readily available in oral forms and relatively inexpensive which makes it an ideal choice for widespread use for the treatment of chylothorax. Reference #1: McGrath, E. E., Blades, Z., & Anderson, P. B. (2010). Chylothorax: Aetiology, diagnosis and therapeutic options. Respiratory Medicine, 104(1), 1-8. https://doi.org/10.1016/j.rmed.2009.08.010 Reference #2: Sukumaran K. Nair, Matus Petko, Martin P. Hayward; Aetiology and management of chylothorax in adults, European Journal of Cardio-Thoracic Surgery, Volume 32, Issue 2, 1 August 2007, Pages 362–369, https://doi.org/10.1016/j.ejcts.2007.04.024 Reference #3: Liou, D., Warren, H., Maher, D., Soukiasian, H., Melo, N., Salim, A., & Ley, E. (2013). Midodrine. Chest, 144(3), 1055-1057. https://doi.org/10.1378/chest.12-3081 DISCLOSURES: No relevant relationships by Javed Iqbal, source=Web Response No relevant relationships by Joshua Lee, source=Web Response No relevant relationships by Dolly Patel, source=Web Response No relevant relationships by Marjan Rahmanian, source=Web Response No relevant relationships by Scott scheinin, source=Web Response No relevant relationships by Harish Seethamraju, source=Web Response