Tracheobronchomalacia: An Unreported Pulmonary Complication of Acute Pancreatitis

Abstract

Acute Pancreatitis(AP) is a common disease with a reported annual incidence ranging between 4.9 to 35 per 100,000 population. Multiple respiratory complications have been reported in AP including Acute Respiratory Distress Syndrome (ARDS). Here we present, to the best of our knowledge, the first reported case of Tracheobronchomalacia as a respiratory complication of AP.2900 Figure 1. CT scan showing tracheal diameter of 0.24 cm on expiration (A) and tracheal diameter of 2.9 cm on inspiration (B).A 54-year-old white male with history of Diabetes Mellitus, peripheral vascular disease (PVD) and no history of pulmonary disease was admitted for elective right Below-Knee Amputation(BKA) secondary to his PVD. Internal Medicine were asked to evaluate the patient for acute necrotizing pancreatitis (ANP) of undetermined etiology complicating his post-operative course. The patient was treated per protocol with hydration, Meropenem and pain management. Within one week of ANP onset, patient developed rapid respiratory distress. He was found to be in acute type II hypercapnic respiratory failure with PaO2/FiO2 <200. Chest radiography and arterial blood gase did not support the diagnosis of ARDS. Computed tomography (CT) with angiography ruled out pulmonary embolism but showed significant narrowing of the trachea on expiration with tracheal diameter less than 0.27 cm. When compared to a previous CT scan done 3 months earlier for a pulmonary nodule follow up, trahceal diameter was 2.8 cm. Diagnosis was confirmed by performing a dynamic CT scan with drop in tracheal diameter from 2.9 cm on inspiration to 0.24 cm on expiration (Image 1). The patient's respiratory status continued to deteriorate requiring endotracheal intubation and mechanical ventilation with weaning trials proving to be futile. The patient eventually developed Fungemia and expired after the patient's family opted for palliative extubation. Airway collapse related to Tracheobronchomalacia is an under-recognized diagnosis which should be suspected in patients with AP who develop acute respiratory distress in whom no specific etiology has been determined.