Abstract Introduction Cannabis is the most commonly used drug in the US. Several case reports document incidences of pneumomediastinum, pneumothorax and bullous emphysema with marijuana smoking, but direct causality is not established for lack of larger studies. We present a case of giant bullous emphysema following marijuana use, causing near complete collapse of the right hemithorax and mediastinal shift, raising concerns about adequacy of residual lung function after bullectomy and prompting lung transplant evaluation. Case description A 52 year-old male with history of GERD, fibromyalgia and hip dysplasia presented to clinic with progressive exertional dyspnea since 4 years, without cough, wheezing or chest pain, worse in left-lateral decubitus position, associated with epigastric pain and bloating. He smoked marijuana for 6 years and reported prior cigarette use for 1 year. Vitals were stable with good oxygenation on room air. Physical exam revealed reduced right-sided chest wall movement and lung sounds with contralateral tracheal shift. Labs showed Hgb 17.2, WBC 3.5, Platelets 246, AST 155, ALT 106, bilirubin 0.9 and normal renal function. HIV/HCV were negative. CXR showed right-sided hyperlucency. CT Chest with contrast revealed large bullae comprising majority of volume of right hemithorax with leftward mediastinal shift and apical emphysematous changes in left lung. CT abdomen was normal. Pulmonary function tests showed very severe obstruction, mild restriction, marked air trapping and moderately reduced diffusion capacity (FEV1 21%, FVC 25%, RV/TLC 247%, DLCO 41%). α-1 antitrypsin test was normal. Given concerns with residual lung function, a multidisciplinary approach was sought involving thoracic surgery and lung transplant teams. Decision was made to pursue pneumonectomy with subsequent transplant evaluation as needed. He underwent thoracoscopic right upper lobe lung volume reduction with bullectomy. Pathology confirmed collapsed lung with large cavitary space consistent with bullae. Remarkably the right lung re-expanded postoperatively with X-ray confirming a small stable apical pneumothorax on day 9. Chest tube was clamped and patient discharged the next day. At follow-up, patient reported significant improvement in breathing. Tobacco/ marijuana avoidance was emphasized. Discussion Although the mechanism is unclear, the differences in inhalational methods of marijuana smoking, with longer puff volumes and breath holding times than tobacco, are speculated contributors to alveolar damage causing paraseptal or apical emphysema. Giant bullous emphysema have long asymptomatic periods with potential complication of significant lung compression and respiratory compromise needing bullectomy. Along with a high index of suspicion, we recommend pre-operative planning including transplant readiness in severe disease burden. This abstract is funded by: None
Bilagi et al. (Fri,) studied this question.