A 54-year-old male active smoker with a history of chronic obstructive lung disease (COPD) on 2 L/min of home oxygen and human immunodeficiency virus-1 (HIV) on antiretroviral therapy with a recent CD4 count of 482 (26%) cells/cc and a suppressed viral load, presented to the Emergency Room (ER) of University of Louisville Hospital with a cough productive of thick, yellow phlegm, dyspnea for 4 days and chest tightness for one day. He complained of having a sore throat, rhinorrhea and nasal congestion during the previous week. He had been using his inhalers at home without significant relief. He denied fever or chills. He had been to the ER multiple times with worsening dyspnea and nonproductive cough, which improved with prednisone and bronchodilators. He declined frequent admission, but this was his third visit to the ER in the last two days; each via emergency medical services transportation. In the ER, his temperature was 36.6°C, blood pressure was 210/141 mmHg, heart rate was 120 beats/min, and respiratory rate 16/min. His oxygen saturation was 98% while wearing a non-rebreather mask. On physical examination, there was no pharyngeal erythema or exudate and sinuses were nontender. He had pursed lip breathing with significant inspiratory wheezing. After administration of a breathing treatment and steroids, there was improved aeration throughout all lung fields with decreased, but still diffuse, expiratory wheezing. A chest X-ray was obtained. (Figure 1) His electrocardiography was unchanged, and troponins were negative. He was admitted to the Intensive Care Unit (ICU) for use of non-invasive ventilation. Diagnostic Approach Dr. Viswanathan Nagarajan (ID fellow): The patient's symptoms were acute in onset with shortness of breath, cough and yellow sputum production, and an episiode of chest tightness, with a history of COPD and active smoking. The differential diagnoses at this point are numerous including resipiratory viruses (e.g., influenza A and B, rhinovirus, respiratory syncytial virus (RSV)), and bacteria including Hemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis). The chest tightness which occurred suddenly with continued worsening of oxygenation could be from pneumonia, bronchitis or fatigue associated with use of accessory muscles. Although, the chest X-ray does not reveal a consolidation, I note a lack of vascular markings on the right upper part of the thorax when compared to the left side. Even though a high blood pressure and a lack of a pleural line argue against the possibility of a pneumothorax, my concern is that this patient has a pneumothorax of the right lung in view of his symptoms of acute onset of chest pressure, worsening oxygenation and tachycardia. Frequently, in small pneumothoraces, physical exam and blood pressure may be normal. After reviewing the chest X-ray, my differential diagnoses take a path towards pneumonia causing pneumothorax, rupture of a bulla from COPD, any cavity producing organism like Mycobacterium avium intracellulare or M. tuberculosis.
