A 32-year-old man presents to the emergency department with sudden-onset, right-sided chest pain and shortness of breath which began one hour ago. He denies fever but complains of palpitations and has difficulty completing sentences while talking. He was diagnosed with ankylosing spondylitis 10 years ago and is managed successfully with an anti-tumor necrosis factor (TNF) blocker as well as naproxen for joint pains. He does not smoke cigarettes or drink alcohol. Family history is significant for hypertension in his father at age 52 years and diabetes in his mother at age 46 years. Vital signs are blood pressure 110/75 mmHg, pulse rate 109 beats/min, respirations 36/min, and temperature of 37.5° C (99.5° F). Pulse oximetry shows 89% on room air. Physical examination reveals decreased breath sounds in the right upper lung field as well as hyperresonance and reduced vocal fremitus. There is no jugular venous distention. Systolic blood pressure does not fall more than 10 mmHg on inspiration. He is started on 100% oxygen.
Which of the following is the most appropriate next step in the management of this patient?
A) Bedside ultrasound of the chest
This patient has signs, symptoms, and physical findings suggestive of spontaneous pneumothorax. Chest radiography or pleural ultrasonography are appropriate modalities for diagnosis. Pleural ultrasonography is best utilized when rapid imaging is needed to make a diagnosis of pneumothorax, such as when the patient is unstable or when tension pneumothorax is suspected. This patient is unstable on the basis of respiratory rate > 24 breaths per minute, room air saturation < 90%, and inability to speak in whole sentences.
Answer choice B: Chest tube placement, is incorrect. Patients with spontaneous pneumothorax who are unstable or have tension pneumothorax should be treated with chest tube thoracostomy. However, bedside ultrasound can be performed quickly to confirm the diagnosis before a chest bue is placed.
Answer choice C: Close observation with outpatient follow-up, is incorrect. This patient is unstable and requires diagnosis of his pneumothorax followed by appropriate treatment.
Answer choice D: Computed tomography (CT) scan of the chest, is incorrect. Chest CT is more accurate than chest radiography or ultrasonography for the diagnosis of pneumothorax and is particularly helpful when diagnostic doubt exists. In this unstable patient, bedside ultrasonography would provide more prompt diagnosis.
Answer choice E: Ventilation-perfusion (V/Q) scan, is incorrect. V/Q scan is not used in the diagnosis of pneumothorax.
Key Learning Point
The choice of imaging modality for spontaneous is dependent upon the stability of the patient, the availability of bedside ultrasonography, and the degree of suspicion for other diagnoses. Unstable patients should have rapid bedside imaging with pleural ultrasonography. Stable patients can wait for chest radiography.
