A Traumatic Traveler

This patient’s complex medical history warrants a broadened differential with consideration of his cardiac history, including myocardial fibrosis and arrhythmia, and the impact of exposure to steroids on his immune and musculoskeletal systems. He has a history of atrial fibrillation, and an electrocardiogram is warranted to determine the underlying rhythm. Prolonged periods of rapid ventricular response may lead to tachycardia-induced cardiomyopathy. Myocardial fibrosis may progress despite use of angiotensin-converting enzyme inhibitors and is associated with systolic and/or diastolic dysfunction, although neither the examination findings provided nor the chest radiograph are suggestive of decompensated heart failure. Chronic exposure to corticosteroids (used in DMD to improve muscle strength and function) may predispose to numerous infectious and metabolic complications. Up to 10%-15% of patients with Pneumocystis jirovecii pneumonia may present with a normal chest radiograph. Acute adrenal insufficiency can present with tachycardia, weakness, and respiratory distress, so recent prednisone dose changes or interruptions should be assessed.

The patient’s respiratory status worsened. In light of his complex medical history, he was transferred to a children’s hospital for a higher level of care with a presumptive diagnosis of aspiration pneumonia. Upon reassessment at the new facility, the patient reported an ongoing and severe headache since his initial injury. NSAIDs had been given prior to transfer. His exam continued to be significant for tachycardia, tachypnea, and hypoxemia. His cardiac and lung examinations were otherwise normal. A comprehensive metabolic panel, procalcitonin, complete blood count with differential, and lactate were normal; his C-reactive protein (CRP) was 46.8 mg/dL (Normal <8 mg/dL). A computed tomography (CT) angiogram of the chest revealed small multifocal nodular ground-glass opacities, especially in the lower lobes, concerning for microatelectasis, multifocal pneumonia, or aspiration pneumonia. After consultation with pediatric pulmonology consultants, antimicrobials were held during the initial phase of work-up.

His headache may reflect a migraine, although further characterization and assessment for the presence and extent of head or neck trauma is warranted. Headache following trauma warrants consideration of cerebral contusion, diffuse axonal injury, intracranial hemorrhage, and carotid or vertebral artery dissection. Screening for concussion should also be performed. Hypoxemia may increase cerebral blood flow and raise intracranial pressure, resulting in headache.

CRP elevation is nonspecific and signals the presence of focal or systemic inflammation and is often elevated to a milder extent in obese patients with DMD. While normal procalcitonin argues against bacterial pneumonia, the precise level can be informative, and serial procalcitonin values may be more helpful than a single value. Although antecedent respiratory symptoms were not mentioned, viral or fungal pneumonia can present insidiously. An occult malignancy may be incidentally discovered when patients present for unrelated issues, although this and other sources of elevated CRP (eg, exacerbation of an autoimmune disease or drug reaction) remain less likely given the acuity of his presentation. Acute pulmonary embolism may be associated with a systemic inflammatory response and elevation in CRP.

In addition to the radiographic differential diagnosis already presented, the appearance of multifocal opacifications with hypoxemia raises the possibility of pulmonary infarcts or noncardiogenic pulmonary edema.