Pulmonary emboli are potentially life threatening events frequently considered in patients with pulmonary complaints. The diagnosis is more likely to be missed when another obvious pulmonary pathology can explain the same complaints. A 54 year old male without any significant past medical history presented to the emergency department with 1 week of malaise, nonproductive cough and 2 days of dyspnea. At presentation he endorsed pleuritic chest pain and headaches. He had smoked half a pack per day until the week prior. He was afebrile, slightly tachycardic and profoundly hypoxic requiring 15 liters on a nonrebreather. His physical exam was unremarkable and chest xray showed a left lower lobe infiltrate consistent with a bronchial pneumonia vs aspiration. Labs showed a mild leukocytosis and transaminitis. He was admitted and started on community acquired pneumonia treatment with ceftriaxone and azithromycin with the addition of tamiflu since he had not received a flu shot that year. On hospital day 4 he had not had significant improvement and infectious labs including a flu PCR were negative so he underwent a noncontrasted CT scan that showed extensive inflammatory bronchiolitis that favored a viral or atypical pneumonia. On hospital day 7 because of persistent hypoxia and other negative work-up he underwent CT-chest angiogram which revealed multiple segmental pulmonary emboli in his right lower lobe. He had been onprophylactic anticoagulation per protocol since hospital admission. Several days later his mycoplasma IgG and IgM both came back positive. He was already being treated with azithromycin and a high dose prednisone taper was added per Pulmonary recommendations. He required a total of 16 days in the hospital primarily because of his high oxygen requirement and when discharged he was still requiring 4 L of oxygen. He was discharged on coumadin, a lovenox bridge and prednisone. This case is particularly important because we frequently use the risk stratification model to determine whether a patient should undergo work-up for pulmonary emboli and one question in that model is whether another diagnosis can better explain the patients symptoms. In this case the patient did not have any risk factors for pulmonary emboli and had evidence of infection that could explain his symptoms. Another important point this case illustrates is that mycoplasma bronchiolitis in particular, and any inflammatory process in general, may cause a hypercoagulable state raising the possibility of pulmonary emboli. While risk stratification is an important clinical tool, clinical judgment must be used to recognize when a patient is not responding as expected to clinical treatments thus prompting reconsideration of the initial diagnosis.'
Seiler, Mary and Jennifer Jernigan. "Clinical vignette: Mycoplasma pneumonia: A novel risk factor for thromboemboli?." (2014). https://digitalrepository.unm.edu/hostpitalmed_pubs/42