Prospective study of the clinical features and outcomes of emergency department patients with delayed diagnosis of pulmonary embolism.

OBJECTIVES: The authors hypothesized that emergency department (ED) patients with a delayed diagnosis of pulmonary embolism (PE) will have a higher frequency of altered mental status, older age, comorbidity, and worsened outcomes compared with patients who have PE diagnosed by tests ordered in the ED.
METHODS: For 144 weeks, all patients with PE diagnosed by computed tomographic angiography were prospectively screened to identify ED diagnosis (testing ordered from the ED) versus delayed diagnosis (less than 48 hours postadmission). Serum troponin I level, right ventricular hypokinesis on echocardiography, and percentage pulmonary vascular occlusion were measured at diagnosis; patients were prospectively followed up for adverse events (death, intubation, or circulatory shock).
RESULTS: Among 161 patients with PE, 141 (88%) were ED diagnosed and 20 (12%) had a delayed diagnosis. Patients with a delayed diagnosis were older than ED-diagnosed patients (61 [+/-15] vs. 51 [+/-17] years; p < 0.001), had a longer median time to heparin administration (33 vs. 8 hours; p < 0.001), and had a higher frequency of altered mental status (30% vs. 8%; p = 0.01) but did not have a higher frequency of prior cardiopulmonary disease (25% vs. 23%). Patients with a delayed diagnosis had equal or worse measures of PE severity (right ventricular hypokinesis on echocardiography, 60% vs. 58%; abnormal troponin I level, 55% vs. 24%); on computed tomographic angiography, ten of 20 patients with a delayed diagnosis had PE in lobar or larger arteries and >50% vascular obstruction. Patients with a delayed diagnosis had a higher rate of in-hospital adverse events (9% vs. 30%; p = 0.01).
CONCLUSIONS: In this single-center study, the diagnosis of PE was frequently delayed and outcomes of patients with delayed diagnosis were worse than those of patients with PE diagnosed in the ED.