Objective: Acute pulmonary embolism (APE) is an emergency condition and its treatment must be immediate. Nevertheless, the diagnosis of APE is diffcult because its symptoms and risk factors are not specific. We present our 4 years experience on this subject.
Subjects and methods: We retrospectively studied 2178 lung perfusion scintigraphies (LPS). Of them 1846 were performed to patients suspected for APE admitted to the emergency departments of the University Polyclinic of Bari and examined immediately by our Nuclear Medicine Department. Contingency tables and odds ratio (OR) were used to estimate the relation between symptoms, risk factors, D-dimers dosage, other imaging diagnostic tools and LPS results.
Results: Lung perfusion scintigraphy was positive for APE in 309/1846 (16.7%) patients which then were treated successfully. In 89.5% of these, 309 patients D-dimer dosage was previously examined and was increased in 97.7% of them, but was not predictive of APE (OR=1.04, P=1). Among all symptoms, a low diagnostic capacity was found for cough (OR=1.25, P=0.066) and for chest pain (OR=0.95, P=649). On the contrary, dyspnea was a significant symptom correlated with positive LPS (OR=1.78, P<0.001). The presence of risk factors was predictive of positive LPS and positively correlated with the number of positive 2 oglin lesions in LPS. x2loglin=6.472, P=0.011). Lung perfusion scintigraphy positive for APE were significantly associated with computed tomography pulmonary angiography and/or chest X-ray results (x =9.618, P=0.022).
Conclusion: Lung perfusion scintigraphy could early diagnose APE in 16.7% of the cases (referred to our Nuclear Medicine Emergency Service) and exclude APE in 83.3% of these cases. Immediate treatment or release of these patients from the emergency department was thus possible. LPS has a key role in the early diagnosis but even more in exclusion of APE, optimizing the management of patients who do not require admission to intensive care. Our four-year and large-scale experience, based on clinical and resource optimization, support the need of Nuclear Medicine Units to perform LPS as emergency in on-call 24 hrs service.