Introduction: Acute dyspnea is a common cause of hospitalization in emergency departments (ED).Distinguishing the cardiac causes of acute dyspnea from pulmonary ones is a major challenge for responsible physicians in EDs. This study compares the characteristics of bedside ultrasonography with serum level of blood natriuretic peptide (BNP) in this regard.
Methods: This diagnostic accuracy study compares bedside ultrasonography with serum BNP levels in differentiating cardiogenic causes of acute respiratory distress. Echocardiography was considered as the reference test. A checklist including demographic data (age and sex), vital signs, medical history, underlying diseases, serum level of BNP, as well as findings of chest radiography, chest ultrasonography, and echocardiography was filled for all patients with acute onset of dyspnea. Screening characteristics of the two studied methods were calculated and compared using SPSS software, version 20.
Results: 48 patients with acute respiratory distress were evaluated (50% female). The mean age of participants was 66.94 ± 16.33 (28-94) years. Based on the results of echocardiography and final diagnosis, the cause of dyspnea was cardiogenic in 20 (41.6%) cases. Bedside ultrasonography revealed the cardiogenic cause of acute dyspnea in 18 cases (0 false positive) and BNP in 44 cases (24 false positives). The area under the ROC curve for bedside ultrasonography and BNP for differentiating the cardiogenic cause of dyspnea were 86.4 (95% CI: 74.6-98.3) and 66.3 (95% CI: 49.8-89.2), respectively (p = 0.0021).
Conclusion: It seems that bedside ultrasonography could be considered as a helpful and accurate method in differentiating cardiogenic causes of acute dyspnea in emergency settings. Nevertheless, more study is needed to make a runaway algorithm to evaluate patients with respiratory distress using bedside ultrasonography, which leads to rapid therapeutic decisions in a short time.
Keywords: Ultrasonography; brain; dyspnea; echocardiography; emergency service; hospital; natriuretic peptide.