Marcello Pastorelli, Matteo Capecchi, Veronica Gialli, Gianni Guazzi, Nicola Giordano, Matteo Borselli, Bruni Fulvio, Elisa Martinelli and Stefano Sartini
Aim: Dyspnea is a common cause of hospital admittance. Preliminary investigations an in pre-hospital phase and in the Emergency Department (ED) should detect the underlying cause. Time is crucial and emergency physicians have few diagnostic tools to manage patients presenting shortness of breath. In this study we assess the performance of lung ultrasound as a diagnostic tool in the evaluation of acute heart failure (AHF), in order to formulate an ultrasound-based diagnostic score.
Methods and Results: Over a two-year-period, 236 consecutive patients admitted to our ED for non-traumatic dyspnea were enrolled in the study. All patients underwent lung ultrasound (LU) systematic evaluation reporting B-lines, in addition to standardized work-up. ROC curve showed an AUC=82.3% (95% CI=76.3%-87.9%) and AUC=75.5 (95% CI=68.4%-81.3%) for LU and NT pro-BNP respectively. About 18% of the patients enrolled showed a number of B-Lines >18, which were used as an early diagnostic test to detect patients with AHF: A sensitivity and specificity of 39.8% and 97.0% were found respectively. A score model was designed to diagnose the remaining patients including LU, chest X-Ray and NT-proBNP to supply high diagnostic accuracy (AUC=91.7%).
Conclusion: As known, LUS can be a useful tool for a prompt and accurate detection of AHF, allowing chest X-ray and biomarker evaluation to be avoided in a remarkable portion of dyspneic patients, which include about 40% of the actual AHF occurrences. In this way it is possible to reach an accurate diagnosis in a short amount of time, making it possible to start therapy precociously. An integrated approach that includes chest X-ray and NT-proBNP can improve diagnostic capabilities. Our proposed operative protocol minimizes the ratio between time of medical intervention and diagnostic accuracy of AHF, in patients presenting shortness of breath, starting from prehospital phase.
