Diagnostic Accuracy of Bedside Lung Ultrasound in Emergency Protocol for the Diagnosis of Acute Respiratory Failure

Abstract

Background: The multifactorial etiology of acute respiratory failure (ARF) often complicates diagnosis at an early stage of clinical presentation. Despite being a common life-threatening disorder, accurate and timely diagnosis is hindered by bad quality of bedside radiographs and nonavailability of immediate computed tomography imaging. This study was an attempt to evaluate the diagnostic accuracy of ultrasound in diagnosing ARF. Methods: This hospital-based cross-sectional study investigated the underlying etiological factor in 130 patients presenting with ARF and admitted to the intensive care unit. Lung ultrasound was performed according to the Bedside Lung Ultrasound in Emergency (BLUE) protocol. The diagnostic accuracy of lung ultrasound by emergency protocol was measured against each final diagnosis. Results: The mean age observed was 49.28 ± 14.9 years among the cohort. Of the 130 patients, pneumonia was the most common cause of ARF, seen in 42 patients. Breathlessness (56.15%) and fever accompanied by cough (25.38%) were the chief complaints. Diagnostic accuracy of ultrasound lung emergency protocol was 95.38% in the diagnosis of pulmonary edema, 100% for pneumothorax, 93.85% for pneumonia, 96.92% for chronic obstructive pulmonary disease, 99.23% for pulmonary thromboembolism, and 95.38% for acute respiratory distress syndrome. Conclusion: Lung ultrasound is a reliable modality that provided accurate and timely diagnosis of ARF in this study. Therefore, BLUE protocol is feasible, easily implementable in the intensive care unit, and must be scaled up in respiratory health-care settings.