The relative efficacy of chest ultrasonography in comparison to other diagnostic modalities in the evaluation of dyspneic patient

Abstract

Background: Dyspnea is defined by the American Thoracic Society (ATS) as the subjective experience of breathing discomfort. Traditionally lung imaging in critically ill patients is performed either by bedside chest radiography (CXR) or thoracic computed tomography (CT). Nowadays bedside lung ultrasound is increasingly used for the evaluation of critically ill patients with different lung pathologies. Objective: Our study was designed to determine the relative efficacy of chest ultrasonography in comparison to CXR for the detection of four common lung pathologies (pneumothorax, pleural effusions, alveolar consolidation, and alveolar interstitial syndrome) that have important implications in dyspneic patient management and decision making using thoracic CT as a gold standard. Methods: The study was conducted on 90 adult critically ill patients of both genders who were admitted to the Department of Critical Care Medicine in The Alexandria Main University Hospital. Exclusion criteria included those who were below 18 years or above 70 years, trauma patients, any patient with moderate to severe susceptibility to have pulmonary embolism according to Wells’ Criteria and pregnant females. All patients were subjected to complete history taking, complete physical examination, complete 12-lead electrocardiogram and arterial blood gases was sampled and analyzed. Lung ultrasound, a bedside CXR and CT scan were performed in sequence in the first six hours of admission. Results: Simple bedside lung ultrasound provided immediate diagnosis of acute dyspnea in 91.1% of cases. The sensitivity, specificity, and diagnostic accuracy of CXR were 46.4, 96.8, and 81.1% for consolidation, 46.7, 98.3, and 81.1% for interstitial syndrome, 60, 100, and 97.8% for pneumothorax, and 63, 96.8, and 86.7% for pleural effusion, respectively. The corresponding values for lung ultrasound were 89.3, 100, and 96.7% for consolidation, 93.3, 100, and 97.8% for interstitial syndrome, 80, 100, and 98.9% for pneumothorax, and 92.6, 100, and 97.8% for pleural effusion, respectively. Conclusion: Lung ultrasound has a considerably better diagnostic performance than CXR for the diagnosis of common pathologic conditions and may be used as an alternative to thoracic CT.

Keywords

• Intensive care unit
• Lung ultrasonography
• Pneumothorax
• Pleural effusion
• Consolidation
• Interstitial syndrome