Lung Ultrasound to Diagnose Community-Acquired Pneumonia
Lung Ultrasound to Diagnose Community-Acquired Pneumonia
Purpose To analyse the ultrasonographic findings of community-acquired pneumonia (CAP) and its efficacy for diagnosis of CAP compared with chest X-ray (CXR).
Methods Patients who presented to the Emergency Department with suspected CAP were included in the study. Bedside ultrasonography was performed at each intercostal space in the midclavicular, anterior axillary, midaxillary and paravertebral lines. Any pulmonary consolidation, focal interstitial pattern, pleural-line abnormalities and subpleural lesions were recorded, and the numbers of subpleural lesions and intercostal spaces with pleural-line abnormalities were counted. All patients received bedside CXR and CT. Using CT scan as the gold standard, ultrasonography findings were compared between CAP group and non-CAP group, and between CAP patients with CT showing consolidation or diffuse ground-glass opacification. The sensitivity of ultrasonography was compared with CXR for the diagnosis of CAP.
Results Of 179 patients included in the study, 112 were diagnosed with CAP by CT. Patients in CAP group were more likely to have consolidation (p<0.001), focal interstitial pattern (p<0.001) and had higher number of subpleural lesions (p<0.001) and intercostal spaces with pleural-line abnormalities (p<0.001) on ultrasound than those without CAP. CAP patients whose CT showed consolidation were more likely to have consolidation (p<0.001) and had lower numbers of subpleural lesions (p<0.001) and intercostal spaces with pleural-line abnormalities (p<0.001) compared to CAP patients whose CT showed diffuse ground-glass opacification. The diagnostic sensitivity, specificity, and accuracy for ultrasonography and CXR were 94.6% versus 77.7% (p<0.001), 98.5% versus 94.0% (p=0.940) and 96.1% versus 83.8% (p<0.001), respectively.
Conclusions Lung ultrasonography has a better diagnostic sensitivity and accuracy for diagnosing CAP compared with CXR.
Community-acquired pneumonia (CAP) is a common and serious infectious disease associated with high morbidity and mortality. It is the sixth leading cause of death and the most common infectious cause of death worldwide. However, CAP is often misdiagnosed even now. Early and effective antibiotic treatment is important. An adequate treatment is thus reliant on an early diagnosis of pneumonia, yet the diagnosis is not always clear at presentation to the emergency department (ED). In a retrospective chart review of patients admitted with pneumonia, 22% of patients presented some reason for diagnostic uncertainty that could result in delayed antibiotics delivery.
The current imaging modalities used to diagnose CAP include chest X-ray (CXR) and CT. CXR is easier to perform than CT, but its diagnostic value is lower. Despite being the more sensitive tool for the diagnosis of CAP, CT is not practical for some patients who are critically ill or difficult to move due to high-level ventilatory support. Ultrasonography is a fast and non-invasive investigation being used frequently in the ED. Several studies have shown that bedside ultrasonography can help to diagnose cardiogenic pulmonary oedema, pneumothorax, pneumonia and pulmonary embolism. At present, the diagnosis of CAP via bedside ultrasonography mainly depends on detecting consolidation. However, CAP patients do not always have consolidation, but may have interstitial pneumonia or diffuse pulmonary infiltrations. Even if consolidation is not detected, other abnormalities could be found by ultrasonography, such as focal interstitial pattern, pleural-line abnormalities and subpleural lesions. In this study, we analysed the characteristic ultrasonography findings of CAP and compared the diagnostic sensitivity, specificity and accuracy of ultrasonography with CXR.
Abstract and Introduction
Abstract
Purpose To analyse the ultrasonographic findings of community-acquired pneumonia (CAP) and its efficacy for diagnosis of CAP compared with chest X-ray (CXR).
Methods Patients who presented to the Emergency Department with suspected CAP were included in the study. Bedside ultrasonography was performed at each intercostal space in the midclavicular, anterior axillary, midaxillary and paravertebral lines. Any pulmonary consolidation, focal interstitial pattern, pleural-line abnormalities and subpleural lesions were recorded, and the numbers of subpleural lesions and intercostal spaces with pleural-line abnormalities were counted. All patients received bedside CXR and CT. Using CT scan as the gold standard, ultrasonography findings were compared between CAP group and non-CAP group, and between CAP patients with CT showing consolidation or diffuse ground-glass opacification. The sensitivity of ultrasonography was compared with CXR for the diagnosis of CAP.
Results Of 179 patients included in the study, 112 were diagnosed with CAP by CT. Patients in CAP group were more likely to have consolidation (p<0.001), focal interstitial pattern (p<0.001) and had higher number of subpleural lesions (p<0.001) and intercostal spaces with pleural-line abnormalities (p<0.001) on ultrasound than those without CAP. CAP patients whose CT showed consolidation were more likely to have consolidation (p<0.001) and had lower numbers of subpleural lesions (p<0.001) and intercostal spaces with pleural-line abnormalities (p<0.001) compared to CAP patients whose CT showed diffuse ground-glass opacification. The diagnostic sensitivity, specificity, and accuracy for ultrasonography and CXR were 94.6% versus 77.7% (p<0.001), 98.5% versus 94.0% (p=0.940) and 96.1% versus 83.8% (p<0.001), respectively.
Conclusions Lung ultrasonography has a better diagnostic sensitivity and accuracy for diagnosing CAP compared with CXR.
Introduction
Community-acquired pneumonia (CAP) is a common and serious infectious disease associated with high morbidity and mortality. It is the sixth leading cause of death and the most common infectious cause of death worldwide. However, CAP is often misdiagnosed even now. Early and effective antibiotic treatment is important. An adequate treatment is thus reliant on an early diagnosis of pneumonia, yet the diagnosis is not always clear at presentation to the emergency department (ED). In a retrospective chart review of patients admitted with pneumonia, 22% of patients presented some reason for diagnostic uncertainty that could result in delayed antibiotics delivery.
The current imaging modalities used to diagnose CAP include chest X-ray (CXR) and CT. CXR is easier to perform than CT, but its diagnostic value is lower. Despite being the more sensitive tool for the diagnosis of CAP, CT is not practical for some patients who are critically ill or difficult to move due to high-level ventilatory support. Ultrasonography is a fast and non-invasive investigation being used frequently in the ED. Several studies have shown that bedside ultrasonography can help to diagnose cardiogenic pulmonary oedema, pneumothorax, pneumonia and pulmonary embolism. At present, the diagnosis of CAP via bedside ultrasonography mainly depends on detecting consolidation. However, CAP patients do not always have consolidation, but may have interstitial pneumonia or diffuse pulmonary infiltrations. Even if consolidation is not detected, other abnormalities could be found by ultrasonography, such as focal interstitial pattern, pleural-line abnormalities and subpleural lesions. In this study, we analysed the characteristic ultrasonography findings of CAP and compared the diagnostic sensitivity, specificity and accuracy of ultrasonography with CXR.
Source...