Lung Ultrasound Is Accurate for the Diagnosis of High-Altitude Pulmonary Edema: A Prospective Study

Abstract

Objective The aim of this study was to assess the diagnostic accuracy of lung ultrasonography (LUS) for high-altitude pulmonary edema (HAPE). Background LUS has proven to be a reliable tool for the diagnosis of pulmonary diseases, including pneumonia, acute respiratory distress syndrome (ARDS), and pneumothorax. LUS also has potential for the diagnosis of HAPE. However, the actual diagnostic value of LUS for HAPE is still unknown. Our objective was to determine the feasibility of using LUS for the diagnosis of HAPE. Materials and Methods A prospective clinical research study of adult HAPE patients was conducted. LUS and chest X-ray (CXR) were performed in patients with suspected HAPE before and after treatment, and pulmonary moist rales were recorded concurrently. The diagnostic value of LUS, CXR, and moist rales for HAPE (i.e., their sensitivity, specificity, and positive and negative predictive values) were assessed, and the results were compared. The gold standard was the final diagnosis. Results In total, 148 patients were enrolled in the study, 126 of which were diagnosed with HAPE (85.14%). Before treatment, the diagnostic accuracy of LUS for HAPE was as follows: sensitivity, 98.41% (95% confidence interval (CI) 100.60–96.23%); specificity, 90.91% (95% CI 102.92–78.90%). LUS had higher sensitivity (0.98 vs. 0.81, P < 0.01 using the McNemar test) than moist rales for the diagnosis of HAPE. LUS also had higher sensitivity than CXR (0.98 vs. 0.93, P < 0.05 using the McNemar test). After treatment, LUS was consistent with CXR in 96.55% of HAPE patients, and the concordance between LUS and CXR was high (k statistic = 0.483 P ≤ 0.001; 95% CI −0.021 to −0.853). Conclusion The results indicate that LUS is a reliable method for the diagnosis and surveillance of HAPE. This trial is registered with Chinese Clinical Trial Registry (No. ChiCTR-DDD-16009841).

Should the ultrasound probe replace your stethoscope? A SICS-I sub-study comparing lung ultrasound and pulmonary auscultation in the critically ill

“…Chest X-ray and CT are other diagnostic methods that are frequently used for the assessment of pulmonary edema. However, previous studies have suggested that LUS is superior to chest X-ray and comparable to chest CT scan for diagnosing pulmonary edema [3,8]. Therefore, we decided not to use these modalities as a reference standard and only included a sensitivity analysis of chest X-ray.…”

“…An increasing body of evidence supports the use of LUS in diagnosing pulmonary edema and/or pneumonia [5]. Several studies have shown the diagnostic value of LUS in patients with dyspnea or specific diagnoses, such as pneumothorax, high-altitude pulmonary edema, and cardiogenic pulmonary edema [6][7][8][9][10]. LUS has even been suggested to be superior to chest radiography (X-ray) and comparable to chest computed tomography (CT) scan for the diagnosis of pulmonary edema and increased alveolar fluid (commonly referred to as interstitial syndrome) [3,8].…”

“…Several studies have shown the diagnostic value of LUS in patients with dyspnea or specific diagnoses, such as pneumothorax, high-altitude pulmonary edema, and cardiogenic pulmonary edema [6][7][8][9][10]. LUS has even been suggested to be superior to chest radiography (X-ray) and comparable to chest computed tomography (CT) scan for the diagnosis of pulmonary edema and increased alveolar fluid (commonly referred to as interstitial syndrome) [3,8]. However, few studies have compared LUS to pulmonary auscultation, even while the stethoscope still constitutes the majority of contemporary practice [11][12][13].…”

Extravascular lung water and cardiac function assessed by echocardiography in healthy lowlanders during repeated very high-altitude exposure

“…EVLW can be assessed by lung ultrasonography, in which it manifests itself as "B-lines", formerly known as "lung comets" [11], first described in patients with pulmonary edema in intensive care units [12][13][14]. In recent times, lung ultrasonography has been increasingly used to assess the development of pulmonary edema at HA, and there is an increasing body of evidence showing that the number of Blines increase during acute exposure to HA [4,5,[15][16][17][18].…”

Swimming-Induced Pulmonary Edema

“…Correlation between SpO 2 and LUS-verified pulmonary edema has been described in high-altitude edema. 23 "Checkpoint" levels of 90% and 92% for clinical diagnosis of SIPE have previously been suggested. 6,10 Based on our data, choosing a cutoff level below 95% will result in a loss of sensitivity for SIPE diagnosis.…”