A prospective pilot and single-blind trial was conducted. A total of 89 patients with
respiratory failure admitted to the Department of
Critical Care Medicine of Anhui Provincial Hospital from September 2012 to September 2013 were enrolled. There were 32 patients with
COPD, 31 patients with cardiac
pulmonary edema, 8 patients with
interstitial lung disease, 12 with lung
infection, and 6 patients with other diseases. Another group of 30 patients without respiratory disease were enrolled as the control group. Bedside lung ultrasound examinations were performed in all patients within 24 hours, and chest radiograph was performed at the same time. The signs to be revealed were the "A" lines or horizontal lines arising from the pleural line, and the comet-tail artifact ("B" lines) arising from the lung wall interface.
RESULTS: Of 89 patients, 33 patients were shown a mean of 2.94 ± 1.87 "A" lines per case with the bedside lung ultrasound, and 38 patients with a mean of 3.27 ± 1.72 "B" lines per patient. 1.94 ± 0.96 "A" lines a case and 1.74 ± 0.82 "B" lines a case in control group. There were significant difference between the test group and control group ("A"line: t=3.835, P=0.000; "B" line: t=6.540, P=0.000). Among 32 cases with
COPD, 28 patients had a positive result of "A" line with a coincidence rate of 81.2%. In the 31 patients with cardiac
pulmonary edema, 25 patients presented "B" line, with a coincidence rate of 80.6%. The "A" lines or horizontal lines arising from the pleural line showed a sensitivity of 81.30% and a specificity of 87.70% with a positive predictive value (PPV) 78.80% and a negative predictive value (NPV) 89.30% of in the diagnosis of
COPD, and the "B" lines showed a sensitivity of 80.60% and a specificity of 77.60% with a PPV of 65.80% and a NPV of 88.20% in the diagnosis of cardiac
pulmonary edema. However, X-ray examination showed a sensitivity of 65.50%, a specificity of 86.00%, a PPV of 72.40% and a NPV of 81.70% in the diagnosis of
COPD, and it showed a sensitivity of 74.20%, a specificity of 69.00%, a PPV of 56.10% and a NPV of 83.30% in the diagnosis of cardiac
pulmonary edema. Bedside ultrasound was highly consistent with X-ray in diagnosis of
COPD [area under receiver operating characteristic curve (AUC): 0.833 vs. 0.816, P>0.05], but Kappa value of ultrasound technology "A" line in the diagnosis of
COPD was greater than the value of X-ray imaging techniques (0.685 vs. 0.527). There was little diagnostic value of ultrasound "A" line in cardiac
pulmonary edema(AUC was 0.305), while the "B" line was superior to X-ray (AUC: 0.888 vs. 0.747, P<0.001), and had a higher Kappa value than the value of X-ray imaging techniques (0.553 vs. 0.481) in cardiac
pulmonary edema.
CONCLUSIONS: