Value of bedside lung ultrasound for diagnosis of acute respiratory distress syndrome and for assess-ment of the severity / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the value of bedside lung ultrasound for diagnosis of acute re-spiratory distress syndrome ( ARDS) and for assessment of the severity. Methods Fifty patients of both se-xes suspected of having ARDS ( oxygenation index＜300 mmHg) and required lung CT tests and Pulse Indi-cator Continuous Cardiac Output because of their condition, aged 18-80 yr, were selected. At 24 h after entering ICU, chest CT, lung ultrasound and arterial blood gas analysis were performed to record Extravas-cular Lung Water Index ( EVLWI) and the number of B lines, and lung injury ultrasound score and oxygen-ation index were calculated. The patients diagnosed with ARDS by chest CT and lung ultrasound were divid-ed into 3 groups mild group ( 200 mmHg＜oxygenation index≤300 mmHg) , moderate group ( 100 mmHg＜oxygenation index≤200 mmHg) and severe group ( oxygenation index≤100 mmHg) . Kappa consistency a-nalysis was used to assess the consistency between lung ultrasound and chest CT in diagnosis of ARDS. The receiver operating characteristic curves of th number of B lines, EVLWI and lung injury ultrasound score in assessing the severity of ARDS were drawn, and the area under the curve and 95％ confidence interval ( CI) , critical value, sensitivity and specificity were calculated. Results Forty-six patients were diag-nosed as having ARDS by both chest CT and lung ultrasound. There was good consistency ( Kappa value 0. 648, P＜0. 01) between chest CT and lung ultrasound in diagnosis of ARDS. There was good consistency ( Kappa value 0. 788, P＜0. 01) between lung ultrasound and chest CT in diagnosis of pulmonary consolida-tion. Lung ultrasound and chest CT were in good agreement ( Kappa value 0. 825, P＜0. 01) with each oth-er in diagnosis of pulmonary consolidation in the posterior region. Compared with mild group, the lung inju-ry ultrasound score was significantly increased, and the number of B lines was increased in moderate group, and the lung injury ultrasound score and EVLWI were significantly increased, and the number of B lines was increased in severe group ( P＜0. 05) . Compared with moderate group, the lung injury ultrasound score and EVLWI were significantly increased, and the number of B lines was increased in severe group ( P＜0. 05) . The area under the curve ( 95％ CI ) of the number of B lines in diagnosing severe ARDS was 0. 915 ( 0. 905-0. 935 ) , and the critical value, sensitivity and specificity were 15. 5, 78. 9％ and 85. 2％, respectively. The area under the curve ( 95％ CI) of lung injury ultrasound score in diagnosing severe ARDS was 0. 856 (0. 833-0. 878), and the critical value, sensitivity and specificity were 25. 5, 73. 7％ and 82. 5％, respectively. The area under the curve (95％ CI) of EVLWI in diagnosing severe ARDS was 0. 907 ( 0. 888-0. 933) , and the critical value, sensitivity and specificity were 15. 5, 73. 7％and 92. 6％, respectively. Conclusion Lung ultrasound can be used for diagnosis of ARDS and for evalu-ation of the severity of ARDS.