目的：通过对老年急性呼吸困难患者肺脏B线出现情况的观察，探讨床旁肺超声在快速鉴别诊断老年人心源性呼吸困难方面的价值。方法：选取因急性呼吸困难入院的老年患者84例，于入院后治疗前行床旁肺超声检查（测量B线总数）、心脏超声检查（测量LVEF、E/E’），根据临床诊断分为急性左心衰呼吸困难组（Ⅰ组）和肺源性呼吸困难组（Ⅱ组）。分析两组之间B线总数、LVEF、E/E’及NT-proBNP有无差异，并分析B线总数与NT-proBNP，LVEF，E/E’是否相关。绘制ROC曲线，确定曲线下面积（AUC），判断NT-proBNP及B线的诊断价值，并判定B线诊断心源性呼吸困难的最佳阈值。结果：Ⅰ组患者B线总数、E/E’值、NT-proBNP值均高于Ⅱ组，EF值低于Ⅱ组，差异有统计学意义（P<0.05）。B线总数与NT-proBNP值（r=0.850，P＜0.05）、E/E’（r=0.639，P＜0.05）及LVEF（r=-0.760，P＜0.05）均有相关性。NT-proBNP及B线的AUC及95％CI分别为0.968（0.937～0.998）、0.933（0.884～0.981），以B线总数>8条诊断心源性呼吸困难的敏感性为81%，特异性为88%。结论：B线可以辅助临床鉴别诊断老年人急性左心衰，其对老年人心源性与肺源性呼吸困难的鉴别有较高的敏感性和特异性。

 Objective: To observe the emergence of cases with B-line in elderly patients with acute dyspnea, explore the value of the bedside lung ultrasound in the rapid differential diagnosis of senile acute cardiac dyspnea. Methods: Eighty-four elderly patients hospitalized with acute dyspnea, who underwent lung ultrasound(measure B-lines) and echocardiography(measure LVEF and E/E’) before pharmacotherapy were enrolled. The patients were divided into acute left ventricular failure dyspnea group(group Ⅰ) and pulmonary dyspnea group(group Ⅱ) according to the clinical diagnosis. The difference of B-lines, LVEF and E/E’ between the two groups was analyzed, and the relevance of B-lines and NT-proBNP, LVEF, E/E’ was also analyzed. Draw ROC curve, determine the area under the curve(AUC) and determine the diagnostic value of NT-proBNP, B-line. Determine the optimal threshold of the B-line diagnosing acute cardiac dyspnea. Results: B-lines, E/E’ and NT-proBNP of group Ⅰ are higher than group Ⅱ, and EF is lower than group Ⅱ. The difference is statistically significant(P<0.05). The B-line with NT-proBNP(r=0.850, P<0.05), E/E’(r=0.639, P<0.05) and LVEF(r=-0.760, P<0.05) are significantly correlated. NT-proBNP and B-line of AUC and 95% CI are 0.933(0.884～0.981), 0.968(0.937～0.998). When the B-lines is more than 8, diagnostic sensitivity of acute cardiac dyspnea achieves 81%, the specificity achieves 88%. Conclusion: The B-line may assist in clinically diagnosing elderly patients with acute left ventricular failure. The B-lines has high sensitivity and specificity in differentiated diagnosing elderly patients with acute left heart failure and pulmonary dyspnea.