新生儿肺部超声在早产儿肺部感染评价中的价值

目的 探讨新生儿肺部超声在早产儿肺部感染评价中的价值。 方法 选取肺部感染早产儿80例为观察组，无肺部感染的早产儿80例为对照组，均给予新生儿肺部超声检查，比较2组肺部超声评分、氧合指数、呼吸指数，比较观察组不同病情、预后患儿肺部超声评分、氧合指数、呼吸指数,分析肺部超声评分和氧合指数、呼吸指数的相关性。 结果 观察组肺部超声评分、氧合指数低于对照组，呼吸指数高于对照组，差异有统计学意义（P＜0.05）。观察组极危重患儿肺部超声评分、氧合指数低于危重和非危重患儿，呼吸指数高于危重和非危重患儿，危重患儿肺部超声评分、氧合指数低于非危重患儿，呼吸指数高于非危重患儿，差异有统计学意义（P＜0.05）。肺部超声评分与呼吸指数呈负相关（r=-0.455，P＜0.05），与氧合指数呈正相关（r=0.470，P＜0.05）。观察组死亡患儿肺部超声评分、氧合指数低于存活患儿，呼吸指数高于存活患儿，差异有统计学意义（P＜0.05）。肺部超声评分预测患儿预后的ROC曲线下面积为0.874，高于呼吸指数和氧合指数（P＜0.05），其截断值为20分时，敏感度和特异度为88.50%和75.00%。 结论 新生儿肺部超声在早产儿肺部感染评价中有较好的效果，值得临床使用。     

Impact and Predictors of Noncircular Left Ventricular Outflow Tract Shapes on Estimating Aortic Stenosis Severity by Means of Continuity Equations

Determining aortic stenosis (AS) severity is clinically important. Calculating aortic valve (AV) area by means of the continuity equation assumes a circular left ventricular outflow tract (LVOT). The full impact of this assumption in calculating AV area is unknown. Predictors of noncircular LVOT shape in patients with AS are undefined.In 109 adult patients with AS who underwent multiplanar transesophageal echocardiography, we calculated AV area by means of the standard continuity method and by a modified method involving planimetric LVOT area.We found 54 circular, 37 horizontal-oval, 8 vertical-oval, and 10 irregular LVOTs. Area derived by direct planimetry correlated better with the modified than the standard continuity method (r=0.89 vs r=0.85; both P=0.0001). Valve areas of patients with mild, moderate, or severe AS by planimetry were more often mischaracterized with use of the standard than modified method (29 vs 18; P <0.0001). Horizontal-oval AV area derived by planimetry (1.28 ± 0.55 cm²) was underestimated by the standard method (1.05 ± 0.47 cm²; P=0.001), but not by the modified method. Congenital AV morphology and low cardiac index were the only multivariate predictors of horizontal-oval shape. Low cardiac index was the only predictor of noncircular shape.More than half our patients with AS had noncircular LVOTs. Using the modified method reduces mischaracterizations of AS severity. Congenital AV morphology and low cardiac index predict horizontal-oval or noncircular shape. These data suggest the value of direct LVOT measurement to calculate AS severity in patients who have congenital AV or a low cardiac index.