From the Department of Emergency Medicine (G.V., E.B., V.S., M.F.F.) and Intensive Care Unit (G.R.), San Luigi Gonzaga University Hospital, Torino, Italy; Intensive Care Unit (S.S., E.C.) and Radiology Department (L.L.), Città della salute e della scienza, Molinette University Hospital, Torino, Italy; Department of Emergency Medicine (G.C.) and Intensive Care Unit (A.A.), Vittorio Emanuele University Hospital, Catania, Italy; and Intensive Care Unit, Maggiore della Carità University Hospital, Novara, Italy (M.T.).
Anesthesiology. 2014 Aug;121(2):320-7. doi: 10.1097/ALN.0000000000000300.
Pulmonary congestion is indicated at lung ultrasound by detection of B-lines, but correlation of these ultrasound signs with pulmonary artery occlusion pressure (PAOP) and extravascular lung water (EVLW) still remains to be further explored. The aim of the study was to assess whether B-lines, and eventually a combination with left ventricular ejection fraction (LVEF) assessment, are useful to differentiate low/high PAOP and EVLW in critically ill patients.
The authors enrolled 73 patients requiring invasive monitoring from the intensive care unit of four university-affiliated hospitals. Forty-one patients underwent PAOP measurement by pulmonary artery catheterization and 32 patients had EVLW measured by transpulmonary thermodilution method. Lung and cardiac ultrasound examinations focused to the evaluation of B-lines and gross estimation of LVEF were performed. The absence of diffuse B-lines (A-pattern) versus the pattern showing prevalent B-lines (B-pattern) and the combination with normal or impaired LVEF were correlated with cutoff levels of PAOP and EVLW.
PAOP of 18 mmHg or less was predicted by the A-pattern with 85.7% sensitivity (95% CI, 70.5 to 94.1%) and 40.0% specificity (CI, 25.4 to 56.4%), whereas EVLW 10 ml/kg or less with 81.0% sensitivity (CI, 62.6 to 91.9%) and 90.9% specificity (CI, 74.2 to 97.7%). The combination of A-pattern with normal LVEF increased sensitivity to 100% (CI, 84.5 to 100%) and specificity to 72.7% (CI, 52.0 to 87.2%) for the prediction of PAOP 18 mmHg or less.
B-lines allow good prediction of pulmonary congestion indicated by EVLW, whereas are of limited usefulness for the prediction of hemodynamic congestion indicated by PAOP. Combining B-lines with estimation of LVEF at transthoracic ultrasound may improve the prediction of PAOP.
肺部超声检测到 B 线提示肺淤血，但这些超声征象与肺动脉闭塞压（PAOP）和血管外肺水（EVLW）的相关性仍有待进一步探讨。本研究旨在评估 B 线，甚至结合左心室射血分数（LVEF）评估，是否有助于区分危重症患者的低/高 PAOP 和 EVLW。
作者纳入了来自四家大学附属医院的重症监护病房需要有创监测的 73 例患者。41 例患者行肺动脉导管法测量 PAOP，32 例患者行经肺热稀释法测量 EVLW。行肺部和心脏超声检查，重点评估 B 线和 LVEF 的大致估计。无弥漫性 B 线（A 型）与主要表现为 B 线（B 型）的模式以及正常或受损的 LVEF 相结合，与 PAOP 和 EVLW 的截断值相关。
A 型预测 PAOP 为 18mmHg 或更低，其敏感性为 85.7%（95%CI，70.5 至 94.1%），特异性为 40.0%（CI，25.4 至 56.4%），而 EVLW 为 10ml/kg 或更低，其敏感性为 81.0%（CI，62.6 至 91.9%），特异性为 90.9%（CI，74.2 至 97.7%）。A 型与正常 LVEF 相结合，预测 PAOP 为 18mmHg 或更低的敏感性增加至 100%（CI，84.5 至 100%），特异性增加至 72.7%（CI，52.0 至 87.2%）。
B 线可较好地预测 EVLW 提示的肺淤血，而对 PAOP 提示的血流动力学淤血的预测作用有限。在经胸超声检查中结合 B 线和 LVEF 估计可提高 PAOP 的预测效果。
