Vignon Philippe
Medical-Surgical Intensive Care Unit, Dupuytren Teaching Hospital, Limoges, France.
Clinical Investigation Center INSERM 1435, Dupuytren Teaching Hospital, Limoges, France.
Ann Transl Med. 2018 Sep;6(18):354. doi: 10.21037/atm.2018.05.46.
Cardiac patients are at high risk of weaning failure due to the abrupt burden to the cardiovascular system resulting from the transition from positive-pressure ventilation to spontaneous breathing. Similarly, numerous patients with borderline cardiac function, left ventricular diastolic dysfunction, chronic obstructive pulmonary disease, especially with associated fluid overload or cumulative positive fluid balance, are at high risk of weaning failure of cardiac origin. The diagnosis of weaning-induced pulmonary oedema (WiPO) relies on the measurement of elevated left ventricular filling pressure, or on the presence of a surrogate reflecting pulmonary or cardiac congestion. Plasma concentration of B-type natriuretic peptide and N-terminal proBNP, biological signs of hemoconcentration (increased circulating protein or hemoglobin levels), or measurement of extravascular pulmonary lung water using transpulmonary thermodilution have been proved valuable surrogates for the identification of weaning failure. Nevertheless, studies have not yet compared these indirect methods to precisely determine their respective diagnostic values for the identification of WiPO, especially in heart failure patients. In addition, none of these approaches directly assess left ventricular filling pressure and the mechanism of WiPO. In contrast, critical care echocardiography is ideally suited to establish the diagnosis of weaning failure of cardiac origin. It allows identifying the high-risk population, monitoring hemodynamically the patient at risk, depicting an abrupt increase of left ventricular filling pressure consistent with WiPO when the patient fails weaning, identifying the underlying mechanism of WiPO, and finally it allows tailoring the therapeutic management of the patient who failed weaning. The impact on patient-centered outcomes of such integrated management strategy based on critical care echocardiography deserves to be prospectively tested in a large population of patients at high risk of weaning failure of cardiac origin.
由于从正压通气过渡到自主呼吸会给心血管系统带来突然的负担，心脏疾病患者发生撤机失败的风险很高。同样，许多心功能临界、左心室舒张功能障碍、慢性阻塞性肺疾病的患者，尤其是伴有液体超负荷或累积正液体平衡的患者，也有很高的心脏源性撤机失败风险。撤机诱发肺水肿（WiPO）的诊断依赖于左心室充盈压升高的测量，或依赖于反映肺或心脏充血的替代指标的存在。B型利钠肽和N末端前脑钠肽的血浆浓度、血液浓缩的生物学指标（循环蛋白或血红蛋白水平升高），或使用经肺热稀释法测量血管外肺水，已被证明是识别撤机失败的有价值替代指标。然而，尚未有研究比较这些间接方法以精确确定它们在识别WiPO方面各自的诊断价值，尤其是在心力衰竭患者中。此外，这些方法均未直接评估左心室充盈压和WiPO的机制。相比之下，重症监护超声心动图非常适合用于诊断心脏源性撤机失败。它能够识别高危人群，对有风险的患者进行血流动力学监测，在患者撤机失败时描绘出与WiPO一致的左心室充盈压突然升高，识别WiPO的潜在机制，最后还能为撤机失败的患者量身定制治疗管理方案。基于重症监护超声心动图的这种综合管理策略对以患者为中心的结局的影响，值得在大量有心脏源性撤机失败高风险的患者中进行前瞻性测试。
