今天本來不準備寫的，因為周末一直在寫一個報告。
掃了一下閱讀器，見AJRCCM有新刊出刊（4月15日），那就看看吧。
本期中與重癥醫(yī)學有關(guān)的文獻有三篇，分別為：
第一篇：
機械通氣期間的自發(fā)呼吸早就被認為有助于氧合的改善，而氧合是治療的關(guān)鍵靶標，所以這種自主呼吸努力似乎是有益的。此外，自發(fā)呼吸更對現(xiàn)已逐漸認識到的外周肌肉和膈肌功能的廢用和喪失具有更顯著的優(yōu)勢。與之對應(yīng)。流行病學數(shù)據(jù)也表明，部分（vs.全部）支持通氣模式的使用正在增加。盡管機械通氣中自主呼吸的核心位置，但其可能導致或加重急性肺損傷的證據(jù)也在增加，特別是如果急性呼吸窘迫綜合征程度嚴重且自自主呼吸強烈者。本綜述回顧了這一現(xiàn)象的證據(jù)，探討了損傷機制，為臨床管理和未來研究提供了建議。
Spontaneous respiratory effort during mechanical ventilation has long been recognized to improve oxygenation, and because oxygenation is a key management target, such effort may seem beneficial. Also, disuse and loss of peripheral muscle and diaphragm function is increasingly recognized, and thus spontaneous breathing may confer additional advantage. Reflecting this, epidemiologic data suggest that the use of partial (vs. full) support modes of ventilation is increasing. Notwithstanding the central place of spontaneous breathing in mechanical ventilation, accumulating evidence indicates that it may cause—or worsen—acute lung injury, especially if acute respiratory distress syndrome is severe and spontaneous effort is vigorous. This Perspective reviews the evidence for this phenomenon, explores mechanisms of injury, and provides suggestions for clinical management and future research.
理由：液體反應(yīng)性評估依賴于超聲心動圖的動態(tài)參數(shù)，但其迄今尚未進行大型隊列研究進行比較。
目的：確定用于預測任何原因引起的循環(huán)衰竭的機械通氣患者的液體反應(yīng)性的動態(tài)參數(shù)的診斷準確性。
方法：在本次多中心前瞻性研究中，患者為半臥位，使用經(jīng)食管超聲測量上腔靜脈直徑（ΔSVC）的呼吸變異度，使用經(jīng)胸超聲心動圖測量的下腔靜脈直徑（ΔIVC）呼吸變異度，由兩法之一測定的左心室流出道中最大流速變異度（ΔVmaxAo）和脈壓變異度（ΔPP）。 每個患者執(zhí)行被動抬腿試驗，并以主動脈流速時間積分增加≥10％作為液體反應(yīng)性陽性。
測量和主要結(jié)果： 540例（379例男性，年齡65±13歲;簡化急性生理評分II，59±18;序貫器官功能衰竭評估，10±3），229例顯示液體反應(yīng)性陽性（42％）。 ΔPP，ΔVmaxAo，ΔSVC和ΔIVC分別為78.5％，78.0％，99.6％和78.1％的。以 ΔSVC≥21％，ΔVmaxAo≥10％，ΔIVC≥8％為反應(yīng)性陽性標準的靈敏度分別為61％的（95％置信區(qū)間，57-66％），79％ （75-83％）和55％（50-59％），特異性分別為84％（81-87％），64％（59-69％）和70％（66-75％）。 ΔSVC操作者工作特性曲線下面積明顯大于ΔIVC（ P = 0.02）和ΔPP（ P = 0.01）。
結(jié)論： ΔVmaxA具有最佳的靈敏度，ΔSVC在預測液體反應(yīng)性方面具有最佳的特異性。 ΔSVC具有比ΔIVC和ΔPP更大的診斷精度，但其測量需要經(jīng)食道超聲心動圖。
Rationale: Assessment of fluid responsiveness relies on dynamic echocardiographic parameters that have not yet been compared in large cohorts.
Objectives: To determine the diagnostic accuracy of dynamic parameters used to predict fluid responsiveness in ventilated patients with a circulatory failure of any cause.
Methods: In this multicenter prospective study, respiratory variations of superior vena cava diameter (?SVC) measured using transesophageal echocardiography, of inferior vena cava diameter (?IVC) measured using transthoracic echocardiography, of the maximal Doppler velocity in left ventricular outflow tract (?VmaxAo) measured using either approach, and pulse pressure variations (?PP) were recorded with the patient in the semirecumbent position. In each patient, a passive leg raise was performed and an increase of aortic velocity time integral greater than or equal to 10% defined fluid responsiveness.
Measurements and Main Results: Among 540 patients (379 men; age, 65±13 yr; Simplified Acute Physiological Score II, 59?±18; Sequential Organ Failure Assessment, 10±3), 229 exhibited fluid responsiveness (42%). ?PP, ?VmaxAo, ?SVC, and ?IVC could be measured in 78.5%, 78.0%, 99.6%, and 78.1% of cases, respectively. ?SVC greater than or equal to 21%, ?VmaxAo greater than or equal to 10%, and ?IVC greater than or equal to 8% had a sensitivity of 61% (95% confidence interval, 57–66%), 79% (75–83%), and 55% (50–59%), respectively, and a specificity of 84% (81–87%), 64% (59–69%), and 70% (66–75%), respectively. The area under the receiver operating characteristic curve of ?SVC was significantly greater than that of ?IVC (P＜=?0.02) and ?PP (P＜=0.01).
Conclusions: ?VmaxAo had the best sensitivity and ?SVC the best specificity in predicting fluid responsiveness. ?SVC had a greater diagnostic accuracy than ?IVC and?PP, but its measurement requires transesophageal echocardiography.
評論：乍看題目和摘要的第一句話，我們大概可以這樣說，那么這項在法國進行的研究應(yīng)該是提供了迄今為止最大型的有關(guān)機械通氣時液體反應(yīng)性指標評價的最關(guān)鍵證據(jù)之一吧！
其實不是，研究的對象限定于心衰+通氣的患者，所以，這不是一個有更高意義的研究，而且研究中的金標注是被動抬腿試驗時進行的主動脈流速時間積分增加≥10％作為液體反應(yīng)性陽性。但老實說，最后驗證的這幾個指標，ΔSVC、ΔIVC和ΔVmaxAo的敏感性與特異性都不高，拿敏感性和特異性只在80%的指標來說事有點偏低了——但這也是可以理解的，機械通氣患者的液體反應(yīng)性因正壓通氣造成的心肺交互作用加劇使其一度成為研究的熱點，但后來的臨床證實多數(shù)動態(tài)指標的敏感性/特異性不如非機械通氣患者，如果再合并心衰，其復雜機制更難以描述，因此上面稍低的敏感性與特異性還是能夠接受的。
理由：控制性機械通氣可用于急性呼吸窘迫綜合征患者的肺保護通氣。盡管具有保留膈肌運動等益處，但部分支持通氣模式因高V潮氣量和高跨肺壓可能與肺部保護通氣不相容。 作為大劑量鎮(zhèn)靜劑和控制通氣的備選方案，利用藥物解除膈肌的神經(jīng)機械偶聯(lián)或可有助于部分支持模式下的肺保護通氣。
目的：調(diào)查部分神經(jīng)肌肉阻滯是否可以促進肺部保護通氣，同時在部分通氣支持下保持膈肌活動。
方法：在本次概念驗證性研究中，10例肺損傷且Vt大于8ml/kg的患者行鎮(zhèn)靜劑壓力支持通氣（PSV）治療。在基線測量之后，行羅庫溴銨治療，在神經(jīng)調(diào)節(jié)通氣輔助（NAVA）下Vt逐漸滴定至6ml/kg的目標。隨后患者連續(xù)羅庫溴銨輸注下行PSV和NAVA通氣2小時，并測量呼吸參數(shù)，血液動力學參數(shù)和血氣值。
測量和主要結(jié)果：羅庫溴銨滴定使Vt顯著下降（平均值±SEM，9.3±0.6至5.6±0.2 ml/kg; P <0.0001），跨肺壓（26.7±2.5至10.7±1.2 cmh2o;="" p=""><0.0001），隔膜電位（17.4±2.3降至4.5±0.7μv; p=""><0.0001），并可通過連續(xù)輸注羅庫溴銨維持。在滴定過程中，ph降低（7.42±0.02至7.35±0.02; p=""><0.0001），平均動脈血壓升高（84±6至99±6 mm="" hg，="" p="0.0004），心率增加（83±7升至93±8次/分鐘;" p="">
結(jié)論：在鎮(zhèn)靜的肺損傷患者中，部分神經(jīng)肌肉阻滯在部分通氣支持期間促進肺保護通氣，同時維持膈肌電位。
Rationale: Controlled mechanical ventilation is used to deliver lung-protective ventilation in patients with acute respiratory distress syndrome. Despite recognized benefits, such as preserved diaphragm activity, partial support ventilation modes may be incompatible with lung-protective ventilation due to high Vt and high transpulmonary pressure. As an alternative to high-dose sedatives and controlled mechanical ventilation, pharmacologically induced neuromechanical uncoupling of the diaphragm should facilitate lung-protective ventilation under partial support modes.
Objectives: To investigate whether partial neuromuscular blockade can facilitate lung-protective ventilation while maintaining diaphragm activity under partial ventilatory support.
Methods: In a proof-of-concept study, we enrolled 10 patients with lung injury and a Vt greater than 8 ml/kg under pressure support ventilation (PSV) and under sedation. After baseline measurements, rocuronium administration was titrated to a target Vt of 6 ml/kg during neurally adjusted ventilatory assist (NAVA). Thereafter, patients were ventilated in PSV and NAVA under continuous rocuronium infusion for 2 hours. Respiratory parameters, hemodynamic parameters, and blood gas values were measured.
Measurements and Main Results: Rocuronium titration resulted in significant declines of Vt (mean?±?SEM, 9.3?±?0.6 to 5.6?±?0.2 ml/kg; P?
Conclusions: Partial neuromuscular blockade facilitates lung-protective ventilation during partial ventilatory support, while maintaining diaphragm activity, in sedated patients with lung injury.
好了，今天就到這里了！
