Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, Paris, France.
Département de médecine, service de pneumologie, Hôpital Hôtel-Dieu du Centre Hospitalier de l'Université de Montréal (CHUM), Montréal, Québec, Canada.
Thorax. 2017 Sep;72(9):811-818. doi: 10.1136/thoraxjnl-2016-209459. Epub 2017 Mar 30.
In intensive care unit (ICU) patients, diaphragm dysfunction is associated with adverse clinical outcomes. Ultrasound measurements of diaphragm thickness, excursion (EXdi) and thickening fraction (TFdi) are putative estimators of diaphragm function, but have never been compared with phrenic nerve stimulation. Our aim was to describe the relationship between these variables and diaphragm function evaluated using the change in endotracheal pressure after phrenic nerve stimulation (Ptr,stim), and to compare their prognostic value.
Between November 2014 and June 2015, Ptr,stim and ultrasound variables were measured in mechanically ventilated patients <24 hours after intubation ('initiation of mechanical ventilation (MV)', under assist-control ventilation, ACV) and at the time of switch to pressure support ventilation ('switch to PSV'), and compared using Spearman's correlation and receiver operating characteristic curve analysis. Diaphragm dysfunction was defined as Ptr,stim <11 cm HO.
112 patients were included. At initiation of MV, Ptr,stim was not correlated to diaphragm thickness (p=0.28), EXdi (p=0.66) or TFdi (p=0.80). At switch to PSV, TFdi and EXdi were respectively very strongly and moderately correlated to Ptr,stim, (r=0.87, p<0.001 and 0.45, p=0.001), but diaphragm thickness was not (p=0.45). A TFdi <29% could reliably identify diaphragm dysfunction (sensitivity and specificity of 85% and 88%), but diaphragm thickness and EXdi could not. This value was associated with increased duration of ICU stay and MV, and mortality.
Under ACV, diaphragm thickness, EXdi and TFdi were uncorrelated to Ptr,stim. Under PSV, TFdi was strongly correlated to diaphragm strength and both were predictors of remaining length of MV and ICU and hospital death.
在重症监护病房（ICU）患者中，膈肌功能障碍与不良临床结局相关。超声测量膈肌厚度、活动度（EXdi）和增厚分数（TFdi）是膈肌功能的推测指标，但从未与膈神经刺激进行比较。我们的目的是描述这些变量与膈神经刺激后经气管内压变化（Ptr，stim）评估的膈肌功能之间的关系，并比较它们的预后价值。
在 2014 年 11 月至 2015 年 6 月期间，在机械通气患者插管后<24 小时（“开始机械通气（MV）”，辅助控制通气，ACV）和切换至压力支持通气时（“切换至 PSV”）测量 Ptr，stim 和超声变量，并使用 Spearman 相关分析和受试者工作特征曲线分析进行比较。膈肌功能障碍定义为 Ptr，stim <11cmHO。
共纳入 112 例患者。在开始 MV 时，Ptr，stim 与膈肌厚度（p=0.28）、EXdi（p=0.66）或 TFdi（p=0.80）均无相关性。在切换至 PSV 时，TFdi 和 EXdi 分别与 Ptr，stim 呈极强和中度相关（r=0.87，p<0.001 和 0.45，p=0.001），而膈肌厚度则无相关性（p=0.45）。TFdi <29%可可靠地识别膈肌功能障碍（敏感性和特异性分别为 85%和 88%），但膈肌厚度和 EXdi 则不能。该值与 ICU 停留时间和 MV 时间延长以及死亡率相关。
在 ACV 下，膈肌厚度、EXdi 和 TFdi 与 Ptr，stim 无相关性。在 PSV 下，TFdi 与膈肌强度强烈相关，两者均是 MV 和 ICU 以及住院死亡的预测因素。
