Division of Pulmonary Critical Care and Sleep Medicine, St. Luke's and Roosevelt Hospitals, Columbia University College of Physicians and Surgeons, New York, NY.
Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA.
Chest. 2012 Dec;142(6):1455-1460. doi: 10.1378/chest.11-1638.
Approximately 40% of patients in medical ICUs require mechanical ventilation (MV). Approximately 20% to 25% of these patients will encounter difficulties in discontinuing MV. Multiple studies have suggested that MV has an unloading effect on the respiratory muscles that leads to diaphragmatic atrophy and dysfunction, a process called ventilator-induced diaphragmatic dysfunction (VIDD). VIDD may be an important factor affecting when and if MV can be discontinued. A sensitive and specific diagnostic test for VIDD could provide the physician with valuable information that might influence decisions regarding extubation or tracheostomy. The purpose of this study was to quantify, using daily sonographic assessments, the rate and degree of diaphragm thinning during MV.
Seven intubated patients receiving MV during acute care were included. Using sonography, diaphragm muscle thickness was measured daily from the day of intubation until the patient underwent extubation or tracheostomy or died. We analyzed our data using standard descriptive statistics, linear regression, and mixed-model effects.
The overall rate of decrease in the diaphragm thickness of all seven patients over time averaged 6% per day of MV, which differed significantly from zero. Similarly, the diaphragm thickness decreased for each patient over time.
Sonographic assessment of the diaphragm provides noninvasive measurement of diaphragmatic thickness and the degree of diaphragm thinning in patients receiving MV. Our data show that diaphragm muscle thinning starts within 48 h after initiation of MV. However, it is unclear if diaphragmatic thinning correlates with diaphragmatic atrophy or pulmonary function. The relationship between diaphragm thinning and diaphragm strength remains to be elucidated.
约 40%的重症监护病房（ICU）中的患者需要接受机械通气（MV）。其中约 20%至 25%的患者在停止 MV 时会遇到困难。多项研究表明，MV 对呼吸肌有卸载作用，导致膈肌萎缩和功能障碍，这一过程称为呼吸机诱导的膈肌功能障碍（VIDD）。VIDD 可能是影响何时以及是否可以停止 MV 的一个重要因素。一种用于 VIDD 的敏感和特异的诊断测试可以为医生提供有价值的信息，这些信息可能会影响拔管或气管切开术的决策。本研究的目的是使用每日超声评估来量化 MV 期间膈肌变薄的速度和程度。
纳入 7 名在急性护理期间接受 MV 的气管插管患者。使用超声，从插管当天开始，每天测量膈肌肌肉厚度，直到患者拔管、行气管切开术或死亡。我们使用标准描述性统计、线性回归和混合模型效应分析我们的数据。
所有 7 名患者的膈肌厚度随时间的总体下降速度平均为 MV 每天 6%，与零有显著差异。同样，每个患者的膈肌厚度随时间也在减少。
超声评估膈肌提供了一种非侵入性的测量方法，可以测量接受 MV 的患者的膈肌厚度和膈肌变薄程度。我们的数据表明，膈肌肌肉变薄在 MV 开始后 48 小时内开始。然而，膈肌变薄是否与膈肌萎缩或肺功能相关尚不清楚。膈肌变薄与膈肌强度之间的关系仍有待阐明。
