Department of Intensive Care, Leiden University Medical Center, Leiden, The Netherlands.
Anesth Analg. 2012 Oct;115(4):880-7. doi: 10.1213/ANE.0b013e31825fb01d. Epub 2012 Jul 4.
Mean systemic filling pressure (Pmsf) can be measured at the bedside with minimally invasive monitoring in ventilator-dependent patients using inspiratory hold maneuvers (Pmsf(hold)) as the zero flow intercept of cardiac output (CO) to central venous pressure (CVP) relation. We compared Pmsf(hold) with arm vascular equilibrium pressure during vascular occlusion (Pmsf(arm)) and their ability to assess systemic vascular compliance (Csys) and stressed volume by intravascular fluid administration.
In mechanically ventilated postoperative cardiac surgery patients, inspiratory holds at varying airway pressures and arm stop-flow maneuvers were performed during normovolemia and after each of 10 sequential 50-mL bolus colloid infusions. We measured CVP, Pmsf(arm), stroke volume, and CO during fluid administration steps to construct CVP to CO (cardiac function) curves and Δvolume/ΔPmsf (compliance) curves. Pmsf(hold) was measured before and after fluid administration. Stressed volume was determined by extrapolating the Pmsf-volume curve to zero pressure intercept.
Fifteen patients were included. Pmsf(hold) and Pmsf(arm) were closely correlated. Csys was linear (64.3 ± 32.7 mL · mm Hg(-1), 0.97 ± 0.49 mL · mm Hg(-1) · kg(-1) predicted body weight). Stressed volume was estimated to be 1265 ± 541 mL (28.5% ± 15% predicted total blood volume). Cardiac function curves of patients with an increase of >12% to 500 mL volume extension (volume responsive) were steep, whereas the cardiac function curves of the remaining patients were flat.
Csys, stressed volume, and cardiac function curves can be determined at the bedside and can be used to characterize patients' hemodynamic status.
在依赖呼吸机的患者中，可以使用吸气保持操作（Pmsf(hold)）通过将心输出量（CO）至中心静脉压（CVP）关系的零流量截距来测量最小侵入性监测下的平均全身充盈压（Pmsf）。我们比较了 Pmsf(hold)与血管阻塞期间手臂血管平衡压（Pmsf(arm)），以及它们通过血管内液体给药评估全身血管顺应性（Csys）和应激容量的能力。
在机械通气的心脏手术后患者中，在正常血容量和每次 10 次连续 50 毫升胶体输液后，在不同的气道压力下进行吸气保持操作和手臂停流操作。我们在液体给药步骤中测量 CVP、Pmsf(arm)、每搏量和 CO，以构建 CVP 至 CO（心功能）曲线和 Δ体积/ΔPmsf（顺应性）曲线。在液体给药前后测量 Pmsf(hold)。通过将 Pmsf-容量曲线外推至零压力截距来确定应激容量。
共纳入 15 例患者。Pmsf(hold)和 Pmsf(arm)密切相关。Csys 呈线性（64.3±32.7 mL·mm Hg(-1)，0.97±0.49 mL·mm Hg(-1)·kg(-1)预测体重）。应激容量估计为 1265±541 mL（28.5%±15%预测总血容量）。容积扩展>12%至 500 毫升（容积反应性）的患者的心脏功能曲线陡峭，而其余患者的心脏功能曲线平坦。
可以在床边确定 Csys、应激容量和心功能曲线，并用于描述患者的血流动力学状态。
