液体复苏对低血容量机械通气患者静脉压力阶差的影响

Effects of volume resuscitation on venous pressure gradient in hypovolemic patients undergoing mechanical ventilation

目的探讨低血容量并机械通气患者进行液体复苏时，中心静脉压（CVP）和髂总静脉压（IVP）形成的静脉压力阶差[D（c—i）VP]随液体复苏的变化，及其对循环血容量恢复是否有评估价值。方法30例需机械通气的低血容量成年患者，在保持相似通气条件下，首先输入250ml乳酸林格液（LR），如低血容量状态未纠正则继续输入LR，直至平均动脉压（MAP）t〉65mmHg（1mmHg=0．133kPa）、CVP≥8mmHg、脉搏有力、灌注改善（复苏终点）。测量并记录输液前、输LR250ml后10min及达复苏终点时3个时间点的心率（HR）、MAP、CVP、IVP、每搏量（sV）、胸腔总液量（TFC）、D（c—i）VP值，并分析输液前后D（c～i）VP与容量指标的相关性。结果输液前、输LR250ml后10min、复苏终点时，患者HR、MAP、CVP、IVP均无明显变化；而D（c—i）VP（mmHg）明显降低（分别为4．89±1．70、2．80±1．44、2．10±1．30），SV（m1）、TFC（m1）均明显升高（SV分别为42．0±10．5、49．0±8．3、58．0±12．1；TFC分别为30．0±9．6、38．0±8．6、43．0±11．1），各时间点两两比较差异均有统计学意义（P〈0．05或P〈0．01）。D（c—i）vP与TFC、SV呈显著负相关（n=-0．580，PI=0．004；r2=-0．462，P2=0．017）。结论低血容量机械通气患者随液体复苏进行，D（c—i）vP明显降低；并与TFC、SV有良好的负相关关系。提示D（c—i）VP的监测有助于指导低血容量并机械通气患者的液体复苏。

Objective To investigate the value of venous pressure gradient （D（c-i）VP） between central venous pressure （CVP） and iliac vein pressure （IVP） in assessing the responsiveness to volume resuscitation in hypovolemic patient undergoing mechanical ventilation. Methods Thirty hypovolemic patients undergoing mechanical ventilation, with maintenance of similar ventilation conditions, graded volume loading was performed with 250 ml Ringer lactate solution （LR） for each infusion in hypovolemic patients, until mean arterial pressure （MAP） I〉 65 mm Hg （ 1 mm Hg ： 0.133 kPa）, CVP≥8 mm Hg, strong pulse, perfusion improvement （recovery in the end） were reached. Before infusion, 10 minutes after infusion, and at the end of recovery, the heart rate （HR）, MAP, CVP, IVP, stroke volume （SV）, thoracic fluid content （TFC） and D （e-i）VP were measured and recorded, the correlations between D（c-i）VP and TFC, SV before and after infusion were analyzed. Results Before infusion, 10 minutes after infusion, and at the end of recovery, no significant difference was found in HR, MAP, CVP, and IVP,while D（e-i ）VP （ram Hg） was obviously lowered （4.89 ± 1.70, 2.80 ± 1.44, 2.10 ± 1.30, respectively）, and SV （ml） and TFC （ml） were significantly increased （SV was 42.0±10.5, 49.0±8.3, 58.0 ±12.1, respectively; TFC was 30.0±9.6, 38.0 ±8.6, 43.0 ±11.1, respectively）, with statistical differences （P〈0.05 or P〈0.01 ）. Negative correlations were found between D（c-i）VP and TFC, SV （r1=-0.580, P1=0.004; r2=-0.462, P2=0.017）. Conclusions In the course of fluid resuscitation in hypovolemic patients undergoing mechanical ventilation, the D （c-i）VP was significantly reduced with fluid resuscitation. At the same time, significant correlations between D（c-i）VP, TFC and SV were demonstrated. The measurement of D（e-i）VP could help guide fluid resuscitation in hypovolemie patients undergoing mechanical ventilation.