动态动脉弹性对感染性休克患者去甲肾上腺素减量后血压反应的预测价值

The predictive value of dynamic arterial elastance in arterial pressure response after norepinephrine dosage reduction in patients with septic shock

目的 探索动态动脉弹性（Eadyn）对感染性休克患者去甲肾上腺素减量后血压反应的预测价值.方法 采用前瞻性观察性队列研究方法,选2014年1月至2015年12月南京医科大学附属无锡市人民医院重症医学科收治的32例行机械通气且计划去甲肾上腺素减量的感染性休克患者.采用脉搏指示连续心排血量（PiCCO）监测技术记录去甲肾上腺素减量前后各项血流动力学指标,Eadyn为脉压变异度（PPV）/每搏量变异度（SVV）比值.根据去甲肾上腺素减量后平均动脉压（MAP）的变化,将患者分为MAP有反应者（MAP下降≥15％）和MAP无反应者（MAP下降＜15％）.通过AUCRoc评价Eadyn预测感染性休克患者去甲肾上腺素减量后MAP反应性的价值.结果 32例感染性休克患者中MAP有反应者13例,MAP无反应者19例,MAP有反应者的Eadyn低于MAP无反应者（0.77 ±0.13比1.09 ±0.31,P＜0.05）.去甲肾上腺素减量前后收缩压变化率、舒张压变化率、MAP变化率、体循环血管阻力变化率与减量前Eadyn呈正相关（r =0.621,P=0.000;r =0.735,P=0.000;r =0.756,P=0.000;r=0.568,P=0.000）,而每搏量变异度、减量前体循环血管阻力、去甲肾上腺素基础剂量与减量前Eadyn间无相关性（r=0.264,P=0.076;r =0.078,P=0.545;r =0.002,P=0.987）.Eadyn≤0.97预测去甲肾上腺素减量诱发MAP下降的AUCRoc为0.85,敏感性为100.0％,特异性为73.7％.结论 感染性休克患者应用去甲肾上腺素时,Eadyn能预测去甲肾上腺素减量所诱发的血压下降.

Objective To assess whether dynamic arterial elastance （Eadyn）can be used to predict the reduction of arterial pressure after decreasing norepinephrine （NE） dosage in patients with septic shock.Methods A prospective observational cohort study was conducted.Thirty-two patients with septic shock and mechanical ventilationwere enrolledfrom January 2014 to December 2015 in ICU of Wuxi People＆#39;s Hospital of Nanjing Medical University.Hemodynamic parameters were recorded by pulse contour cardiac output（PiCCO） monitoring technology before and after decreasing norepinephrine dosage.Eadyn was defined as the ratio of pulse pressure variation （PPV） to stroke volume variation （SVV）.Mean arterial pressure （MAP） variation was calculated after decreasing the dose of NE.Response was defined as a ≥ 15%decrease of MAP.AUC was plotted to assess the value of Eadyn in predicting MAP response.Results A total of 32 patients were enrolled in our study,with 13 responding to NE dose decrease where as the other 19 did not.Eadyn was lower in responders than in nonresponders （0.77 ± 0.13 vs 1.09 ± 0.31,P 〈 0.05）.Baseline Eadyn was positively correlated with systolic blood pressure variation,diastolic blood pressure variation,systemic vascular resistance variation and MAP variation （r =0.621,P =0.000;r =0.735,P =0.000;r =0.756,P =0.000;r =0.568,P =0.000 respectively）.However,stoke volume variation,baseline level of systemic vascular resistance and NE baseline dose were not correlated with Eadyn baseline value （r =0.264,P =0.076;r =0.078,P =0.545;r =0.002,P =0.987 respectively）.Eadyn ≤ 0.97 predicted a decrease of MAP when decreasing NE dose,with an area under the receiver-operating characteristic curve of 0.85.The sensitivity was 100.0% and specificity was 73.7%.Conclusions In septic shock patients treated with NE,Eadyn is an index to predict the decrease of arterial pressure in response to NE dose reduction.