Pediatric ICU, Apollo Children's Hospital, Chennai, India.
The University of British Columbia, Vancouver, BC, Canada.
Crit Care Med. 2020 Nov;48(11):e1062-e1070. doi: 10.1097/CCM.0000000000004621.
Fluid boluses aiming to improve the cardiac output and oxygen delivery are commonly administered in children with shock. An increased mean arterial pressure in addition to resolution of tachycardia and improved peripheral perfusion are often monitored as clinical surrogates for improvement in cardiac output. The objective of our study is to describe changes in cardiac index, mean arterial pressure, and their relationship to other indices of cardiovascular performance.
The objective of our study is to describe changes in cardiac index, mean arterial pressure, and their relationship to other indices of cardiovascular performance.
DESIGN, SETTING, PATIENTS, AND INTERVENTIONS: We prospectively analyzed hemodynamic data from children in the cardiac ICU who received fluid bolus (10mL/kg of Ringers-Lactate over 30 min) for management of shock and/or hypoperfusion within 12h of cardiac surgery. Cardiac index responders and mean arterial pressure-responders were defined as CI ≥10% and mean arterial pressure ≥10%, respectively. We evaluated the gradient for venous-return (mean systemic filling pressure-central venous pressure), arterial load properties (systemic vascular resistance index and elastance index) and changes in vasopressor support after fluid bolus.
Fifty-seven children between 1 month and 16 years (median Risk adjustment after congenital heart surgery Model for Outcome Surveillance in Australia and New Zealand score of 3.8 (interquartile range 3.7-4.6) received fluid bolus. Cardiac index-responsiveness and mean arterial pressure-responsiveness rates were 33% and 56%, respectively. No significant correlation was observed between changes in mean arterial pressure and cardiac index (r = 0.035, p = 0.79). Although the mean systemic filling pressure - central venous pressure and the number of cardiac index-responders after fluid bolus were similar, the arterial load parameters did not change in mean arterial pressure-nonresponders. Forty-three patients (75%) had a change in Vasoactive-Inotrope Score after the fluid bolus, of whom 60% received higher level of vasoactive support.
The mean arterial pressure response to fluid bolus in cardiac ICU patients was unpredictable with a poor relationship between cardiac index-responsiveness and mean arterial pressure-responsiveness. Because arterial hypotension is frequently a trigger for administering fluids and changes in blood pressure are commonly used for tracking changes in cardiac output, we suggest a cautious and individualized approach to repeat fluid bolus based solely on lack of mean arterial pressure response to the initial fluid, since the implications include decreased arterial tone even if the cardiac index increases.
在休克患儿中，常给予液体冲击以改善心输出量和氧输送。通常监测平均动脉压增加以及心动过速缓解和外周灌注改善作为心输出量改善的临床替代指标。我们研究的目的是描述心指数、平均动脉压的变化及其与心血管功能其他指标的关系。
我们研究的目的是描述心指数、平均动脉压的变化及其与心血管功能其他指标的关系。
设计、地点、患者和干预措施：我们前瞻性分析了心脏重症监护病房内接受液体冲击（30 分钟内给予 10ml/kg 林格氏乳酸）以治疗心脏手术后 12 小时内休克和/或低灌注的患儿的血流动力学数据。心指数反应者和平均动脉压反应者定义为 CI≥10%和平均动脉压≥10%。我们评估了静脉回流梯度（平均全身充盈压-中心静脉压）、动脉负荷特性（全身血管阻力指数和弹性指数）以及液体冲击后血管加压支持的变化。
57 名 1 个月至 16 岁的儿童（中位澳大利亚和新西兰先天性心脏病手术后风险调整结果监测模型评分 3.8（四分位距 3.7-4.6）接受了液体冲击。心指数反应率和平均动脉压反应率分别为 33%和 56%。平均动脉压和心指数的变化之间无显著相关性（r=0.035，p=0.79）。尽管液体冲击后平均全身充盈压-中心静脉压和心指数反应者的数量相似，但平均动脉压无反应者的动脉负荷参数没有变化。43 名患者（75%）在液体冲击后血管活性-正性肌力评分发生变化，其中 60%接受了更高水平的血管活性支持。
心脏重症监护病房患者对液体冲击的平均动脉压反应不可预测，心指数反应性和平均动脉压反应性之间的关系较差。由于动脉低血压通常是给予液体的触发因素，并且血压变化通常用于跟踪心输出量的变化，因此我们建议在仅基于初始液体对平均动脉压反应缺乏的情况下，谨慎地个体化地重复液体冲击，因为即使心指数增加，也可能导致动脉张力降低。
