Parameters Associated With Metabolic Response to Volume Expansion in Children Post-operative of Cardiac Surgery
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- 入组人数
- 110
- 试验地点
- 8
- 主要终点
- Area under the ROC curve (AUROC, %) of baseline Pv-aCO2/DAVO2 ratio to diagnose metabolic fluid
研究概览
简要总结
The investigators aim to validate markers of metabolic fluid-responsiveness in children with acute circulatory failure following cardiac surgery. This would allow physicians to identify which patient could benefit the most from fluid expansion, thus avoiding useless and potentially dangerous fluid expansions that could lead to fluid overload. To this end, The investigators will evaluate the diagnostic accuracy of the ratio of central venous to arterial carbon dioxide tension (Pv-aCO2) to arteriovenous oxygen content (CavO2), a simple biological marker of anaerobic metabolism, for the diagnosis of metabolic fluid responsiveness defined as a significant increase in oxygen consumption (VO2) after fluid expansion.
详细描述
Acute circulatory failure, defined as a mismatch between oxygen delivery and consumption, is a frequent but serious condition in children after cardiac surgery. Fluid expansion is the cornerstone of acute circulatory failure treatment, but several studies have highlighted the adverse effects of excessive fluid expansion. Therefore, it is crucial to assess the individual benefit-risk ratio before each fluid expansion. Currently, finding fluid responsiveness tests is a major issue in intensive care. Usually, fluid responsiveness is defined as a significant improvement in stroke volume after fluid expansion. However, this is an intermediate objective, as the ultimate goal of the treatment is to restore an adequate balance between oxygen delivery and consumption. In adults, a significant proportion of hemodynamically successful volume expansions (i.e. resulting in a significant increase in stroke volume) are in fact metabolically ineffective, as they do not result in a significant increase in VO2. Certain biological parameters indicating anaerobiosis, such as the Pv-aCO2/CavO2 ratio, could be predictive of metabolic fluid responsiveness (e.g. a significant increase in VO2) in these patients. This has never been investigated in children.
The main objective of this study will be to evaluate the diagnostic accuracy of the Pv-aCO2/DAVO2 ratio at baseline for the diagnosis of metabolic fluid responsiveness, in children hospitalized in intensive care after cardiac surgery, for whom a fluid expansion was prescribed by the physician in charge.
The investigators will conduct a non-interventional, multicentric diagnostic accuracy study in French pediatric intensive care units. VO2 will be measured at baseline (e.g. before fluid expansion) and within 1h after fluid expansion by the combination of echocardiographic assessment and both arterial and venous blood gas. Blood gas are routinely measured, in patients already implanted with arterial and central line, to help manage acute circulatory failure. Echocardiography assessment, which is noninvasive and nonradiative, is also a common practice in this situation. Additional simple demographic, hemodynamic and clinical data will be collected at baseline and within 1 hour after fluid expansion, if monitored. No supplemental blood test or invasive parameter will be collected. These data will be collected from standard monitoring and/or from the patient's medical record.
The primary outcome is the diagnostic accuracy (measured by the area under the receiver operating characteristics curve) of the index test (Pv-aCO2/DAVO2 ratio at baseline) for the diagnostic of metabolic fluid responsiveness, defined as a 15% increase in VO2 after fluid expansion compared to baseline (gold standard test).
- VO2 (ml/min/m2) will be measured as follow, at baseline and within 1h after fluid expansion: VO2=(10.CO.DAVO2)/(Body Surface Area)
- DAVO2: difference between arterial and venous oxygen content (measured by blood gas analysis)
- CO: cardiac output, measured by transthoracic echocardiography as the product of heart rate, left ventricular outflow tract surface (from a parasternal long axis view) and left ventricular outflow tract velocity-time integral (from an apical 5-chambers view).
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 0 Days 至 15 Years（Child）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Age less than or equal to 15 years old
- •Hospitalization in a pediatric intensive care unit after cardiac surgery
- •Prescription by the attending physician of a fluid expansion of 10ml/kg
- •Prescription of arterial and venous blood gas before and after the volume expansion to help manage acute circulatory failure
- •Patient implanted with a functioning arterial line
- •Patient implanted with a functioning central venous line in the superior vena cava territory
排除标准
- •Patient less than 37 weeks' corrected gestational age
- •Hemodynamic instability making the delay necessary for any test dangerous
- •Supine position contraindicated or deleterious
- •Impairment of echocardiographic acoustic window or restless patient making ultrasonography impossible
- •Opposition to participate expressed by the patient or by a parent or legal guardian
结局指标
主要结局
Area under the ROC curve (AUROC, %) of baseline Pv-aCO2/DAVO2 ratio to diagnose metabolic fluid
时间窗: at baseline
The primary outcome measure of a diagnostic accuracy study is the discriminative ability of an index test (expressed as an area under the ROC curve) to diagnose a condition (defined by a positive gold-standard reference test). In this study: * The index test is the baseline Pv-aCO2/DAVO2 ratio, i.e. the ratio between the veno-arterial carbon dioxide partial pressure gradient (mmHg) and the difference between arterial and venous oxygen content (ml.dl-1). Oxygen content and carbon dioxide partial pressure are measured by arterial and central venous blood gas analysis. * The condition is "metabolic fluid responsiveness" * The gold-standard reference test to diagnose metabolic fluid responsiveness is a VO2 increase of at least 15% between baseline and after volume expansion (i.e. ((VO2 after volume expansion - VO2 at baseline) / VO2 at baseline) \> 15%). VO2 (ml/min/m2) will be measured as follow: VO2=(10.CO.DAVO2)/(Body Surface Area), where CO (ml.min-1) is the cardiac output, measured b
次要结局
- AUROC (%) of the following index test to diagnose metabolic fluid responsiveness (same definition as above )(at baseline)
- Subgroup analysis of the primary outcome(at baseline)
- Correlation between metabolic fluid responsiveness and the following(at baseline , 28 days)