The Impact of Systemic pH on Cardiac Function and Clinical Outcome in the Critically Ill Patient
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 300
- 试验地点
- 2
- 主要终点
- Assess whether there are significant changes in CI -Cardiac index or PCCI are associated with changes in blood pH using PiCCO technology monitoring.
研究概览
简要总结
Study Title: The Impact of the pH on cardiac function in the critically ill patient Sponsor: King's College Hospital NHS Foundation Trust Chief Investigator: Dr Sancho Rodríguez-Villar IRAS Number: 227870
Hypothesis:
Titration studies in animals with normal cardiac function show that a reduction in blood pH (and presumably that of the intracellular and interstitial compartments) from the normal level of 7.40 to 7.20 is associated with a rise in cardiac output. However, when blood pH is less than 7.20, cardiac output is reduced. Similar studies in humans with or without normal cardiac function have not been done, and yet blood pH at which aggressive treatment is recommended has been set at 7.20 based solely on animal experiments. The investigators hypothesize that a change in blood pH in humans will also affect cardiac function, but the level of blood pH at which this is observed might be similar or different in humans. In addition, the presence or absence of underlying cardiac disease and the type of acid-base abnormality present might modify the response of the heart to changes in blood pH.
Primary Objectives:
- Assess whether there are significant changes in cardiac function associated with changes in blood pH.
- Relate the changes in cardiac function to the presence or absence of underlying cardiac disease.
Study Design:
A prospective multicenter observational study in 6 ICU´s (between two Trusts). During a year study period, a minimum of 300 patients will be recruited.
详细描述
Aim The aim of this study is to test the hypothesis that a change in the acidity of the blood (pH) will affect cardiac function in critically ill patients. It will also explore if the presence or absence of underlying cardiac disease and the type of pH abnormality may affect the response of the heart to changes in pH.
Justification for design Blood pH and cardiac function are monitored routinely in critically ill patients and so a prospective observational study design would be a feasible and useful method to address this question.
Inclusion/exclusion criteria explanation In intensive care practice, if a patient requires close cardiac function monitoring clinicians will use a special system for continuously monitoring the cardiac output and other heart functions to guide therapy. The system most commonly used is called PiCCO (pulse contour cardiac output).
Adult patients who are on PiCCO as part of their routine care in ICU for more than 24 hours will be eligible for inclusion in the study.
All patients who do not already have PiCCO in situ will be excluded from the study.
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
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- 未提供
排除标准
- •ALL patients WITHOUT PiCCO monitoring system AND:
- •< 18 years old
- •Vulnerable patients
- •Atrial or ventricular arrhythmia: you need a stable pulse to measure the contour.
- •Aortic, mitral or tricuspid valve insufficiency. In the case of valve insufficiency the valve does not close correctly. Therefore, the thermodilution curve is affected by indicator regurgitation, resulting in a prolonged indicator decay time.
- •Intra-Aortic Balloon pump: once again, the pulse contour is all wrong; but you can still get thermodilution cardiac output measurements.
- •Aortic aneurysm: the contour will be bizarre because the arterial compliance is going to be weird, with the aortic aneurysm acting as a damping system by absorbing all the pressure wave.
- •Extracorporeal circuit: when you are on bypass, there is no real arterial waveform
- •Pneumonectomy: PiCCO relies on there being a relatively normal pulmonary vasculature.
- •Massive pulmonary embolism: as above; it is essentially a pneumonectomy by embolism.
- •Intracardiac shunt: the PA catheter will also give an inaccurate thermodilution reading.
- •Less than a minimal tidal volume 6-8mL/kg
- •NON-positive pressure ventilated patients:
- •Why does Stroke Volume Variation only apply to positive pressure ventilated patients? It still applies in spontaneously breathing patients; however it is a poorer predictor of fluid responsiveness.
- •Why? The sensitivity is decreased: its only 63%. The spontaneous breathing efforts draw a smaller tidal volume, and from such minor changes in thoracic pressure there would insufficient change in ventricle loading; so there may still be changes to stroke volume, but they would be tiny and difficult to measure.
- •If there is profound hypovolemia, the IVC can collapse on inspiration. Obviously this decreases preload and confuses your SVV. You cannot predict fluid responsiveness this way, because you never get an accurate impression of preload.
- •In spontaneous respiration, inspiration increases the right ventricular preload, which means the right ventricular filling is likely still appeared adequate even if there is some hypovolemia. In spite of low overall volume, the right ventricular preload remains adequate, and thus at least one of the ventricles is likely to be operating in the preload-independent straight part of the Frank-Starling curve
- •Severe obesity: In obese patients, Extravascular Lung Water Index (EVLWI) is underestimated because it is related to body weight.
结局指标
主要结局
Assess whether there are significant changes in CI -Cardiac index or PCCI are associated with changes in blood pH using PiCCO technology monitoring.
时间窗: within 24 hours of being started on the PICCO monitoring system through cardiovascular monitoring study completion, an average of 5 days per patient
CI (Cardiac index or PCCI): 3-5 L/min/m2
Assess whether there are significant changes in stroke volume index associated with changes in blood pH using PiCCO technology monitoring.
时间窗: within 24 hours of being started on the PICCO monitoring system through cardiovascular monitoring study completion, an average of 5 days per patient
SVI- Stroke Volumen Index (40-60 mL/ m2)
Assess whether there are significant changes in CO-Cardiac Output or PCCO are associated with changes in blood pH using PiCCO technology monitoring.
时间窗: within 24 hours of being started on the PICCO monitoring system through cardiovascular monitoring study completion, an average of 5 days per patient
CO (Cardiac Output or PCCO): 4 - 8 L/min
次要结局
- Assess whether there are significant changes in cardiac contractility measuring the dPmx (Index of Left Ventricular Contractility) are associated with changes in blood pH using PiCCO technology monitoring.(within 24 hours of being started on the PICCO monitoring system through cardiovascular monitoring study completion, an average of 5 days per patient)
- Assess whether there are significant changes in cardiac contractility measuring the GEF (Global ejection fraction) are associated with changes in blood pH using PiCCO technology monitoring.(within 24 hours of being started on the PICCO monitoring system through cardiovascular monitoring study completion, an average of 5 days per patient)
- Assess whether there are significant changes in cardiac contractility measuring the CFI (Cardiac function index) are associated with changes in blood pH using PiCCO technology monitoring.(within 24 hours of being started on the PICCO monitoring system through cardiovascular monitoring study completion, an average of 5 days per patient)
- Assess whether there are significant changes in cardiac contractility measuring the CPI (Cardiac Power Index) are associated with changes in blood pH using PiCCO technology monitoring.(within 24 hours of being started on the PICCO monitoring system through cardiovascular monitoring study completion, an average of 5 days per patient)