Occlusion Pressure at 100 Msec, TCe ( Expiratory Time Constant ), Stress Energy Density, Mechanical Power, Ventilatory Ratio and C20/Cdyn in Predicting Outcomes in Patients With Moderately Severe ARDS, Who Are on Mechanical Ventilation
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- CentraCare
- 入组人数
- 50
- 试验地点
- 1
- 主要终点
- Survival or mortality
研究概览
简要总结
This is a single-centre prospective observational study aimed to determine if Pocc (occlusion pressure at 100 msec), TCe ( Expiratory time constant ), Mechanical Stress power, Ventilatory ratio and C20/Cdyn would predict outcomes in patients with moderately severe ARDS (Acute respiratory distress syndrome), who are on mechanical ventilation
详细描述
Severe ARDS is characterized by significant lung heterogeneity with areas of collapse, consolidation and normal lung parenchyma. Institution of mechanical ventilation may result in Ventilation-induced lung injury because of significant heterogeneity with associated volutrauma, atelectrauma and barotrauma.
Underassistance results in persistent atelectasis and resultant diffusion abnormalities and over-assistance causes ventilator-associated lung injury.
Mechanical power and driving pressure have been demonstrated to predict mortality in patients with Acute respiratory distress syndrome who are on mechanical ventilators. Mechanical work is the energy delivered to the respiratory system during a single inspiratory cycle and is calculated by solving the integral of airway pressure to change in volume. Mechanical power is work multiplied by RR(Respiratory rate). In the clinical setting, various equations have been used to calculate mechanical power. Mechanical Stress is defined as the internal distribution of force per unit area to an external load and associated deformation has been referred to as Strain. Stress is derived from specific lung elastance. Mechanical stress power is the power associated with internal forces required to maintain internal stresses within an object and is a part of mechanical power that is not converted to kinetic energy but rather into heat and change in internal energy.
The time constant is a measure of respiratory mechanics and is calculated by the product of compliance and resistance. Theoretically, it is the time needed for the lungs to fill or be emptied at a stable pressure. The expiratory time constant can indirectly represent lung heterogeneity during passive exhalation. It has been proposed that a shorter expiratory time constant can lead to VILI and a longer time constant can lead to hyperinflation and auto-PEEP.
The C20/C (Compliance 20/overall compliance) index measures the ratio of compliance of the last 20% of breath to the compliance of the entire breath. It is believed that C20/C > 1 indicates tidal recruitment and C20/C < 1 indicates overinflation.
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
- 19 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Patients with Acute respiratory failure needing mechanical ventilation
- •Diagnosis of Severe ARDS with severity: PF ratio < 150, with PEEP/CPAP > 5
排除标准
- •r2 < 0.95, monitored on the ventilator
- •Expiratory flow that is not first-order or non-exponential decay
- •Patients with Nor-epinephrine requirements > 0.1 mcg/kg/min within 2 hours of intubation
- •Patients requiring ECMO ( Extracorporeal membrane oxygenation)
- •Patients with COPD or pulmonary fibrosis with a premorbid FEV1 < 1.5 L
- •Severe atherosclerotic vascular disease
- •Patients with a chest tube, intra-abdominal hypertension or with its risk factors
- •Patients with structural heart disease including pulmonary hypertension (RVSP > 45) and heart failure
- •All comfort care orders in the ICU
- •Patients who underwent tracheostomy
结局指标
主要结局
Survival or mortality
时间窗: From the date of enrollment to 90 days from enrolment or date of death, whichever came first, assessed up to 90 days.
We will assess whether the patient would survive or not
次要结局
- MAKE ( Major adverse kidney events)(From the date of enrollment to 90 days from enrolment or date of death, whichever came first, assessed up to 90 days.)
- ICU and Hospital length of stay(From the date of enrollment to the number of days in ICU and in the hospital until discharge or date of death whichever came first, assessed up to 90 days)