Changes in Critical Closing Pressure and Derived Hemodynamic Parameters Following Norepinephrine Dose Reduction in Distributive Shock Patients: a Prospective Observational Study
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 30
- 试验地点
- 1
研究概览
简要总结
This study prospectively observes changes in critical closing pressure (Pcc) and derived hemodynamic parameters in mechanically ventilated distributive shock patients when clinically indicated norepinephrine dose reduction is performed by the attending physician. Pcc is measured before and 30 minutes after dose reduction using a stepwise inspiratory hold maneuver via PiCCO monitoring.
详细描述
In distributive shock patients receiving norepinephrine with MAP maintained in the 75-85 mmHg range, attending physicians may reduce norepinephrine dose based on clinical judgment. This study observes hemodynamic changes associated with such reductions without any investigator-initiated intervention. Critical closing pressure (Pcc) and derived parameters including tissue perfusion pressure (TPP), mean systemic filling pressure analogue (Pmsf), and vascular waterfall (VW) are measured at baseline and 30 minutes after dose reduction, provided MAP variability is less than 5 mmHg. Pcc is derived from linear regression of simultaneously measured cardiac output (CO) and mean arterial pressure (MAP) during stepwise inspiratory hold maneuvers. Steady-state CO and MAP values are recorded during the final 3 seconds of 12-second inspiratory holds at plateau pressures of 5, 15, 25, and 35 cmH2O. The x-intercept of the CO-MAP regression line is taken as Pcc.
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
- •Adult distributive shock patients aged ≥18 years;
- •Receiving norepinephrine infusion with MAP in the 75-85 mmHg range;
- •PiCCO catheter in situ;
- •Under mechanical ventilation;
- •Clinically indicated norepinephrine dose reduction per attending physician judgment.
排除标准
- •Significant cardiac arrhythmia affecting CO measurement reliability;
- •Contraindication to airway plateau pressure maneuver;
- •Active titration of other vasoactive agents within 30 minutes prior to measurement;
- •Hemodynamic instability making it impossible to reduce norepinephrine dose.
研究者
Bin Du
Professor
Peking Union Medical College Hospital