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Recruiting NCT07653659

Hemodynamic Effects of Norepinephrine Reduction on Critical Closing Pressure in Distributive Shock

— Observational Distributive Shock Hemodynamic Assessment Critical Illness

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
The protocol lists: Not applicable- observational study.
Who it may be relevant to
Registry conditions: Distributive Shock, Hemodynamic Assessment, Critical Illness. Basic parameters: from 18 years · All.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
China
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

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Official title

Changes in Critical Closing Pressure and Derived Hemodynamic Parameters Following Norepinephrine Dose Reduction in Distributive Shock Patients: a Prospective Observational Study

Overview

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.

Detailed description

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.

Interventions

  • Other Not applicable- observational study
    Observation of hemodynamic parameters before and after clinically indicated norepinephrine dose reduction. No investigator-initiated intervention was performed.

Primary outcome measures

  • Change in critical closing pressure (Pcc, Unit: mmHg) before and after norepinephrine dose reduction [Time frame: Baseline and 30 minutes after norepinephrine dose reduction]
  • Change in tissue perfusion pressure (TPP, unit: mmHg) before and after norepinephrine dose reduction [Time frame: Baseline and 30 minutes after norepinephrine dose reduction]
Secondary outcome measures (3)
  • Change in mean systemic filling pressure analogue (Pmsf, unit: mmHg) before and after norepinephrine dose reduction [Time frame: Baseline and 30 minutes after norepinephrine dose reduction]
  • Change in Vascular waterfall (VW, unit: mmHg) before and after norepinephrine dose reduction [Time frame: Baseline and 30 minutes after norepinephrine dose reduction]
  • Change in capillary refill time (CRT, unit: seconds） [Time frame: Baseline and 30 minutes after norepinephrine dose reduction]

Eligibility criteria

Inclusion criteria

  • 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.

Exclusion criteria

  • 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.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model
Cohort

Study locations

China · 1 center
  • Peking Union Medical College Hospital — Beijing

Identifiers

NCT: NCT07653659 · pumch-micu202606

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗