Observing Blood Flow Changes After Norepinephrine Dose Reduction in Adults with Distributive Shock Using PiCCO Monitoring

What this Trial Is About

This research aims to observe changes in critical closing pressure Pcc and related blood flow measures in adult patients with distributive shock who are mechanically ventilated and receiving norepinephrine. The study focuses on patients where doctors decide to reduce norepinephrine dose based on clinical judgment, with mean arterial pressure MAP maintained between 75 and 85 mmHg prior to reduction. The goal is to understand how hemodynamic parameters adjust after decreasing norepinephrine, providing insight into vascular function during shock treatment. Participants have monitoring devices called PiCCO catheters in place to measure blood flow and pressure. Researchers measure Pcc and other parameters like tissue perfusion pressure, mean systemic filling pressure analogue, and vascular waterfall before and 30 minutes after norepinephrine dose reduction. The norepinephrine dose reduction is made by the attending physician without influence from investigators. Measurements use a stepwise inspiratory hold maneuver during mechanical ventilation, capturing cardiac output and arterial pressure at specified pressures. During the study, participants are observed without altering their treatment except for the clinically indicated norepinephrine dose change. Evaluations include recording hemodynamic values at baseline and 30 minutes post-dose reduction, ensuring stable MAP variation. The main outcomes measured are changes in Pcc and tissue perfusion pressure, with additional monitoring of mean systemic filling pressure, vascular waterfall, and capillary refill time. The study spans from initial observation through the post-reduction period, with no experimental intervention other than data collection.

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