Vasopressor Use Improves Macrocirculation, But What Are Its Effects on Microcirculation?

N/ACompletedNCT07312071

Gaziosmanpasa Research and Education Hospital30 enrolled

Overview

To manage the treatment in the intensive care unit for patients with septic shock, central venous oxygen saturation (scvO2) is used as a macrocirculatory indicator, with a target value of 70% or higher being recommended. Tissue oxygenation (stO2) measurement can be implemented to assess the microcirculation in these patients, but a specific target value has not been established yet. The investigators believe that guiding the treatment of septic shock patients based on the measurement of microcirculation using stO2 and evaluating its correlation with scvO2 can reduce mortality. This study aims to investigate the independent impact of high-dose norepinephrine on microvascular reactivity assessed by NIRS-VOT in patients with septic shock, while also examining how these microcirculatory indices relate to the macrocirculatory marker ScvO₂.

Study Type

INTERVENTIONAL

Allocation

Purpose

DIAGNOSTIC

Masking

NONE

Enrollment

Conditions

Septic Shock Sepsis Tissue Ischemia Hemodynamic Instability

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Age 18 years or older * Diagnosis of septic shock * Receiving vasopressor and mechanical ventilation therapy * Presence of a central venous catheter that allows ScvO₂ sampling * Ability to obtain tissue oxygenation (stO₂) measurements using a NIRS probe placed on the thenar eminence * Written informed consent obtained from patient or legal representative Exclusion Criteria: * Local infection, wound, or skin lesion at the planned NIRS probe application site * Mean arterial pressure (MAP) \< 60 mmHg despite vasopressor therapy * Pregnancy * Inability to safely perform the vascular occlusion test (as judged by treating clinician) * Any condition preventing safe blood sampling or reliable stO₂ measurement

Outcomes

Primary Outcomes

Central Venous Oxygen Saturation (ScvO₂) Level

Central venous oxygen saturation will be measured from a central venous blood gas sample. The ScvO₂ value obtained at baseline will be recorded.

Time frame: Baseline (first 1 hour)

Norepinephrine Equivalent Vasopressor Dose

The vasopressor requirement will be expressed as the norepinephrine equivalent dose (NEq), calculated in µg/kg/min.

Time frame: Baseline (first 1 hour)

Baseline Tissue Oxygen Saturation (stO₂_baseline)

Tissue oxygen saturation will be measured non-invasively from the thenar eminence using Near-Infrared Spectroscopy (NIRS). The baseline stO₂ value will be recorded immediately before the vascular occlusion test.

Time frame: Within 1 hour of enrollment

Minimum Tissue Oxygen Saturation During Vascular Occlusion (stO₂_min)

During the vascular occlusion test (inflation of a cuff to stop arterial inflow), the lowest tissue oxygen saturation (stO₂\_min) recorded from the NIRS probe on the thenar eminence will be measured and recorded.

Time frame: Within 1 hour of enrollment

Maximum Tissue Oxygen Saturation After Reperfusion (stO₂_max)

After release of the vascular occlusion, the highest tissue oxygen saturation (stO₂\_max) value recorded during reactive hyperemia will be measured and recorded.

Time frame: Within 1 hour of enrollment

Recovery Time (From stO₂_min to stO₂_max)

Recovery time will be defined as the time interval between the minimum tissue oxygen saturation (stO₂\_min) during vascular occlusion and the maximum tissue oxygen saturation (stO₂\_max) after cuff release, as measured by NIRS on the thenar eminence.

Time frame: Within 1 hour of enrollment

Secondary Outcomes

28-Day All-Cause Mortality

Vital status (alive or deceased) will be assessed 28 days after enrollment to determine all-cause mortality.

Time frame: 28 days

Vasopressor Use Improves Macrocirculation, But What Are Its Effects on Microcirculation?

Overview

Conditions

Interventions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes