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

NCT07312071 | Completed

• 1 other identifier: 1234
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Tissue Ischemia; Hemodynamic Instability; Septic Shock; Sepsis

Keywords

Tissue oxygenation; Vazopressor; Septic Shock; Sepsis; microcirculation

Outcome Measures

Primary Outcomes (6)

• 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.

  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.

  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.

  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.

  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.

  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.

  Within 1 hour of enrollment

Secondary Outcomes (1)

• 28-Day All-Cause Mortality

  28 days

Study Arms (1)

Study group

OTHER

The study will include adult patients aged 18 and above who are receiving vasopressor therapy due to septic shock in the intensive care unit.

Diagnostic Test: Vascular Occlusion Test

Interventions

Vascular Occlusion Test DIAGNOSTIC_TEST

The vascular occlusion test is a procedure performed to assess the vascular status and perfusion of a limb. It involves temporarily stopping blood flow to the limb by applying a blood pressure cuff.

Study group

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Gaziosmanpasa Research and Education Hospital: lead

Study Sites (1)

Gaziosmanpasa Training Research Hospital

Istanbul, 34255, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Shock, Septic; Sepsis

Condition Hierarchy (Ancestors)

Infections; Systemic Inflammatory Response Syndrome; Inflammation; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Shock

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Anesthesiology and Reanimation Specialist

Study Record Dates

• First Submitted: July 7, 2023
• First Posted: December 31, 2025
• Study Start: April 1, 2023
• Primary Completion: August 31, 2023
• Study Completion: September 30, 2023
• Last Updated: December 31, 2025

Record last verified: 2025-12

Locations

TU (1)