Hemodynamic Instability, Sepsis, Septic Shock, Tissue Ischemia
Conditions
Keywords
Tissue oxygenation, Vazopressor, Septic Shock, Sepsis, microcirculation
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.
Interventions
DIAGNOSTIC_TESTVascular Occlusion 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.
Sponsors
Gaziosmanpasa Research and Education Hospital
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Baseline Tissue Oxygen Saturation (stO₂_baseline) | Within 1 hour of enrollment | 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. |
| Central Venous Oxygen Saturation (ScvO₂) Level | Baseline (first 1 hour) | Central venous oxygen saturation will be measured from a central venous blood gas sample. The ScvO₂ value obtained at baseline will be recorded. |
| Norepinephrine Equivalent Vasopressor Dose | Baseline (first 1 hour) | The vasopressor requirement will be expressed as the norepinephrine equivalent dose (NEq), calculated in µg/kg/min. |
| Recovery Time (From stO₂_min to stO₂_max) | Within 1 hour of enrollment | 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. |
| Minimum Tissue Oxygen Saturation During Vascular Occlusion (stO₂_min) | Within 1 hour of enrollment | 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. |
| Maximum Tissue Oxygen Saturation After Reperfusion (stO₂_max) | Within 1 hour of enrollment | After release of the vascular occlusion, the highest tissue oxygen saturation (stO₂\_max) value recorded during reactive hyperemia will be measured and recorded. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 28-Day All-Cause Mortality | 28 days | Vital status (alive or deceased) will be assessed 28 days after enrollment to determine all-cause mortality. |
Countries
Turkey (Türkiye)
Outcome results
None listed