Discordance Between Capillary Refill Time and Oxygen Extraction Ratio in Septic Shock

Sponsor
Istanbul University - Cerrahpasa
Study ID
NCT07774962
Status
Recruiting
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Conditions

  • Sepsis
  • Septic Shock

Eligibility Criteria

Sex
ALL
Age
18 Years - N/A
Healthy Volunteers
Not accepted

Interventions

  • Capillary refill time (CRT) — DIAGNOSTIC_TEST
    Non-invasive, standardized bedside measurement of capillary refill time on the right index finger.
  • Oxygen extraction ratio (O₂ER) assessment — DIAGNOSTIC_TEST
    Oxygen extraction ratio calculated as (SaO₂ - ScvO₂)/SaO₂ from routinely obtained arterial and central venous blood gases.

Study Details

In septic shock, restoring large-vessel (macrocirculatory) perfusion-reflected by a normal capillary refill time (CRT)-does not always mean that oxygen use at the tissue level has recovered. This mismatch, sometimes called loss of hemodynamic coherence, may be detectable by comparing CRT with the oxygen extraction ratio (O₂ER), a marker of how much oxygen the tissues are extracting from the blood. Patients whose CRT has normalized but whose O₂ER remains abnormal-either too high (suggesting oxygen delivery that is insufficient for demand) or too low (suggesting microcirculatory shunting)-are considered to have a "discordant" perfusion phenotype. This prospective, single-center, observational cohort study aims to determine how often this CRT-O₂ER discordance occurs at the 6th hour of resuscitation in adult patients with septic shock, and whether it is associated with 28-day mortality. Approximately 100 consecutive adult patients diagnosed with septic shock (with pre-existing central venous and arterial catheters) will be followed. Clinical and laboratory measurements-including CRT, O₂ER, lactate, mottling score, and organ dysfunction scores-will be recorded at hours 0, 6, 12, and 24, with the main phenotype grouping performed at hour 6. The study is purely observational: CRT is a painless, non-invasive bedside measurement, and O₂ER is calculated from blood gas samples already drawn as part of routine care, so no additional interventions or blood draws are performed for research purposes.

Key Dates

First listed
Aug 19, 2026
Start date
Aug 17, 2026
Status verified
Aug 2026
Primary completion
Jun 17, 2027
Completion
Jul 17, 2027

Study Design

Enrollment
100 participants (estimated)

Arms

  • Arm: septic schoc cohort
    Consecutive adult patients (≥18 years) admitted to the intensive care unit and diagnosed with septic shock according to the Surviving Sepsis Campaign (SSC) 2026 guideline, who have pre-existing central venous and arterial catheters. Patients are prospectively followed while receiving standard care, with serial measurements at hours 0, 6, 12, and 24 (time zero = vasopressor initiation). At hour 6, patients are classified into perfusion phenotypes based on capillary refill time (CRT) and oxygen extraction ratio (O₂ER): concordant normal, discordant with high O₂ER, discordant with low O₂ER, and concordant abnormal. The primary group of interest is the combined discordant phenotype (normalized CRT with abnormal O₂ER).

Primary Outcome Measure

Prevalence of the discordant CRT-O₂ER phenotype [ Time Frame: At hour 6 of resuscitation (6 hours after vasopressor initiation) ]

Central Contacts

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