Ratio of ''Central Venous-to-Arterial Co2 Gap'' to ''Arterial-to-Central Venous O2 Content Gap'' in Septic Shock

Role of "Central Venous-to-Arterial Carbon Dioxide" to "Arterial-to-Central Venous Oxygen Content" Ratio, as a Marker of Anaerobic Metabolism in Septic Shock

The high ratio of "central venous to arterial carbon dioxide" to "arterial to central venous oxygen content " is associated with elevated lactate in patients with septic shock.

So, the aim of the present study is to evaluate the ratio of "central venous-to-arterial CO2 tension or content" to "arterial-to-venous O2 content'' as an indicator of anaerobic metabolism in septic shock.

Study Overview

• Status: Active, not recruiting
• Conditions: Septic Shock
• Intervention / Treatment: Other: Fluid challenge (0.9 % NaCl)

Detailed Description

This is a prospective single center observational study that will be conducted in adult intensive care unit of Ain Shams University After being approved by local institutional ethic committee (Ain Shams University, Egypt). Informed consent was obtained from each participant's next of kin. The investigator will study mechanically ventilated participants. the attending physician's decision is to give IV fluids to participants due to the presence of at least one clinical sign of inadequate tissue perfusion due to septic shock : (a) systolic arterial pressure <90 mmHg, mean arterial pressure <65 mmHg, or the need for vasopressor infusion; (b) skin mottling; (c) lactate level >2 mmo/L; or (d) urinary output <0.5 mL/kg/h for ≥2 h. Jugular central venous and arterial catheters will be in place by the attending physician. Investigator will confirm the position of the tip of the central venous catheter in the superior vena cava or upper part of the right atrium on chest radiograph. Participants will be monitored by Flo Trac device as a part of routine management in local ICU.

A first set of measurements will be performed, including hemodynamic and tissue oxygenation variables (heart rate, mean arterial pressure, cardiac index (CI), oxygen delivery (DO2), oxygen consumption (VO2), Central venous oxygen saturation (ScvO2), arterial lactic acid level, central venous to arterial carbon dioxide tension difference (∆PCO2), central venous to arterial CO2 content difference (∆ContCO2), arterial-to-central venous oxygen content difference (∆ContO2), ∆ContCO2/∆ContO2 ratio and ∆PCO2/∆ContO2 ratio. 500 ml of isotonic saline 0.9% will be infused to the participants via a specific venous line over 15 minutes. Immediately after volume expansion, a second set of the previous measurements will be recorded. Ventilation parameters, Norepinephrine dose and sedation drugs will be kept constant during the fluid challenge.

After fluid challenge, Participants with an increase in cardiac index ≥15% will be defined as fluid responders. Fluid responders will be divided into 2 groups based on increase in oxygen consumption (VO2) ( < or ≥15%).

• Study Type: Observational
• Enrollment (Actual): 50

Contacts and Locations

Study Locations

• Egypt
  • Cairo, Egypt
    • AinShams

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 19 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Critically ill patients who will be admitted to intensive care units and eligible for the study.

Description

Inclusion Criteria:

1. Age >18 years.
2. Suspected infection focus
3. Mean blood pressure <65 mmHg, or required vasopressor infusion.
4. Lactic acid level >2 mmol/l.
5. Mechanically ventilated patients.

Exclusion Criteria:

1. Age equal or less than 18 years.
2. Pregnant women.
3. Liver cirrhosis Child-Pugh C.
4. Chronic obstructive pulmonary disease.
5. Previous episode of septic shock within the last 3 months.
6. Patients with a contraindication to volume expansion.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
VO2 ≥15 %; This group is classified based on increased oxygen consumption (VO2) ≥15 % by volume expansion in fluid responders	Other: Fluid challenge (0.9 % NaCl); 500 ml Fluid challenge of (0.9 % NaCl) will be given
VO2 <15 %; This group is classified based on increased oxygen consumption (VO2) < 15 % by volume expansion in fluid responders	Other: Fluid challenge (0.9 % NaCl); 500 ml Fluid challenge of (0.9 % NaCl) will be given

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluation of the change of the ratio of "central venous-to-arterial CO2 tension or content" to "arterial-to-central venous O2 content" as an effective marker to indicate anaerobic metabolism in septic shock.	To evaluate the change of the ratio of "central venous-to-arterial CO2 tension or content" to "arterial-to-central venous O2 content" between immediately before and Immedialey after volume expansion to indicate anaerobic metabolism in septic shock.	Measurements will be taken immediately before and immediately after volume expansion

Collaborators and Investigators

• Sponsor: Ain Shams University
• Investigators: Principal Investigator: Ahmed A Elsawy, Master, Ain shams university; Study Director: Ayman M Kamaly, Professor, Ain shams university

Study record dates

Study Major Dates

• Study Start (ACTUAL): July 20, 2020
• Primary Completion (ANTICIPATED): December 1, 2021
• Study Completion (ANTICIPATED): December 1, 2021

Study Registration Dates

• First Submitted: June 6, 2020
• First Submitted That Met QC Criteria: June 8, 2020
• First Posted (ACTUAL): June 11, 2020

Study Record Updates

• Last Update Posted (ACTUAL): August 23, 2021
• Last Update Submitted That Met QC Criteria: August 20, 2021
• Last Verified: August 1, 2021

More Information

Terms related to this study

• Keywords: sepsis; PCO2 gap; PCO2 gap/ O2 content gap
• Additional Relevant MeSH Terms: Pathologic Processes; Infections; Systemic Inflammatory Response Syndrome; Inflammation; Sepsis; Shock, Septic; Shock
• Other Study ID Numbers: FMASU MD 1322018

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No