Cerebrovascular Effects of the Use of Alpha-stat or pH-stat Management of Cardiopulmonary Bypass
1 other identifier
observational
200
1 country
1
Brief Summary
Type 2 diabetes mellitus (T2DM) poses a significant burden on the patients and the health care system. The increasing number of surgery performed in elderly population results in an increased number of perioperative T2DM-related adverse effects. T2DM has a prevalence of 30-40% in a population undergoing cardiovascular surgery. Cardiac surgery, especially cardiopulmonary bypass (CPB) is also known to deteriorate cerebral oxygenation. Furthermore, acid-base balance of patients undergoing CPB can be managed using two main regimes: alpha-stat and pH-stat. The use of pH-stat acid-base management involves maintaining the patient's temperature-corrected pH at a constant level (7.40) and maintaining normocapnia (pCO2 of 40 mmHg). Alpha-stat acid-base management on the other hand is performed by maintaining the ionization state of histidine by keeping the pH stable when a standardized temperature of 37C is used. Therefore, while a constant pH (7.40) and normocapnia (pCO2 of 40 mmHg) are targeted when measured at 37C, the hypothermia applied during CPB will result in a lower pCO2 and in a relative respiratory alkalosis. Previous studies investigating alpha-stat and pH-stat managements demonstrated increased jugular venous oxygen concentrations when pH-stat management was applied. Therefore, our study is aimed at characterizing the effects of an alpha-stat or pH-stat acid-base management regime on the cerebral oxygenation, parameters of regional cerebral oxygen supply and demand during and following CPB in diabetic patients. These parameters include regional cerebral tissue oxygen saturation (rSO2), central venous oxygen saturation ScvO2) and the physiological saturation gap between ScvO2 and rSO2 (gSO2).
Trial Health
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participants targeted
Target at P75+ for all trials
Started Feb 2019
1 active site
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
January 22, 2019
CompletedFirst Posted
Study publicly available on registry
January 25, 2019
CompletedStudy Start
First participant enrolled
February 1, 2019
CompletedPrimary Completion
Last participant's last visit for primary outcome
July 1, 2020
CompletedStudy Completion
Last participant's last visit for all outcomes
July 1, 2020
CompletedMay 16, 2019
May 1, 2019
1.4 years
January 22, 2019
May 14, 2019
Conditions
Keywords
Outcome Measures
Primary Outcomes (2)
Cerebral tissue oxygen saturation
The spatially resolved continuous-wave NIRS technique is applied to estimate cerebral tissue oxygen saturation. This monitor uses two different wavelengths (730 and 810 nm) and has two detectors positioned 3 and 4 cm from the light source. Computing the differences between the intensity of the emitted and the reflected light with two receivers allows the measurement of the oxygen saturation of the cerebral cortex. In this study, two adult sensors are applied on the left and right sides of the patient's forehead symmetrically, and the cerebral-tissue oxygen saturation is monitored continuously during the surgical procedures and the data are registered in each protocol stage. The mean value of the rSO2 measured by the sensors is calculated for each protocol stage and used for further analyses.
Intraoperative interval during cardiac surgery starting from anaesthesia induction until end of the surgery. (approx. 180 minutes, measurements at ~0-40-140-160 minutes).
Central venous oxygen saturation
The central venous oxygen saturation is measured from central venous blood samples (Radiometer ABL 505, Copenhagen, Denmark). The proper positioning of the central venous catheter is verified by the surgeon via manually palpating the catheter tip.
Intraoperative interval during cardiac surgery starting from anaesthesia induction until end of the surgery. (approx. 180 minutes, measurements at ~0-40-140-160 minutes).
Study Arms (4)
Group T2DM-alpha
Patients with diabetes mellitus undergoing CPB with alpha-stat acid-base management
Group T2DM-pH
Patients with diabetes mellitus undergoing CPB with pH-stat acid-base management
Group Ctrl-alpha
Control patients undergoing CPB with alpha-stat acid-base management
Group Ctrl-pH
Control patients undergoing CPB with pH-stat acid-base management
Interventions
All groups undergo elective cardiopulmonary bypass (CPB)
Acid-base status during CPB will be maintained using the alpha-stat regime
Acid-base status during CPB will be maintained using the pH-stat regime
Eligibility Criteria
The patients enrolled at the Second Department of Internal Medicine and Cardiology Centre Cardiac Surgical Unit, University of Szeged
You may qualify if:
- Patients undergoing cardiac surgery with or without diabetes mellitus
- age between 18-80 years
You may not qualify if:
- patients older than 80 years of age
- poor ejection fraction (\<40%)
- unilateral internal carotid stenosis (\>75%)
- medical history of smoking
- medical history of chronic obstructive pulmonary disease
- medical history of stroke
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Szeged Universitylead
- GINOPcollaborator
- Hungarian Basic Research Councilcollaborator
Study Sites (1)
Cardiology Centre Cardiac Surgical Unit and Second Department of Internal Medicine, University of Szeged
Szeged, Csongrád megye, 6725, Hungary
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Central Study Contacts
Study Design
- Study Type
- observational
- Observational Model
- CASE CONTROL
- Time Perspective
- PROSPECTIVE
- Sponsor Type
- OTHER
- Responsible Party
- PRINCIPAL INVESTIGATOR
- PI Title
- Professor
Study Record Dates
First Submitted
January 22, 2019
First Posted
January 25, 2019
Study Start
February 1, 2019
Primary Completion
July 1, 2020
Study Completion
July 1, 2020
Last Updated
May 16, 2019
Record last verified: 2019-05