The Impact of Non-pulsatile Blood Flow on CO2-Reactivity

The Impact of Non-pulsatile Perfusion on Cerebral Blood Flow and Brain Oxygenation

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT03732651

Enrollment

Registered

2018-11-06

Start date

2008-06-11

Completion date

2013-12-02

Last updated

2018-11-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cerebrovascular Circulation

Brief summary

The investigators hypothezised that CO2-reactivity of cerebral vessels is affected by systemic non-pulsatile blood flow. Patients undergoing elective cardiac surgery with CPB were enrolled in this prospective case control study. Blood flow velocity in the middle cerebral artery as well as regional cerebral oxygenation was determined during step changes of PaCO2 between 30, 40, and 50 mmHg. Measurements were conducted intraoperatively during non-pulsatile as well as postoperatively after admission to the ICU under pulsatile blood flow.

Interventions

PROCEDUREalteration of PaCO2 level

step changes between 30, 40 and 50 mmHg

Study design

Allocation

NON_RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

BASIC_SCIENCE

Masking

SINGLE (Outcomes Assessor)

Intervention model description

Each patient served as his own control.

Eligibility

Sex/Gender

ALL

Age

15 Years to 75 Years

Healthy volunteers

Inclusion criteria

* undergoing elective cardiac surgery with cardiopulmonary bypass

Exclusion criteria

* Carotid artery stenosis (\> 50%) * Neurological pathologies * COPD with CO2 retention * Women of childbearing age

Design outcomes

Primary

Measure	Time frame	Description
CO2- Reactivity of cerebral vessels during cardiopulmonary bypass using nonpulsatile blood flow and postoperative on ICU under physiological pulsatile blood flow	first time-point: intraoperative, during cardiopulmonary bypass, duration up to 300minutes. Second time-point: on ICU, postoperatively under pulsatile blood flow, duration of measurement up to 100minutes for each patient	Relation between PaCO2 level and cerebral blood flow velocity will be assessed during non-pulsatile and pulsatile blood flow. Measurements will be performed using trancranial doppler to measure flow velocity of the middle cerebral artery. Further, NIRS will be used to measure oxygen saturation of the brain. Measurements will be performed during step changes of PaCO2 (at 30mmHg, 40mmHg and 50mmHg.

Countries

Austria

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 20, 2026