---
title: The Impact of Non-pulsatile Blood Flow on CO2-Reactivity
nct_id: NCT03732651
overall_status: COMPLETED
phase: NA
sponsor: Medical University of Vienna
study_type: INTERVENTIONAL
primary_condition: Cerebrovascular Circulation
countries: Austria
canonical_url: "https://parkinsonspathways.com/agent/trials/NCT03732651.md"
clinicaltrials_gov: "https://clinicaltrials.gov/study/NCT03732651"
ct_last_update_post_date: 2018-11-06
last_seen_at: "2026-05-12T06:24:02.785Z"
source: ClinicalTrials.gov (mirrored, no enrichment)
---
# The Impact of Non-pulsatile Blood Flow on CO2-Reactivity

**Official Title:** The Impact of Non-pulsatile Perfusion on Cerebral Blood Flow and Brain Oxygenation

**NCT ID:** [NCT03732651](https://clinicaltrials.gov/study/NCT03732651)

## Key Facts

- **Status:** COMPLETED
- **Phase:** NA
- **Study Type:** INTERVENTIONAL
- **Target Enrollment:** 32
- **Lead Sponsor:** Medical University of Vienna
- **Conditions:** Cerebrovascular Circulation
- **Start Date:** 2008-06-11
- **Completion Date:** 2013-12-02
- **CT.gov Last Update:** 2018-11-06

## 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.

## Eligibility

- **Minimum age:** 15 Years
- **Maximum age:** 75 Years
- **Sex:** ALL
- **Healthy Volunteers:** No

```
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
```

## Arms

- **non-pulsatile blood flow** (EXPERIMENTAL)
- **pulsatile blood flow** (EXPERIMENTAL)

## Interventions

- **alteration of PaCO2 level** (PROCEDURE) — step changes between 30, 40 and 50 mmHg

## Primary Outcomes

- **CO2- Reactivity of cerebral vessels during cardiopulmonary bypass using nonpulsatile blood flow and postoperative on ICU under physiological pulsatile blood flow** _(time frame: 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.

## Locations (1)

- medical University of Vienna, Vienna, Austria

## Recent Field Changes (last 30 days)

- `status.overallStatus` — added _(2026-05-12)_
- `status.primaryCompletionDate` — added _(2026-05-12)_
- `status.completionDate` — added _(2026-05-12)_
- `status.lastUpdatePostDate` — added _(2026-05-12)_
- `design.phases` — added _(2026-05-12)_
- `design.enrollmentCount` — added _(2026-05-12)_
- `eligibility.criteria` — added _(2026-05-12)_
- `eligibility.minAge` — added _(2026-05-12)_
- `eligibility.maxAge` — added _(2026-05-12)_
- `eligibility.sex` — added _(2026-05-12)_
- `outcomes.primary` — added _(2026-05-12)_
- `armsInterventions.arms` — added _(2026-05-12)_
- `armsInterventions.interventions` — added _(2026-05-12)_
- `sponsor.lead` — added _(2026-05-12)_
- `results.hasResults` — added _(2026-05-12)_
- `locations.medical university of vienna|vienna||austria` — added _(2026-05-12)_

---

*Canonical: https://parkinsonspathways.com/agent/trials/NCT03732651.md*  
*Source data (authoritative): https://clinicaltrials.gov/study/NCT03732651*  
*This page is a raw mirror with no AI summary, no editorial enrichment, and no Parkinson's-specific filtering.*