Parameters of Cerebral Perfusion

June 7, 2017 updated by: Dr. B. van Zaane, UMC Utrecht

Blood Pressure or Cardiac Output - the Influence on Cerebral Perfusion During Cardiopulmonary Bypass

The purpose of this study is to determine whether cerebral blood flow and cerebral tissue oxygenation is most dependent on cardiac output or on mean arterial pressure in patients undergoing cardiac surgery with the use of cardiopulmonary bypass.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

15

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Undergoing cardiopulmonary bypass for CABG a
  • having an appropriate temporal bone window for reliable TCD monitoring
  • needing pharmacological intervention because of hypotension before going on CPB.

Exclusion Criteria:

  • requiring hypothermia during surgery
  • requiring emergency surgery
  • contraindication for phenylephrine,
  • having known brain pathology (e.g. Cerebral Vascular Accident (CVA) or increased intracranial pressure
  • having a history of severe carotid artery stenosis.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Patient for cardiac surgery
All patient undergo the 5 different intervention in a randomised matter.
Other: 50-100ug phenylephrine before CPB
In this intervention we will administer 50-100 μg phenylephrine to the patient before CPB is started. This intervention will take place when the patient shows hypotension (MAP <60mmHg, according to protocol22). Because of the increase in PVR there will be a baroreceptor-reflex-mediated decrease in CO. On-line, we will quantify the percentage decrease in systemic blood flow (i.e. CO) by using the Modelflow algoritm incorporated in a non-invasive beat-to-beat finger blood pressure monitor. This will allow us to obtain a reference for the decrease in CO to use in the next interventions. Our hypothesis is that CO will decrease because of the baroreceptor-reflex. During this intervention NIRS and TCD MCA will be recorded.
Other: 50-100ug phenylephrine during CPB
In this intervention we will induce only 1 component of the changes at intervention (1), being the increase in MAP of approximately 20 mmHg by administrating 50-100 μg phenylephrine. The CPB enables us to maintain a constant CO and thus eliminating the baroreceptor-reflex. During this intervention NIRS and TCD MCA will be recorded.
Other: decreasing CPB flow
With this intervention we will only create a change in CO, which enables us to eliminate the effect of blood pressure. We will modify CPB flow to achieve the CO decrease (in %) measured at intervention (1) meaning: pre-CPB after the bolus of 50-100 μg phenylephrine. In the case of unexpected increase (in %) of CO measured at intervention (1), we will still decrease CPB flow so we will be able to analyse decrease as well as increase in CPB flow. During this intervention NIRS and TCD MCA will be recorded.
Other: Decreasing CPB flow AND 50-100ug phenylephrine
In this intervention we will simulate the 'normal' physiological state when administering phenylephrine. We will modify CPB flow to achieve the percentage change CO as observed during intervention (1) as well as administrate 50-100 μg phenylephrine. We expect to see similar outcomes as in intervention (1). During this intervention NIRS and TCD MCA will be recorded.
Other: Increasing CPB flow
In this last intervention we will create an increase in MAP without using phenylephrine but only by increasing CO. This enables us to eliminate a possible direct α1-adrenergic effect on the cerebral vasculature. MAP will be raised approximately 20 mmHg by increasing CPB flow 20%. During this intervention NIRS and TCD MCA will be recorded.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
regional cerebral oxygen saturation
Time Frame: During surgery
During surgery
mean velocity of blood flow of the middle cerebral artery
Time Frame: During surgery
During surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

UMC Utrecht

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 1, 2016

Primary Completion (Actual)

March 17, 2017

Study Completion (Actual)

March 17, 2017

Study Registration Dates

First Submitted

June 15, 2016

First Submitted That Met QC Criteria

June 15, 2016

First Posted (Estimate)

June 20, 2016

Study Record Updates

Last Update Posted (Actual)

June 8, 2017

Last Update Submitted That Met QC Criteria

June 7, 2017

Last Verified

June 1, 2017

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • NL48417.041.14

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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