Parameters of Cerebral Perfusion

Sponsor

UMC Utrecht (Other)

Overall Status

Completed

CT.gov ID

NCT02806492

Collaborator

(none)

Enrollment

Location

Arm

14.5

Actual Duration (Months)

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

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.

Condition or Disease	Intervention/Treatment	Phase
Cerebral Perfusion Cerebral Oxygenation Cardiopulmonary Bypass	Other: 50-100ug phenylephrine before CPB Other: 50-100ug phenylephrine during CPB Other: decreasing CPB flow Other: Decreasing CPB flow AND 50-100ug phenylephrine Other: Increasing CPB flow	N/A

Study Design

Study Type:

Interventional

Actual Enrollment :

15 participants

Allocation:

N/A

Intervention Model:

Single Group Assignment

Masking:

None (Open Label)

Primary Purpose:

Basic Science

Official Title:

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

Actual Study Start Date :

Jan 1, 2016

Actual Primary Completion Date :

Mar 17, 2017

Actual Study Completion Date :

Mar 17, 2017

Arms and Interventions

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.

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.

Outcome Measures

Primary Outcome Measures

regional cerebral oxygen saturation [During surgery]
mean velocity of blood flow of the middle cerebral artery [During surgery]

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

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.

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	UMC Utrecht	Utrecht		Netherlands	3584CX

Sponsors and Collaborators

UMC Utrecht

Investigators

None specified.

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

Responsible Party:

Dr. B. van Zaane, MD PhD, UMC Utrecht

ClinicalTrials.gov Identifier:

NCT02806492

Other Study ID Numbers:

NL48417.041.14

First Posted:

Jun 20, 2016

Last Update Posted:

Jun 8, 2017

Last Verified:

Jun 1, 2017

Additional relevant MeSH terms:

Phenylephrine

Oxymetazoline

Study Results

No Results Posted as of Jun 8, 2017