Parameters of Cerebral Perfusion

Cardiopulmonary Bypass Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02806492
• Other study ID #: NL48417.041.14
• Status: Completed
• Phase: N/A
• First received: June 15, 2016
• Last updated: June 7, 2017
• Start date: January 2016
• Est. completion date: March 17, 2017

Study information

• Verified date: June 2017
• Source: UMC Utrecht
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 15
• Est. completion date: March 17, 2017
• Est. primary completion date: March 17, 2017
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

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.

Related Conditions & MeSH terms

• Cardiopulmonary Bypass
• Cerebral Oxygenation
• Cerebral Perfusion

Intervention

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.
• 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.
• 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.
• 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.
• 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 a1-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.

Locations

Country	Name	City	State
Netherlands	UMC Utrecht	Utrecht

Sponsors (1)

Lead Sponsor	Collaborator
UMC Utrecht

Country where clinical trial is conducted

Netherlands, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	regional cerebral oxygen saturation		During surgery
Primary	mean velocity of blood flow of the middle cerebral artery		During surgery