Quantification of Dynamic and Static Cerebral Autoregulation (CA) Under Anaesthesia

NCT ID: NCT03816072

Last Updated: 2021-05-27

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 66 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2019-01-07
• Study Completion Date: 2019-09-23

Brief Summary

Cerebral autoregulation (CA) is the mechanism by which the brain vasculature maintains constancy of cerebral blood flow (CBF). Reliable direct measurements of CBF at different blood pressure levels are difficult because they are invasive and time-consuming. This type of measurement to quantify CA is generally referred to as static cerebral autoregulation (sCA). Alternatively, it is possible to measure CA indirectly from blood pressure oscillations. Dynamic cerebral autoregulation (dCA) measures how quickly the cerebral vessels react to a change in blood pressure to normalize CBF. Since the introduction of transcranial Doppler ultrasound (TCD), it has become possible to estimate CBF velocity relatively easy, which in turn correlates well with CBF changes. This method is widely used to quantify dCA. However, it is not clear how sCA correlates with dCA over a range of physiologic mean blood pressure (MBP). It is important to compare different methods of assessing CA, because impaired CA may result in increased risk of perioperative complications such as stroke. In this study, the investigators were interested in establishing the relationship between sCA and dCA during surgery under general anesthesia. The investigators aim to compare these methods during propofol and sevoflurane anesthesia.

Conditions

Cerebrovascular Circulation

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Propofol

ASA-I/II patients undergoing elective, non-cardiothoracic surgery with intravenous anaesthesia (propofol).

Group Type: ACTIVE_COMPARATOR

Phenylephrine infusion

Intervention Type: DRUG

Correction of anesthesia induced hypotension with phenylephrine to obtain sCA and dCA measurements at 60, 70, 80, 90 and 100 mmHg mean blood pressure. This is achieved by stepwise increases in phenylephrine infusion dose.

Mechanical ventilation

Intervention Type: OTHER

Patientes are mechanically ventilated at 6 bpm to obtain low frequency blood pressure oscillations (\~0.1 Hz).

Propofol

Intervention Type: DRUG

Propofol

Sevoflurane

ASA-I/II patients undergoing elective, non-cardiothoracic surgery with inhalational anaesthesia (sevoflurane).

Group Type: ACTIVE_COMPARATOR

Phenylephrine infusion

Intervention Type: DRUG

Correction of anesthesia induced hypotension with phenylephrine to obtain sCA and dCA measurements at 60, 70, 80, 90 and 100 mmHg mean blood pressure. This is achieved by stepwise increases in phenylephrine infusion dose.

Mechanical ventilation

Intervention Type: OTHER

Patientes are mechanically ventilated at 6 bpm to obtain low frequency blood pressure oscillations (\~0.1 Hz).

Sevoflurane

Intervention Type: DRUG

Sevoflurane

Interventions

Phenylephrine infusion

Correction of anesthesia induced hypotension with phenylephrine to obtain sCA and dCA measurements at 60, 70, 80, 90 and 100 mmHg mean blood pressure. This is achieved by stepwise increases in phenylephrine infusion dose.

Intervention Type: DRUG

Mechanical ventilation

Patientes are mechanically ventilated at 6 bpm to obtain low frequency blood pressure oscillations (\~0.1 Hz).

Intervention Type: OTHER

Propofol

Propofol

Intervention Type: DRUG

Sevoflurane

Sevoflurane

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• ASA-I or ASA-II, willing and able to give written informed consent, scheduled for elective, non-cardiothoracic surgery under general anaesthesia and age 18 years and above.

Exclusion Criteria

• Patient related

• Unable/ unwilling to participate
• ASA-III or higher
• Age < 18 years
• History of: uncontrolled hypertension, diabetes, Parkinson's disease, uncontrolled cardiac arrhythmia, Pure autonomic failure (formerly called idiopathic orthostatic hypotension), Multiple system atrophy with autonomic failure (formerly called Shy-Drager syndrome), Addison's disease and hypopituitarism, pheochromocytoma, peripheral autonomic neuropathy (e.g., amyloid neuropathy, idiopathic autonomic neuropathy), known cardiomyopathy, extreme left ventricle hypertrophy or ejection fraction < 30%, proven or suspected allergy for any of the medication used during induction of anaesthesia, malignant hyperthermia.
• Unability to record transcranial Doppler ultrasound due to anatomical variance (~5% of population)
• Contra-indications for intravenous or inhalational anaesthesia.
• Contra-indications for phenylephrine: severe hypertension, peripheral vascular illness, severe hyperthyroidism
• Simultaneous use of MAO-inhibitors, dopaminergic or vasoconstrictor ergot alkaloids (bromocriptine, cabergoline, pergolide, ergotamine, methylergometrine, methysergide), linezolid, tricyclic antidepressants, serotonin-norepinephrine reuptake inhibitors, digoxin, quinidine, oxytocin.
• Surgery related

• Day case surgery
• Laparoscopy with CO2 insufflation
• Extreme positioning during surgery (head-down/up tilt, lateral decubitus position, prone)
• Surgery < 60 minutes.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)

OTHER

Sponsor Role: lead

Responsible Party

Niek Sperna Weiland

MD

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Jeroen Hermanides, Dr.

Role: PRINCIPAL_INVESTIGATOR

Amsterdam UMC, location AMC

Locations

Amsterdam UMC, location AMC

Amsterdam, North Holland, Netherlands

Countries

Netherlands

References

van den Dool REC, Sperna Weiland NH, Schenk J, Kho E, Veelo DP, van der Ster BJP, Immink RV. Dynamic cerebral autoregulation during step-wise increases in blood pressure during anaesthesia: A nonrandomised interventional trial. Eur J Anaesthesiol. 2023 Jun 1;40(6):407-417. doi: 10.1097/EJA.0000000000001798. Epub 2023 Feb 6.

Reference Type: DERIVED

PMID: 36655712 (View on PubMed)

Other Identifiers

METC 2018_230

Identifier Type: -

Identifier Source: org_study_id