NCT03816072

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

Simultaneous Quantification of Dynamic and Static Cerebral Autoregulation (CA) at Different Steady-state Mean Blood Pressures Under Anaesthesia.

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 66 (actual)
• Sponsor: Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA) · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

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

Interventions

Type	Name	Description
DRUG	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.
OTHER	Mechanical ventilation	Patientes are mechanically ventilated at 6 bpm to obtain low frequency blood pressure oscillations (\~0.1 Hz).
DRUG	Propofol	Propofol
DRUG	Sevoflurane	Sevoflurane

Timeline

• Start date: 2019-01-07
• Primary completion: 2019-09-23
• Completion: 2019-09-23
• First posted: 2019-01-25
• Last updated: 2021-05-27

Locations

1 site across 1 country: Netherlands