Computerised transient hyperaemic response test--a method for the assessment of cerebral autoregulation

Area of Science:

• Neuroscience
• Medical Technology
• Critical Care Medicine

Background:

• Subarachnoid hemorrhage (SAH) poses significant risks to patients, with impaired cerebral autoregulation being a key concern.
• Accurate and timely assessment of cerebral autoregulation is crucial for managing SAH patients and predicting outcomes.
• Existing methods for assessing autoregulation can be complex or invasive, necessitating simpler bedside approaches.

Purpose of the Study:

• To develop and validate a simple bedside test for assessing cerebral autoregulation in subarachnoid hemorrhage patients.
• To implement a computerised program for the analysis of the transient hyperaemic response test (THRT) signals.
• To evaluate the correlation between the THRT results and the neurological state of SAH patients.

Main Methods:

• Utilized Transcranial Doppler (TCD) to measure middle cerebral artery blood flow velocity.
• Administered a brief common carotid compression to elicit a transient hyperaemic response.
• Developed a Windows-based program for automated signal analysis, detection of compression, and immediate result display/storage.

Main Results:

• The transient hyperaemic response test (THRT) successfully identified intact cerebral autoregulation based on post-compression flow velocity acceleration.
• The computerised analysis program was validated across 614 tests (552 off-line, 62 on-line).
• A significant correlation was observed between the computerised THRT results and the patients' neurological status.

Conclusions:

• The developed bedside THRT is a feasible and simple method for assessing cerebral autoregulation in SAH patients.
• Computerised analysis of TCD signals provides reliable and immediate results for clinical decision-making.
• This non-invasive test shows promise as a valuable tool for monitoring SAH patients and guiding therapeutic interventions.