NIRS vs TCD for Cerebrovascular Autoregulation During Non-cardiac Surgery

Completed

• Conditions: Cerebrovascular Circulation

• Registration Number: NCT04978558
• Lead Sponsor: Universitätsklinikum Hamburg-Eppendorf

Brief Summary

Postoperative neurocognitive disorders (NCD) are of high priority in perioperative management. The risk of suffering from NCD after surgery may be increased due to perioperative impairment of cerebrovascular autoregulation and thereby inadequate cerebral perfusion. Cerebrovascular autoregulation refers to the ability of cerebral arterioles to ensure constant cerebral blood flow independently of fluctuations in systemic blood pressure.

Cerebrovascular autoregulation can be measured based on mean arterial pressure (MAP) and a surrogate for cerebral blood flow using the correlation method. Until today, measurement of cerebral blood flow velocity assessed with transcranial Doppler sonography (TCD) is most commonly used as a non-invasive surrogate for cerebral blood flow. Alternatively, cerebral oxygenation measured with near-infrared spectroscopy (NIRS) can be used as another surrogate.

The study includes three substudies:

1. To compare NIRS and TCD for the assessment of perioperative cerebrovascular autoregulation in patients undergoing major non-cardiac surgery with an increased risk of bleeding.

2. To compare MAP for optimal cerebrovascular autoregulation before induction of general anesthesia with MAP for optimal cerebrovascular autoregulation during or after general anesthesia.

3. To analyze the association between the time-weighted average MAP below the MAP for optimal cerebrovascular autoregulation and postoperative NCD.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2021-07-18
• Study First Submitted QC: 2021-07-18
• Study First Posted: 2021-07-27
• Study Start: 2021-08-09
• Primary Completion: 2023-09-29
• Study Completion: 2024-09-19
• Status Verified: 2025-09
• Last Update Submitted: 2025-09-28
• Last Update Posted: 2025-10-02

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 509

Inclusion Criteria

• Age ≥ 18 years
• Elective surgery with a minimum duration of 120 minutes
• General anesthesia
• expected blood loss > 500 ml

Exclusion Criteria

• Temporal bone window failure (substudy 1)
• Cerebrovascular disease
• Cardiac surgery
• Neurosurgery

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Equivalence of NIRS-based and TCD-based intraoperative measurement of cerebrovascular autoregulation	up to 4 hours during surgery	calculation of cerebral autoregulation indices based on near-infrared spectroscopy and transcranial Doppler sonography
optimal MAP during NIRS-based measurement of cerebrovascular autoregulation	up to 2 hours after surgery	MAP at lowest cerebral autoregulation index COx
delirium and postoperative NCD after surgery (composite)	days 1 to 4 after surgery (delirium), day 7 after surgery or at day of discharge from hospital (NCD)	screening for postoperative delirium; neuropsychological testing for the assessment of cognitive function

Secondary Outcome Measures

Name	Time	Method
optimal MAP during TCD-based measurement of cerebrovascular autoregulation	up to 4 hours during surgery	MAP at lowest cerebral autoregulation index (Mx)
postoperative delirium between day 1 and 4 after surgery	days 1 to 4 after surgery	screening for postoperative delirium
delayed neurocognitive recovery at day 7 after surgery or before hospital discharge	day 7 after surgery or at day of discharge from hospital	neuropsychological assessment
length of hospital stay	date of discharge from hospital (up to 30 days)	duration of hospital stay (in days) between surgery and discharge
length of ICU stay	date of discharge from ICU (up to 30 days)	duration of intensive care unit stay (in days) between surgery and discharge
mortality at 3 months after surgery	3 months after surgery	survival status three months after surgery

Trial Locations

Locations (1)

Department of Anesthesiology, University Medical Center Hamburg-Eppendorf; 🇩🇪 Hamburg, Germany