NIRS vs TCD for Cerebrovascular Autoregulation During Non-cardiac Surgery (SONICA)

Cerebrovascular Autoregulation During Major Non-cardiac Surgery - a Comparison Between Near Infrared Spectroscopy and Transcranial Doppler Sonography

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.

Study Overview

• Status: Completed
• Conditions: Cerebrovascular Circulation
• Intervention / Treatment: Other: Continuous assessment of cerebrovascular autoregulation with NIRS and TCD

• Study Type: Observational
• Enrollment (Actual): 509

Contacts and Locations

Study Locations

• Germany
  • Hamburg, Germany, 20246
    • Department of Anesthesiology, University Medical Center Hamburg-Eppendorf

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 99 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients scheduled for non-cardiac surgery with general anesthesia at a tertiary care hospital

Description

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 Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

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

Secondary Outcome Measures

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

Collaborators and Investigators

• Sponsor: Universitätsklinikum Hamburg-Eppendorf
• Investigators: Principal Investigator: Marlene Fischer, MD, PhD, Universitatsklinikum Hamburg-Eppendorf

Study record dates

Study Major Dates

• Study Start (Actual): August 9, 2021
• Primary Completion (Actual): September 29, 2023
• Study Completion (Actual): September 19, 2024

Study Registration Dates

• First Submitted: July 18, 2021
• First Submitted That Met QC Criteria: July 18, 2021
• First Posted (Actual): July 27, 2021

Study Record Updates

• Last Update Posted (Estimated): October 2, 2025
• Last Update Submitted That Met QC Criteria: September 28, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: near-infrared spectroscopy; postoperative delirium; postoperative neurocognitive disorders; non-cardiac surgery; transcranial Doppler sonography
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Mental Disorders; Postoperative Complications; Pathologic Processes; Confusion; Neurobehavioral Manifestations; Neurocognitive Disorders; Delirium; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Emergence Delirium; Investigative Techniques; Diagnostic Techniques and Procedures; Diagnosis; Diagnostic Imaging; Chemistry Techniques, Analytical; Spectrum Analysis; Spectroscopy, Near-Infrared
• Other Study ID Numbers: SONICA

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No