Cerebrovascular Circulation
Conditions
Keywords
postoperative neurocognitive disorders, postoperative delirium, near-infrared spectroscopy, transcranial Doppler sonography, non-cardiac surgery
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.
Interventions
OTHERContinuous assessment of cerebrovascular autoregulation with NIRS and TCD
Continuous monitoring of MAP, cerebral oxygenation, and cerebral blood flow velocity before, during, and after surgery to calculate two cerebrovascular autoregulation indices Cox and Mx.
Sponsors
Universitätsklinikum Hamburg-Eppendorf
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 99 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| length of hospital stay | date of discharge from hospital (up to 30 days) | duration of hospital stay (in days) between surgery and discharge |
| optimal MAP during TCD-based measurement of cerebrovascular autoregulation | up to 4 hours during surgery | MAP at lowest cerebral autoregulation index (Mx) |
| mortality at 3 months after surgery | 3 months after surgery | survival status three months after surgery |
| 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 |
| 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 |
Countries
Germany
Outcome results
None listed