Effect of EEG-guided General Anesthesia on Cumulative Dose of Norepinephrine

Universitätsklinikum Hamburg-Eppendorf

Status: Completed

Conditions: Hypotension

Treatments: Device: EEG-guided general anesthesia

Study type: Interventional

Funder types: Other

Identifiers

NCT05293288

2020-10155-BO-ff

Details and patient eligibility

About

Intraoperative hypotension is common in patients having non-cardiac surgery under general anesthesia and is associated with major postoperative complications including myocardial injury, AKI, and death.

Intraoperative hypotension is also common in patients having vascular surgery. To treat intraoperative hypotension, vasopressors - such as norepinephrine - and fluids are used. However, high-dose vasopressor and excessive fluid therapy are also associated with postoperative complications.

The depth of general anesthesia may be a modifiable cause of intraoperative hypotension. Deep levels of general anesthesia may cause cardiovascular depression with intraoperative hypotension and higher vasopressor requirements. Optimal depth of general anesthesia is defined as a state in which the patient is at low risk of recall of intraoperative events while maintaining blood pressure stability with minimal intervention.

Depth of anesthesia can be confirmed using clinical signs, the concentration of inhaled or intravenous anesthetics, or neuromonitoring such as processed electroencephalography (pEEG). pEEG presents an opportunity to monitor changes in human brain electrical activity and to help estimating the patients' level of (un)consciousness and the optimal depth of anesthesia. EEG-guided general anesthesia may thus decrease norepinephrine doses needed to treat intraoperative hypotension in patients having surgery.

Enrollment: 110 patients

Sex: All

Ages: 45+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion and exclusion criteria

We will include consenting patients ≥45 years scheduled for elective vascular surgery under general anesthesia if:

• surgery is expected to last at least 60 min AND
• the estimated blood loss during surgery is less than 1000 mL AND
• intraarterial blood pressure monitoring (arterial catheter) is planned during surgery

We will not include patients with previous transplantation of kidney, liver, heart, or lung and those who are septic (according to current Sepsis-3 definition). And we will not include patients with American Society of Anesthesiologists' physical status V and VI, or pregnancy.

We will exclude patients after randomization if they were treated with vasopressors others than norepinephrine during surgery.

Written informed consent will be obtained from all patients prior to study inclusion.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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110 participants in 2 patient groups

EEG-guided general anesthesia

Experimental group

Description:

EEG-guided general anesthesia group (i.e., intervention group): For pEEG monitoring we will use the SEDLine monitor (Masimo, Irvine, CA) which provides the patient state index (PSi; a processed EEG parameter with values from 1 to 100), density spectral array (DSA; a display that represents the frequencies and amplitudes of brain waves through time), spectral edge frequency (SEF), and the raw EEG signal.

Treatment:

Device: EEG-guided general anesthesia

Routine care

No Intervention group

Description:

Routine care group (i.e., control group): Adjustment of depth of general anesthesia will be at the discretion of the treating anesthesiologist.