Processed Electroencephalography-guided General Anesthesia and Outcomes in Major Abdominal Surgery

Impact of Reduced Intraoperative Norepinephrine Requirements Via Processed Electroencephalography-Guided General Anesthesia on Patient Outcomes After Major Abdominal Surgeries

This study aims to evaluate whether the reduction in the amount of intraoperative norepinephrine required to prevent hypotension, facilitated by processed electroencephalography (pEEG) -guided general anesthesia, will lead to a decrease in postoperative complications, particularly acute kidney injury (AKI).

Study Overview

• Status: Recruiting
• Conditions: Postoperative Acute Kidney Injury
• Intervention / Treatment: Device: Processed electroencephalography (pEEG) Guided General Anesthesia; Device: Non-pEEG-Guided General Anesthesia (with blinded pEEG monitoring)

Detailed Description

In major abdominal surgery, intraoperative hypotension (IOH) remains a prevalent concern, contributing significantly to postoperative complications. These complications include acute kidney injury (AKI), myocardial injury, and even mortality. While IOH is multifactorial, its occurrence is frequently associated with the need for vasopressor support, particularly norepinephrine, which is widely used to manage and prevent IOH. However, it is important to note that vasopressors, including norepinephrine, are themselves implicated in promoting AKI .

The lack of consensus on a universal definition for IOH adds complexity to this issue. Currently, it remains unclear whether IOH should be defined based on absolute blood pressure thresholds or as a relative decrease from baseline. IOH is commonly defined as a systolic blood pressure of <90 mm Hg or a mean arterial pressure (MAP) of <65 mm Hg.

Ephedrine is often the first-line vasopressor administered to treat IOH, with norepinephrine as a second-line option. The hemodynamic effects of these two agents differ: norepinephrine increases cardiac preload without significantly increasing afterload, thereby raising cardiac output. Ephedrine, however, increases cardiac output but with a greater increase in afterload, often leading to tachycardia, which can be detrimental to patients. The variable effectiveness of ephedrine and its associated side effects have led clinicians to consider norepinephrine as a more appropriate option for managing IOH, potentially with fewer cardiovascular side effects.

Additionally, crystalloid fluid overload during abdominal surgery has been linked to poor postoperative outcomes, including anastomotic instability. Liberal fluid regimes may disrupt the physiological healing processes at surgical sites, suggesting that fluid management strategies aimed at minimizing overload could improve patient outcomes.

Recent studies propose that early norepinephrine administration to maintain MAP, even before the onset of hypotension, may help reduce the need for large fluid volumes.

One important factor contributing to IOH and vasopressor use is excessively deep general anesthesia. Processed electroencephalography (pEEG) can guide the optimization of anesthesia depth, potentially preventing overly deep anesthesia and, in turn, reducing the incidence of IOH and the need for vasopressor .

• Study Type: Interventional
• Enrollment (Estimated): 162
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Walaa H Mohamed, Assistant Lecturer; Phone Number: +201061403338; Email: walaa95.hamdy@gmail.com
• Study Contact Backup: Name: Mostafa S Abbas, Professor; Phone Number: +201003060187; Email: mostafasamy@aun.edu.eg

Study Locations

• Egypt
  • Assiut, Egypt
    • Recruiting
    • Assiut University Hospitals
    • Contact: Vice president of graduate studies of Assiut University; Phone Number: +2088 22080; Email: vp_grad@aun.edu.eg
    • Contact: Walaa H Mohamed, Assistant Lecturer

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Patients scheduled for major abdominal surgery lasting more than 2 hours under general anesthesia.
2. American Society of Anesthesiologists Physical Status (ASA) score I-III.
3. Age range of 18-70 years.
4. Both male and female patients.

Exclusion Criteria:

1. Emergency surgeries.
2. Uncontrolled hypertension (systolic blood pressure >150 mm Hg) despite medication.
3. Recent acute cardiovascular events, including heart failure or acute coronary syndrome.
4. Chronic kidney disease with a glomerular filtration rate <30 ml/min/1.73 m² or requiring renal replacement therapy.
5. Severe hepatic failure (ASAT/ALAT >2N, elevated bilirubin, or PT <50%).
6. Preoperative sepsis or septic shock.
7. Pregnancy.
8. Patient refusal to participate in the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: pEEG-Guided General Anesthesia Group; Depth of anesthesia will be managed based on pEEG monitoring using Entropy with a target range of 40-60.	Device: Processed electroencephalography (pEEG) Guided General Anesthesia; Processed electroencephalography (pEEG) can guide the optimization of anesthesia depth, potentially preventing overly deep anesthesia and, in turn, reducing the incidence of IOH and the need for vasopressors . Depth of anesthesia will be managed based on pEEG monitoring using Entropy with a target range of 40-60.
Placebo Comparator: Non-pEEG-Guided Anesthesia (Standard Care Group) with blinded pEEG monitoring; Depth of anesthesia will be managed based on clinical judgment, informed by clinical perception and vital signs.	Device: Non-pEEG-Guided General Anesthesia (with blinded pEEG monitoring); Depth of anesthesia will be managed based on clinical judgment, informed by clinical perception and vital signs.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of postoperative acute kidney injury (AKI) based on the KDIGO criteria.	Diagnosis and severity of PO-AKI will be assessed by serum-creatinine and/or urine output according to the KDIGO criteria . The latest serum creatinine before surgery will be defined as baseline value. Serum creatinine will be measured at least once a day for the first 3 days. Patients with serum creatinine increases of ≥0.3 mg/dl within 48 h or 1.5-1.9 times increases within 72 h after surgery will be diagnosed KDIGO stage 1, patients with serum creatinine increases of 2-2.9 times within 72 h will be diagnosed KDIGO stage 2, and patients with serum creatinine increases of ≥3 times or ≥4 mg/dl or with the need of renal replacement therapy (RRT) will be diagnosed KDIGO stage 3. Further, patients with a urine out- put <0.5 ml/kg/h for ≥6 h will be diagnosed KDIGO stage 1, urine output <0.5 ml/kg/h for ≥12 h KDIGO stage 2, and <0.3 ml/kg/h for ≥24 h or anuria for ≥12 h KDIGO stage 3. Once the urine catheter removed, the urine output criterion will no longer be considered.	Assessed at the third postoperative day.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
1.Total dose of norepinephrine administrated	The total cumulative dose of norepinephrine administered intraoperatively and postoperatively will be recorded in micrograms.	48 hour
2.The volume of intraoperative fluid therapy.	The volume of crystalloids, colloids, and blood products administered intraoperatively will be recorded in (milliliters).	48 hour

Collaborators and Investigators

• Sponsor: Assiut University

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2025
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): January 1, 2027

Study Registration Dates

• First Submitted: December 10, 2024
• First Submitted That Met QC Criteria: December 21, 2024
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: February 2, 2025
• Last Verified: February 1, 2025

More Information

Terms related to this study

• Keywords: Hypotension; Norepinephrine; Acute kidney injury; Abdominal surgery
• Additional Relevant MeSH Terms: Urogenital Diseases; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Renal Insufficiency; Acute Kidney Injury; Physiological Effects of Drugs; Central Nervous System Depressants; Anesthetics
• Other Study ID Numbers: EEG-Guided General Anesthesia

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