Processed EEG Monitoring During Controlled Hypotension in Patients Undergoing Rhinoplasty

June 25, 2026 updated by: Elif KARAKAYA, Gazi University

Observational Evaluation of the Relationship Between Intraoperative Processed EEG Monitoring,Surgical Bleeding and Recovery Quality in Patients Undergoing Rhinoplasty Under Controlled Hypotension

This prospective observational study evaluates intraoperative processed electroencephalography parameters in adult patients undergoing elective rhinoplasty under total intravenous anesthesia with controlled hypotension. The study focuses on qCON and qNOX values during anesthesia, their relationship with early postoperative recovery, and their association with intraoperative surgical bleeding and surgical field quality.

Study Overview

Status

Completed

Conditions

Detailed Description

Controlled hypotension is commonly used during rhinoplasty to improve surgical field visibility and reduce bleeding. However, the adequacy and safety of controlled hypotension should not be evaluated only by hemodynamic variables. Processed EEG monitoring may provide additional information about hypnotic depth and the probability of response to nociceptive stimulation.

In this prospective observational study, adult patients undergoing elective rhinoplasty under general anesthesia were monitored with standard ASA monitoring and processed EEG monitoring. Total intravenous anesthesia was maintained with propofol and remifentanil. Esmolol infusion was used as part of the controlled hypotension strategy. Intraoperative qCON and qNOX values, hemodynamic parameters, surgical bleeding scores, anesthetic drug consumption, extubation time, time to reach Aldrete score ≥9, and early postoperative cognitive recovery were recorded.

The primary objective is to evaluate the intraoperative course of qCON and qNOX values during controlled hypotension. Secondary objectives are to assess the relationship of processed EEG parameters with recovery quality, early postoperative cognitive status, anesthetic drug consumption, and surgical field bleeding.

Study Type

Observational

Enrollment (Actual)

64

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Adult patients scheduled for elective rhinoplasty under general anesthesia at Gazi University Faculty of Medicine were included in this prospective observational study. All patients underwent total intravenous anesthesia with esmolol-supported controlled hypotension and intraoperative processed EEG monitoring. Hemodynamic parameters, qCON and qNOX values, surgical bleeding scores, anesthetic drug consumption, and early postoperative recovery outcomes were recorded.

Description

Inclusion Criteria:

  • Patients aged 18 years or older
  • Patients scheduled for elective rhinoplasty
  • Patients classified as ASA physical status I-II
  • Patients planned to undergo general anesthesia with total intravenous anesthesia
  • Patients in whom frontal processed EEG electrodes can be applied
  • Patients who provide written informed consent

Exclusion Criteria:

  • Emergency surgery
  • Severe neurological disease
  • Scalp lesion or marked dermatitis preventing processed EEG electrode placement
  • Communication or hearing impairment preventing postoperative assessment
  • Marked hemodynamic instability
  • Multiple trauma or need for postoperative intensive care unit admission
  • Pregnancy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Intraoperative qCON and qNOX values during controlled hypotension
Time Frame: From baseline before anesthesia induction until the end of surgery, up to approximately 150 minutes intraoperatively.
qCON and qNOX values obtained by processed EEG monitoring will be recorded at predefined intraoperative time points. qCON will be used as an index of hypnotic depth, and qNOX will be used as an index of the probability of response to nociceptive stimulation.
From baseline before anesthesia induction until the end of surgery, up to approximately 150 minutes intraoperatively.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Heart rate during controlled hypotension
Time Frame: From baseline before anesthesia induction until the end of surgery, up to approximately 150 minutes intraoperatively.
Heart rate will be recorded at predefined intraoperative time points to evaluate hemodynamic stability.
From baseline before anesthesia induction until the end of surgery, up to approximately 150 minutes intraoperatively.

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Surgical field bleeding score
Time Frame: Intraoperatively, from surgical incision until the end of surgery.
Surgical field bleeding will be evaluated using the Boezaart surgical field bleeding score at predefined intraoperative time points.
Intraoperatively, from surgical incision until the end of surgery.
Extubation time
Time Frame: At the end of surgery
Time from discontinuation of anesthetic agents to extubation will be recorded in minutes
At the end of surgery
Time to reach Aldrete score ≥9
Time Frame: Early postoperative recovery period, immediately after extubation.
The time required to reach an Aldrete recovery score of 9 or higher will be recorded in minutes
Early postoperative recovery period, immediately after extubation.
Early postoperative delirium assessed by the Nursing Delirium Screening Scale
Time Frame: At admission to the post-anesthesia care unit
Patients were assessed for early postoperative delirium in the post-anesthesia care unit using the Nursing Delirium Screening Scale (Nu-DESC). The Nu-DESC ranges from 0 to 10, with higher scores indicating more severe delirium symptoms.
At admission to the post-anesthesia care unit
Total anesthetic drug consumption
Time Frame: From anesthesia induction until the end of surgery
Total intraoperative consumption of propofol, remifentanil, and esmolol will be recorded
From anesthesia induction until the end of surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Gazi University

Investigators

  • Study Chair: Nurdan Bedirli, MD, Gazi University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 1, 2025

Primary Completion (Actual)

February 25, 2026

Study Completion (Actual)

February 25, 2026

Study Registration Dates

First Submitted

June 20, 2026

First Submitted That Met QC Criteria

June 25, 2026

First Posted (Actual)

June 26, 2026

Study Record Updates

Last Update Posted (Actual)

June 26, 2026

Last Update Submitted That Met QC Criteria

June 25, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • 172

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared due to institutional and ethical restrictions and to protect participant confidentiality.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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