Brain Monitors to Reduce Child Confusion After Anesthesia

The Role of BIS-Guided Anesthesia in Reducing Emergence Delirium in Children (Çocuklarda Derlenme Deliryumunun Azaltılmasında BİS Kılavuzluğunda Anestezi)

The goal of this clinical trial was to learn if using a brain monitor to adjust anesthesia (sleep medicine) during surgery could prevent emergence delirium (severe confusion and agitation upon waking) in children aged 2 to 12 years having their tonsils or adenoids removed. The main questions it aimed to answer were:

Did using a brain monitor lower the chance of children waking up confused and upset?

Did using the brain monitor reduce the amount of anesthesia gas (sevoflurane) needed during surgery, and did it affect recovery time or pain levels?

Researchers compared anesthesia adjusted using a bispectral index (BIS) brain monitor to anesthesia adjusted using standard care to see if the brain monitor lowered the chance of emergence delirium.

Participants in the study:

Received general anesthesia (a standardized mix of inhaled and intravenous medicines, including sevoflurane and fentanyl) to safely sleep through surgery to remove their tonsils or adenoids

Had the dose of their main anesthesia gas (sevoflurane) adjusted during surgery based on either brain monitor readings (targeting a specific sleep depth of 40-60) or standard physical responses (like heart rate and blood pressure)

Were checked by the research team immediately after waking up to measure their confusion, agitation, and pain using standard clinical rating scales

Study Overview

• Status: Completed
• Conditions: Emergence Delirium (Derlenme Deliryumu)
• Intervention / Treatment: Device: BIS-Guided Anesthesia; Drug: Standard Care Anesthesia

Detailed Description

Emergence delirium (ED) represents a significant neurobehavioral complication that frequently occurs during the immediate postoperative period in pediatric populations, particularly following otorhinolaryngological procedures such as adenoidectomy and tonsillectomy. Characterized by severe agitation, altered awareness, disturbed psychomotor behavior, and inconsolability, ED poses safety risks to the recovering patient and increases the burden on healthcare providers and caregivers. While the etiology of ED is multifactorial, the intraoperative depth of anesthesia and the cumulative exposure to specific volatile anesthetics, such as sevoflurane, are known modifiable risk factors. Both excessively deep and inadequately light anesthesia can contribute to poor recovery profiles. The Bispectral Index (BIS) is an electroencephalogram (EEG)-based monitor that provides an objective measurement of a patient's level of consciousness, allowing anesthesiologists to precisely titrate anesthetic agents to an optimal depth.

This prospective, randomized controlled study was designed to investigate the role of BIS-guided anesthetic titration in mitigating the risk of ED. Upon enrollment, pediatric patients undergoing adenoidectomy and/or tonsillectomy were randomized into one of two clinical care pathways: a BIS-guided anesthesia group or a standard-care group.

To ensure baseline consistency across the study, all participants followed a standardized anesthetic induction protocol. Following routine premedication, general anesthesia was induced using inhaled sevoflurane combined with intravenous lidocaine, rocuronium (for muscle relaxation), and fentanyl (for analgesia). For the maintenance phase of anesthesia, patients in both arms received a combination of inhaled sevoflurane and continuous remifentanil infusions.

The critical divergence in the study protocol occurred during the intraoperative maintenance phase:

BIS-Guided Pathway: Anesthesiologists continuously monitored the patient's EEG activity using the BIS monitor. The concentration of the sevoflurane gas was deliberately titrated to maintain a BIS value between 40 and 60, which represents an optimal and safe depth for surgical anesthesia. By keeping patients within this precise target range, the protocol systematically avoided periods of excessively deep (BIS < 40) or overly light (BIS > 60) anesthesia.

Standard-Care Pathway: Anesthesiologists adjusted the sevoflurane concentrations based entirely on traditional clinical signs and autonomic responses, specifically monitoring hemodynamic fluctuations such as heart rate and blood pressure, without the use of EEG-guided depth parameters.

Following the completion of the surgical procedure, patients were transferred to the post-anesthesia care unit (PACU) for close observation. The clinical team systematically evaluated the patients' transition from unconsciousness to wakefulness. To ensure a robust, multi-faceted assessment of neurobehavioral status, the clinical staff utilized three validated behavioral assessment tools: the Pediatric Anesthesia Emergence Delirium (PAED) scale, the Watcha scale, and the Cravero scale. Simultaneously, postoperative physical pain was managed and tracked using the Face, Legs, Activity, Cry, Consolability (FLACC) behavioral scale.

If a patient exhibited signs meeting predetermined thresholds for severe emergence delirium (specifically, a PAED score of 10 or higher, a Watcha score of 3 to 4, or a Cravero score of 4 or higher), the clinical protocol dictated the administration of intravenous fentanyl as a rescue pharmacological intervention to safely manage the agitation.

Through this methodology, the study sought to define the relationship between strict, brain-monitored anesthetic titration and postoperative behavior. It comprehensively evaluated how preventing fluctuations in anesthetic depth impacts overall volatile anesthetic consumption, the necessity for rescue opioids in the recovery room, and the overall quality and speed of pediatric recovery following airway surgery.

• Study Type: Interventional
• Enrollment (Actual): 125
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Ankara, Turkey (Türkiye)
    • Baskent University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Children between the ages of 2 and 12 years
• Scheduled for a planned surgery to remove adenoids, tonsils, or both
• Generally healthy or having only mild medical conditions (American Society of Anesthesiologists class I or II)
• Expected to have a surgery that lasts less than 4 hours
• Having the procedure as an outpatient and expected to go home the same day

Exclusion Criteria:

• Having severe medical conditions (American Society of Anesthesiologists class III or IV)
• Having a known history of neurological or psychiatric diseases
• Diagnosed with a developmental delay
• Having severe heart, lung, or metabolic conditions
• Having a known allergy to any of the medications used in the study
• Parents or legal guardians refuse to provide written consent to participate

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: BIS-Guided Anesthesia; This group received the specific intervention (the BIS monitor to guide anesthesia depth) that is the main focus of your research study.	Device: BIS-Guided Anesthesia; Anesthetic depth was continuously guided by the Bispectral Index (BIS) monitor. A single-use BIS sensor was placed on the patient's forehead before anesthesia induction to record real-time EEG activity. The primary inhaled anesthetic (sevoflurane) was continuously titrated throughout the surgery to strictly maintain a BIS value within the target range of 40 to 60. If the BIS value dropped below 40, the sevoflurane concentration was decreased. If the BIS value exceeded 60, the continuous remifentanil infusion (0.02-0.1 mcg/kg/min) was increased first, followed by an increase in sevoflurane if necessary. Intervention
Active Comparator: Standard Care Anesthesia; This group received the standard, established method of care (titrating anesthesia based on heart rate and blood pressure).	Drug: Standard Care Anesthesia; Anesthetic depth was guided solely by traditional clinical signs and autonomic responses. The primary inhaled anesthetic (sevoflurane) was initiated at a 1% end-tidal concentration and adjusted in 0.25% increments (range 0.50% to 1.5%) to maintain the patient's heart rate and blood pressure within ±25% of their baseline pre-anesthesia values. Remifentanil was also infused continuously (0.02-0.1 mcg/kg/min) and adjusted based on clinical requirements. A BIS sensor was attached to the patient to record data, but the monitor screen was completely blinded to the anesthesia care provider, ensuring titration relied exclusively on standard hemodynamic metrics.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Primary Outcome Measure 1: Incidence of Emergence Delirium Assessed by the PAED Scale	Evaluated postoperatively using the Pediatric Anesthesia Emergence Delirium (PAED) scale. The scale ranges from a minimum of 0 to a maximum of 20. Higher scores mean a worse outcome (more severe delirium). Scores of 10 or higher were classified as a positive diagnosis for emergence delirium.	Postoperative minutes 5, 10, 15, 30, 45, and 60 following extubation.
Primary Outcome Measure 2: Incidence of Emergence Delirium Assessed by the Watcha Scale	Evaluated postoperatively using the Watcha behavioral scale. The scale ranges from a minimum of 1 to a maximum of 4. Higher scores mean a worse outcome (greater agitation and delirium). Scores of 3 to 4 were classified as a positive diagnosis for emergence delirium.	Postoperative minutes 5, 10, 15, 30, 45, and 60 following extubation.
Primary Outcome Measure 3: Incidence of Emergence Delirium Assessed by the Cravero Scale	Evaluated postoperatively using the Cravero behavioral scale. The scale ranges from a minimum of 1 to a maximum of 5. Higher scores mean a worse outcome (greater agitation). Scores of 4 or higher were classified as a positive diagnosis for emergence delirium.	Postoperative minutes 5, 10, 15, 30, 45, and 60 following extubation.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total Sevoflurane Consumption	The total volume of sevoflurane anesthetic gas consumed during the surgical procedure was measured in milliliters (mL).	Intraoperative (From anesthesia induction until the completion of surgery).
Postoperative Pain Assessed by the FLACC Scale	Assessed using the Face, Legs, Activity, Cry, Consolability (FLACC) behavioral scale. The scale ranges from a minimum of 0 to a maximum of 10. Higher scores mean a worse outcome (more severe pain). Scores of 4 or higher indicated the presence of pain.	Postoperative minutes 5, 10, 15, 30, 45, and 60 following extubation.
Rescue Opioid Usage	Administration of intravenous rescue fentanyl (administered at a dose of 1-2 mcg/kg) as an intervention for severe emergence delirium or inadequate pain control.	Up to 60 minutes during the post-anesthesia recovery period.
Recovery Time	Time required to meet safe discharge criteria from the post-anesthesia care unit, determined by the Modified Aldrete Score. The scale ranges from 0 to 10; higher scores mean a better outcome. A score of 9 or higher indicates readiness for discharge.	Up to 4 hours (From transfer to the recovery unit until discharge criteria were successfully met).

Collaborators and Investigators

• Sponsor: Baskent University

Study record dates

Study Major Dates

• Study Start (Actual): August 8, 2025
• Primary Completion (Actual): November 21, 2025
• Study Completion (Actual): November 21, 2025

Study Registration Dates

• First Submitted: August 4, 2026
• First Submitted That Met QC Criteria: September 15, 2026
• First Posted (Actual): September 17, 2026

Study Record Updates

• Last Update Posted (Actual): September 17, 2026
• Last Update Submitted That Met QC Criteria: September 15, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Keywords: tonsillectomy; emergence delirium; pediatric anesthesia; adenoidectomy; bispectral index; anesthetic depth
• 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
• Other Study ID Numbers: KA24/328

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No