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NCT Number: NCT07533370

Extended Emergence Strategy on Post-Anesthesia Care Unit Events After Outpatient Orthopedic Surgery

The goal of this clinical trial is to learn if an extended emergence from anesthesia can improve recovery room (Post-Anesthesia Care Unit or PACU) outcomes in lower-leg or foot surgery with nerve blocks. The primary questions it aims to answer are:

* Does a longer wake-up help participants think more clearly soon after surgery compared with usual approaches? * Does it lower pain scores, lower the amount of pain medications used, and shorten the time it takes to go home from recovery room?

Researchers will compare 2 groups of adults who are having similar lower-extremity orthopaedic surgeries with regional and propofol anesthesia.

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Key information

Conditions

Perioperative Care Confusion Delirium Delirium - Postoperative EEG Power Spectra Emergence Delirium Mental Disorders Nervous System Diseases Neurobehavioral Manifestations Neurocognitive Disorders Neurologic Manifestations Pathologic Processes Pathological Conditions, Signs and Symptoms Postoperative Complications Signs and Symptoms

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Stanford Medicine Outpatient Center

Redwood City, California, 94063, United States

Location contact

Harrison S Chow, MD, Msc.

PRINCIPAL_INVESTIGATOR

Makoto Kawai, MD, Dsc.

SUB_INVESTIGATOR

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Participants with American Society of Anesthesiologists (ASA) physical status I-III
  • Scheduled for Elective Foot/Ankle Orthopaedic surgery at Stanford Health under planned propofol-based intravenous anesthesia and regional nerve block for preoperative analgesia
  • Able and willing to complete all cognitive assessments and Brice Interview in PACU

Exclusion criteria

  • ASA physical status IV or V
  • Chronic opioid therapy
  • Chronic benzodiazepine use or ongoing treatment with strongly anticholinergic medications within 30 days prior to surgery.
  • Known major neuro-cognitive disorder, active psychotic disorder, or other severe psychiatric condition that, in the opinion of the investigator, would interfere with valid cognitive testing.
  • Active cardiac or neurological stimulators or pumps in use
  • Severe uncorrected visual or hearing impairment that precludes valid cognitive battery or interview completion.
  • Inability to speak and understand the study language sufficiently to provide informed consent and complete study assessments.
  • Inability to provide informed consent or lack of a legally authorized representative when required.
  • Concurrent participation in another interventional study that could confound PACU cognitive or delirium outcomes.

Treatment and study plan

Standard of Care EEG-Guided Emergence

Procedure

Participants in this arm will undergo standard-of-care emergence from general anesthesia, with anesthetic management and timing of emergence determined by the treating anesthesiologist according to usual institutional practice. Continuous frontal EEG monitoring will be available as part of routine intraoperative monitoring; however, anesthetic discontinuation, adjustment of anesthetic dose, and timing of tracheal extubation will not follow a protocolized extended EEG target (for example, there is no requirement to maintain PSI greater than 50 for a predefined duration before extubation).

Extended EEG Emergence Trajectory

Procedure

Participants receive protocolized extended emergence guided by continuous frontal EEG monitoring during the final phase of anesthesia. Anesthesiologists will titrate anesthetic dosing to achieve and maintain a pre-specified emergence EEG pattern characterized by a persistent, organized posterior-dominant beta rhythm and return of higher-frequency activity, corresponding to a Patient State Index (PSI) greater than 50 for at least 5 consecutive minutes before tracheal extubation. Standard intraoperative hemodynamic and respiratory management will be maintained per routine care.

Primary outcomes

  1. Time to Meet Post Anesthesia Care Unit (PACU) Discharge Criteria

    Time frame: Up to 2-5 hours post-surgery with discharge criteria are met.

    Study will measure time in minutes from PACU arrival to the first documentation of institutional PACU discharge criteria being met.

Secondary outcomes

  1. Change in Trail Making Test (TMT) time to completion

    Time frame: preoperative baseline (at arrival to pre-induction floor) to early postoperative PACU assessment (within 2 hours of PACU arrival)

    TMT Parts A and B is administered preoperatively and again in the early postoperative PACU period to assess attention, processing speed, and executive function. The outcome is the change in completion time (seconds) for TMT-A and TMT-B between postoperative and preoperative assessments (postoperative minus preoperative), with higher values indicating slower performance and worse cognitive function.

  2. Change in Digit Symbol Substitution Test (DSST) performance

    Time frame: preoperative baseline (at arrival to pre-induction floor) to early postoperative PACU assessment (within 2 hours of PACU arrival)

    DSST will be administered preoperatively and postoperatively in the PACU to assess psychomotor speed, attention, and working memory. The outcome is the change in number of correctly matched symbols between postoperative and preoperative assessments (postoperative minus preoperative), with negative values indicating a decline in performance.

  3. Pain intensity during PACU stay measured by Numeric Rating Scale (NRS)

    Time frame: From PACU arrival to discharge in 15 minute increments (within 24 hours)

    Pain intensity will be assessed using an 11-point Numeric Rating Scale (NRS; 0 = no pain, 10 = worst imaginable pain) during the PACU stay.

  4. Total opioid consumption in the PACU in morphine milligram equivalents

    Time frame: From PACU arrival to pre-induction until PACU discharge (up to 24 hours)

    All opioid medication dosages will be converted to morphine milligram equivalents (MME) using standard equianalgesic conversion factors, and summed to obtain the total opioid consumption per participant during the PACU stay.

  5. Incidence of dreaming assessed by modified Brice questionnaire

    Time frame: Within 5 minutes of arrival into PACU

    A modified Brice questionnaire will be administered after anesthesia to assess intraoperative dreaming, including any explicit recall of events and reports of dream experiences.

  6. Incidence of awareness assessed by modified Brice questionnaire

    Time frame: Within 5 minutes of arrival into PACU

    A modified Brice questionnaire will be administered after anesthesia to assess intraoperative awareness, including any explicit recall of events and reports of dream experiences.

Sponsors and collaborators

Lead sponsor

Harrison Shong-Wen Chow

Other

Registry information

Official study title

Extended Emergence Trajectory on Post-Anesthesia Care Units Events in Ambulatory Lower-Extremity Orthopedic Surgery: A Randomized Controlled Trial

Acronym: PACU-EMERGE

Important dates

Study start
2026
Primary completion
2027
Study completion
2027
First posted
Apr 16, 2026
Registry last updated
May 22, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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