Processed EEG-Guided Anesthesia: Study Characteristics from 96 Trials

paper country center_type enrollment_criteria sample_size_total sample_size_peeg sample_size_control intervention_description comparator_description anesthetic_agent manufacturer_brand funding_source age_mean_years_peeg age_sd_years_peeg age_median_years_peeg age_iqr_years_peeg age_mean_years_control age_sd_years_control age_median_years_control age_iqr_years_control female_percent_peeg female_percent_control asa_score_peeg asa_score_control asa_comment anesthesia_duration_is_surgery anesthesia_duration_mean_hours_peeg anesthesia_duration_sd_hours_peeg anesthesia_duration_median_hours_peeg anesthesia_duration_iqr_hours_peeg anesthesia_duration_mean_hours_control anesthesia_duration_sd_hours_control anesthesia_duration_median_hours_control anesthesia_duration_iqr_hours_control
1 ahmad2003 USA single Inclusion: Patients undergoing gynecologic laparoscopy; Exclusion: Patients requiring inpatient hospitalization postoperatively for surgical complications 97 49 48 BIS target 50–60, sevoflurane titration, nitrous oxide added after laparoscope removal to maintain BIS < 60 Clinical monitoring (HR/BP ±20% baseline); sevoflurane titration Sevoflurane & (Nitrous Oxide or null) & Sufentanil BIS/Bispectral Index (Aspect Medical Systems) Aspect Medical Systems 35.6 8.7 NR NR 35.4 8.9 NR NR 100 100 I-II I-II N/A Yes 1.15 0.62 NR NR 1.12 0.6 NR NR
2 akcal2008 Turkey single Inclusion: ASA I-II; aged 18–60; scheduled for lumbar discectomy; Exclusion: history of central nervous system disease (e.g., hearing loss, seizure disorders); chronic use of psychoactive medication; any clinically significant cardiovascular, renal, hepatic or endocrine disorder 56 28 28 BIS target 45-65, propofol/remifentanil titration Clinical monitoring (hemodynamic parameters); propofol/remifentanil titration; BIS recorded but blinded Propofol & Remifentanil A-2000 Bispectral index (Aspect Medical Systems) NR 39.7 11.2 NR NR 44.3 12.7 NR NR 67.9 53.6 I-II I-II N/A No 1.83 0.86 NR NR 2.11 0.8 NR NR
3 assareh2002 Sweden single Inclusion: Patients aged 18–65 years, ASA I–II, scheduled for elective knee arthroscopy; Exclusion: NR 60 30 30 A-line AEP index target 30±5, sevoflurane titration Clinical monitoring (Evan's score: HR, BP, tearing, sweating, respiration); sevoflurane titration Sevoflurane & Nitrous oxide A-line/AEP Monitor (Danmeter A/S) None 46 12 NR NR 51 11 NR NR NR NR I-II I-II N/A No 0.25 0.08 NR NR 0.28 0.12 NR NR
4 asthana2013 India single Inclusion: 20-60 years, ASA I and II, elective surgical procedure under general anesthesia with endotracheal intubation; Exclusion: history of stroke, stupor, dementia, long-term use of central nervous system (CNS) activator drugs, benzodiazepines and/or opiates therapy, pregnant females 70 35 35 BIS target 48±2, propofol titration Clinical monitoring (loss of response to verbal command); propofol titration Nitrous oxide & Isoflurane BIS monitor A-2000 (unspecified) None 32.69 12.7 NR NR 34.17 10.54 NR NR 48.6 51.4 I-II I-II N/A NR NR NR NR NR NR NR NR NR
5 avidan2008 USA single Inclusion: Adults >18 years; high risk for anesthesia awareness (e.g., substance use, EF <40%, history of awareness, difficult intubation, ASA 4-5, aortic stenosis, end-stage lung disease, open-heart surgery); general anesthesia with isoflurane, sevoflurane, or desflurane; Exclusion: Procedure preventing BIS monitoring; wake-up test required; dementia; inability to consent; history of stroke with deficits 1941 967 974 BIS target 40-60, isoflurane/sevoflurane/desflurane titration, audible alarms for BIS outside target range ETAG-guided anesthesia (0.7-1.3 MAC); volatile anesthetic titration, BIS recorded but blinded Isoflurane or Sevoflurane or Desflurane BIS/Bispectral Index (Aspect Medical Systems) Barnes-Jewish Hospital Foundation 59.5 14.8 NR NR 59.2 14.6 NR NR 46.6 46.3 I-IV I-IV No actual ASA V included NR NR NR NR NR NR NR NR NR
6 avidan2011 USA; Canada multi Inclusion: Patients 18 years of age or older undergoing elective surgery, high risk for intraoperative awareness (at least one risk factor), general anesthesia with isoflurane, sevoflurane, or desflurane; Exclusion: Dementia, unable to provide written informed consent, history of stroke with residual neurologic deficits 5713 2861 2852 BIS target 40-60, isoflurane, sevoflurane, or desflurane titration MAC-guided volatile anesthesia; ETAC target 0.7-1.3 MAC, BIS recorded but blinded Isoflurane or Sevoflurane or Desflurane BIS/Bispectral Index (Covidien) Foundation for Anesthesia Education and Research; American Society of Anesthesiologists; Winnipeg Regional Health Authority; University of Manitoba Department of Anesthesia 60 14.2 NR NR 61 14.4 NR NR 43.3 41.1 I-IV I-IV N/A NR NR NR NR NR NR NR NR NR
7 basar2003 Turkey single Inclusion: ASA I and II; open abdominal surgery. Exclusion: renal, hepatic or neurological dysfunction; use of benzodiazepines, anticonvulsants, alcohol, opioids or other psychotrophic drugs. 60 30 30 BIS target 40-60, sevoflurane titration Clinical monitoring; sevoflurane titration; BIS recorded but blinded Sevoflurane & Nitrous oxide Aspect A-2000 (Aspect Medical Systems) NR 42.1 3.3 NR NR 39 4.5 NR NR 56.7 60 I-II I-II N/A No 1.42 0.18 NR NR 1.51 0.15 NR NR
8 bauer2004 Germany single Inclusion: elective coronary artery bypass grafting (CABG); Exclusion: history of previous cardiac surgery; concomitant congestive (ejection fraction < 40%; New York Heart Association grades III and IV) or valvular heart disease; myocardial infarction during the last 3 months; evidence of coexisting malignant or immunologic diseases; diabetic patients; significant renal (creatinine > 1.5 mg%) or hepatic dysfunction (aspartate amino transferase, alanine amino transferase > 50% over normal range) 40 20 20 Aspect A-2000 BIS target 40-50, propofol/remifentanil titration TCI-guided (Marsh model); propofol titration Propofol & Remifentanil A-2000 BIS/Bispectral Index (Aspect Medical Systems) Else Kröner-Fresenius Foundation NR NR 60 NR NR NR 61 NR NR NR NR NR N/A Yes NR NR 4.12 NR NR NR 4.05 NR
9 budania2017 India single Inclusion: age 20-60 years, ASA I and II, BMI 18-25 kg/m2, undergoing elective abdominal hysterectomy under GA using endotracheal tube; Exclusion: sedatives/hypnotics preoperatively, hemodynamically unstable, altered sensorium, hypothermic, psychiatric illness/alcohol abuse 60 30 30 Entropy score target 40-60, isoflurane titration Clinical monitoring (HR/BP and MAC 1-1.3); isoflurane titration; entropy recorded but blinded Isoflurane & Nitrous Oxide Spectral Entropy (GE Healthcare) None 42.67 6.477 NR NR 44.33 6.799 NR NR 100 100 I-II I-II N/A Yes 2.155 0.22 NR NR 2.112 0.222 NR NR
10 centimole2019 USA single Inclusion: aged 45 to 70 years; ASA classes 1 through 4; scheduled for surgeries requiring general endotracheal anesthesia with a neuromuscular paralytic agent; lasting approximately 2 hours; successful completion of Motor Screening Task; Exclusion: substantial cardiorespiratory or other end-organ disease; inadequate English; substance abuse; preexisting neurologic diseases; neurosurgical candidates 79 39 40 BIS target 45-60, sevoflurane/desflurane/isoflurane titration, but not less than 0.5 age-adjusted MAC Clinical monitoring (titrated around MAC values); sevoflurane/desflurane/isoflurane titration; BIS recorded but blinded Desflurane or Isoflurane or Sevoflurane BIS/Bispectral Index (Covidien, now Medtronic) AANA Foundation; National Institutes of Health; National Institute of Nursing Research 59.6 6.8 NR NR 58.5 6.4 NR NR 61.5 65 II-III II-III Inclusion criteria states ASA I-IV, but only ASA II and III were included. No 3.45 0.95 NR NR 3.53 0.98 NR NR
11 chan2013 Hong Kong multi Inclusion: ≥60 years, elective major surgery expected to last ≥2 hours, anticipated hospital stay ≥4 days; Exclusion: Illiteracy, language difficulties, significant hearing or visual impairment, major psychosis, CNS disease, dementia or MMSE ≤23 902 450 452 BIS target 40-60, propofol/volatile anesthetics titration Clinical monitoring (MAP +/- 15mmHg baseline, HR 40-90 bpm); clinical signs/hemodynamic titrated anesthetic; BIS recorded but blinded Propofol or (Volatile & (Nitrous Oxide or null)) BIS / A-2000 System XP (Covidien/Medtronic) Competitive Earmarked Research Grant; Research Grants Council of Hong Kong; Health and Health Services Research Fund 68.1 8.2 NR NR 67.6 8.3 NR NR 37.8 39.6 I-IV I-IV Reported as grouped categories 1-2 and 3-4 No 2.1 1 NR NR 2 1.1 NR NR
12 chaudhuri2022 India single Inclusion: ASA physical status I and II; aged 18–60 years; undergoing elective surgical procedures requiring general anaesthesia; Exclusion: history of long-term use of anticonvulsants, opiates, benzodiazepines, cocaine, alcohol; pre-existing renal, hepatic and cardiac diseases; anticipated difficult intubation; dementia and stroke with residual neurologic deficits 402 202 200 BIS target 40-60, sevoflurane titration, nitrous oxide (65%) and audible alarms set at 40/60 MAC-guided (0.7-1.3 age-adjusted MAC); sevoflurane titration; BIS recorded but blinded Sevoflurane & Nitrous oxide BIS/Bispectral Index (Aspect Medical Systems) NR NR NR 38.5 29.5-47.5 NR NR 40 29.5-50.5 74.8 73 I-II I-II N/A No NR NR 1.45 1.04-1.85 NR NR 1.29 0.83-1.76
13 chen2022 Taiwan single Inclusion: Adult patients undergoing video-assisted thoracoscopic surgery for lung resection; Exclusion: age <20 years; cerebral vascular disease or trauma; use of sedative or antipsychotic drugs within preoperative 30 days; stage 5 chronic kidney disease (estimated glomerular filtration rate <15 mL· min· 1.73 m− 2 ); New York Heart Association functional class 4; presence of circulatory shock needing vasoactive agents before surgery; emergency surgery; planned postoperative admission to intensive care unit for mechanical ventilation; pregnancy; patient refusal 76 39 37 M-Entropy target 40-60, sevoflurane titration Clinical monitoring (vital signs and clinical judgment); sevoflurane titration; M-Entropy recorded but blinded Sevoflurane M-Entropy (GE Healthcare) Shuang Ho Hospital; Taipei Medical University 59.8 15.7 NR NR 60.2 15.6 NR NR 53.8 48.6 I-II I-II N/A No NR NR 3.17 2.25-4.75 NR NR 3.5 2.42-4.12
14 chiu2007 Malaysia single Inclusion: New York Heart Association class I-III patients scheduled for elective cardiac surgery requiring hypothermic cardiopulmonary bypass; Exclusion: previous cardiac surgery; preoperative neurological disease; ejection fraction of less than 30%; known allergy to one of the drugs used; severe renal and hepatic impairment 20 10 10 BIS target 40-50, propofol TCI titration Clinical monitoring (target concentration 1.5-2.5 µg/ml); propofol titration based on perfusion pressure, BIS recorded but blinded (Propofol or Sevoflurane) & Fentanyl & Morphine BIS/Zipprep (Aspect Medical Systems) NR 52 12 NR NR 51 16 NR NR 30 20 NR NR N/A Yes NR NR 2.3 2.0-3.0 NR NR 2.13 2.0-2.92
15 cotae2021 Romania single Inclusion: age > 18 years; emergency noncardiac surgery expected to last > 2 h; ASA II-IV; Exclusion: neurotrauma; chronic use of psychoactive substances or alcohol; impaired preoperative cognitive function; pre-existing psychopathological symptoms; expected surgery time less than 2 h; neurological deficits; intubated prior to surgical procedure; remained intubated at end of surgical procedure 74 38 36 Entropy target 40-60 and SPI target <= 50, sevoflurane titration Clinical monitoring (somatic response and hemodynamic events); sevoflurane titration (Propofol or Etomidate) & Sevoflurane Entropy Module (GE Healthcare) None NR NR 45 27.5-59.5 NR NR 44 32.00-64.00 44.7 41.7 II-IV II-IV N/A No 2.21 NR NR NR 2.5 NR NR NR
16 crescioli2025 Denmark single Inclusion: 18 years of age or older; ASA physical status of 1 or 2; scheduled laparoscopic gynecological surgery; legally competent; Exclusion: renal or hepatic disease; laparoscopic surgery for cancer; relevant allergies towards anesthetics 154 80 74 BIS target 40-60, propofol/remifentanil titration Clinical monitoring (hemodynamics, tearing, sweating); propofol/remifentanil titration; BIS recorded but blinded Propofol & Remifentanil BIS VISTA 3.26 SW (Medtronic) Speciallæge Heinrich Kopps Legat NR NR 44 30-51 NR NR 39 30-49 100 100 I-II I-II N/A No NR NR 1.33 1.00-1.83 NR NR 1.42 1.08-1.83
17 das2024 India single Inclusion: Age >18 years to <60 years; Consenting patients posted for elective laparoscopic surgeries; ASA physical status class 2; Hypertensive patients with SBP <140 mmHg and DBP <90 mmHg; Exclusion: Inability of the patient to provide consent for study participation; Patients with difficulty in communication; ASA physical status class 1, class 3, or higher; Emergency surgeries; Pregnant patients; Age <18 years and >60 years; Patients with a history of uncontrolled hypertension, hypotension, or allergy to study drugs 60 30 30 BIS target 40-60, propofol titration Clinical monitoring (loss of eyelash reflex); propofol titration Sevoflurane & Nitrous Oxide NR None 51.46 6.82 NR NR 52.46 6.21 NR NR 56.67 50 II II N/A NR NR NR NR NR NR NR NR NR
18 drover2002 USA; Canada multi Inclusion: males and females between the ages of 18 and 80 yr; American Society of Anesthesiologists physical status I-III; undergoing elective surgical procedures scheduled for at least 30 min; able to read the consent form; Exclusion: scalp or skull abnormalities; history of head injury with loss of consciousness; psychiatric or supraspinal neurologic disorders; insulin-dependent diabetes mellitus; renal or hepatic disease; uncontrolled hypertension (systolic blood pressure > 160 mmHg, or diastolic pressure > 105 mmHg); body weight greater than 150% of ideal weight for height; scheduled to undergo cardiac, vascular, or cranial neurosurgical procedures 259 112 112 PSA 4000 (PSI) target 25-50 (maintenance) and 50-60 (emergence), propofol titration, alfentanil for analgesia/hemodynamics Clinical monitoring (hemodynamic/somatic signs); propofol titration, PSI recorded but blinded Propofol & Alfentanil & Nitrous Oxide PSA 4000 (Physiometrix, Inc.) Physiometrix, Inc. 42.9 NR NR NR 45.9 NR NR NR 67 65.2 I-II I-III PSI group counts: I(50)/II(62)/III(0). Standard Practice Control group counts: I(49)/II(60)/III(3). No 1.7 0.81 NR NR 1.7 0.79 NR NR
19 drover2011 USA single Inclusion: 65 years or greater; taking a beta-blocker for a minimum of 24 h preoperatively; ASA physical status I–III; non-cardiac surgery scheduled to last longer than 1 h; Exclusion: previous head injury; neurologic or psychiatric disorder; current use of psychoactive or anti-convulsive medications 67 32 35 SEDLine (PSI) target 25-50, sevoflurane titration, skin closure PSI target 50-60 Clinical monitoring (HR/BP ±20% baseline); sevoflurane titration; SEDLine PSI recorded but blinded Sevoflurane & Nitrous Oxide & Fentanyl SEDLine/PSI (Masimo) Hospira Inc. 75 5.7 NR NR 74.5 6.7 NR NR 37.5 31.4 II-III II-III Table reports counts for ASA II and III only, though inclusion criteria allowed I-III. NR NR NR NR NR NR NR NR NR
20 dundar2017 Turkey single Inclusion: ASA I-II; female patients; aged between 18 and 65 years; elective breast surgery; Exclusion: cardiac arrhythmia; central or autonomous nervous system disorders; on opioid treatment; infections at the site of planned blockade; known local anesthetic allergy 44 22 22 BIS target 40–60, sevoflurane and 0.02–0.5 µg/kg/min remifentanil titration, remifentanil adjusted to maintain ANI values 50–70 Hemodynamic parameters (HR/BP ±20% baseline) and BIS monitoring; sevoflurane and remifentanil titration Sevoflurane BIS / Bispectral Index (Aspect Medical Systems) NR 49.09 11.59 NR NR 46.55 8.18 NR NR 100 100 I-II I-II N/A No 1.5 0.41 NR NR 1.6 0.34 NR NR
21 elhor2013 Belgium single Inclusion: ASA II–III, older than 18 yr, elective laparoscopic rectosigmoidectomy (surgery >2h); Exclusion: impaired liver (plasma transaminases >2 times normal) or renal (creatinine >2mg/dl) function, history of drug abuse 50 25 25 M-Entropy (SE value) target 40-60, sevoflurane titration Clinical monitoring (HR/BP ±20% baseline); sevoflurane titration, SE recorded but blinded Sevoflurane & Propofol & Sufentanil M-Entropy/Datex-Ohmeda Support was provided solely from institutional and/or departmental sources. 61 15 NR NR 64 16 NR NR 32 32 II-III II-III N/A Yes NR NR 2.68 2.23-3.22 NR NR 2.25 1.82-2.62
22 ellerkmann2010A Germany single Inclusion: Men or women, aged 18 to 80 years, American Society of Anesthesiologists (ASA) physical status I, II or III who were to undergo minor surgery expected to last at least one hour, orthopaedic patients receiving regional anaesthesia for intra- and postoperative pain control for surgery to the upper or lower extremity in combination with general anaesthesia; Exclusion: history of any disabling central nervous or cerebrovascular diseases, hyper- sensitivity to opioids or substance abuse, or a treatment with opioids or any psychoactive medication, insufficient regional anaesthesia 79 27 27 BIS target 50, propofol/remifentanil titration Clinical monitoring (blood pressure, heart rate, sweating, tear production, movement); propofol titration, BIS/Entropy recorded but blinded Propofol & Remifentanil BIS/Bispectral Index (Aspect Medical Systems) NR 50.6 15.7 NR NR 53.6 18.4 NR NR 67 55.6 I-III I-III N/A No 1.67 0.51 NR NR 1.99 0.84 NR NR
23 ellerkmann2010B Germany single Inclusion: Men or women, aged 18 to 80 years, American Society of Anesthesiologists (ASA) physical status I, II or III who were to undergo minor surgery expected to last at least one hour, orthopaedic patients receiving regional anaesthesia for intra- and postoperative pain control for surgery to the upper or lower extremity in combination with general anaesthesia; Exclusion: history of any disabling central nervous or cerebrovascular diseases, hyper- sensitivity to opioids or substance abuse, or a treatment with opioids or any psychoactive medication, insufficient regional anaesthesia 79 25 27 Entropy (SE) target 50, propofol/remifentanil titration Clinical monitoring (blood pressure, heart rate, sweating, tear production, movement); propofol titration, BIS/Entropy recorded but blinded Propofol & Remifentanil Entropy Module (GE Healthcare) NR 58.1 14.2 NR NR 53.6 18.4 NR NR 60 55.6 I-III I-III N/A No 2.06 0.74 NR NR 1.99 0.84 NR NR
24 fakhr2014 Iran single Inclusion: aged over 60 years; ASA class I-III; candidates for elective abdominal surgery; Exclusion: psychotic disorders; dementia; previous cerebrovascular accident; head trauma; drug abuse 68 34 34 BIS target 45-65, isoflurane titration, fentanyl 50 ug administered for hypertension or tachycardia Clinical monitoring (HR/BP ±20% baseline); isoflurane titration Isoflurane & Nitrous Oxide Danmeter – CSM I Research council of Hamedan University of Medical Sciences NR NR NR NR NR NR NR NR NR NR I-III I-III N/A NR NR NR NR NR NR NR NR NR
25 freo2010 Italy single Inclusion: undergoing LAGB for morbid obesity (BMI >40 kg m−2); Exclusion: age less than 18 years; ASA score >III; history of difficult tracheal intubation; disabling central nervous system or cerebrovascular disease; chronic obstructive lung disease; coronary artery disease and/or myocardial infarction; congestive heart failure; history of allergy to anesthetic drugs; hypersensitivity to opioid or substance abuse; treatment with opioid or any psychoactive medication; myasthenia gravis; malignant hyperthermia 60 30 30 AAI target 20 ± 5, sevoflurane titration Clinical monitoring (HR/BP ±20% baseline); sevoflurane titration Sevoflurane AAI/Alaris medical system (Hampshire, UK) departmental funds 41 11 NR NR 38 11 NR NR 70 73.3 NR NR Exclusion criteria specify ASA > III, implying participants were I-III, but specific range per group not reported. No 1.48 0.33 NR NR 1.53 0.4 NR NR
26 fritz2021 USA single Inclusion: Patients aged 60 yr or older scheduled for surgery with general anaesthesia and anticipated hospital stay of at least 2 days; Exclusion: Patients unable to complete interviews in English; delirium at baseline; history of intraoperative awareness; scheduled for a second surgery within 5 days of the initial surgery 1192 591 601 BIS target >=40, volatile anaesthetic titration, primarily to minimise EEG suppression Clinical monitoring; usual care, BIS recorded but clinicians blinded Volatile anaesthetic BIS Quatro (Medtronic Corp.) US National Institute on Aging; US National Institute for General Medical Sciences NR NR 69 65-74 NR NR 69 65-76 45 45 I-IV I-IV N/A No NR NR 5.28 3.95-6.65 NR NR 5.2 3.9-6.63
27 gruenewald2007 Germany single Inclusion: ASA physical status 1–2; undergoing elective gynaecological laparoscopy; lasting at least 1 h; Exclusion: pregnant; neuromuscular or neurological disease; use of CNS-active medication; abuse of alcohol or illicit drugs 72 37 35 M-Entropy target state entropy 40-60, propofol/remifentanil titration, remifentanil adjusted to keep response-state entropy difference < 10 Clinical monitoring (standard clinical signs); propofol/remifentanil titration; pEEG (Entropy and BIS) recorded but blinded Propofol & Remifentanil M-Entropy (GE Healthcare) GE Healthcare 38 9 NR NR 33 9 NR NR 100 100 I-II I-II N/A No 1.83 0.65 NR NR 1.85 0.77 NR NR
28 gruenewald2021 Germany; Finland; Netherlands; Hungary multi Inclusion: Men and women between 18 and 80 years of age; able to provide written informed consent; undergoing elective surgery demanding general anaesthesia with tracheal intubation; expected procedure duration of at least 2 h; Exclusion: atrial fibrillation; more than five ventricular extrasystoles per minute at baseline or cardiac pacemaker in place; need for invasive BP monitoring; patients with haemodynamics considered 'inadequate' at baseline; planned epidural anaesthesia/analgesia; surgery in the prone position; surgery with an expected high risk of significant blood loss (>500 ml); surgery requiring continuous infusion of a neuromuscular blocking agent; BMI more than 35 kg m-2; patients with chronic opioid abuse 494 246 248 Entropy target 40-60, Surgical Pleth Index (SPI) target 20-50, propofol/remifentanil titration Clinical monitoring (autonomic signs); propofol/remifentanil titration; pEEG and SPI recorded but blinded Propofol & Remifentanil Entropy (GE Healthcare) GE Healthcare 48 15 NR NR 48 16 NR NR 76.9 80.2 NR NR N/A No 2.33 1.02 NR NR 2.37 0.98 NR NR
29 guo2012 China single Inclusion: Severe burns patients undergoing eschar excision (<1week); age 18-65 years; ASA II-III; TBSA 31%-50% or three-degree burns 11%-20%; Exclusion: Drug allergy; significant preoperative cardiopulmonary, hepatic, or renal dysfunction; severe obesity (BMI > 30 kg/m²) 80 40 40 BIS target 40-60, propofol/remifentanil TCI titration Clinical monitoring (HR/BP ±20% baseline, body movement); propofol/remifentanil TCI titration Propofol & Remifentanil BIS/A-2000 (Aspect Medical Systems) NR NR NR NR NR NR NR NR NR NR NR II-III II-III N/A No NR NR NR NR NR NR NR NR
30 guo2015 China single Inclusion: severe burns, elective escharectomy (<1 week), ASA class II-III, total burn surface areas 31-50% or third-degree burn injuries 11-20%, age 18-65 years, weight 40-90 kg; Exclusion: drug allergies, apparent heart, lung, liver or kidney dysfunction, seriously overweight (BMI > 30 kg/m2) 80 40 40 BIS target 40-60, propofol/remifentanil TCI titration Clinical monitoring (blood pressure, heart rate, and body movement); propofol/remifentanil TCI titration Propofol & Remifentanil BIS/Bispectral Index (Aspect Medical Systems) NR 42.5 13.33 NR NR 39.95 14.7 NR NR 35 30 II-III II-III N/A Yes 2.97 0.61 NR NR 3.05 0.57 NR NR
31 hasnain2023 India single Inclusion: ASA I and II, aged 18–65 years, undergoing surgery under general anesthesia; Exclusion: significant cardiovascular, respiratory, hepatic and renal disease, psychiatric illness, surgeries where major blood loss or fluid shift expected, long-term drug or alcohol abuse 61 30 31 BIS target 40-60, isoflurane titration MAC-guided; isoflurane titration (MAC 0.7-1.3) Isoflurane & (O2 or N2O) BIS / Bispectral Index (Medtronic) None NR NR 45 29-50 NR NR 41 29-52 36.7 38.7 I-II I-II ASA classes III and IV were excluded. No 2.82 0.52 NR NR 2.9 0.58 NR NR
32 he2023 China single Inclusion: Male or female patients over 60 years old scheduled for elective major abdominal surgery; Exclusion: patient refusal, a history of dementia or psychiatric illness, difficulty with follow-up, or poor compliance 125 61 64 rEEG waveform target C-D sedation, propofol titration Clinical monitoring; experience-guided titration; rEEG recorded but blinded Propofol & Remifentanil SedLine/PSI (Masimo) China primary health care foundation NR NR 68 65-73 NR NR 69 65-74 36 33 II-IV II-III N/A No NR NR 2.58 2.01-3.55 NR NR 2.67 2.14-3.18
33 huang2024 China single Inclusion: age ranging from 20 to 80 years; estimated operation time of two to three hours; body mass index ≤30 kg/m2; normal preoperative heart, liver, lung, and renal function; Exclusion: cerebrovascular disease, cognitive impairment, or prolonged use of antipsychotic drugs; inability to cooperate or speak; audiovisual dysfunction; alcohol and drug dependence; severe allergy or be prohibited from general anesthesia by endotracheal intubation, be transferred to ICU after surgery; refusal to participate in the study 120 60 60 BIS target 40-60, sevoflurane/remifentanil/propofol titration Clinical monitoring; titration based on clinical signs; BIS not monitored Sevoflurane & Remifentanil & Propofol BIS EEG VISTA/Bispectral Index (Covidien, Mansfield, MA, USA) None 51.65 17.13 NR NR 51.46 17.2 NR NR 55 53.3 I-III I-III N/A No 2.84 0.46 NR NR 2.97 0.36 NR NR
34 jayawardhini2021 India NR Inclusion: Age 30-50 years; Scheduled for laparoscopic cholecystectomy; Suitable for general anesthesia 100 50 50 BIS target 40-45, propofol titration Standard Practice (established protocols); BIS recorded but blinded Isoflurane & Propofol NR NR 35.9 NR NR NR 33.6 NR NR NR NR NR NR NR N/A Yes 0.968 NR NR NR 1.038 NR NR NR
35 jiahai2012 China single Inclusion: undergoing first-time OPCAB surgery; good or only slightly reduced left ventricular function (ejection fraction 40%, left ventricular end-diastolic pressure -15 mmHg); below 70 years of age; Exclusion: requiring CPB either electively or during the course of surgery; renal insufficiency (creatinine 1.5 mg/dL); hepatic impairment (alanine aminotransferase or aspartate aminotransferase 40 U/mL); misused alcohol or drugs 70 35 35 S/5 Entropy Module target SE 45-55 and RE-SE difference < 10, propofol/sufentanil titration Clinical monitoring (HR/BP ±25% baseline); propofol/sufentanil titration; Entropy recorded but blinded Propofol & Sufentanil S/5 Entropy Module (Datex-Ohmeda) Science and Technology Programme Fundition of Yantai, Yantai, China 59 7 NR NR 60 6 NR NR 24 20 NR NR N/A No 4.27 0.7 NR NR 4.4 0.57 NR NR
36 jildenstal2011 Sweden single Inclusion: ASA 1-4, aged 18-92 years, scheduled to undergo anterior or posterior segment ophthalmic surgery; Exclusion: pregnancy, inability to fulfil investigational procedures due to mental disabilities, hearing impairment, substance abuse, operated on out-of-hours, inability to fulfil perioperative protocol. 450 224 226 A-line monitor AAI target 15-25, desflurane/propofol titration Clinical monitoring (titration based on hemodynamic and autonomic signs); desflurane/propofol titration; AAI recorded but blinded Propofol & Desflurane & Nitrous oxide A-line monitor (Danmeter A/S) Danmeter-Denmark; Örebro county council NR NR 60 NR NR NR 60.5 NR 42.9 38.9 I-IV I-IV I-II pooled NR NR NR NR NR NR NR NR NR
37 kabukcu2016 Turkey single Inclusion: patients that will have open heart surgery; Exclusion: needed emergency surgery; unstable angina pectoris history; hemodynamic instability; organ transplants; acute myocardial infarction; acute heart failure; preoperative medical and mechanical inotropic support; pulmonary embolism; renal failure; hepatic cirrhosis history 70 35 35 BIS target 35-45, propofol/remifentanil titration Clinical monitoring (haemodynamics/pupils); propofol/remifentanil titration; BIS recorded but blinded Propofol & Remifentanil BIS/Bispectral Index (Aspect Medical Systems) None 58.7 11.4 NR NR 56.2 10.4 NR NR NR NR NR NR N/A No 4.46 0.91 NR NR 4.82 0.69 NR NR
38 kamali2017 Iran single Inclusion: non-emergency patients aging 40 to 75 years old candidated for CABG; class II or III ASA; no past records of ICU hospitalization and long-term intubation; operation duration 4 to 6 hours; Exclusion: emergency candidates; operation <4 or >6 hours; age <40 or >75; prescribed anesthetic gases 120 60 60 BIS target 40-50, Propofol/Atra/Amprazolam/Sufentanil titration Clinical monitoring (HR/BP ±15% baseline); TIVA titration Propofol & Sufentanil & Atracurium BIS/Bispectral Index (Aspect Medical Systems) NR 66.8 NR NR NR 67.6 NR NR NR 38.8 39.2 II-III II-III arms pooled No NR NR NR NR NR NR NR NR
39 karaca2014 Turkey single Inclusion: aged 20 to 60 years; operated for supratentorial mass; ASA I or II; Exclusion: cardiac failure; renal failure; anaemia; ischemic heart disease; liver disease; gastrointestinal system disease; diabetes mellitus; hypothalamus- pituitary gland disorders; diuretic use; hypoalbuminemia; hyperglycaemia; electrolyte imbalance; alcohol consumption; hormone replacement therapy; pregnancy; lactation; psychiatric condition interfering with consent 82 41 41 BIS target 40-60, propofol/remifentanil titration Clinical monitoring (HR/BP ±20% baseline); propofol/remifentanil titration; BIS recorded but blinded Propofol & Remifentanil BIS Quatro/Bispectral Index (Aspect Medical Systems) None 48.83 14.729 NR NR 48.17 15.778 NR NR 41.46 56.1 I-II I-II N/A Yes 4.52 1.5 NR NR 4.37 1.71 NR NR
40 karwacki2014 Poland single Inclusion: ASA I patients undergoing elective surgery due to lumbar discopathy (lumbar microdiscectomy due to a herniated nucleus pulposus); Exclusion: NR 60 30 30 BIS monitoring target 40-50, TCI propofol/fractionated fentanyl titration Clinical monitoring (HR/MAP); propofol and opioid titration Propofol & Fentanyl BIS/Bispectral Index (Aspect Medical Systems) NR 39.5 9.5 NR NR 39.5 9.5 NR NR 43.3 43.3 I-I I-I N/A No 1.3 0.3 NR NR 1.5 0.37 NR NR
41 kerssens2009 USA single Inclusion: Patients 18 yr of age or older scheduled for hip or knee replacement surgery, primary or revision, under general anesthesia; Exclusion: history or status that could compromise or skew electroencephalogram recordings (illicit drug abuse, antipsychotic medication treatment, head trauma resulting in the loss of consciousness, central nervous system disorders e.g., epilepsy), MMSE score below 24, severe visual or auditory handicaps, illiterate, nonfluent English speakers 109 62 47 BIS target 50-60, sevoflurane titration Clinical signs (HR/BP); sevoflurane titration; BIS recorded but blinded Sevoflurane BIS/Bispectral Index (Aspect Medical Systems) None (authors affiliated with Aspect Medical) 61.2 11.4 NR NR 63.9 11.8 NR NR 55 66 I-III I-III N/A No 2.1 0.85 NR NR 1.87 0.8 NR NR
42 kreuer2003A Germany Single Inclusion: Men or women, aged 18-80 yr, ASA I-III, scheduled to undergo minor orthopedic surgery expected to last at least 1 h; Exclusion: history of any disabling central nervous or cerebrovascular diseases, hypersensitivity to opioids or substance abuse, or treatment with opioids or any psychoactive medication. 120 40 40 BIS monitoring propofol infusion was adjusted to target 50; 15 min before the end of surgery, 60 Clinical monitoring (HR/BP, movement, eye opening, swallowing, etc); propofol titration Propofol & Remifentanil BIS/Bispectral Index (Aspect Medical Systems) Departmental sources. 43.8 4.2 NR NR 46.1 14.5 NR NR 50 50 I-III I-III N/A No 2.02 0.68 NR NR 1.8 0.74 NR NR
43 kreuer2003B Germany Single Inclusion: Men or women, aged 18-80 yr, ASA I-III, scheduled to undergo minor orthopedic surgery expected to last at least 1 h; Exclusion: history of any disabling central nervous or cerebrovascular diseases, hypersensitivity to opioids or substance abuse, or treatment with opioids or any psychoactive medication. 120 40 40 Narcotrend target D0 (maintenance) or C1 (15 min before end), propofol/remifentanil titration Clinical monitoring (HR/BP, movement, eye opening, swallowing, etc); propofol titration Propofol & Remifentanil Narcotrend (MonitorTechnik) Departmental sources. 44.8 15.9 NR NR 46.1 14.5 NR NR 50 50 I-III I-III N/A No 2.12 1.13 NR NR 1.8 0.74 NR NR
44 kreuer2005A Germany single Inclusion: Men or women, aged 18 – 80 yr, ASA physical status I, II, or III, scheduled for minor orthopedic surgery expected to last at least 1 h; Exclusion: history of any disabling central nervous or cerebrovascular disease, hypersensitivity to opioids or substance abuse, treatment with opioids or any psychoactive medication 120 40 40 BIS target 50 (maintenance) / 60 (15 min before end), desflurane titration Clinical monitoring (HR, arterial blood pressure, movements); desflurane titration Desflurane & Remifentanil BIS/Bispectral Index (Aspect Medical Systems) Departmental sources. 46.5 14.1 NR NR 43.6 16 NR NR 50 50 I-III I-III N/A No 1.883 0.95 NR NR 2.08 0.85 NR NR
45 kreuer2005B Germany single Inclusion: Men or women, aged 18 – 80 yr, ASA physical status I, II, or III, scheduled for minor orthopedic surgery expected to last at least 1 h; Exclusion: history of any disabling central nervous or cerebrovascular disease, hypersensitivity to opioids or substance abuse, treatment with opioids or any psychoactive medication 120 40 40 Narcotrend target D0 (maintenance) / C1 (15 min before end) Clinical monitoring (HR, arterial blood pressure, movements); desflurane titration Desflurane & Remifentanil Narcotrend (MonitorTechnik) 44.7 15.6 NR NR 43.6 16 NR NR 50 50 I-III I-III N/A No 2.033 0.833 NR NR 2.08 0.85 NR NR
46 kunst2020 UK single Inclusion: Patients older than 64 years undergoing elective coronary artery bypass graft (CABG) surgery on cardiopulmonary bypass with a baseline Mini Mental State Examination (MMSE) above 24; Exclusion: diseases of the central nervous system; dementia (MMSE <= 24); inadequate knowledge of English; current or past psychiatric illness; current use of tranquilizers or antidepressants; severe visual, auditory, or motor handicaps 82 42 40 BIS target 50 ± 10, propofol/isoflurane/remifentanil titration, rScO2-guided (target > baseline -15% and > 50%) Clinical monitoring (HR/BP baseline); isoflurane/remifentanil titration, BIS and rScO2 recorded but blinded (Propofol or Isoflurane) & Remifentanil BIS (Medtronic) Department of Research and Development, King’s College Hospital Foundation Trust 71.6 5 NR NR 72 4.3 NR NR 21 15 NR NR N/A Yes 5.12 1.27 NR NR 4.87 1.65 NR NR
47 lai2010 China single Inclusion: Patients with liver cancer scheduled to undergo microwave coagulation under the guidance of computed tomography (CT); ASA grades II to III; Exclusion: neurologic or psychiatric problems; hearing defects; alcohol or drug dependence 40 20 20 Narcotrend target D2-E0, propofol titration Clinical monitoring (HR 50–100 bpm, BP ±20% baseline, body movement); propofol titration Propofol & Fentanyl Narcotrend (MonitorTechnik) NR 44 NR NR NR 41 NR NR NR NR NR II-III II-III N/A No 1.52 0.5 NR NR 1.47 0.52 NR NR
48 lenkin2014 Russia single Inclusion: age >18 years; scheduled repair and/or replacement of 2 or more cardiac valves requiring CPB; Exclusion: stenosis of coronary arteries requiring simultaneous coronary artery bypass grafting; extreme obesity (body mass index >40 kg m–2); chronic alcohol or drug abuse; participation in another study 50 25 25 Cerebral State Index (CSI) target 40-60, propofol/midazolam titration Clinical monitoring (consciousness, sweating, lacrimation, HR/BP); propofol titration Midazolam & Propofol & Fentanyl Cerebral State Monitor / CSM 2 (Danmeter) None 52 10 NR NR 54 10 NR NR 44 64 NR NR N/A Yes NR NR 3.42 3.05-4.13 NR NR 3.67 3.22-3.97
49 leslie2010 Australia; New Zealand; China; Hong Kong multi Inclusion: surgical patients aged 18 yr or older, at high risk of awareness (cesarean delivery, high-risk cardiac surgery, acute trauma with hypovolemia, rigid bronchoscopy, significant impairment of cardiovascular status, severe end-stage lung disease, history of awareness, anticipated difficult intubation); Exclusion: known or suspected heavy alcohol intake, chronic benzodiazepine or opioid use, current protease inhibitor therapy 2463 1225 1238 BIS target 40-60, anesthetic titration Routine care; clinician discretion Propofol or Volatile agent (nitrous oxide) BIS/Bispectral Index (Aspect Medical Systems) Australian and New Zealand College of Anaesthetists; Chinese University of Hong Kong NR NR 61 46-71 NR NR NR NR 38 NR I-V I-V ASA >= 3 reported as 74% for total cohort, not split by arm or range. No NR NR 3.1 1.4-4.4 NR NR NR NR
50 lin2011 Taiwan single Inclusion: ASA II to III, aged 43 to 92 years, elective PV with MAC; Exclusion: NR 220 110 110 AAI target 25-50, propofol titration OAA/S-guided; propofol titration Propofol & Fentanyl & Midazolam A-Line/AAI (Danmeter) Tri-Service General Hospital NR NR 76 44-90 NR NR 77 43-92 71.8 62.7 II-III II-III N/A No 0.88 0.23 NR NR 0.86 0.23 NR NR
51 luginbuhl2003A Switzerland single Inclusion: Patients scheduled for gynecological surgery expected to last longer than 15 min and requiring general anesthesia; Exclusion: ASA physical status higher than 3; central nervous system disease (i.e. history of cerebrovascular disease or epilepsy); taking EEG-affecting drugs 160 40 40 BIS target 45-55, desflurane or propofol titration, last 15 min target allowed up to 65. Clinical monitoring (hemodynamic and vital signs); desflurane titration; BIS recorded but blinded Desflurane A-2000/BIS (Aspect Medical Systems, Inc.) Research Fund of the Department of Anesthesiology, University Hospital of Bern, Switzerland 45.2 17.5 NR NR 47.1 17.8 NR NR 100 100 I-III I-III ASA III patients were eligible but none were included in the final characteristics table Yes 1.68 0.97 NR NR 1.52 0.89 NR NR
52 luginbuhl2003B Switzerland single Inclusion: Patients scheduled for gynecological surgery expected to last longer than 15 min and requiring general anesthesia; Exclusion: ASA physical status higher than 3; central nervous system disease (i.e. history of cerebrovascular disease or epilepsy); taking EEG-affecting drugs 160 40 40 BIS target 45-55, desflurane or propofol titration, last 15 min target allowed up to 65. Clinical monitoring (hemodynamic and vital signs); propofol titration; BIS recorded but blinded Propofol A-2000/BIS (Aspect Medical Systems, Inc.) Research Fund of the Department of Anesthesiology, University Hospital of Bern, Switzerland 46.3 15.4 NR NR 48.7 15.7 NR NR 100 100 I-III I-III ASA III patients were eligible but none were included in the final characteristics table Yes 1.52 1.11 NR NR 1.51 1.17 NR NR
53 ma2024 China single Inclusion: selection of laparoscopic gastrointestinal tumor resection; Age 18–70 years; American Society of Anesthesiologists class I-III; patients cooperating in completing the mini-mental state examination (MMSE) scale assessment; Exclusion: Intolerance to GA or allergy to anesthetic drugs; Presence of preoperative disorders of consciousness or mental illness; Presence of ulcers and wounds on the head and face that prevent proper placement of equipment such as monitoring electrode pads; Patients with severe liver and kidney insufficiency or serious diseases of a vital organ such as heart and lungs; patients transferred to the ICU postoperatively 108 54 54 Narcotrend index (NTI) target D2-E1, isoproterenol titration, the duration of NTI<35 was considered deep anesthesia Clinical monitoring; hemodynamic targets and anesthesiologist experience Midazolam & Sufentanil Narcotrend (Chindex Medical Limited, China) Medical Science Research Project of Hebei Province 68.83 4.27 NR NR 69.22 4.85 NR NR 51.85 37.04 I-III I-III N/A Yes 3.1 0.41 NR NR 3.05 0.46 NR NR
54 maattanen2002 Sweden single Inclusion: ASA I–II, elective open spine surgery 30 15 15 AAI-index target 20±5, desflurane titration Clinical monitoring (HR/BP ±15% baseline, sweating, tearing); desflurane titration Desflurane & Nitrous oxide A-Line ARX index AEP Monitor (Danmeter A/S) NR 44 13 NR NR 49 10 NR NR NR NR I-II I-II N/A No 1.63 0.57 NR NR 1.68 0.5 NR NR
55 sudhakaran2018 India single Inclusion: undergoing lumbar spine surgeries, ASA I-II, aged 20-60 years; Exclusion: psychiatric illness, clinically significant cardiovascular, respiratory, hepatic and renal disease, long-term drug or alcohol abuse 63 21 21 BIS target 45–55, desflurane titration Clinical monitoring (HR/BP ±20% baseline); desflurane titration Desflurane & Nitrous Oxide BIS sensor Xp (Aspect Systems) None 42.05 12.81 NR NR 40.38 13.12 NR NR 38.1 23.8 I-II I-II N/A No 1.9 0.57 NR NR 1.84 0.51 NR NR
56 mozafari2014 Iran single Inclusion: adult patients of American Society of Anesthesiologists (ASA) physical status I-III, aged 18 to 65 years scheduled for elective abdominal surgery under general anesthesia; Exclusion: cardiopulmonary disorders, history of head trauma, cerebrovascular accident, psychotic disorders, dementia, depression, history of drug or substances abuse, or lack of sufficient fluency in Persian language 333 163 170 BIS target range 45-65, isoflurane or halothane with N2O titration, sufentanil/thiopental/atracurium induction; anesthesia maintained by hemodynamic variables and BIS values Clinical monitoring (hemodynamic variables); isoflurane or halothane with N2O titration, BIS recorded but clinicians blinded (Isoflurane or Halothane) & N2O BIS Sensor (danmeter-CSMI) Research Council of Hamadan University of Medical Sciences 47.389 18.869 NR NR 48.172 19.212 NR NR 61.3 65.9 I-III I-III N/A No NR NR NR NR NR NR NR NR
57 myles2004 Australia; China; New Zealand; Thailand; UK multi Inclusion: Aged 18 years or older; undergoing relaxant general anaesthesia; at least one risk factor for awareness (e.g., caesarean section, high-risk cardiac surgery, acute trauma with hypovolaemia, rigid bronchoscopy, significant impairment of cardiovascular status, severe end-stage lung disease, past history of awareness, anticipated difficult intubation, heavy alcohol intake, chronic benzodiazepine or opioid use, or protease inhibitor therapy). Exclusion: Inadequate comprehension of English language; traumatic brain injury; memory impairment; psychosis; known or suspected electroencephalograph abnormality (e.g., epilepsy, previous brain resection, or scarring); not expected to be available for interview postoperatively. 2463 1225 1238 BIS target 40-60, hypnotic drug titration; titration to BIS 55-70 allowed during wound closure Clinical monitoring; anaesthetic drug titration according to clinical judgment; BIS recorded but blinded Propofol or Thiopentone or Nitrous oxide or Sevoflurane or Isoflurane or Enflurane or Halothane A-2000 BIS/Bispectral Index (Aspect Medical Systems) Australian and New Zealand College of Anaesthetists; Alfred Hospital Research Trust; Royal Hobart Hospital Research Foundation; Centre for Encouragement of Philanthropy in Australia 58.1 16.5 NR NR 57.5 16.9 NR NR 39 37 I-V I-V N/A No NR NR 3.2 1.5-4.4 NR NR 3.1 1.3-4.5
58 nitzschke2014 Germany single Inclusion: age 18 years or older; undergoing elective on-pump cardiac surgery; ASA physical status of 3 to 4; Exclusion: contraindication to the administration of volatile anaesthetics; active infection with a temperature more than 38°C; any history of neurological disease 60 31 29 BIS target 40-60, sevoflurane titration, minimum oxygenator fresh gas concentration 0.3% Fixed-dose sevoflurane; 1.8% inspired concentration maintenance Sevoflurane BIS VISTA (Covidien) institutional resources from the Department of Anaesthesiology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany 67 9.8 NR NR 65.7 9.2 NR NR 35 41 III-IV III-IV N/A Yes 4.105 1.21 NR NR 3.92 1.02 NR NR
59 ozkavak2025 Turkey single Inclusion: adult patients who were scheduled for elective arthroscopic meniscopathy surgery; Exclusion: patients less than 18 years old; ≥3 ASA status; central neurological disease; drug (anticonvulsant) sensitivity; chronic drug (opioid, benzodiazepine, etc.) and alcohol use; MAP above 60 mmHg and HR below 50 beats/minute; operation duration < 20 minutes or > 60 minutes 40 20 20 BIS target 40-60, desflurane titration, fentanyl boluses administered before incision and as needed Clinical monitoring (HR/BP ±20% baseline, movement, sweating, etc.); desflurane titration Propofol & Desflurane & Nitrous oxide & Fentanyl BIS/Bispectral Index (Aspect Medical Systems) None NR NR NR NR NR NR NR NR NR NR NR NR ASA status < 3 (I-II assumed based on exclusion criteria, but specific breakdown not reported) NR NR NR NR NR NR NR NR NR
60 payas2013 Turkey single Inclusion: ASA II-III; age 30-65 years; cardiac problem but no previous history of cardiac surgery; scheduled for elective open cholecystectomy under general anesthesia with desflurane. Exclusion: decompensated heart failure; history of myocardial infarction in the last 6 months; liver failure; chronic renal insufficiency; history of neurological and psychiatric diseases; respiratory system diseases; alcohol and drug use; history of allergy. 100 50 50 BIS target 50-60, desflurane titration Clinical monitoring (HR/MAP ±20% baseline); desflurane titration; BIS recorded but blinded Desflurane & N2O BIS XP monitor / Aspect A 2000TM (Aspect Medical Systems/Medtronic) None 52.68 8.7 NR NR 55.58 8.24 NR NR 62 60 II-III II-III N/A No 1.9 0.66 NR NR 1.8 0.71 NR NR
61 perez-otal2022 Spain single Inclusion: > 65 years, major surgical interventions duration >= 2 hours, post-operative hospital stay >= 2 days, ASA physical status I-IV, balanced general anaesthesia maintained with halogenated gases; Exclusion: unable to conduct interviews, communication difficulties (language, hearing, visual), CNS diseases (dementia, memory deterioration, MMSE score <= 23), rejection of inclusion, not submitted to general anaesthesia (neuraxial or regional) 200 98 102 BIS target 40-60, halogenated gases titration Clinical monitoring (MAC value and hemodynamic parameters); halogenated gases titration, BIS recorded but blinded (Desflurane or Sevoflurane) & Remifentanil & Fentanyl BIS Quatro/Bispectral Index (Medtronic) NR 74.99 6.77 NR NR 75.75 6.3 NR NR 46.46 53.53 I-IV I-IV N/A NR NR NR NR NR NR NR NR NR
62 persec2012 Croatia single Inclusion: aged 18 years or older; ASA physical status II or III; undergoing major abdominal surgery under general anaesthesia; Exclusion: memory impairment; psychosis; known or suspected electroencephalograph abnormality (e.g., epilepsy, previous brain operation); chronic use of psychoactive medication; operation time exceeding six hours 40 20 20 BIS target 50-60, sevoflurane titration Clinical monitoring (ECG, IBP, SpO2, etCO2); sevoflurane titration; BIS recorded but blinded Sevoflurane & Nitrous oxide & (Midazolam or Fentanyl) A-2000 BIS monitor (Aspect Medical Systems) None NR NR 64.5 NR NR NR 66.5 NR 45 50 II-III II-IV Median/range reported. Note: Table 56 reports max ASA 4 for control, despite text stating inclusion only II-III. Yes NR NR 3.25 NR NR NR 2.77 NR
63 priya2024 India single Inclusion: Aged between 18 and 60 years; Surgeries under general anaesthesia; Different types of elective surgery; ASA physical status I-II; Exclusion: Other fever causes (malaria, brucella, leptospira, enteric fever, drug-induced fever, viral fever, rickettsial fever); Prior history of respiratory, hepatic, renal, hematological, and neurological problems; heart failure; arrhythmias; Age < 16 years 60 30 30 BIS target 40-60, inhaled anaesthetics titration Clinical monitoring; anesthetic titration (Propofol or Sevoflurane) & Fentanyl & Midazolam BIS/Bispectral Index NR NR NR NR NR NR NR NR NR NR NR I-II I-II ASA I-II was an inclusion criterion for the entire study population. Yes 1.94 1.77 NR NR 1.23 1.43 NR NR
64 puri2003 India single Inclusion: 18-70 yr, coronary artery grafting (CABG) or valve replacement under cardiopulmonary bypass (CPB); Exclusion: known neurological disorders; poor ventricular function (ejection fraction <40%); New York Heart Association (NYHA) Grade IV; diabetes mellitus; impaired renal or hepatic function 30 14 16 BIS target 45-55, isoflurane titration, 65-75 target during the last 30 min Clinical signs (HR/BP, sweating, lacrimation); isoflurane titration; BIS recorded but blinded Isoflurane & N2O & Morphine & Midazolam & Thiopental & Vecuronium Aspect A-1000 (Aspect Medical Systems, Inc.) NR 38.25 14.02 NR NR 32.08 13.84 NR NR NR NR NR NR N/A Yes 4.92 0.75 NR NR 4.75 0.67 NR NR
65 quan2019 China single Inclusion: aged 60 years or older, scheduled for abdominal surgery, ASA I–II; Exclusion: preexisting neurological or clinically evident neurovascular diseases, MMSE <23, anticipated difficulty with neuropsychological assessment, associated medical problems that may lead to significant complications, blindness, deafness, Chinese not being first language, drug or alcohol abuse, prior surgery, severe perioperative complications 105 52 53 BIS target 30–45, propofol titration BIS target 45–60, propofol titration Propofol & Remifentanil BIS (not reported) Departmental funding only. 65.6 3.77 NR NR 63.9 4.56 NR NR 43.33 46.67 I-II I-II N/A No 3.07 0.8 NR NR 3.22 1.07 NR NR
66 renaud-roy2022 Canada single Inclusion: elective colonic surgery; > 18 years old; ASA Class I–III; epidural analgesia planned; Exclusion: allergies to protocol drugs; contraindication/refusal for epidural; chronic arrhythmic cardiac conditions or pacemaker; chronic pain with opioid use >3 times/week for 4 weeks; beta-blocker treatment 55 28 27 BIS target 45–55, desflurane titration, NOL index target < 20 for remifentanil titration Clinical monitoring (vital signs and MAC); desflurane and remifentanil titration, BIS and NOL recorded but blinded Desflurane & Remifentanil BIS/Bispectral Index (Medtronic) Canadian Anesthesia Research Foundation; Medasense Ltd; Department of Anesthesiology and Pain Medicine of Maisonneuve-Rosemont Hospital/CEMTL, University of Montreal 67.82 8.6 NR NR 66.4 11.6 NR NR 39.3 48.1 II-III II-III N/A Yes 3.1 1 NR NR 2.9 1 NR NR
67 riad2007 Saudi Arabia single Inclusion: elderly patients aged 60-75 yr, ASA physical status I–II, scheduled for elective ophthalmic surgery under general anaesthesia; Exclusion: history of cardiac, pulmonary, liver or renal disease or significant obesity (BMI >30), diagnosed Alzheimer disease, dementia, brain atrophy, previous cerebrovascular accident, other neurological disorders, long-term use of drugs affecting the central nervous system 72 36 36 M-Entropy SE target 50 (RE-SE difference <10), propofol titration Clinical monitoring (verbal command); propofol titration (initial induction 1.75 mg kg-1); entropy recorded but blinded Sevoflurane M-Entropy plug-in Module S/5 (Datex-Ohmeda) None 66.1 4.5 NR NR 66.6 3.9 NR NR 25 33.3 I-II I-II N/A NR NR NR NR NR NR NR NR NR
68 rinaldi2005 Italy single Inclusion: ASA I/II patients scheduled for elective major abdominal surgery; Exclusion: perceptible hearing loss, language difficulties, neurological dysfunction, treatment with drugs affecting the central nervous system, inability to speak or understand Italian 100 50 50 AAI target 20±5, sevoflurane titration Clinical monitoring (Evans scoring system: HR/BP ±20% baseline, sweating, tears); sevoflurane titration Sevoflurane A-line AEP monitor (Danmeter Denmark, Alaris Medical Systems) NR 49 15 NR NR 52 14 NR NR NR NR I-II I-II N/A No 2.67 0.5 NR NR 2.75 0.45 NR NR
69 rundshagen2007 Germany single Inclusion: Elective surgery; Exclusion: Neurological diseases, medication affecting the central nervous system, cardiac surgery, neurosurgery, history of drug dependence, alcoholism, pregnancy, known intolerance of used drugs 44 24 20 Narcotrend target D2–E0, propofol/remifentanil titration Clinical monitoring; propofol/remifentanil titration, Narcotrend/BIS recorded but blinded Propofol & Remifentanil Narcotrend (MonitorTechnik) Astra Zeneca; University 48.8 NR NR NR 58 NR NR NR 66.7 60 I-III I-III N/A No 1.85 0.99 NR NR 1.75 0.9 NR NR
70 schulz2007 Germany single Inclusion: all patients with movement disorders scheduled for electrode implantation in the time from December 2002 to April 2003 and from November 2003 to April 2004; Exclusion: age < 18 yr; ASA more than III; inability to communicate with the investigator in German language; patient refusal to participate 21 10 11 BIS target 40–60, propofol titration Clinical assessment (OAA/S 1); propofol titration; BIS recorded but blinded Propofol BIS / Bispectral Index (Aspect Medical Systems) None 61 9.8 NR NR 54.9 10.3 NR NR 20 36.4 I-III I-III N/A No 9.4 1.3 NR NR 9.3 1.1 NR NR
71 shajahan2023A India single Inclusion: aged 18–65 years; American Society of Anesthesiologists (ASA) grade of I-II; scheduled for elective laparoscopic cholecystectomy under general anesthesia. Exclusion: Refusal to participate; hemodynamic instability; cardio-respiratory compromise; hepatic, renal, or metabolic diseases; laparoscopy surgery converted to open cholecystectomy. 74 24 23 BIS target of 48 ± 2, propofol titration Clinical monitoring (OAA/S ≤ 2); propofol titration Sevoflurane & Nitrous Oxide BIS/Bispectral Index (Medtronic) None 45.73 11.4 NR NR 46.26 11.4 NR NR 83.3* 95.7 I-II I-II N/A NR NR NR NR NR NR NR NR NR
72 shajahan2023B India single Inclusion: aged 18–65 years; American Society of Anesthesiologists (ASA) grade of I-II; scheduled for elective laparoscopic cholecystectomy under general anesthesia. Exclusion: Refusal to participate; hemodynamic instability; cardio-respiratory compromise; hepatic, renal, or metabolic diseases; laparoscopy surgery converted to open cholecystectomy. 74 27 23 PSI target 25 ± 2, propofol titration, monitored by SedLine Clinical monitoring (OAA/S ≤ 2); propofol titration Sevoflurane & Nitrous Oxide SedLine/PSI (Masimo) None 42.92 11.72 NR NR 46.26 11.4 NR NR 85.2 95.7 I-II I-II N/A NR NR NR NR NR NR NR NR NR
73 shangne2022 India single Inclusion: 18-60 years; ASA physical status I and II; elective surgeries under general anesthesia; Exclusion: history of cardiac diseases; pregnancy or any serious medical condition that would interfere with Cardio Vascular System (CVS) response; history of allergy to any general anaesthesia drugs; cases lasting less than 30 minutes 92 46 46 BIS target 50±1 for 30 seconds, propofol titration Clinical monitoring (sleep dose); propofol titration Sevoflurane & N2O & Vecuronium NR None 38.37 9.48 NR NR 37.5 8.19 NR NR 54.3 45.7 I-II I-II N/A No 1.3 0.2 NR NR 1.36 0.2 NR NR
74 shi2025A China single Inclusion: age ≥ 60 years; scheduled for elective laparoscopic surgery; expected anesthesia time of >2 hours; grade I to III according to the American Society of Anesthesiologists (ASA) physical status classification; signed informed consent; Exclusion: history of severe neurological or psychiatric disorders; alcohol and drug abuse; severe organ dysfunction; preoperative sleep disorders; received other test drugs or participated in other clinical trials 3 months before surgery; severe hearing and visual impairment that could not cooperate with the examination 83 28 28 BIS target 40-60 (B1), propofol/remifentanil titration Clinical monitoring (HR/BP ±20% baseline); propofol/remifentanil titration; BIS recorded but blinded Propofol & Remifentanil BIS / Bispectral index monitor (Covidien Iic) Project of Improving the Basic Scientific Research Ability of Young and Middle-aged Teachers in Colleges and Universities in Guangxi; Guangxi Medical and Health Key Discipline Cultivation Project 68 5.56 NR NR 67.82 4.73 NR NR 46.4 60.7 I-III I-III N/A No NR NR 3.25 2.1-4.45 NR NR 3.17 2.74-4.03
75 shi2025B China single Inclusion: age ≥ 60 years; scheduled for elective laparoscopic surgery; expected anesthesia time of >2 hours; grade I to III according to the American Society of Anesthesiologists (ASA) physical status classification; signed informed consent; Exclusion: history of severe neurological or psychiatric disorders; alcohol and drug abuse; severe organ dysfunction; preoperative sleep disorders; received other test drugs or participated in other clinical trials 3 months before surgery; severe hearing and visual impairment that could not cooperate with the examination 83 27 28 BIS target 50-60 (B2), propofol/remifentanil titration Clinical monitoring (HR/BP ±20% baseline); propofol/remifentanil titration; BIS recorded but blinded Propofol & Remifentanil BIS / Bispectral index monitor (Covidien Iic) Project of Improving the Basic Scientific Research Ability of Young and Middle-aged Teachers in Colleges and Universities in Guangxi; Guangxi Medical and Health Key Discipline Cultivation Project 68.52 5.42 NR NR 67.82 4.73 NR NR 40.7 60.7 I-III I-III N/A No NR NR 3.24 1.05 NR NR 3.27 1.18
76 singh2009 India single Inclusion: patients scheduled for elective scoliosis surgery; Exclusion: inability to perform the WKPT such as pre-existing neurological deficits, language, comprehension difficulty and mental retardation 30 15 15 BIS target 50-55 (70 for wake-up test), isoflurane/propofol/fentanyl titration Clinical monitoring; isoflurane/propofol/fentanyl titration Isoflurane & Propofol & Fentanyl BIS / Bispectral Index (Aspect Medical Systems) NR 14.5 3.18 NR NR 16.3 6.77 NR NR 40 26.67 NR NR N/A Yes 7 0.3 NR NR 6.83 0.23 NR NR
77 sponholz2019 Germany single Inclusion: elective cardiac surgery with an expected cardiopulmonary bypass (CPB) time≤180 min or elective off-pump coronary artery bypass grafting (OPCAB); age≥18 years; Exclusion: Planned cardiac surgery using hypothermic circulatory support or cardiac arrest; expected CPB time>180 min; non-elective surgery; concurrent interventional trials; refusal to participate 245 122 123 Narcotrend target 37-64, sufentanil/propofol/sevoflurane titration, lowest acceptable dose SOP (sufentanil induction 0.5 μg/kg, maintenance 0.5 μg/kg/h; propofol induction 0.5 mg/kg, maintenance 2.5 mg/kg/h; sevoflurane 0.4 MAC). Clinical monitoring (clinical signs, hemodynamic response, and anesthetic concentration); titration based on local SOP (sufentanil induction 1 μg/kg, maintenance 0.7-1 μg/kg/h; propofol induction 2 mg/kg, maintenance 5 mg/kg/h; sevoflurane 0.5-1 MAC); Narcotrend recorded but blinded. Sufentanil & (Propofol or Sevoflurane) Narcotrend (MonitorTechnik) Jena University Hospital; equipment from Narcotrend NR NR 68 59-75 NR NR 68 62-75 27.9 30.1 NR NR N/A Yes NR NR 3.02 2.43-3.68 NR NR 2.98 2.33-3.70
78 tewari2016 India single Inclusion: ASA class I and II female patients of reproductive age group coming for transvaginal oocyte retrieval (TVOR) under general anesthesia; Exclusion: Known neurological, psychiatric or neuromuscular disorder; patients on anticonvulsants or any other centrally acting medications; patients with facial nerve palsy; history of head injury; congenital or acquired scalp or skull abnormalities; history of substance abuse; obese patients with BMI ≥ 30; history suggestive of hypersensitivity to propofol 120 60 60 Entropy Monitor target SE 40-60, propofol/fentanyl titration, RE-SE gap > 10 used for fentanyl supplementation Clinical monitoring (HR, SBP, RR ±20% baseline); propofol/fentanyl titration, entropy recorded but blinded Propofol & Fentanyl Entropy Module (GE Healthcare) NR 31.5 4.8 NR NR 30.8 3.9 NR NR 100 100 I-II I-II N/A Yes 0.612 0.132 NR NR 0.612 0.232 NR NR
79 thomsen2024 Germany single Inclusion: consenting patients ≥45 years old scheduled for elective vascular surgery with general anesthesia; surgery expected to last at least an hour; estimated intraoperative blood loss <1000 mL; intra-arterial blood pressure monitoring with an arterial catheter planned; Exclusion: previous solid organ transplants; septic; ASA physical status V or VI; pregnant; use of other vasopressors besides norepinephrine during surgery 96 48 48 SedLine Brain Function Monitor (PSI level and SEF95 tracking), anesthetic titration (sevoflurane or propofol) Clinical monitoring (vital signs, clinical perception); anesthetic titration (sevoflurane or propofol); pEEG recorded but blinded (Sevoflurane or Propofol) & (Sufentanil or Remifentanil) SedLine Brain Function Monitor (Masimo) Institutional and/or departmental sources. NR NR 75 70-78 NR NR 74 69-82 29 38 I-IV I-IV ASA V and VI were excluded; specific distribution not reported in Table 1. Yes NR NR 3.58 2.5-5.22 NR NR 3.82 2.7-5.22
80 urfalioglu2017 Turkey single Inclusion: Patients above 18 years, undergoing OPU procedure under general anesthetic before IVF, ASA physical status I–II; Exclusion: comorbid disease, chronic medication use, body mass index ≥30 98 50 48 BIS target 40-60, propofol titration Clinical monitoring (hemodynamic and motor response); propofol titration Propofol & Remifentanil & Sevoflurane BIS-XP/A-2000 (Aspect Medical Systems) None 34.8 5.38 NR NR 34 5.73 NR NR 100 100 I-II I-II N/A Yes NR NR 0.27 0.2-0.35 NR NR 0.27 0.2-0.33
81 vakkuri2005 Finland, Sweden, Norway multi Inclusion: age 18-80 yr; ASA I-III; elective surgery 45-150 min. Exclusion: psychiatric or neurologic disorders; history of major head injury; substance abuse; medication affecting the central nervous system; acquired scalp or skull abnormalities; uncontrolled hypertension; baseline systolic pressure below 90 mmHg; baseline heart rate below 55 beats/min; insulin-dependent diabetes mellitus; renal or hepatic disease; pregnancy; body mass index over 33.0 kg/m2; serious medical condition interfering with cardiovascular response; cardiac, vascular, or cranial neurosurgery; intraoperatively activated epidural analgesia; emergency or other nonelective surgery 320 160 160 Entropy Module target SE 45-65 (SE 65-70 in last 15 min), propofol titration Clinical monitoring (HR/BP ±20% baseline); propofol titration, entropy recorded but blinded Propofol & Nitrous Oxide & Alfentanil Entropy Module/RE and SE (GE Healthcare) Datex-Ohmeda 45 14 NR NR 47 13 NR NR 72.5 75.6 I-III I-III N/A No 1.77 0.8 NR NR 1.78 0.82 NR NR
82 vance2014 USA single Inclusion: elective coronary bypass grafting (CABG), valve replacements, and CABG plus valve replacements; Exclusion: emergency cases; aortic dissections; hypothermic circulatory arrest cases 294 131 163 BIS target > 60 [alert], isoflurane titration, Patients induced with midazolam, fentanyl, pancuronium, with or without propofol or etomidate; maintained with isoflurane, fentanyl, and pancuronium; propofol infusion for transport. MAC (age-adjusted) target < 0.5 [alert]; isoflurane titration Isoflurane & Propofol BIS/Bispectral Index (Covidien) Foundation for Anesthesia Education and Research/American Society of Anesthesiologists; National Institutes of Health; Department of Anesthesiology, University of Michigan NR NR 64 NR NR NR 63 NR 29.8 37.4 NR NR N/A No NR NR 6.05 5.07-7.42 NR NR 5.77 4.83-6.88
83 white2004A USA single Inclusion: healthy outpatients scheduled to undergo gynecologic laparoscopic surgery under general anesthesia; Exclusion: known neurologic or psychiatric disorders; patients currently using anticonvulsants or other centrally active medications; clinically significant cardiovascular, respiratory, hepatic, renal or metabolic disease; long-term drug or alcohol abuse; body weight greater than 50% above their ideal body weight 60 20 20 BIS target 50-60, desflurane titration Clinical monitoring (clinical signs, hemodynamic stability); desflurane titration; BIS recorded but blinded Desflurane & Nitrous oxide BIS/Bispectral Index (Aspect Medical Systems, Inc.) Alaris Medical Systems; Margaret Milam McDermott Distinguished Chair in Anesthesiology; White Mountain Institute 54 14 NR NR 48 10 NR NR 100 100 I-III I-II N/A No 0.97 0.37 NR NR 1.1 0.27 NR NR
84 white2004B USA single Inclusion: healthy outpatients scheduled to undergo gynecologic laparoscopic surgery under general anesthesia; Exclusion: known neurologic or psychiatric disorders; patients currently using anticonvulsants or other centrally active medications; clinically significant cardiovascular, respiratory, hepatic, renal or metabolic disease; long-term drug or alcohol abuse; body weight greater than 50% above their ideal body weight 60 20 20 AAI target 15-25, desflurane titration Clinical monitoring (clinical signs, hemodynamic stability); desflurane titration; AAI recorded but blinded Desflurane & Nitrous oxide AAI/AEP (Alaris Medical Systems) Alaris Medical Systems; Margaret Milam McDermott Distinguished Chair in Anesthesiology; White Mountain Institute 50 15 NR NR 48 10 NR NR 100 100 I-III I-II N/A No 0.92 0.45 NR NR 1.1 0.27 NR NR
85 whitlock2014 USA single Inclusion: Increased risk for intraoperative awareness (planned open heart surgery, ejection fraction <40%, history of intraoperative awareness, difficult intubation, ASA physical status 4 or 5, aortic stenosis, end-stage lung disease, pulmonary hypertension, marginal exercise tolerance, or daily use of neuroactive medications or alcohol); Exclusion: Significant neurological disease 310 149 161 BIS-guided (alerts for BIS >60 or BIS <40) ETAC-guided (alerts for <0.7 or >1.3 age-adjusted minimum alveolar concentration [MAC]) Volatile anesthetic agents BIS/Bispectral Index (Covidien) Foundation for Anesthesia Education and Research; American Society of Anesthesiologists; National Center for Research Resources; National Institutes of Health 62 14 NR NR 61 14 NR NR 37.6 37.3 NR NR ASA score distribution by randomization group not reported; total population included ASA 1-5 Yes 5.18 1.47 NR NR 5.32 1.53 NR NR
86 wildes2016 USA single Inclusion: Patients ≥ 60 years undergoing major elective surgery with general anesthesia and anticipated hospital stay > 2 days; Exclusion: Neurosurgical procedures, preoperative delirium, inability to participate in delirium screening, history of intraoperative awareness, planned second surgery within 5 days 1232 616 616 BIS target ≥40, volatile anaesthesia titration, instructed to regularly inspect the raw EEG waveform to avoid burst suppression; audible low-BIS alarm set at 40. Clinical monitoring; usual care volatile anaesthesia titration; EEG sensors applied but clinicians blinded to indices; audible alarm for volatile agent at 0.3 MAC. Volatile anaesthetic agent BIS (Medtronic) National Institute on Aging; Barnes-Jewish Hospital Foundation; Department of Anesthesiology at Washington University NR NR NR NR NR NR NR NR NR NR I-IV I-IV N/A No NR NR NR NR NR NR NR NR
87 wildes2019 USA single Inclusion: aged 60 years and older; undergoing major surgery with general anesthesia; Exclusion: unable to provide informed consent; delirious; blind; deaf; illiterate; not fluent in English; history of intraoperative awareness; scheduled for a second surgery within 5 days of the initial surgery 1213 604 609 Bispectral Index (BIS) Quatro target 40-100 (typically >40), volatile anesthetic titration, feedback on EEG suppression (SR >1%) and waveforms provided. Clinical monitoring; clinicians blinded to EEG waveforms and BIS values except for Signal Quality Index. Volatile agent Bispectral Index Quatro (Medtronic) National Institutes of Health; Dr Seymour and Rose T. Brown Endowed Chair at Washington University NR NR 69.5 65.0-74.7 NR NR 69.4 64.7-75.8 45.9 45.5 I-VI I-VI ASA score reported as percentage >3 (severe systemic disease), range not explicitly provided for each group No NR NR 4.41 3.2-5.73 NR NR 4.4 3.1-5.82
88 wu2008 Taiwan single Inclusion: ASA physical status I or II, scheduled for total knee replacement; Exclusion: history of cerebrovascular disease, treatment with psychoactive medication, existing cardiac dysrhythmia, weight less than 70% or more than 130% of ideal body weight 65 34 31 M-Entropy Module target 35–45 (SE/RE) and 5-10 (gradient), sevoflurane titration Clinical signs and hemodynamic monitoring (HR/MAP ±30% baseline); sevoflurane titration Sevoflurane M-Entropy Module/S/5 Entropy Module (GE Datex-Ohmeda) National Science Council 68.03 6.1 NR NR 68.9 6.5 NR NR 17.6 19.4 I-II I-II N/A No 2.23 0.5 NR NR 2.41 0.5 NR NR
89 wu2021A Taiwan single Inclusion: age 20 to 65 years; body mass index equal to or greater than 30 kg· m− 2; undergoing laparoscopic sleeve gastrectomy; Exclusion: use of hypnotics or antipsychotics within 30 days before surgery; known cerebrovascular disease; stage 4 or 5 chronic kidney disease; significant cardiovascular disease; peripheral capillary oxygen saturation < 90% in room air; pregnant women; patient refusal 40 20 20 M-Entropy guidance target 40-60, sevoflurane titration Clinical monitoring (HR/BP ±20% baseline); sevoflurane titration; M-Entropy recorded but blinded Sevoflurane M-Entropy/S/5 (GE Healthcare) Taipei Medical University; Ministry of Science and Technology 37.9 10.7 NR NR 38 7.3 NR NR 35 40 II-III II-III Pooled from multiple arms (SEVO with M-Entropy + DES with M-Entropy for pEEG; SEVO without + DES without for Control) No NR NR 1.93 1.67-2.25 NR NR 2 1.83-2.47
90 wu2021B Taiwan single Inclusion: age 20 to 65 years; body mass index equal to or greater than 30 kg· m− 2; undergoing laparoscopic sleeve gastrectomy; Exclusion: use of hypnotics or antipsychotics within 30 days before surgery; known cerebrovascular disease; stage 4 or 5 chronic kidney disease; significant cardiovascular disease; peripheral capillary oxygen saturation < 90% in room air; pregnant women; patient refusal 40 20 20 M-Entropy guidance target 40-60, desflurane titration Clinical monitoring (HR/BP ±20% baseline); desflurane titration; M-Entropy recorded but blinded Desflurane M-Entropy/S/5 (GE Healthcare) Taipei Medical University; Ministry of Science and Technology 33.9 7.5 NR NR 37 10.5 NR NR 60 45 NR NR N/A No NR NR 2.13 1.52-2.43 NR NR 2.05 1.67-2.50
91 yan2018A China single Inclusion: severe TBI without other organ injury; Age ranging from 18 to 60 years; Admission Glasgow Coma Scale score ranging from 5 to 8; BIS greater than 60 and RASS value greater than -2 before sedation therapy. Exclusion: Patients with other organ function failure; Patients with severe TBI with unknown cause of injury; medical history of moderate or severe TBI; epileptic seizures or family history of epilepsy; psychiatric disorders; history of alcoholism; forehead skin defects; continual hypotension. 37 12 15 BIS target 40–50, propofol/midazolam titration Clinical monitoring (RASS target -2 or -3); propofol/midazolam titration Propofol & Midazolam BIS/Bispectral Index (Medtronic and Aspect Medical Systems and Philips) None 36.67 15.32 NR NR 37 14.56 NR NR 50 33.3 NR NR N/A No NR NR NR NR NR NR NR NR
92 yan2018B China single Inclusion: severe TBI without other organ injury; Age ranging from 18 to 60 years; Admission Glasgow Coma Scale score ranging from 5 to 8; BIS greater than 60 and RASS value greater than -2 before sedation therapy. Exclusion: Patients with other organ function failure; Patients with severe TBI with unknown cause of injury; medical history of moderate or severe TBI; epileptic seizures or family history of epilepsy; psychiatric disorders; history of alcoholism; forehead skin defects; continual hypotension. 37 10 15 BIS target 50–60, propofol/midazolam titration Clinical monitoring (RASS target -2 or -3); propofol/midazolam titration Propofol & Midazolam BIS/Bispectral Index (Medtronic and Aspect Medical Systems and Philips) None 42.7 16.3 NR NR 37 14.56 NR NR 40 33.3 NR NR N/A No NR NR NR NR NR NR NR NR
93 zhang2011 China multi Inclusion: Patients (≥18 years of age) undergoing TIVA, without any apparent mental defect; Exclusion: patients not able to get interviewed after surgery, unable to communicate in mandarin Chinese, under awake intubation, or undergoing intraoperative arousal test. 5228 2919 2309 BIS target 40–60, propofol titration Clinical monitoring (clinical experiences and vital signs); propofol titration; BIS recorded but blinded Propofol A-2000 BIS/Bispectral Index (Aspect Medical Systems) None 46.95 14.86 NR NR 46.06 14.59 NR NR 57.2 57.4 I-≥III I-≥III Upper limit reported as '>3' in table and 'equal to or greater than 3' in text. Extracted as III but likely includes higher classes. No NR NR NR NR NR NR NR NR
94 zhang2016A China single Inclusion: severe burns (total area of 31%~50%, III degree burn area of 11%~20%, or total area <31% but combined with shock, compound injury, associated injury, and/or severe inhalation injury); “escharotomy + dermatoplasty” under general anesthesia during early stage (within 7 days after burn); 18-65 years of age; 20<BMI<30; no history of primary hypertension; Exclusion: pre-operative heart, lung, liver, kidney and other viscera insufficiency; elective surgery; other serious complications, such as myocardial infarction, cerebral infarction, etc. 108 36 36 BIS target 40-65, propofol/remifentanil titration Clinical monitoring (SBP 90-140 mmHg); propofol/remifentanil titration Propofol & Remifentanil BIS (Medtronic) NR 47.17 14.79 NR NR 46.92 13.81 NR NR 41.67 44.44 NR NR N/A No NR NR NR NR NR NR NR NR
95 zhang2016B China single Inclusion: severe burns (total area of 31%~50%, III degree burn area of 11%~20%, or total area <31% but combined with shock, compound injury, associated injury, and/or severe inhalation injury); “escharotomy + dermatoplasty” under general anesthesia during early stage (within 7 days after burn); 18-65 years of age; 20<BMI<30; no history of primary hypertension; Exclusion: pre-operative heart, lung, liver, kidney and other viscera insufficiency; elective surgery; other serious complications, such as myocardial infarction, cerebral infarction, etc. 108 36 36 Narcotrend target D2 to E0, propofol/remifentanil titration Clinical monitoring (SBP 90-140 mmHg); propofol/remifentanil titration Propofol & Remifentanil Narcotrend (Hannover Medical University) NR 46.92 13.81 NR NR 46.92 13.81 NR NR 47.22 44.44 NR NR N/A No NR NR NR NR NR NR NR NR
96 zhou2018 China single Inclusion: ASA I–III; age 65–75 years; MMSE score >27 points; normal vision or corrected visual acuity; duration of surgery expected to be two hours or more; anticipated postoperative hospital stay of at least seven days; Exclusion: Parkinson’s disease; history of transient ischemic attack (TIA) or stroke; liver or renal insufficiency; Alzheimer’s disease; visual or sensory disturbance; language difficulties or significant hearing impairment; use of drugs affecting cognitive function 81 41 40 BIS target 40–60, propofol titration Clinical monitoring (HR/BP ±20% baseline); propofol titration; BIS recorded but blinded Propofol & Remifentanil NR Department of Anesthesiology, First Affiliated Hospital, Anhui Medical University 68.29 2.81 NR NR 68.9 2.99 NR NR 29.3 32.5 I-III I-III ASA range reported in inclusion criteria only; specific breakdown per group not provided in results. No 3.09 0.245 NR NR 3.08 0.23 NR NR

Insights

31 found
Correlations 5 Columns that move together (r² > 0.25)
Outliers 6 Values > 3σ from the mean
Distributions 6 One value dominates (>60%)
Data Quality 1 Missing or empty values
Systematic review data extraction of 96 RCTs comparing pEEG-guided vs. standard anesthesia monitoring, covering 31,662 patients across 22 countries.

This dataset contains 96 records across 34 fields: paper, country, center_type, enrollment_criteria, sample_size_total, sample_size_peeg, and 28 more.