Sedation During Lower Extremity Surgery Under Spinal AnesthesiaPhase 4NCT07863063
Remimazolam Concentration and Sedation Depth During Lower Extremity Surgery Under Spinal Anesthesia
A Phase 4 study testing Remimazolam in people with Sedation During Lower Extremity Surgery Under Spinal Anesthesia, run by Seoul National University Hospital at 1 site in South Korea.
Trial summary
This study will examine how the amount of remimazolam predicted to reach its site of action relates to the depth of sedation during lower extremity surgery under spinal anesthesia. Remimazolam is a sedative used to help patients relax and feel sleepy during surgery. Read more about this study
- Who is it for?
- Ages 19 years and older
- Conditions the study is for
- Sedation During Lower Extremity Surgery Under Spinal Anesthesia
- What is being tested?
- Remimazolam
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteSouth Korea
- Study dates
- 30 Oct 2026to Oct 2027
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 19 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age 19 years or older.
- Scheduled for lower extremity surgery under spinal anesthesia.
- American Society of Anesthesiologists (ASA) physical status I-III.
- Agrees to intraoperative sedation and provides written informed consent.
Who cannot join
- Refusal to participate.
- Contraindication to spinal anesthesia, including refusal, increased intracranial pressure, infection at the puncture site, underlying neurological disease, severe hypovolemia, aortic or mitral stenosis, thrombocytopenia, or coagulopathy.
- Contraindication or history of hypersensitivity to remimazolam, including acute narrow-angle glaucoma, severe respiratory failure, or dextran 40 hypersensitivity.
- Contraindication or history of hypersensitivity to flumazenil.
- Body weight below 40 kg.
- Baseline Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score of 4 or lower.
Show all 11Show fewer
- Central nervous system disease or cognitive impairment that makes MOAA/S assessment unreliable.
- Regular use of psychotropic medications, including benzodiazepines.
- Pregnancy.
- Other circumstances judged unsuitable by the investigator.
- Only adults capable of providing informed consent are included. Employees and students are not included, as specified in the protocol.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
South Korea1 site
Seoul National University Hospital
Seoul
Hansol Kim, MD, +82-2-2072-2467, hansolfrkr@gmail.com
Hansol Kim, MD
About this study
Official title: Relationship Between Model-Predicted Effect-Site Concentration and Sedation Depth During Titrated Remimazolam Sedation for Lower Extremity Surgery Under Spinal Anesthesia: An Age-Stratified Prospective Study
This study will examine how the amount of remimazolam predicted to reach its site of action relates to the depth of sedation during lower extremity surgery under spinal anesthesia. Remimazolam is a sedative used to help patients relax and feel sleepy during surgery. People may respond differently to the same amount of this medicine, and age may explain some of these differences.
Sixty adults will be enrolled at Seoul National University Hospital, with 20 participants in each age group: 19-49 years, 50-69 years, and 70 years or older. All participants will receive remimazolam using the same stepwise dose-adjustment rules. The dose will be adjusted according to repeated assessments of responsiveness. Researchers will record sedation scores, medication delivery, brain-wave signals, vital signs, recovery, and side effects.
After surgery, a computer model will estimate the remimazolam concentration at its site of action. These estimates will not be available to the clinical team during surgery. The main goal is to measure how much the concentration associated with the target level of sedation varies between patients. The study will also examine the effect of age and whether early responses can help predict an individual patient's later response.
Read the detailed description
This is a single-center, prospective, single-arm, open-label study with age-stratified enrollment. Age strata are used to achieve a balanced age distribution rather than to define randomized treatment groups. Age will be modeled as a continuous covariate.
The study evaluates the concentration-response relationship during standardized titrated remimazolam sedation under spinal anesthesia. The Eleveld pharmacokinetic/pharmacodynamic model will be used after surgery to reconstruct model-predicted effect-site concentrations from recorded drug administration histories and patient covariates under the no-opioid condition. Model predictions will not be provided to the treating anesthesiologist or sedation assessor during surgery. Four-channel frontal electroencephalography and processed indices will be recorded in the operating room; recovery-room assessments will use clinical sedation scores without electroencephalography.
The principal analysis will use an ordinal mixed-effects model relating model-predicted effect-site concentration to the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score. Between-patient variability will be expressed as a coefficient of variation, with population Ce50 and confidence intervals reported for interpretation. Age-related and residual between-patient variability will be evaluated separately. Concentration phase (rising, stable, or falling) and elapsed infusion time will be considered, and sex and body weight will be examined as additional covariates.
The analysis set will include participants with at least one evaluable concentration-sedation observation. If another sedative is required after failure to reach the target at the maximum remimazolam rate, observations before the switch will remain eligible for analysis; subsequent sedation and electroencephalographic data will be excluded from the pharmacodynamic analysis. Early observations within 5 minutes after loading will be used to explore individualized prediction of later responses. Exploratory electroencephalographic analyses will assess associations of spectral and other signal features with sedation scores and model-predicted concentrations. No interim analysis or missing-data imputation is planned. Adverse events will be assessed through 24 hours after surgery.
- Being tested
- Remimazolam
- Keywords
- Remimazolam, Spinal anesthesia, Effect-site concentration, Sedation depth, Pharmacodynamics, Electroencephalography
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
RemimazolamDrug
Also called Byfavo
Remimazolam besylate is prepared at 1 mg/mL. After spinal anesthesia, 2.5 mg is infused intravenously over 1 minute, followed by 0.2 mg/kg/h. MOAA/S is assessed at 1-5 minutes after loading and then every 5 minutes. Increase by 0.05 mg/kg/h for MOAA/S >3; decrease by 0.05 mg/kg/h for MOAA/S <=2, maintaining the minimum rate if already at 0.05 mg/kg/h. Permitted range: 0.05-0.8 mg/kg/h. Stop infusion for MOAA/S <=1 or airway/respiratory impairment; resume at the minimum rate after recovery, with flumazenil if clinically indicated. Stop remimazolam and consider another sedative if MOAA/S remains >3 at the maximum rate. Stop infusion at the start of muscle-layer closure. Assess MOAA/S every 5 minutes after cessation until MOAA/S 5. Opioids and other sedatives are not coadministered during the study regimen.
| Study group | Role | What they receive |
|---|---|---|
| Titrated Remimazolam Sedation | Experimental | All participants undergo lower extremity surgery under spinal anesthesia and receive intravenous remimazolam titrated to a Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score of 3. A fixed 2.5 mg loading dose is administered over 1 minute, followed by 0.2 mg/kg/h. The infusion is adjusted in 0.05 mg/kg/h steps at 5-minute assessments within a range of 0.05-0.8 mg/kg/h. Infusion is stopped at the start of muscle-layer closure, and recovery is assessed until MOAA/S 5. Age-stratified enrollment does not create separate treatment arms. Receives: Drug: Remimazolam |
What is being measured
The primary outcome is the main question the study is designed to answer.
Between-Patient Coefficient of Variation in Model-Predicted Effect-Site Concentration Associated With Target Sedation
Between-patient variability in the remimazolam effect-site concentration associated with target sedation (Modified Observer's Assessment of Alertness/Sedation [MOAA/S] <=3), expressed as a coefficient of variation (%). Eleveld model-predicted concentrations are reconstructed after surgery from dosing histories and patient covariates. The protocol specifies maintenance observations at MOAA/S 3 and an ordinal mixed-effects concentration-response analysis to estimate variability at the MOAA/S <=3 threshold. MOAA/S ranges from 0 (no response to painful stimulus) to 5 (readily responsive to a name spoken in a normal tone); lower scores indicate deeper sedation.
Measured: During intraoperative remimazolam sedation, from loading through infusion cessation on the day of surgery
Secondary outcomes (34)
Ratio of Individual Representative Effect-Site Concentration to the Eleveld Sedation Target
For each participant, the median model-predicted effect-site concentration at maintenance MOAA/S 3 observations divided by the Eleveld model sedation target (1.75 times the age-adjusted Ce50).
Measured: During remimazolam administration on the day of surgery
Age-Adjusted Residual Between-Patient Coefficient of Variation
Residual between-patient variability in the concentration associated with target sedation after adjustment for age as a continuous covariate, expressed as a coefficient of variation (%).
Measured: During remimazolam administration on the day of surgery
MOAA/S Score
Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score, measured at baseline before remimazolam, at 1, 2, 3, 4, and 5 minutes after completion of loading, every 5 minutes during infusion, and every 5 minutes after infusion cessation until a score of 5 is reached in the operating room or PACU. Scores are also recorded at infusion cessation, end of surgery, operating-room discharge, and PACU admission. MOAA/S ranges from 0 (no response to painful stimulation) to 5 (readily responds to a name spoken in a normal tone); lower scores indicate deeper sedation.
Measured: From baseline before remimazolam until MOAA/S 5 after infusion cessation on the day of surgery
Remimazolam Infusion Rate
Remimazolam infusion rate (mg/kg/h), measured at 5-minute intervals from the end of the loading dose until infusion cessation. The rate after any adjustment at each assessment is recorded.
Measured: From the end of the remimazolam loading dose until infusion cessation on the day of surgery
Number of Dose Increases Before Target Sedation
Number of infusion-rate increases required before reaching target sedation (MOAA/S <=3).
Measured: During remimazolam administration on the day of surgery
Maintenance Infusion-Rate Distribution
Distribution of remimazolam infusion rates during maintenance, expressed in mg/kg/h.
Measured: During remimazolam administration on the day of surgery
Failure to Achieve Target Sedation at the Maximum Infusion Rate
Number and proportion with persistent MOAA/S >3 at 0.8 mg/kg/h requiring discontinuation of remimazolam or a change of sedative.
Measured: During remimazolam administration on the day of surgery
Total Remimazolam Dose
Total intravenous remimazolam administered, in milligrams.
Measured: During remimazolam administration on the day of surgery
Incidence of Paradoxical Reactions
Number and proportion with agitation, increased movement, restlessness, or disinhibited speech despite increasing remimazolam infusion rates.
Measured: During remimazolam administration on the day of surgery
Richmond Agitation-Sedation Scale Score During Paradoxical Reactions
Richmond Agitation-Sedation Scale (RASS) scores recorded when paradoxical reactions occur. RASS ranges from -5 (unarousable) to +4 (combative), with 0 indicating alert and calm.
Measured: During remimazolam administration on the day of surgery
Raw EEG Data
Four-channel frontal raw electroencephalographic (EEG) signals recorded continuously using a Masimo SedLine sensor. The time-stamped signals are stored for offline analysis.
Measured: From SedLine sensor placement before sedation until operating-room discharge on the day of surgery
Hypoxemia
Proportion of participants with peripheral oxygen saturation (SpO2) below 95%.
Measured: During surgery and PACU recovery on the day of surgery
Jaw Thrust
Proportion of participants requiring a jaw-thrust maneuver to maintain airway patency.
Measured: During surgery and PACU recovery on the day of surgery
Postanesthesia Care Unit Length of Stay
Elapsed time in minutes from admission to discharge from the postanesthesia care unit.
Measured: From postanesthesia care unit admission to discharge on the day of surgery
Patient Satisfaction With Intraoperative Sedation
Overall satisfaction with sedation rated by the participant on a 0-10 numerical scale. Higher scores indicate greater satisfaction.
Measured: Before PACU discharge on the day of surgery
Hypotension
Proportion of participants with mean arterial pressure below 65 mmHg.
Measured: During surgery on the day of surgery
Flumazenil Administration
Number and proportion of participants receiving flumazenil and frequency of administration.
Measured: During surgery and postanesthesia recovery on the day of surgery
Patient State Index (PSI)
Patient State Index (PSI) measured using the Masimo SedLine system. PSI is recorded continuously, with values collected at 5-minute intervals alongside intraoperative MOAA/S assessments. The index ranges from 0 to 100; lower values generally indicate a deeper hypnotic state.
Measured: From SedLine sensor placement before sedation until operating-room discharge on the day of surgery
Bradycardia
Proportion of participants with heart rate below 45 beats/min.
Measured: During surgery on the day of surgery
Tachycardia
Proportion of participants with heart rate above 110 beats/min.
Measured: During surgery on the day of surgery
Apnea
Proportion of participants with apnea lasting at least 30 seconds, assessed by end-tidal carbon dioxide monitoring.
Measured: During surgery and PACU recovery on the day of surgery
Nasopharyngeal Airway Insertion
Proportion of participants requiring insertion of a nasopharyngeal airway.
Measured: During surgery and PACU recovery on the day of surgery
Oropharyngeal Airway Insertion
Proportion of participants requiring insertion of an oropharyngeal airway.
Measured: During surgery and PACU recovery on the day of surgery
Positive-Pressure Ventilation
Proportion of participants requiring positive-pressure ventilation to support breathing.
Measured: During surgery and PACU recovery on the day of surgery
Tracheal Intubation
Proportion of participants requiring unplanned tracheal intubation for airway or respiratory support.
Measured: During surgery and PACU recovery on the day of surgery
Supplemental Oxygen Escalation
Proportion of participants requiring new or increased supplemental oxygen for a sedation-related respiratory event. Planned routine oxygen administration is not counted as an adverse-event intervention.
Measured: During surgery and PACU recovery on the day of surgery
Infusion Interruption for Oversedation
Proportion of participants whose remimazolam infusion is interrupted because of oversedation (MOAA/S <=1).
Measured: During remimazolam infusion on the day of surgery
Nausea
Proportion of participants reporting nausea.
Measured: From remimazolam administration through 24 hours after surgery
Vomiting
Proportion of participants experiencing vomiting, recorded separately from nausea.
Measured: From remimazolam administration through 24 hours after surgery
Hiccups
Proportion of participants experiencing hiccups.
Measured: From remimazolam administration through 24 hours after surgery
Hypersensitivity Reaction
Proportion of participants experiencing a clinically identified hypersensitivity reaction.
Measured: From remimazolam administration through 24 hours after surgery
Headache
Proportion of participants reporting headache.
Measured: From remimazolam administration through 24 hours after surgery
Dizziness
Proportion of participants reporting dizziness.
Measured: From remimazolam administration through 24 hours after surgery
Respiratory Depression in the PACU
Proportion of participants with respiratory depression identified by the clinical team during PACU recovery.
Measured: From PACU admission to PACU discharge on the day of surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Oct 2026
- Study start30 Oct 2026 (estimated)
- Primary completionOct 2027 (estimated)
- Study completionOct 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Sedation During Lower Extremity Surgery Under Spinal AnesthesiaStudies of the same condition, open and under way.
- More trials run by Seoul National University HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Single-center, prospective, single-arm, open-label study with 60 participants. Enrollment is stratified by age (19-49, 50-69, and 70 years or older; 20 participants per stratum) to ensure a balanced age distribution. All participants receive the same standardized remimazolam titration protocol. There is no randomization or comparator group; age is analyzed as a continuous covariate.
- Masking
- None (open label)
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Seoul National University Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- National Research Foundation of Korea, Ministry of Science and ICT, Republic of Korea
- Responsible party
- Principal investigator, Hansol Kim, MD, Seoul National University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07863063
- Other IDs
- RS-2026-25596557
- Status last verified
- Sep 2026
- First submitted
- 28 Sep 2026
- Last updated
- 13 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 13 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Relationship Between Model-Predicted Effect-Site Concentration and Sedation Depth During Titrated Remimazolam Sedation for Lower Extremity Surgery Under Spinal Anesthesia: An Age-Stratified Prospective Study
- ClinicalTrials.gov ID
- NCT07863063
- Keywords
- Remimazolam, Spinal anesthesia, Effect-site concentration, Sedation depth, Pharmacodynamics, Electroencephalography
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Seoul National University HospitalUniversity, hospital or other
- Collaborators
- National Research Foundation of Korea, Ministry of Science and ICT, Republic of Korea
- Study start
- 30 Oct 2026 (estimated)
- Primary completion
- Oct 2027 (estimated)
- Study completion
- Oct 2027 (estimated)
- First posted
- 7 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will examine how the amount of remimazolam predicted to reach its site of action relates to the depth of sedation during lower extremity surgery under spinal anesthesia. Remimazolam is a sedative used to help patients relax and feel sleepy during surgery. People may respond differently to the same amount of this medicine, and age may explain some of these differences.
Sixty adults will be enrolled at Seoul National University Hospital, with 20 participants in each age group: 19-49 years, 50-69 years, and 70 years or older. All participants will receive remimazolam using the same stepwise dose-adjustment rules. The dose will be adjusted according to repeated assessments of responsiveness. Researchers will record sedation scores, medication delivery, brain-wave signals, vital signs, recovery, and side effects.
After surgery, a computer model will estimate the remimazolam concentration at its site of action. These estimates will not be available to the clinical team during surgery. The main goal is to measure how much the concentration associated with the target level of sedation varies between patients. The study will also examine the effect of age and whether early responses can help predict an individual patient's later response.
Detailed description
This is a single-center, prospective, single-arm, open-label study with age-stratified enrollment. Age strata are used to achieve a balanced age distribution rather than to define randomized treatment groups. Age will be modeled as a continuous covariate.
The study evaluates the concentration-response relationship during standardized titrated remimazolam sedation under spinal anesthesia. The Eleveld pharmacokinetic/pharmacodynamic model will be used after surgery to reconstruct model-predicted effect-site concentrations from recorded drug administration histories and patient covariates under the no-opioid condition. Model predictions will not be provided to the treating anesthesiologist or sedation assessor during surgery. Four-channel frontal electroencephalography and processed indices will be recorded in the operating room; recovery-room assessments will use clinical sedation scores without electroencephalography.
The principal analysis will use an ordinal mixed-effects model relating model-predicted effect-site concentration to the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score. Between-patient variability will be expressed as a coefficient of variation, with population Ce50 and confidence intervals reported for interpretation. Age-related and residual between-patient variability will be evaluated separately. Concentration phase (rising, stable, or falling) and elapsed infusion time will be considered, and sex and body weight will be examined as additional covariates.
The analysis set will include participants with at least one evaluable concentration-sedation observation. If another sedative is required after failure to reach the target at the maximum remimazolam rate, observations before the switch will remain eligible for analysis; subsequent sedation and electroencephalographic data will be excluded from the pharmacodynamic analysis. Early observations within 5 minutes after loading will be used to explore individualized prediction of later responses. Exploratory electroencephalographic analyses will assess associations of spectral and other signal features with sedation scores and model-predicted concentrations. No interim analysis or missing-data imputation is planned. Adverse events will be assessed through 24 hours after surgery.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Single-center, prospective, single-arm, open-label study with 60 participants. Enrollment is stratified by age (19-49, 50-69, and 70 years or older; 20 participants per stratum) to ensure a balanced age distribution. All participants receive the same standardized remimazolam titration protocol. There is no randomization or comparator group; age is analyzed as a continuous covariate.
| Arm | Type | Receives |
|---|---|---|
| Titrated Remimazolam Sedation | Experimental | Drug: RemimazolamAll participants undergo lower extremity surgery under spinal anesthesia and receive intravenous remimazolam titrated to a Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score of 3. A fixed 2.5 mg loading dose is administered over 1 minute, followed by 0.2 mg/kg/h. The infusion is adjusted in 0.05 mg/kg/h steps at 5-minute assessments within a range of 0.05-0.8 mg/kg/h. Infusion is stopped at the start of muscle-layer closure, and recovery is assessed until MOAA/S 5. Age-stratified enrollment does not create separate treatment arms. |
Who may qualify
- Ages
- 19 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Age 19 years or older.
- Scheduled for lower extremity surgery under spinal anesthesia.
- American Society of Anesthesiologists (ASA) physical status I-III.
- Agrees to intraoperative sedation and provides written informed consent.
Key exclusion criteria (11 listed)
- Refusal to participate.
- Contraindication to spinal anesthesia, including refusal, increased intracranial pressure, infection at the puncture site, underlying neurological disease, severe hypovolemia, aortic or mitral stenosis, thrombocytopenia, or coagulopathy.
- Contraindication or history of hypersensitivity to remimazolam, including acute narrow-angle glaucoma, severe respiratory failure, or dextran 40 hypersensitivity.
- Contraindication or history of hypersensitivity to flumazenil.
- Body weight below 40 kg.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| RemimazolamAlso: ByfavoRemimazolam besylate is prepared at 1 mg/mL. After spinal anesthesia, 2.5 mg is infused intravenously over 1 minute, followed by 0.2 mg/kg/h. MOAA/S is assessed at 1-5 minutes after loading and then every 5 minutes. Increase by 0.05 mg/kg/h for MOAA/S >3; decrease by 0.05 mg/kg/h for MOAA/S <=2, maintaining the minimum rate if already at 0.05 mg/kg/h. Permitted range: 0.05-0.8 mg/kg/h. Stop infusion for MOAA/S <=1 or airway/respiratory impairment; resume at the minimum rate after recovery, with flumazenil if clinically indicated. Stop remimazolam and consider another sedative if MOAA/S remains >3 at the maximum rate. Stop infusion at the start of muscle-layer closure. Assess MOAA/S every 5 minutes after cessation until MOAA/S 5. Opioids and other sedatives are not coadministered during the study regimen. | Drug | Titrated Remimazolam Sedation |
Primary outcome
Between-Patient Coefficient of Variation in Model-Predicted Effect-Site Concentration Associated With Target Sedation
Time frame: During intraoperative remimazolam sedation, from loading through infusion cessation on the day of surgery
Between-patient variability in the remimazolam effect-site concentration associated with target sedation (Modified Observer's Assessment of Alertness/Sedation [MOAA/S] <=3), expressed as a coefficient of variation (%). Eleveld model-predicted concentrations are reconstructed after surgery from dosing histories and patient covariates. The protocol specifies maintenance observations at MOAA/S 3 and an ordinal mixed-effects concentration-response analysis to estimate variability at the MOAA/S <=3 threshold. MOAA/S ranges from 0 (no response to painful stimulus) to 5 (readily responsive to a name spoken in a normal tone); lower scores indicate deeper sedation.
34 secondary outcomes
Ratio of Individual Representative Effect-Site Concentration to the Eleveld Sedation Target
Time frame: During remimazolam administration on the day of surgery
Age-Adjusted Residual Between-Patient Coefficient of Variation
Time frame: During remimazolam administration on the day of surgery
MOAA/S Score
Time frame: From baseline before remimazolam until MOAA/S 5 after infusion cessation on the day of surgery
Remimazolam Infusion Rate
Time frame: From the end of the remimazolam loading dose until infusion cessation on the day of surgery
Number of Dose Increases Before Target Sedation
Time frame: During remimazolam administration on the day of surgery
Maintenance Infusion-Rate Distribution
Time frame: During remimazolam administration on the day of surgery
Failure to Achieve Target Sedation at the Maximum Infusion Rate
Time frame: During remimazolam administration on the day of surgery
Total Remimazolam Dose
Time frame: During remimazolam administration on the day of surgery
Incidence of Paradoxical Reactions
Time frame: During remimazolam administration on the day of surgery
Richmond Agitation-Sedation Scale Score During Paradoxical Reactions
Time frame: During remimazolam administration on the day of surgery
Raw EEG Data
Time frame: From SedLine sensor placement before sedation until operating-room discharge on the day of surgery
Hypoxemia
Time frame: During surgery and PACU recovery on the day of surgery
Jaw Thrust
Time frame: During surgery and PACU recovery on the day of surgery
Postanesthesia Care Unit Length of Stay
Time frame: From postanesthesia care unit admission to discharge on the day of surgery
Patient Satisfaction With Intraoperative Sedation
Time frame: Before PACU discharge on the day of surgery
Hypotension
Time frame: During surgery on the day of surgery
Flumazenil Administration
Time frame: During surgery and postanesthesia recovery on the day of surgery
Patient State Index (PSI)
Time frame: From SedLine sensor placement before sedation until operating-room discharge on the day of surgery
Bradycardia
Time frame: During surgery on the day of surgery
Tachycardia
Time frame: During surgery on the day of surgery
Apnea
Time frame: During surgery and PACU recovery on the day of surgery
Nasopharyngeal Airway Insertion
Time frame: During surgery and PACU recovery on the day of surgery
Oropharyngeal Airway Insertion
Time frame: During surgery and PACU recovery on the day of surgery
Positive-Pressure Ventilation
Time frame: During surgery and PACU recovery on the day of surgery
Tracheal Intubation
Time frame: During surgery and PACU recovery on the day of surgery
Supplemental Oxygen Escalation
Time frame: During surgery and PACU recovery on the day of surgery
Infusion Interruption for Oversedation
Time frame: During remimazolam infusion on the day of surgery
Nausea
Time frame: From remimazolam administration through 24 hours after surgery
Vomiting
Time frame: From remimazolam administration through 24 hours after surgery
Hiccups
Time frame: From remimazolam administration through 24 hours after surgery
Hypersensitivity Reaction
Time frame: From remimazolam administration through 24 hours after surgery
Headache
Time frame: From remimazolam administration through 24 hours after surgery
Dizziness
Time frame: From remimazolam administration through 24 hours after surgery
Respiratory Depression in the PACU
Time frame: From PACU admission to PACU discharge on the day of surgery
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Oct 2026.
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Remimazolam in people with Sedation During Lower Extremity Surgery Under Spinal Anesthesia, run by Seoul National University Hospital at 1 site in South Korea.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 13 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in South Korea. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Between-Patient Coefficient of Variation in Model-Predicted Effect-Site Concentration Associated With Target Sedation (time frame: During intraoperative remimazolam sedation, from loading through infusion cessation on the day of surgery). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Oct 2026; AzTrials last refreshed its copy on 26 Oct 2026.