Frailty, Anesthesia Induction
Conditions
Keywords
Remimazolam Tosilate, Frailty, Anesthesia Induction, Median Effective Dose (ED50), Dixon Up-and-Down Method, Respiratory Volume Monitor (RVM)
Brief summary
This study aimed to determine the median effective dose (ED50) of remimazolam for loss of consciousness (LOC) in elderly and frail elderly patients using the Dixon up-and-down method, while utilizing a novel Respiratory Volume Monitor (RVM) to detect subclinical respiratory depression.
Detailed description
The physiological decline associated with frailty in elderly patients presents significant challenges for anesthesia induction. Remimazolam tosilate, an ultra-short-acting benzodiazepine, offers a promising safety profile, yet its optimal dosing in frail populations remains undefined. This prospective, up-and-down sequential allocation trial was conducted at the Second Hospital of Hebei Medical University. 58 patients aged ≥65 years undergoing elective surgery were stratified into two groups: an Elderly Group (Clinical Frailty Scale \[CFS\] \< 5) and a Frail Elderly Group (CFS ≥ 5). The initial remimazolam induction dose was set at 0.15 mg/kg for the elderly group and 0.13 mg/kg for the frail group, with dose adjustments based on the previous patient's response. A non-invasive RVM was employed to continuously monitor Tidal Volume (VT) and detect early hypoventilation.
Interventions
The initial induction dose was set at 0.15 mg/kg administered as a single intravenous bolus over 30 seconds. The dose adjustment gradient for consecutive patients was 0.02 mg/kg based on the Dixon up-and-down method.
Sponsors
The First Hospital of Hebei Medical University
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
65 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Aged ≥65 years; * Scheduled for elective surgery under general anesthesia with endotracheal intubation; * American Society of Anesthesiologists (ASA) physical status II or III; * Body Mass Index (BMI) between 18 and 30 kg/m².
Exclusion criteria
* Known allergy to benzodiazepines; * History of severe respiratory or cardiovascular disease (e.g., acute heart failure, severe COPD); * Long-term use of sedatives, analgesics, or alcohol abuse; * Known neuromuscular disorders (e.g., myasthenia gravis); * Inability to communicate for sedation assessment.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Sedation Success (Loss of Consciousness) | up to 2 minutes | Defined as the achievement of Loss of Consciousness (LOC) confirmed by loss of eyelash reflex, no response to verbal commands, Ramsay Sedation Score ≥ 5, and MOAA/S score \< 1. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Median Effective Dose (ED50) of Remimazolam | Perioperative/Periprocedural | The ED50 calculated via probit analysis based on the Dixon up-and-down sequential allocation method. |
| Changes in Tidal Volume (VT) | Baseline, 30 seconds, 60 seconds, 90 seconds, and up to 120 seconds post-administration | Continuous assessment of spontaneous Tidal Volume (VT) utilizing a non-invasive Respiratory Volume Monitor (RVM) to evaluate subclinical respiratory depression. |
| Mean Arterial Pressure (MAP) | Baseline and up to 2 minutes post-administration | Changes in Mean Arterial Pressure (MAP) during the induction period, measured in mmHg. |
| Heart Rate (HR) | Baseline and up to 2 minutes post-administration | Changes in Heart Rate (HR) during the induction period, measured in beats per minute. |
Countries
China
Outcome results
None listed