Anesthesia, Spinal, Bradycardia, Dexmedetomidine
Conditions
Brief summary
Spinal anesthesia is widely used for lower extremity surgery, and sedation is often required during surgery. For sedation, propofol, midazolam and dexmedetomidine are frequently used. Dexmedetomidine is a highly selective alpha 2 receptor agonist, and has sedating and analgesic effect. Compared with propofol and midazolam, it has little or no respiratory inhibition and hemodynamically stable. It also has the effect of reducing delirium in the elderly. Dexmedetomidine has also been reported to prolong the duration of sensory and motor blockade effects of spinal anesthesia. However, several studies have reported that administration of dexmedetomidine in spinal anesthesia increases the incidence of bradycardia. In a study of healthy young adults, concurrent administration of atropine with dexmedetomidine in spinal anesthesia significantly reduced the frequency of bradycardia requiring treatment. However, in elderly patients, it is often reported that there is little response to atropine in bradycardia, and ephedrine is more effective in treating bradycardia than atropine in the elderly. The investigators therefore compared ephedrine and atropine as pretreatment to reduce the incidence of bradycardia when using dexmedetomidine as a sedative in elderly patients undergoing spinal anesthesia.
Interventions
DRUGnormal saline
intravenous normal saline pretreatment at the onset of dexmedetomidine infusion
DRUGatropine 0.5mg
intravenous atropine 0.5mg pretreatment at the onset of dexmedetomidine infusion
DRUGephedrine 8mg
intravenous ephedrine 8mg pretreatment at the onset of dexmedetomidine infusion
Sponsors
Ajou University School of Medicine
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
65 Years to 100 Years
Healthy volunteers
No
Inclusion criteria
* American Society of Anesthesiologists (ASA) classification I-II * Undergoing orthopedic surgery under spinal anesthesia
Exclusion criteria
* Contraindication for spinal anesthesia * Atrial fibrillation, atrial flutter * Cardiac valve disease * Neurologic disease * initial systolic blood pressure in operating room \> 160mmHg
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| The incidence of intervention for bradycardia | for 1 hour after spinal anesthesia | The number of treatment for bradycardia which is defined as heart rate under 50 beats per minute |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| The incidence of intervention for hypotension | for 1 hour after spinal anesthesia | The number of treatment for hypotension which is defined as systolic blood pressure in under 100 mmHg or systolic blood pressure under the 30% of baseline systolic blood pressure |
| Systolic/ mean/ diastolic blood pressure | for 1 hour after spinal anesthesia | Systolic/ mean/ diastolic blood pressure |
Countries
South Korea
Outcome results
None listed