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Aging reduces the reliability of epidural epinephrine test doses
J P Guinard1, M F Mulroy, R L Carpenter
1Service d'Anesthésiologie, Clinique de Genolier, Switzerland.
Regional Anesthesia
|May 1, 1995
Summary
Aging reduces the heart rate response to epinephrine test doses. A 10 microgram dose is sufficient for younger patients, but older individuals may require higher doses due to decreased beta-adrenergic responsiveness.
Area of Science:
- Anesthesiology
- Pharmacology
- Gerontology
Background:
- Beta-adrenergic responsiveness significantly decreases with age.
- Previous studies showed epinephrine test doses reliably increase heart rate in young individuals.
- Aging may impact the effectiveness of epinephrine test doses.
Purpose of the Study:
- To determine if aging reduces the magnitude of heart rate increase after intravascular epinephrine injection.
- To assess the impact of age on epinephrine's beta-adrenergic effects.
- To evaluate the reliability of epinephrine test doses in different age groups.
Main Methods:
- A randomized, double-blind study involving 30 surgical patients aged 21-81.
- Patients received intravascular injections of lidocaine with or without epinephrine (10 or 15 micrograms).
- Heart rate and systolic blood pressure were monitored throughout the procedure.
Main Results:
- Increasing age correlated with smaller heart rate increases following epinephrine injection.
- The reduction in heart rate increase was significant for 10 micrograms of epinephrine (P = .006).
- Heart rate increases were larger in patients under 40, with no significant change in systolic blood pressure due to aging.
Conclusions:
- Aging is associated with diminished heart rate response to intravenous epinephrine.
- A 10 microgram epinephrine test dose is adequate for detecting intravascular injections in patients under 40.
- Higher epinephrine doses (15 micrograms) may be less reliable in older patients due to reduced beta-adrenergic responsiveness.