The effect of age on rate of functional recovery after intracarotid amobarbital injection

Purpose: The duration of the drug effect during the intracarotid amobarbital procedure (IAP) is an important factor when considering the prioritization of behavioral testing during the IAP. Previous studies of thiopental, a barbiturate similar to sodium amobarbital, found that age and gender significantly affect the dose required to induce anesthesia, such that younger patients require higher dosage. Methods: A total of 55 patients who underwent the IAP procedure at Johns Hopkins Hospital were included in the study (110 hemispheric injections). The patient group included 30 female and 25 male patients, ranging in age from 11 to 50 years. To determine if a higher dose of sodium amobarbital was needed for younger patients during the IAP, we analyzed the time to return to preinjection EEG baseline status and time to return to 5/5 strength as a function of patient age and gender. Results: We found that younger patients (11-20 years old) returned to preinjection baseline EEG status and full (5/5) strength faster than older patients. No gender difference was found. Conclusions: The sodium amobarbital effect during IAP dissipates faster in young patients. Consideration of this difference in rate of recovery in 11-to 20-year-old patients has important clinical implications in terms of prioritizing behavioral testing.