September 21, 2011
Study Showed Stimulant Medication Helped ‘Wake Up’ Animals From General Anesthesia
A study published in October’s issue of Anesthesiology found that methylphenidate, a drug used in patients to treat attention deficit hyperactivity disorder, when given to rats while under general anesthesia caused them to awaken faster from anesthesia when compared to rats that didn’t receive the stimulant.
“We are only beginning to learn about which pathways in the brain are important for emerging from general anesthesia,” said lead study investigator Ken Solt, M.D. “Our study suggests that methylphenidate may wake up animals from general anesthesia by activating dopamine- and norepinephrine-mediated arousal pathways.”
About the Study
Investigators used adult rats to test the effect of methylphenidate on time to emergence from general anesthesia. They also performed experiments to test the effects of methylphenidate on sedation and respiratory depression by general anesthesia. Electroencephalogram (EEG) recordings showed that the brain developed an arousal pattern, confirming the animals “woke up” after being given methylphenidate. Measurements of respiratory rate, as well as oxygen and carbon dioxide levels within the blood, confirmed that methylphenidate also reversed respiratory depression in the animals.
Investigators found that administering methylphenidate lessened the time from end of anesthesia to awakening by three fold.
This finding offers a new perspective for scientists on the process of emergence from anesthesia. Currently, physicians wait for the anesthetics to wear off. In a few cases, antidotes to reverse drugs like muscle relaxants and narcotic analgesics can be administered. There are no receptor antagonists to reverse sedation and respiratory depression from general anesthesia.
“In this study, methylphenidate helped to overcome the effects of the general anesthetic by activating brain arousal centers,” said Dr. Solt. “More research needs to be done to confirm the value of the use of methylphenidate in anesthesia emergence.”