Anesthesia Info

How does anesthesia affect cardiac measurements and exam interpretation?

Drugs that are frequently used for immobilization of the great apes include ketamine, with or without adjunct tranquilizer (such as midazolam or other benzodiazepine); telazol™, a proprietary mixture of tiletamine and zolazepam (also referred to Zoletil in other countries); and medetomidine, in combination with either telazol™ or ketamine. All of drugs / drug combinations generally provide safe and effective immobilizations, however alpha-2 agonists (e.g. medetomidine) may present a significant risk to apes that are predisposed to or already have cardiovascular disease.

If you plan on performing a cardiac assessment under anesthesia and would like to submit the exam to the GAHP for review and inclusion in the database, we ask that you consider not using alpha-2 agonists such as medetomidine. Exam measurements obtained under alpha 2-agonists will not provide a truly diagnostic evaluation and may result in inaccurate diagnoses. While we are currently continuing to accept exam submissions with alpha-2 agonists, our cardiac advisory team will not be able to provide an official report in these cases.

Our GAHP anesthesia advisor, Dr. Ben Brainard, has created a review of anesthetic effects on cardiac ultrasound evaluations with additional references to consider (Anesthetic Concerns for the Cardiac Examination of the Great Apes – Benjamin Brainard). If you have any questions about anesthesia considerations for a cardiac exam, please contact us at

Please also refer to Performing Cardiac Ultrasound Exams.