Anesthesia reboot: Erase these myths and misconceptions

Aug 24, 2014

Are you up-to-date on the best anesthetic practices to use in your patients? You may be holding onto important misconceptions, including the following:

• Most opioids can cause hyperthermia in cats. A recent study has shown a strong association of hyperthermia with hydromorphone, especially when ketamine is used concurrently.1 Dr. Weil’s solution: Administer a microdose of medetomidine (1 µg/kg) postoperatively in cats that have received hydromorphone and ketamine.

• Misconceptions abound in terms of breed “sensitivities” to anesthetic drugs. The only documented sensitivity is associated with greyhounds and barbiturates. Their livers’ cannot to process drugs in the same manner as other dogs. However, since barbiturates are rarely used anymore, this problem is almost obsolete.

• Excessive bradycardia from dexmedetomidine should be handled by reversing the drug with atipamezole, not by using an anticholinergic such as atropine or glycopyrrolate. Partial reversal can be done by using a half dose of atipamezole.

• If you are giving injectable combinations of anesthetic drugs, keep in mind that hypoxemia and hypercapnia are likely. Thus, be sure to use an oxygen mask in these patients.

• Stop using the old-school 10 ml/kg/hr anesthetic fluid rate as a guide. The American Animal Hospital Association (AAHA) has new initial fluid rate recommendations: 5 mg/ kg/hr in dogs and 3 mg/kg/hr in cats. Get all the details from AAHA’s fluid therapy guidelines here.



1. Posner LP, Gleed RD, Erb HN, et al. Post-anesthetic hyperthermia in cats. Vet Anaesth Analg 2007;34(1):40-47.