Effects of preanesthetic medication midazolam-sufentail or midazolam-alfentanil on induction dose of propofol and on cardiopulmonary changes in dogs

Abstract

Preanesthetic medications smooth the induction of anesthesia, and reduce the stress of animals. It is also valuable for reducing the required dose of injectable anesthetic needed for induction of anesthesia and may result in fewer adverse effects or effects of lesser severity.Propofol is a short-acting hypnotic that belongs to the alkyphenol family. It is commonly used to induction of anesthesia in dogs, and produces unconsciousness in a rapid, smooth and safe fashion in health animals. However it is not an analgesic drug, being necessary to associate this drug with others that produce analgesia.Sufentanil and alfentanil are potent synthetic opioid agonist, have high affinity at the receptor OP3 (µ), and are related to phenylpiperidine derivates. These drugs are short-acting, and are used on induction of anesthesia and during intraoperative procedure.Midazolam is a benzodiazepine derivative considered safe due to cardiovascular stability after administration. This drug has hypnotic action, and increases the effects of anesthetic and opioids concurrently used during the maintenance of anesthesia.Therefore, there is little available information regarding the effects of the administration of midazolam associated to these potent opioids as preanesthetic medications in dogs submitted to induction of anesthesia with propofol. Then, the purpose of the study is to compare the cardiopulmonary effects of midazolam associated to sufentanil or alfentanil, as preanesthetic medications in dogs induced to anesthesia with propofol, as well as to verify the influence of drugs on the induction dose of propofol.