Balanced Anesthesia Flashcards
what are the desired effects of anesthesia
- unconsciousness
- amnesia
- immobility and muscle relaxation
- analgesia
- autonomic stability
what are the desired effects are produced by inhalants
amnesia
immobility & muscle relaxation
+/- unconsciousness
what are the CV effects of inhalants
vasodilation
hypotension
what are the respiratory effects of inhalants
decreased response to CO2
decreased respiratory rate
what are additional characteristics of inhalants
hyperalgesia
narrow therapeutic margins (compared to IV)
global warming + greenhouse gases
what is balanced anesthesia
using multiple drugs to achieve anesthesia so that each drug is used at a lower dose than if used alone
results in less adverse effects
PIVA
partial intravenous anesthesia
combining inhalant + injectable anesthetics
what are the goals of balanced anesthesia
- approach an “ideal drug” by combining drugs that have different main effects
- decrease inhalant requirement (to decrease CV and respiratory depression)
main effect of hypnotics
unconsciousness
main effect of benzodiazepines
amnesia
main effect of NM blocking agents
muscle relaxation
main effects of opioids
analgesia + autonomic stability
what qualities are ideal for an IV drug used in balanced anesthesia
- reduces inhalant requirement
- improves CO
- improves BP
- improves ventilation
- causes no to minimal CV depression
- causes no to minimal respiratory depression
what injectable drugs are used with inhalants to achieve balanced anesthesia
- local anesthetics
- nitrous oxide
- opioids
- ketamine
- IV lidocaine
- alpha-2 agonists
effects of opioids as balanced anesthetic
- reduces MAC (dogs > cats)
- minimal CV depression
- respiratory depression (dogs > cats)
butorphanol is MORE effective in cats than full mu agonists
effects of ketamine as balanced anesthetic
- reduces MAC
- improves CV function (dogs > cats)
- minimal respiratory depression
- prevents hypothermia
effects of IV lidocaine as balanced anesthetic
- reduce MAC
- CV depression (cats only; no effect in dogs)
- antiarrhythmic
effect of dexmedetomidine as balanced anesthetic
- reduces MAC
- CV depression (cats > dogs)
- analgesia + blunts autonomic response
what is the ideal balanced anesthesia in dogs
large dose opioids
ex. inhalant + fentanyl CRI
what is the ideal balanced anesthesia in cats
none - possibly ketamine but can have a dysphoric wake up
