Canine Anesthesia Flashcards
Why do dogs (and cats) have a higher mortality rate during anesthesia compared to humans
Anesthesia causes cardiorespiratory depression which is the main cause of death, hence it’s important to monitor the patient during anesthesia to reduce the risk of death
Before putting a dog under anesthesia what is some things you would want to consider that could influence you anesthetic plans
Look at their history: what drugs are they on, do they have systemic disease, have a history of previous anesthetic complications, have a history of blood transfusions
What is their signalment: age, sex, breed
What is their temperament
What a some medications of concern for anesthetic procedure and the brief description of why it is concerning
Diuretics - can cause hypovolumeia and electrolyte changes
ACE inhibitors/ Ca channel block/ beta block - cause hypotension
Anti-epileptic agents - cause extra sedation and are hepatic enzyme inducer
Serotonin drugs - risk of serotonin syndrome (more of a problem when the ingest human prescription)
NSAIDS/Steroids
What should you do if a patient is coming in for an anesthetic procedure and are presenting with a cough, exercise intolerance, or syncope
*realize they are having signs of systemic disease that is affecting the cardiorespiratory system and are at a greater risk of anesthetic death
*postpone procedure if possible and try to stabilize the patient
Do dogs have naturally occurring antibodies against red blood cell antigens
No they need to have been exposed to the antigens and for days to go before they produced. Hence they normally do not have severe reactions to their first blood transfusion
What is the universal blood donor for dogs
It’s best to use DEA 1.1 Negative blood
What is a breed specific concern of Northern breeds (Huskies, Malamutes, Samoyed, Inuit)
They are resistant to sedative effects of opioids and acepromazine
Opioids can cause excitement during recovery
Best to give opioids with alpha-2 (dexmedetomidine)
What is a breed specific concern of Herding breeds (Australian shepherds, collies,)
Have MDR-1 gene mutation so they have higher level of drugs entering the brain so more susceptible to CNS depression from acepromazine and opioids
Avoid use of Ace and use low doses of opioids
What is a breed specific concern of brachycephalic breeds (bulldogs, pugs, and Boston terriers)
They can have BOAS (brachycephalic obstructive airway syndrome) in which they are at high risk of hypo ventilation/hypoxemia and aspiration pneumonia which puts them at high risk of death
What is the best anesthetic protocol for dogs with BOAS (premed, induction, maintenance, recovery)
-premed - Antiemetic (maropitant), + steroid (decrease airway swelling) +/- anticholinergics +/- opioids (methadone/butorphanol). Make sure to minimize stress and start monitoring right away
-induction - pre-oxygenate, rapid IV induction (propofol/alfaxalone). Intubate with smaller ET tube
-maintenance - with quickly reversible drugs and possible mechanical ventilation
-recovery - monitor SpO2, late extubation, adequate analgesia
What is a breed specific concern of sighthounds
Avoid thiobarbiturates due to prolonged recovery
What is a breed specific concern of greyhounds
Susceptible to anesthetic induced hyperkalemia and excessive post op bleeding
Monitor ECG, K levels, and give antifibrinolytic perioperative
What is a breed specific concern of boxers
Possible sensitivity to acepromazine and concern for collapse
What is a breed specific concern of small breeds (yorkies, Pomeranians, poodles, chihuahuas, etc)
They are at risk of tracheal collapse (will present with dyspnea, exercise intolerance, goose-honk cough, stridor)
Recommended to avoid excitement (sedation), avoid coughing (butorphanol for its antitissive effect), have longer ET tube to reach the carina
What are some premeditation drugs in dogs
-Anticholinergics (Atropine and glycopyrrolate) - useful in BOAS patients, dogs undergoing ophthalmic s/ GI endoscopy, don’t use with alpha-2, NOT A NORMALLY USED PREMED (treats low HR AND HYPOTENSION)
-Benzodiazepines - sedation for young, sick, old patients with minimal cardiovascular and respiratory effects
-Acepromazine- mild/moderate sedation (can cause hypotension and hypothermia)
-Dexmedetomidine - marked sedation at high doses (can cause hypertension, reflex bradycardia, decreased cardiac output)
-Opioids- analgesic (methadone,fentanyl, and butorphanol more common due to least likely to cause vomiting)
