Veterinary Medicine - Anesthesiology Flashcards
Capnography - Rebreathing CO2 - Possible Causes
Tachypnea, Low oxygen flow relative to respiratory rate, Soda lime exhaustion, Stuck one-way valve, Patient too small for rebreathing circuit, Increased resistance in circuit
Capnography - Rebreathing CO2 - Management
Increase flow rate until inspiratory CO2 goes down to zero, Check inspiratory valves, Check soda lime color, Check source of resistance, Ventilate
Capnography - High ETCO2 - Possible Causes
Deep-plane anesthesia, Lung disease, Atelectasis, Obesity, Body position, Induction apnea
Capnography - High ETCO2 - Management
Decrease anesthesia gas, Mechanical ventilation
Capnography - Tachypnea - Possible Causes
Low plane anesthesia, Pain, Hyperthermia
Capnography - Tachypnea - Management
Increase anesthesia, Analgesia, Cooling, Ventilate
Capnography - Leak in the circuit - How does it look?
Slowly tapering of ETCO2 after normal initial expiration and plateau
Capnography - Leak in the System - Management
Inflate ET cuff, Replace circuit
Capnography - “Shark Fins” - Possible Causes (2)
Partial obstruction of the circuit, Bronchoconstriction
Capnography - “Shark Fins” - Management
Clear obstruction, Administer Bronchodilators
Capnography - “Additional Peaks” - Cause
Flow rate is lower than required - Patient is breathing in his own
Capnography - “Additional Peaks” - Management
Increase ventilation, Administer OpiatesKetamine to cause respiratory depression + increase ventilation
You’re experiencing Capnography abnormalities - Describe the management algorithm
1) Check Patient (Pulse / Breathing / Reflexes) 2) Check O2 Flow + Ventilate 3) Check Soda Lime Valves Circuit 4) Check Capnograph
Oscillometric Pressure Devices - Best placed on which artery?
Coccygeal A.
Doppler Pressure Devices - Best placed on which artery?
Metatarsal A.
Doppler Pressure Devices - Measures…?
Systolic Arterial Pressure (SAP)
Oscillometric Pressure Devices - Measures…?
Mean Arterial Pressure (Measured directly). *SAP (Calculated). *DAP (Calculated)
Oscillometric Pressure Devices - Originally created for human patients with human sized arteries - Therefore the use of them is less recommended in which animals?
Cats, Small breed dogs
Invasive blood pressure measurement - Contraindications
Thrombocytopenia, Thrombocytopathy, Decrease in clotting factors
Invasive blood pressure measurement - Indications
Sepsis, GDV, Suspected Expected reperfusion injury , Active Expected hemorrhage , Cardiac failure, Shock of any kind, Unstable BP of any kind
a2 Agonists - What are our 2 reversal drugs and when to use them?
1) Vasoconstriction (Peripheral effect) -> Reflex bradycardia. 2) Vasodilatation (Central Effect) + Bradycardia
Hypertension - Causes
Situational (e.g. Stress, Excitement). Secondary: -Renal disease (e.g. AKI, CKD). -Endocrinopathies (e.g. Cushing’s disease, Hyperaldosteronism, Diabetes Mellitus, Hyperthyroidism, Hyperestrogenism). -Pheochromocytoma. -2nd to high Intracranial pressure
Screening for Hypertension - What is the best organ to assess?
Retina
Anesthesia in Brachycephalic Syndrome - Sedation / Analgesia / Pre Induction / Induction / Post-anesthesia important notes
Sedation - Midazolam (Preferably no hard sedatives). Analgesia - Light opiates (due to GI signs). Pre Induction - O2 for a few minutes. Induction - Propofol. Post Op: Late extubation | O2 for a couple of hours Cooling Steroids if airway inflammation is present
Anesthesia in (Chronic) Renal Disease - What is the most contraindicated induction/anesthesia drug? Why?
Ketamine. It’s metabolite (Nore-ketamine) can’t be excreted through the kidneys - thus making the effect longer
Anesthesia in (Chronic) Renal Disease - Sedation / Induction
Sedation - Midazolam Induction - Propofol / Alfaxolone
Anesthesia in (Chronic) Renal Disease - Why is hypotension dangerous when anesthetizing kidney-disease patients? How to treat if it does happen?
The kidneys already aren’t fuctioning properly and GFR is lowered, and in addition to that - Perfusion is furthered lowered - Worsening GFR. Treat aggressively with everything you have! Don’t let the kidneys suffer any more! Options: 1) Ephedrine (alpha & Beta Agonist) 2) Dobutamine 3) Norepinephrine / Dopamine
Anesthesia in liver failure - Sedation / Analgesia / Pre Induction / Induction / Anesthetic Drug
Sedation - Midazolam (or any other reversible sedative). Analgesia - Opioids. Pre induction - Correct hypoalbuminemia, hypoglycemia. Induction - Propofol. Anesthesia - Any gas anesthesia
Anesthesia in Neonates - Cardiac output is mostly determined by?
Heart Rate
Anesthesia in Neonates - Anesthesia-wise, Neonates should be treated like they have — & — failure
Liver and kidney failure
Anesthesia in Neonates - Contraindicative sedatives
Acepromazine (Causes Hypotension), Medetomidine (Causes Bradycardia)
Anesthesia in Neonates - Induction drug that is contraindicated and why
Ketamine. Same as with liver failure - Can’t excrete the metabolite
Anesthesia in Neonates - Sedation / Analgesia / Pre Induction / Induction / Anesthetic Drug
Sedation - Midazolam. Analgesia - Opioids. Induction - Propofol / Alfaxolone. Anesthesia - Any gas anesthesia
Anesthesia in liver failure - Sedation is preferred with Diazepam / Midazolam
Midazolam
C-Section and Anesthesia - A lot of drugs are contraindicated because most drugs will also affect the puppies. What is the recommended protocol for performing a C-Section?
Analgesia - Opioids ONLY AFTER PUPPIES ARE OUT! Induction - Alfaxolone > Propofol. Maintenance gas - Desflurane . No Sedation / Analgesia if puppies are still inside!
Anesthesia and Heart Failure - Contraindicated drugs
Acepromazine (Hypotension / Can’t be reversed). Medetomidine (Hypotension / Bradycardia). Atropine (Not recommended)
Anesthesia and Heart Failure - Sedation / Analgesia / Induction / Anesthetic Drug
Sedation - Midazolam. Analgesia - Opioids. Induction - Alfaxolone >> Propofol. Anesthesia - Any gas Anesthesia
What NSAIDs can be used in Cats with a low risk for causing AKI?
Robenacoxib
What NSAID is recommended to be administered only once in Cats?
Meloxicam
What NSAID can be given to puppies 6 weeks or older (As opposed to other NSAIDs that are only from 6 months <)
Carprofen
NSAID Administration - Contraindications
Renal Failure, Liver Failure, Heart Failure, Dehydration / Hypotension / Shock / Hemorrhage , GI Disease, Concurrent GC administration, Very young puppies, Coagulopathies, Spinal injuries
Anesthesia - What are important monitoring needed during the anesthesia?
BP (Ocillometry / Doppler), Pulse Oximetry, etCO2, ECG, Temp, Plane of anesthesia (e.g. Palpebral / Location of pupil)
What is the “R on T” Phenomenon on EKG?
Fusion of the two due to VPCs. Can indicate incoming Ventricular Tachycardia / Fibrillation
Why are multi-focal (Heterogenous morphology) VPCs are more dangerous and require treatment as opposed to a single-origin VPCs (Single morphology)? What is the treatment?
Indicates incoming Ventricular Tachycardia / Fibrillation. Lidocaine
How and when do you treat a patient who starts having AV-Block under anesthesia?
1st Degree - not uncommon under anesthesia. Not necessarily requires treatment. 2nd Degree - treat with Atropine / Glycopyrrolate. 3rd Degree - requires a pacemaker!
Why does anti-cholinergic drug (i.e. Atropine) can sometimes cause (instead of curing) AV-Blocks and worsening of bradycardia?
Usually happens with under-dosing of Atropine. It binds to the pre-synaptic receptor causing a negative feedback loop on the inhibition -> Increasing the release of ACh
What are 2 common Vasopressors used in an emergency setting / anesthesia complications?
Dopamine, Norepinephrine
What are the 2 best pre-vet visit anxiolytic drugs for dogs and cats?
Gabapentin - Cats, Trazodone - Dogs
In-hospital sedation in cats - What would you choose for light / moderate / strong sedation?
-Butorphanol -Acepromazine -Dexmedetomidine. + Alfaxolone (Recommended), +/-Midazolam
What sedative is contraindicated in animals with heart problems?
Medetomidine
Anesthesia in cardiovascular patients - What are our choices in terms of induction drugs?
1) Alfaxolone 2) Propofol 3) Etomidate
Anesthesia in Cardiovascular Patients - What Drug is Absolutely Contraindicated in Cats with HCM
Ketamine
What drug family is highly associated with high risk of causing reflux during anesthesia? of the family - which is the Least risky option?
Opiates . Demerol (Safest)
What are the Risk Factors for Reflux during Anesthesia?
Orthopedic surgery, Recumbency: Dorsal, Bigger Breeds >> Smaller Breeds, Long anesthesia, Drugs: Opioids , Older Dogs, Pregnancy: 2nd/3rd Trimester
Reflux due to anesthesia - prevention
8-12 hours fasting prior to surgery, Metoclopramide CRI, Omeprazole
Reflux due to Anesthesia - If Happened Already - What to do?
Warm water lavage until content clears +/- Bicarbonate
What is the Ultimate Risk of Reflux During Anesthesia?
esophagitis —-> STRICTURE
