ANSWER:

Muscular relaxation 

analgesia 

Unconsciousness 

ANSWER:

1. Preanesthetic evaluation 

2. Premedication period 

3. Induction to anesthesia

4. Maintenance

5. Recovery 

ANSWER:

Minimal risk - Normal, healthy patient 

IE.  young healthy animal with no organ disease 

ANSWER:

Slight risk - Mild systemic disease 

IE.  skin tumor, stable fracture

ANSWER:

Moderate risk - severe but not incapacitating disease 

IE. fever, dehydration, compensated renal or cardiac disease. 

ANSWER:

High risk - incapacitating systemic disease 

IE. decompensated renal or cardiac disease, septicemia

ANSWER:

Grave risk - Moribund patient, not expected to live

IE. Severe trauma, terminal malignancy

The ideal general anesthetic agent would not require metabolism for termination of action or elimination.

True or False?

ANSWER:

TRUE 

An ideal anesthetic agent would not be toxic, and toxic side effects can be a consequence of drug metabolism. 

Ideal anesthetics would also be rapidly eliminated and reversible.  

The ideal general anesthetic drug would require an additional muscle relaxant drug.

True or False?

ANSWER:

FALSE 

An ideal anesthetic would provide analgesia and muscle relaxation, however, this is most often not possible without the use of multiple drugs.  

The ideal general anesthetic agent could be injected intramuscularly because it would not be irritating to use. 

True or False?

ANSWER: 

TRUE 

An ideal anesthetic would be non irritating and easy to administer.  

The ideal general anesthetic agent will require an expensive, agent-specific vaporizer. 

True or False?

ANSWER:

FALSE

An ideal anesthetic agent would be inexpensive and easy to administer. 

The ideal anesthetic agent would be non-toxic to humans and animals.

True or False?

ANSWER:

TRUE 

An ideal anesthetic would be non toxic to patients or environment. 

How would you describe the action of the anesthetic drug:

GLYCOPYRROLATE?

ANSWER: 

Glycopyrrolate is an anticholinergic drug.

These drugs are parasympatholytic, and competitively antagonize acetylcholine at muscarinic receptors.  

These drugs prevent bradycardia and excessive secretions.

(blocks signals from parasympathetic nerves) 

How would you describe the action of the anesthetic drug:

ACEPROMAZINE?

ANSWER: 

Acepromazine is a phenothiazine tranquilizer. 

These tranquilizers depress alterness and have potent adrenergic-blocking properties.  These sedatives are mentally calming, reduce locomotor activity, and put them into a sleep-like state. 

Animals can still be aroused by stimuli. 

How would you describe the action of the anesthetic drug:

MIDAZOLAM?

ANSWER:

Midazolam is a benzodiazapine anxiolytic. 

This drug provides amnesia and muscle relaxation - causes sedation but can still be aroused by stimuli.  

Has been described as an acceptable drug in swine. 

How would you describe the action of the anesthetic drug:

KETAMINE?

ANSWER: Ketamine is a dissociative hypnotic.

Can be used at low dose, one of the few drugs that can be used intramuscularly.  Creates good somatic analgesia, poor visceral. INCREASES sympathetic tone (increased HR, BP, CO), muscular tone, intraocular pressure, hypersalivation > possible seizures.

The major inhibition is at NMDA. 

It is a DEA schedule III controlled substance. 

How would you describe the action of the anesthetic drug:

DEXMEDETOMIDINE?

ANSWER: Dexmedetomidine is a alpha-2 agonist sedative

This large group of drugs act on alpha-2 receptors causing CNS depression, analgesia and muscle relaxation.

Causes MAC reduction. 

How would you describe the action of the anesthetic drug:

FENTANYL?

ANSWER: fentanyl is an opoid mu analgesic. 

Bind to opoiate receptors (MOP, OP3) in the brain and spinal cord, resulting in sedation and analgesia. 

High analgesic potency (100X more than morphine) - so administered in low doses. 

Rapid onset, short action duration. 

ANSWER: Atipamezole is an alpha-2 antagonist. 

Can be used to reverse the effects of Alpha-agonists.

How would you describe the action of the anesthetic drug:

NALTREXONE?

ANSWER: Naltrexone is an opoid antagonist. 

Which of the following drugs used in anesthetic protocols will cause hypotension due to peripheral alpha-1 receptor blockade?

A) Diazapam 

B) Acepromazine 

C) Xylazine

D) Atropine 

E) Morphine 

ANSWER:  B) Acepromazine 

Potent adrenergic blocking properties by binding to alpha-1 receptors preventing norepinephrine from initiating vasoconstriction. 

Which of the following is true concerning Propofol?

A) A yellow opaque emulsion that can be injected IM or IV

B) A GABA receptor antagonist

C) The vehicle used is a good media for bacterial growth if contaminated.

D) Currently controlled by the US DEA as a schedule II drug

E) Excreted primarily as an unchanged drug by kidneys 

ANSWER: C) the vehicle used is a good media for bacteria growth if contaminated. 

Propofol is a white opaque emulsion that can only be given IV. 

It is currently not controlled but will be a schedule IV drug

Undergoes rapid redistribution and is metabolized by the extra hepatic sites (GI and Lungs)

Which one of the following is false concerning Ketamine?

A) It produces good somatic analgesia 

B) It increased skeletal muscle tone

C) It only slightly depresses reflexes like palpebral and swallowing

D) Decreases cerebral blood flow and intracranial pressure

E) Increases sympathetic nervous system tone

ANSWER: D) decreases cerebral blood flow and intracranial pressure

It INCREASES cerebral blood flow, and is contraindicated in patients with head trauma or tumor. 

Ketamine produces good somatic analgesia, but poor visceral.  It causes CNS excitement, and increases sympathetic nervous tone (increases BP, HR, CO). 

Swallowing, palpebral and laryngeal reflexes only slightly depressed.  

Which of the following drugs will inhibit adrenocorticoid function for 2-3+ hours after administration?

A) Etomidate

B) Tiletamine

C) Ketamine

D) Propofol

E) Alphaxalone

ANSWER: A) Etomidate

Honestly failing to see the point in this drug, 

its expensive, short acting, and can only be used in dogs and cats...and it inhibits adrenocorticoid function...

What is the boiling point of sevoflurane ?

ANSWER: 58.5^oC

sevoflurane will be liquid at room temperature - requires a vaporizer that takes the vapor of the liquid.

* degrades desiccated CO₂ absorbant (soda lime)

ANSWER: 48.5^OC 

This inhalant anesthetic will be a liquid at room temperature - needs vaporizer to administer the vapor from the top of the gas. 

ANSWER: -89^oC

This inhalant anesthetic will be a gas at room temperature. 

What inhalant anesthetic has the lowest vapor pressure?

A) Sevoflurane

B) Isoflurane

C) Nitrous Oxide 

ANSWER: A) Sevoflurane 

Vapor pressures:

Sevoflurane = 160 mmHg

Isoflurane = 252 mmHg

Nitrous Oxide = 39,500 mmHg

What is the MAC value of Sevoflurane in Dogs?

in Cats?

in Horses? 

ANSWER: 

Dogs = 2.3%

Cats = 2.6%

Horses = 2.3% 

This is higher than Isoflurane, but lower than desflurane and Nitrous oxide

What is the MAC value of Isoflurane in Dogs?

in Cats?

in Horses?

ANSWER: 

Dogs = 1.3%

Cats = 1.6%

Horses = 1.3% 

This is the lowest of the inhalant MAC values. 

What is the MAC value of Nitrous Oxide in Dogs?

of Cats?

of Horses?

ANSWER: 

Dogs = 188-297%

Cats = 255%

Horses = 190-205%

This is by far the highest MAC of inhalant anesthetics.

Nitrous oxide is never used as a sole agent.

Which inhalant anesthetic is best described as having:

low potency, exists as gas at room temperature, produced minimal cardiopulmonary depression and diffuses into and expands closed or trapped gas spaces?

ANSWER: Nitrous Oxide 

Boiling point is -89^oC - making it gas at room temp

MAC (Minimum Alveolar Concentration that measures Potency) = 188-297%

High MAC = LOW potency 

Which inhalant anesthetic is best described as having:

a High potency, exists as liquid at room temperature, produced dose dependent cardiopulmonary depression, and has minimal metabolic breakdown in the body?

ANSWER: Isoflurane 

Potency - MAC = 1.3% (low MAC = High Potency) 

This is the highest potency inhalant anesthetic (sevoflurane is close at 2.3%) 

Boiling point = 48.^oC making it liquid at room temp

Has low metabolism (2%) and produces pulmonary depression. 

Which inhalant anesthetic is best described as having: 

Liquid at room temperature, reacts with CO₂ absorbants to produce compound A and extremely high temperatures leading to melting, and dose dependent cardiopulmonary depression?

ANSWER: Sevoflurane 

Boiling point = 58.5^oC making it a liquid at room temp

causes cardiopulmonary depression 

Reacts with CO₂ absorbants (Soda Lime) to produce Compound A and high temps that can results in melting/fire. 

Which of the following inhalant anesthetics has the lowest blood:gas partition coefficient?

A) Isoflurane 

B) Sevoflurane

C) Nitrous Oxide 

ANSWER: Nitrous Oxide 

Isoflurane = 1.41

Sevoflurane = 0.69

Nitrous Oxide = 0.42 - this will have the highest alveolar tension 

The following is true when using eye position to monitor anesthetic depth in patients:  

 a. The globe is centered at all planes of anesthesia when Ketamine is used as part of the anesthetic protocol.

 b. In dogs and cats, the globe rolls ventrally at a light plane of anesthesia.

 c. In sheep, goats, camelids, horses and cattle, the globe does not rotate at any depth of anesthesia.

 d. The eye is centered at both light and deep planes of anesthesia and is therefore useless in assessing anesthetic depth in dogs and cats. 

 e. None of the above

Answer: A 

(B)In dogs and cats, globe is central at high and low doses, ventral only at surgical plane.

(C) sheep, goats and camelids DO NOT move, but cattle moves like the cat/dog, and horses are unreliable but often are medially located.

(D) This is only true when Ketamine is used. 

Which of the following is true regarding measurement of arterial blood pressure in anesthetized patients: 

 a. A catheter placed in a peripheral artery and connected to an aneroid or transducer is a reliable way to measure indirect blood pressure.

 b. Indirect blood pressure measurement requires very expensive equipment and is not financially feasible in most veterinary patients.

 c. The accuracy of the Doppler and Oscillometric methods of blood pressure measurement is dependent on cuff size and should be 40% of the limb circumference.

 d. Complications of oscillometric blood pressure measurement may include infection, hematoma, air embolism and thrombosis.

 e. None of the above

Which of the following is NOT a consequence of hypothermia during anesthesia: 

 a. Impaired wound healing 

 b. Increased risk of surgical wound infection

  c. Impaired coagulation

  d. Decreased minimal alveolar concentration (MAC)

  e. None of the above

Which of the following is true with regard to Intermittant Positive Pressure Ventilation (IPPV) in veterinary patients: 

 a. Indications include: hypoventilation (PaCO2 > 60mmHg), patients with head trauma or brain tumors, thoracic surgery and use of neuromuscular blockers.

 b. Peek Inspiratory Pressure in large animals should be set at 10-20 cmH2O.

 c. Tidal volume is always set at 20-30mls/kg regardless of species.

 d. Never rely on End-tidal CO2 (EtCO2) to guide use of IPPV

 e. None of the above

All of the following may be causes of INCREASED EtCO2 values EXCEPT: 

 a. Exhausted soda lime

 b. Malignant Hyperthermia

 c. Faulty one way valves

 d. Hypoventilation

 e. Fresh gas flow of 250-300ml/kg/min in non-rebreathing system

What are the 5 major steps involved in the pain pathway?  

 a. Transmission, Translocation, Modulation, Projection and Proception.

 b. Transduction, Transmission, Modulation, Projection and Perception.

 c. Translocation, Transmission, Modulation, Perception and Projection.

 d. Perception, Projection, Modulation, Transmission and Translocation.

 e. None of the above

Opioid drugs such as Hydromorphone and Fentanyl form the basis of most analgesic protocols because they affect the following sites in the pain pathway: 

 a. Modulation and Perception 

 b. Transduction, Transmission and Perception

 c. Transduction, Modulation and Perception

 d. They work at all levels of the pain pathway

 e. None of the above

Answer: C

Which of the following is true regarding pain assessment in animals? 

 a. It requires observation of pain behaviors specific for the species and individual

 b. A numeric rating scale is used where patients rate their level of pain on a scale from 0-10

 c. Is based on physiologic data such as heart rate, respiratory rate and plasma cortisol levels since these are objective measures and not dependent on subjective interpretation

 d. A pre-emptive pain scoring system is an effective assessment tool because it allows you to tailor analgesic plans/protocols to individual patients

 e. All of the above

Which of the following is false regarding nociceptors and nerve fibers involved in the pain pathway: 

 a. High threshold A-delta nociceptors only respond to tissue damaging stimuli

 b. C-fiber nociceptors discharge at a slower rate than A-delta and are responsible for ‘second pain’

 c. A-beta fibers only transmit non-painful stimuli unless ‘sensitized’ by peripheral sensitization

 d. C-fiber nociceptors are all low threshold and polymodal

 e. All of the above

Answer: D

Because ALL C-fibers are high threshold and polymodal

Why should you, as a veterinarian, be concerned with treating pain in your animal patients? 

 a. Effective pain control is important for my patient’s well being

 b. The Animal Welfare Act tells me I should

 c. Veterinarians take an oath to prevent and relieve animal suffering

 d. Effective pain control decreases the negative physiologic sequelae on the cardiovascular, immune, respiratory and endocrine systems

 e. All of the above

Where does atracurium produce its muscle relaxation effect? 

 a.  Brain

 b. Spinal cord

 c. Peripheral nerve

 d. Neuromuscular junction

 e. Actin myosin interaction

Which muscle group is the least sensitive to atracurium? 

 a. Extraocular

 b. Limb

 c. Neck

 d. Abdominal

 e. Diaphragm

Which of the following drugs is(are) depolarizing muscle relaxant(s)? 

 a. Succinylcholine

 b. Atracurium

 c. Rocuronium

 d. Pancuronium

 e. b, c, and d 

Answer: A

There is only one depolarizing muscle relaxant - 

it causes persistant depolarization of the muscle, however it has NO ANALGESIA PROPERTIES

The purpose of administering glycopyrrolate along with edrophonium to reduce the effect of atracurium is? 

 a. To block the muscarinic effects of edrophonium

 b. To block the nicotinic effects of edrophonium 

 c. To block acetylcholinesterase

 d. To prevent seizures from edrophonium

 e. To compete with atracurium at its site of action

Answer: A

Endrophonium will compete with cholinesterase, and will prevent the breakdown of ACh at muscarinic receptors as well. Gylocpyrrolate is an anticholinergic that will counter those effects.

How can you monitor the effect of atracurium in an anesthetized dog? 

 a.  Pinch the toe web and watch for a withdrawal reflex

 b. Observe the respiratory effort as an indication of diaphragm activity

 c. Stimulate a peripheral sensory nerve and observe for a withdrawal reflex

 d. Stimulate a peripheral motor nerve and observe the twitch  response

 e. Monitor the position of the eye, i.e. central vs ventral rotation

Which one of the following correctly describes the mechanism of action of local anesthetic drugs (e.g. lidocaine)? 

 a.  Opens voltage gated sodium channels allowing the cation to leave the nerve

 b. Blocks potassium channels preventing repolarization of the nerve

 c. Competitively blocks the acetylcholine receptors on neuronal synapses

 d. Blocks voltage gated sodium channels preventing depolarization of nerves

 e. Binds to GABA receptors in the nerve preventing the entry of chloride ion

Answer: D

Ionized base passes through sodium channel and binds to a hydrogen ion, blocking the channel.

This blockade will prevent the nerve from depolarizing and signal is not sent.

Which one of the following drugs is an ester linked local anesthetic? 

 a.  Lidocaine

 b. Tetracaine

 c. Bupivacaine

 d. Mepivacaine

 e. Etidocaine

Answer: B

The general rule is if there is an "I" before "caine" than it is an AMIDE, since the rest fit that rule, Tetracaine is the only that does not. 

Which of the following statements correctly describes the comparison of lidocaine and bupivacaine?

 a. Lidocaine is more lipid soluble and thus more potent

 b. Bupivacaine has a more alkaline pKa and is thus more rapidly acting

 c. Lidocaine is an ester linked local anesthetic while bupivacaine is an amide

 d. Bupivacaine is more highly protein bound and is thus longer acting

 e. Lidocaine blocks small unmylelinated fibers first while bupivacaine blocks large myelinated fibers first

Answer: D

Bupivicaine has a slower onset but longer lasting effects than lidocaine. 

It is also more cardiotoxic.

Both are amides, and both will effect small unmyeliated fibers first. 

Which of the following statements is true concerning local anesthetic toxicity? 

 a.  Lidocaine has a higher toxic dose (mg/kg) than bupivacaine.

 b. Cardiovascular depression and arrhythmias are seen first

 c. Toxicity can be prevented by combining the drug with bicarbonate

 d. Intravenous injection has a higher toxic dose than subcutaneous injection

 e. Atipamezole injection will rapidly reverse toxicity

Which of the following statements is false about oxygen compressed gas cylinders? 

 a.  A full tank is pressurized to 2,000-2200 PSI

 b. The small oxygen cylinder used on portable anesthesia machines is an “E” cylinder

 c. An “H” cylinder holds approximately 6910 Liters of oxygen

 d. An oxygen tank that is ½ full has the same pressure as a full tank

 e. In the U.S. oxygen tanks are green

Answer: D

A half full tank would have half the pressure of the original. 

Which of the following statements is true about out-of-circle vaporizers?  

 a. Less popular, not used as often as in-the-circle vaporizers in veterinary medicine

 b. Are not agent specific, that is, you can put isoflurane or sevoflurane in one

 c. They are not temperature compensated so you have to make sure your surgery room stays about the same temperature all year

 d. Less expensive to purchase than in-the-circle vaporizers 

 e. Variable bypass design and produce a very accurate concentration determined by the dial setting

Answer: G

oxygen compressed gas tank

What would happen if you mistakenly put sevoflurane into an agent-specific precision isoflurane vaporizer? 

 a. It would explode immediately after you turned the vaporizer ON

 b. The first patient anesthetized would very likely die because the output would be much higher than the dial setting

 c. The vaporizer would not produce any anesthetic vapor at all and the patient would wake up

 d. The patient would be "lightly" anesthetized because the vaporizer output would be less than the dial setting 

 e. Basically, you would not notice a difference because the precision vaporizer will produce whatever the dial is set on no matter what agent is inside 

IPPV Bellows 

This is used in large animal anesthesia (ESP HORSES) 

What are true regarding considerations of Equine anesthesia?

A) Requires controlled ventilation is often needed for long anesthesic procedures.

B) For short elective procedures, fast food and water for 3-6 hours prior to procedure

C) Hypotension should be treated and prevented

D) A and B are correct only 

E) A and C are correct only

F) All of the above are correct

E) A and C only 

Food doesnt need to be removed with short procedures.

For a 1000+ lbs. horse, what would be an appropriate size endotracheal tube?

A) 15 mm ID tube 

B) 20 mm ID tube

C) 30 mm ID tube

D) 40 mm ID tube 

Answer: C) 30 mm ID tube 

Blind intubation should be preformed with the head extended.

When horses are anesthetized, you can tell they are adequately anesthetized because they will have decreased blood pressure.  

True or False?

TRUE 

Other characteristics of adequately anesthetized horses include:

Absent or wandering nystagmus

Absence of lacrimation

No response to stimuli 

When anesthetizing horses, a common problem may be the development of bradycardia.  This can be treated with anticholinergics, but what is a possible adverse effect of these drugs?

Anticholinergics will treat the bradycardia, but could also cause GI stasis which could lead to colic.

Equine hypoxia during anesthesia can be caused by a shunt, which can be treated with oxygen.

True or False?

FALSE

Shunts can be differentiated from other causes of hypoxia because they will NOT improve when more oxygen is administered 

Standing sedation + local anesthesia 

Epidural can be used for perineal procedure 

Dental, nasal, and eye procedures

Upper airway procedures

Detomidine constant rate infusion

This is a Constant Rate Infusion combination of drugs that can be used in horses after initial bous induction.

Guaifenesin + Ketamine + Xylazine

Crystalloids 

5-10 ml/kg/hr for the first hour 

2.5-5 ml/kg/hr after that 

Low fluid rates allow the application of a fluid bolus if there is an episode of hypotension.

Synthetic colloids contain large MW molecules, stay in vascular space, exert colloid oncotic pressure

Side effects:

Fluid overload

Coagulopathies

Anaphylactic reactions

Renal dysfunction

Which synthetic colloid has the shortest halflife?

Why is that?

Dextran 70 in NaCl

It has a low molecular weight that doesnt provide much oncotic pressure.

Halflife is only about 3-12 hours.

Renal dysfunction

Coagulopathies

Pulls fluid from interstitial space

venoconstriction of large veins

increased coronary/cerebeal blood flow

increased cardiac intra-cellular Ca²⁺ 

= increased inotrophy

Hypernatremia

Hypokalemia

Hemolysis 

Hemodilution

This draws fluid from interstitium into the vessels 

which pulls prevents vessels from collapsing, but also dilutes the contents of the blood.

DO₂ is essential to patient survival.

True or False?

True 

What IS DO₂ you ask?

Delivery of O₂

I felt really brain dead that I had to look that up

What is the normal pre op PCV cut off ?

Why have a cut off?

HCT of patients before surgery should be at least 20

Any lower than this and the patient will not have adequate oxygen delivery. 

Anesthesia interferes with the body's ability to compensate for decreased oxygen content by causing decreased HR and vasodilation.

Anesthesia decreases which of the following:

A) PCV 

B) TP

C) COP

D) A and B only 

E) B and C only

F) All of the above

Answer: F) all of the above

These values should be measured after induction 

BV X (desired PCV - recipient PCV) 

        ________________________

Donor PCV

Fresh frozen plasma is best utilized in albumin replacement of large dogs. 

True or False?

False

Large doses are required to increase values of albumin so it is not very efficient to use in larger dogs. 

45 ml/kg are needed to raise albumin 1 g/dl

What drugs and physiologic conditions will cause decreased heart rate, which in turn causes hypotension?

Drugs: Opoids, alpha-2 agonists

Physiologic:

hypothermia

cardiac disease

brachycephalic 

neurological disease 

pediatric patients

Anything that reduced systemic vascular resistance, HR and/or stroke volume will contribute to hypotension.

True or False?

TRUE !

Some causes are:

hypothermia

opoids, alpha-2 agonists

cardiac disease 

bradycephaly

Anesthetic drugs: inhalants, acepromazine, propofol, thiopental (decreased vascular tone)

Blood loss

Hemorrhage, dehydration, shock, sepsis

Reduce anesthetic dose 

Decrease inhalant 

supplement with opoid, nitrous

Treat bradycardia

anticholingergics 

IV fluids 

+ iontropes 

Vasopressors

What are some examples of Positive ionotropes and vasopressors?

What are they used for?

Ephedrine

Dopamine

Dobutamine

These are used to treat hypotension in anesthestized patients.

Positive inotropy = increased contractility 

alpha1 mediated vasoconstriction

(sympathomimetic)

Used to get over the initial hypotension of induction.

Also causes NE release

Works on several sites:

Low dose: acts on DA1, DA2 = vasodilation (esp renal)

Moderate dose: B1 agonist = positive inotrophy

High dose: acts on Alpha1 & 2 = vasoconstriction, increased blood pressure and myocardial work.

Beta 1 agonist = INCREASED Contractility

Used to treat hypotension

used mostly in horses 

Drugs

Increased vagal tone

Hypercapnia (too much CO₂ in the blood)

Electrolyte/ acid-base abnormalities

Cardiac Disease

Systemic Disease (GDV, Splenic mass)

PAIN

What are some underlying causes for SINUS BRADYCARDIA?

How can it be treated?

-Increased Vagal tone (opoids) 

-Alpha 2 Agonists 

-Hypothermia 

-Significant hypoxemia

-Hypothyroid, Hypoglycemia, hyperkalemia

-Cardiac Disease

Treatment: Treat underlying disease 

Anti-cholinergic (atropine, glycopyrrolate)

except with alpha 2 agonists

What are some causes of Sinus Tachycardia?

How can it be treated?

Drugs:

Ketamine, induction agents, ANTI-CHOLINERGICs

PAIN

Hypovolemia/Anemia

Hypoxia/excessive CO₂ (Hypercarbia)

Hyperthyroidism 

Treatment: 

Beta blockers 

Treat underlying cause 

2nd Degree AV Block

Causes: 

Increased vagal tone (brachycephalics, opoids)

Bradycardia

Treatment: 

Anticholinergics

Pulseless Ventricular Tachycardia

CARDIAC ARREST

Sinus Bradycardia

Causes: 

Increased vagal tone, opoids, alpha2 agonists, hypothermia, hypothyroidism, hypoglycemia, cardiac disease

Treatment:

Anti-cholinergics (except with alpha2 agonists)

Atropine, gylcopyrrolate

Sinus Tachycardia

Causes:

Drugs -Ketamine, induction agents, anti-cholinergics

Pain, hypovolemia/anemia, hypoxia, hyperthyroidism

Treatment:

Treat underlying disease process 

Beta Blockers

Ventricular Fibrillations

CARDIAC ARREST

Ventricular Premature Contractions

Causes:

Cardiac Disease, traumatic myocarditis, hypoxemia, Ischemia, electrolyte imbalance

GDV, Pancreatitis, OSA, Splenic hemangiosarc.

Drugs: Thiopental, digitalis

Treatment:

LIDOCAINE

What are some causes of hypoventilation?

Patient factors: 

Cushings, Obesity, CNS disease

ANESTHETIC DRUGS

Anesthetic drugs cause:

Decreases responsiveness of chemoreceptor to CO₂

Decreases respiratory rate 

Decreases tidal volume 

Increases PaCO₂

= HYPOVENTILATION

Decreased LES (Lower esophageal sphincter) tone

Anesthesia causes a decreased tone of the lower esophageal sphincter - this causes stomach contents (food or acid) to reflux up esophagus 

Clinically silent 

Causes: aspiration, esophageal stricture, esophagitis

What are the ways heat is lost from the body?

Conduction 

Convection 

Radiation 

Evaporation 

Temperature less than 95^oF

Hypothermia itself is defined as less than 100^oF in small animals 

Increased Viscosity

Hypercoagulability 

(remember Virchow's triad?... well thats 2 of them)

Decreased metabolism 

Prolonger recovery time 

CNS depression

Decreased immune function

increased risk of post op infection

Increased blood viscosity 

Hypercoagulability of blood 

Decreased heart conduction 

What drugs can cause hyperthermia in cats?

Hydromorphone

other opoids

Dissociatives (ketamine) 

Pharmacogenetic disorder

excess Ca²⁺ released from sarcoplasmic reticulum,

causes increased intracellular calcium.

causes muscle rigidity and acidosis

Often triggered by stress or inhalants - remove trigger

DANTROLENE - prevents Ca2+ release (expensive!)

IV fluids

Oxygen 

SWINE

Humans 

Malignant hyperthermia-LIKE syndrome in dogs and horses

Hypothermia

Hypoglycemia

Anesthetic overdose

Breed sensitivity (sight hounds, giant breeds, collies)

Glucose homeostasis 

Protein synthesis 

Drug binding 

Oncotic pressure

Coagulation factors 

Drug metabolism 

If the liver is not functioning properly, liver products will be deceased.

Hepatocyte damage.

ALT is normally stored within hepatocytes, and when these cells are damaged.  

Hepatocyte damage

Hepatocytes swell when damaged and leak enzymes that block caniculi leading to cholestatsis 

BUN 

Glucose 

Albumin 

Clotting factors

Total Bilirubin (indirect) 

Bile Acids 

Glucose imbalances cannot be determined by clinical signs, instead they should be measured intraoperatively.

True or False?

TRUE 

Clinical signs are indefinitive (CNS depression, seizures) 

and are typically masked by anesthesia

Glucose should especially be monitored in patients with potential liver damage. 

Most inhalants are only minimially metabolized by the liver. 

Propofol (extra hepatic sites of metabolism) 

Nitrous Oxide 0%

Desflurance  0% 

Isoflurane .17%

Sevflurane 3-5%

Also reversible drugs are often not metabolized by the liver

Propofol has extra-hepatic sites of metabolism. 

Locations include the lungs and GI. 

Opiod full mu agonist

Morphine, hydromorphine, fentanyl

Benzodiazepines 

Midazolam, Diazepam, flumazanil

Alpha 2 agonist 

Dexmedetomidine, xylazine, atipamazole, yohimbine

Full mu agonist opioids include Morphine, hydromorphone, fentanyl

Full reversal can be achieved with NALOXONE

Partial reversal can be achieved with BUTORPHANOL

Decreased albumin can be caused by the liver not making enough (Liver disease/failure)

Consequences:

Increased drug binding (more effective at lower dosages = less is required) 

Decreased oncotic pressure 

Hypotension

Avoid hypoxemia - pre-oxygenate

AVOID INCREASING Cerebral Blood Flow (CBF)

Maintain MAP

Avoid ketamine

use propofol, low dose inhalant

Keep normal PaCO_{2 -} Compensation with IPPV

Maintain CO 

Avoid Fluid overload

Avoid Bradycardia/tachycardia

Avoid Hypo- or hypertension

Avoid increased myocardial work and O₂ consupmption

Avoid drugs that effect the heart 

MAINTAIN GOOD OXYGEN - preoxygenate

Use "Balanced Anesthesia" approach

Low dose acepromazine - decreases stress

Decrease use of anti-cholinergics

Decrease IV fluid rate

Tachycardia

"Gallop" murmur rhythm 

Hypertension 

Hyperthyroidism 

Renal failure 

Stenotic nare, elongated soft palate, excessive pharyngeal tissue, everted laryngeal saccules, and hypoplastic trachea

are physical properties of what genetic syndrome?

BRACHYCEPHALIC SYNDROME

Results in upper airway obstruction 

What are some considerations for premedication and induction of brachycephalics?

Give low dose acepromazine to relieve stress of upper airway obstruction.

Give anticholinergics to relieve high vagal tone from upper airway obstruction.

Pre oxygenate

Use propofol for quick recovery - minimal side effects  

Continuous observation 

With brachycephalic breed dogs, the ET should be removed as soon as possible to prevent airway obstruction.

True or False?

FALSE 

The endotracheal tube should be left in as long as possible because it provides a non-obstructed airway.

If removed, be preapred to re-intubate 

Causes of acute post-renal disease is often species specific. What is associated with:

A) Dogs

B) Cats 

C) Horses

D) Ruminants

Dogs - Ruptured bladder (HBC, trauma) 

Cats - lower urinary tract disease (infection, stones)

Horses - FOALS ruptured bladders 

Ruminants - Blockage (uroliths, etc)

What are the metabolic abnormalities as a consequence of acute post-renal disease?

Dehydration 

Metabolic acidosis 

Uremia (increased BUN, creatinine) 

Hyponatremia

Hypochloremia

Hyperkalemia

Respiratory compromise

What effect does acute post renal disease have on a patient's heart?

How can this be treated?

Electrolyte imbalances cause conduction interruption 

Myocardium should be stabilized with IV Ca Gluconate

Electrolytes can also be addressed by decreasing serum potassium. This is done by:

giving K+ free fluids,

Giving gluose + insulin (drive K+ into cells)

Sodium bicarbonate

KETAMINE 

Because it is excreted by the kidneys unchanged. 

Maintain renal blood flow - avoid hypotension, peripheral vasoconstriction

High fluid rate to premote diuresis 

Avoid drugs excreted unchanged by the kidneys, and NSAIDS

Stress/fasting disrupts blood glucose regulation, SO: give 1/2 insulin in AM, preform surgery early, quick recovery, feed as normal

Regulate BG before surgery, monitor intra-op. 

Decreased metabolism: decreased drug metabolism= delayed recovery, hypothermia

Obesity: can cause hypoventilation, may need IPPV

Peripheral neuropathy: can cause laryngeal paralysis

Check thyroid levels pre-op

Patients may have weakened muscles: may need IPPV

Hypercoagulable: decreased wound healing 

Drugs that increase Intraocular Pressure (IOP)

Ketamine, Tiletamine, Etomidate

Avoid ketamine, tiletamine, etomidate

Avoid vomiting - use anti-emetic (Cerenia) 

Avoid coughing/gaging at intubation

Avoid head down position - can cause venous congestion

Avoid hypoxemia/hypercarbia

Keep eye central: neuromuscular blocker, 

Control oculocardiac reflex: pressure on eye - bradycardia

treat with anti-cholinergics 

Provide adequate pre-med and sedation for recovery 

QUIET and SMOOTH recovery to prevent damage to 

eye

There is potential for PDA up to 6 days old

Avoid alpha 2 agonists 

premedicate with daizepam

inhalant induction with Isoflurane, Sevoflurane 

These animals have decreased protein binding, but increased BBB permeability. 

Also they have decreased metabolism (which will cause slower recovery) and decreased albumin.

Respiratory arrest 

Hypoxemia

Hypoxic myocardium 

CARDIAC ARREST

Cardiac arrest 

Tissue hypoxia 

Hypoxia of medullary respiratory center

Agonal gasps 

Respiratory arrest 

These are the causes of arrest 

HYPOXEMIA
HYPOVOLEMIA

HYDROGEN ION IMBALANCE

Hypo/Hyper KALEMIA

HYPOTHERMIA

When evaulating a patient that has arrested which of the following if FALSE regarding thier characteristics:

A) Small pupils = responsive to light

B) Large pupils = unresponsive to light

C) Capillary refill time will be decreased 

Pulseless ventricular tachycardia

Ventricular fibrillations

A) Airway 

B) Breathing 

C) Circulation 

D) Drugs 

E) Electrocardiogram

F) Defibrillation

Start chest compressions.

Although there are the ABC of resuscitation (Airway, Breathing, Circulation) 

CIRCULATION is the most important, so chest compression should be started immediately, providing the brain with oxygen. 

Place an endotracheal tube (PROPERLY) 

Administer 100% OXYGEN (turn off anesthetics) 

Flush rebreathing system

An IV line should be started in an arrested patient, even if it means stopping chest compressions to place it.

True or False?

FALSE 

Chest compression should NOT be stopped!!

Epinephrine - try a low dose first

(if there was bradycardia to begin with also, Atropine might also want to be used.)

Peripheral vasoconstriction

When you are preforming manual chest compressions you are only providing for about 10% of normal cardiac output. By initiating peripheral vasoconstriction there will be enough output to oxygenate the brain, which is your underlying goal.

Make a DIAGPHRAGMATIC incision

Animals that have an underlying process that would be adversely effected by the chest compressions. IE:

- Pneumothorax

- Chest Trauma 

- Hernia

- Pericardial/pleural effusion

Animals where chest compressions may not effect the heart, like with large barrel chested dogs.

10 minutes 

Although you can cotinue to perform resuscitations for 20 minutes, it is likely there will be neurological damage.

Chances of resuscitation survival without neurological damage = 5-10%

If you resuscitate a patient that was under anesthesia, it is ok to procede with the operation.

True or False?

Uh, FALSE 

You can reshedule the procedure for a month out.

Once resuscitated, the rearrest rate is as high as 70%.

True or False?

Resuscitation is almost always a failure in adult horses.

True or False?

TRUE 

But that doesnt mean you shouldn't try

Use LESS EPINEPHRINE

You can use your knee to manually compress the chest 

Lower rate of success

Inhalant

Anesthetics, carbon dioxide, carbon monoxide

Non inhalant

phenobarbital combination, potassium chloride

When euthanasia is preformed:

A) The heart stops first 

B) Respiration stops first 

C) Both heart beat and respiration cease together

Answer: B) Respiration stops first

This is why you need to check the heartbeat before you can consider the euthanasia complete.

Otherwise this happens...

http://www.aolnews.com/2011/03/02/wall-e-the-puppy-is-euthanized-but-survives/ 

Preplace IV catheter (prevents the stress of trying to find a vein while the owners are present and mourning)

Induce anesthesia with propofol (this prevents the animal from struggling, and prevents agonal gasping that may disturb owners)

Inject euthanasia solution IV 

Tranquilize 

Xylazine or Detomidine

Produce unconsciousness 

Ketamine + Diazepam

Initiate cardiopulmonary arrest 

Phenobarbital

The overdose of potassium causes electrical potential distrubances on the heart conduction causing

fatal cardiac arrhythmias

Large nerves are more susceptible to local anesthetics like Lidocaine.

True or False?

FALSE

SMALL diameter nerves, and unmyelinated nerves are more readily effected by lidocaine.