Anesthesia Exam 2

What are the five ASA status’s?

1. Normal Patient

2. Mild Systemic disease

3. Severe systemic disease that doesn’t incapacitate

4. Incapacitating disease that is life threatening

5. Not expected to live past 24 hours with or without surgery

What are examples of CNS functions to measure anesthetic depth?

Pedal reflex, palpebral reflex, lacrimation, eyeball position, jaw tone, swallowing reflex, anal reflex, muscle relaxation

What are examples of cardiovascular functions to measure anesthesia depth?

1. Heart rate

2. Palpate pulses

3. Blood Pressure

4. Mucous membranes

5. CRT

6. Central venous pressure

What are examples of respiratory functions to measure anesthesia depth?

RR, Depth of respiration, pulse ox, capnography, blood gases, TV

What is the general order of GA?

1. Obtain Patient

2. PE

3. Obtain protocol

4. Pre-med

5. Induction

6. Recovery

Where is the laryngoscope placed when intubating?

Base of tongue below epiglottis

Where should the ET tube stop?

Do not pass the bifurcation of the first rib

Why do we leak check before putting air in the cuff?

To not overinflate and cause damage

How do we tie in an ET tube?

On nose or behind head - tight enough that it won’t slip during procedure

How often are we recording vitals?

Every 5 minutes

How often are we monitoring our patient?

Always

Advantages of non-invasive BP

1. Simple/easy to perform

2. No health risk

Disadvantages of non-invasive BP

1. Less accurate

2. Cannot monitor all parameters

Advantages of invasive bp

1. Additional information

2. More accurate

3. Instant readings

Disadvantages of invasive BP

1. Risk of infection

2. Added prep time

3. Costly

How can we increase ax depth?

Increase gas, increase tidal volume/RR, Give more induction agent

How can we decrease ax depth?

Decrease gas, provide more oxygen, keep patient warm

What are the effects of temperature change

1. Decreases efficacy of drugs

2. Impairs clotting function

3. Prolongs patient recovery

4. Increased myocardial morbidity

5. Reduces resistance to surgical wound infections

Where does warmth escape from?

1. Open body cavities

2. Contact with cold surface

3. Wet patients

Where is temperature read most accurately?

Rectal

Methods for cooling off patients

1. Increased oxygen flow

2. Alcohol applied to foot pads

3. Cool water enema

When does recovery end?

When the patient has returned to a normal state

What is the best position for recovery

Head level or raised from body, sternal if possible

When do you typically extubate dogs?

1-2 good swallows or head movement

When do you typically extubate cats?

1-2 good swallows

Signs of airway obstruction

1. Increased respiratory effort

2. Struggling/excessive activity

3. Cyanosis

Drug classes that cause respiratory depression

Opioids, alpha-2s, inhalants

pH normal

7.35-7.45

paO2 normal

90-600

paCO2 normal

35-45 mmHg (SA), 45-55mmHg (LA)

HCO3 normal

18-26 mEq/L

TCO2 normal

24-26 mEq/L

O2 stat normal

>95%

BE normal

-5-5

Errors in pulse-ox readings

Dry tongue, pigmented tissue, outside lighting, vasoconstriction, anemia

Crystalloids molecular size

small

Crystalloids time in vessels

30-45 min

Crystalloids examples

Plasmalyte, LRS, Sodium chloride

Colloids molecular size

Large

Colloids time in vessels

Longer than crystalloids

Colloids synthetic examples

Vetstarch, hetastarch, dextrans

Colloids natural example

PRBC, whole blood, plasma, albumin

Pain pathway

1. Transduction

2. Transmission

3. Modulation

4. Perception

Drugs that act on transduction

Local anesthetics, NSAIDS, Opioids

Drugs that act on transmission

Local anesthetics, alpha-2s

Drugs that act on modulation

Opioids, NSAIDs, alpha 2s, dissociatives

Drugs that act on perception

Opioids and alpha 2s

What are examples of NSAIDS

Carprofen, meloxicam, robenocoxib

NSAIDs pain management

Treats mild pain

NSAID side effects

GI issues, renal toxicity, hepatic toxicity, platelet aggression

What are examples of local anesthetics?

Lidocaine, Bupivacaine, Mepivicaine

Local anesthetics - onset?

Lidocaine: 3-5 minutes Bupivacaine: 20-30 min Mepivicaine: 5-10 min

Duration of local anesthetics?

Lidocaine: 60-90 minutes Bupivacaine: 4-8 hours Mepivicaine: 2-3 hours

Local anesthetics side effects

local irritation and swelling

Non-pharmaceutical pain management

Physical therapy, low impact exercise, acupuncture, weight control, surgery

Where are ring blocks?

In the carpus

Why would you do a ring block?

Cat declaw

How do you do a bier block?

Tourniquet proximal with IV catheter distal

Where is a bier block located?

Cephalic or saphenous veins

Duration of a bier block

30 minutes

Where do you do a brachial plexus block?

Everything distal to shoulder joint

Why would you do a brachial plexus block?

Fracture repair or arthroscopy

Duration of brachial plexus block

Motor: 12-16 hours

Sensory: 9-12 hours

Where do you do an intercostal nerve block?

3 consecutive ribs caudally

Why would you do an intercostal nerve block?

Fractures and thoractomy

Where would you do an epidural?

Lumbosacral joint (L7-S1)

Why would you do an epidural?

Hindlimb surgery, tail/perineal surgery, abdominal surgery

What are the two techniques for an epidural

Hanging drop or lack of resistance

What are some contraindications of an epidural?

Septicemia, skin infection, coagulation problems, neurological patients, direct trauma to injection site

What are some complications of an epidural?

Neurotoxicity, paresis and hyperplasia, ventilatory impairment, urinary retention

Infra-orbital foramen dental block

PM3 to I1

Mental foramen dental block

PM2 to I1

Mandibular foramen dental block

M3 to I1

4 sources of problems

1. Human Error

2. Equipment failure

3. Surgical complications

4. Adverse reactions to drugs

Types of human error

1. Inadequate history or PE

2. Lack of knowledge

3. Incorrect drug administration

4. Inattentive

Types of equipment failure

1. Not serviced regularly

2. Unsure how to work equipment

3. Leak check failure

Types of surgical complications

1. Blood loss

2. Thoracic surgeries

3. Miscommunication

How much blood can a 45 kg dog lose?

8% of body weight → 3.6 kg

20% of 3.6 kg → 0.72 kg (approximately 0.72L or 720 mL)

Respiratory emergencies caused by us

Drug induced respiratory depression, improper placement of ET tube, improper cuff inflation, aspiration pneumonia, tracheal tear, apnea

Physiological respiratory problems

1. Pulmonary disease

2. Obese patients

3. Patient position

4. Hypoventilation

5. Hyperventilation

Cardiac emergencies

1. Hypoxia

2. Acid-base imbalances

3. Electrolytes imbalances

4. Autonomic imbalances

5. Hypothermia

6. Air embolism

7. Toxicity

8. Inappropriate drug administration

9. Shock

10. Anemia

11. Cardiac disease

Signs of cardiac emergency

1. Changes in HR

2. Changes in pulse quality

3. Prolonged CRT

4. Cyanosis

5. Abnormal respiration

6. Abnormal ECG

7. Changes in BP

What are underdeveloped body systems?

1. Cardiovascular

2. Pulmonary

3. Thermoregulatory

4. Renal

5. Hepatic

What is cardio output dependent on?

Heart rate

What is the contractility for cardiovascular system in neonates?

30%

What is the cardiac reserve for neonates?

Very little - watch fluids

What is the key to success for neonatal anesthesia?

1. Maintain HR

2. Constant ventilation

3. Maintain body temp

4. Reduce anesthesia temp

5. Reduce drug dosages

Common pre-meds for neonates

Opioids, benzodiazepines, anticholinergics

Drugs to avoid with neonates

Acepromazine, alpha-2 agonists

Common routes of induction for neonates

Face mask inhalant, nasotracheal tube inhalant, non-barbituates or neurosteroids

Place for catheters in neonates

Cephalic, saphenous, jugular, IO

True or false: All animals over the age of 6 are considered geriatric regardless of species

False - All animals over 8 or 75%-80% of their life expectancy

What should be avoided in geriatric patients?

Bradycardia, hypotension, vascular resistance

What drug should be avoided in myocardial disease patients?

Ketamine and acepromazine

What drug should be used with caution for respiratory patients?

Alfaxalone

Reduced hepatic function can lead to what?

Hypoprotenemia

What is normal urine production under anesthesia?

1-2mL/kg/hr

What should be avoided in order to maintain renal blood flow?

Hypoxia

Why is acepromazine best avoided specifically in geriatric patients?

Hypotension and liver metabolism

Why are anticholinergic agents best avoided?

Sinus tachycardia