ECP Flashcards
1
Q
What steps should be taken in getting an ECC hx?
A
HEAPC: History (incl. signalment, chief complaint, last normal, meds, etc.), Examination, Assessment, Plan, Communication
2
Q
What things do you need to remember for a capsule hx?
A
Age, breed, sex, neuter status Primary complaint, how long it has been going on for Appetite, water intake and activity Vacc status Any current meds
3
Q
What parameters should you check for a MBS assessment?
A
Cardiovascular: - CRT - mm colour - Heart rate - Cardiac auscultation - Pulse quality (profile, rate, rhythm) Respiratory - effort - rate - pattern - auscultation Nervous System - mentation - gait
4
Q
What are some causes of global hypoperfusion?
A
- Hypovolaemia (eg. haemorrhage)
- Cardiogenic (eg. valvular disease)
- Obstructive (eg. GDV)
- Maldistributive (eg. SIRS)
5
Q
What might cherry red gums indicate?
A
Carbon monoxide poisoning
6
Q
What is the normal heart rate range in dogs and cats? How about normal resp rate?
A
Dogs: HR 80-120, Resp 15-30
Cats: 160-220
7
Q
How might you expect the heart rate to differ in a dog with mild, moderate and severe hypoperfusion?
A
Normal- 80-120
Mild- 130-140
Moderate- 150-160 (pale mm)
Severe- 170-220 (grey/ muddy mm)
8
Q
What may cause paradoxical breathing?
A
- Upper airway obst.
- Diaphragm dysfunction
- Stiff lungs
- Pleural effusion
9
Q
What sign indicates impending resp arrest in cats?
A
Mydriasis
10
Q
Most dogs with aspiration pneumonia often have harsh lung sounds in which lung field?
A
Cranioventral lung fields
***dorsocaudal distribution in puppies with neurogenic oedema
11
Q
What are the stages of GA?
A
I: Disordered consciousness (more acute functions but unbalanced)
II: Excitement
III: Surgical anaesthesia
IV: Overdose
12
Q
What are the 6 ASA physical status groupings?
A
1: normal healthy patient
2: mild systemic disease
3: severe systemic disease
4: severe systemic disease which is a constant threat to life
5: can’t survive without op
6: brain-dead
13
Q
How long should you fast a monogastric animal befpre surgery? What about ruminants, small animals, birds, and neonates?
A
Monogastric- 12 hrs
Ruminants- 12-36 hours (withhold water for 12 hrs)
Others: Short to no fast
14
Q
How would you prepare a diabetic patient for surgery?
A
Normal meal and insulin night before. Then, ideally we would give a small meal at midnight with half the insulin dose and then check AM insulin. If normal (<500g/dL), no insulin, if >500, 1/2 dose AM insulin. If low provide supp glucose
15
Q
What are some examples of alpha2 adrenoceptor agonists?
A
Xylazine (both)
Medetomidine (SA)
Dexmedetomidine (SA)
Romifidine (LA)
16
Q
What are some examples of opioids used in vet med? What about benzodiazepines?
A
Opioids: methadone, Butorphanol, Buprenorphine
Benzos: diazepam and midazolam
17
Q
What are the main effects of Acepromazine (6)? What are some side effects (4)?
A
Tranquilizer, anti-arrhythmic, antiemetic, anti-histamine, spasmolytic, alpha2 antagonist
Side effects: Hypotension, collapse (Boxers), hypothermia, decrease seizure threshold
18
Q
What are the main effects of Alpha2 agonists? What are some side effects?
A
Dose-dependent sedation, analgesia, muscle relaxation
(resp dep, bradycardia, cardiac arrhythmias)
Side effects: Hyperglycaemia, diuresis, decrease intestinal motility, vomiting
19
Q
What are some side effects of xylazine?
A
Sensitze myocardium to catecholamine, emesis
20
Q
What are the main effects of benzodiazapines?
A
Anxiolytic Anti-convulsant Anti-arrhythmic Appetite stimulant Muscle relaxation Minimal CV and resp effects
21
Q
What are some effects of opioids?
A
CNS depression (excitment in horses/cats?) Resp system dep Histamine release GIT depression ADH release Hypothermia Emesis Change in pupil diameter
22
Q
What is buprenorphine? How long does it last?
A
opioid (mu partial agonist)
Lasts for 4-6 hrs in dogs and 6-8 in cats.
Onset begins 30-60 mins after IM injection
23
Q
What is butorphanol?
A
mu antagonist and kappa partial agonist
24
Q
What are some contraindications to the use of opioids?
A
Pre-existing resp depression, head trauma, pancreatitus
25
What is attenuation of an x-ray beam?
Prportion of x-rays that are stopped/absorbed by a given thickness of matter
26
What effects whether the x-ray photon gets transmitted, absorbed or scattered?
1. energy of x-ray (kVp)
2. Atomic number of absorber
3. Thickness and density of radiographed body part
27
Better contrast in radiographs are achieved with high or low kVp?
Low (less penetration, more absorption)
28
The Compton effect is influenced by what factors? How might it be avoided/minimized?
1. Very dense absorbers
2. Large volumes or irradiated tissue
3. High kVp settings
Minimized by using lower kVp and restricting the collimated field
29
What are some advantages and disadvantages of computed radiography?
```
Adv:
- digital image, great quality
- uses existing radiograph equipment
- less expensive than DR
Disadv:
- imaging plates needed
- minimal time saving
- need an image plate reader
```
30
What are some advantages and disadvantages of digital radiography?
```
Adv:
-No processing time
-good image quality
Disadv:
- More expensive
- image sensors are expensive to replace
- may need a new machine
- cant't perform cross-table radiography if in-built sensor
```
31
The spatial resolution of DR systems is less than or more than conventional film screen radiography?
Less
32
What are the 4 steps to digital image processing?
1. Histogram creation
2. Data adjusted for over or under exposure
3. Enhancement of image contrast (look up table)
4. Edge enhancement/ smoothing
33
What is a stochastic effect?
Increased risk with increased dose/ have no threshold. Cumulative
34
What are the 4 basic methods of monitoring for radiation exposure? Which is most common?
1. Optically stimulated Luminescent dosimeters (most common)
2. Thermoluminescent dosemeter
3. Film badges
4. Pocket Dosimeters
35
Occupational dose limits state the vets should not receive more than ........mSv per year averaged over consecutive years and should not receive more than ....... in any single year.
20 mSv
| 50 mSv
36
How can radiation exposure be minimized?
1. Reducing time of exposure
2. Increasing distance from radiation source
3. Shielding of x-ray tube, room, and body
37
What is the source of electrons in an x-ray machine?
Cathode (tungsten filament)
38
What are the two main types of radiograph machine anodes? What does the anode do?
Rotating or stationary. Get positively charged when radiographic exposure is made and electrical potential diff is applied across x-ray tube. Electron energy is converted to heat and x-rays
39
In relation to x-ray beams, what are the following?
a. quantity
b. quality
c. intensity
```
Quantity= number of x-rays produced. This is dependent on electrical current (mA)
Quality= energy of photons and their penetrating ability. this depends on kVp (potential difference)
Intensity= amount of x radiation per unit area
```
40
What is the rate limiting step in taking radiographs?
Ability of the anode to dissipate heat.
41
What is a collimator?
Device to limit thee shape of the primary x-ray beam.
42
What happens when you press the x-ray button half way and then all the way?
1/2 way->Cathode is heated by the cathode current and the anode starts rotating
full-> potential voltage occurs for set exposure time
43
What is a rectification circuit needed for in radiography?
To convert main AC to DC for a potential difference t be applied across x-ray tube
44
What are some advantages of a three-phase generator?
1. More power available to x-ray tube per unit time-> allows shorter exposure
2. Intensity of X radiation generated is higher
3. Radiation quality is greater bc it has less low energy x-rays
4. tube utilization is more efficient bc target is not bombarded
45
The tube rating of an x-ray machine is based on what 4 factors?
1. Focal spot size
2. Target angle
3. Anode speed
4. Electrical current
46
What is one possible risk of using negative contrast agents?
Wall of a hollow organ that has damaged mucosa can allow gas to gain access to the vascular space.
47
How might you minimise the risk of death from an air embolism when performing a pneumocystogram?
Place the patient in left lateral recumbency and use CO2 or NO which is more soluble than room air.
48
What two agents can be used for positive contrast radiography?
Barium (GIT tract only)
| Ionic agents
49
What are the two types of endotracheal tubes?
Murphy (has cuff and Murphy eye) and cole
50
What is a disadvantage of an endotracheal tube with a cuff?
In some species (eg. Birds), the tracheal ring is closed and cannot expand -> pressure necrosis.
51
What’s a disadvantage of rubber ET tubes?
Cannot see if it’s clean or not. Also need to put a lot of pressure to open cuff which makes it more difficult to judge how much pressure you are putting on the trachea
52
What is the purpose of an ET tube?
Allows sealing of airway to prevent aspiration and to provide positive pressure ventilation without air leaking
53
What are the two types of laryngoscopes?
Millers (straight)* and macintosh?
54
What are some indications and risks of mechanical ventilation?
```
Indications:
O2 failure, ventilation failure (high CO2), post cardio-pulmonary resuscitation
Risk:
O2 toxicity
Barotrauma
Cardiovascular depression
Infection
```
55
What are the different types of mechanical ventilation systems and what is most common? Give a breif description of each of these systems.
1. Controlled mandatory ventilation ** (during GA)
2. Positive and expiratory pressure* (Patient is mechanically ventilated. Helps keep airway open)
3. SIMV (in ICU. Ventilator takes over breath as patient starts to breathe- controlled. decreases breathing work)
4. PSV (decreases work of breathing; patient takes its own breath. ie. not controlled)
5. CPAP (patient breathing sponataneously eg. those used in sleep apnea in humans)
56
How might you monitor respiratory function in an anesthetized animal?
1. Resp rate, rhythm and effort
2. Hb O2 saturation
3. EtCO2
4. Arterial blood gases
57
What factors might affect pulse oximeter readings?
- methaemoglobin, carboxyhaemoglobin
- low saturation
- poor peripheral perfusion
- anaemia
- skin pigmentation, dyes, fluorescent light etc.
58
What are some causes of hypoxaemia?
1. Reduced partial pressure of O2 in the inspired air
2. Alveolar hypoventilation
3. Shunt
4. Impaired alveolar capillary diffusion
59
What are some advantages of using inhalant anaesthetics?
They allow:
easy and rapid control of patient depth and the use of supp O2.
They are also fairly cost effective
60
What is the SVP of an inhalant anaesthetic?
=saturated vapor pressure= measure of the liquid's ability to evaporate. (higher for Isoflurane than for sevoflurane)
61
The concentration of anaesthetic in the alveoli (at equilibrium) is a reflection of the concentration of anaesthetic in the brain. True or False?
True!
62
What factors affect the amount of anaesthetic reaching the alveoli? How may these factors be altered?
Inspired concentration of the anaesthetic and alveolar ventilation.
Inspired concentration can be increased by:
1. increasing vaporizer setting
2. increasing fresh gas flow (O2)
3. Decrease volume of breathing circuit
63
What is the functional residual capacity? How is this important in considering alveolar ventilation?
= volume of air left in lungs after normal exhalation
Alveolar ventilation follows time constants (FRC/ Va)
64
What factors affect inhalant uptake?
solubility, cardiac output, alveolar-venous pressure gradient
65
What has a higher blood:gas partition coefficient, Sevo or iso?
Iso. ie. it is more soluble and therefore has slower induction
66
What are some important points to remember about rabbits in relation to anaesthesia? (7)
- small lung volume
- obligate nasal breathers
- cannot regurgitate
- should not be fasted (gut stasis)
- blood can be taken from saphenous or jugular vv.
- catheter can be placed in marginal ear vein
- pre-med and oxygenation is essential
67
What can be used for pre-med and anaesthesia in rabbits?
Pre-med:
- butorphanol (IV/SC)
- Butorphanol and midazolam
Induction:
- midazolam, buprenorphine
- medetomidine and ketamine, buprenorphine
68
Assisted feeding in rabbits post-op is essential within the first 2 hours. How would you feed a rabbit if it doesn't lap voluntarily?
Syringe feed 20ml/kg by mouth using catheter every 2 hours
69
What are some important points to remember about rats/mice in relation to anaesthesia? (4)
- nasal breathers
- cannot regurgitate
- eyes will proptose easily when fitted with mask
- don't need to fast
70
What are some important points to remember about ferrets in relation to anaesthesia? (5)
- can regurgitate
- strong jaw tone that is slow to decrease under ga
- cephalic or saphenous for catheter (skin is thick and less elastic so may need to make incision)
- must be fasted prior to ga (4 hours or 2 for juvenile)
- anaesthesia should be delayed if any signs of endocrine disease
71
What are some important points to remember about pythons in relation to anaesthesia? (6)
- poikilothermic
- lungs are fragile and shouldn't be overinflated
- can breath hold
- IV catheter via cut down over jugular
- IV injection via caudal vein (caudal to cloaca)
- fluids may be given via intracoelomic injection
*** Similar for bearded dragons
72
What can be used to anaesthetise frogs?
Immersion in tricane methanesulfonate (note, they become apnoeic with immersion anaesthesia)
73
Where can IV injections be given in a turtle?
Jugular or dorsal venous sinus
74
How does a multidimensional pain scale work?
What ones are available for dogs?
Pain assessment scales that are a composite of simple descriptive scales relating to particular aspects of behaviour associated with pain. May also have a physiological component to them.
Dogs: Glasgow, Colorado and Melbourne pain scales for acute pain. Helsinki pain scale for chronic pain
75
What multidimensional pain scales are available for cats?
Acute pain: Glasgow, Colorado and UNSP Botucatu MDPS
| Chronic: QoL questionnaire
76
What is the most common cause of chronic pain in small animals? Why is it hard to recognise chronic pain?
Osteoarthritis
| Insidious in onset, subtle changes over a long amount of time, often associated with "growing old"
77
What are some pharmacological options for chronic pain therapy?
```
Oral opioids, transdermal fentanyl
NMDA antagonists
Mood altering drugs
NSAIDs
(Acupuncture analgesia and physiotherapy are other non-pharmacological options)
```
78
What is transdermal fentanyl and how does it work?
Class of opioid which changes how your body perceives pain. It provides long duration analgesia but has a slow onset time (~12 hrs in dogs-leave for 2-3 days; ~2hours in horses-leave for about 24 hours). It has a matrix transdermal system which releases fentanyl proportional to the SA it is in contact with
79
What is ketamine and what are its advantages and disadvantages in terms of its use?
NMDA receptor antagonist which targets receptors in the spinal cord. These receptors are activated by injury/ insult.
Ketamine:
-is implicated in the development of central sensitization (more sensitive to pain)
-is a sedative and analgesic (but can only be used in hospital)
-does not depress CVS or resp system
80
What are some NMDA receptor antagonists useful for management of pain? Which*** of these can be prescribed for at home use in animals?
Ketamine
methadone
meperidine
Amantadine*** (also an antiviral agent. It may decrease allodynia and hyperalgesia)
81
What is tramadol and what are its uses? In what species does it work particularly well in?
It's a centrally acting adjuvant analgesic drug which decreases serotonin and noradrenaline reuptake and acts as a weak opioid agonist.
Cats (not so great in dogs because it is not metabolised properly)
82
What is gabapentin? What are it's uses? How is it excreted?
An adjuvant analgesic drug which acts as an antiepileptic drug. It can be used for neuropathic pain, cancer, primary nerve compression and gives pain relief over several weeks.
Kidneys
83
What is Amitriptyline? What are some contraindications for this drug?
Mood altering drug that blocks noradrenergic and serotonin reuptake. Hence can be used for neuropathic pain.
CIs:
-seizure, urinary retention, severe liver disease, patient already on serotonin sparing drugs (note: takes about a week to work)
84
What are biphosphonates? What are some examples?
Drugs which inhibit osteoclast activity and thus give osteoblast cells a chnace to work. Used as adjuvant therapy for the management of osteosarcoma (or for horses with laminitis). They may also have a role in the inhibition of metastatic bone cancer cells.
Examples include: pamidronate (dog), tiludronate (equine)
85
What is the MAC? How does it relate to potency of a drug?
minimum alveolar concentration= percentage of inhalant that will prevent movement in response to supramaximal noxious stimuli in 50 of the pop. Inversely proportional to potency
86
What are the MAC values for Isoflurane and sevoflurane? Which is more potent?
Iso: 1.3%***
sevo: 2.4%
87
What is the "surgical MAC"?
| What is MACawake and MACbar?
```
ED95= 1.3 x MAC
MACawake= MAC in humans when eyes open in response to verbal command (lower than MAC)
MACbar= MAC necessary to prevent adrenergic response to surgical stimulation (higher)
```
88
What factors increase and decrease MAC?
```
Increase:
-drugs causing CNS stim
-hyperthermia
Decrease:
-drugs causing CNS depression
-hypotension
-hyponatraemia
-hypothermia
-hypoxaemia (<40mmHg)
-hypercapnea (>95mmHg)
-pregnancy
```
89
What is the normal PaO2 in an anaesthetised patient?
| What about the normal PaCO2?
500mmHg
| 40mmHg
90
What are some cardiovascular effects of inhalants (5)?
| What are some respiratory effects of inhalants(2)?
HEART:
- Decreased CO (negative inotrope)
- Variable effects on HR
- Decreased arterial BP
- Increased automaticity of myocardium
- Sensitise myocardium to arrhythmogenic effects of catecholamines
RESP:
- Dose dependent decrease in minute ventilation (bronchodilation)
- Increased PaCO2 (hypoventilation)
91
What are some CNS effects of inhalants (3)? What are some renal/hepatic effects (5)?
CNS:
- dose-related depression
- decreased cerebral metabolic oxygen requirement
- increased cerebral blood flow
RENAL/HEPATIC:
- decreased RBF and GFR
- methoxyflurane is nephrotoxic
- decreased hepatic blood flow
- decreased drug clearance capacity
- halothane hepatitis
92
What would you use to treat malignant hyperthermia resulting from inhalant anaesthetic?
Dantrolene
93
What is compound A?
Gas formed in rebreathing systems when sevoflurane is degraded by soda lime or baralyme. It is nephrotoxic in rats
94
Why is NO no longer used?
- Not inactivated by activated charcoal- can't be scavenged!
- Diffuses in closed gas spaces (pneumothorax, GDV etc)
- Not as potent as other drugs
- 2nd gas effect
- diffusion hypoxia (occurs if no O2 given after procedure)
95
What is the active ingredient in Frontline? How does it work? Is it locally acting or systemic?
What does it work on?
Phenylpyrazole: Fipronyl (adulticide) and S-methoprene
Works by blocking GABA-gated and glutamate-gated Cl channel leading to hyperexcitation of insect NS.
Translocated dermally
Adult fleas, egg dvpt, larvae and pupae
96
What is the active ingredient in Advantage? How does it work? Is it locally acting or systemic?
What does it work on?
A neonicotinoid- Imadocloprid
Acts selectively on insect nicotinic acetylcholine receptors and causes paralysis of nerve conduction and rapid death.
Translocates dermally
Adult felas and flea larvae
97
What is the active ingredient in Advantix? How does it work? What does it work on?
Pyrethrin which prolongs period of Na conduction in APs -> repetitive nerve firing.
Paralysis, bush and dog ticks
98
What is the active ingredient in Advocate? How does it work? Is it locally acting or systemic?
What does it work on?
Imadocloprid and moxidectin* (which is absorbed systemically*)
Adult fleas, larvae, roundworm, hookworms, heartworm (plus demodex and sarcoptes in dogs)
99
What is the active ingredient in Revolution? Is it locally acting or systemic?
What does it work on?
Selamectin
| Systemic
100
What is the active ingredient in Activyl? How does it work? Is it locally acting or systemic?
What does it work on?
Indoxacarb which causes irreversible hyperpolarization of insect nerve cell membranes by binding to sodium channels
Locally acting
101
What is the active ingredient in Bravecto? How does it work? Is it locally acting or systemic?
What does it work on?
Fluralaner (class: isoxazoline) which blocks GABA gated and glutamate-gated chloride channels
Systemically
Fleas and paralysis tick
102
What is involved in an integrated flea control program?
treating all animals with adulticide and IGR
Flea bombs/vaccuuming environment
wash bedding etc. ****95% of pop is off the animal!!!!!
103
What are the 9 commonly used classes of antibiotics in vet med?
1. Penicillins
2. Cephalosporins
3. Macrolides
4. Aminoglycosides
5. Tetracyclins
6. Sulfonamides
7. Fluoroquinolones
8. Metronidazole
9. Amphenicols
104
What are macrolides? Give an example.
Gram pos drugs used for resp, mastitis and prostates in LA. Some topical forms exist for smallies.
Eg. erythromycin
105
What are some examples of cephalosporins and what they are used for?
Cephalexin (1st gen)- skin, urine, osteomyelitis
Cefurioxime (2nd gen)- mastitis in cattle
Ceftiofur (3rd gen)- resp disease in cattle and horses
106
What are some examples of penicillins?
Amoxycillin- broad spec
| Clavulox
107
What are some examples of amphenicols and what they are used for?
Florfenicol- bovine resp disease and footrot (beef only)
108
What are some examples of metronidazole and what they are used for?
Flagyl- anaerobic infections (osteomyelitis, peritonitis)
109
What are some examples of fluoroquinolones and what they are used for?
Enrofloxacin (Baytril)- everything (banned in food producing animals)
110
What are some examples of sulfonamides and what they are used for?
Sulfadimidine- diarrhoea in LAs. Good penetration into gut, milk, lungs and urine.
111
What are some examples of tetracyclins and what they are used for?
Alamycin-broad spec
112
What are some examples of aminoglycosides and what they are used for?
Neomycin, gentamycin- LAs mostly
Gram negative and staph.
*Note: cause nephrotoxicity and residues in kidneys. Banned in food producing animals
113
In preparing an animal for US, why do we clip, apply alcohol and gel?
Alcohol "defats" the skin
Gel provides good acoustic coupling to reduce artefact and allow probe to slide over the skin. All of these measures help reduce the amount of air and decreases the difference between the relative acoustic impedences of air and soft tissue
114
What is the difference between the different modes of US?
B-Mode= brightness mode. Provides a real time cross-sectional 2D image
M-Mode=motion mode. Provides a graphical trace of motion over time (used for echos)
Doppler= provides information on blood flow. (BART)
a. Colour: Superimposes direction and velocity of blood flow over B-Mode image
b. Spectral: Allows quantification of velocity along a single scan line
i. Continuous wave (for high velocity flow)
ii. Pulsed wave
c. Spectral= B-Mode plus spectral doppler
115
How are US images formed?
B-mode images are formed by sending small pulses of high frequency sound into tissues and detecting the echoes that are reflected back
116
Diagnostic US uses what frequencies?
Between 2 and 20 MHz
117
The velocity of sound through soft tissues is nearly constant. True or False?
True (1540m/sec)
118
What determines the brightness of a displayed pixel in an US image?
What determines the degree of attenuation ?
The amplitude (high amp=incr. brightness)
Distance travelled and the frequency (Barry white concept). It is a reduction in sound due to absorption, scattering and reflection
119
What is acoustic impedence and what does it depend on?
=sound reflection or transmission characteristics of a tissue. Depends on the density of tissue and speed of sound within the tissue (which we assume is constant 1540m/sec)
120
What are the different types of US transducers? Which is best for vet abdo US? Probes can detect echoes reflected at what angle?
Linear
Curvilinear
Microconvex***
Phased Array
<3 degrees
121
What is time gain compensation?
Selective amplification of echoes according to their travel time.
122
What is contrast resolution in US?
Shades of grey. Affected by overall gain (ampl. of echo) and dynamic range (range of greys)
123
Briefly, how do these different artefacts arise?
- Shadowing
- Enhancement
- Reverberation
- Mirror image
- Slice thickness
- Shadowing: almost complete reflection or absorption of sound
- Enhancement: Increased echogenicity distal to a structure of low attenuation
- Reverberation: Production of spurious echoes due to 2 or more reflectors in the sound path
- Mirror image: Occurs with large deflector such as diaphragm
- Slice thickness:Occurs when part of US beam is outside a fluid filled structure
124
What is scintigraphy?
Imaging modality which involves giving animal a radioactive pharmaceutical and using a gamma camera to image the distribution of radioactivity. Technetium is most common (1/2 life 6 hours)
125
Bone scintigraphy is more sensitive at detecting bone lesion cff radiography. True or False?
True. It is however relativeky non-specific
126
What is commonly used for bone scintigraphy? what about thyroid scintigraphy?
Technetium-MDP
| TcOs (technetium pertechnetate)
127
What are some risks associated with anaesthetising horses?
- Neuropathy (radial nerve and facial)
- Myopathy (blood flow to both dependent and "up" limbs decreased)
- HYPP
128
At what level should you maintain MAP in an anaesthetised horse? What is the gold standard of measurement?
70mmHg (80 in a heavily muscled horse)
| Invasive (arterial) measurement (facial, mandibular, transverse facial, lateral metatarsal aa.)
129
What is HYPP? How can it be managed?
Hyperkalemic Periodic Paralysis= genetic disorder of Quarter horses in which the stress of sedation and anaesthesia can cause attack. (Witche's hat T wave)
Pre-treat both hetero- & homozygotes w/ acetazolamide prior to anaesthesia and careful intraoperative monitoring for signs of high K+
130
What is acetazolamide?
A diuretic which stabilizes K levels in the blood
131
Horses preferentially perfuse which lung fields? Assisted ventilation should be provided for procedures longer than...?
Dorsocaudal
| 45-60mins
132
If giving an opioid to an horse what is best? Why? What is a primary analgesic for horses?
Butorphanol- only lasts about 45 mins.
Note that all opioids decrease GIT motility and can cause excitement when given alone
Alpha 2 agonists (eg. xylazine)
133
What is an appropriate pre-med for horses (foals)?
What is an appropriate induction agent?
Alpha2 agonist +/- opioid +/- ace (inclusion minimises death) [benzodiazepine + butorphanol if very young and sick otherwise alpha2)
***note: horses are still sensitive to sound with alpha 2 pre-med
Induction: diazepam + ketamine (can also do thiopental, Guafenesin/ketamine, Xylazine/ketamine, zolitel) [facemask inhalant, propofol or alfaxan, ket/diazepam]
134
What are some methods of monitoring anaesthesia in a horse?
- ECG
- Capnography
- Periodic arterial blood gases
- Pulse oximeter
Plus:
eyes (not reliable with ketamine), pulse quality, mm colour, CRT
135
When anaesthetising foals, what things need to be considered?
- mare: my need sedation. will need to see foal ASAP
- immature liver
- immature thermogenesis
- more compliant chest and high RR
- immature SNS
136
What are some factors that may lead to emergencies in anaesthesia?
Incorrect drug admin, unfamiliarity with drug or machine, poor hx taking, lack of attention, fatigue, equipment failure, patient-related factors
137
What is the normal CO2 level in small animals? What is the permissive hypercabia?
normal is 35-45mmHg
Permissive hypercarbia < 60mmHg (this is where you let them hyperventilate a little bit bc elevated CO2 levels increase resp drive and stim symp NS to maintain HR and BP)
138
What are some solutions to anaesthesic hypotension?
1. assess depth
2. give anticholinergic????
3. increase fluid therapy
4. dopamine infusion- ephedrine
5. vasopressor (adrenalin)
139
At what level is bradycardia significant during anaesthesia? What are some drugs that can be used to treat it?
when it gets below 30% of normal
| Glycopyrrolate or atropine
140
What things might lead to hypoxaemia?
1. Low inspired oxygen
2. Hypoventilation
3. Ventilation-perfusion mismatch
4. Shunt
5. Diffusion impairment
141
What is flumazenil?
Antagonist for benzodiazepines
142
After the IV administration of a drug, what happens to the plasma concentration of the drug?
It rapidly decreases as a result of both distribution out of the vascular space and elimination
143
What factors determine the rate and seed of onset of anaesthesia?
```
Anesthetic used
dose
rate of admin
route of admin
cardiac output etc.
```
144
How long does thiopental generally last as a GA agent?
10-20 mins
145
What are the side effects of barbiturates?
CNS effects (depression, Allosteric modulators of GABA receptor, no analgesic effects)
CV (increase HR, decrease arterial BP, increased sensitive of heart to circulating catecholamine -> arrhythmias)
Resp (depression, post induction apnoea)
146
Does induction and arousal from anaesthesia by thiopental depend on redistribution or metabolism?
Largely redist. (5% hepatic metabolism per hour)
147
What are some precautions/ contraindications with thiopental?
```
Thin patients
Obese patients
Hypovolaemia
Age
Obesity
Hepatic dysfunction
Respiratory depression
Hypoproteinaemia
Strictly IV.
```
148
How does ketamine work? What would you combine it with?
It's a dissociative anaesthetic. It's a specific antagonist at glutamate NMDA receptor and at CNS muscarinic Ach receptors.
An agonist to opioid receptors- analgesic properties.
It causes functional dissociation between the thalamus and cortex
Benzos (must be used with muscle relaxant)
149
What are some side effects of ketamine?
-ve inotropic effect (weaken force of contraction)
incr. symp tone/ muscle tone
incr. HR and contractility/ hypertension
incr. CO and arterial BP
incr. myocardial oxygen demands
bronchodilation
Prolonged recovery
hallucinations/ delirium in recovery
150
How is ketamine metabolised?
Hepatic metab. Also excreted unchange via the kidney in cats
151
What are some contraindications for the use of ketamine?
```
epilepsy
brain disorder
cats with kidney dysfunction
glaucoma
***note: patient will keep oculopalpebral, laryngeal, swallowing reflexes and the eyes will be in place with slight nystagmus
```
152
What is tiletamine?
A dissociative agent similar to ketamine
153
What is etomidate?
Imidazole derivative not in Aust.
154
What is alfaxalone? What are some advantages? What are some of its side effects?
Steroid anaesthetic that modulates GABA transmission
Adv: doesn't accumulate in body, high therapeutic index, rapid recovery
Side effects: twitching/paddling in recovery, resp depr at induction, decr. arterial BP
155
What is propofol? What are some advantages and side effects?
A GABA-mimetic. Rapidly metabolised by liver.
Advantages: "to effect" induction, smooth rapid recovery, can use as CRI and in patients with hepatic disease
Side effects: CV depression, vasodilation, hypotension, apnoea, pain on injection. Don't use in cats.
156
How is propofol metabolised? What can you combine it with?
Hepatic metab. plus extra hepatic metab (lung, kidney blood?)
Thiopental
157
What is the triple drip?
Guafenazine, alpha2 + ketamine or thio
158
Can you use opioids as induction agents?
Yes, in combination with benzos if patient is debilitated
159
```
Describe clinical signs for the following levels of dehydration:
<5%
5-6%
6-8%
8-10%
>10%
```
```
<5%= not detectable
5-6%=dry mm
6-8%=dry mm, decreased skin elesticity
8-10%=as above + sunken eyes
>10%+signs of hypoperfusion (dull mentation, prolonged CRT, poor pulses)
```
160
What are some signs of dehydration cff hypoperfusion?
Dehydration:
- dry but pink mm
- skin tent
- quiet/normal mentation
- normal HR, pulses, BP and CRT
Hypoperfusion
- pale mm
- hypotension
- dull mentation
- tachycardia
- tall/narrow or short/narrow pulses
161
With chronic to severe hypernatreamia, should not drop sodium by >0.5-1 mmol/hr with fluid therapy. Why?
chronic hypernatraemia-> increase in neuron idiogenic osmoles to match ECF tonicity. Rapid correction of ECF hyperosmolality -> cerebral oedema
162
What is shock? Describe the pathophysiology of shock.
Severe haemodynamic and metabolic derangements that lead to an imbalance of O2 delivery and O2 consumption, leading to decreased cellular energy production.
Pathophys: progressive cell. dysfunction -> progressive organ dysfunction (SIRS and MODS) -> failure of compensatory mechanisms (incl. adrenalin, renin,
angiotensin, CO2 pathways)-> irreversible organ damage -> death!!!
163
What are the different classifications of shock?
Circulatory (hypovolaemic, distributive, obstructive, cardiogenic) and Non-circ (hypoxic, metabolic)
164
What are some causes of distributive shock (6)?
1. septic shock (SIRS)
2. anaphylaxis
3. severe acidosis
4. adverse drug rxn/ drug OD
5. electrolyte derangements
6. pharmacological vasoconst.
165
What are some signs of hyperdynamic (early) distributive shock? (How does this compare to hypodynamic distributive shock)?
hyperaemic mm, fast CRT, tachycardia, tachypnoea, normo/hypertension, tall narrow pulses
*****not in cats though (pale mm, hypothermic, lung=shock organ, HR up, DOWN or normal)
(pale mm, prolonged CRT, tachy/bradycardic, hypotensive, short pulses, altered mentation, peripheral oedema, pyrexia or hypothermia, hypotension)
166
What are some causes of obstructive shock (6)?
```
GDV
cardiac tamponade
aortic/ pulm. thromboembolism
pulm. hypertension
pneumothorax
neoplasia
```
167
What might cause metabolic shock (6)?
1. mitochondrial dysfunction
2. severe pH derangements
3. sepsis
4. cyanide toxicity
5. hypoglycaemia/ calcaemia
6. hyperkalaemia
168
What is the normal CaO2 of blood?
20ml O2/dl blood
169
What may cause hypoxic shock?
```
anaemia
severe pulm. parenchymal disease
hypovent.
carbon monoxide
dyshaemoglobinaemias
```
170
What are the 7 patient rights?
```
right patient
right route
right drug
right dose
right documentation
right technique
right time
```
171
What 8 things need to be included on drug labels?
```
Date of dispensing
Drug name and size/strength
Dosage
Patient/ client
Storage
Name/address of vet and clinic
FOR ANIMAL TREATMENT ONLY
KEEP OUT OF REACH OF CHILDREN
```
172
What is naloxone?
A reversal agent for opioids
173
What is a potential side effect of hydromorphone in cats?
Histamine release in critical patient
174
What are ways to objectively assess circulation to determine the need for fluid therapy?
1. ECG
2. Arterial blood pressure
3. Central venous pressure
4. Urine output
5. Lactate
6. PCV, TS
175
In what patients might you use an intraosseous catheter?
v. little patients or in adults where IV access fails
176
With acute rescus. fluid therapy, what dose would you give isotonic crystalloids to dogs/cats and over how long?
Dogs: 10-20 mL/kg per bolus
Cats: 5-15 mL/kg per bolus
Given over 5-15 mins
177
What are some indications for hypertonic saline fluid therapy? What are some contraindications?
Large dogs
rapid volume expansion
head trauma
CIs: dehydration, normovolaemia/hypervolaemia, hypernatraemia, renal disease
***Note: It retrieves fluid from the interstitial space. It is best used in combo with colloids
178
What are recommended doses for dogs and cat of synthetic colloids?
Dogs: up to 20 mL/kg total/ day
Cats: up to 10 mL/kg total/ day
5ml aliquots over 5-10 mins
179
What is the average blood volume in dogs/cats?
Dogs ~90ml/kg
| Cats ~50-60 ml/kg
180
What are some risk factors for fluid therapy?
```
Cardiac disease
Pulmonary disease
Incr. vascular permeability with inflammation
Generalised peripheral oedema
Sodium derangements
Coagulopathies
```
181
What are resuscitation nedpoints for fluid therapy?
```
HR decrease
MAP> 65-70 mmHg
Urine output >2mL/kg/hour
Lactate <1.5 mmol/L
PCV >20%
```
182
What things can mimic renal failure?
```
Medullary hypertonicity
Impaired ADH action
Hypochloridaemia
Hypoadrenocorticism
Hyperadrenocorticism
Diabetes insipidus
Pyometra
```
183
What are the three forms of icterus?
Pre-hepatic (haemolysis)
Hepatic
Post-hepatic (bile duct obstruction)
(anorexia in horses)
184
What are markers for cholestasis?
Increased bilirubin, ALP and GGT
185
What may be some biochemical findings with pancreatitis?
increased amylase and lipase, inflammatory leukogram, lipaemia, hyperglycaemia
186
What are some biochemical markers for muscle damage?
AST, CK and ALT (minor elevations)
**plus myoglobin in urine
187
What are some potential causes of hypercalcaemia?
Hyperparathyroidism, Addison's, Renal disease, Vit D toxicosis, Iatrogenic, Osteolysis, Neoplasia, Spurious, Granuomatous lesions
188
What might a low Na:K ratio be useful in assessing?
likelihood of hypoA (<25:1 is very highly likely to be hypoA)
189
What is sepsis? What is septic shock?
Life threatening organ dysfunction caused by a dysregulated host response to infection= systemic inflammation associated with infection
Septic shock= sepsis plus:
-vasopressor required for MAP >65mmHg
-lactate >2.0 mmol/L
despite adequate fluid resuscitation
190
What is SIRS?
Systemic inflammatory response syndrome= clinical syndrome of inflammation that may occur with or without infection
191
What is MODS?
Multiple organ dysfunction syndrome= derangements in organ function that arise from disruption in homeostasis that occurs in SIRS and sepsis
192
The pathogenesis of SIRS and sepsis involves loss of host homeostatic mechanisms. Describe this in more detail.
1. Loss of vasomotor tone: Endotoxin release and inflammatory mediators cause the release of NO- a potent vasodilator causing inapprporiate vasodilation in dogs (not cats) and tissue damage -> distributive shock
2. Dysregulation in coagulation and inflammation: decreased fibrinolytic and anti-coag processes lead to early hypercoagulability and reciprocal amplification of inflammation -> tissue hypoperfusion
3. Endothelial, mitochondrial and microcirculatory abnormalities: dysreg/ dysfunction of vasc. endothelial permeability, microcirc., and leukocyte/ platelet and mitochondrial function -> microcirculatory and metabolic dysfunction
All lead to tissue hypoxia -> MODS -> death!!!
193
What are some inflammatory parameters that may occur with sepsis? What are some other biochem changes that may help with recognition?
Neutrophilia, neutropaenia, left shift, toxic change, monocytosis
hypoglycaemia (after high glucose first)
hypoalbuminaemia (inc. loss and decr. pdn)
ionised hypocalcaemia
hyperbilirubinaemia (bact. byproducts alter Bb movement)
hyperlactataemia (due to decreased O2 delivery)
194
What causes increased lactate in septic effusions?
Not completely understood but likely associated with cellular and bacterial metabolism and tissue anaerobic metabolism
195
What are some parameters that may help in the recognition of DIC (6)?
1. thrombocytopaenia
2. Prolonged PT
3. Prolonged PTT
4. Prolonged ACT
5. Elevated d-dimer
6. Elevated fibrinogen degration products
196
What are the 4 SIRS criteria in cats?
1. Rectal temp >39.7 or <37.8
2. HR >225bpm or <140
3. Resp rate >40 breaths/min
4. WBC count >19,500 or < 5000
197
Wha t are some examples of four quadrant therapies useful in septic patients?
1. Ampicillin and enrofloxacin or gentamycin
| 2. chloramphenicol
198
What method of haemostasis provides the best haemostatic security?
ligation
199
What is a transfixing ligature used for?
Large bvs or vascular pedicles when incr. security is required. Typically placed after and distal to a simple ligature
200
What are the four different laparotomy approaches?
1. Ventral midline
2. Paracostal
3. Flank
4. Retroperitoneal
201
In doing a laparatomy, describe a systemic approach you would use and what organs you would expect to find where.
1. Cranial and cranial left quadrant: diaphragm, liver and gall bladder, stomach
2. Cranial right quadrant: duodenum, pancreas, portal vein and caudal VC and right kidney/adrenal
3. Caudal left quadrant: spleen, rectum/ colon, caecum, mesenteric root amd LN, ileum/ jejunum, duodenal colic ligament, mesocolon (retract to see left kidney and adrenal and aorta
4. Caudal right quadrant: bladder and ureters, prostate/ueterus/ovaries, L limb of pancreas through omental bursa
202
How would you take a GIT biopsy?
From oral to aboral using #11 scalpel blade and skin punch biopsy
203
When closing after a laparotomy, in which direction should you stitch? What is the most important layer in this closure?
In caudal to cranial direction. 6-8 throws at each end. The most important tissue is the external rectus sheath
204
What are some indications for laparoscopy?
- abd. cryptorchid testes
- oviariectomy/ ovariohysterectomy
- liver biopsy
- lap-assisted gastropexy or cystotomy
205
The principles of cancer diagnosis requires answers to which questions?
1. What is it? (neoplastic or not, cell of origin)
2. How bad is it? (benign or malignant)
3. Where is it?
206
What gauge needle would you use for most FNAs?
22g
207
What are some limitations of FNA for mass/ lump diagnosis?
- small potentially unrepresentative sample
- mass may be poorly exfoliative
- lacks architecture
208
What are some indications for biopsy?
- if FNA cytology is non-diagnostic or equivocal
- type/extent of treatment may be altered
- O willingness to treat would change
- grade and plan Sx
- prognostic purposes
- reconstructive surgery req'd
209
How will pathologists grade tumours?
1. degree of cellular differentiation
2. number of mitotic figures
3. degree of necrosis/ haemorrhage
4. evidence of local invasion
5. presence of metastasis
210
What is the TNM system?
```
T= tumour characteristics
N= regional lymph node involvement
M= metastatic involvement
```
211
What are some important intra-operative considerations when removing a tumour?
- early ligation of vascular pedicle
- gentle tissue handling
- lavage and new gloves for wound closure
212
Masses with high likelihood of local occurrence should be resected with_________lateral margins and ______.
2-3 cm lateral margins and one fascial plane deeper than compartment of origin
213
What is cryosurgery? How does it work?
Freeze/thaw cycles to destroy tissue. It causes:
1. ice crystal formation which disrupts cell membranes during freezing and thawing cycles
2. conc. of unfrozen solutes creates osmotic gradient and dehydration
3. vasc. collapse and thrombosis in small vessels
214
What cryogens are frequently used?
Nitrous oxide and liquid nitrogen
215
Orthovoltage energy is preferentially absorbed by which tissue? (radiation therapy) What is this type of radiation therapy best for?
Bone (due to the photoelectric effect)
Supfl. tissue lesions
216
How does megavoltage differ to orthovoltage?
Provides a higher energy beam
Reduced dose delivered to skin (penetrates deeper)
Energy is delivered via Compton effect
217
With reference to radiation therapy what are early and late responding tissues?
Late: express effects of radiation over longer time frame. Include bone, neural tissue, muscle lungs)
218
What are the hallmarks of cancer?
```
Self sufficiency from growth factors
insensitivity to anti-growth signals
evasion of apoptosis
limitless replicative ability
sustained angiogenesis
invasion and metastasis
```
219
What are some common chemotherapy side effects?
Bone marrow suppression: neutropenia, thrombocytopenia, anaemia
Alopecia/skin lesions: perivascular irritants (esp. doxorubicin)
Gastrointestinal problems: vomiting, nausea, diarrhoea
220
How might you minimise chemotherapy exposure?
closed-system administration, PPE, spill kits, don't crush or split pills, don't compound into liquids, gloves when cleaning, dilute bleach when cleaning
221
What are some important physiologic considerations when anaesthetising small ruminants?
- Fasting doesn't completely prevent regurg and aspiration
- anticholinergics cause increase in viscosity of saliva -> possibility of obstruction
- dorsal recumbency should be kept to a minimum (diaphragm and caudal VC)
- use cuffed ET tube
- place in LEFT lat recumbency for intubation
222
Where should a catheter be placed in small ruminants during GA?
Jugular (secure in place with a coupe of sutures)
223
Which drug may cause pulmonary oedema in sheep?
Xylazine
224
What is a safe sedation protocol for sheep?
| What is a safe induction protocol for sheep?
diazepam or midazolam + butophanol or buprenorphine
lignocaine (2mg/kg) over 2 mins followed by thiopental (or propofol or alfaxan)
225
Iso can be used for maintenance of GA in small ruminants. There are also other parenteral options. Give examples of these and list some pros/ cons.
Good in field
more costly, require more intensive monitoring, risk of prolonged recovery, still need to intubate
Eg. propofol, propofol + ketamine, alfaxalone
226
Eye movement is a useful indicator of anaesthetic depth in sheep. True or False?
False
227
How might you treat hypotension in an anaesthetised small ruminant?
1. check anaesthesia depth
2. check HR
3. rapid fluid admin
4. IV dobutamine, dopamine
5. vasoconstrictors as last resort
228
To avoid ruminal tympany and regurgitation, ruminants recovering from GA should be...?
Placed in sternal recumbency with the ET tube left in place (cuff inflated) until swallowing reflex is observed
3. keep cuffinflated until
229
Where is a paravertebral block done?
Locate L1 transverse process, insert spinal needle 2.5-3cm lateral to dorsal midline until it hits TP. needle is then walked off the cranial edge and advanced approx 1 cm (go through intertransverse lig). 2 mL local given and then needle is withdrawn ~1cm to give another 1 mL. Done for L2 and L3 (block T13, L1 and L2 nerves)
230
What are your landmarks for a cranial epidural? Where does the needle penetrate?
Lumbosacral space. Needle is inserted into ligamentum flavum
231
Which nerves are blocked for dehorning goats?
Cornual branches of zygomaticotemporal and infratrochlear nerves
232
When should you avoid the use of NSAIDs?
```
GI injury and inappetance
volume depletion (including vomiting/ diarrhoea)
renal or hepatic disease
impending surgery
bleeding tendency
```
233
What might you use to treat concurrent CS and NSAID use?
Misoprostol (to prevent stomach ulcers)
234
What are some examples of topical CSs and examples of otic preps?
Topical- neocort and elocon
| Otic- canaural, aurizon, mometamax
235
What is serotonin syndrome?
Seizures, hyperactivity, V+, D+, hyperthermia, hypertension and tachypnoea caused by SSRIs, TCAs (tricyclic antidepressants) and MAOIs (Monoamine oxidase inhibitors) given together
236
What other therapies might you administer along with fluids for the different types of shock?
1. Hypovolaemic: special fluids, bloods
2. Cardiogenic: inotropes, anti-arrhythmics, diuretics
3. Distributive: Vasopressors, A/bs
4. Meatbolic: GCs, dextrose, calcium
5. Hypoxic: Oxygen, ventilation
