ECP 1 Flashcards
Dog and cat HR, RR, temp
HR - Dogs 80-120 bpm
Cats 160 - 220 bpm
RR - 15-25bpm
Temp -
What is Saturated vapor pressure and what helps with
- SVP = measure of liquids ability to evaporate
allows us to predict the maximum percentage of that anaesthetic that can be achieved
Sevoflurane lower saturated pressure than isoflurane
Maximum percentage is lower than isoflurane
What are the 2 things that affect the amount of anesthetic reaching alveoli (at equilibrium reflects the brain)
1) inspired concentration of anesthetic (vaporiser setting)
2) alveolar ventilation - deeper and increased
What are the 3 things that affect anaesthtic uptake into the blood and what does it do to anaesthetic induction
Anything that pulls more anaesthetic from the alveoli will slow anaesthetic induction (alveolar won’t be able to fill up and build concentration gradient)
1) Solubility - MORE soluble taken up from alveoli faster therefore SLOWER induction
2) Cardiac output (CO) - INCREASED more anaesthetic picked up therefore SLOWER indution
3) Alveolar-venosus pressure gradient - INCREASED more movement SLOWER induction
Distribution of inhalant anaesthetic into the tissues what are the 3 things its dictated by and what causes faster
1) % CO to tissues - INCREASED - faster
2) Volume of tissues - LOWER body weight - faster
3) solubility in tissues - INCREASED - faster
MAC what is it, what is it a measure of and the relationship, where measured how differs
The percentage of inhalant in the alveoli that will prevent movement in response to supramaximal noxious stimulus in 50% of the population (equivalent to ED50)
- MAC is a measure of anaesthetic potency (how much concentration needed to accomplish what is needed)
- Higher MAC LESS POTENT -> higher concentation to accomplish anaesthesia
- Measured at equilibrium between alveoli and brain
- AKA - the ED50
- Differs slightly between species
List 2 factors that increase MAC and many more than decrease MAC
Factors that INCREASE MAC - Drugs causing CNS stimulation - Hyperthermia Factors that DECREASE MAC - Drugs causing CNS Depression - Hypotension (<50 mmHg) - Hyponatraemia - Hypothermia - Hypoxaemia (PaO2 < 40 mmHg) - Hypercapnoea (PaCO2 > 95 mmHg) - Pregnancy (need less anaesthetic)
Inhalants 3 CNS effects, 3 respiratory and 4 cardiovascular effects
CNS
1. depression 2. decreased oxygen requirement 3. increased cerebral blood flow
Respiratory
1. minute ventilation reduced as tidal volume reduced 2. bronchodilation 3. Increased PaCO2 -> hypoventilation
Cardiovascular
1. decrease CO 2. decrease aterial BP 3. increase automaticity of myocardium 4. sensitize myocardium to arrhthmogenic effects of catacholamines (halothane - newer less common)
Nitrous oxide why don’t use (3 reasons) and what is main effect
1) Higher MAC in animals compared to humans
○ Not as potent
2) Diffuses in closed gas spaces (gi tract, etc)
○ Pneumothorax, GDV, Colic, Bloat -> further inflate
3) Not inactivated by activated charcoal
○ Exposure risks
○ Environmental pollution
Main effect – “Concentrates” other inhalant in alveoli - speeds up induction (2nd gas effect)
What is the effective dose limit for radiography for vets and the general public, what is the average for vets
Effective dose limit
Occupational - 20mSv per year
General public - 1mSv in a year
Average - 0.015mSv
What makes up quantity of an X-ray and what settings controlled by
he number of x-ray photons produced
- Controlled by the mA setting: higher filament current = more electrons = more Xray photons
- Controlled by the ms setting: longer exposure time = more electrons reach the anode = more Xray photons
- mA and ms are often regarded together, as mAs
What makes up quality of an X-ray and what setting is it controlled by
is the energy of the x-ray photons - Controlled by the kVp setting higher potential difference between cathode & anode - most important for penetrating power = more rapid acceleration of electrons = higher energy electrons = higher energy x-ray photons
What are the 3 movements of xrays and what is this called
- The x-ray photon passes straight through: TRANSMISSION
- The x-ray photons can be absorbed. They undergo the PHOTOELECTRIC EFFECT
- The x-ray photons can be scattered. They undergo the COMPTON EFFECT
What does absorption of x-ray depend on an the effect involved what makes higher absorber
- Absorption of x-ray photons depends on the ENERGY of the photon and the ATOMIC NUMBER of the absorber (bone - calcium)
Photoelectric Effect - 2 things that relate to the probably of photoelectric effect occurring
○ Lower energy photon (low kVp level) hits an electron and is absorbed
○ Higher atomic number absorber = high electron density = photon more likely to collide and be absorbed
BONE - biggest absorber in body
Compton effect what type of photon undergoes this and then what occurs
Compton scatter is likely to occur with dense absorbers, large volumes of tissue, and high kVp settings
- High energy photon (high kVp settings) = hits an electron and is deflected, losing some energy
- Scatter radiation has low energy
- Scatter radiation does not travel along the path of the primary beam so just darkens the image without giving useful information
Ejects an electron so is also an ionising event
What are the 3 main negative effects of scatter radiation
Scatter radiation has no use in diagnostic radiology Negative effects of scatter radiation 1. Increase operator dose 2. Increase patient dose 3. Decrease image contrast
What is/result from with quantum mottle, double exposure and moire artefact
IMAGE ARTEFACTS
Quantum mottle
- Underexposure of a digital image -> not enough photons -> not clear depiction of anatomy -> low mAs
Double exposure
- Digital radiograph appears as two clear images
Moire artefact
- Occurs when a grid with the wrong grid ratio is used and misaligned
○ Creates a pattern of interference with the digital read-out frequency
Edge definition what are the 3 components and what makes edge definition is sharpest with
1) focal spot size - smaller focal spot better edge
2) focal spot to film distance - larger distance (generally 1m) the better edge
3) object to film distance -> smaller the distance the better edge definition
What are the 3 common antiseptics for skin preparation and their characteristics
1) Chlorhexidine gluconate
- G+/G- bacteria, viruses and fungi NOT sporicidal
- residual action (6 hours), not inactivated by organic materal, diluted in wounds 0.05%
- not compatible with iodine
2) Povidone-iodine
- bactericidal, fungicidal, virucidal may be sporicidal
- low residual activity, inactivated by organic material
- high incidence of skin reactions
3) alcohols
- ○ Most RAPID and effective antibacterial antiseptic (including MRSA & MRSP)
○ Bactericidal, fungicidal, variable against viruses and ineffective against spores.
○ Most effective at 70%
○ Evaporates very quickly - minimal residual effect so never used ALONE
○ Tissue necrosis in open wounds
Monofilament vs multifilament what are the advantages and disadvantages and which is preferred
Monofilament: preferred - Less pliable - Poorer handling, increased memory - Less tissue drag - Less knot security, more knots required. Multifilament: - Greater strength and pliability - Improved handling compared to monofilament - Increased capillarity - Increased tendency for bacterial colonization - Avoid in contaminated environments - Greater tissue drag - Increased knot security
What are the characteristics of positive contrast agents and the 2 main examples
Positive contrast agents have high atomic number and are efficient absorbers of x-rays
1) Barium - not IV or to go outside GIT tract
2) Iodinated contrast (non-ionic) - IV and excreted in kidney
What are the percentages in terms of body water within the body
Total Body Water = 60% of BW (kg)
- ICF (intracellular fluid) = 67% of Total body water
- ECF (extracellular fluid) = 33% of Total Body water
○ Interstitial - 75% of ECF
○ Intravascular - 25% of ECF
Total blood volume (dogs) = 25% of 33% of 60% = about 8% BW or 80ml/kg Cats about 60ml/kg
Clinical assessment of shock what are the clinical signs for milk, moderate and severe and which shock doesn’t go through this pathway
Mild -> increase pulse and heart rate due to sympathetic drive body responding
Moderate -> heart rate increased, starting to get pale, femoral pulse reduced, metatarsal bearable
Severe -> grey/white, dull, severely decreased pulses
- All go through this pathway except for distributive
Distributive shock what are the main clinical signs in dogs and cats
- Hyperdynamic (early)
○ Hyperaemic mucous membranes
○ Fast CRT
○ Tachycardia, tachypnea (bounding pulses)
○ Normotension or hypertension
○ Tall narrow pulses
Cats are different! - always pale, smaller increases in heart rate
Blood transfusion target, how to achieve and what need to do
○ Replace what is lost (estimate) ○ Target PCV > 20% - To increase PCV by 1% ○ Packed red blood cells: 1ml/kg ○ Whole blood: 2ml/kg - Cats: always blood type
leukogram what are the 3 main types and characteristics
- Is there evidence of an inflammatory response?
○ Neutrophilia and/or monocytosis
○ Left shift (bands) or toxic change -> ALWAYS INFLAMMATORY - Is there evidence of stress response?
○ Lymphopenia (most consistent finding)
○ +/- mature neutrophilia
○ +/- monocytosis (dogs) - Is there a physiologic leucocytosis?
○ Mature neutrophilia and lymphocytosis in young animal
What are the 3 main questions when assessing liver damage
- Is there evidence of cell damage?
○ Increased ALT, AST, GLDH, SDH - Is there evidence of cholestasis?
○ Increased bilirubin, ALP, GGT - Is there evidence of hepatic insufficiency?
○ Decreased urea, cholesterol, albumin, glucose
○ Increased unconjugated bilirubin
Acepromazine what is it, main effects, onset of action, duration
- Dopamine antagonist - sedation- reduces anxiety and awareness
- DOESN’T lower the seizure threshold
- Anti-emetic, anti-histamine, anti-nausea
- Anti-arrythmia - decrease myocardial sensitivity to catecholamines -> reduced risk of dying!!!!
○ Only drug to show this in dogs, horses maybe cats - IM - 30-40mins onset of action, IV 10-15mins
Lasts 6-8 hours - Prolonged especially for short procedure
Acepromazine downfalls, what patients good for and contraindications
- Causes vasodilation
- No reversal drug
- Stallions -> priapism - use with caution - not permanent
○ Worried in recovery as can step on them
GOOD - Healthy active patients
- Some cardiac patients (afterload reducer) - mitral valve regurgitation good
○ NOT CARDIAC FAILURE or DCM (no problem with afterload anyway)
Contraindications - Severe liver dysfunction
○ Liver metabolism - Not if in a hurry
What are the 6 main effects of alpha2-agonists
1) dose-dependent sedation (way stronger than ACE) / hypnosis
2) Analgesia (very good)
3) Muscle relaxation (very good)
4) respiratory depression (mild)
5) initial period of hypertension, followed by a more prolonged normotensive (?) phase
○ Reflex bradycardia - LOW HR
6) cardiac arrhythmias (where A-V blocks 1 and 2) -> no ventricular complex
Alpha-2 agonist, the 4 main types and how long last, what good for
Examples
- Xylazine - 15-30mins - pre-med
- Romifidine/ Meditomidine (dog) - 45mins
- Detomidine - 1 hour
Good for:
- Aggressive animals - PROFUND SEDATION
- Diagnostics - short procedures as can reverse
- CV and hemodynamically stable
- GOOD ANAGLESIA FOR VISCERAL ANAGLESIA - muscle relaxation - GOOD FOR COLICKY HORSES
Alpha-2 agonist side effects and contraindications
Side effect:
- Diuresis - horse problem which is often why urinary catheter is placed
- Anti-insulin -> increase glycogen -> hyperglycaemic
○ Can use in diabetics as already insulin insensitivity
Contraindications
- Functional cardiac problems or haemodynamic instability (profound anaemia, dehydration, hypovolaemia)
What are the 7 main effects of Benzodiazepines
- muscle relaxation - good
- anxiolytic
- appetite stimulation - used for this
- minimal cardiovascular and respiratory effects
- anti-convulsant
- potential for complete reversal (flumazenil)
- anti-arrhythmic
What patients are benzodiazepines good and bad for and why
are excellent agents for sedation in the “poor risk” patient, either alone or in combination with opioid drugs.
- Cardiovascular or respiratory compromise -> SICK GOOD DRUG
The benzodiazepines are unreliable agents for sedation in the “healthy adult” patient
- Due to anxiolytic properties -> brain unreliable, may have sedation and may not
What are the 3 classifications of opioid efficacy and examples of drugs within
1) Full (pure μ) agonists - BEST
○ morphine, methadone, meperidine, hydromorphone, fentanyl, alfentanil, remifentanil
2) Partial μ agonists - UNRELIABLE - need to give 2 doses, one before and one afterwards
○ buprenorphine
3) κ agonist – μ antagonists - excellent for sedation but poor analgesia (EXCEPT IN REPTILES)
○ butorphanol, nalbuphine
Opiod CNS, CVS, respiratory effects and 6 others
- CNS - Depression vs excitation (horses, cats? - need to use less)
- CVS- Minimal effects
○ Possible sinus bradycardia (vagal centre) - usually the blood pressure is maintained - Respiratory system
○ Depression
○ Drug and dose-dependent
Others… - Histamine release (pethidine - DON’T GIVE IV, morphine)
- GIT depression
- Release of ADH (urine retention)
- Hypothermia (but sometimes hyperthermia in cats, horses, swine…..CNS excitation? )
- Emesis (chemoreceptor trigger zone)
- Pupillary diameter (miosis in dog; midriasis in cat) - dog has O - miosis etc. -> if working in eye don’t give - IMPORTANT
What 2 poioids that lead to vomiting/nausea and when don’t want that
hydromorphone, morphine □ WHEN DON’T WANT TO -> increase intra-cranial pressure, obstruction, GDV, oesophageal FB, high ocular pressure (glaucoma and deep ulcer (barking can also increase intra-ocular pressure)) - so use methadone
Methadone, hydromorphone characteristics
§ Methadone -> analgesia (NMDA antagonist + pure mu pathways) and don’t want to vomit
§ Hydromorphone -> good sedation - can be stand alone
□ Give maropitant 30-60mins before to reduce risk of reflux and aspiration pneumonia
® Maropitant - NK-receptor analgesia (complementary not good enough alone)
List 3 contraindications for opioids and why
- Pre-existing respiratory depression
- Head trauma - increase CO2 due to respiratory depression which increases intracranial pressure
- Pancreatitis - unsure
Buprenorphine what does it provide, onset, duration, what is importnat to remember and what good for
§ Some analgesia - mild to moderate pain (moderate = spey with experienced vet)
§ No meaningful sedation (no complimentary sedation which is wait is normally) - NOT NORMALLY USED AS PREMED
§ Onset - 30-40mins - have to be organised
§ Duration - 6-8 hours good for post-op period
§ High affinity to mu receptor - IMPORTANT IF GO TO SURGERY POSSIBLY THEN DON’T GIVE -> have to give high levels of pure mu
□ When in doubt use a pure mu opioid
§ Good for
Desexing, endoscopy, diagnostics
Butorphanol what good for, used in, when used, onset and duration
NOT GOOD ANAGLESIC unless you are a bird (have all kappa receptors)
§ Used in horses as causes less ileus so just additive for analgesia as using alpha-2 that is good
§ Sedation in dogs and cats -> little to no pain expected
□ Butorphanol + medetomidine - can use less drugs and just get sedative for diagnostics
§ Good for
□ Non-painful diagnostic procedures
§ Short acting - 1 hour duration
§ 5mins IV, 10-15mins IM
Geriatric and young anaesthetic what want, PM and induction used
- Want minimum cardiovascular effects + short acting + quick
- PM -> methadone or hydromorphone for surgery, butorphanol if no surgery
- No acepromazine or medetomidine
- Induction - propofol and midazolam
Barbiturates CNS, CV and respiratory effects
CNS - depression, NO ANAGLESIA
CV - increase HR, decrease BP, increased sensitivity of myocardium to catecholamines
Respiratory - apnoea, decreased ventilation rate and tidal volume
What are the 6 main precautions when using thiopental
1) IV only!!!!
○ Skin slough - treatment saline and lidocaine
2) Thin dogs - main way to wake up is redistribution into fat, less fat -> less redistribution -> longer recovery
3) Hypovolaemia
4) Liver dysfunction - due to liver metabolism
5) Age - again metabolism is an issue
6)Obesity - calculate the dose without the fat content as redistribution will occur, overdose is common
Ketamine CNS effects
CNS stimulation
- Increase ICP (intracranial pressure) - if use muscle relaxation may decrease
- Might cause seizure in dogs and cats - history of seizures DON’T USE
- Analgesia somatic > visceral
- NMDA antagonist (chronic pain)
- Hallucinations/delirium in recovery
What are 7 important summary facts about ketamine
- Not for epileptic patients or brain disorder
- Increases sympathetic tone
- Not in cat with kidney dysfunction
- Provides analgesia
- Must be used with muscle relaxant
- Patient will keep oculo-palpebral, laryngeal, swallowing reflexes and the eyes will be in place with slight nystagmus
- Not in glaucoma or “brain” patient
Propofol side effects, how inject, shelf-life, contraindications
- CHEAP
- Dose dependent cardiovascular and respiratory effects
○ Same as alfaxalone EXCEPT when reduction in blood pressure generally HR doesn’t compensate - Slow administration to reduce apnoea is debatable -> give 1mg/kg over 30seconds
- No SQ or IM injection
- Discard in 8 hours of use - shelf life of 1 month
- Contraindications - SOME
○ Not used in cases of pancreatitis (has been an issue in humans)
○ If risk of septicaemia DON’T USE - if giving infusion
○ CRI infusion possible risk in cats so don’t do
Alfaxalone side effects, other main effects, injection, shelf-life and contraindications
- Dose dependent cardiovascular and respiratory effects
○ Cardiovascular depression -> reduction in heart rate, blood pressure, contractility - HR can compensate
○ Respiratory effects - apnoea - Muscle relaxation NO ANAGLESIA
- Can be given - SC, IM AND IV
- Once opened use within 24 hours or place within fridge for 7 days
- NO CONTRAINDICATIONS
Foal anaesthesia premedication examples
- Benzodiazepine (sedative in foals) + Butorphanol – great sedation/premedication for very young &/or sick foal
- Alpha 2 Agonist for older/robust foals
What are the 3 different light requirements for reptiles and what reptiles need what
○ UVA, B and C - A = activity, B = bone, C = cancer
○ UVA debate
○ UVB essential for chelonians, lizards other than geckos, crocodiles
§ Most snakes don’t need it
How long fast ferrets, budgie, large parrots and small parrots
Ferret - 4-6 hours Budgie -> fast for 1 hour Patient preparation - Fast large parrots 2-4 hours - Fast small parrots 1 hour
Anaesthesia for parrots - premed, anaglesia, induction/maintenance and bpm
PM - midazolam
analgesia - butorphanol
induction/maintenance - isoflurane
ventilation - 30-40bpm
Reptiles what use in for premed, induction and maintenance
PM - opioids +/- ketamine +/- alpha-2
Induction - propofol/alfaxalone
IPPV - 2-4 breaths/min
What are the 8 common classes of antibiotics in vet medicine and which do what bacteria
- Penicillins
- Cephalosporins
- Macrolides
1-3 gram positive - Aminoglycosides - NARROW GRAM NEGATIVE
- Tetracyclines
- Sulfonamides
- Fluoroquinolones
- Metronidazole
5-8 - broad spectrum
Pencillins what are the 4 different types and there spectrum/beta lactamse resistance
1) Pencillin G - Gram positive but beta-lactamase sensitive
2) Amoxycillin - gram positive and negative but beta-lactamase sensitive
3) Cloxacillin - gram positive and beta-lactamase resistant
4) Clavulanic acid -> BOTH gram positive and negative AND breaks down beta-lactamase so resistant
- WHY PRESENT
Aminoglycosides what end in, 4 examples, spectrum of activity, side effects and important info
- The opposite of the macrolides, but still end in –mycin
- Neomycin, Streptomycin, Gentamycin, Tulathromycin –large animals mostly
- Gram –ve and Staphylococcus (not streps) - only narrow gram negative
- Nephrotoxicity, and residues in kidneys - not used in small and not really in large animals
- Streptomycin and Gentamycin BANNED in food producing animals
- Must not use gentamycin unless specifically indicated
Metronidazole what used for
- Anaerobic infections
- Particularly mouths, osteomyelitis, peritonitis
In terms of antibimicrobial resistance what are the 3 levels of use and examples within
1) High - essential for humans infections EG - 3rd gen cephalosporins and fluroquinolones
2) Medium - other alternatives but less available EG - cloxacillin, clavulox, 1st gen cephalsporins
3) Low - reasonable alternatives EG - penicillins, tetracycline, neomycin, erythromycin
What are the 2 things that influence the rate of sound attenuation
- Distance -> greater distance, greater depth = more attenuation
- Frequency -> higher frequency = more attenuation
Acoustic impedance mismatch what is it and what are the 2 main structures involved
- Ultrasound can’t penetrate through bone or lung due to this - use radiograph instead
- Bone: most sound is absorbed so high acoustic impedance -> casts a distal acoustic shadow -> cannot see internal structure of bone
- Lung: most sound is reflected so low acoustic impedance -> bounces between lung and detector -> thinks it’s an echo back -> reverberation artefact
Frequency of ultrasound what relate to
Low frequency transducers are used to image deep structures BUT LOW SPATIAL RESOLUTION
Contrast resolution in terms of ultrasound what is it and what are the 2 things its controlled by
ability to display differences in echogenicity (greyness) of objects
1) Controlled by dynamic range
○ Use a low dynamic range for echocardiography
§ Difference between parenchyma and lumen
○ Use high dynamic range for abdominal ultrasound
§ Want to see all the shades of grey
2) Also our ability to perceive the different echogenicity
○ Best seen in low gain setting and in darkened conditions
CT number what is it and example for air and bone
The CT number measures the degree of x-ray attenuation (HU units) within a voxel
Air - very low -1000HU
Bone - very high +1000
MRI sequence what one is most important and for what
T2 weighted sequences - most important
§ Sensitive at detecting increased fluid with oedema, inflammation, neoplasia
What are the 3 main issues with ruminants anaesthesia
1) Saliva -> large volume produced, regurgitation -> potential airway obstruction/aspiration
2) positioning - compression of diaphragm and abdominal vessels
3) Tympany - impaired eructation (gas accumulation in rumen) due to recumbency, sedation, anaesthesia -> respiratory distress and decreased cardiovascular function
What are 6 important ways complications and prevented in small ruminant anaesthesia
- Withholding food and water does not totally preclude regurgitation and aspiration
- Protect airway by intubating the trachea with a cuffed endotracheal tube
- Dorsal recumbency avoided or kept to a minimum
a. Left lateral recumbency better - Use gastric tube and suction during surgery
- Oxygen is administered
- Intermittent positive pressure ventilation performed
small ruminant anaesthesia how long fast and what drug can lead to pulmonary oedema
food withheld for 24 hours, water 8-12 hours
Xylazine - rare
small ruminant PM and induction protocols
1) diazepam IV + ketamine IM,IV
2) acepromazine IM + ketamine IM, IV
3) triple drip - guaiphensen + ketamine + xylazine
Monitoring ruminant anaesthetic what are NOT good indications and what should you monitor
- Rotation of the eye and movement are not useful indicator of anaesthetic depth in small ruminants.
- Heart rate should be within normal values, that is, 80 to 120 beats
- Respiratory rate should be between 20 and 40 breaths/min
For limb IV regional anaesthesia and dehorning what use and important in goats
LIMB - no bupivacaine (toxic intravascularly) - lignocaine only
DEHORNING - Needle placement for desensitising the cornual branches of the zygomaticotemporal (A) and infratrochlear nerve (B) in goats - 2 nerves to the horn not just one
NSAIDS how do they exert their affects and what does this result in and therefore what do we want from NSAID drug
NSAIDS exert their actions via inhibiting COX-1,2 and 3
1. COX-1, physiological -> leukotrienes that protect renal blood flow and gastric mucosa
2. COX-2, inflammation of disease and platelet aggregation
3. COX-3, central pain relief (ie: humans & Paracetamol)
In cats and dogs don’t cross blood-brain barrier - NOT USED
WANT - COX-2 blocked but NOT COX-1
COX-2 selective firocoxib (best)
What are the 4 potential risks with NSAID use and therefore CONTRAINDICATIONS
1) renal toxicity
2) livery toxicity
CONTRA - pre-existing renal and hepatic disease, hypovolameia/dehydrated/shock
3) GIT ulceration
CONTRA - pre-existing GI injury/inflammation
4) prolonged clotting tendancy
CONTRA - impending surgery or bleeding tendancy (von willibrans)
List 8 adverse effects of corticosteroids and which most common
- PU/PD - common
- Thin skin and muscle wastage - long-term
- Prolonged healing times
- Polyphagia and weight gain - common
- Iatrogenic hyper- adrenocorticism - high dose CCS
- Rapid withdrawal can cause Addisonian crisis
- Gastric ulcers - not common
- Osteoporosis - with long term
What are the 3 main types of corticoseroids, examples and what used for
- Short-Acting: Hydrocortisone, Cortisone, Fludrocortisone
○ (<12hrs) often used in topical preparations - Intermediate: Prednisone, Methylprednisolone
○ (12-36hrs) used for allergic disease, chronic inflammation, immune suppression - Long-Acting (36-72 hours): Betamethasone, Dexamethasone, Flumethasone.
○ Depot injection for long duration of action. Used for cats with allergies, parturition induction in cows.
What are the 7 halsted principles during surgery
- Observe strict aseptic technique
- Thorough knowledge of anatomy and technique
- Control haemorrhage meticulously
- Gentle tissue handling
a. Every damaged cell placed additional demands on the body’s recovery mechanisms
b. Appropriate location of incisions and adequate incision length - Preserve blood supply to tissues
a. Anatomy is important - Accurate tissue apposition with minimal tension
- Eliminate dead space
○ Dead space predispose to seroma formation and infection
What is clinical staging for a neoplasm, what system should is generally used
Knowledge of tumour type, grade and stage dictates surgical dose TNM System developed by WHO T = tumour characteristics § T15 = 15cm diameter tumour N = regional lymph node involvement § N0 = no node enlargement § N1 = regional node enlargement § N2 = next node in chain is enlarged M - metastatic involvement § M0 - no metastases § M1 - metastases present
Cryosurgery what happens to the tissue and 2 advantages and disadvantages
- Vascular stasis and cell death results in a slough which will heal via second intention (3-6 weeks)
- Depigmentation occurs - hair grows back white
- Advantages
○ Cheap, can use with sedation
○ Can repeat therapy if required - Disadvantages
○ No tissue diagnosis if no pre-treatment biopsy
Lack of ability to assess tissue margins
What are 4 important chemotherapy general principles
1) fewer cells = more likely to be effective
2) multiple doses -> not all cells equally sensitive at all times, recommend 6 cycles
3) multiple drugs - difference mechanism of action less cross resistance
4) chemoresistance is likely to result in treatment failure - MDR1/ABCB1/P-glycoprotein results in multi-drug resistant phenotype -> hyperfunctional pump out drugs, IF NOT SICK DONT GIVE STEROIDS
Bradycardia what level in dog and cat, causes and treatment
HR < 50-70 bpm (dog and) <100 bpm (cat) Causes ○ CNS depression § Anaesthetic drugs, hypothermia, increased intracranial pressure ○ Cardiovascular failure § Hyperkalaemia, hypoxemia ○ Vagal reflex § Pressure on eye, viscera, stimulation of pharnyx/larynx Treatment ○ Determine cause and treat ○ Drugs - doesn't work if hypothermic Anticholinergic (glycopyrrolate or atropine)
Hypercapnia during monitoring patient during anaesthesia what level leads to what, 3 causes and 3 treatment options
- Hypoventilation leading to hypercapnia (CO2 >60mmHg) ○ Low pH ○ Decreased oxygenation - Aponea if untreated will lead to hypoxia and cardiac arrest - 3 Main causes 1. Hypoventilation 2. rebreathing of CO2 3. increased production TREATMENT ○ Provide IPPV or mechanical ventilation ○ Reassess depth of anaesthesia ○ Try to correct the cause
