Fundamentals of clinical practice Flashcards
Sepsis
Presence of pathogens
Asepsis
Free from pathogens
What is the preoperative preparation plan for a patient?
Food and water - some kind of starvation
Clipping before surgical day
prior to induction
Once induction has been done
Specific surgical prep
Catheters and cannulas
How can skin be prepped aseptically?
Surgical scrub solution
Different concentrations for different areas of sensitivity
What are the different surgical scrub solutions that can be used?
Chlorhexidine
Povidone iodine
Isopropyl alcohol
What is the concentration required for surgical spirit when used orally for dogs?
Oral 0.1% chlorhexidine dogs
What is the concentration of surgical spirit when in ocular use?
0.2-2% or 1:50 dilution of ocular povidone iodine
What are the different styles for draping a patient?
Plain 4 corner draping
Draping a limb
Fenestrated drapes
Adhesive barrier drapes
Bacterial infection
More than 10^5 bacteria per gram of tissue
What are SSI?
Surgical site infections are infections of the tissues, organs or spaces exposed by surgeons during performance of an invasive procedure
How can SSIs be classified?
Incisional infections
1. superficial (skin and subcut tissue)
2. deep incisional
Organ/space infections
What are the risks with SSIs?
Result in an increased morbidity and mortality in surgical patients
How are surgical wounds classified?
classified by the degree of contamination to help predict the likelihood that infection will develop
- clean
- clean contaminated
- contaminated
- dirty
What are the properties of clean wounds?
Non traumatic, non inflamed operative wounds in which the resp, G, genitourinary and oropharyngeal tracts are not entered
What are the published infection rates for clean wounds?
0-4.4%
What are examples of clean wounds?
Exploratory coeliotomy
Elective neuter
Total hip replacement
What are the properties of clean contaminated wounds?
Operative wounds in which the resp GI urogen tract are entered, but inder controlled conditions without unusual contamination. An otherwise clean wound in which a drain is placed
cleanwound with GI repro or resp involved (drain often used)
What are the examples of clean contaminated wounds?
Bronchoscopy
Cholecystectomy
Enterotomy
What are the published infection rates for clean contaminated wounds?
4.5-9.3%
What are the properties of contaminated wounds?
Open, fresh, accidental wounds
Procedures in which GI contents or infected urine is spilled or a major break in aseptic technique occurs
What are the examples for contaminated wounds?
Cystotomy with spillage of infected urine
Open cardiac massage for CPR
What are the published infection rates for contaminated wounds?
5.8-28.6%
What are the properties of dirty wounds?
Old traumatic wounds with purulent discharge, devitalised tissue or foreign bodies. Procedures in which a viscus is perforated or faecal contamination occurs
Gross infection is present
old, purulent, devitalised, fb, faeces
What are examples of dirty wounds?
Excision or drainage of abscess
Bulla osteotomy for otitis media
Perforated intestinal tract
What is the primary objective of aseptic surgery?
Reducing infections
What host factors play a role in aseptic surgery efficacy?
Age
Physical condition
Nutritional status
Diagnostic procedures
Concurrent metabolic disorders
Current medication
What operating room practice needs to be carried out for success in aseptic surgical techniques?
Principles of aseptic technique
Sterilisation
Disinfection
Anaesthesia
Atraumatic technique
What are the 3 factors that reduce infection risk?
Patient prep (clipping, scrubbing, draping)
Surgeon prep (scrubbing, gowning, gloving, hats and masks)
Theatre behavior (etiquette, talking , flow etc)
What suggests a rational use of antibiotics in surgical treatments?
Surgery exceeding 90 mins
Prosthesis implantation
Patients with existing prostheses undergoing certain surgical procedures
Severly infected or traumatised wounds
Rational selection of antibiotics for prophylactic use
Traumatic surg, long surg, prothesis prescence
What are the characteristics of an ideal suture?
high tensile strength
Easy to use and tie
Uniform tensile strength = finer suture material can be used
Inhibit tissue reactions and wicking
Non toxic
Non carcinogenic
Non allergic
Easily sterilised
Minimal bacterial adhesion
Standardisable characteeristics
Sufficient length of properties
Inexpensive
uniform tensile strength, easy, non toxic or carginogenic, sterilised
Natural suture
Raw materials from naturally occurring sources
Cat gut/ silk
Synthetic suture
Raw material produced in an industrial process
Nylon etc
absorbable suture
Materials that are fully degraded and absorbed by the body once placed
Non absorbable suture
Materials that stay in place for an indefinite period (60 days without changing in anyway
Monofilament vs multifilament suture
Monofilament suture - single filament
Multifilament - multiple strands that are braided to create a thicker thread of the desired diameter
Tensile strength
Breaking strength per unit area
Memory
Tendency to retain original configuration
“chatter” and tissue drag
Lack of smoothness or presence of friction whilst passing through tissue
Tissue reaction with suture material
Tissues respond to the implantation of sutures as they do to other foreign material and can provoke an inflammatory response
Advantages and disadvantages of absorbable suture material
Advantages and disadvantages of non absorbable suture material
What are the consequences of placing suture material and what are the factors
Suture material is foreign body
Tissue reaction
Amount of material
Presence of infection
What factors affect tissue reaction>
Absorption characteristics
Natural or synthetic
Phagocytosis vs hydrolysis
What is the diameter rating for suture materials?
2-0 is bigger than 3-0
0 is bigger then 00=2-0
What is a swaged needle?
Attached to the suture material
What are the issues with eye needles?
Threading the needle causes a double strand of suture material
Multiple uses causes bluntness
Increases tissue trauma
Benefits of swaged needle?
Minimal trauma
Single use
Optimal penetration properties
(more expensive)
What are the main parts of the needle?
The point
The body
The eye or the swage
What is the chord length of a needle?
The tip of the swage to the needle point
What are the different needle curvatures?
Curvature is measured in relation to a circle. Deeper the wound the more curved the needle
What are the different needle points?
Blunt - circular elliptic
Sharp (polygonal)
Compound (tapercut, short cutting point etc)
What is the composition of needles?
Made from stainless alloys
Sufficiently rigid to resist forces applied to them during handling
Sufficiently flexible to bend before breaking
What is meant by ductility?
Needles are flexible and therefore bend before breaking
This is important as it warns the surgeon that the forces placed on the needle are too great
What is the common composition of surgical instruments?
Stainless steel- strong and resistant to corrosion
Chromium plated carbon steel- cheaper but prone to corrosion and pitting
Titanium - light weight and used to handle delicate tissues. Reduced glare from operating light
stainless steel, chromium plated, titanium
What implants may be placed in stainless steel instruments and why?
Tungsten carbide implants which are particularly strong and used as blades or for gripping
Generally have gold handles for identification
tungston carbide makes stronger- identified by gold handle
What is the role of scalpels and what are their properties?
Cutting skin
Baird parker no 3 is the most commonly used blade
Various blades can be used
What are the types of scalpel blades?
No 10 is most commonly used - large convex surface
No 11 = stab incisions into hollow viscera such as bladder or stomach
no 15 = more delicate with smaller convex cutting edge (precise cuts such as urethrostomies)
What scalpel handle is used in large animal practice?
Number 4
When are different scalpel handling techniques used?
Power grip allows for thicker and tougher tissues to be cut
Pencil grip allows for delicate precise use
What are the different scissors used?
When are mayo scissors used
When are metzenbaum scissors used?
When are suture scissors used?
When are iris scissors used?
How should scissors be held?
Scissors held with the thumb in one ring and fourth finger in the other
Index finger is placed over the joint for increased stability
What is reverse grip for scissors?
Scissors held for cutting towards the dominant hand
What are needle holders?
Ringed instrument with a ratchet mechanism allowing the surgical needle to be held by the needle holder
What are the 3 designs of needle holders?
Mayo hegar
Olsen Hegar
Gillie
When are treves rat toothed forceps used?
Heavy duty with a single tooth interdigitating with two on the opposing tip
Can be traumatic to tissues
When are dressing forceps used?
Applying dressings
Have no rat teeth and are particularly traumatic to tissues as pressure is needed if used for this purpose
When are adson rat tooth forceps used?
Fine forceps with a small rat tooth grip
When are debakey forceps used?
LEAST TRAUMATIC These have longitudinal and transverse serrations
originally used for vascular use as they are the least traumatic
What are the grips for thumb forceps?
Penhold or chopstick grip
What are homeostatic forceps?
Designed to occlude blood vessels and prevent haemorrhage
Wide variety all have rings with a ratched mechanism
Straight ot curved and come in variety of sizes with different interdigitations
commonly used = Halsted mosquito, Spencer wells and Carmalt
What are the main tissue holding forceps?
What is the role of retractors?
Varied in their form but can be divided into self retaining and handheld
Improve visibility or exposure for easier and more accurate surgery
placing tissue under tension reduces bleeding and allows easier cutting and dissection
What can be seen in these images?
Left - abdominal retractor (balfour- 3 point retractor which prevents rotation)
Right - thoracic retractor with ratchet mechanism which can gradually retract ribs (2 point retractor)
What can be seen in these images?
What are the main handheld retractors?
What are the 2 main towel clamps?
What is the cascade of events through which wounds heal?
Haemostasis and inflammation (platelet aggregation and WBC)
Proliferation/ Fibroplasia (angiogenesis, granulation)
Maturation (remodelling of collagen 1->3) contraction of the wound
What occurs during haemostasis?
Tissue damage
Blood leakage from vessels
Activation of clotting cascade by damage to endothelium ( intrinsic and extrinsic)
Platelet aggregation and release of cytokines
Stabilisation of platelet plug by fibrin formation
What occurs during the inflammatory phase?
Overlaps with haemostasis
First 72 hours of injury
Vasodilation following transient vasoconstriction
Cytokines in fibrin clot will attract WBCs (neutrophils then macrophages)
Destruction of cells by phagocytosis cleans up bacteria and devitalised tissue
What occurs during proliferation phase?
Overlaps inflammatory phase
Formation of granulation tissue - formed of macrophages, firboblasts and new blood vessels
Fibroblasts proliferate and produce new extracellular matrix, elastin and collagen = strength
More resistant to infection
What occurs in the repair phase of proliferation?
Formation of new epithelial tissue (pale pink tissue)
Shrinking grows across wound
Myofibroblasts cause wound contraction
Contact inhibition- contact of epithelial cells stops growth = smoothness which is normal
Measure wound regularly for deficit shrinking
What occurs during the maturation phase of wound healing?
Remodelling
Type 3 collagen is replaced by type 1 collagen
Cross-linking of collagen
Components of extra cellular matrix change
Increase in tensile strength
Can take weeks to months
What factors affect wound healing?
Patient factors - age and comorbidities
Wound factors - infection and location
Concurrent treatment - corticosteroids(delay healing)
Radiation (tissue fibrosis and vasc scarring)
What patient factors affect wound healing?
Age
Comorbidities (HAC and diabetes)
Nutrition status (hypoproteinaemia- will slow wound healing)
What wound factors affect wound healing?
Infection
Location (tension, movement, local blood supply)
How can concurrent treatment affect wound healing?
Corticosteroids- delay all stages of wound healing
Radiation - Tissue fibrosis and vascular scarring
How can wounds be classified?
Abrasion
Avulsion
Incision
laceration
Puncture
What wound can be seen below?
Abrasion Loss of epidermis and some dermis (blunt trauma/ shearing)
What wound can be seen how does it occur?
Avulsion - tearing of tissues from attachments
on limbs it’s a degloving injury
What wound can be seen and how does it occur?
Incision - created by a sharp object
Minimal trauma (neat)
What wound can be seen and how is it caused?
laceration - tearing type wound causes irregular defect Usually jagged
What wound can be seen and how is it caused?
Puncture
Penetrating wound
Superficial damage may be minimal
Deep damage may be substantial
Outline the skin vascular supply
Epidermis
Dermis
Hypodermis
Subdermal plexus
Terminal branched of direct cutaneous arteries
Within the panniculus and subcutis
protect subdermal plexus in mobilisation
What are the fundamentals of wound management?
Assessment of patient
other injuries
Life threatening complications
Stabilise
Examine with sedation
How to assess type of wound?
Degree of tissue damage
Depth of wound
VItal structures such as bones joints nerves and tendons
(especially important in puncture wounds)
How to assess wound age?
Golden period is 6-8hrs
Contaminated or infected
History from the owner
Has the bacteria started dividing
How to assess level of contamination of a wound?
Foreign material
devitalised tissue
Bacterial innoculum (bit vs clean glass etc)
Takes into account the age and nature of the wound
How does lavage occur for wound management>
Gross contamination- tap water
Copious lactated ringers or hartmanns
35-60 ml18G needle = higher pressure 7-8psi
Debridement - dressings, surgical etc
How can a management plan be created for a wound?
Primary intention closure
Secondary intention healing
Third intention closure
What is meant by golden period in wound healing?
6-12 hrs Bacteria divide
>12hr bacterial invasion
What factors influence bacterial contamination?
Blood supply reduced ability to fight infection
Divitalised tissue ()inc bac growth)
FB (red ability to fight infection)
Type of contamination (soil better than organic debris, clean glass vs bite wound)
Type of bacteria
What are the goals of wound management?
Promote healing
Convert contaminated into clean
Control infection
What are the methods of wound debridement?
Surgical
Mechanical
Autolytic
Enzymatic - rare
Biological- rare
What is the role of wound debridement?
Remove dead necrotic contaminated particulate matter and bacteria from the wound
Ready for wound closure and healing
How is surgical debridement carried out?
debrided with sharp surgery to remove dead tissue
preserve vital structures
can carry out scraping to remove chronic granulation tissue
wound lavage and dressing
How is lavage used as a debridement agent?
Lactated ringers solution due to pH and its compatability with tissue
0.9% saline is often used
Fluid at body temp
35ml with syringe and 18G needle = 7-8psi
high vol on newly presented wounds
What is a wet to dry dressing and how is it used?
Chronic granulation bed to healthy granulation bed
Sterile swabs soaked in isotonic crystalloids such as Hartmanns
Placed on chronic granulation bed
Dry swabs on top of the bed to bandage
Changed every 24 hrs
What is the role of negative pressure wound therapy?
A mechanical pump attached to the wound reduces air pressure drawing off exudate and reducing oedema
How does negative air pressure therapy help with wound healing?
Reduces bacterial colonisation
Promotes granulation tissue development
Increases rate of mitosis
Spurs the migration of epithelial cells within the wound
what is shown in the image?
Topical negative pressure wound therapy
What issues arise with negative pressure wound therapy?
Creating an airtight water tight seal
What can be seen in the image?
Negative pressure wound therapy?
What effect does honey have on wound healing?
Antibacterial effect - reduction of bacteria
Healing stimulating properties
Debriding effect
Antiinflammatory effect
Odour reducing capacity
Reducing in wound pain
What is honeys role as a debriding agent?
Osmotic effect
Low pH
Both help to draw fluid from the wound area
How does honey have antimicrobial effects?
Hydrogen peroxide (glucose oxidase)
Antioxidant (flavinoids)
High sugar content (osmotic effect)
Acidic (pH 3.2-4.5)
Methylglyoxal found in manuka honey (nectar from manuka plant 15+ at least)
What issues arise with using standard table honey?
What is biological debridement?
Medical grade maggots
Hard to keep in wound
Unable to identify healthy tissue from necrotic tissue
What is the ranked list of wound debridement?
Speed to effect and expense to cost
Scraping with scalpel often seen as the best
Wet to dry is second best
Why do we need bandages?
Aid to healing of wound, surgical site
Stabilise wound and prevent disruption to healing process
Prevent self trauma and trauma to wound
Prevent debris entering wound
Migrating bacteria
Helps with local pain relief
Aid clotting and prevent further contamination
What types of wound dressing are available?
Dry sterile swab dressing - normally for wet-dry or dry-dry debridement
Impregnated dressings - coated with petroleum jelly or antibiotics
Semi occlusive dressing- central absorptive core with non stick layer to absorb exudate (post op)
Absorbent dressings - for large exudating wounds
Alginates - naturally occuring fibres from seaweeds- moistened and packed into to encourage wound inflammatory factors (dry out eventually and need to be changed)
What are the roles of topical wound gels and creams?
Alginate gels - encourage new tissue growth on stalled wound
Contact cream- flamazine (siver sulfadine) for burns
Dermasol- antibioitc for small wounds
Aluminium liquid spray- large animals covers wounds for protection
What are the layers of bandaging?
Primary layer - dressing (most important)
Secondary layer - padding material 2 components
Tertiary layer- vet wrap etc
What are the 2 components of the secondary layer of a bandage?
Supportive padding dressing - cotton roll (placed for comfort and absorbs exudate that makes it through the dressing, holds away from clean wound) thick enough to prevent strikethrough
Open weave conforming gauze- allows light pressure to be applied can be absorbent (can cause restriction and compression= discomfort and can cause tissue death)W
What are the properties of the tertiary layer of a bandage?
Protection from the outside environment
More important for limb and paw
Usually cohesive layer so sticks to itself
Adhesive layer can be used - stronger and thicker but don’t stick directly to patient (paws normally)
Why are immobilised bandages used?
Robert jones bandage- multiple species in long bone fractures post op protection
Gutter splints - fractures below the carpus (small dogs and cats)
Plaster of paris on a roll - needs to be wetted and applied over the secondary layer
Fibreglass impregnated with resin-
How is an immobilised bandage applied?
Applied 1 joint above and 1 joint below to immobilise the bone to its maximum splinting stability
What are some complications with poorly applied or cared for bandages?
Swelling - distal limb not included
Tissue necrosis - bandage too tight
Decupital ulcers - over bony prominences
Patient interference due to uncomfortable bandage
How can decupital ulcers be avoided?
Ring dressings over the elbows and hock etc to prevent rubbing of the bandage
It comes with its own issue( removes pressure from bony prominence but can apply pressure to the sides of the wound)
What type of dressing is used for wounds that have chronic granulation and are struggling to heal?
Alginate based dressings - Seaweed stimulates the release of inflammatory factors for wound healign
What should be assessed with wounds in large animals?
Classify the wound
How and why it occurred
What structures are involved
How much contamination of the wound is there?
Clean -> contaminated
Location is key for determining wound healing
How should a wound be assessed in large animals
History, clinical assessment and sedation considerations
Lameness level (suggests catastrophic injury through tendons etc)
Assess gait
What should be considered with sedation?
High blood loss is a contraindication
Regional anaesthesia might be required
What structures are affected
DDflexor tendon
Superficial digital flexor tendon
What structures could be affected?
Brachial plexus
Penetration of the thoracic cavity
What could have been damaged here
Synovial structure (calcaneal bursa) suggest a poor outcome
Would cause lameness
Synovial fluid samples and cellularity can assess inflammation etc
What can be used to assess joint wound damage?
Synovial fluid assessment
Sterile solution into calcaneal bursa allows for indication of bacteria presence in the wound
Imaging of wound for fractures
How can imaging be used in wound managment in large animals?
Bones (sequestrian - bone that acts as foreign body)
Acoustic shadow suggest foreign body
Soft tissue damage
Fractures
How do we determine wound management options?
Superficial or deep
Structures involved joints etc
Closing the wound options
What is meant by primary closure of wounds?
Primary intention healing is when the wound edges are brought and kept together by sutures or staples.
The healing occurs with wound epithelisation and connective tissue deposition.
What should be combatted in primary closure of wounds in large animals?
Tension
Matress suture patterns combats tension
Stents and quills distribute tension over the surface of the skin
Pressure on the skin is then reduced
How is secondary intention healing carried out in large animal wound healing?
WBCs are encouraged to be attracted to the wounds - Several days/ weeks
To speed this up debridement can be carried out (surgically or wet-dry swabs)
Speeds up route to proliferation
What is delayed primary closure of wounds in large animals?
Allow natural debridement of the body
The primary closure after assessmetn for necrotic tissue
Why are drains used in wound healing?
Route for fluid and inflammatory exudate to exit the wound
Speeds up debridement of the wound
What are some drains that can be used in large animals?
Latex penrose drain in two separate incisions at wound bed
Active drains can be used sometimes
What has been used for healing here?
Primary closure
The deep pocket suggested use of Penrose drain to allow exudate to exit
Quils and stents reduce skin tension
Mattress sutures also decrease skin tension
Wound can heal faster due to primary intention wound healing
How can granulation tissue be fixed in large animal wounds?
Granulation tissue and fibroblasts stops epithelial migration
Has little nerve supply but very good blood supply
This tissue can be trimmed back using a scalpel blade below the skin surface for epithelial migration to occur
When might skin grafting be used in wound management of large animals?
Punch grafting - cores of skin are applied
Pinch grafting - small sections of skin can be embedded into granulation tissue
Apply epithelial cells into the centre of the wound so that epithelial granulation can occur
What are the common bandages used in equine practice?
Simple bandage
A figure of 8 bandage
Robert jones bandage
What is the use of a figure of 8 bandage in equine practice?
Covers for carpus and tarsus to go around the hock
avoids pressure points
Properties of the robert jones bandage
Treatment modality
Support
At least 3 layers
What are the different equine bandaging materials?
Protective material
Padding
Conforming
Outer layer
Finishing
What is the role of the 3 conforming layers in a robert jones bandage?
Condense the padding to provide extra support
What is the role of splinting in equids?
Unstable fractures
Unstable tendon injuries
There is a variety of methods ranging from commercially available options and homemade materials
Where would the splint be placed for the 4 regions of damage in this image?
1- alignments of dorsal cortices, splint placed dorsally
2. Splint placed laterally and caudally
3- splint placed laterally and medially
4- forelimb - stabilise carpus
Where would splints be placed for the regions in the image?
1- alignments of dorsal cortices, splint placed dorsally
2. Splint placed laterally and caudally
3- splint placed laterally and medially
What are the 3 phases of bone healing?
Inflammatory
Restorative
Remodelling
What is the overall process for the inflammatory phase of bone healing?
Inflamatory response with fracture
Lysis of osteocytes liberates inflammatory mediators
IMs call in macrophages and inflammatory cells to clear wound and debris
What happens chronologically in the inflammatory phase of bone healing?
The blood clot is formed at the fracture site w/in 2 hrs (blood clot plays a role in neovascularisation)
Phagocytes called to the location
When is compartmental syndrome likely to occur in bone healing?
Inflammatory phase
What occurs in the restorative phase of bone healign
Soft callus formation
Hard callus formation
What occurs in soft callus formation of bone healing?
The first callus is similar to hypercellular fibrocartilaginous tissue
Callus plays a role in stabilisation of the fracture site
Process takes 4 days to 3 weeks
What occurs in hard callus formation of bone healing?
Blood supply is restored by soft callus support
This means cartilage formed can be substituted by bone tissue (endochondral ossification)
this results in the formation of a hard callus
begins 2 weeks after fracture and ends between 6th and 12th week
What occurs in the remodelling phase of bone healing?
Ends of the bones are enveloped by fusiform mass called a callus
Remodelling occurs involving osteoclasts
Slow process that can take years
Describe bone remodelling using the image
What are the two types of healing within the restorative phase of bone healing?
First intention (minimal bone callus formation)
Second intention (most common natural type of healing)
What occurs in first intention bone healing?
Characterised by direct bone formation on the fracture line
Occurs when the fracture is stabilised with a good blood supply and reducible fracture
compression on fracture site
What is Roux law in first intention bone healing ?
Interfragmentary compression
This can be caused by:
- Patients’ weight
- application of osteosynthesis systems that compress the fracture lines
- placement of osteosynthesis systems that redistribute the weight
What healing can be seen in the image?
First intention healing through the use of a dynamic bone plate
Bony formation with minimum formation of callus
How can vets ensure first intention healing of bones occurs?
ensure that the blood supply is not excessively damages (particularly the intraosseous supply)
Ossification by first intention takes place much faster the second intenteion
What are the issues with first intention bone healing?
At first, direct osteonal union is not as stable as primary healing with separation
When does second intention healing occur in fractures?
Late treatment
Deficient reduction of the fracture or loss of fragments
Poor blood supply
Infection
Absence of forces of compression
What bone healing has occured
Within the restorative phase there is poor blood supply, anatomical reduction hasn’t occurred and there are few compressive forces
This means that second intention healing (soft callus formation followed by excessive hard callus formation)
Right xray shows remodelling of hard callus bone
What are the principles of fracture repair
Stabilise animal
Orthogonal radiographs
Fracture score and assess what forces are applied to the fracture and how these can be managed
Make sure expertise and equipment is available
What radiographs should be taken for fracture managment?
Orthogonal radiographs
Mediolateral view and craniocaudal view
How can fractures be assessed?
Fracture scoring gives an indication of severity and biological nature of the fracture as well as non biological factors such as financing and surgeons abilities
Higher score= more demanding to repair and therefore greater chance of complications
What is taken into account with fracture scores?
Patient factors
Fracture
Owner factors
Surgeon
What are the patient factors assessed in fracture scoring?
Weight of animal
Age
Boisterousness
Concurrent illnesses
What are fracture factors assessed in fracture scoring?
Type of fracture - does it allow compression plating or req external fixator
Open or closed
Associated soft tissue injuries
Single or one of several fractures
What owner factors are assessed in fracture scoring?
Will they comply with post op instructions
Finances
What surgeon factors are assessed in fracture scoring?
Are they able to manage the fracture
Is the equipment available
What mechanical factors are assessed in fracture scoring?
Degree of displacement/ comminution
What biological factors are assessed in fracture scoring?
Young dog vs old dog
Soft tissue components
Osteosarcoma = Pathological fracture = wont heal
Contamination if open fracture
What are the normal physiological forces that occur when weight bearing or from muscle contraction on a bone/ fractured bone?
Bending- when leg placed at angle to ground or asymmetrical muscle contraction
Torsion - when body changes direction with leg planted on ground
Tension
Axial compression
What affects the fracture repair treatment?
determined by fracture type and forces that will be applied
What is the effect of axial compression on oblique fracture surfaces?
Shear force will be generated
What physiological forces can be seen in the image?
- axial compression
- tension
- bending
- torsion
What should be assessed with compression on tension aspects of long bones?
Diaphyseal bones are asymmetrically loaded when weight-bearing
mandible is asymmetrically loaded during mastication
Describe the forces that should be assessed and accounted for in fracture management of a long bone?
Asymmetrical forces are applied to the bone and result in internally generated forces
This produces tension or compression
a plate should be applied to the tension side as it will not be broken by tensile forces but would be by successive compressions
What are the tension aspects of the long bones?
Femur- lateral aspect
Tibia- medial aspect
Radius- craniomedial aspect
Humerus - laterocranial aspect
Mandible - dorsal aspect
What are the consequences of different forces acting on a fracture?
Axial compression is good when transverse if not then this will cause the fracture to collapse or shear
Tension causes the fracture to be distracted (lag screwing or tension bands)
Torsion results in rotation of the fracture ( plates or external fixator)
Bending due to asymmetrical nature can be corrected with pin in the medullary cavity
What does primary healing of the bone require?
Intimate contact of the bone ends under compression
Through application of bone plate and extensive dissection and manipulation of soft tissues
What does secondary healing of the bone require?
Doesn’t require reduction of fracture
Adopting look but do not touch approach or minimally invasive plate os (MIPO when a plate is placed through the subcut tunnels)
What effects whether a fracture should be repaired at all?
Strain that tissues will tolerate as the fracture heals
Some fractures naturally have movement
Younger the animal the fracture may only require that the animal be cage rested
Cage rest can cause pressure sores and joint stiffness
What is the strain theory in fracture management?
Strain is the change in length over the original length of the fracture
Small gap and much movement then the strain is high ad the fracture fails to heal as the tissue rupture
What is the % elongation at rupture for fracture management?
How does the formation of a callus in bone healing affect strain?
Resorption of fragment ends increases the fracture gap and therefore creates greater stability and reduced movement at the fracture site and the strain decreases
What can be seen in the image
Plating of a tibial fracture
Accurate reduction of the fracture
Not under compression as the fracture is oblique
No callus should form and there will be bone to bone union
What treatment approach can be seen in the image and what will be the result?
External fixator with a LBDT approach
Results in secondary healing and callus formation
What is the importance of post operative assessments in fracture treatment?
Radiographs are used to assess
- alignment of the fracture
- Positioning of implants
- encroachment of implants into joints or soft tissues or the bridging of growth plates in young animals
When should post-operative radiographs be taken in fracture management?
Prior to the removal of implants
If the progression is not as anticipated
There is evidence of sepsis
What are the fracture treatment options for small animals?
Intramedullary pin and cercalge wire
Plating (w or wo compression
Intramedullary nail
External Fixator
Pin and tension band
Various combinations of these
What are the properties of the intramedullary pin?
Counteracts bending forces as it lies in the centre of the bone
Poor at axial compression
using this pin means that the bone column is reformed with the aid of cerclage wire
What is the role of the cerclage wire in fracture management?
Cerclage wires draw fragments to their normal position and then fix them relying on the circular cross section of the bone to produce stability
Why might a plate be used with a transverse fracture?
if the fracture is transverse then rotation is possible
To prevent this rotation a plate can be used in addition to the pin
How is the IM pin placed normograde?
Normograde
This is when the pin is placed from proximal end of the proximal fragment
Small skin incision is made and pin is seated into the bone. This pin is advanced proximal to the fracture site
The pin is then pushed into the distal fragment
More difficult that retrograde pinning but allows accurate placement of the pin proximally avoiding the sciatic nerve
How is a retrograde IM pin placed?
The pin enters the proximal fragment distally
Leaves the proximal bone fragment and a small wound is made in the skin for the pin to be pushed through
The pin is grasped by the Jacobs chick pulled proximally until it is positioned proximal to the fracture site
Fracture is reduced and pin driven into the distal fragment
What issues are there with retrograde placement of the IM pin?
Pinning in retrograde suffers from loss of control to where the proximal part of the pin lies
In cat this could lead to damage of the sciatic nerve
What can be seen
Normograde placement of an IM pin
What treatment has been used in the image?
IM pin and cerclage wires
What treatment has been used and why?
IM pin and external fixator
The EF prevents rotation as well as offering resistance to axial compression both of which the IM achieves poorly
What are the properties and uses of the intramedullary interlocking nail?
Requires special jigs to ensure the screws enters the nail
Strong and excellent at preventing rotation and bending
Only be used in straight bones (tibia and femur)
Infrequently used in vet med
What can be seen in the image?
Intramedullary interlocking nail
What are the properties of the external fixator?
Series of pins placed through the skin connected to a connecting bar
Pins are attached to the bar with clamps or epoxyresin
Pins may be threaded or the triagulation of pins prevents them pulling out
Very versatile and counteracts all the forces applied to a fracture (esp with IM pin)
Good for open fractures
What can be seen in the image? Wat are the placement options?
External fixator to radioulnar fracture
Placement can be uniplanar, biplanar, unilateral or bilateral
Bilateral are stronger
can be used to augment IM pin fixation
What complications arise with external fixators?
pins prone to infection
Prone to discharge where pins pass through muscle masses
Req freq exams and reap of loose pins
req staging down (removal of pins to change load bearing from fixator to the bone)
What are the properties of plate fixation and when might they be used?
Lots of diff types
Allow for reconstruction of comminuted fractures
Protect against axial and rotational forces
Not as good at preventing bending as they are not positioned along the central axis of the bone- worse when plate is exposed to cyclical loading
Plate fixation methods
What are the differences between locking and non locking plate fixations?
Non locking are older and req plate to adhere to screws by friction - applies to plate and bone
Locking plate there is a thread where the screw engages as well as in the bone - diameters of the screw that engages in the plate is greater than that which engages in bone
Special guides needed for locking
Can be considered a internal external fixator
Locking means limited ability to angle screws
How can plates be classified by function?
Buttress plate = strong central section that bridges comminuted section of fracture
Neutralisation plate allows reconstruction of fracture by taking some of the load
Compression plate compresses the fracture by making use of eccentrically placed screws in an oval screw hole.
How does a compression plate work>
Screw starts its flight at the top of the slope and when tightened it moves down the slop and shifts one fragment towards the fracture therefore compressing it
Using this way means the bone takes all of the load
What plates are being used to treat each fracture?
- Simple transverse fracture repaired with compression plate
- Comminuted but reconstructable fracture repaired with neutralisation plate
- Comminuted fracture treated with buttress plate
How does cyclical loading lead to plate failure?
the trans cortex is incomplete in this image and radius is compounded by the force strain section of the ulna
This results in the plate being exposed to cyclical loading and failure
In the humerus, femur and tibi this bending tendency can be managed with an IM in, a rod plate
What are avulsion or tension fractures?
Special set of fractures that are produced by distractive forces generated internally
As a result they are exposed to distractive forces during healing
larger fragments can be repaired by screw placement and compression by lagging technique
Distractive forces can be converted into compressive using a tension band
What is a lag screw and how are they used?
Allow for compression to be applied to the fracture
The near hole is over drilled to have the same diameter as the thread so it doesnt grip
When the screw is tightened it pulls the far fragment against the near
Used to produce rigid fixation and will counteract the distractive forces
What is the role of the tension band?
Fracture is reduced and then 2 pins are used to fix it in position
A figure 8 of wire is applied opposite to the distractive foce and the two arms are tightened
With the wire tightened and pulling in the opp direction the end result is compressive force applied to the fracture
What should be considered when dealing with avian fractures?
Pneumatised bone with periosteal blood supply needs to be preserved
Avian bone is brittle and prone to splintering
Avian bone heals primarily from the endosteum
Rapid healing
Anatomical abnormalities due to flight adaptation
Fractures involving joint or w/in 10cm = poor prog
IM pins and external fixators used for thin and brittle bones
Describe the treatment
Humeral fracture in a kestrel repaired with an IM pin tied to a uniplanar external fixatory
Clamps are replaced with epoxyresin to reduce the weight of the device
What factors in equine fractures should result in euthanasia?
Comminuted fractures - esp of pastern region
compound fractures of long bone
complete fractures of long bone and proximal long bone
fracture of pelvis where the animal is recumbent
PONY UNDER 300KG - potentially fixable issues
What were Halsteds principles of surgery?
- Gentle tissue handling
- strict asepsis
Haemostasis
preservation of blood supply
no tension on tissues
Good approximation of tissues
Obliteration of dead space
What might influence healing of tissues?
Age
Nutrition
Comorbidities
Medications
Define Exploratory laparotomy
coeliotomy
Performed with the objective of obtaining information that is not available via clinical diagnostic methods
once underlying pathology has been determined the procedure can continue as a therapeutic procedure
How is an exploratory laparotomy performed?
Abdominal cavity is divided into 5 regions
- Cranial abdomen
GI tract
Right paravertebral region
Left paravertebral region
Caudal abdomen
In an exploratory laparotomy what is being assessed in the greater peritoneal cavity?
Peritoneal fluid
to do this
Excision of the falciform ligament
Examination of the righ and paravertebral gutters
What is being assessed in the cranial abdomen for an Exp laparotomy?
Liver
Gall bladder and bile ducts
Hepatic hilus
Epiploic foramen
Spleen
What should be assessed of the GI tract in an Exp lap?
Stomach
Intestinal tract
Pancreas
Regional lymph nodes
What is assessed in the right paravertebral region of an Exp Lap?
Hepatic portal vein
Caudal vena cava
Coelic artery
Hepatic lymph nodes
Right adrenal gland
Right kidney and proximal ureter
Right ovary and uterine horn
What is being assessed in the left paravertebral region in an Explap?
Aorta
Left adrenal gland
Left kindey and proximal ureter
Left ovary and uterine horn
What is being assessed in the caudal abdomen during and Exp Lap?
Bladder and distal ureters
proximal urethra
Prostate gland and ductus deferens
Uterine body and proximal vagina
Regional lymph nodes
What is assessed of the abdominal wall, peritoneal surface and mesenteries in an Exp Lap?
Diaphragm
Oesophageal hiatus
Aortic and caval hiatus
Greater and lesser omentum
Internal inguinal rings
What are the fundamentals of tumour resection?
Make a diagnosis
Grading and staging the condition
- histologic degree of malignancy
- metastatic spread
- paraneoplastic syndrome
Use this to determine how the tumour will behave
What are the roles of oncological surgery?
Prophylactic surgery
Diagnosis and staging
Definitive excision
palliative surgery
Cytoreduction - follow up w chemo
Management of oncological emergencies
Surgery for supportive therapy
Treatment of metastatic disease
What is an example of prophylactic surgery?
Ovariectomy/ ovariohysteractomy and mammary neoplasia
Reduces the risk of mammary neoplasia with and incidence of 0.5% if before neutered before the first oestrus 8% before second and 26% after 2 cycles
No effect after 2.5 years
What surgery may be classed as an oncological emergency?
Bleeding splenic haemangiosarcoma
How are diagnosis and grading of tumours carried out?
Cytology (FNA and impression smear)
Histology
What biopsies can be carried out for histology of a tumour?
core biopsy
Punch biopsy
Incisional biopsy
Excisional biopsy
What is the role of staging in tumour treatment?
Looking for metastatic tumours
What is meant by surgical dose in tumour treatment?
How much surgery
Debulking/cytoreduction
Marginal resection
Wide resection
Radical resection
Label the tumour below
Pseudocapsule
Reactive Zone
Tumour
Skip metastases
Satellite metastases
What is the role of cytoreductive excision?
Leaves macroscopic volumes of tumour. Will recur unless given adjuvant therapy (which is less effective if gross vs microscopic tumour remains)n
What is meant by marginal excision?
local excision
That is, tumour removal with minimal amount of surrounding normal tissue
Can result in microscopic or macroscopic presence of residual tumour
What is the role of wide excision?
Removal of the tumour with complete margins of normal tissue in all directions
Local recurrence is unlikeley
What should be taken into account with wide excision margins for a tumour?
Fascial planes are the best border to a margin (especially over fat)
Deep margins are much more difficult to achieve
What is meant by radical excision?
Removal of an entire anatomical structure or compartment containing the tumour
Local recurrence unlikely
This often applies for sarcomas which can extend along fascial planes rather than through them
What are the layers of the bowel?
Suture holding is most important in the submucosal layer
What is the role of gastrotomy?
Making a hole in the stomach
For the removal of gastric foreign body
Procedure for gastrotomy?
Stay sutures
Sterile swabs
Operate outside of the peritoneal cavity
Closure
Absorbable monofilament and atraumatic needle
3/0 cats
3/0 or 2/0 in dogs
Pattern
Continuous - simple cont- contin invertinfg
Two layer - sub mucosal / mucosal and then seromuscular layer
Omentalise
What is the role of omentalisation?
Improved vascular supply
Improved lymphatic drainage
Rich source of inflammaotry and immunogenic cells (neut, t and b lymphs and macrophages)
Neovascularisation (angiogenic factors
Define omentalisation
Omentalization, the placement of omentum around organs or within cavities to improve vascularization or drainage,
What is intussusception ?
Intussusception (in-tuh-suh-SEP-shun) is a serious condition in which part of the intestine slides into an adjacent part of the intestine. This telescoping action often blocks food or fluid from passing through. Intussusception also cuts off the blood supply to the part of the intestine that’s affected.
Define intussuscipiens
invagination of a proximal portion of intestine (intussusceptum) into a more distal portion (intussuscipiens)
How long does healing of the intestine and bladder take?
14 days post suturing
Wound strength will have reached nearly normal levels
Urinary bladder takes 21-28 days post surgical repair
Whatis dehiscence?
Breakdown of the intestine and the urinary bladder
usually occurs within 72-96 hrs post op
Occurs during the lag phase of healign
during this time all support and strength of the wound comes from the sutures
What checks should be done at the end of an operation?
Integrity of the repair
Check for bleeding
lavage and suction
Count swabs
Change gloves
Change instruments
What are the signs of a post operative complication and how can they be checked?
Wound infection
peritonitis
Uroabdomen
check clinical signs
Radiography
Abd US
Abd Tap
What can be seen in the image?
Enterectomy dehiscence
What can be seen in the image?
Presence of peritoneal fluid
What can be seen in the slide produced via abdominocentesis?
Toxic neutrophils in high numbere
Bacterial presence
What can be seen in the image? Animal has had bladder surgery
Would expect the animal to be hyperkalaemic
Urethrogram is leaking from bladder repair into the peritoneal space
Peritonitis was also present on Exp Lap
How should the linea alba be closed?
External rectal sheath is most important?
reconstruct the original anatomy
Rectus muscle has no wound holding strength
What is the rectus sheath made up of?
External and internal leaf
What is clinical reasoning?
The process by which veterinary surgeons integrate clinical and contextual factors to make decisions about the diagnoses, treatment options and prognoses of their patients
What are the methods of clinical reasoning?
Pattern recognition, illness scripts
Problem based clinical reasoning
Often dual process reasoning used
What are the properties of pattern recognition reasoning?
Pattern - No memory reliance
Fast unconscious and intuitive
Pattern recognition mode or heuristics (experience)
Cognitive biases and emotional influences are sources of error
What are the properties of inductive reasoning?
Relies on working memory
Slow analytical and abstract
Modes are inductive and hypothetico-deductive reasoning
working cognitive overload and knowledge base can be a source of error
What questions should be answered in inductive reasoning?
What is the problem
Which body system is involved and how
Where in the body system is the problem located
What is the lesion
How is a clinical problem defined and refined?
Identify and clarify problems vomiting vs regurgitation
Prioritise the most specific problems
Jaundice vs lethargy
Focus diagnostic or therapeutic plans on these
Don’t forget the other problems
Body system responsible and how is it involved? primary (structural) or secondary (functional)
How can we differentiate between primary or secondary clinical problems?
History and clinical exam
Further testing
Vomiting animal- mass in abdomen or haemotology may show secondary
Knowing between the two saves clients time and money
How is the location of a clinical lesion located?
History and clinical exam
Further testing such as imaging
Endoscopy etc
What is DAMNIT-V?
Degenerative, Anomalous, Metabolic, Neoplastic, Nutritional, Inflammatory, Idiopathic, Toxic, Traumatic, Vascular
What is a sign time graph?
Graphical representation of changes in pathology over time
What are the 2 components of pharmacology?
Pharmacodynamics
Pharmacokinetics
What is pharmacodynamics
The action of the dryg
What does it target and what is the responseW
What is pharmacokinetics
Movement of the drug in the body
Where does it go
Consider therapeutic plasma concentration
What are the aims of pharmacology?
Right drug
Right dose
RIght onset and duration of action
Supervision and surveillance
Modification and refinement
Do no harm
What are the interacting considerations for drug use?
Underlying disease factors
Drug data
Owner needs
Patient factors
Practice
Compliance
What are the different targets for drugs?
Receptors
Ion channels
Structural proteins
Enzymes
Carrier molecules
DNA
What type of drug is shown in this dose curve?
Agonistic drug
What are the 2 types of agonists?
Partial - acts on a receptor and elicits a 50% response or a smaller response
Full agonist- acts on a receptor and elicits a full response
What is meant by potency of agonistic drugs?
The amount of drug req to produce a 50% of its maximal effects ED50
What is meant by efficacy of an agonistic drug?
The maximum therapeutic response that a drug can produce
What is meant by specificity of a drug?
Capacity of a drug to cause a particular action in an population
What is meant by selectivity of a drug>
Relates to the drugs ability to target only a selective population ie cell/tissue/signalling pathway
In preference to others
What is meant by therapeutic index?
What is the action of a non competitive antagonist?
Either bind to a different receptor site or block “post binding” chain of events
Ie act downstream of the receptor
What is the action of a competitive antagonist?
Shifts the agonist dose-response curve to the right in parallel
What is the action of an antagonist on enzymes?
Bind to catalytic site
Inhibits normal reaction therefore decreased production of undesired product
What is the tachyphylaxis?
The effect of a drug can decrease when given continuously or repeatedly
What are the causes of tachyphylaxis?
Change in receptors
Loss of receptor number
Exhaustion of mediators
Increased metabolic degradation of the drug
Physiological adaptation (crosstalk between body systems, one takes over)
Drug transporters (active extrusion of the drug)
Unit conversion for calculating drug doses
What is meant by dose of a drug?
Amount/volume of medication taken at one time
How can we calculate the volume of a drug needed?
What is a 1%w/v solution
1g of powder dissolved in 100ml
Or equivalent
How are dilution factors used?
What is the C1V1 = C2V2 equation?
How are drip rates calculated?
What are the two options of allometric scaling in drug dosing?
Surface area
Metabolic rate
What is the prescribing cascade?
Risk based decision tree
Legal and professional req
Suitable and authorised medicine for the condition and species you are treating
Where there is no suitable drug we are required to move through the drugs that may work to avoid suffering
What is step 2 in drug cascade?
A suitable vet med authorised in NI with import certificate
What is step 3 in drug cascade use?
Veterinary medicine with marketing authorisation valid in GB or NI wide for a diff species or condition
Import certificate required
What is step 4 in the drug cascade use?
Human medicine UK with marketing authorisation or authorised medicine from outside the UK
Medicine for livestock must be approved for food production in the country it is coming from
What is step 5 in the drug cascade?
Extemporaneous preparation
create a product to use for animals - purity and concentration needs be controlled
bought in
This could include mixing drugs
What is step 6 in the drug cascade?
Human medicines authorised outside of the UK
What is the northern Ireland drug cascade?
Dx
Diagnosis
Px
prescription
Tx
Treatment
AE
Adverse event
AR
Adverse reaction
SAR
Suspected adverse reaction
SQP
Suitably qualified problem
RQP
Registered Qualified person
VMD
Veterinary medicines directorate
NOAH
National office of animal health
COPC
RCVS code of professional conduct
CD
Controlled drugs
POM-V
Prescription only medicine veterinary
POM-VPS
Prescription only medicine veterinarian/pharmacist/SQP
NFA-VPS
Non food animals VPS
AVM-GSL
Authorised veterinary medicine general sale list
Define veterinary prescription
What are the 2 classifications of medicines available on veterinary prescription?
POM-V
POM-VPS
POM-V medicines must have a prescription from a veterinary surgeon
Who can prescribe POM-VPS medicine?
RQP
Clinical assessment of the animals does not have to be carried out when prescribing POM-VPS medicines and the animal does not have to be under the RQPs care but the RQP requires sufficient info
How should a prescription be written?
What added points should there be on a prescription?
What are the five schedules of controlled drugs under the misuse of drugs regulations 2001?
What is the validity of CD prescriptions?
CD in schedules 1-4 have a pres validity of up to 28 days
Prescriptions for schedule 5 CDs have a validity of up to 6 months
Single prescriptions with multiple dispenses are not allowed for CDs in Schedules _________ however an instalment prescription can be used if required
Schedules 2 and 3
How are instalment prescriptions written?
When the total quantity of the prescription is to be dispensed in instalments, the written prescription needs to state the dates for the instalments and the amount or quantity to be dispensed
First instalment must be dispensed within the 28 day validity period
When do further instalments need to dispensed in CDs?
for schedule 2,3 and 4 CDs the instalments do not need to be dispensed in the first 28 days
What is the under care guidance for RCVS?
A VS cannot usually have an animal under their care if there has been no physical examination, therfore a VS should not treat an animal or prescribe POM-V medicines via the internet alone
When must a physical examination be carried out before prescribing POM-Vs?
Define clinical assessment
A clinical assessment is any assessment which provides the VS with enough information to diagnose and prescribe safely and effectively
May include a physical examination byt not always
How should prescriptions be noted in clinical records?
Name and amount
dosage
Admin instructions
Any accessory warnings
What are the health and safety aspects of prescribing?
How should Px misuse be reported?
Alteration to an existing prescription or prescription fraud can be reported to the veterinary medicines directorate via
The RCVS considers reporting Px misuse in public interest and in most cases a report to the VMD will be a justified breach of client confidentiality
What is an adverse event?
Any observation in animals whether or not considered to be product-related that is unfavourable and unintended and that occurs after any use of a veterinary medicine
Included are events related to a suspected lack of expected efficacy or noxious reactions in humans after being exposed to a Vet medicien
What are the types of AE?
Lack of expected efficacy
Unexpected AE (event that is not described in SPC)
Serious AE= death or life threatening clinical signs, disability or incapacity, birth defects
Non serious = AE all other adverse reactions of lack of efficacy following treatment w VM are non serious
SLEE
Suspected lack of expected efficacy
Define adverse reaction
A reaction to veterinary medicine which is harmful and unintended and which occurs at doses normally used in animals for the prophylaxis, diagnosis or treatment of disease or to restore, correct or modify a physiological function
When to report an AE?
After using an authorised VM
Following off label use
Using a human product in animals
After using a compounded preparation
Using an imported product
How should AEs be reported?
Record what happened in as much detail as possible
Report the event electronically to the VMD within 15 calendar days
PSUR
Periodic safety update report
What is the Misuse of drugs act 1971
imposing a complete ban on the possession, supply, manufacture, import and export of controlled drugs except as allowed by regulations or by licence from the Secretary of State.
What is the misuse of drugs regulations 2001?
The Misuse of Drugs Regulations 2001 allow for the lawful possession and supply of controlled (illegal) drugs for legitimate purposes. They cover prescribing, administering, safe custody, dispensing, record keeping, destruction and disposal of controlled drugs to prevent diversion for misuse
What are the 5 schedules of CDs?
1 - no current therapeutic use
2- have therapeutic use but are highly addictive (highly restricted)
3- therapeutic use but misuse may lead to moderate or low physical dependence or high psychological dependence (subject to restrictions and Px
4- Therapeutic use but misuse may lead to limited physical dependence or psychological dependence
5- contain small quantities of substances that might cause dependence but potential for abuse is very low
Drug Schedule examples
How are controlled drugs procured?
Details of drugs requested and supplier
RCVS number
How are schedule 2 drugs kept?
Locked cabinet
Recorded register
lock box in the car - secured to vehicle and not left unattended
Some schedule 3 drugs should also be kept in locked cabinet
Who can a prescribe a CD?
How should controlled drugs be disposed of?
Made irretrievable before disposal
Denaturing kits
Soap for tablets
Cat litter
Destruction of schedule 2 drugs should be witnessed by VMR inspector
CDLO
Independence MRCVS
Recorded in CDR
Who regulates prescribing veterinary drugs and why?
How is regulation of veterinary drugs achieved?
Data assessment and authorisation in GB via the VMD or centralised application to the European medicine agency (EMA)
Prescribing dispensing and supply of veterinary medicines
Testing, inspection and investigation
Post-marketing authorisation
What are the drug distribution classifications?
What is a suitably qualified person?
What is POM-V drugs?
Prescription-only medication - vet
Medicined must only be prescribed by a VS following a clinical assessment of the animal or group of animals which must be under their care
What medicines are classed as POM-V
Stict limitation on its use specifice safety reasons
Specialised knowledge for use and application
Narrow safety margin
Government policy to demand control at a high level
What is a POM-VPS
clinical exam is not required
What is NFA- VPS
only for non food animals
limits the effect of endemic diseases
SEAS
medicines for pet species the active ingredient of which has been declared by the secretary of stat as not req veterinary control
Exempt from the requirement for marketing authorisation
These are over the counter medications
Controlled drugs
Specified feed additives
Define prescribing
Any prescription for a veterinary medicinal product issued by a professional person qualified to do so in accordance with applicable national law
How is the supply process of medications checked and ensured?
How are records, storage and disposal of drugs regulated?
What are the determinants of a dosage regimen?
Activity and toxicity
Pharmacokinetics
Clinical factors
Other factors - dosage form, route of administration
What factors of pharmacokinetics should be considered?
Dose - potency and efficacy
Onset - absorption and distribution
Loading dose - Vd
Maintenance dose - clearance
Time to steady state- Half life
What influences dosage?
The potency of the drug - partial agonist vs full agonist
Bioavailability and first-pass metabolism
Absorption- drug needs to cross the membrane
Distribution
Most drugs are lipo_____ to pass the plasma membrane
Lipophilic
What are the factors that affect onset of activity of a drug?
Time to reach the maximum (Tmax)
Route of administration
Chemical structure and formulation - pH of location
Clinical situations
How can orally adminstrated drugs affect the onset of action?
Polypharmacy
Gut content
Splanchnic blood flow
How can clinical situations affect onset of action of a drug?
Pathology
Tissue blood perfusion
Changes in pH
States of shock
What is meant by life of a drug?
Administration
Absorption and distribution
Elimination
What is loading dose?
Enables therapeutic concentrations to be reached sooner
Principally determined by Vd
What is maintenance dose?
Principally determined by clearance
When is steady state achieved?
Within 5 half lives
What is the calculation for loading dose?
How can steady state be maintained?
Ideal situation is constant IV infusion
Increasing dose frequency minimises the peaks and troughs so the drug will approach Css
Owner and patient compliance is reduced with multiple daily dosign
Need for balanced approach and considerations if dose is missed
What are the 2 types of saturation with multiple dosing?
1, Normal kinetics
2, saturation kinetics
What are normal kinetics of multiple dosing drugs?
Plasma concentration increase proportionally with dose
What is saturation kinetics of multiple doseing drugs?
If dose is increased then disproportionate increase in steady-state concentrations
Necessitates smaller dose increments
What is plasma protein binding and how does it afffect drug action?
Bound and free fractions in equilibrium
Only the free drug is active
Free drug can be distributed, metabolised or excreted
saturable binding could lead to non linear relation between dose and free concentration by the effective concentration range is below that at which this would be important in most scenarios
Extensive protein binding slows drug elimination
What factors affect drug absorption?
Related to the drug
- High for lipid-soluble drug
-Low for molecular size
-Decreases for high degree of ionisation
- Formulation can improve absorption
Related to the body
- increases with SA and absorptive surface
pH will affect the extent of ionisation
GI motility (slow =inc fast = dec)
The integrity of absorptive surfaces
Diseases
What factors affect drug distribution?
Inc adipose tissue increases Vd for lipid soluble drugs
High water body content increases vd for water soluble drugs
What factors affect drug metabolism?
What are polymorphisms in relation to drugs and pharmacology?
polymorphic forms of a drug differ in the physicochemical properties like dissolution and solubility, chemical and physical stability, flowability and hygroscopicity.
These forms also differ in various important drug outcomes like drug efficacy, bioavailability, and even toxicity.
What factors affect the excretion of drugs?
How does the neonate and paedriatric patient alter pharmacokinetics?
Absorption is variable as there is altered gastric emptying and rapid topic absorption
Distribution inc for non lipid
Distribution dec for lipid drugs
Metabolism is dec as there is dec hepatic function
Excretion - GFR is normal but drug tubular secretion in the nephron is longer for weak acid or basic drugs
What alterations need to be made to neonate drugs?
Absorption is variable
Plasma level affected therefore alterations to dose and dose frequency
Possible lower metabolic clearance
Possible lower excretion clearance
How does the geriatric patient alter pharmacokinetics?
Absorption reduced
Body mass inc so lower water inc fat content
Metabolism changes are minimal so decreased plasma albumin
Excretion has decreases renal elimination as decreased renal mass and GFR (similar to animals with chronic renal disease)
How should drugs be altered for geriatric patients?
Reduced bioavailability lowers Cmax Later Tmax
Affects plasma level- dose and dosing frequency
Little change in metabolic clearance
Lower excretion clearance
How do pharmacokinetics change for chronic cardiovascular disease?
decreased metnation- inc effects of sedatives
Decreased blood flow = lower clearance for highly cleared drugs eg anaesthetics
How do pharmacokinetics change for renal disease?
Associated with most profound changes in PK
A gradual loss of urine concentrated ability and ability to acidify
Also altered drug distribution patterns
Change in acid base balance
Uraemia - chronic acidosis, red albumin binding of drug and less hepatic metabolism
How do PK change for liver disease?
Content and activity of phase 1/II reactions is decreased
Little effect on drug metabolism untile 80% functional loss
no adequate functional tests
Most antimicrobials are well tolerated
How does PK change for respiratory disease?
Altered serum pH and protein binding
How does disease affect dosing regimen of drugs?
What is the therapeutic index of drugs?
What drugs have a high therapeutic index?
What drugs have a low therapeutic index?
Drugs with a ____ therapeutic index used in chronic therapy may require therapeutic monitoring for altered physiological states
Low
How is therapeutic monitoring of drugs carried out?
What are the routes at which drugs can be eliminated? PK
Urine
feaces
Milk and sweat
Expired air
Pharmacokinetics of a drug
we want drugs to be above the minimal effect concentration but below toxic levels
This window is the therapeutic window a
we want this to stay in the therapeutic window until the issue is resolved
What is the onset of action of a drug?
The time taken for the drug to become effective
What is the Cmax?
The concentration max which is the peak concentration
This needs to be below the toxic levels
What affects drug absorption?
IV bolus = instant
Infusion= zero order
Oral or IM= inc slowly and then decline
What is the termination of action?
When elimination of drug brings concentration below the minimal effective concentration
What is the elimination rate?
The amount of parent drug eliminated from the body per unit of time
How does elimination of a drug occur?
Metabolites then excreted
Direct excretion via the kidneys
Hepatobiliary system
What are the principles of drug metabolism?
Enzymatic conversion of drug to a metabolite
Lipid soluble to water soluble is the aim
Lipid soluble -> catabolic phase-> drug derivative -> Anabolic phase -> Water soluble drug
What is the role of CYP450?
Cytochrome P450 (CYP) is a hemeprotein that plays a key role in the metabolism of drugs and other xenobiotics
Explain drug renal excretion
Passive filtration of small drugs (effected by GFR and plasma protein binding)
Secretion (affinity for transporters, lipophilicity and polarity effect)
Reabsorption (effected by lipophilicity, polarity and urine pH)
If remain in the nephron then excretion via the urine
What transporters are found in the proximal tubule?
OATs and OCTs
If a drug is lipophilic what will be the action in the distal tubule of the kindey?
Lipophilic drugs will be reabsorbed
Drug clearance
Measure the efficiency of drug elimination
The volume of blood/plasma cleared of a parent drug per unit time
How is drug clearance calculated?
Bioavailability?
Measure of extent of absorption from administration site to measurement site
How is the bioavailability of a drug calculated?
Volume of distribution of a drug?
The volume into which a drug appears to be distrubted with a concentration equal to that in the plasma
Vd is a reversible process
What affects Vd of a drug?
The magnitude of Vd for a drug is influenced by its reversible affinity for tissue proteins vs plasma proteins. It is expressed in units of volume per Kg body weight
What is meant by a half life of a drug?
The time taken for the plasma concentration of the drug to halve
what are the potential drug-drug interactions?
Pharmaceutical - interaction prior to administration
Pharmacokinetic - tissue/plasma levels of one drug altered by another one
Pharmacodynamic- action of one drug is altered by another one
Drug - drug interactions
Altered pharmacological response to one drug caused by the presence of a second drug
What are the potential outcomes of drug to drug interactions?
Enhanced, inhibited or has new effects or no change at all
Summation
Potentiation
Synergism
Summation Pk
The combined effect of two drugs produced a result that equals the sum of the individual effects of each agent
Potentiation pK
When a drug on its own does not have an effect but may affect/be affected in combination with another drug
Synergism
Drug combinations produce a therapeutic or toxic effect greater than the sum of each drug’s action
What are the mechanisms of drug interactions? Pharmaceutical?
Physical - incompatibility interaction (binding to plastic or insolubility in some solutions)
Chemical - Stability of drugs is often pH dependent, oxidation and reduction reactions, complex formation , inactivated by certain vehicles
What pharmokinetic drug interactions can occur?
How can pharmacodynamic interactions of drugs occur?
Additive
Synergistic
Negation
Define ADE
Unintended or noxious response to a drug that occurs within a reasonable time frame following administration
What are the types of adverse events?
How is pain caused?
Results form the interplay of facilitatory and inhibitory pathways throughout the peripheral and central nervous systems
What is the role of maladaptive pain?
Represents malfunction of neurological transmission and serves no physiological purposehat
What is the role of Adaptive pain?
Altering behaviour to avoid damage or minimise further damage
How can pain be assessed?
TPR & pain assessment
Treat pain and reassess
What are the 3 different signs of pain?
Clinical
Biochemical
Behavioural
What are the different pain assessment tools?
Physiological measurements
SDS, NRS, VAS
DIVAS
Composite scales
Pain faces
Acute vs Chronic pain
QoL scales
Analgesiometry and accelerometers
Gait analysis
Pressure sensitive walkways
What are the challenges of pain scoring?
Difficult, subjective and other drugs can affect evaluation
Environment and owner can affect the animal
Species variation
Interspecies variation
Domestication, hierarchy, feeding, aggression
The pain scale must reflect or accomodate these differences
What are the steps to creating a pay scale?
Follow an established psychometric approach
Validity is the most fundamental attribute of the questionnaire
Validity in the criteria, content and construct
Utiity - quick and easy to us
What is being assessed in grimace scales?
. Ear Changes : fold, curl and angle forwards or outwards, pointed shape
2. Orbital Tightening: narrowing of the orbital area,partial or complete eye closure orsqueezing
3. Nose/Cheek Flattening: with eventual absence of thecrease between the cheek and whisker pads
4. Whisker Change:move forward away from face
Ear positions
Orbital tightening
Muzzle tension
What is evaluated in cattle for pain?
Head position
How can pain be assessed in pigs?
Ear position (held backwards= pain )
Equine pain scale
Suggested protocol for monitoring dogs on long term NSAIDs
What is Grapiprant?
An new class of piprant NSAID that doesn’t block COX
It works lower down the inflammatory pathway by blocking some activity of specific prostaglandin
What are the properties of local anaesthetics?
Local anaesthetics are amides or esters
Esters hydrolysed by plasma cholinesterases, amides by the liver
Narrow therapeutic index (easy to overdose, care with dosing)
Overdose? Use 20% intralipid IV
Lidocaine can also be given IV as CRI for analgesia (dogs & horses)
Mechanism of action – ionized charged form interacts with Rc
What are the treatment options for dogs and cats with chronic pain?
What is shown?
Preinscional block
What is shown
Intra testicular block
What is shown?
Direct infilitration of the mesovarium ligament (splash block on ovaries also works)
What is shown?
Retro bulbar anaesthesia
What is shown?
Infiltration of LA following enucleation and suture closure
What is shown?
Lumbosacral and sacrococcygeal epidurals
What is shown
Rostral maxillary dental block
Infraorbital
Provides analgesia to soft tissue of rostral maxillaru
What nerves can be seen?
What is shown?
Caudal maxillary
Extra oral
Needle inserted below the cranioventral border of the zygomatic arch, between caudal border of maxilla and cranial border of mandibular ramus
Needle advanced parallel to the plane of the hard palate and 1cm caudal to the lateral canthus of the eye
The needle is advanced until bone is felt, aspirate! ++ risk of venepuncture
What can be seen?
Mandibular block
The (green) inferior alveolar nerve (IAN) is a branch of the mandibular nerve
Individual alveolar nerves branch dorsally through short section of bone to each individual tooth to innervate the tooth structures and adjacent bone
Nerves exit mental foramina to innervate soft tissue of rostral lower lip
What is shown?
Rostral mandibular block
The (green) inferior alveolar nerve (IAN) is a branch of the mandibular nerve
Individual alveolar nerves branch dorsally through short section of bone to each individual tooth to innervate the tooth structures and adjacent bone
Nerves exit mental foramina to innervate soft tissue of rostral lower lip
Bier block in cattle
What is shown and what are the properties?
This technique provides safe, short-term anaesthesia of the extremity.
To perform IVRA or a Bier block, place a catheter distally in an appropriate vein (cephalic or saphenous) in the limb requiring analgesia.
De-sanguinate the limb by placing an Esmarch bandage, and then place a tourniquet proximally and tighten it.
Remove the Esmarch bandage and inject lidocaine into the cannula, remove cannula and prep leg for surgery.
Bier block used in cattle.
What block is shown?
Femoral and sciatic nerve block
PNBs offer and alternative to epidural with reduced risk of urine retentiona and reduced postoperative opoid consumption
What nerves can be seen?
Femoral artery (arrow) and femoral nerve (solid arrow).
What are the common causes of upper airway obstruction?
Loss of pharyngeal muscle tone
Regurgitation or vomiting
Laryngospasm or laryngeal oedema
Example anaesthesia protocol for equine
What is the starting concentration for volatile anaesthetic agent in horses?
What is triple drip anaesthesia?
What is used for PIVA?
Reduces amount of inhalant gas required
Tree of life
What are the causes of ventricular ectopic beats in surgery and how can they be detected?
Ask yourself if it is actually causing a problem with perfusion & oxygen delivery
Commonest causes of ectopic beats
Circulating catecholamines (stress)
Hypoxia or hypercapnia
Hypovolaemia or hypotension
Anaesthetic drugs
Myocardial inflammation or stimulation
Trauma
CHF or HCM
Major organ dz e.g. intracranial dz
Detected via ECG
How is hypotension detected and treated in surgery?
Check equipment (cuff size, cuff position, transducer, patency of cannula, fluid line)
Urine production?? i.e. other crude indicators of output
Commonest causes of hypotension:
Anaesthetic drugs
Hypovolaemia and haemorrhage
Cardiac insufficiency
Check patient and attempt to determine cause
Reduce volatile/inhalant agent (TIVA/PIVA)
Increase IVFT (intravenous fluid therapy)
Check urine output if possible
Re-check ABP
Consider use of inotrope (dobutamine)
Consider use of vasopressor (norepinephrine)
feline hypotension treatment
Which species has lower CO2 readings and why?
Cats on non-rebreathing systems (T piece or mini Lack)
Often lower ET CO2 readings
What can be seen in the image?
Failing ET CO2 values
In this case due to partial airway obstruction but could be Circ failure, hypervent, hypotens. CA
Troubleshooting ventilation with Failing CO2 readings
What can be seen in the image?
Cardiogenic oscillations
Troubleshooting dysphoria
Trouble shooting prolonged recovery?
ASA status chart
Critically important antibiotics
Decision making
When are antibacterials indicated?
Where cytology and or culture is positive
Antimicrobial sensitivity flow chart
Overview for antimicrobial selection
How should we determine concentration of ABs?
AB concentrations
What are the target of actions of antibiotics on bacteria?
What are the Beta lactams?
Penicillins
Cephalosporins
How do ABs inhibit protein synthesis?
Target the ribosome so that proteins cannot be formed
Summary of ribosome binding antibiotics
Other groups of AB targets?
On top of spectrum of ABs what are the other categories
Aerobic or anaerobic drugs
What are the considerations for effect of ABs?
Groups of antibiotics and relative activities
How are the clinical break points interpreted?
Break point is determined and then anything above is resistant and everything below is sensitive
What is being shown about resistance in the image? AB
Above MIC the resistant bacteria will be left and
Below the MIC the sensitive bacteria will survive but grow slowly while resistant bacteria will proliferate quickly and overgrow
Acquired resistances
Mutation and modification of targets for ABs
Common resistance mechanisms to ABs
What is meant by good antibiotic stewardship?
Relative resistance to disinfection
What are the groups of disinfectants?
Alcohols
Alkalis
Aldehydes
Oxidising agents
Phenols
QACs
Example infection control strategy - faecal oral route
Example infection control strategy- contacts?
Examples of interventions strategies- fomites
Examples of interventiosn strategies - farm facilities
How would we plan an intervention strategy for streptococcus equi?
How would a disinfection strategy be carried out for salmonella?
What is the management and biosecurity for parvovirus?
Summary of disinfectants
What autoclave can be seen?
Vacuum assisted sterilisation system
What is chemical sterilisation and what are its properties?
What is gas sterilisation and what are its properties?
Ethylene oxide in large scale practice (endoscopes etc)
Inactivates DNA cells - strict COSHH controls
Req specialist training and takes a relatively long time without interruption
How are surgical instruments prepared ?
Clean and check
Pack
Sterilise
Monitor sterilisation
Check out of date supplies
What is meant by synergy in ABs?
Where the activity is greater than either of the 2 individually
What is meant by additive effect with ABs?
Where there is a benefit for treatment but there is no increase of individual acitivity
What should be the AB treatment of mastitis?
Sometimes there may be combination treatment but cultures will confirm the need
Class of chemotherapeutic drugs
How can the benefit of chemo drugs be maximised?
How can the harm of chemo drugs be minimised?
What are the objectives of clinical audits?
quality improvement process that seeks to improve patient care and outcomes through systematic review of care against expicit criteria and the implementation of change
Rapid development of resistance to the major anthelmintic classes ?
Current state of anthelminthic resistance
Ectoparasite treatment take-home messages
Which parasite diagnostic test to select?
How can we carry out physical identification of the parasite?
Sampling and microscopy for parasites?
How can we use skin scrapings to monitor treatment for demodicosis?
Parasite ID?
Chewing lice?
Sucking lice
Surface mites
What can be seen in the image?
Top = psoroptes jpinted pedicel and funnel shaped sucker
Other surface mites= unjointed pedical and cup shape sucker
Burrowing mites?
Lens opacity post mortem
Occurs when the carcass is very old or frozen
Reversible on warming
Describe the lesion seen
On the 1. forelimb, there was a clipped area measuring 10 x 5 cm. Within the clipped area is 2. a 3.well-demarcated, 4. focal, 5. pink to dark red, 6. 3 cm in diameter x 2 cm height 7. round, raised, 8. firm, hairless mass.
Describe the lesion
The 1. stomach was 4. diffusely distended, 8. gas-filled and 5. diffusely dark red
Describe the lesion
Affecting 20% of the right kidney, within the renal cortex and extending into the medulla, was a focal, well-demarcated, 3 x 2 cm, light tan to dark red, wedge-shaped lesion.
Describe the lesion
Affecting 30% of the tongue, on the left underside and extending to the lingual surface, there was a focal, moderately well demarcated, pink to red, 5 x 2 x 1 cm, oval, multinodular, firm mass
Describe the lesion
Focally extensively, effacing the perineum and base of the tail, was a well-demarcated, black to red, approximately 1 meter by 50 cm x 10 cm, ulcerated, multinodular mass.
Describe the lesion
Adhered to the viscera and mesentery of the ileum and paired caeca, were numerous, well demarcated, multifocal, up to 2 cm in diameter, pink to tan, round firm masses.
Describe the lesion
Affecting up to 90% of the mammary gland, there was multifocal to coalescing, poorly demarcated areas of grey to light pink, friable tissue, admixed with haemorrhage and abundant light pink purulent exudate (pus).
What causes reversible degeneration that leads to cell injury?
Key points:Depletion of cellular energy stores(adenosine triphosphate ATP)
Cellular swelling / fatty change
Alterations of intracellular organelles
→ In early stages or mild forms of cell injury, the functional and morphologic changes are reversible if the damaging stimulus is removed
What can be seen in the images?
Infarct
Localised area of coagulative necrosis caused by ischaemia due to vascular obstructio
What can be seen?
Pus collection of necrotic neutrophils and tissue debris (encapsulated pus= abscess)
what is caseous necrosis?
What can be seen and why?
Fat necrosis
Focal areas of fat destruction
Fat appears white, firm chalky resembling flecks of soap
Typically resulting from release of pancreatic lipases
What are the types of cell/tissue adaptations and what are there causes?
What is the ability of cells to adapt?
How does pyrexia occur in acute inflammation?
What are the biomarkers of acute inflammation?
Biomarker: a biological molecule that is objectively measured and is an indicator of a normal or abnormal process, or of a condition or disease.
How does transudate occur in acute inflammation?
How does exudate form in acute inflammation?
What can be seen in the image?
Johnes disease
Granulomatous lesions in the lymph node of a johnes cow
What can be seen in the image?
H&E image shows a circular mass of cells caused by a granulomatous lesion
Johnes disease
What can be seen in the image?
Chronic pyelonephritis in a dog’s kidney
Pyogenic granulomas are small raised red bumps
Hydronephrosis
Kidneys have become swollen and stretched
What can be seen in the image?
Actinobacillosis
Bacterial cause.
Rarely be an outbreak of this (an individual cow condition)
Present with increased salivation and difficulty chewing?
Typically acute in its presentation
Proliferative and ulcerative chronic-active inflammatory lesions
Contains neutrophils mixed with mononuclear inflammatory cells (lymphocytes, macrophages, plasma cells).
Fibrous tissue present in the tongue.
What can be seen in the image?
Cross section
Chronic inflammation= loss of muscle of the tongue
Replaced by fibrous tissue during healing
White interwoven bands of fibrous tissue called arrowheads
Granulomatous inflammation in the centre of the image
What can be seen in the image?
Chronic inflammation (mastitis) caused by tuberculosis
Biosecurity
Economic implications
Zoonotic risk
What can be seen in the image?
Immune mediated arteritis
Inflammation occurs in the blood vessels
Swelling of the heart muscle
not often any main clinical signs until severe stage
What can be seen in the image?
Chronic hepatitis
Acute hepatitis = infectious, toxic or idiopathic
Etiology of chronic hepatitis is not known
Acute hepatic failure can progress to chronic active hepatitis.
Clinically, this might be seen as weight loss, lethargy and depression within the animal.
Think about liver disease and impact on protein breakdown (with liver disease, branched chain amino acids are not catbolised correctly)
What can be seen in the image?
Lung pyogranuloma
Granulomas and pyogranulomas in the lung of a dog.
Grey nodules which vary in size throughout the lung parachyma.
nodules would be composed of granulomatous inflammatory
lung lobes would fail to collapse.
What can be seen in the image?
Granulomatous inflammatory lesion
Activated and giant multinucleate cells
Internal intracellular organisms within the giant macrophage cells
Lymphocytes and plasma cells
What can be seen in the image?
Chronic interstitial nephritis
Kidney disorder and inflammation of the kidney.
Acute interstitial nephritis = uncommon in cats
Chronic progressive interstitial nephritis = common and more commonly referred to as chronic kidney disease.
Cause = infectious agents? infectious disease?
What can be seen in the image?
Chronic nephritis in the cat
Granulomatous vasculitis
Development of renal interstitial pyogranuloma.
Multiple, large, irregular, and pale grey subcapsular cortical foci
What can be seen in the image?
chronic interstitial nephritis
Diffuse interstitial fibrosis
Fine pitting of the capsular cortical surface
Stippled red
Bands of greay fibrous tissue surrounding islands of renal cortex
What can be seen in the image?
What can be seen in the image?
Healing bone
Features of benign vs malignant tumours
Cytological features of benign vs malignant tumours
Benign tumour nomenclature
Malignant tumour nomenclature
How does oncogenesis occur?
Starts with mutagenesis or carcinogenesis
These are the initiating factors that cause genetic change
This change makes cells more likely to divide in an uncontrolled way in the right conditions
What is the role of grades in cancer?
How do we follow a definite diagnosis for cancer?
When should tumour biopsy not be carried otu?
What are the different lesion distributions?
What is the distribution of the lesion in this image?
Cranioventral
What is the distribution of the lesion?
Segmental
What is the distribution of the lesion?What
Fibrino suppurative inflammation
What is the morphologic diagnosis of the lesion?
Liver, severe chronic multifocal to coalescing granulomatous hepatitis
What is the morphologic diagnosis of the lesions?
Haired skin, severe, subacute multifocal to coalescing dermal infarctions
What is the morphologic diagnosis of the image?
Brain, sever diffuse acute to subacute suppurative meningitis
What is the morphologic diagnosis of the image?
Heart, severe diffuse subacute fibrino- suppurative pericarditis
What is the morphologic diagnosis of the image?
Lung, cranioventral peracute mild agonal blood inhalation
What is the morphologic diagnosis of the image?
Haired skin, papillomas
Outline the CPR algorithm
BLS = chest compressions and ventilation
How to act as the cardiac pump?
How to act as the thoracic pump?
How to carry out internal cardiac compressions?
Outline the post ROSC care algorithm
Precision and accuracy
What can be seen in the blood smear?
This tissue is from a puppy. What is the morphologic diagnosis?
Small intestine: Enteritis, necrohaemorrhagic, segmental, acute, severe
Is this a lesion? Explain your answer
No this is livor mortis
This tissue is from a dog. What is the morphologic diagnosis?
t is a hemangiosarcoma.
What is an appropriate description for this lesion?
There are multifocal, round, red hairless massess on haired skin.
This is tissue from a cat. What is your morphologic diagnosis?
Left ventricular hypertrophy, diffuse, severes and chronic
This is tissue from a dog. What is your morphologic diagnosis?
Lungs , haemorrhage multifocal to coalescing sever and acute
This is tissue from a Ferret. What is your appropriate lesion description?
severe mucopurulent discharge coming from the eyes and nares.
This is tissue from a cat. What is your morphologic diagnosis?
Cerebrum meningioma
What can be seen in the image?
Pseudomelanosis
This is tissue from a dog. What is your morphologic diagnosis?
mandible and a melanoma.
Can a lesion be seen in the image?
it is not a lesion. What we see is oedema.
What is the morphologic diagnosis of the image?
This is bone, with physis. We see a fracture which is focally extensive, severe and acute.
What is your morphologic diagnosis?
Haired skin, sarcoma
What is the diagnosis for this image?
urinary bladder, there are multiple white gritty crystals.
What is the morphologic diagnosis of this image?
diaphragm. We see a hernia, focal, severe, acute, with visceral displacement.
What is the diagnosis for this image?
duodenum is a focal perforating ulcer with a 1.5cm diameter.
This is tissue from a cat, what is your morphological diagnosis?
haired skin, on the chin of the cat. We see folliculitis which is multifocal, moderate and chronic.
What is the morpholigcal diagnosis of the pathology in the image?
Thryoid, §Adenomatous hyperplasia, bilateral, sever and chroni
This is tissue from a dog, what is your morphological diagnosis?
perianal gland. Here we see an adenoma.
Epithelial cells
High yield, cells associated with one another, rafts, sheets, acini, cuboidal or culmnar
Spindle/ mesenchymal
Low yield, spindle shaped cells, usually single but may be in association/sheets, may be matrix
Round cells
High yield, discrete round cells that are non adherent
What cytology can tell us
Process for masses
What can be seen
Mesenchymal skin tumour
What can be seen?
Lipoma
What are the different types fo round cell tumours?
What can be seen?
Plasmacytoma
Describe and diagnose (dog lymph node)
Lymphoma
x. The smear has poor stain penetration and colour differentiation. The sample is highly cellular consisting of round cells on a pale basophilic background including RBC’s, disrupted cell nuclei and cytoplasmic blebs (lymphoglandular bodies). The rounds cells are lymphoid in appearance (round nuclei with thin rim of cytoplasm). Small lymphocytes are in the minority. Most cells (>50%) are relatively monomorphic large lymphocytes (>2 cell diameters). Poor stain penetration makes nuclear morphology difficult to discern but there may be irregular nuclear borders and conspicuous nucleoli. A disorderly mitotic figure is observed. Rare neutrophils and eosinophils are present.
Describe and diagnose Canine lymph node
Lymph node reactive hyperplasia
The smear has low cellularity on a clear background of occasional RBC’s, disrupted cell nuclei and cytoplasmic blebs (lymphoglandular bodies). The cells are lymphoid in appearance (round nuclei with little or no discernible cytoplasm). There is variation in lymphocyte size but the large majority (>75%) are small lymphocytes with the remainder being intermediate and large lymphocytes.
Describe and diagnose Dog subcutaneous mass
Follicular (epidermal inclusion) cyst
There sample is almost acellular on a background of RBC’s and non-degenerate neutrophils (?iatrogenic sampling haemorrhage). There are ill defined basophilic patches reminiscent of keratin content but not intact squames. A large cholesterol crystal is observed.
Describe and diagnose Dog eyelid mass
Sebaceous adenoma
viii. The smear contains clusters of adherent cells on a clear background with RBC’s. The cells have a roundish monomorphic appearance, eccentric nuclei and abundant foamy cytoplasm. No nuclear atypia nor evidence of inflammation is observed.
Describe and diagnose dog flank skin mass
Follicular (epidermal inclusion) cyst
The smear contains few if any nucleated cells but does have an abundance of anuclear blue staining structures with irregular variably defined angular borders. The morphology is most consistent with keratin/squames. No evidence of inflammation is observed.
Describe and diagnose dog flandk skin mass
Mixed pyogranulomatous inflammation
xii. The smear has low cellularity on a lightly proteinaceous background including RBC’s. The observed cells are a mixture of mostly degenerate neutrophils, non-degenerate neutrophils and vacuolated foamy macrophages with occasional keratin squames. Infectious agents are not observed.
Descrbe and diagnose dog flank skin mass
Mast cell tumour
A moderately cellular sample on a background of RBC’s and scattered metachromatic granules. Nuclear staining is poor. Cells are all of the same round type, in seemingly non-adherent clusters. Pale staining eccentric nuclei are surrounded by intensely metachromatic granular cytoplasm. The nuclear staining quality prevents further evaluation of nuclear characteristics.
Describe and diagnose dog lymph node
Lymphoma
The smear has low cellularity on a lightly staining background with numerous RBC’s, cytoplasmic blebs (lymphoglandular bodies) and disrupted cell nuclei. Occasional neutrophils are observed consistent with the degree of background haemorrhage. The cells are morphologically lymphoid, (round with small amount of cytoplasm). Of the intact cells, the majority are intermediate or large in size. Small lymphocytes are in the minority. Irregular nuclear borders and variably conspicuous nucleoli are observed.
Describe and diagnose dog flank skin mass
Lipoma or subcutaneous adipose
iii. Clusters of swollen, rounded cells with abundant pale/colourless cytoplasm; nuclei are compressed to one edge of the swollen cells
Describe and diagnose dog flank skin mass
Mixed pyogranulomatous inflammation
v. The smear is moderately cellular with a pale staining background including debris, erythrocytes and occasional disrupted cells. Cells include degenerate neutrophils and macrophages with foamy/vacuolated cytoplasm.
Describe and diagnose puppy flank skin mass
cutaneous histiocytoma
The smear contains scattered small groups of medium-sized, round cells with variably small amounts of pale basophilic cytoplasm. Nuclei are round or oval and either centrally or slightly eccentrically placed. There is moderate anisokaryosis (variation in nuclear size). Rare examples of binucleation and nuclear moulding are observed.
Describe and diagnose dog flank skin mass
Sarcoma
vii. The smear is moderately cellular on a haemorrhagic background. There scattered small groups of individual and loosely associated medium-sized, elongated polyhedral or ‘spindle shaped’ cells with indistinct cytoplasmic borders. Nuclei are round or oval; contain single nucleoli and there is moderate anisocytosis (2-3x).
Describe and diagnose prostate FNA
Carcinoma
The sample is highly cellular with a moderately staining background of debris. Inflammatory cells are not a feature. The cellular population is pleomorphic marked anisocytosis, anisokaryosis, and highly variable N:C ratio. There are occasional examples of cellular adherence but in the main, cells are loosely associated. Bi- and multi-nucleate cells are observed
Describe and diagnose Ventral skin mass
Carcinoma
A moderately cellular sample on a variably staining proteinaceous background including debris and occasional RBC’s. Cells are tightly adherent in clusters with often take the form of attempts to create ducts and acini. There is moderately anisocytosis and anisokaryosis and variable but often high N:C ratio. Multinucleation may be present. Inflammatory cells are not a feature.
Describe and diagnose dog skin mass
Neutrophilic inflammation with sepsis
The sample is moderately cellular on a background of variably staining debris and some nuclear disruption and nuclear streaming. The cells are exclusively degenerate neutrophils. Coccoid bacteria are observed commonly in pairs or quartets
