Master Set - Clinical Skills

Who does radiation put most at risk?

Under 18s and pregnant people

4 radiation safety policies

• controlled area must be used

• PPE must be worn is there is no lead shield

• Reduce scatter - collimation and grid

• Few people involved as possible

Describe positioning for right Lateral Thorax

• Right lateral recumbency.

• Forelimbs extended and secured cranially. Hindlimbs can be extended and secured caudally.

• A foam wedge can be placed under the sternum and in between the limbs to counteract natural rotation.

• Head and neck gently extended

Describe positioning for left Lateral Thorax

• Left lateral recumbency.

• Forelimbs extended and secured cranially. Hindlimbs can be extended and secured caudally.

• A foam wedge can be placed under the sternum and in between the limbs to counteract natural rotation.

• Head and neck gently extended.

Describe positioning for Ventrodorsal thorax

• Dorsal recumbency

• Forelimbs extended and secured cranially

• Hindlimbs can assumed natural position

• Use a trough, sandbags or foam wedges either side of thorax (take care to ensure the edges of the trough or sandbags are not going to obscure your radiographic view) to allow superimposition of sternum

Describe positioning for Dorsoventral thorax

• Sternal recumbency.

• Forelimbs extended and secured cranially.

• Hindlimbs flexed in natural position.

• Ensure spine and sternum superimposed to avoid rotation.

• Head and neck gently extended, chin placed on a small foam wedge and secured with sandbag over neck (care this is not obscuring key anatomy in the image)

Describe positioning for right Lateral Abdomen

• Right lateral recumbency.

• Forelimbs can be extended and secured cranially, hindlimbs are extended and secured caudally.

• Foam pad can be used under sternum and in between stifles/femurs/elbows/radius and ulna to ensure horizontal alignment and no rotation

Describe positioning for left Lateral Abdomen

• Left lateral recumbency.

• Forelimbs can be extended and secured cranially, hindlimbs are extended and secured caudally.

• Foam pad can be used under sternum and in between stifles/femurs/elbows/radius and ulna to ensure horizontal alignment and no rotation.

Describe positioning for Ventrodorsal Abdomen

• Dorsal recumbency, supported by a trough or sandbags at the level of the thorax as necessary to achieve superimposition of sternebrae and vertebrae, avoiding axial rotation.

• Hindlimbs allowed to fall into natural 'frog legged' position or secured in extension with sandbags or ties.

• Forelimbs extended and secured with sandbags or ties.

Describe positioning for Dorsoventral Abdomen

• Sternal recumbency.

• Forelimbs slightly abducted and flexed to stabilise thorax.

• Trough or sandbags might be necessary at thorax to prevent axial rotation and to achieve superimposition of sternebrae and vertebrae.

• If possible hindlimbs are drawn slightly caudally and laterally away from abdomen, held in position with sandbags.

Describe positioning for Mediolateral Elbow

• Lateral recumbency on side of the leg of interest e.g. left lateral recumbency if the left elbow is to be radiographed.

• The other forelimb should be retracted away from the area of interest and secured.

• Neutral view- joint should be flexed to around 90-100 degrees/left in natural position.

Describe positioning for Craniocaudal Elbow

• Sternal recumbency.

• Leg of interest extended.

• Olecranon aligned with humerus ensures no rotation of the joint, foam wedges placed under contralateral axilla can help with this.

• Palpate medial and lateral epicondyles to help ensure they are parallel to plate.

• Head and neck should be flexed away from the limb of interest, this can be achieved with sandbag over the neck or foam wedge next to the head

Describe positioning for Mediolateral Stifle

• Lateral recumbency on side of the leg of interest e.g. left lateral recumbency if the left stifle is to be radiographed.

• The other hindlimb should be retracted away from the limb of interest (Abducted) and secured with a sandbag or tie.

• The stifle should be in a neutral position(not over flexed or extended).

• The tarsus can be supported with a foam wedge underneath to ensure alignment of the limb.

• Care to ensure prepuce and tail are not overlying the stifle.

Describe positioning for Caudocranial Stifle

• Sternal recumbency.

• Sandbags can be used around the thorax to prevent tilting of the body and therefore axial rotation of the stifle.

• The leg of interest is extended caudally with the stifle slightly rotated inwards and secured with a sandbag over the tarsus.

• The contralateral limb is flexed and elevated and placed on a foam pad.

• A foam pad can also be placed under the caudal abdomen on the contralateral side to assist with stabilisation.

• Ensure the tail is secured away from the image.

Describe the steps to interpret a radiograph

1. identify the species and radiographic view

2. Check labelling

3. Assess the positioning

4. Assess the collimation

5. Assess the exposure

6. Identify developmental faults

7. Identify and other artefacts or faults

8. Describe the normal anatomy visible within the image

9. Survey the entire radiograph in a systematic manner to identify any abnormalities

How to Assess the patient for CPR

ABC

Airway

Breathing

Circulation

How can Airway be assessed

• ensure airway is patent

• Best achieved by endotracheal intubation

How is breathing assessed?

• Watch chest

• Feel for exhaled breath

• If not breathing start CPR

How is circulatuon assessed?

Feel for pulse (femoral artery )

If no pulse start CPR

Cardiac Pump Theory

Ventricles directly compressed

• between sternum and and spine (dorsal recumbancy)

• between ribs (lateral recumbancy)

Blood forced out of the heart to lungs and periphery

Relaxation of ventricles returns blood to heart from lungs and periphery

Thoracic pump theory

Intra-thoracic pressure increased

• compresses the aorta

• collapses the vena cava

• Blood flow out of the thorax

Elastic recoil of the chest

• decreased intra-thoracic pressure

• blood flow from the periphery back into the thorax and lungs

Describe Ventilation

• performed with chest compressions - two people needed

• Endotracheal intubation and intermittent positive pressure ventilation

• 100% Oxygen used, reservoir bag of an anaesthetic breathing circuit

• Can also blow down ET tube

• Exhaled air is 15% Oxygen

• If not intubated, can apply mouth to snout ventilation

Name the anatomy of an instrument from the functional end to the part you hold

• tips

• Jaws

• Hinge

• Shaft/Shank

• Ratchet

• Ring Handles

What is this instrument?

Backhaus towel clamp

What is a towel clamp used for?

• Attach surgical drapes to skin

• Pinpoint tip means blood flow to area is maintained

• Apply tips with the curve downwards

Mayo-Hegar needle holder

Olsen-Hegar needle holder

Gillies needle holder

What sizes do scapel handles come in?

Number 3 - for blade sizes beginning with one

Number 4 - for blade sizes beginning with 2

Mayo scissors

Metzenbaum scissors

Describe Mayo Scissors

• chunky tips and short shank

• used for cutting tough or fibrous tissue

• can be used to cut suture material

Describe Metzenbaum Scissors

• Slim tips and longer shank

• Used for delicate dissection or for sharp cutting of soft tissues

• NOT used for suture material

Adson dressing forceps

Describe dressing forceps

• used to hold gauze, cotton and other material when dressing wounds

• used to remove necrotic tissue or foreign bodies from wounds prior to dressing

Describe tissue forceps

• Used for stabalising or holding tissue during surgical procedures

• Interlocking teeth which allow for secure grip on tissue

• cannot be used on hollow organs due to risk of tissue damage or puncture

Adson Tissue forceps

Treves tissue forceps

Allis tissue forceps

Describe Artery forceps

• used for haemostasis - control of bleeding from a vessel or tissue by occluding blood flow

• various sizes, can be curved or straight

• have a ratchet so they can remain securely in place once closed

Halstead mosquito artery forceps - small to medium vessels

Spencer Wells artery forceps - small to medium vessels

Rochester Pean artery forceps - large vessels

Spay hook

Describe Spay hook

• used to help locate and exteriorise the uterine horns during a spay

• anything lifted using these should be checked carefully and identified correctly before ligating or cutting

Describe the square knot

• Secure knot, using two throws

• Can be used in most situations

• if tissues you are ligating are under tension, can cause first throw to loosen before the second throw is placed resulting in a loose ligature so surgeons knot should be considered

Describe grooved director

• guide probes and scalpels to prevent accidental damage to underlying tissues

Describe Surgeons knot

• Secure knot using two throws - first is performed using a double throw, then a single throw on top.

• Asymmetrical so not as secure as square knot

• double throw creates more friction so first throw is more likely to remain tight while second throw is placed

Square knot

Surgeons Knot

What is the difference between a granny knot and a square knot?

3 Routes of Administration

Topical

Enteral

Parenteral

Describe Topical Administration

• Applied to a particular site

  • Epi-cutaneous

  • Inhalation

  • Enema

Describe Enteral Administration

• Administration via the gastrointestinal tract

  • Oral/Gastric

  • Rectal

Describe Parenteral Administration

• Sub-cutaneous

• Intra-muscular

• Intra-venous

What do you need to know for enteral medication (including equation)

Weight of Animal (Kg)

Dose rate (usually mg/kg)

Drug concentration (usually mg/tablet)

Number of tablets = [ weight of animal (kg) x dose rate (mg/kg) ] / drug concentration (mg/tablet)

What do you need to know for parenteral medication (including equation)

Weight of Animal (Kg)

Dose rate (usually mg/kg)

Drug concentration (usually mg/ml)

Number of tablets = [ weight of animal (kg) x dose rate (mg/kg) ] / drug concentration (mg/ml)

Considerations for parenteral medication

Administration:

• Solution : soluble substance dissolved in a solvent

• Suspension : insoluble substance suspended in a solvent

  • Insoluble substances settles out over time

  • NEVER via intra venous route

Syringe:

• Appropriate volume

• Volume of syringe must be larger than volume to be injected

• Smaller the syringe, more accurate the dose.

Hypodermic Needles:

• Appropriate gauge

• Appropriate length

6 rights

1. Right patient

2. Right drug

3. Right dose

4. Right route

5. Right time

6. Right frequency

Describe the purpose of aseptic preparation

• environment contains micro-organism the body is normally resistant to by innate immunity

• Skins also harbours commensal bactreria

• Minimise risk of infection

Define Sterilisation

Process of destruction of all forms of microbial life - only inanimate objects can be rendered 100% sterile

Define Antiseptics

Used on living tissue to prevent or reduce the growth or action of pathogenic agents, therefore preventing infection

Define disinfectants

used on inanimate objects such as surgical instruments and surfaces, they aim to destroy most pathogenic organisms

Name three products that are used in hand prep

Chlorhexidine

Povidone iodine

Alcohol based gels

Describe properties of chlorhexidine

• Not inactivated by organic matter

• Reduces bacterial growth

Describe properties of povidone iodine

• inactivated by organic matter

• Longer contact time

• Can cause skin irritation

• Not as effective at preventing bacterial growth

Describe properties of alcohol based gels

• not as effective as other antiseptics

• Shorter contact time required

Name two pieces of equipment used to preserve asepsis other than gloves

Operating mask

Theatre Cap

When is open gloving used?

Minor procedures as arms are exposed and it is only 70-80% sterile

6 rules for surgeon prep

1. Your hands are only 70-80% sterile after hand prep

   (You need gloves!)

2. No jewellery

3. Forearms should not be not covered

   (Short sleeves/role the sleeves up)

4. Scrub forearms

5. Put mask and hat before you start

6. If gloves break get a new pair

Reasons for patient prep and steps taken to reduce infection

• Skin has commensal bacteria

• More hair present so surgical site is clipped (4 hours before for best results)

• May require initial clean with soap bath to reduce gross debris and transient flora

• Surgical preparation of skin - chlorhexidine common

• Different sterile drapes used

Name the two methods of patient prep

Spiral and Crosshatch

Key behavioural considerations - dogs

• Generally used to being handled by humans – tolerance may vary!

• Canine ladder of aggression/communication (www.apbc.org)

• Use body language to assess how the dog is feeling – they are very communicative if you know what you are looking for….

• Be aware though that if these signs have been repeatedly ignored in the past, dogs may elect to go straight to the top of the ladder.

Key behavioural considerations - cats

• Most domestic cats will tolerate handling and examination well, but individual tolerance varies and previous bad experiences often result in defensive behaviour at the vets

• Body language can be useful, but is sometimes more difficult to interpret – low body position, flattened ears and wide pupils indicate stress, and cats who feel threatened may try to make themselves look bigger and will often hiss or swipe

  LESS is more

• Let the cat remain where it feels comfortable if at all possible

• Don’t tip out of cat basket, let them come out in their own time

• Also be aware that the type of basket the cat arrives in has the potential to vastly alter their behaviour, depending on how difficult it is to get them out of it!

• Use gentle neck/cheek stroking (if the cat is receptive to this!)

• Treats can be useful, as can the use of feline facial pheromones and other calming products (Feliway or Pet Remedy diffusers and sprays for example)

• Stop before you reach full on hissing, spitting angry cat stage and consider alternative methods

• NEVER SCRUFF CATS

Key behavioural considerations - horses

• Rarely overtly aggressive but they are big, and they are prey species. Therefore, their usual reaction to something they don’t appreciate is to try to get away from it. 

• They may bite or kick if other avoidance measures don’t work.

• They appreciate calm, quiet but deliberate handling – don’t creep up on them

• Be aware of blind spots (directly in front and behind)

• Use body language – ear position and body posture can tell you a lot about their emotional state!

• Be aware that most horses are used to being approached and handled mainly from the left hand side.

• Take your time - patience and repetition can win round most horses

Key behavioural considerations - cattle

Different breeds/sexes pose different risks: e.g. dairy cow vs beef cow vs bull vs youngstock vs cow with calf at foot!

• Handling should be done as quietly as possible, calm cattle are easier to handle!

• Safe handling of cattle requires appropriate, well-maintained equipment – pens, races, crushes

• Cattle are often best handled and moved as part of a group, where possible

If moving individual animals, be aware that cattle (and sheep) have a ‘point of balance’ which allows us to move animals by stepping in or out of their flight zone (see https://www.grandin.com/behaviour/principles/flight.zone.html for details)

Once safely contained in a suitable environment, a halter can be applied to facilitate head restraint for various procedures

Behavioural considerations - sheep

• Not as large as cattle, and with the exception of rams, probably considerably less dangerous. That said getting hold of an individual animal for examination can be challenging.

•  Some breeds can be very large, and some can be flighty.

• Appropriate handling facilities will facilitate this, and as with cattle try to move and handle quietly and calmly.  Halters can be used once animals are caught

Restraint

Verbal – simple voice commands may facilitate basic examination

Stand, sit, steady, wait etc

Physical – ranging from hands to equipment

Manual – using hands to steady and animal

Collars, leads, haltis, headcollars, halters – used to facilitate control of the head

Muzzles – prevent biting (Various types: Mikki, Baskerville, Tape, Cat)

Towel wraps and cat bags – useful for swaddling cats, and also for head restraint in brachycephalic breeds where muzzling is impossible

Chemical – not part of this skill

Important to be aware of this option. If handling is impossible or dangerous, it is worth considering the use of sedation or other chemical restraint to facilitate safe handling

Normal parturition

Normal parturition has three stages:

• Stage 1 – Onset of uterine contractions/dilation of the cervix

• Stage 2 – Delivery of the foetus

• Stage 3 – Expulsion of foetal membranes

In polytocus species (those which have multiple foetuses) stage 2 + 3 are indistinguishable

Stage 1. Dilation of the cervix

• Time is variable within species and between species

• Longer in primiparous

• Signs:

  • Restless, uneasy, trying to isolate herself, pawing the ground

  • Onset of uterine contractions, cervix dilation, foetal movement (to get into right position) and allantochorion is forced through the canal (water bag, and water bag rupture at the end of stage 1)

Stage 2. Delivery of the foetus

• Rupture of allantochorion (water bag) indicates start of stage 2

• Expulsion of foetus through uterine and abdominal contractions

• Lamb should be out within about one hour after the water bag appears

• Twins are usually delivered within 30 minutes of each other

Stage 3. Expulsion of the placenta

• Placenta (foetal membranes) expelled through action of uterine contractions (PGF2⍺ and oxytocin)

• Placenta retention – serious consequences. Do not forget to check!

• In polytocous species (pig, cat, dog), placenta expelled with or just after each foetus

• In one or two offspring (cattle, sheep, horse), placenta expelled within three hours of birth

When to intervene

• Farmer has tried and failed to deliver foetus

• Foetus abnormally positioned

• If no progress 30-60 minutes after rupture of foetal membranes (in ewes; intervene sooner in horses)

• If polytocous species and more than 30 minutes has elapsed between offspring

• If abnormal discharge

• If prolapse occurs

Postpartum care

• Ensure the lamb has a clear airway and is breathing

• Allow the ewe to smell her lamb as soon as possible

• Check for more lambs

• Check the ewe for any damage

• Check the ewe has milk, and that milk let down is occurring

• Treat the umbilical cord of the lamb

• Ensure the lamb feeds

Longitudinal anterior

Head first

Longitudinal posterior

back legs first

Transverse

Sideways

Dorsal

Spine of foetus in contact with spine of mum

Ventral

Stomach of foetus in contact with spine of mum

Lateral

One of the sides in contact with spine of mum

Extended

Limb out

Flexed

Limb in

Blood smear

• Part of the standard haematology analysis

• All blood samples where blood cells are of interest should have a blood smear performed.

• Best smears are made with fresh blood straight from the animal so must be done in practice before sending to an external lab.

• Easy to do

• Easy to do badly

• Interpretation “in house” is quick and easy

How good is your smear?

Examine your smear

• Start at low power (x10) and scan the smear to check its quality

• Examine the feathered edge to check for platelet clumps and large cells

• Locate the monolayer: the portion of the smear between the feathered edge and body, where cells are evenly distributed with around 0.5 RBC diameter between them.

Red blood cells

• Density

• Colour

  Variation = polychromasia

• Shape

  Variation = poikilocytosis

• Size

  Variation = anisocytosis

Differential WBCC

• Monolayer (Zone of morphology)

• x100 oil immersion or x40

• “Battlement” pattern

  • 10 fields up, one field to right, 10 fields down, one field to right…..

• Count 100 WBCs, noting the type of each, to give a percentage

  • This is NOT an absolute count; just a proportion

Normal ranges for differential WBCC

	Neutrophils %	Lymphocytes %	Monocytes %	Eosinophils %	Basophils %
CAT	45 - 64	27 - 36	0 - 5	0 - 4	0 - 1
DOG	58 - 85	8 - 21	3 - 10	0 - 9	0 - 1
COW	15 - 33	40 - 75	0 - 8	0 - 20	0 - 2
SHEEP	10 - 50	40 - 75	0 - 6	0 - 10	0 - 3
HORSE	52 - 75	21 - 42	0 - 6	0 - 7	0 - 2
PIG	28 - 70	35 - 75	0 - 10	0 - 15	0 - 3

Platelet count

• Count the number of platelets in each of several high-power fields (x100)

• Adequate platelet numbers suggested by:

  • 10-30/hpf for dogs, cats and cattle

  • 6-20/hpf for horses

• WATCH OUT FOR CLUMPS!

Packed cell volume

• Use a capillary tube, a centrifuge and a reader to work out the proportion of red blood cells in the blood = the haematocrit.

  - Expressed as a percentage of blood volume

• Quick, cheap, easy and useful.

• Only need tiny sample of blood.

• Use to monitor patients for changes in haematocrit.