Formative Assessment

Question 1

How long does ACP take to have an effect on the patient and for how long do its effects last?

Answer 1

30-40 mins to effect then

lasts 4-6hrs

Question 2

Why is ACP contraindicated in shocked animals?

Answer 2

It causes vasodilation which leads to hypotension, this can be disastrous in shocked animals leading to cardiovascular collapse

Question 3

Which combination of premedicant drugs is suggested as an appropriate for an ASA category 4 canine patient?

Answer 3

Benzodiazepine and opioid

Question 4

Which category of patients tend to have a higher incidence of concurrent disease and reduced cardiovascular reserve functionality

Answer 4

Geriatrics

Question 5

At what age is a puppy or kitten assumed to have normal liver function?

Answer 5

12 weeks

Question 6

Which class of pre-medicant has a significant drug sparing effect?

Answer 6

Alpha 2 agonists

Question 7

What are the normal expected heart rates in dogs and cats after administration of alpha 2 agonists?

Answer 7

Dog 45-60

Cat 100-115

Question 8

Which pre-medicants can be used for their anti-convulsive effects?

Answer 8

Diazepam

Midazolam

Question 9

Which opioids act on the OP3 receptors?

Answer 9

Morphine, methadone, fentanyl, pethidine

Question 10

How long does buprenorphine take to effect the patient and how long do its effects last?

Answer 10

30-40 mins onset, duration 6 hrs

Question 11

What effects do opioids have on the cardiovascular system?

Answer 11

Cause bradycardia due to vagal stimulation.

Question 12

Explain the aims of using an anticholinergic drug such as atropine (note that this is not part of a standard premedication protocol in modern practice)

Answer 12

Reduce salivary and bronchial secretions

To block the effects of impulses in the vagal
nerves (eg, prevent the oculocardiac reflex)

To block the effects of drugs that stimulate the
parasympathetic nervous system, such as opioids

Question 13

What is the name of the neurotransmitter that is released at the neuromuscular junction?

Answer 13

Acetylcholine

Question 14

Explain the difference in mode of action between depolarizing and non-depolarizing MBAs

Answer 14

Depolarising – occupies ACh receptors causing an initial contraction.

Non-depolarising – there is no initial stimulation

Question 15

Explain the use and potential side effects of suxamethonium

Answer 15

Rapid acting, used in intubation of cats.

Side effects include cardiovascular effects, malignant hyperthermia, increases intra ocular pressure

Question 16

List 2 advantages of using non-depolarising muscle relaxants

Answer 16

They can be topped up

They can be reversed

Question 17

According to the article which 2 non-depolarising MBAs are widely used in practice?

Answer 17

Atracurium

Vercuronium

Question 18

List three types of monitoring equipment suggested for use when monitoring a patient under the influence of NBAs

Answer 18

ECG

BP monitor

Pulse oximeter

Capnography

Question 19

List 3 potential side effects of using a MBA reversal agent such as edrophonium

Answer 19

Increased salivation

Bronchospasm

Bradycardia

Arrhythmias

Question 20

During recovery from a procedure where MBAs are used, how should the animal be positioned to maximise efficient ventilation?

Answer 20

Sternal recumbency for full inflation of the lungs

Question 21

General Anaesthesia - Describe, Advantage & Disadvantage

Answer 21

Anaesthesia may be induced and maintained by injectable or inhalational means.

Intramuscular or intravenous are the most commonly used injectable routes of administering general anaesthesia.

Advantages – convenient, rapid loss of consciousness, facilitates surgical field.

Disadvantages – stressful restraint, technical skill required.

Question 22

Topical Anaesthesia - Describe, Advantage & Disadvantage

Answer 22

Desensitisation is produced only at or near the site of application.

Advantages – little or no cardiovascular depression, inexpensive, easy to do

Disadvantages – used for minor procedures only

Question 23

Local Anaesthesia - Describe, Advantage & Disadvantage

Answer 23

Produces reversible block of nerve impulse conduction.

Advantages – consciousness retained, good for superficial surgery

Disadvantages – used for minor procedures only, possible wound breakdown

Question 24

Explain the effects of anaesthesia on the body in each of the following stages of anaesthesia: Stage I

Answer 24

Pulse increased

resp rate increased

possible breath holding may occur depending on agent used.

Pupils dilate.

Hypereflexia.

Patient may vocalise

Salivate

urinate and defaecate.

Question 25

Explain the effects of anaesthesia on the body in each of the following stages of anaesthesia: Stage III, plane 3

Answer 25

Resp rate decreases Tidal volume is decreased a pause appears between inspiration and expiration, HR and BP decrease Eye position becomes central Pupil diameter increased, Abdo muscles relaxed.

Question 26

Explain the effects of anaesthesia on the body in each of the following stages of anaesthesia: Stage IV

Answer 26

Progressive respiratory failure leading to respiratory arrest. Pulse may be rapid then slows becoming inpalpable. Eye central, pupils dilated and cornea surface dry. Cyanosis turning grey CRT increased

Question 27

ASA Scale I Physical description & patient example

Answer 27

Physical description- Normal healthy patient Patient example- Young dog, elective OVH

Question 28

ASA Scale III Physical description & patient example

Answer 28

Physical description- A patient with moderate to severe systemic disease Patient example- Dog with heart murmur resulting in reduced exercise tolerance

Question 29

ASA Scale IV Physical description & patient example

Answer 29

Physical description- Patient with severe systemic disease that is a constant threat to life Patient example- Dog with cardiac arrhythmia resulting in severe circulatory compromise

Question 30

ASA Scale V Physical description & patient example

Answer 30

Physical description- A moribund patient – not expected to survive without the procedure Patient example- Dog with GDV

Question 31

Explain the purpose of the anaesthetic consent form and describe what is meant by ‘informed owner consent’ (4 marks)

Answer 31

The purpose of the consent form is to record the clients agreement to treatment based on knowledge of what is involved and the likely consequences. The client may be the owner or someone acting with their authority. (No one under the age of 16 should sign the form). Before being asked to sign the client should have the opportunity to read and understand and ask any questions they may have regarding the procedure.

Question 32

A 2 yr old Labrador is booked in for a routine OVH. Describe the pre-anaesthetic assessment procedures (5)

Answer 32

A full clinical history – status of diagnosed chronic disease if applicable, current meds Previous anaesthetic history Temperament of patient, recent changes in food/water consumption Vaccination status Clinical examination – CNS, cardiovascular and respiratory status Pre-op bloods – haematology and biochem

Question 33

A 2 yr old Labrador is booked in for a routine OVH. Describe the aims of premedication (5)

Answer 33

To calm the patient Reduce anxiety Reduce amount of induction agent Reduce amount of maintenance agent Provide analgesia Aid smooth recovery

Question 34

A 2 yr old Labrador is booked in for a routine OVH. Describe the induction procedure of general anaesthetic (intravenous) – include in your answer monitoring procedures immediately post induction (5)

Answer 34

Assist with restraint of patient – i/v catheter in place. i/v induction – restrain and reassure patient. Within 20 seconds induction effective. Assist with endotracheal intubation – connect to anaesthetic machine. Monitor respiration heart rate CRT and temperature closely

Question 35

Describe 2 anaesthetic monitoring techniques used to assess cardiovascular system status (you may include items/equipment in your answer) (2)

Answer 35

Observation – colour of mucous membranes, CRT Palpate pulse- femoral, sublingual, carpal. Auscultate heart. Equipment – Pulse oximeter, oesophageal stethoscope, ECG

Question 36

Explain the procedure you would carry out with a patient in respiratory arrest (6)

Answer 36

Inform VS immediately/summon assistance Turn off anaesthetic vaporiser and flush o2 Patient on 100% O2 Monitor pulse Manual (or automatic) IPPV

Question 37

Explain the procedure you would carry out with a tachycardic patient (4)

Answer 37

Establish cause - inadequate depth of anaesthesia so evaluate in relation to surgery OR may be due to compensatory mechanism/response to hypotension and be critical in preventing hypoxia and hypotension. Liase with surgeon Tachycardia may encourage arrhythmias May require use of drugs to reduce heart rate or increase depth of anaesthesia

Question 38

List 4 emergency drugs that may be used in an anaesthetic emergency and explain the action of each drug (8)

Answer 38

Adrenaline – cardiac stimulant, increases rate and force of myocardial contractions Doxapram – respiratory and CNS stimulant Atipamazole – alpha2 antagonist – used if poor recovery from eg. Medetomidine Atropine- anticholinergic, used to in excess vagal tone, to treat bradycardia Diazepam – benzodiazepine used to treat seizures Frusemide – diuretic, treatment of acute pulmonary oedema

Question 39

List items of equipment that may be used in an anaesthetic emergency (4)

Answer 39

``` Defibrillator Ambu bag I/v catheter Laryngoscope Endotracheal tube Suction machine Oxygen supply ```

Question 40

Describe the monitoring techniques you would carry out for a patients in recovery from post-orthopaedic surgery (5)

Answer 40

vital signs pain levels cranial nerve reflexes observe – i/v fluids, urination, defaecation, record findings

Question 41

Describe the monitoring techniques you would carry out for a patient recovering from respiratory arrest (whilst under general anaesthetic) (5)

Answer 41

constant monitoring of respiration pulse oximetry if possible concentrate on mm colour, cranial nerve reflexes vital signs TPR and record findings

Question 42

List 5 signs an animal should show on smooth recovery from anaesthesia

Answer 42

Return of cranial nerve reflexes – palpebral, jaw tone, swallowing TPR – pulse respiration and body temperature returning to normal ranges No signs of pain

Question 43

Name any 4 premedicants, stating which drug group they belong to , 1 advantage and 1 disadvantage of each drug. (1mark for group, 1 mark for advantage and 1 mark for disadvantage)

Answer 43

Make table

Question 44

Describe the cardiovascular and respiratory effects of propofol post induction

Answer 44

Myocardial depression Vasodilation and bradycardia Respiratory depression, may cause apnoea post induction

Question 45

Describe one advantage and one disadvantage of the inhalational anaesthetic agent sevoflurane

Answer 45

Advantage – non-irritant, more rapid induction and recovery preferred choice for induction by in halaltion method. pleasant odour - well tolerated for mask induction Disadvantage – dose dependent cardiovascular and respiratory depression unstable in presence of soda lime producing compound A which is nephrotoxic in rats

Question 46

Describe one advantage and one disadvantage of the inhalational anaesthetic agent Isoflurane

Answer 46

Advantage – good muscle relaxation good analgesic rapid recovery rapid induction Disadvantage – Hypotension Pungent smell - poorly tolerated for mask induction Potent respiratory depressant irritant to the airways

Question 47

Describe one advantage and one disadvantage of the inhalational anaesthetic agent desflurane

Answer 47

Advantage – lowest blood gas solubility - allowing rapid alterations in anaesthetic depth and fast recovery rapidly excreted via lungs well tolerated for mask induction Disadvantage – requires temperature controlled pressured vapouriser (expensive) irritant to respiratory tract in high concentrations

Question 48

Name 2 muscle relaxants and state for each one whether they are depolarising or non-depolarising (2)

Answer 48

Suxamethonium (depolarising) Atracurium, Vecuronium (non-depolarising)

Question 49

Name 4 opiods

Answer 49

Morphine Pethidine Buprenorphine Butorphanol Methadone

Question 50

Name one steroid anaesthetic

Answer 50

Alfaxalone

Question 51

Describe the correct storage requirements for buprenorphine

Answer 51

stored in locked and permanently secured cabinet – schedule 3 (do not need to keep a register)

Question 52

Describe the correct storage requirements for butorphanol

Answer 52

stored in cool dry place, shelf at room temperature

Question 53

Describe the correct storage requirements for propofol

Answer 53

stored in cool dry place, shelf at room temperature

Question 54

Why might nitrous oxide be administered alongside oxygen as part of an inhalational anaesthetic protocol?

Answer 54

Used to provide analgesia Has an anaesthetic sparing effect meaning lower doses of volatile agents are generally required. It is mixed at a 2:1 ratio with oxygen.

Question 55

Which patients should nitrous oxide be used with caution?

Answer 55

As it accumulates in gas filled spaces it should be used with caution in patients with GDV, intestinal obstruction, pneumothorax, middle ear disease.

Question 56

Explain the term diffusion hypoxia

Answer 56

N2O has low solubility in blood, at the end of anaesthesia when administration of N2O ceases the N2O present in blood diffuses back into the alveoli and ‘dilutes’ the alveolar air so less O2 is available. If the animal is breathing room air hypoxia may occur as a result of this. This effect is mitigated by ensuring that patients receiving N2O have 10 minutes of pure oxygen after cessation of nitrous administration.

Question 57

Explain the term Minimum Alveolar Concentration

Answer 57

MAC is a measure of anaesthetic potency Defined as the quantity of anaesthetic agent required to immobilise 50% of patients when under surgical stimulus. The lower the MAC value the more potent the anaesthetic.

Question 58

Explain the term Blood Gas Solubility

Answer 58

Is a measure of how readily the volatile agent dissolves into plasma. More soluble agents accumulate a reservoir in the blood and slowly move from plasma to the CNS meaning they have a slower onset and recovery time. Agents with low blood gas solubility e.g. sevoflurane are taken up rapidly from plasma = faster onset and recovery.