Module 14 Wk 2 Flashcards
(278 cards)
1
Q
(How to induce and maintain anaesthesia)
What are factors effecting choice of route?
A
- access to vein
- Temperament of animal
- Speed of induction required - IV is fast and IM or inhalation slower
2
Q
What is Co-induction?
A
This is where there is more than one agent. It minimises doses, Cardiovascular effects and benifits sicker animals.
3
Q
How do you maintain Analgesia?
A
- Inhalation
- Injectable anasthesia
4
Q
What agents can supplement anasthesia?
A
- Fentanyl
- Ketamine
- Lidocaine
5
Q
Describe airway management during anesthesia
A
Mask
- Risk leak of gases
- Difficult to hold in place
- Does not protect against aspiration
- Useful very small patients
Supraglottic airway/ laryngeal mask
- Intermediate between mask/ETT
- Sit over larynx, does not enter trachea
- Better seal but not perfect
- Easily dislodged
-Popular in rabbits
- V-gel, anatomically designed
Endotracheal intubation
- Insertion of an endotracheal tube into the trachea
- Orally- most common
- Nasally- usually in horses having dental surgery performed
-Alternatives?
6
Q
What are the benifits to tracheal intubation?
A
- allows a patent airway - relaxation of tissues
- allows the anaesthetist to suppoort ventilation
7
Q
Should you always intubate horses and cats?
A
- It maintain airways well
- But if its a short procedure ist not needed
8
Q
Should you always intubate Dogs?
A
- They are usually easy enough to intubate, you can get some regurgitation.
9
Q
T/F pigs and rabbits are difficult to intubate?
A
True
10
Q
What are risks of intubation?
A
- Laryngospasm
- Trauma/swelling (post-op)
- Endobronchial intubation
- Kinking ETT
- Obstruction with secretions etc
- Obstruction of bevelled end
- Tracheal stenosis (rare)
- Tracheal rupture (rare)
11
Q
(Clinical pharmacology of anaesthetics)
List injectable anaesthetic agents
A
- Propofol
- Steroid anaesthetics- Alfaxalone
- Barbiturates- Thiopentone, pentobarbitone (not licesnced for anaesthesia as it is used as euthanasia med)
- Imidazole derivatives- Etomidate
- Dissociative agents- Ketamine, tiletamine (+ zolazepam = Zoletil)
12
Q
What is the structure, mechanism and formulation of Propofol?
A
STRUCTURE: hindered phenol
MECHANISM: potentiates GABA
FORMULATION: oil-in-water emulsion
13
Q
T/F Propofol is a rapid onset and short duration IV anaesthetic?
A
True hehe
14
Q
Describe the pharmacokinetics of Propofol
A
- Iv administration
- Highly protein bound
- Rapid metabolism in the liver
- It is slower to be metabolised in cats
15
Q
Describe propofol effects in the CNS, CVS, RESP, etc.
A
CNS - Rapid loss of consciousness
CVS - vasodilation and transient fall in BP
RESP - Post-induction apnoea
16
Q
What kind of patients should you use propofol with caution?
A
- Shocked / hypovolaemic patients
- Cats with hepatic dysfunction
- Cats requiring repeat anaesthetics
17
Q
Describe the Structure, Mechanism and Formulation of Alfaxalone?
A
STRUCTURE- Steroid anaesthetic
MECHANISM- Potentiates GABA
FORMULATION - Solubilised in cyclodextrin, not very water soluble
18
Q
T/F Alfaxalone is a slow onset, short duration Injectable ana with a high therapeutic index.
A
False - Rapid onset, short duration injectable anaesthetic with a high therapeutic index
19
Q
Describe the pharmacokinetics of Alfaxalone
A
- IV (IM and SC) routes
- Lower protein binding than propofol
- Recovery initially due to redistribution
- Rapid metabolism by liver in dogs (slower in cats, but they metabolise it more quickly than propofol)
20
Q
Describe the effects alfaxalone has on the CNS, CVS, RESP etc
A
CNS - Rapid loss of consciousness (IV)
CVS - Mild hypotension at clinical doses due to vasodilation
RESP - post-induction apnoea
Recovery can be poor quality esp if limited/poor premed
21
Q
Describe the structure, mechanism and formulation of ketamine
A
STRUCTURE: Injectable dissociative anaesthetic & analgesic
MECHANISM: NMDA receptor antagonist (antagonising an excitatory receptor)
FORMULATION: acidic pH, possible to get water soluble solution
22
Q
Describe the pharmacokinetics of Ketamine
A
- can be given IV,IM or SC
- Rapid hepatic (liver) metabolism
23
Q
Describe the CNS, CVS, RESP and musculoskeletal effects that ketamine has
A
CNS - loss of consciousness, convulsions in dogs/horses, hallucinations.
Musculoskeletal system - increased muscle tone.
CVS - in vitro direct negative inotropic effect, in vivo increased sympathetic tone
RESP - transient apnoea
24
Q
T/F ketamine is a dissociative anaesthesia
A
True
25
What are the advantages and disadvantages of inhalation anaesthetic agents?
Advantages:
- Delivery / elimination depends on ventilation
- Rapid adjustment of anaesthetic depth
Disadvantages:
- Equipment required - Endotracheal tube, carrier gas (oxygen), vaporiser, breathing system etc.
- Environmental pollution
26
What is the most common inhalation seen in practice now adays?
Isoflurane and sevoflurane
27
What is MAC?
Minimum Alveolar Concentration - is the steady-state minimum alveolar concentration of anaesthetic required to prevent gross purposeful movement in response to noxious stimulation, in 50% of test subjects
28
What is the oil:gas partition coefficient?
- Measure of lipid solubility
- If this is high it means there is high potency so low MAC
29
What is the Blood:gas partition coefficient?
- Measure of solubility in blood
- Low blood solubility confers a rapid onset, recovery and rate of change of ana depth
30
T/F Sevoflurane is less potent than Iso therfore you need to give more which means thers more metabolised leading to rapid onset and offset.
true
31
What are the risk factors of Sevoflurane?
- Carbon dioxide absorbents containing strong base
- Long duration of exposure
- Low fresh gas flows
32
T/F agents for mask induction need to have low blood:gas solubility
True
33
(Monitoring the Anaesthetised and Critically Ill Patient)
What four things can you use to monitor the depth of your anaesthetic?
* Eye position
* Jaw tone
* Palpebral Reflex
34
Discuss key factors around the eye while under anaesthesia
Eye rotates ventro-medially
Palpebral reflex abolished
35
If anasthesia is too deep, what might the eye appear like?
Corneal reflex abolished
Eye rotates centrally
Pupils dilates
36
How can resp rate be measured?
- Watching the chest
- Watching the reservoir bag on breathing system
37
What is the normal resp rate for cats and dogs?
8-20 for dogs
15-30 for cats
38
What is the normal pulse rate roughly for dogs and cats?
- Dogs 60-140
- 100-180
39
Why is taking a peripheral pulse important?
It is important as it gives you information about the perfusion of the periphery, if low then means the perfusion isnt good
40
What are two types of respiratory monitors?
- pulse oximetry
- Capnography
41
What are three types of cardiovascular monitors?
- ECG
- Blood pressure
- Capnography
42
Where can a pulse oximeter be placed?
- tongue
- nail bed
- ear tip
- Vulva/prepuce
- Lipfold
43
What are the two different wavelengths of light emitted by a pulse oximeter?
- 660 and 940nm
44
What are the two wavelengths absorbed by?
They are absorbed by differently by oxy- and deoxy- heamoglobin
45
What should the Oxygen saturation be in animals breathing room air?
Above 90%
46
What should the oxygen saturation of an anesthetised animal breathing 100% Oxygen be?
Above 95%
47
Why might the reading on the pulse oximeter be inaccurate?
* Pigmented skin
* Movement (heavy breathing)
* Compression of the vascular bed
* Ambient light
* Poor Contact
* Peripheral vasoconstriction (medetomidine)
* Low blood pressure
* Pulsatile veins (tricuspid regurgitation)
* Abnormal haemoglobins
48
What can cause low Oxygen saturation?
- Low-inspired oxygen
- Lung disease
- R to L shunt
- Hypoventilation
49
Discuss the causes of low oxygen saturation in detail
**Low inspired oxygen**
- Disconnection
- Incorrect gas mixture (100% N2O!)
- Kinked tube
- Airway obstruction
**Lung Disease (V/Q mismatch & Diffusion Impairment)**
- Pneumonia (Aspiration)
- Pneumothorax
- Pulmonary oedema
- Pulmonary embolus
- Bronchoconstriction (Asthma)
**R to L Shunting**
- Congential Heart Disease (Patent ductus, septal defects, tetralogy of fallot)
**Hypoventilation (although not on oxygen supplementation)**
50
What is Cyanosis?
Cyanosis is the blue colouring of arterial blood when deoxyheamoglobin is present.
51
What are the limitations to a pulse oximeter
- Problems with getting reliable readings in some patients
- Doesn’t tell you about perfusion/blood pressure
- Doesn’t tell you anything about CO2 levels
52
What information does a capnography give?
- Resp rate
- CO2 after exhale = EtCo2
- Inspired CO2
53
What does EtCO2 stand for?
End Tidal CO2
54
What is the normal EtCO2 for dogs?
4.6-6kPa
55
In animals with normal lungs what is the EtCO2 an approximation of?
Arterial CO2 partial pressure
56
T/F Hypoventilation increases EtCO2?
True
| So Hyperventilation decreases EtCO2.
57
What does an ECG measure?
It measures the electrical activity of heart giving a continuous measure of heart rate and rhythm.
58
Discuss the adavantages and disadvantages of an ECG
**Advantages**
- Detects arrhythmias
- Useful to identify cardiac rhythm in CPR
- Therefore often indicated in sick patients
**Disadvantages**
- Gives NO indication of adequate cardiac output and hence perfusion to tissues
- Can be normal with severe hypovolaemia or hypoperfusion
- Can even be normal when the heart is not beating!
59
How shall one calculate ones Blood Pressure?
BP = cardiac output x total peripheral resistance
60
What are the normal systolic, mean and diastolic BP in animals?
- Systolic BP >90 mmHg
- Mean BP > 60 mmHg
- Diastolic >40 mmHg
61
What is the gold standard for BP?
Direct BP via cannulation of an artery allowing direct measurment of BP.
62
What are the two indirect techniques to obtain BP?
- Oscillometer
- Doppler
63
What is the normal urine output?
1-2ml/Kg/hr
64
(CPR)
Define Cardiopulmonary arrest?
It is the sudden cessation of functional ventilation and effective circulation.
65
Describe signs of arrest?
* No heart sounds
* ECG shows asystole or arrhythmia
* No palpable pulse
* Apnoea, or jerky gasping breathing
* Blood looks thick, dark and is not flowing freely
* Mucous membrane colour
* Prolonged CRT
* No cranial nerve reflexes
* Eye central with a dilated pupil
* Dry cornea
66
Why might arrest occur?
* Myocardial Hypoxia
* Toxins
* Includes anaesthetics!
* pH extremes
* Electrolyte imbalance e.g. Inc potassium
* Temperature extremes
* hypoxaemia / hypercapnia
* pre-existing cardiac disease
* acute hypotension
* vagal reflexes (e.g. traction on extra-ocular muscles, during enucleation)
Resuscitation
67
FWhats your ABCDE for CPR?
- A = Airway
- B = Breathing
- C = Circulation
- D = Drugs
- E = ECG
- F = Follow-up
68
When assesing the **A**irway what are you looking for and doing?
You want to check for any physical obstruction in the airway and place an ET tube. If this isnt possible then use narrow cathertor or tracheostomy.
69
How many **b**reaths per minute should be administered?
10 (watch chest rise and allow adequate time for deflation)
| so one every 6s
70
What is IPPV?
Invasive Positive Pressure Ventilation
71
When it comes to **C**irculation what is the first thing you should do?
Check for pulses and heart sounds!!
72
When it comes to compressions in small and narrow chested dogs, what position should they be in? Where should you perform compressions?
Right lateral recumbency and compress 3rd-6th intercostal space.
73
What should the rate of compressions be?
100-**120**/min
74
For cats and tiny dogs where should you compress?
Finger and thumbs across heart
| same rate
75
When compressing the 3rd-6th intercostal space in small dogs and narrow chested breeds, what is the pump name?
Cardiac pump
76
Whats is the thoracic pump and who is it designed for?
For large, barrel chested breeds where you compress over the highest point of the thorax.
77
How do compressions via cardiac pump produce output?
Indirect compression of heart
78
How do compressions via thoracic pump produce output?
- chest compression increases intrathoracic pressure
- An increase in intrathoracic pressure leads to pressure on outside of heart, lungs and great vessels
- This causes blood to flow forward in arteries and backwards in veins
- This backward flow is minimised by venous valves/collapse
79
How would you do CPR in bull dogs?
In dorsal recumbancy, compressing over the highest part of the thorax but on their sternum.
80
How do you choose which technique to use for CPR?
- Cardiac: Cats/dogs under 15kg
- Thoracic: Dogs over 15 kg [Except sighthound type build]
- Dorsal recumbency: English bulldog type – DV flattened
81
When is internal cardiac compressions preferred?
* Thorax already open
* Disease processes mean ECC unlikely to be effective (e.g. rib fractures, pleural effusion, diaphragmatic rupture etc)
* If ECC ineffective
* May be suitable to enter via diaphragm
82
What three **D**rugs are commenly used along with CPR? and why?
- Adrenaline - in asystole to coarsen fine ventricular fibrililation, increase inotropy and systemic vascular resistance.
- Atropine - For atrioventricular block, aystole causes by bradycardia.
- Lidocaine - Ventricular arrhythmias.
83
What dose would you give Adrenaline at IV?
0.01mg/kg (IV)
| 0.1 used esp after prolonged CPR - NOT recommended in current guidlines
84
What dose would you give atropine at IV?
0.04mg/kg and only use ONCE
85
What dose would you give lidocaine at IV?
2mg/kg as a bolus but 25-75mg/kg/min infusion.
86
Describe** E**lectrical defibrillation
* Charge
* Apply conducting gel to paddles and dog
* Current applied across heart
!!STAND CLEAR!!
87
How do you work out how much to charge your patient with?
- 2 joules/kg external (4 if monophasic defibrillator)
- 0.1-0.5 joules per/kg if using internal paddles
- Double “dose” for second and subsequent shocks
88
How should you **F**ollow up after CPR?
* Fluids
* Ensure renal perfusion (urine production)
* Warmth (caution)
* Analgesics
* May need other drugs to support (e.g. dopamine)
89
What are signs of effective CPR?
* Palpable pulse during cardiac compression
* Retinal blood flow (as detected by using a Doppler probe on the cornea)
* Carbon dioxide detectable on capnography
* Improvement in colour of mucous membranes
* ECG changes
90
On recovary of CPR, what should you look for?
* Lacrimation
* Pupillary constriction
* Return of cranial nerve reflexes
* Return of other neurological function- e.g. response to sound, righting reflexes etc.
* Return of spontaneous ventilation
91
(Nutritional Support of the Hospitalised Patient)
What are consequences of inadequate nutrition?
- protein- energy malnutrition
- poor tissue repair
- Immune dysfunction
92
When should you intervene with nutritional deficiency?
* Prolonged anorexia (partial or complete) for > 5 days
* Anticipated ongoing inadequate food intake of > 3 days
* Evidence of poor nutritional status
* Concern for the development of hepatic lipidosis
93
What would you base a poor nutritional status on?
- BCS < 3/9
- Hypoalbuminaemia
- Recent weight loss of > 10% of body weight
- Severe generalised muscle wasting
94
What is hepatic lipidosis
Hepatic lipidosis also known as fatty liver is where triglycerides accumulate within the liver cells and obstruct the organ's function.
95
What condition might increase the risk of hepatic lipidosis?
Obesity - ie my cats - colin and diego
96
Why might your patient be anorexic?
- A physical inaability to eat
- An Underlying disease process
- Nausea
- Pain
- Impaired olfaction/taste
97
Name the two appetite Stimulants you would use in practice
- Mirtazepine
- Capromorelin
98
Describe how Mirtazepine works
Mirtazepine is a tetracyclic antidepressent which acts on the 5-HT3 ion channel.
99
Describe how Capromorelin works
Capromorelin acts on they hypothalamus as a ghrelin receptor agonist which increased GH and IGF-1 which stimulates appetiteand leads to weight gain.
100
What are the two types of Assited feeding?
- Entreal Nutrition - nutrition given via GI.
- Parenteral Nutrition - nutrition given IV bypassing GI.
101
What are the 4 tubes used with entreal nutrition?
* Naso-oesophageal/naso-gastric tube
* Oesophagostomy tube
* Gastrostomy tube
* Jejunostomy tube
102
If the patient isnt able to protect their airways how should you provide nutrition?
parenteral Nutrition
103
If the pateint is able to protect their airways but is not fit for GA, what should you do?
- You should place a Naso-oesophageal/naso-gastric tube.
- Or parenteral nutrition
104
If the patient is able to protect airway, is fit for GA but their GI tract isn't functional, what would do?
Parenteral Nutrition
105
If the patient is able to protect airway, is fit for GA, Gi tract is functional but they are vomiting, what would you do?
- Place a Jejunostomy tube
- or a jejunostomy tube through a oesophagostomy tube
- or a jejunostomy tube through a Gastrostomy tube
106
If the patient is able to protect airway, is fit for GA, Gi tract is functional, are not vomiting but they the oesophagus is not funtional , what would you do?
- Place a Gastrostomy tube
- Or a gastrostomy tube through an oesophagostomy tube.
107
If the patient is able to protect airway, is fit for GA, Gi tract is functional, No vomiting, a functional oesophagus, what would you do?
- Oesophagostomy tube
- Naso-oesophageal/naso-gastric tube
108
When it comes to Enteral Nutrition diets what factors is you desicion dependent on?
* Underlying disease process e.g. fat restriction with pancreatitis
* Practicalities e.g. gauge of feeding tube
* Stage of Illness (Acute vs Adaptive stage of illness)
109
What should a critically ill dog or cats daily caloric goal be approx to?
RER (Resting Energy Requirement)
110
How do you calculate Resting Energy Requirement?
RER = (30 x BWkg) + 70 kcal/day
RER = 70 x BWkg0.75 kcal/day
111
For patients that have been anorexic for several days should begin with what RER?
25-50%
112
Re-feeding Syndrome occurs following re introduction of enteral and/or parenteral nutrition. Describe how this might present interms of intracellular shifts?
**Re-introduction of nutrition results in intracellular shifts of K+, PO4- and Mg2+**
- HypoK+ results in profound weakness including myocardial and GI dysfunction
- HypoPO4- can lead to severe haemolysis
- HypoMg2+ may be the cause of refractory hypoK+
113
Re-feeding Syndrome occurs following re introduction of enteral and/or parenteral nutrition. Does this include Carbohydrate intolerance?
Yes
114
Can re-introduction of nutrition cause diarrhoea?
Yes, due to the relatively high osmolarity of liquid diets.
115
What are potential complications of parenteral nutrition?
**Catheter-related **
* Phlebitis
* Thrombosis
* Infection (bacteraemia)
* Mechanical failure of catheters e.g. kinking
**Metabolic**
* Re-feeding syndrome
* Hyperglycaemia
* Hypertriglyceridaemia
* Hyperbilirubinaemia
116
(Getting Gas into the patient)
What two equipment pieces are used to deliver inhaled anaesthetics?
- Anaesthetic machine
- Anaesthetic breathing system
117
What is the purpose of the anaesthetic machine and what are its components?
- It provides a source of 'carrier gas'
- Flowmeter, vapouriser and scavanging system.
118
What is the purpose of the anaesthetic breathing system?
To deliver anaesthetic gaes from the machine to the patient.
119
What are carrier gasses contained in? and where do they attach to the machine?
- Cylinders
- Attach on to the back
120
What did the old O2 gas cylinder look like?
Black with white shoulder
121
What does the new O2 gas cylinder look like?
White
122
T/F the O2 in the gas cylinder is compressed liquid?
False - gas
123
What did the old Nitrous Oxide Cylinder look like?
Solid Blue
124
What does the new Nitrous Oxide cylinder look like?
White with blue shoulder
125
T/F Nitrous oxide cylinders are compressed gas?
False - liquid and gas
126
What do the old Medical air cylinders look like?
Grey with black and white shoulders
127
What do the new Medical air cylinders look like?
White with balck and white shoulders
128
What are some safety features of the cylinders?
- Colour coding of cylinders and pipelines
- Pin-indexing of cylinder yokes and wall sockets.
129
What are flowmeters?
They adjust the amount O2 the patient recieves.
130
Where should you read from if the flowmeter has a bobbin?
The top of the bobbin
131
Where should you read from if the flowmeter has a ball?
The centre of the ball
132
What is the purpose of the vaporizer?
They add anaesthetic vapour to the carrier gas, providing a means of delivering a safe concentration to the patients.
133
How does a Vaporizer work?
* Fresh carrier gas enters and directed into the vaporisation chamber or the bypass channel by a spindle valve
* Gas diverted into the vaporisation chamber passes into close contact with the liquid anaesthetic and becomes saturated with anaesthetic vapour.
* It rejoins fresh gas that has been through the bypass channel before exiting the vaporiser.
* The spindle valve controls the splitting of gas flow between the vaporisation chamber and the bypass channel.
* Diverting a greater proportion of gas flow through the vaporisation chamber will increase the amount of anaesthetic (%) in gas leaving the vaporiser.
134
In the UK what is the max exposure limit of Halothane?
10ppm
135
In the UK what is the max exposure limit of isoflurane?
50ppm
136
In the UK what is the max exposure limit of sevoflurane?
60ppm
137
In the UK what is the max exposure limit of Nitrous Oxide?
100ppm
138
What are the two broad types of scavaging systems?
Passive and active
139
140
What are the two ways of passive scavenging?
* A length of tubing that conducts waste gases out through an open window!
* A length of tubing that conducts waste gases to a canister of activated charcoal
141
What are the downsides of using activated charcoal as a scavanging system?
- It dosent absorb Nitrous Oxide
- Have to weigh regulary to see if still can use
142
What is the plus side to using activated charcoal as a scavanging mechanism?
Its cheap and portable
143
What are the two ways of active scavenging?
* Extractor fan generates negative pressure that draws waste gases from breathing system, venting it outside
* Air break receiver prevents transmission of negative pressure to breathing system
144
What are the pros and cons of the air break reciever as a scavanging mechanism?
- Its Effective for all waste gases
- Its expensive
145
What is the functions of breathing systems?
* Deliver oxygen to patient
* Deliver anaesthetic gas and/or vapour to patient
* Remove exhaled carbon dioxide
* Provide a means to ventilate patient
146
What is tidal volume?
Volume of gas exhaled in 1 breath
147
What should the tidal volume be?
10-20ml/Kg
148
What is the respiritoru minute volume?
It is the volume of gas exhaled in 1 minute
so....
the tidal volume x resp rate
149
What is rebreathing?
Inhalation of previously exhaled gas
150
T/F there is non deteremental rebreathing and then there is detremental re-breathing?
True
- non-detremental rebreathing is when it is rebreathing of exhaled gas which the CO2 has been removed from.
- Detrimental rebreathing is when it is unchanged exhaled gas.
151
What are the two classifications of breathing systems?
- Non-rebreathing
- Rebreathing
152
What is a non-rebreathing system?
Its where removal of exhaled CO2 depends on an adequate fresh gas flow
153
What are the advantages of a non-rebreathing system?
- The patient inspires fresh gas of a known consumption
- The anaesthetic depth can be chnaged rapidly
154
What are the disadvantages of a non-rebreathing system?
- There is a high fresh gas flow which makes it expensive and increases the potential for enviromental pollution
- The fresh gas is cold and dry so could cause hypothermia and resp dessication
155
Describe how you could calculate FGF using the respiratory minute volume?
* MV = resp rate x tidal volume (10-20 ml/kg)
* FGF = MV x “circuit factor”
156
what is the circuit factor for Lack?
0.8 - 1
157
What is the circuit factor for Ayres T-piece?
2.5 - 3.5
158
What is the circuit factor for a Bain?
1 - 3.5
159
How do you calculate FGF using ml/kg/min in a Lack system?
150-200ml/kg/min
160
How do you calculate FGF using ml/kg/min in a T-piece system?
400-600ml/kg/min
161
How do you calculate FGF using ml/kg/min in a Bain system?
200-600ml/kg/min
162
Why after inhalation, expiration is a expiritory pause crucial?
Fresh gas flushes expired gas out the system in this pause. If the pause is too short there is insufficient time for expired gas to be removed and thats when rebreathing occurs.
163
How do you use nitrous oxide in a non rebreathing system so thta there is still an minumum 30% of O2?
Make sure your allowing 2/3 N2O plus 1/3 O2
164
What patient size can you use a parallel lack on?
10kg and over
165
Is the Parallel lack and minilack sutible for prolonged IPPV
No
166
What size of patient would you use a miniLack on?
10kg or less
167
What is the FGF of a minilack?
200ml/kg/min
168
What is the main difference between the parallel lack and the coaxial lack?
The coaxial lack has its reservoir bag on the inspiritory limb. Its a tube in a tube where as in the parallel lack there the two tubes are seprate.
169
What patients would you use a T-piece in?
Patients up to 10kg
170
T/F the T-piece system is not suitable for IPPV?
False - it is
171
What is the basic T-piece system called?
Mapleson E
172
What are some problems with the Mapleson E?
- There is no reservoir bag so difficult to observe ventilation
- IPPV possible but exposes lungs to a high pressure.
173
What is the name for the modified T-piece system?
Jackson-rees modification
174
Whats different about the Jackson-ree to the Mapleson E
The jackson-ree has an addition of an open-ended bag which allows for observation of respiration and more control during IPPV
175
Describe the mapleson D T-piece
It includes a closed reservoiur bag and APL valve
176
what patients can you use a bain system on?
10Kg and above
177
What is the difference between coaxial bain and lack?
Coaxial Bain is where fresh gas passes up inner tube and expired gas out via outer tube whereas the coaxial lack is where fresh gas passes up outer tube and expired gas out via inner tube.
178
What are advantages of a rebreathing system?
- Lower gas flow used so more economical and enviromental
- gases are warmed and humidified
179
What are the disadvantages of a rebreathing system
- There is a greater resistance to breahing
- It is unsuitable for small patients
- patient inspires a mixture of fresh gas and exhaled gas causing a slower alteration of anaesthetic depth.
180
Describe Soda Limes components
- 80% calcium hydroxide
- 4% sodium hydroxide
- 14-20% added water
- Indicator dye
181
T/F pH of soda lime changes?
Yes which allows use of indicator dye to reveal exhaustion
182
What are the colour changes you would see of soda lime which indicate exhaustion?
Pink to white
OR
White to Purple
183
T/F a high FGF is not needed to expel exhaled CO2 in a rebreathing system?
True meaning a relatively low FGF can be used
184
What are problems that occur during use of a full rebreathing system?
- Flowmeters may be inaccurate
- vaporisers may be inaccurate
- marked dilutional effect
185
When you compare partial to full rebreathing systems what can be said?
- A partial mode should allow flowmeters and vaporisers to be accurate.
- Dilution still occurs but less of it.
186
"Oxygen supplied is just sufficient to meet the patient’s metabolic oxygen requirement" what rebreathing system does this statement match with?
A full rebreathing system
## Footnote
Partial rebreathing - Oxygen supplied is greater than that required for metabolic O2 consumption but less than the minute ventilation.
187
T/F in a partial system there is no gas exiting from the APL valve.
False - This is the case in a full rebreathing system but in a partial all excess gas exits via the APL valve.
188
T/F at the start of anaesthesia using a rebreathing system the patients lungs and breathing system are full of room air?
True
189
What must you do to at the start of ana using a rebreathing system?
Denitrogenate
190
Describe Denitrogenination?
- Use high FGF for the first 10-15 mins of anaesthesia with closed or semi-closed rebreathing system.
- After this lower FGF to allow full/partial rebreathing
191
What are the main concerns when using nitrous oxide in rebreathing systems?
- N2O accumulates reducing O2 concentration (minimum FiO2 0.3)
192
What breathing system would you use for a animal less than 10kg?
T- peice (for IPPV) or minilack
193
For animal 10-15kg what breathing system should you use?
Bain, lack, (circle)
Bain or lack for IPPV
194
For animals greater than 15kg what breathing systems can you use?
- Bain, lack or circle
- Bain or circle for IPPV
195
What does IPPV stand for?
Intermittent Positve pressure ventilation
196
(Prescribing & dispensing: the cascade)
What are problems with unauthorised medicines?
* May not be of consistent quality
* May not be safe and effective
* May pose a risk to consumers
197
What is the cascade?
A mechanism to allow us to prescribe unauthorized medicines to our patients.
198
Is it a legal requirement to seek informed consent?
Nope but recommended by the RCVS
199
Who can prescribe a medcine for an animal using the cascade?
Only a veterinary surgeon
200
T/F a pharmacist can dispense a vetereniary medical product for use under the cascade, human medicines against a prescription from a vet.
true
201
In a prescription for animals intended for the food chain, what must the vet do?
- They must specify withdrawl period
- They must keep additional records
202
203
What is the maximum residue limit?
It is the maximum safe concentration of residue in a food following use of a veterinary product.
204
What is the maximum residue limit measured in?
mg kg-1
205
What is the withdrawl period of a drug?
Period of time, following treatment of an animal with a veterinary medicine, in which the meat, milk, eggs or honey from the treated animal must not enter the food chain due to the possible presence of residues.
206
T/F the responisbility to set an appropriate withdrawl period lies with the vet
True
207
How should you decide on the withdrawl period?
* Check the authorised WP in the SPC
* Was the medicine used in accordance with SPC?
* If not should set at least the “minimum statutory withdrawal period”
* Consider pharmacokinetics
208
what are the minimum statutory withdrawl periods for eggs and milk and different meats?
- eggs and milk = 7days
- poultry and mammal meat = 28 days
- fish meat = 500 degree days
209
what must a vet keep records of when using unautherised medicines in food animals? and how long for?
* Date of examination
* Name and address of owner
* Animal ID and number treated
* Result of clinical assessment
* Trade name of product
* Batch Number
* Name and quantity of active substance
* Dose administered and/or supplied
* Duration of treatment
* Withdrawal Period
210
The cascade has 5 stages, whats stage 1?
A vet medicine authorised in GB or UK wide for use in the indicated species and condition
211
The cascade has 5 stages, whats stage 2?
A vet medicine authorised in NI for indicated species and condition
NB: Special Import Certificate (SIC) from the VMD is required
212
The cascade has 5 stages, what is stage 3?
A vet medicine authorised in GB, NI or UK wide for use in a different species (if a food-producing animal must be another food-producing species)
OR
A product authorised for another condition in the same species
NB: If not authorised in GB or UK a SIC from the VMD is required
213
The cascade has 5 stages, what is stage 4?
A human medicinal product authorised in GB, NI or UK
OR
An authorised vet medicinal product from outside the UK (need SIC)
214
The cascade has 5 stages, what is stage 5?
An extemporaneous preparation prepared by a vet, pharmacist or person holding a Manufacturer’s authorisation in the UK
Exceptional circumstances:
- A human medicinal product imported from outwith the UK (SIC)
215
What is the difference between aloowed and prohibited substances on the MRL register?
- Allowed substances have an MRL that has been established or is being establish or does not need to be established.
- Prohibited substances are where an MRL cannot be established or any residue can be harmful.
216
If it is your first time seeing a horse what should you do before prescribing it anything?
* Check microchip & cross check with passport to make sure the passport relates to the correct horse
* Check Section IX and ask owner to sign horse out of food chain
* Make a note in clinical records (practice database)
217
What if the horse your bout to treat does not have a passport?
* Do not treat the horse if it is not immediately necessary to do so
* Treat the horse as ‘intended for human consumption’ in the first instance
* In an emergency, if health/welfare of horse is at risk treatment with a substance not allowed in food animals is permitted - Need to issue owner with detailed document of medicines administered and instruction to exclude horse from food chain
218
T/F phenylbutazone cannot be used in horses intended for human consumption?
true
219
(Equine field Anaesthetic)
How can you obtain a horses weight?
- Weighing scales
- Measuring band
- Formula
220
Why should you wash out horses mouth berfor anaesthesia?
As you don’t want any food to be aspirated during anaesthetic.
221
When sedating a horse what should you consider?
* Available personnel and their ability to help
* Animal’s temperament
* Type of procedure (length of time, pain level involved)
* Concurrent conditions/illness of the animal
* Behavioural factors
222
In a horse which route is the most reliable for sedation?
- IV - takes 5 mins
223
For a standing sedation what things can you do to make a rapid conversion to GA?
- Have induction drugs at hand and does calculated
- intubation +/- oxygen supplementation ready
224
When using xylazine for a standing sedation in horses what is the bolus rate?
0.4-1mg/kg IV
225
When using xylazine for a standing sedation in horses what is the starting rate for infusion?
0.65mg/kg/hr
226
When using xylazine for a standing sedation in horses what is the commen side effect at high doses and prolonged infusions?
Ataxia
227
When using Romifidine for a standing sedation in horses what is the bolus rate?
0.04-0.1mg/kg IV
228
When using Romifidine for a standing sedation in horses what is the starting rate for infusion?
Starting rate for infusion 0.03 mg/kg/h
229
T/F romifidine is inferior to detomidine when it comes to standing sedation?
True
230
T/F time to maximal sedation and complete recovary is loger with romifidine than other alpha 2 agonists?
true
231
When using Detomidine for a standing sedation in horses what is the bolus rate?
0.01 mg/kg IV
232
When using Detomidine for a standing sedation in horses what is the starting rate for infusion?
Starting rate for infusion: 0.01 - 0.04 mg/kg/h
233
What are other add on opiods for standing setation
* Butorphonal bolus /CRI
* Morphine bolus /CRI
* Buprenorphine bolus for long procedures
* Methadone bolus
234
What drugs might you use for a locoregional anaesthesia?
Lidocaine
Mepivacaine
Bupivacaine
235
What kind of ophthalmic nerve blocks can you do?
Auriculopalpebral nerve block
Frontal nerve block
Zygomatic nerve block
Infratrochlear nerve block
Retrobulbar nerve block
236
What kind of dental nerve blocks can you do?
Maxillary nerve block
Inferior alveolar nerve block
Mental nerve block
Mandibular nerve block
237
What is the 'standard' protocol for most equine anaesthetic inductions
Ketamine/benzodiazepine
238
At what dose should ketamine and benzodiazapine be administered at after sedation?
Ketamine = 2.2mg/kg-1
Diazepam = 50micrograms/kg -1
239
What is the basic formula for a triple drip in horses?
500 ml GGE (Guaiphenesin, guaicol glycerine) + ketamine + α2 agonist
240
What are the advantages of a triple drip?
* Easy
* Cardiovascular function ↑
* Respiratory function ↑ = PaO2↑ & PaCO2 ↓ and Preservation of hypoxic pulmonary vasoconstriction
241
What are the disadvantages of a triple drip?
* Horses appear to be light
* Respiratory pattern changes with TD overdose
* For 90 minutes MAX!!!
* Drug accumulation: poor recoveries possible
242
What are signs that an equine anaesthesia is too light?
- swallowing
- blinking
- twitching
243
1. Midazolam substituted for GGE in Triple Drip recipes with ketamine and xylazine
* 1 L NaCl 0.9%
* + Midazolam (50 mg)
* + ketamine (1000 mg)
* + xylazine (500 mg)
o Starting rate 2.2 mL/kg/h
o Anecdotally reported as similarly effective
2. Midazolam substituted for GGE in Triple Drip recipes with ketamine and xylazine
* 1 L NaCl 0.9%
* + Midazolam (50 mg)
* + ketamine (1000 mg)
* + xylazine (500 mg)
o Starting rate 2.2 mL/kg/h
o Anecdotally reported as similarly effective
BREAK THIS DOWN
244
What should you do for procedures lasting less than 20mins?
* Standard premedication
* Induction with ketamine (± diazepam)
245
What should you do for intermediate procedure lasting between 20 and 40mins?
* Standard premedication - With longer acting α2 agonists and with xylazine (xylazine top-upped together with ketamine)
* Standard induction = (7–)10 min: 1/3 – 1/2 of ketamine dose (Maximum of 3 top-ups)
* OR Triple drip (especially when expected to take > 30 min)
246
what should you do in longer procedure 30-90min?
* ‘Triple Drip’ technique
* Standard sedation and induction
* use same α2 agonist for premedication and triple drip
* Infusion rate initially at set rate and then adjusted ‘to effect
* GAs > 60 min - Ideally ability to ventilate should be present
247
What are the advantages of intubating horse?
* Airway maintenance and protection
* IPPV possible if large animal ventilator available
* Easy to perform
248
What are the disadvantages of intubating horses?
* Not without risks
* Large animal ETTs expensive
* IPPV not an option without large animal ventilator
249
(How to provide adequate analgesia)
Describe the general pathophysiology of pain
- Stimulus is picked up by the nociceptors
- This is transferred through the peripheral nervous system
- It is taken to the dorsal horn of the spinal cord
- Then fibres transmit the signal up to the brain for processing
- Then that pain is sensed
250
What do both products of damaged cells and inflammatory mediators cause to the firing rate?
They cause an increase in firing rate = nerves firing more frequently
251
What do both products of damaged cells and inflammatory mediators cause to the firing threshold?
They cause a decrease in firing threshold = less time to send signal of pain from stimulus to spinal cord
252
T/F products of damaged cells and inflammatory mediators cause normally silent nocioceptors to be activated?
True = more input to spinal cord.
253
What is central sensitisation?
Response to persistent or repaeated barrages of nocioceptive input.
254
What is the response central sensitisation presents?
- Increase in firing rate in spinal cord neurones
- increase in receptive area
- Non-painful stimuli becomes painful (allodynia)
255
What is pre-emptive analgesia?
The administration of analgesic agents before the onset of nociceptive stimulation.
256
What is multimodal analgesia?
The use of more than one analgesic agent to provide analgesia
257
How does analgesics effect transduction, transmission, modulation and perception?
- Effects transduction by affecting the firing of nociceptors
- Effects transmission by affecting impulses to spinal cord
- Modulation - ?
- Effcets perception by blocking it but not the impact of nocioceptors.
258
What are the differecent types of analgesic drugs?
- opiods
- NSAIDS
- local ana
- Alpha -2- agonists
- ketamine
259
What si the clinical use of opiods?
- pre-med
- Intermittent bolus - IV/IM/transmucosal
- Infusion
- In epidural
260
What is the infusion rate for morphine in dogs? and does it change for cats?
0.1-0.2mg/kg/hr and lower in cats
261
What is the infusion rate for methadone?
0.08-0.16mg/kg/hr
262
What is the infusion rate of fentanyl?
2-10mg/kg/hr
263
Who is a fentanyl infusion most effective with?
small dogs and cats
264
Where can local ana be used for perineural blocks?
limb
- brachail plexus
- RUMM block
- Femoral and sciatic
- Digital
Dental
- Maxillary
- Mental
- Imfraorbital
- mandibular
265
What will a lumbosacral epidural desensitise?
Perineum, Hindlimbs and (abdomen)
266
What would you use lidocaine infusion for?
Visceral pain
267
What animals must you not use a lidocaine infusion in?
Cats
268
T/F you can have a combined infusion or morphine, lidocaine and ketamine?
True
269
How might you clinically use alpha-2 agonists for analgesia?
- infusion
- adjunct to local ana in perineural block
- epidural
270
Why would you use an Alpha-2 in conjusction with a local ana in a perineural block?
It prolongs the effect.
271
What are the clinical uses of ketamine for analgesia purposes?
- Pre-existing pain
- Predisposed to developing 'chronic pain' ie amputation
- Adjunctive analgesia with difficult to manage pain
272
With difficult to manage pain, what infucion and bolus rate would you set ketamine at?
Infusion = 0.3-0.6 mg/kg/hr
Bolus = 0.25.0.5 mg/kg
273
what analgesia - methadone or fentanyl - would you use for an OVH when dogs been premeded with pethidine/meloxicam and has recovered in alot of pain.
Methadone would be good here IV as it has a reasonably good onset of action and will give a longer duration than Fentanyl. Fentanyl is good as shed in alot of pain but it only last 20mins so will have to top up.
274
What analgesia would you use - Fentanyl or methadone - during ana of a removal of a mass in shoulder region of a dog with a bad ana.
Fentanyl is good here as it has a rapid onset Iv and control situation. can give bolus but can also give an infusion to maintain pain relief. Methadone isnt as flexabile as fentanyl.
275
Should you use NSAIDs in a cat presented following RTA with a pelvic injury. Cat has HR of 280/min and a weak femoral pulse?
Sounds hypervolemic and some degree of shock so no NSAIDs until these factors are managed as could cause liver/kidney issues.
276
Should you use NSAIDs in a doberman with Von Willebrand disease presented for routine castration?
NO as they can effect clotting so dont want to make it worse.
277
Should you use NSAIDs in an atopic dog on alternative day predinsalone who is presenting for multiple skin biopsies?
NO becuase of the prednisalone as we dont want to use steroif and NSAIDs together.
278
Should you use NSAIDs with an asthmatic cat under going amputation of the distal tail?
NO as they can effect the resp system. Use with caution.
