Study Questions 1.9 Complications

Front 1

Sudden waking. When does it happen and how do you manage it?

Back 1

Occurrence
1. Transition from induction to maintenance phase
2. During maintenance of anaesthesia


Management:
careful administration of IV anaesthetic until movement controlled and then correct cause

Front 2

Sudden waking: Induction maintenance , what are the 3 reasons for poor gas delivery during transition?

Back 2

Alveolar ventilation
Oesophageal intubation
Equipment factors

Front 3

What are the causes of inadequate ventilation? 4
How do we fix it?

Back 3

Breath-holding (too light)
Apnoea (too much too quickly)
Obesity
Gastric distension

Increase tidal volume

Front 4

How do we Poor gas delivery: ii) Oesophageal intubation ? How do we manage it?

Back 4

Detection:
Direct visualisation
Palpation of ETT in oesophagous
Capnography

Management: re-intubate

Front 5

What happens during maintenance phase leading to sudden waking?

Back 5

Maintenance phase
Sudden increase in stimulation
Interruption to gas delivery to circuit
Inadequate gas delivery to lungs

Front 6

How do we manage sudden waking in maintenance phase?

Back 6

Due to marked increase in stimulation.

Monitor, provide appropriate analgesia.

Front 7

Interruption of gas delivery to patient leading to sudden waking is due to ?

Back 7

1. Cuff deflates leads to dilution og gases
2. Vaporiser empty
3. Oxygen empty
4. DIsconnection of patient from circuit.

Front 8

What 3 factors lead to Inadequate delivery to lungs ?

Back 8

Inadequate delivery to lungs
i) Leak around ETT
ii) Poor ventilation
iii) Bronchial intubation

Front 9

What are the signs of inadequate ventilation and how do we detect it?

Back 9

Inadequate ventilation
Tachypnoea/panting → marked reduction in TV → ventilation of airways
Detection:
respiratory pattern
Capnograph

Front 10

What causes inadequate delivery to lungs? How do you detect it?

Back 10

iii) endobronchial intubation

Detection
Change in breathing pattern
Decreased oxygen saturation (shunt)
Auscultation of chest

Front 11

What are the 3 things that indicate Inadequate gas delivery ?

Back 11

Inadequate gas delivery:
i) Leak
smell of gas;
Audible noise at patient mouth,
loss of plateau on capnograph

Front 12

What clinicals signs would indicate inadequate ventilation? How would you detect it?

Back 12

Tachypnoea/panting → marked reduction in TV → ventilation of airways
Detection:
respiratory pattern
Capnograph

Front 13

Endobronchial intubation would cause Inadequate delivery to lungs. How would you detect this? Prevent it and measure it?

Back 13

Change in breathing pattern
Decreased oxygen saturation (shunt)
Auscultation of chest.
Prevent
Pre-measure ETT and cut to correct length

Management
Move ETT into trachea
Replace with shorter tube

Front 14

What are the causes of Tachypnoea? 3

Back 14

1. pain
2. Some opioids
e.g. Methadone, fentanyl
3.Response to change in O2 or CO2
(suppressed by anaesthesia)

Front 15

What are the consequences of Tachypnoea? 3

Back 15

Consequence
Reduced uptake of anaesthetic gas: waking

Reduced CO2 removal

+/- Reduced oxygen delivery (uncommon on 100% oxygen)

Front 16

what cells are active in the production of INF-gamma? (3)

Back 16

1. TH1
2. CD8
3. NK cells

Front 17

What are the 4 causes of apnoea

Back 17

Too light: breath-holding at induction

Too much induction agent too quickly

Excessive anaesthetic

High dose opioid administration

Front 18

What are the consequences of breath holding and excess opiod administration ?

Back 18

Breath-holding =
Animal may wake up (breath-holding)

Excess anaesthetic/opioid administration =
Hypercapnia
Hypoxaemia
Progress to cardiac arrest

Front 19

What are the management of apnoea?

Back 19

1. Assist ventilation
until cause corrected.

2.Reduce anaesthetic
depth if appropriate

Front 20

What is the definition of hypoxaemia?

Back 20

Definition: FI02 21 % (room air)
Below normal: PaO2 <80 mmHg; SPO2 < 95 %
Marked hypoxaemia: PaO2 < 60 mmHg; SpO2 < 90 %

Front 21

What is the consequences of hypoxaemia?

Back 21

Reduced tissue oxygenation
>Organ damage: kidney, brain, heart, GIT, skeletal muscle >Respiratory and eventual cardiac arrest

Front 22

What are the 2 causes of hypoxaemia?

Back 22

Decreased oxygen delivery to circuit
[See above: causes of decreased gas delivery]


Decreased oxygen delivery to patient
Use of N2O
Atelectasis
Pulmonary disease

Front 23

What is the effect of reduced oxygen due to increased N2O? 2

Back 23

High inspired concentration of N2O decreases inspired oxygen


Diffusion hypoxia

Front 24

What are the causes of atelectasis? 3
How would you manage this?

Back 24

Cause
1. reduced lung volume: obesity, git distension
2. 100% oxygen
3. Nitrous oxide

>>Management of atelectasis
IPPV +/- PEEP (see supportive care)

Front 25

Give examples of pulmonary pleural diseases.

Back 25

1. Pneumothorax
overzealous ventilation
Traumatic intubation
2. Oedema

Front 26

What is the definition of hypercapnea? What are the clinical signs?

Back 26

PaCO2 > 65
ET CO2 > 60

Dark pink/red mm
Decreased CV
function
Unexplained arrhythmias

Front 27

What are the consequences of hypercapnia

Back 27

Sympathetic stimulation: increased HR, VC
>
Direct CV depression: decreased contractility, VD
>CNS depression narcosis >Cardiopulmonary arrest

Front 28

What are the common causes of hypercapnia and 2 less common ones?

Back 28

Common causes
Reduced ventilation
Rebreathing


Less common causes
Hyperthermia e.g pigs
Laproscopy

Front 29

What are the 3 causes of reduced alveolar ventilation that leads to hypercapnia?

What are the 2 ways to manage it?

Back 29

1. Opiods
2. Isofluranes
3. Obesity

Management:
Asssisted/mechanical ventilation
Reduce drug administration if possible

Front 30

What are the 3 causes of rebreathing tha leads to hypercapnia?

Back 30

1.Exhausted sodalime (rebreathing system)
2.Inadequate oxygen flow (non-rebreathing system)
3.Dead space large

Front 31

How would you confirm rebreathing?

Back 31

Confirmation requires capnography → elevated baseline

Front 32

What are the consequences of tachycardia?

Back 32

1.Increased heart rate >
2.Decreased time for filling during diastole >
3.Decreased stroke volume and cardiac output >
4. Decreased BP

Front 33

What are the 4 causes of tachycardia that accompanies increased BP ?

Back 33

i) Response to stimuli/pain
ii). Drugs: ketamine, atropine
iii) Hypoxaemia (mild)
iv). Hypercapnia (mild-moderate)

Front 34

What are the 4 causes of tachycardia that accompanies normal or decresed BP ?

Back 34

i)Hypovolaemia: volume loss
ii)Xs prolonged VD
iii) ↓ cardiac contractility
iv) Obstruction to venous return

Front 35

How do you manage Tachycardia associated with increased BP ?

Back 35

1. Ensure adequate analgesia
and anaesthesia:
2.Ensure adequate
O2 delivery and ventilation
3. Secondary to Drugs:
Wait for effect to wear off
beta blocker

Front 36

How do you manage Tachycardia associated with normal or decreased BP? 4

Back 36

1. Decrease volatile agents
2.Ensure normal blood volume
3.Pharmacological
support
4. Remove
obstruction to flow

Front 37

What are the consequences of tachycardia?

Back 37

1.Increased heart rate >
2.Decreased time for filling during diastole >
3.Decreased stroke volume and cardiac output >
4. Decreased BP

Front 38

What are the 4 causes of tachycardia that accompanies increased BP ?

Back 38

i) Response to stimuli/pain
ii). Drugs: ketamine, atropine
iii) Hypoxaemia (mild)
iv). Hypercapnia (mild-moderate)

Front 39

What are the 4 causes of tachycardia that accompanies normal or decresed BP ?

Back 39

i)Hypovolaemia: volume loss
ii)Xs prolonged VD
iii) ↓ cardiac contractility
iv) Obstruction to venous return

Front 40

How do you manage Tachycardia associated with increased BP ?

Back 40

1. Ensure adequate analgesia
and anaesthesia:
2.Ensure adequate
O2 delivery and ventilation
3. Secondary to Drugs:
Wait for effect to wear off
beta blocker

Front 41

How do you manage Tachycardia associated with normal or decreased BP? 4

Back 41

1. Decrease volatile agents
2.Ensure normal blood volume
3.Pharmacological
support
4. Remove
obstruction to flow

Front 42

What are the consequences of tachycardia?

Back 42

1.Increased heart rate >
2.Decreased time for filling during diastole >
3.Decreased stroke volume and cardiac output >
4. Decreased BP

Front 43

What are the 4 causes of tachycardia that accompanies increased BP ?

Back 43

i) Response to stimuli/pain
ii). Drugs: ketamine, atropine
iii) Hypoxaemia (mild)
iv). Hypercapnia (mild-moderate)

Front 44

What are the 4 causes of tachycardia that accompanies normal or decresed BP ?

Back 44

i)Hypovolaemia: volume loss
ii)Xs prolonged VD
iii) ↓ cardiac contractility
iv) Obstruction to venous return

Front 45

How do you manage Tachycardia associated with increased BP ?

Back 45

1. Ensure adequate analgesia
and anaesthesia:
2.Ensure adequate
O2 delivery and ventilation
3. Secondary to Drugs:
Wait for effect to wear off
beta blocker

Front 46

How do you manage Tachycardia associated with normal or decreased BP? 4

Back 46

1. Decrease volatile agents
2.Ensure normal blood volume
3.Pharmacological
support
4. Remove
obstruction to flow

Front 47

Tachyarrhythmia:What are the 2 Causes? Give examples in each

Back 47

1. Interference with myocardial oxygen delivery
>Prolonged increase HR
>Anaemia
>Hypovolaemia
>Hypoxaemia

2. Myocardial irritants
>Acidosis: respiratory or metabolic
>thiopentone,ketamine, atropine, halothane
>Electrolyte abnormalities

Front 48

How would you manage Tachyarrhythmia?
When are anti arrythmias indicated?

Back 48

1. Correct underlying cause
2. Reduce sympathetic stimulation:
Anti-arrhythmics are indicated if:-
Abnormal perfusion
Rate > 180
multifocal

Front 49

Bradycardia: definition

Back 49

Clinically significant bradycardia
↓ BP and tissue perfusion
Abnormal rhythm (except sinus arrhythmia)

Front 50

Bradycardia/bradyarrhythmias: consequence?

Back 50

Decreased heart rate >
Decreased CO
(CO = HR x SV) >Decreased
BP

Front 51

Bradycardia/bradyarrhythmias: cause 5 ?

Back 51

1. XS anaesthesia
2. Electrolytes: K, calcium
3. Severe hypoxaemia
4. Marked hypothermia (< 33 C)

Front 52

Bradycardia/bradyarrhythmias: management

Back 52

Correct cause where possible
Reduce /reverse drug administration
Correct oxygenation
warm

Increase HR pharmacologically
Anticholinergics

Front 53

What is the definition and cause of hypertension?

Back 53

Definition
Mean BP > 100 mmHg
Systolic BP > 140 dogs; > 160 cats


Cause
Sympathetic nervous system activation

Front 54

What are the 3 common sources of hypertension?

Back 54

Mild-moderate
Hypoxaemia/hypercapnia
due to pain and ketamine = increased HR

Associated with ↓ HR >> drugs

Front 55

Hypertension: Cause: Less common (2)

Back 55

Increased ICP (cushing reflex): initial increase then decrease HR

Endocrine disease: HR may be increased or decreased

Front 56

Hypertension: consequence of prolonged VC (2)

Back 56

1.Decreased perfusion
of tissues
2. Increased work
of the heart

Front 57

Hypertension: management 2

Back 57

Reduce sympathetic stimulation
adequate analgesia
reduce/reverse drugs if possible
pharmacologically


Increased ICP: mannitol +/- frusemide

Front 58

Hypotension , define

Back 58

Definition
Mean arterial BP < 60 mmHg
Systolic arterial BP < 80 mmHg

Front 59

Hypotension: consequence

Back 59

low BP leads to decreased tissue perfusion > tissue death

Front 60

What are the 4 causes of hypotension. Give examples.

Back 60

Cause: 1. Peripheral VD >> ace, propofol, alfaxolone, Marked hypercapnia or hypoxaemia
2. hypovolaemia >> haemorrhage
Cause 3. cardiac >> Bradycardia, tachycardia, decreased contractility
4. obstruction to venous return, GDV

Front 61

How would you manage hypotension?

Back 61

1. Correct cause if possible


2. Symptomatic
Fluids
Reduce anaesthetic depth and
dopamine

Front 62

What are the causes of regurgitation?

Back 62

1. Inadequate fasting
2. Reduced lower
oesophageal sphincter tone

Front 63

What are the consequences of regurgitation?

Back 63

Consequences
Aspiration
Induction/recovery
Deflation of cuff
Oesophagitis → oesophageal stricture

Front 64

How do you prevent regurgitation? 3

Back 64

Induction:
sternal head/elevated
Cricoid pressure until intubation
Suction stomach (if full)

Recovery
Suction stomach prior recovery
Maintain ETT as long as possible

Prevent oesophagitis: Administer H2 blockers

Front 65

How do yo manage regurgitaion during induction, maintenance and recovery of anaesthesia?

Back 65

Induction:
Place head over edge of table
Suction/swab pharynx prior intubation

Maintenance
Ensure cuff inflated

Recovery:
Suction/swab pharynx prior extubation
Suction and lavage oesophagous
Maintain ETT with cuff inflated as long as possible

Front 66

Gastric distension: Cause/Predisposing factor 3

Back 66

1. Ingestion of air
due to excitement on induction
Sudden waking after induction/during maintenance
2. Oesophageal intubation
3. Ventilation by mask

Front 67

Gastric distension: list 3 consequences.

Back 67

Predispose to torsion in susceptible breeds

Impedes movement of diaphragm

Interferes with venous return

Front 68

Gastric distension: management 2.

Back 68

Decompress stomach
Pass stomach tube

Trocharisation

Front 69

Pre-renal/Renal failure >> 2 causes.

Back 69

Cause
Prolonged untreated hypotension/hypoxaemia

Nephrotoxic agents
NSAID ( in presence of hypotension)
Contrast ( CT, myelograms)

Front 70

Gastric distension: list 3 consequences.

Back 70

Predispose to torsion in susceptible breeds

Impedes movement of diaphragm

Interferes with venous return

Front 71

Pre-renal/renal failure: prevention >> 2 ways

Back 71

1. Administer fluids
2. Monitor BP

Front 72

Gastric distension: management 2.

Back 72

Decompress stomach
Pass stomach tube

Trocharisation

Front 73

Gastric distension: list 3 consequences.

Back 73

Predispose to torsion in susceptible breeds

Impedes movement of diaphragm

Interferes with venous return

Front 74

Pre-renal/Renal failure >> 2 causes.

Back 74

Cause
Prolonged untreated hypotension/hypoxaemia

Nephrotoxic agents
NSAID ( in presence of hypotension)
Contrast ( CT, myelograms)

Front 75

Pre-renal/renal failure: prevention >> 5

Back 75

Do not administer NSAID/corticosteroids to at risk animals
Older animals
Pre-existing renal disease
Possible blood loss
Pre-existing CV disease

Correct hypoxaemia/hypovolaemia ASAP

Front 76

Gastric distension: management 2.

Back 76

Decompress stomach
Pass stomach tube

Trocharisation

Front 77

Pre-renal/Renal failure >> 2 causes.

Back 77

Cause
Prolonged untreated hypotension/hypoxaemia

Nephrotoxic agents
NSAID ( in presence of hypotension)
Contrast ( CT, myelograms)

Front 78

Pre-renal/renal failure: prevention >> 2 ways

Back 78

1. Administer fluids
2. Monitor BP

Front 79

Pre-renal/renal failure: prevention >> 5

Back 79

Do not administer NSAID/corticosteroids to at risk animals
Older animals
Pre-existing renal disease
Possible blood loss
Pre-existing CV disease

Correct hypoxaemia/hypovolaemia ASAP
Monitor urine production post-operatively
Take your dog for a walk
Check litter tray in cats cage

Place urine catheter in at risk animals

Front 80

Pre-renal/renal failure: prevention >> 2 ways

Back 80

1. Administer fluids
2. Monitor BP

Front 81

Pre-renal/renal failure: prevention >> 5

Back 81

Do not administer NSAID/corticosteroids to at risk animals
Older animals
Pre-existing renal disease
Possible blood loss
Pre-existing CV disease

Correct hypoxaemia/hypovolaemia ASAP
Monitor urine production post-operatively
Take your dog for a walk
Check litter tray in cats cage

Place urine catheter in at risk animals

Front 82

What are the 7 consequences of hypothermia?

Back 82

↓ anaesthetic requirement → predispose to OD
CV depression : hypotension (< 33 C)
Prolonged recovery
Increased risk of infection
Decreased wound healing
Poor clotting
Shivering on recovery → increased O2 demand

Front 83

Hypothermia:cause/predisposing factors >> 4

Back 83

1. Large body surface area: neonates; small animals
2. Vasodilation: drugs
3. open body cavity
4. Cold environment: tables, air

Front 84

Hypothermia: prevention/management>> 2

Back 84

Provide warmth > air, water, heat packs
Careful use of (long acting) vasodilating drugs in at risk animals

Front 85

What are the 3 causes of CPA?

Back 85

Anaesthetic overdose

Any CV or pulmonary complication if severe or prolonged

Severe electrolyte/acid base disturbance

Front 86

CPA management

Back 86

Cardio pulmonary cerebral resuscitation
Covered in detail in ECC lectures
Principles: ABC DEF

Basic CPR = ABC = most important
Advanced CPR = DE = support ABC

Front 87

Basic CPCR.
5

Back 87

1.Turn off anaesthetic gases/drug infusions
2.A: airway
Check ETT patent , connected to circuit

3.Replace tube if obstructed

4. B = breathing
start IPPV
C5 . Before proceeding: Assess efficacy of compressions
Pulse (equivocol)
Retinal blood flow (Doppler)
Capnography

Front 88

Advanced CPCR. What are the 3 main drugs. How would you use an ECG?

Back 88

D = drugs

Drugs support circulation.
Adrenalin
Atropine
Reverse sedative/anaesthetic drugs
E = ECG
Guides drug administration/treatment

Determines return of spontaneous electrical activity

Front 89

What is the follow up of CPCR?

Back 89

F = follow-up (if CPCR successful)

Support pulmonary and CV function
IPPV until adequate spontaneous breathing
Oxygen supplementation
Fluids +/- inotropes

Monitor organ function closely