Anaesthetics

Question 1

3 A’s of anaesthesia

Answer 1

Amnesia
Analgesia
Akinesia

Question 2

Induction agent you CANNOT use in porphyria

Answer 2

Thiopentone

Question 3

Induction agent used for RSI

Answer 3

Thiopentone

Question 4

Induction agent you CAN’T use in sepsis

Answer 4

Etomidate

Question 5

How long do induction agents last

Answer 5

4-10 minutes

Question 6

MAC of sevoflourane

Answer 6

2%

Question 7

MAC of isoflourane

Answer 7

1.15%

Question 8

Indication of isoflourane

Answer 8

Organ donation - doesn’t affect blood flow to organs

Question 9

Indication for desflourane as maintenance

Answer 9

Long operation (doesn’t accumulate in fat)

Question 10

Anti-emetics given DURING surgery

Answer 10

Dexamethasone

Ondansetron

Question 11

Post-op anti-emetic

Answer 11

Cyclizine

Question 12

Define amnesia in terms of anaesthetics

Answer 12

Lack of response and recall to noxious stimuli (e.g. unconscious)

Question 13

What are the biggest cannulas?

Answer 13

Orange
Grey
White
Green
pink
blue
yellow
violet

Question 14

Effect of propofol on HR and BP

Answer 14

Reduces both HR and BP

Question 15

Effect of thiopentone on HR and BP

Answer 15

Drops BP

Increases HR

Question 16

Which anaesthetic tends to be used in neurosurgery and why?

Answer 16

Thiopentone –> antiepileptic properties and neuroprotective

Question 17

When would etomidate be used for induction?

Answer 17

Haemodynamic instability e.g. heart failure

Question 18

Which induction agent has the highest incidence of PONV

Answer 18

Etomidate

Question 19

Why cannot etomidate be used in septic shock?

Answer 19

Causes adreno-cortical suppression

Question 20

What maintenance agent would you use for organ donation and why?

Answer 20

Isoflourane because it has the least effect on blood flow

Question 21

What maintenance agent is commonly used in children?

Answer 21

Sevoflourane

Question 22

What maintenance agent is commonly used in long procedures and why?

Answer 22

Desflurane - less accumulates in fat so more rapid onset and offset

Question 23

What is the mac of sevoflourane?

Answer 23

2%

Question 24

MAC of desflourane

Answer 24

6%

Question 25

MAC of isoflurane

Answer 25

1.15%

Question 26

Which short acting opioids are most commonly used and fastest acting?

Answer 26

Most common = fentanyl | Fastest acting = remifentanyl (IV infusion)

Question 27

Side effects of NSAIDS as pain relief

Answer 27

Gastric and renal SEs Interfere with clotting (CI in asthma)

Question 28

What does activating alpha receptors in vascular smooth muscle cause and which commonly used drugs do this?

Answer 28

Induces smooth muscle contraction (vasoconstriction). Works through second messenger (cAMP) model. Happens in both arteries and veins but more pronounced affect in arteries. Vasopressors (systemic vasoconstrictors) --> metaraminol, phenylephrine, ephedrine.

Question 29

What does activating beta receptors in vascular smooth muscle cause and which commonly used drugs do this?

Answer 29

Beta receptors are mainly in cardiac smooth muscle. Activating them causes cardiac stimulation (increased HR, contractility, cardiac output) and increased vasodilation systemically. Ionotropes = adrenaline, ephedrine, dobuatmine

Question 30

What does hypertension during anaesthesia indicate?

Answer 30

Inadequate anaesthesia - give more + analgesics

Question 31

Difference between crystalloid and colloid fluids

Answer 31

Crystalloid = crystalline solids dissolved in water e.g. NaCl. Either hypotonic or isotonic. Colloid = high molecular weight particles e.g. albumin. Expand intravascular volume. Risk of anaphylaxis.

Question 32

What is Hartmann's V 0.9% saline

Answer 32

Both isotonic crystallines. Hartmann's contains sodium, chloride, potassium, lactate

Question 33

At what % of blood volume loss would you consider blood replacements and activating MHP

Answer 33

30% volume loss = blood replacement MHP = >70ml/kg blood loss

Question 34

What is the MHP

Answer 34

RBCs, FFP, platelets in 1:1:1

Question 35

Ondansentron MOA

Answer 35

Serotonin blocker

Question 36

Dexamethasone MOA

Answer 36

Steroid

Question 37

Cyclizine MOA

Answer 37

Anti-histamine

Question 38

Prochlorperazine MOA

Answer 38

Phenothiazine

Question 39

Pre-op assessment

Answer 39

PMHx - AIRWAY - teeth, dentures, neck pain BREATHING/RESP - asthma, cough, trouble breathing, smoker CIRCULATION - CV problems, lying flat, orthopnoea, exercise tolerance GI - GORD, last meal OTHER - diabetes, epilepsy, CKD, thyroid, stroke MEDS - anticoagulation/antiplatelets, insulin, analgesia ANA Hx - problems (MH, ICU, pain, PONV, airway), FHx, Pain relief EXAMINATION - mallampatti (class 1-4), neck and jaw movements, pregnancy, BMI ASA GRADE and PRE-OP IX

Question 40

ASA Grades

Answer 40

* Grade I: healthy, no systemic disease * Grade 2: mild systemic disease, no functional limitations * Grade 3: severe systemic disease, substantive functional limitations * Grade 4: severe systemic disease which is a constant threat to life * Grade 5: at point of death, not expected to survive with or without operation * Grade 6: brain-stem dead, organs being donated

Question 41

Investigations indicated in everyone above >80

Answer 41

FBC U&E ECG (if ASA 3/4: clotting, lung function/ ABG)

Question 42

When would CXR be indicated as pre-op investigation?

Answer 42

If ICU admission or respiratory disease in ASA 3 or 4

Question 43

``` Fasting time for: Solid food Clear fluids Alcohol Breast feeding Children water ```

Answer 43

``` Solid food - 6 hours Clear fluids - 2 hours Alcohol - 24 hours Breast feeding - 4 hours Children water - 30ml max one hour before ```

Question 44

Lignocaine dose

Answer 44

3mg/kg (7mg/kg w adrenaline)

Question 45

Bupivicaine dose

Answer 45

2mg/kg (2mg/kg)

Question 46

Prilocaine dose

Answer 46

6mg/kg (9mg/kg)

Question 47

Anti-emetic generally used in surgery

Answer 47

Dexamethasone

Question 48

Anti-emetic generally used post-surgery

Answer 48

Ondansentron

Question 49

Give an example of colloid fluids

Answer 49

Gelofusine Isoplex Gelaspan

Question 50

Give an example of colloid fluids

Answer 50

Gelofusine Isoplex Gelaspan

Question 51

Adult requirements for fluid and electrolytes for maintenance?

Answer 51

25-30ml/kg water 1mmol / kg potassium, sodium, chloride 50-100g/day glucose