gas notes 1

Question 1

dantrolene

Answer 1

the only drug that treats malignant hyperthermia

Question 2

mallampati score

Answer 2

Question 3

ASA classification for patient fitness for surgery

Answer 3

six classes:

Question 4

What does the American Society of Anesthesiologists Classification (ASA) describe?

Answer 4

A patient’s fitness for surgery

The ASA classification helps in assessing surgical risk.

Question 5

What is the definition of ASA Class I?

Answer 5

A normal healthy patient

Healthy, non-smoking, fit patient.

Question 6

What characterizes ASA Class II?

Answer 6

A patient with mild systemic disease

BMI 30-40, smoking, perhaps a well-controlled ‘lifestyle’ disease with no functional impact.

Question 7

What defines ASA Class III?

Answer 7

A patient with severe systemic disease

BMI > 40, severe functional limitation from poorly-controlled disease.

Question 8

What is the definition of ASA Class IV?

Answer 8

A patient with severe disease that is a constant threat to life

Currently failing organs (heart, lungs, kidneys) but doesn’t need this surgery to survive.

Question 9

What does ASA Class V refer to?

Answer 9

A moribund patient who would not survive without surgery

This class indicates critical condition requiring immediate intervention.

Question 10

What is the definition of ASA Class VI?

Answer 10

A brain-dead patient who is an organ donor

This classification is used for patients who have lost all brain function.

Question 11

Fill in the blank: ASA Class I is for a _______.

Answer 11

normal healthy patient

This class represents the lowest surgical risk.

Question 12

True or False: ASA Class IV patients require surgery to survive.

Answer 12

False

ASA Class IV patients do not need the surgery to survive.

Question 13

common risks of anaesthesia

Answer 13

sore throat
drowsiness
headache
nausea and vomiting

Question 14

rare risks of anaesthesia

Answer 14

dental injury
emergence delirium
aspiration pneumonia
awareness

Question 15

life threatening risks of anaesthesia

Answer 15

anaphylaxis
death

Question 16

how long do patients have to fast

Answer 16

eight hours for solids and two hours for clear fluids

Question 17

triad of anaesthesia

Answer 17

amnesia, analgesia and muscle relaxation

Question 18

pre oxygenation

Answer 18

After induction, patients will have a period of apnoea. To extend the safe apnoeic time, we pre-oxygenate patients with 100% O2 to replace the nitrogen-rich air in their lungs.

Once apnoeic, that extra oxygen continues to diffuse across the alveolar membrane and maintains oxygenation for about four times longer than normal air.

Question 19

A patient is sufficiently pre-oxygenated when

Answer 19

the expired concentration of oxygen is greater than 80% (i.e. FetO2 ≥ 0.8).

Question 20

What is the purpose of paralysis in intubation?

Answer 20

To facilitate intubation and to avoid awareness during surgery

Awareness refers to the experience of being awake but unable to move or breathe.

Question 21

When should paralysis occur in relation to anesthesia?

Answer 21

After patients have fallen asleep

This timing is crucial to prevent awareness.

Question 22

What is the onset time for Rocuronium?

Answer 22

90 s

Question 23

What is the duration of action for Vecuronium?

Answer 23

30 min

Question 24

What is the onset time for Suxamethonium?

Answer 24

30 s

Question 25

What is the duration of action for Cisatracurium?

Answer 25

40 min

Question 26

True or False: Vecuronium has a longer onset time than Rocuronium.

Answer 26

True

Question 27

What is the onset time for Vecuronium?

Answer 27

3 min

Question 28

List the four muscle relaxants routinely used in Australia.

Answer 28

* Suxamethonium * Rocuronium * Vecuronium * Cisatracurium

Question 29

How is bronchospasm managed during anaesthesia?

Answer 29

Inhaled bronchodilators ## Footnote Inhaled bronchodilators are used similarly to how they are used in awake patients.

Question 30

Name three inhaled bronchodilators used to manage bronchospasm.

Answer 30

* Salbutamol * Terbutaline * Ipratropium ## Footnote These medications help to relax and open the airways.

Question 31

What should be done if inhaled therapy for bronchospasm is not effective?

Answer 31

Switch to IV therapy ## Footnote IV therapy is indicated when inhaled medications do not relieve bronchospasm.

Question 32

Name two intravenous therapies that can be used for bronchospasm management.

Answer 32

* Aminophylline * MgSO4 * Ketamine ## Footnote These medications can be administered intravenously if inhaled therapies fail.

Question 33

True or False: Wheeze should be treated without considering its trigger.

Answer 33

False ## Footnote It is important to identify the trigger of wheeze before treatment.

Question 34

What are common triggers of bronchospasm during anaesthesia?

Answer 34

* Volatile agents * Anaphylaxis * Asthma * Respiratory infections ## Footnote These factors can provoke bronchospasm, especially in sensitive individuals.

Question 35

Fill in the blank: Kids with _______ infections are known to bronchospasm with minimal provocation.

Answer 35

respiratory ## Footnote This highlights the sensitivity of children to bronchospasm when they have respiratory infections.

Question 36

what causes hypotension and bradycardia?

Answer 36

Hypotension with bradycardia is usually related to an oversized discharge of acetylcholine from the parasympathetic nervous system.

Question 37

Which types of surgery are especially likely to trigger acetylcholine discharge?

Answer 37

Surgery of the abdomen and cervix are especially likely to trigger such a discharge.

Question 38

What is the solution for hypotension with bradycardia?

Answer 38

The solution is to give atropine or glycopyrrolate.

Question 39

What do atropine and glycopyrrolate do?

Answer 39

They antagonise the muscarinic acetylcholine receptor.

Question 40

Fill in the blank: Hypotension with bradycardia is usually related to an oversized discharge of _______ from the parasympathetic nervous system.

Answer 40

acetylcholine

Question 41

True or False: Surgery of the abdomen and cervix can trigger bradycardia.

Answer 41

True

Question 42

name three volatile agents

Answer 42

sevoflurane desflurane nitrous oxide

Question 43

What does MAC stand for?

Answer 43

Minimum alveolar concentration ## Footnote MAC is pronounced “mack” and refers to the concentration of anaesthetic agent needed to produce immobility in 50% of subjects.

Question 44

What is the definition of MAC?

Answer 44

The end-tidal concentration of anaesthetic agent (in %) that produces immobility in 50% of healthy middle-aged men when a one centimetre incision is made in their forearm.

Question 45

What does a higher MAC indicate about an anaesthetic agent's potency?

Answer 45

Less potent anaesthetic ## Footnote More is needed for the same effect.

Question 46

What does a lower MAC indicate about an anaesthetic agent's potency?

Answer 46

More potent anaesthetic ## Footnote Less is needed for the same effect.

Question 47

What is the MAC of Sevoflurane?

Answer 47

1.8%

Question 48

What is the MAC of Desflurane?

Answer 48

5%

Question 49

What is the MAC of Nitrous oxide?

Answer 49

105% ## Footnote Indicates that a very high concentration is required for immobility.

Question 50

What does MAC technically represent?

Answer 50

Blunting of the spinal cord reflexes ## Footnote It does not indicate a lack of awareness.

Question 51

At what percentage of an agent's MAC is awareness virtually unheard-of?

Answer 51

More than 70%

Question 52

If you run half a MAC of nitrous oxide and half a MAC of sevoflurane, what will be the result?

Answer 52

Achieve the same depth of anaesthesia as the full MAC of either agent.

Question 53

What is total intravenous anaesthesia commonly abbreviated as?

Answer 53

TIVA

Question 54

What type of infusion is primarily used in TIVA?

Answer 54

Propofol target-controlled infusion (TCI)

Question 55

List three pros of using propofol in TIVA.

Answer 55

* Anti-emetic effects * Smoother emergence * No direct greenhouse gas emissions

Question 56

List two cons of TIVA.

Answer 56

* Patient wakes up (paralysed) if the cannula breaks * No way to measure blood concentration

Question 57

What is a significant environmental benefit of TIVA?

Answer 57

Less occupational exposure to fluranes