Anaesthesia

Front 1

What is narcosis?

Back 1

A state of unconsciousness

Front 2

Name some intravenous anaesthetics

Back 2

Propofol (quicker acting for day case surgery), Thiopentone (barbiturate-longer lasting), Etomidate (selective and stable and good cardiostability), Ketamine (NMDA receptor antagonist, causes dissociation, used in army field anaesthesia), Benzodiaepines

Front 3

Name some inhaled anaesthetics

Back 3

Ether/chloroform/halothane (all historical), isoflurane, sevofluarane, desflurane

Front 4

Whats the difference between depolarising and non-depolarising muscle relaxants?

Back 4

Depolarising bind to the nicotinic receptors very strongly, causing a massive depolarisation that quickly desensitises the receptors, non-depolarising block the agonist, acetylcholine from binding to the nicotinic receptor

Front 5

What are some examples of depolarising and non-depolarising muscle relaxants?

Back 5

depolarising: suxamthonium, non-depolarising: Atracurium, vecuronium, rocuronium

Front 6

Which laminae of Rexed is most linked to pain transmission?

Back 6

II. But the some of the others are involved to different degrees too

Front 7

What are the central effects of opioids?

Back 7

Analgesia, sedation, euphoria, Respiratory depression, anti-tussive, nausea and vomiting, pupillary constriction

Front 8

What are the peripheral effects of opioids?

Back 8

Hypotension, increased sphincter tone and reduced gastric mobility, urinary retention histamine release, possible immunosepressant

Front 9

Name some endogenous opioid ligands

Back 9

Enkephalin, beta endorphin, and dynorphin

Front 10

Pros and cons of IM opioids?

Back 10

advantages: safe, inexpensive, nurse assessment

disadvantages: pharmacovariability, painful injection, breakthrough pain

Front 11

What are the side effects of spinal and epidural opioids?

Back 11

respiratory depression, urinary retention, big increase in itching, nausea and vomiting

Front 12

What percentage of oral opioids gets past first pass metabolism?

Back 12

30%

Front 13

Tell me about opioid excretion

Back 13

Converted to polar metabolites in the liver and exreted via the kidney. Hydroxyl groups are conjugated with glucuronide (morphine). Esteres are hydrolysed by esterases (pethidine), N-demethylation also occurs (methadone)

Front 14

What are neuromuscular blocking drugs used in surgery for?

Back 14

Tracheal ventilation, mechanical ventilation and surgery where muscle relaxation is required

Front 15

Are motor neurons long? Are they fast? Are they myelinated? What kind of conduction do they have?

Back 15

Long- some longer than 1 metre

very fast 50-100 metres per second

myelinated

saltatory conduction

Front 16

Do acetylcholine and neuromuscular blocking drugs need to occupy many or a few receptors respectively to produce their action?

Back 16

Acetylcholine only needs to occupy a few receptors to cause a muscle contraction, therefore NMBD need to occupy around 90%!

Front 17

How does suxamethonium work?

Back 17

two Ach molecules together, which each bind to a subunit, cause the channels to open and cause a massive depolarisation. Fasiculation then relaxation Has a rapid onset of 90 seconds then a rapid offset of 3-5 minutes thanks to plasma cholinesterases

Front 18

Talk to me about suxamethonium metabolism

Back 18

metabolised in the plasma by plasma pseudocholinesterase, usually complete within about 5-10 minutes but some patients lack tis due to difference in E1 genes. Can cause patients to be apnoeic for 1-2 hours

Front 19

Side effects of suxamethonium?

Back 19

muscle pains, increased intracranial pressure, hyperkalaemia, increased vagal tone (bradycardia), anaphylaxis, potential for prolonged apnoea, and can be a trigger for malignant hyperpyrexia

Front 20

What are the main classes of non-depolarising neuromuscular blocking agents?

Back 20

Benzylisquinolinium such as tubocurarine

aminosteroids such as verucuronium and rocuronium

Front 21

Benefits and downsides of atracurium?

Back 21

Developed in the 1980s, it is metabolised quickly with no cardiac effects, providing a safety net for patients particularly those with hepato-renal failure. However it does cause release of histamine causing itch, wheals, systemic hypotension and bronchospasm

Front 22

Why is vecuronium not used as much as atracurium?

Back 22

Takes longer for clinician to prepare! It is an amino steroid

Front 23

Tell me about rocuronium

Back 23

is a rapid onset analogue of vecuronium. Has a novel reversal agent called sugammadex