IV key points

Question 1

ideal agent

Answer 1

anxiolysis
non-irritant
no SEs
sedation
quick onset
ease of administration
quick recovery
low cost

Question 2

BZD action

Answer 2

acts on receptors in CNS to enhance effect of GABA (inhibitory CNS neurotransmitter)
- prolongs time for receptor repolarisation

Question 3

effects of BZDs

Answer 3

respiratory - resp depression
CNS - CNS depression and muscle relaxation
CV - reduce bp by muscle relaxation, increase hr due to baroreceptor reflex compensating for bp fall

Question 4

SEs of BZDs

Answer 4

drug interactions
tolerance and dependence
- shouldn’t see in single session
sexual fantasies (rare)

Question 5

disadvantages of diazepam as a sedation agent

Answer 5

pain on injection
long recovery
risk of rebound sedation
unpredicatble

Question 6

midazolam prep

Answer 6

5mg/5ml (1mg/ml)

Question 7

advantages of midazolam

Answer 7

painless on injection
more rapid onset
more potent than diazepam
 - less working time but safer
extra-hepatic metabolism in bowel so less affected by liver disease than some
quicker recovery
reliable

Question 8

sedation team

Answer 8

operator - sedationist
2nd trained person e.g. nurse
= neither can leave room
3rd person - runner and reception

Question 9

roles of nurse

Answer 9

calm support
chaperone
pre and post op instruction
machine safety checks
monitoring
recovery
emergencies

Question 10

role of cannula

Answer 10

deliver sedative agent

Question 11

why is an indwelling cannula mandatory?

Answer 11

may be needed for emergency

more secure, rarely blocks

Question 12

why shouldn’t a butterfly cannula be used?

Answer 12

used for taking blood - one quick use
easy but clots and obstructs
easily dislodged

Question 13

flashback

Answer 13

bit of blood comes back into reservoir of cannula

shouldn’t be much resistance

Question 14

advantages of dorsum of hand

Answer 14

accessible
superficial and visible
no nearby arteries/nerves/joints

Question 15

disadvantages of dorsum of hand

Answer 15

poorly tethered - move about a bit
affected by peripheral vasoconstriction so may need to warm hand
small veins
more painful

Question 16

antecubital fossa - where should you keep?

Answer 16

lateral to biceps tendon

Question 17

advantages of antecubital fossa

Answer 17

larger veins, better tethered to CT
more predictably sited
less painful
less venoconstriction

Question 18

disadvantages of antecubital fossa

Answer 18

access, joint immobilisation
potential nerve damage/intra-arterial injection
less stable

Question 19

pre-sedation process

Answer 19

Ametop gel
pre-op pulse and bp
confirm
 - escort
 - travel home
 - responsibilities
 - reconfirm consent
get high vol aspiration set up
emergency drugs ready
 - flumazenil
 - means of ventilation

Question 20

what should be done with the cannula before sedation?

Answer 20

flush with saline

Question 21

midazolam dose

Answer 21

2mg bolus

1mg increments every 60s until suitable level of sedation

Question 22

suitable sedation signs

Answer 22

slurring and slowing of speech
relaxed
delayed response to commands
willingness to accept tx
Verrill's sign
Eve's sign

Question 23

Verrill’s sign

Answer 23

ptosis - drooping eyelids

Question 24

Eve’s sign

Answer 24

loss of motor coordination

- get pt to close eyes, arms out wide then touch nose with both fingers, often miss nose

Question 25

therapeutic dose of midazolam varies with:

Answer 25

sleep
alcohol
stress
drugs

Question 26

max midazolam dose

Answer 26

7.5mg generally, usually a lot less

Question 27

how long useful sedation for tx do you get with midazolam?

Answer 27

30-45mins

Question 28

flumazenil prep

Answer 28

500mcg/5ml

Question 29

flumazenil dose

Answer 29

200mcg then 100mcg increments every 60s until a response is seen
don’t give too quickly as pt may become v agitated

Question 30

flumazenil cautions

Answer 30

shorter 1/2 life than midazolam so risk of resedation
- keep pt for longer - 1-4hrs
caution in suspected BZD allergy

Question 31

recovery

Answer 31

escort 2nd person
60mins after last increment
continue monitoring (keep cannula)
 - write down times you give everything
remove cannula (warn bruising)
ensure can walk unaided
give escort POIs

Question 32

respiratory depression management

Answer 32

Stop tx
deep breaths (low 90s) - talk, shake, hurt
O2 - 2l/min via nasal cannulae
 - can continue tx with this in if O2 sats improve
O2 - 5l/min via Hudson mask
flumazenil (<90%)
ambu bag
airways