IV sedation

Question 1

What would you look for in an ideal IV sedation agent

Answer 1

anxiolysis
sedation
ease of use
Non-irritant
Quick onset
Quick recovery
No side effects
Low cost

Question 2

What is Benzodiazepines method of action

Answer 2

Acts on receptors in CNS to enhance effect of GABA (gamma-amino butyric acid)
prolongs time for receptor repolarisation

Mimics effects of glycine on receptors

GABA = cerebral cortex and motor circuits
GABA = inhibitory CNS neurotransmitter
Glycine = brainstem and spinal cord
All active BZD’s have benzene ring allowing attachment to receptors

Question 3

What are the effects of BZD,s

Answer 3

Respiratory Depression
-CNS depression and muscle relaxation
-Decreases cerebral response to increase CO2
-Synergistic relationship with other CNS depressants
-Increases respiratory depression in already compromised patients

Cardiovascular
-Decrease BP by muscle relaxation decreasing vascular resistance
-Increase HR due baroreceptor reflex compensating for BP fall

Question 4

What Drugs does BZD interact with

Answer 4

Any other CNS depressant

Erythromycin

Antihistamines

Question 5

How long can you prescribe BZDs for

Answer 5

2 weeks

Question 6

Whats the gold standard of BZD’s

Answer 6

Midazolam

Question 7

Is Midazolam water soluble

Answer 7

Yes

Question 8

If a BZD is water soluble what does that mean

Answer 8

Its painless on injection

Question 9

What is the prep of Midazolam

Answer 9

5mg/5ml

pH 3.5

More rapid onset and 2-3 times more potent than diazepam

Question 10

What is the elimination half life of Midazolam and where is it metabolised

Answer 10

Elimination half life = 90 - 150 mins

Metabolised in liver but also Extra-hepatic metabolism in bowel so less affected by liver disease than some

Question 11

What cannulation is mandatory

Answer 11

In-dwelling cannula and may be needed for emergency

BUTTERFLY cannula not recommended

Question 12

Where are the cannulation sites and why

Answer 12

Dorsum of hand
-accessible
-superficial and visible
-poorly tethered

Antecubital fossa
-brachial artery and median nerve
-keep lateral
-second choice

Question 13

Whats essential doing sedation

Answer 13

High volume aspiration

Monitoring
-Pulse oximeter
-Non invasive BP measurements every 5-10 mins
-Acts as early warning system
-Allow intervention before emergency develops

Question 14

What is the emergency reversal agent

Answer 14

Flumazenil

Question 15

When administering drug what important

Answer 15

Give a 2mg bolus and observe for 1min to see how they respond before you give more and then give 1mg increments every 60s, don’t exceed 7.5mg

Question 16

What can you check to test sedation

Answer 16

Eves sign loss of motor cordination

Check for Verrills sign ptosis

Slurring and slowing of speech
Relaxed
Delayed response to commands
Willingness to accept treatment

Question 17

How long does sedation normally last

Answer 17

30-45 minutes of useful sedation

Question 18

If there is respiratory depression what do you do

Answer 18

Talk, shake, hurt

head tilt, chin lift, jaw thrust

O2 (2l/min via nasal cannuae)
O2 (5l/min via hudson mask)

Flumazenil

Ambu bag

Check airways

Question 19

What is the preperation of Flumazenil

Answer 19

500mg in fml

dose is 200mg then 100mg increments every 60s until response is given