IV Sedation III Flashcards
What is midazolam?
Benzodiazpine
Clear, colourless and isotonic solution
pH of midazolam?
3.3 - acidic, not painful on infection
How do benzodiazepine work?
Enhance inhibitory action of GABA in CNS
Benzodiazepine potentiate GABA by increase Cl ion into cell - decreasing ability to initiate action potential
Where do benzodiazepine bind?
GABA A receptor
Diff of GABA A vs GABA B?
A - modulated by other recoptors
B = skeletal muscle role
Modulation GABA A?
Opening receptor channels = Cl influx
Effects of benzodiazepine
SAD AAH
Sedative Anxiolytic Decrease muscle tone Anticonvulsant Amnesia Hypnotic
How long should pt stay after sedation?
Min 1 hour last dose of sedative
Onset of action of midazolam?
IV = 3 minutes
What factors increase half life of midazolam?
Age - elderly
Sepsis
Poor renal function
Additional effects midazolam?
Decrease ventilatory response
Decrease mean arterial pressure
Reduction cerebral blood flow
Contraindication giving midazolam?
Allergy
Myasthenia gravis - due muscle relaxation can cause respiratory depression
Signs midazolam overdose?
Over sedation
Confusion
Diminished relfex
Decreasing vital sign
How to tx midazolam overdose?
Stop midazolam
Oxygen
Flumazenil
What dose of flumazenil should be given?
200-600ug IV
Competitive inhibitor of midazolam
Why is there a risk of re-sedation once given flumazenil?
Difference in half life - rare to happen
How to titrate midazolam?
Slow titration of 2mg
Wait 90 sec and re-assess before giving 1mg more until desired sedation
Requirement of pt preparation?
Pre-assessment: baseline obvs MH ASA assessment Written consent Pre-op instructions
What should do if get intra-arterial access?
If pre-drug remove cannula and apply pressure
Post-drug - leave cannula and contact local vascular surgeon
What are issues w/ cannulation?
Transfixation
Haematoma
Embolism
Monitoring required for IV sedation?
BP, HR and O2 sats
Vital signs
Why is LA required during sedation?
Midazolam doesn’t give clinical analgesia
What post-op should pt be aware of?
For 24 hrs should follow No driving/ operating machinery No alcohol or sedative drugsd Undertake no legal responsibility - work/ childcare Shouldn't be left alone Avoid social media
How dispose unused midazolam?
Should be witnessed
Occurrence of sexual fantasy w/ midazolam?
1 in 200 cases
