IV sedation M9 Flashcards
What family of drugs does Midazolam belong to?
Benzodiazepines
What does Anxiolytic mean?
Reduces anxiety
What does Hypnotic mean?
Induces sleep
What does Anticonvulsant mean?
Reduces the risk of convulsive fit
What does Anterograde amnesia mean?
The patient may not remember treatment after the drug has been administered
What three concentrations can Midazolam be obtained in?
10mg in 5ml
10mg in 2ml
5mg in 5ml
What is the most common concentration of Midazolam in a dental surgery?
5mg in 5ml, reduces risk of over sedation
Midazolam binds to which receptors in the CNS?
Benzodiazepine receptors
Benzodiazepine receptors run parallel to which other receptors?
Gamma-aminobutyric acid (GABA)
Benzodiazepine enhances the effect of neurotransmitters on the GABA receptors leading the brain to do what?
Decreased brain activity
What is half-life?
The time it takes for plasma levels of the drug to drop in half
Name the two stages that form the Benzodiazepines half-life?
Alpha & Beta
What does the Alpha half-life do?
Distribution and redistribution - travels to the brain and then from the brain to other tissues in the body.
How long is the Alpha half-life?
4-18 minutes
What does the Beta half-life do?
Metabolism & Excretion (the body breaks down so it is no longer active, then removed from the body)
How long is the Beta half-life?
1-4 hours (can be longer for elderly/teens)
What is the standard dose of Midazolam with an ASA I?
Initial: 2mg over 30secs - monitored for 2 mins
Further: 0.5-1mg
What is the usual total dose for ASA I of Midazolam?
2.5mg-7.5mg
What is the standard dose of Midazolam for an elderly patient?
Initial: 1mg - 1.5mg over 2 mins
should not exceed 3.5mg
Why is midazolam not recommended for pregnant women?
Because the drug passes through the placental barrier and enters the fetal bloodB
Why is midazolam not recommended for children?
Due to the paradoxical effect (agitation, involuntary movements & hyperactivity)
Why would someone with a kidney or liver impairment possibly have issues during/after sedation?
May lead to a slower excretion rate, effects may be enhanced or prolonged
If a patient has an adverse reaction to Midazolam, due to a known benzodiazepine allergy, what would you do?
Administration stopped
Airway maintained
Oxygen provided
Adrenaline administered
What opiate is occasionally used in conjunction with midazolam to enhance the sedation effects?
Nubain / Nalbuphie
What is Nubians reversal drug?
Narcan
This drug inhibits the metabolism of Midazolam resulting in a prolonged effect?
Erythromycin
This supplement enhances the effect of Midazolam reducing the effect?
St Johns Wart
What drug is used for the treatment of over sedation?
Flumazenil
What is the maximum does of Flumazenil?
1mg
Flumazenil is obtained in which concentration?
500mcg in 5ml
How is Flumazenil titrated?
200 mcg over 15 seconds
further 100 mcg every minute
What is the normal dose of Flumazenil?
300 mcg - 600 mcg
What is the half life of Flumazenil?
50 minutes
Name two contraindications of Flumazenil?
Coronary heart disease
Epileptic patients on medication
What is Propofol?
Amnesic and hypnotic drug used to maintain general anaesthetic
How does Propofol work?
By strengthening the effect of the GABA to depress the CNS - does not use receptors directly
What concentration is Propofol obtained in?
200mg in 20 ml (white liquid)
What is the half-life of Propofol?
2-24 minutes with 5 min recovery time
How is Propofol given to the patient?
Electronic fusion pump, at intervals. Too painful to push through smaller veins
Name the three contraindications of Propofol?
Patients taking respiratory depressants
Pregnancy/Nursing
Egg allergy
What is Eve sign positive?
The patient is unable to touch their nose
What is Eve sign negative?
The patient is able to touch their nose
How quickly does the patient reach stage IV, after the drug has been administered?
approx. 1 hour
What is the phase of sedation when the drug within the brain is at its highest? What are the effects?
Phase I
Behaviour changes
Slurred speech
Unaware of surroundings
What is the phase of sedation when the drug in the body starts to decrease, which is caused by the redistribution of the drug within the body?
Phase II
Patient becomes more aware
Amnesic effect decreases
What is the phase of sedation is it when the patient will appear relaxed and begin to feel normal?
Phase III
Patient will not be anxious
Anxiolytic effect still present
What is the phase of sedation when the patient will appear recovered? But only the Alpha half-life has occurred.
Phase IV
Amnesic effect has been know to last until this phase.
