intravenous sedation Flashcards
Name 4 ideal properties of an IV sedation agent
Any from:
- anxiolytic
- sedative as a side effect
- easy to administer
- non-irritant
- has a quick onset
- has a quick recovery
- low cost
Describe the effects of benzodiazepines on the nervous system
Act on receptors in the CNS to enhance the effect of GABA
This prolongs the time for receptor repolarisation
They mimic the effect of glycine on the receptors
In which ways can benzodiazepines cause respiratory depression?
- CNS depression and muscle relaxation
- Decreased cerebral response to CO2
- Synergistic relationship with other CNS depressants
- Causes further respiratory depression in already compromised patients
What are the cardiovascular effects of benzodiazepines?
- Decreased BP by muscle relaxation which decreases vascular resistance
- Increased HR due to baroreceptor reflex compensatin for BP fall
Name 4 drug interactions with benzodiazepines
Any other CNS depressant eg - opioids
Erythromycin
Antihistamines
Alcohol
Name 3 other side effects of benzodiazepines
Tolerance
Dependance
Sexual fantasy
Name 4 disadvantages of diazepam as a sedative
Any from:
- pain on injection
- long elimination half life
- risk of rebound sedation
- long recovery
- unpredictable
What is the dose, and pH of midazolam used for sedation?
5mg/ml
pH 3.5
What is the onset and elimination half life of midazolam?
Rapid onset
90-150 minutes
Name 4 people involved in the sedation team?
Operator/sedationist
Second sedation trained person eg - dental nurse
Someone else in the practice for reception and as a runner
Patients escort present
What are the different cannulation sites for IV sedation?
Dorsum of hand
Antecubital fossa
What are the advantages of using the dorsum of the hand for a cannulation site?
Accessible
Superficial and visible
What are the drawbacks of using the dorsum of the hand for a cannulation site?
Poorly tethered
Affected by peripheral vasoconstriction so may need to warm up hand
How much midazolam is administered at a time?
2mg bolus, then 1mg increments every 60 seconds until suitable level of sedation
Give 4 ways you can tell if a sedated patient is ready to start treatment?
Any from:
- they are willing to start treatment
- relaxed
- delayed response to commands
- slurring and slowing of speech
- Verrill’s sign of ptosis
- Eve’s sign - loss of motor coordination
What is the maximum dose of midazolam generally recommended?
7.5mg
How long is a patient likely to be sedated for with midazolam?
30-45 minutes
What are the recovery steps after IV sedation?
Escort can be with the patient
60 minutes after last increment of midazolam
Cannula needs to be removed before leaving
Ensure patient can walk unaided
Escort given post operative instructions
What should you do if the patient goes into respiratory depression during IV sedation
Talk to the patient and shake them
Head tilt, chin lift, jaw thrust
Oxygen 2L per minute via nasal cannulae
Oxygen, max you can give vis Hudson mask
Flumazenil
Call and ambulance
What is the dose of flumazenil and how much is given?
500mcg in 5ml
Dose given is 200mcg (2ml) then 100mcg (1ml) every 60 seconds until a response is seen
What is the risk of flumazenil?
Re-sedation
What is the elimination half life of flumazenil?
50 minutes
