Intravenous Sedation Flashcards
How do benzodiazepines work?
Act on receptors in CNS to enhance effect of GABA, prolongs time for receptor repolarisation, mimics effect of glycine on receptors
What allows benzodiazepines to attach to receptors?
Benzene ring
What respiratory effects does IV sedation have?
CNS depression and muscle relaxation, decreases cerebral response to CO2
What cardiovascular effects does IV sedation have?
Decreased BP by muscle relaxation decreasing vascular resistance
Increased HR due to baroreceptor reflex compensating for fall in BP
Advantages of midazolam over diazepam
Painless, quicker onset, quicker recovery, more reliable, relatively cheap
What structures should you be aware of when using antecubital fossa to cannulate?
Brachial artery and median nerve
Dose of midazolam
2mg bolus (watch and see how they respond to this for a minute then start giving more)
1mg increments every 60 seconds
Increments until suitable level of sedation
Maximum dose - 7.5mg (most people fine with less - often 5mg fine)
Signs of sedation
Slurring and slowing of speech
Relaxed
Delayed response to commands
Willingness to accept treatment
Verrills sign-ptosis (can see this in cat pic -eyelids drooping)
Eve’s sign-loss of motor coordination (get patients to shut eyes and put arms out to side then try touch nose with finger - will often miss)
How might you notice respiratory depression (emergency)?
Drop in O2 saturation or not taking deep enough breaths
How would you manage respiratory depression?
Talk, shake, hurt Head tilt chin lift, jaw thrust O2 (2ml/min via nasal canulae) O2 (5ml/min via hudson mask) Flumazenil Ambu bag (bag valve mask)
How is the dose of flumazenil given?
200mcg then 100mcg every minute until response seen
What is risk with flumazenil/why does pt need to be watched for bit after?
Shorter half life than midazolam - risk of re-sedation
