complications of conscious sedation Flashcards
what is flumazenil
- reversal drug for sedation
what are complications if cannulation
- venospasm
- extravascular injection
- intraarterial injection
- haematoma
- fainting
what is venospasm
- disappearing vein syndrome, vein collapses as you go in with cannula
- can be accompanied by burning feeling
- associate with poorly visible veins
management fo venospams
- worse with repeated attempts
- go fast, slow makes it worse
-weaer gloves before, or use hot water to dilate
what is extravascular injection
- drug placed in interstitial space
- pain, swelling
- delayed absorption. problem = could pversedate pt
management of extravascular injection
- good techniques, test with saline
- remove cannula, apply pressure, reassure
what is intraarterial injection
- pain on venipuncture as artery walls thicker
- red blod in cannula
- difficult to prevent leaks
- pain radiating distally from cannulation site
- loss of colour or warmth to limb, weakening pulse
management of intra-arterial injection
- palpate first to check no pulse
- monitor for pulse loss
- leave cannula in for 5 mins
- if no problems then remove
- if symptomatic, leave nd refer to hospital
what is haematoma
- extravasation of blood into soft tissues = big bruise
- due to damage to vein walls from poor technique or when removing cannula failed to apply pressure
- care with elderly pts
Management of haematoma
- good technique, pressure post-op
- initial ice pack, moist heat 20 mins in, consider hearing containing gel if severe
how to prevent fainting from cannulation
- anxiety related usually, try get pt to relax
- make sure pt has eaten
- can give IS to relax them enough
- topical skin analgesia can help
what are the complications of drug administration
- hyper-responders
- hypo-responders
- paradoxical reactions
- oversedation
- allergic reactions
- sexual fantasy
what are hyper-responders
- deep sedation with minimal dose
- care with titration needed = only 1mg increments after initial 5mg dose
- more common in elderly
what are hypo-responders
- little effect with large dose
- check cannula is in the vein
- some pts lie about feeling it
- can be due to a drug tolerance pt never told you about
what is the highest threshold for drug
- shouldn’t go over 10mg, BNF actually says 7.5mg
what are paradoxical reactions
- appear to sedate normally
- react extremely to all stimuli, then relax when stimuli removed
- check failure of LA
- don’t add more sedation, find another management technique
- more likely in younger pts
how to know if oversedated
- loss of consciousness, lose verbal contact, respirator depression, loss of ability to maintain airway (respiratory arrest)
what is the management of over-sedarion
- stop procedure and try rouse pt
- if not waking, start ABC
- if no response t stimulation and support, reverse with flumazenil 200µg then 100µg increments at minute intervals
- watch for 4 hours as flumazenil has a shorter half life than midazolam so pt can go back into sedation again
management of respiratory depression
- check oximeter
- need mechanical and clinical monitoring, don’t want it to drop below 90%
- ask pt to take deep breathe sometimes that’s enough
- give supplemental O2 through nasal cannulae at 2 litres per minute
- if not getting better, reverse
management of loss of airway control and/or respiratory arrest
- stimulate pt/assess consciousness
- maintain/clear airway
- ventilate pt
- reverse sedation
what to do if allergic reaction
- manage as if pt not sedated
- give IM adrenaline if need be
what not to do if allergic reaction
- don’t give flumazenil as it is also a benzodiazepine like midazolam so would not help
what is the maximum dose of nitrous oxide that can be given during sedation
- 70%
signs of nitrous oxide over-sedation
- pt discomfort
- lack of cooperatoin
- mouth breathing
- lots of giggling
- nausea
- vomiting
- LoC
what is a likely cause of over sedatoin
- can misjudge dose
- or may have needed to give more sedative to get the to sedate as so nervous, but now not as scared and so don’t need as much but you give same level so over sedate them
treatment of oversedation
- decrease nitrous oxide conc. by 5-10%
- reassure
- don’t remove nosepiece as can get diffusion hypoxia
what is diffusion hypoxia
- massive diffusion gradient as nitrous oxide in the body is much higher than outside, so the body wants to get rid of it quickly and rush ou, but that would stop any oxygen from getting into the body so need to gradually bring pt back to 100% O2 and stay there for 3-5 minutes to prevent that happening
what is common with over sedation
- vomiting
