Complications of Sedation Flashcards
concentration of midazolam used for IV sedation
1mg/1ml midazolam concentration
used due to National Pt Safety Agency report into reducing risk of midazolam overdose injections
2 categories of complication for IV sedation
complications during cannulation
complications during drug adminstration
5 complications during cannulation
- Venospasm
- Extravascular injection
- Intraarterial injection
- Haematoma
- Fainting
5 complications during drug administration
- Hyper-responders
- Hypo-responders
- Parodoxical reactions
- Oversedation
- Allergic reactions
what is venospasm
Disappearing vein syndrome
- Veins collapse at attempted venepuncture
May be accompanied by burning
Associated with poorly visible veins
management of venospasm
- Time dilating vein
- Tourniquet on and tap vein
- Worse with repeated attempts
- Efficient technique (smooth)
- Slow skin puncture makes worse
- Warm water / gloves in winter
what is extravascular injection
active drug placed into interstital space
dx for extravascular injection
pain
swelling
potential problem due to extravascular IV injection
delayed absorption
2 prevention strategies of extravascular IV injection
- Good cannulation
- Test dose of saline
- Flush before
- If get pain/swelling – reposition
3 tx for extravascular IV injection
- Remove cannula
- Apply pressure
- Reassure
what is intra-arterial injection when trying to do IV sedation
- Cannula into brachial artery
- Not superficial, unlike veins
dx intra-arterial injection
- Pain on venepuncture
- Red blood in cannula (oxygenated)
- Difficult to prevent leaks (under pressure too so will bubble)
- Pain radiating distally from site of cannulation
- Loss of colour or warmth to limb / weakening pulse
2 prevention strategies for intra-arterial injection
- Avoid anatomically prone sites- ACF Medial to biceps tendon (lateral to tendon)
- Palpate before attack – pulse? Not vein
3 management strategies for intra-arterial injections
- Take cannula out and Apply pressure for 5mins, stop bleeding - OK
- Check for loss of pulse
- Cold
- Discolouration
- Leave cannula in situ for 5 mins post drug (notice after giving drug)
- No problems – remove
- Symptomatic leave & refer to hopspital (procaine 1%)
what is haematoma due to IV sedation
- Extravasation of blood into soft tissues
- Due to damage to vein walls
- At venepuncture
- Poor technique
- Removal of cannula
- Failure to apply pressure
- Care with elderly patients
3 ways to prevent haematoma during IV sedation
- Good cannulation technique
- Avoid multiple holes in vein wall
-
Pressure post operatively
- Operator not pt
- Care with elderly
tx strategies for haematoma
Time
Rest
Reassurance
If severe
- Initial ice pack
- Moist heat 20mins in hour after 24hours
Consider heparin containing gel
how can fainting occur during IV sedation (venopuncture)
- Anxiety related to venepuncture
- Worse if starved
4 prevention strategies for fainting during venopuncture
- Don’t starve patients
- Topical skin anaesthesia
- RA First – easier to get legs up
- Position of patient
what are hyper-responders to IV sedation
- Deep sedation with minimal dose
- 1-2mg midazolam
prevention of hyper-responders to IV sedation
care with titration
1mg increments
slow titration in elderly esp
hypo-responders to IV sedation
little sedative effect with large doses
management of hypo-responders to IV sedation
- Check cannula in vein!!
- May be due to tolerance
- BZD induced
- Cross tolerance
- E.g. not told you about a drug habit they have (cocaine, benzo habit)
- Idiopathic
Threshold to abandon??
- 10mg common in dentistry
- BNF 7.5mg
paradoxical reactions to IV sedation
Appear to not sedate normally
Or sedate normally but React extremely to all stimuli
- Relax when stimuli removed
- Don’t remember what caused it as midazolam gives amnesia
management for paradoxical reactions to IV sedation
- Check for failure of LA
- DO NOT GO ON ADDING SEDATIVE
- Find other management technique
- Watch immature teenagers
- More likely in younger individuals
4 signs of oversedation
- Loss of responsiveness
- Respiratory depression
- Loss of ability to maintain airway
- Respiratory arrest
management of oversedation
4 points
- Stop procedure
- Try to rouse patient
- Alert – voice, pain or unresponsive
- Breathing
- Circulation
- If no response to stimulation and support (as soon as Alert failed)
- Reverse with flumazenil 200mg then 100mg increments at minute intervals
- Watch for 1- 4 hours
- Flumazenil has shorter half life than midazolam
- Be more careful next time
management of respiratory depression
4 points
- Check the oximeter (not in isolation check with how they look)
- Stimulate patient
- Ask to breathe
- Supplemental oxygen
- Nasal cannulae 2 litres per minute
- Reverse with flumazenil
- If sats drop below 90% and not rising
5 management points for loss of airway control and/or respiratory arrest
- Stimulate the patient / assess consciousness
- Maintain / clear airway
- Ventilate the patient
- Reverse sedation
- Consider other medical incident
allergic reactions in IV sedation
Rare to sedatives
- Remember Latex and elastoplast involved
Do not use flumazenil
- Benzodiazepine like midazolam – could make it worse, if unknown cause
Manage as if not sedated – advantage of IV access
- Give IM adrenaline
- A B C check and go for help
sexual fantasy due to IV sedation management
- No idea of incidence or aetiology
- No idea how to prevent
Ensure chaperoned!!!
reversal drug for midazolam
flumazenil
2 complications due to IHS
oversedation
pt panics
very safe machine has
- max dose built in (hypoxic rare as unable to give 100% N2O)
- cut off
oversedations with IHS can occur how
initally
later
Initially
- Misjudge dose
Later
- Traumatic procedure over
- E.g. needle phobic, so high level to give LA but that’s happened, pt more relaxed now but still at high level which is too high now so OD
- Mouth breathing ceases
- Adjust fit so concentration is higher suddenly
- Technical problem
- Adjust fit so concentration is higher suddenly
7 signs and symptoms of N2O overdose
- Patient discomfort
- Lack of co-operation
- Mouthbreathing
- Giggling
- Nausea
- Vomiting
- Loss of consciousness
3 points for tx of N2O overdose
- Decrease N2O concentration by 5-10%
- Reassure
-
Don’t remove nosepiece
- Diffusion hypoxia
- If get really panicked can give them 100% O2 through mask but need to keep nosepiece on for 3-5mins
- Diffusion hypoxia
pt panics during IHS
why?
- Have you used the correct sedation technique?
- IHS light sedative, may not be enough for them
pt panics during IHS
management
Reassurance
If cannot cope with sedation abort
complications with oral/transmucosal sedation
same as IV sedation
undersedation in transmucosal sedation management
place cannula and top up with IV
