Complications of Sedation Flashcards
What were the adverse findings of the Rapid Response report?
Bolus sedation still used
Untrained seditionists
Incorrect doses given- incorrect labels/concentration
Reliance on flumazenil
What is the bolus technique?
this is where the drug is put in at one time rather than slowly and gradually by titration while checking regularly
What is the only concentration of midazolam used?
1mg/1ml
When should flumazenil be used?
Used in an emergency to reverse effect of midazolam only
Should not be used to speed up recovery
Should not be relied on with practitioners wrongly choosing to over-sedate patient on purpose
What is the ultimate complication of sedation?
Death
Extremely rare
Would be due abuse or excessive levels/incorrect doses of drug given
What are the complications of cannulation in IV sedation?
Venospasm
Extravascular injection
Intra-arterial injection
Haematoma
Fainting
What is venospasm? (disappearing vein syndrome)
Veins collapse at attempted venepuncture (Associated with poorly visible veins)
-> May be accompanied by burning
How is venospasm prevented?
Using tourniquet/vein tapping to help dilate vein
Gravity
Warm water/gloves
Quicker puncture
What occurs in an extra-vascular injection?
Active drug placed into interstitial space
-> Pain/swelling
-> can result in delayed absorption
How is EVI prevented?
Good cannulation
Test dose of saline (flush)
How is EVI treated?
Remove cannula
Apply pressure
Reassure
Which artery is most commonly affected by intra-arterial injection?
Brachial artery
What are the signs of an IA injection?
Pain on venepuncture
Red blood in cannula
Difficult to prevent leaks
Pain radiating distally from site of cannulation
Loss of colour or warmth to limb / weakening pulse (as artery could constrict and blood supply could be stopped)
How can IA injections be prevented?
Always stay superficial
Artery walls are thicker- puncture is thicker
Prevent by going lateral to bicep tendon
Palpate to check if vessel has pulse (if positive it is not a vein)
How is an IA injection treated?
Monitor for loss of pulse- Cold/Discolouration
Leave cannula in situ for 5 mins post drug
No problems – remove
Symptomatic- leave and refer to hospital (procaine 1%)
What can happen if diazepam is giving intra-arterially?
Necrosis
What is a haematoma?
Extravasation of blood into soft tissues (bruising)
-> Due to damage to vein walls
How are haematomas prevented?
Good cannulation technique- Avoid multiple holes in vein wall
Pressure on removal of cannula/post operatively
(Operator not patient)
Care with the elderly
How are haematomas treated?
Time, Rest, Reassurance
-> If severe- ice pack (initially), moist heat (20mins at a time)
-> Consider heparin containing gel
What are the main causes of fainting during venipuncture?
Being starved
Anxiety toward needles
How is fainting prevented?
Don’t starve patients
Topical skin anaesthesia
IS First- to relax patient
Position of patient- supine (allows legs to be raised)
What are the complications of drug administration in IV sedation?
Hyper-responders
Hypo-responders
Parodoxical reactions
Oversedation
Allergic reactions
What are the features of hyper-responders?
Deep sedation with minimal dose
-> 1-2mg midazolam
How can effect in hyper-responders be managed?
Care with titration
-> 1mg increments
-> Slow titration in elderly
What is the cause of hyporesponse to IV sedation?
Cannula in incorrect place- flush it again?
Patient may have cocaine/benzo habits (cross tolerance)
What is the max dose given to hypo-responder?
10mg then stop if not working
What are paradoxical reactions?
Patient does not sedate as expected:
Patient becomes more hyper instead of more sedate
Large reactions (screams) to stimuli such as high speed- check it is numbed properly
-> more common in immature teenagers
What should never be done in event of paradoxical reaction to IV sedation?
Add more sedative
-> find another management technique instead
What is over-sedation and its features?
Lose responsiveness
Respiratory depression- give oxygen and take deep breaths (usually)
Loss of ability to maintain airway
Respiratory arrest- BVM
How is over sedation managed?
Stop procedure
Shake patient/Shout
A B C
If no response to stimulation and support
-> Reverse with flumazenil 200mcg then 100mcg increments at minute intervals (Watch for 1- 4 hours)
How is respiratory depression managed?
Check the oximeter
-> If low 90s: Stimulate patient- Ask to breathe deeply
-> If below 90- Supplemental oxygen via Nasal cannulae (2 litres per minute)
->Reverse with flumazenil
How is loss of airway control/respiratory arrest managed?
Stimulate the patient / assess consciousness
Maintain / clear airway
Ventilate the patient
Reverse sedation
Consider other medical incident
What is done if there is an allergic reaction in IV sedation?
More likely to be to latex/elastoplast than sedative
-> do not use flumazenil to reverse (doubling up on benzos which patient may have allergy to)
-> manage as if patient not sedated- IM adrenaline and ABC
How are dentists/patients protected from sexual fantasy disclosure in IV sedation?
Having a chaperone present at all times
What are the complications of IS sedation?
Oversedation
Patient panics
What is the feature of IS machines which prevent hypoxia in the patient?
Max percentage of NO in mix is 70%
What are the causes of over sedation in IS
Misjudging dose
Traumatic part of procedure finished- patient relaxes but dose is not reduced
Mouth breathing- patient receives no effect due to this, then starts to breathe properly through nose and becomes overstated
What are the signs and symptoms of Nitrous Oxide overdose?
Patient discomfort
Lack of co-operation
Mouthbreathing
Giggling
Nausea
Vomiting
Loss of consciousness
How is over sedation in IS treated?
Decrease N2O concentration by 5-10%
Reassure
Don’t remove nosepiece (Diffusion hypoxia)- change to 100% oxygen
What is diffusion hypoxia and how is it prevented?
Diffusion Hypoxia- NO in lungs and bloodstream wants to rush out lungs and tissues into atmosphere (much smaller concentration than what patient is breathing)
-> When turning off keep oxygen on for 3-5mins
Why may a patient panic during IS?
Only light sedation- may not be enough for their anxiety level
-> reassure and remind them to keep breathing (if they cannot cope-abort)
What are the complications of oral and transmucosal sedation?
Same as IV
-> manage in the same way
-> if under-sedated top up with IV
