Complications and Contraindications of LA Flashcards
What type of LA is lidocaine?
amide type
What is the concentration of lidocaine used and what is the concentration of vasoconstrictor?
Lidocaine = 2%
Adrenaline = 1:80000
What type of LA are prilocaine and articaine?
amide
What is the vasoconstrictor used with prilocaine?
felypressin (octapressin) 1.2micrograms
What is the concentration of articaine used?
4%
What are the systemic complications of LA that present as signs/symptoms?
fainting
palpitations
cold sweats
restlessness
excitation
trembling
weakness
What is the possible concentrations of adrenaline used with articaine?
1;100000
1;200000
1;400000
What is articaine better than lidocaine in?
infiltrations
fast onset, lasts longer
What is the cause of these systemic signs?
lack of oxygenated blood to brain due to vasoconstrictor
What drugs do LAs interact with?
M.A.O.I (adrenaline)
tri-cyclics (adrenaline)
b-blockers (adrenaline)
non potassium sparing diuretics
cocaine
What causes allergies in LAs mostly?
preservatives such as
methylparaben
sodium metabisulphite
What are the signs of toxicity?
convulsions
loss of consciousness
respiratory depression
circulatory collapse
How much lidocaine does each cartridge usually contain?
44mg
What should you avoid giving to pregnant people?
octapressin as this has the potential to induce labour
felypressin
What is the max dose of lidocaine, articaine, and prilocaine?
lidocaine = 4.4mg/kg
articaine = 7mg/kg
prilocaine = 6mg/kg
When should you be cautious giving adrenaline to a patient?
CVD
hyperthyroidism (thyroid crisis)
drug interactions
phaeochromocytoma (hypertension)
What drugs interact with adrenaline?
MAOI
tricyclic antidepressants
b blockers
non potassium sparing diuretics
halothane (general anaesthesia)
cocaine
What are complications that may occur local to injection site?
prolonged anaesthesia pain
trismus
haematoma
intra-vascular injection
blanching
facial paralysis
broken needle
infection
soft tissue damage
contamination
How can prolonged anaesthesia occur?
direct trauma from needle (multiple passes with the same needle)
chemical trauma for direct injection
What LA did most nerve injury come from?
articaine (4%)
What is the first line choice of LA?
2% lidocaine with adrenaline
How does trismus occur?
damage/irritation to medial pterygoid
What can you prescribe for trismus?
for profound cases =
anti-inflammatory
muscle relaxant
What is facial palsy?
unilateral motor nerve paralysis
What is the cause of facial palsy?
IANB into parotid gland too far posteriorly
What differentiates a stroke from a palsy?
stroke patients can wrinkle both sides of the forehead as upper motor neurons defects spare upper branches of facial nerve
What are the signs of intra-arterial injections?
skin blanching
visual disturbances
How to avoid intra-arterial injections?
aspirate
introduce drug slowly
