Complications of LA Flashcards
(42 cards)
What are some examples of systemic complication of LA?
- psychogenic/stress
- interaction with other drugs
- cross infection
- allergy
- collapse
- toxicity
What is the most common type of LA complication?
psychogenic/stress complications
What is meant by psychogenic/stress complication? (examples)
- fainting
- palpitations
- cold swear
- restlessness
- excitation
- trembling
- weakness
What causes psychogenic/stress complications?
lack of oxygenated blood to the brain
What are some clinical features of psychogenic complications?
- lightheadedness
- pallor
- beads of sweat (lips, nose, temple)
- bradycardia
- nausea
- pupil dilation
How is a patient who experiences a psychogenic complication to LA managed?
- lay flat and raise legs
- loosen neck of clothing
- improve room ventilation
- sweet drink (might be caused due to lack of food)
What are some examples of drugs that can interact with LA?
- MAOI
- Tri-cyclics
- beta blockers
- non-potassium sparing diuretics
- cocaine

How common is a true allergy to LA?
very rare
What were LA allergies historically due to?
the latex bung (no-longer made from latex)
What are most LA allergies due to now?
the preservatives/antioxidant
What are the clinical signs of toxicity complications of LA?
- convulsions
- loss of consciousness
- respiratory depression
-circulatory collaps
always make sure you work out the max dose correctly
What LA’s should you avoid in pregnant women? why?
LA’s that contain oxtapressin (vasoconstrictor) as theoretically it could induce labour
What is the maximum safe does of LA based/calculated on?
a fit healthy adult
Each max dose calculation should be done on what basis for the p?
An individual basis
Toxic effects of LA can be reduced by using what technique?
Aspirating technique
What is the max safe dose of lignocaine ?
5mg/kg (check - might be 4.4)
What is the safe dose of 2% lignocaine in a 70kg man (cartridges)? [assuming max dose = 5mg/kg]
2% = 2g/100ml (2000mg/100ml) = 20mg/1ml
Each cartridge is 2.2ml so will have 44mg actuve component per cartridge
70kg x 5mg = 350mg
350mg/44 = approx 7 cartridges
What is the max dose of Mepivicaine 3% (plain - no vasoconstrictor) ?
3mg/kg
What is the max safe dose of Articaine with adrenaline ?
7mg/kg
What is the max dose of prilocaine with octapressin?
8mg/kg

What are the effects of adrenaline on the heart? What receptors on the heart does adrenaline bind to in order to produce these effects?
Increase in: -heart rate -force -output -excitability
Through Beta 1 receptors
What are the effects of adrenaline on blood vessels? (and therefore skin and muscle) What are the receptors?
- coronary dilation
- skin contraction
- muscle dilation
alpha beta-2
What are the effects of adrenaline on systolic, diastolic and overall blood pressure?
Systolic = increase Diastolic = decrease Overall = little effect
What are the effects of adrenaline on the lungs? What receptors are responsible?
Bronchial muscle relaxation
Beta 2 receptors