Local Anaesthetic: Revised & Condensed Flashcards
Tissues that have the greatest to least vascularity for LA?
BICEPSS
Blood/Tracheal
Intercostal
Caudal and para “cervical”
Epidural
Perivascular brachial plexus
Sciatic/Spinal
Subcutaneous
From notes
IV > tracheal > intercostal > caudal > epidural > brachial > sciatic > s.c
Esters Metabolised?
Plasma cholinesterase’s to
inactive compounds
Amides Metabolism?
In liver hepatic cytochromes
CYP450
In which form is LA in its ionised form?
Water solubility of a LA is greatest in its ionised form
How are La injectable preparations formulated as?
Injectionable preparations are formulated as HCL salts
How do you increase speed of action?
Increasing alkalinity of injection solution increases the speed of action
La Systemetic toxicity?
SAMS
Slurred Speech(Parathesis)
Altered Central Nervous System(Arrhythmias)
Muscle Twitching(Tremors)
Seizures(Respiratory & cardiac arrest)
- Slurred Speech(Parathesis)
-Parathesias
-Numbness of lips/tongue - Altered Central Nervous System(Arrhythmias)
-Drowsiness
-Dizziness
-Arrhythmias
-Restlessness
-Confusion - Muscle Twitching
-Tremors - Seizures
-Respiratory & cardiac arrest
-Convulsions
-Respiratory depression
-Respiratory and cardiac arrest
What is the treatment for LA induced seizures?
Benzodiapines thiopentone
What is the treatment for LA induced reduced level of consciousness?
Oxygen
What is the treatment for LA induced hypotension?
Vasopressors
-Ephedrine/Phelephrine
-Inotropes/Adrenaline
What is the treatment for LA induced ventricular fibrilation?
Intralipid infusion
How to prevent LA toxicity?
Use max safe dose
Aspirate regularly during injection
Adrenaline if appropriate
Test doses
Stabilise needle carefully
Monitor patients vitals
Infiltration LA?
Infiiltration in the RMBL
Ropivacaine
Mepivacine
Bupivacaine
Lignocaine
Bupivacaine
Ester/Amide
P/K(LA & DOA)
I
M
Toxcity
Amide
P/K:Long-acting LA {doa usually 3 hours, peripheral blocks: 2-24hrs: dose & site}
I: Local infiltration, regional block, spinal & epidural anaesthesia
Chiefly used for surgical anaesthesia
M: Liver
Toxcity: Cardiotoxic
Which drug has a better CV safety profile then bupivacaine?
Levobupivacaine
-S-enantiomer of bupivacaine
Lignocaine
Ester/Amide
P/K(LA & DOA)
I
M
DI
Amide
Indications:
-Mostly used in dental practise
- Local/topical
- Infiltration
- Intravenous regional anaesthesia (biers block)
- Epidural anaesthesia
P/K: Rapid onset of action & Intermediate duration
CI:
Heart block/conduction disturbances
M: Liver hepatic Cytpchromes
DI: Cimetidine/Beta Blockers & NMB
Ropivacaine
Duration
Cautions
Indications
Metabolism
D: Long-acting LA
C: partial or complete
heart block, elderly, liver dysfunction
I: Epidural anaesthesia, local nerve block, infiltration & analgesia
M: Liver enzymes
Mepivacaine
Uses
Duration of action
Indications
Uses: Used in dental practice
DOA: Intermediate acting
Indications: Infiltration and nerve blocks
Metabolism: Liver Enzymes
Peripheral Nerve Blocking LA’s?
RMBL
Ropivacaine
Mepivacaine
Bupivacaine
Lignocaine
Central Nerve Block?
RBL
Ropivacaine
Bupivacine
Lignocaine
Articaine
Amides/Ester?
Indications?
P/K?
Solubility?
Uses?
Frequency of formulation?
Amides
I: Infiltration & Nerve Blocks
P/K: Amide but with ester side chain, High lipid solubility, Rapid onset
Uses: Dental & Periodontal
Ester drugs & M?
BOT ( Esther is a beaut/BOT)
Benzocaine
Oxybuprocaine
Tetracaine
M: Plasma cholinesterase
Amide drugs & M?
LAB MRP
Lignocaine
Atricaine
Bupicaine
Mepivacine
Ropivacine
Prilocaine
M: CYP450 Liver Cytochrome
Topical Anaesthesia?
BOLT P
Benzocaine
Oxybuprocaine
Lignocaine
Tetracaine
Prilocaine
