Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
24 Cards in this Set
- Front
- Back
|
Order of nerve blockade
|
B Autonomic; decreased BP
C Temp., Dull pain A d Sharp pain A g Muscle tone A b Touch A a Motor, then Proprioception |
|
|
Purpose of adding HCO3 to LA?
|
Alkalinization increases % of non-ionized LA speeding onset
|
|
|
3 things you need to know to determine if majority of drug is in non-ionized or ionized form
|
1 If drug is an acid or a base
2 pKa of the drug 3 pH that the drug is going into |
|
|
which part of the LA is lipophlic?
Which part is hydrophilic? What is the other part of the structure? |
The benzene ring is lipophilic
The quat. amine group is hydrophilic. The hydrocarbon chain is what makes the LA an ester or an amide |
|
|
Purpose of adding epinephrine to LA?
|
Vasoconstriction results in decreased absorption & increased duration by preventing washout. Also decreases systemic toxicity due to slower absorption.
|
|
|
Chlorprocaine trade name, class, pKa, onset, duration, & use, concentration
|
Nesacaine, Ester, 9.0, fast, short, epidural & peripheral blocks, low toxicity allow use of high (>3%) conc. to speed onset
|
|
|
Cocaine class, pKa, & use
|
Ester, 8.7, topical
|
|
|
Procaine class, & pKa
|
Ester, 8.9
|
|
|
Tetracaine trade name, class, pKa, duration, & use, preparation
|
Pontocaine, Ester, 8.2, longest of all spinal agents, Spinal & axillary blocks, mix with sterile water for hypobaric spinal perineal(prone/jackknife) cases
|
|
|
Metabolism of esters
|
Plasma pseudocholineterase, forms PABA which may cause allergic reactions
|
|
|
Metabolism of amides
|
Hepatic amidases, not borken down to PABA, but have PABA as preservative. Do not use with allergy to LAs
|
|
|
Dibucaine trade name, class, pKa,
|
Nupercaine, amide, 8.8, used to diagnose psudocholinesterase deficiency
|
|
|
Bupivicaine trade name, class, pKa, & use, max dose, adverse effects
|
Marcaine, amide, 8.1, infiltration, neuraxial & peripheral blocks, max dose 2-3 mg/kg, no conc. over 0.5% due to unresuscitatable collapse, small therapeutic window/cardiotoxicity is a concern
|
|
|
Benzocaine class, & use, adverse effects
|
amide, used in sprays, can cause methemoglobinemia, treat with methylene blue 1-2 mg/kg IV
|
|
|
Ropivicaine trade name, class, pKa, onset, uses
|
Naropin, amide, 8.1, similar onset to bupivicaine (marcaine), causes vasoconstriction(as cocaine), popular in OB because motor is spared, max dose of 2-3 mg/kg, similar to bupivicaine but is not an s-isomer
|
|
|
Lidocaine trade name, class, pKa, onset, duration, & use, concentration
|
Xylocaine, amide, 7.8, safer if IV due to higher toxicity ratio, max dose 5mg/kg plain, 7 mg/kg with epi, used for infiltration, topical, IV. Only LA given IV regularly to blunt resp. to intubation of min. pain from propofol inj.
|
|
|
Prilocaine trade name, class, pKa, adverse effects
|
Citanest, amide, 7.8, dose-dependent methemoglobinemia, cyanotic/chocolate colored blood, tx with methylene blue 1-2 mg/kg, spontaneous recovery after d/c prilocaine (citanset)
|
|
|
Etidocaine trade name, class, pKa
|
Duranest, amide, 7.7
|
|
|
Mepivicaine trade name, class, pKa
|
Carbocaine, amide, 7.6, used for axillary & peripheral blocks
|
|
|
1st sign of LA toxicity?
|
circumoral numbness
subjective, so you won't see this if under GA |
|
|
If under GA, 1st sign of LA toxicity?
|
Tachycxardia, HTN r/t excitatory effects
|
|
|
Stages of LA toxicity
|
1 CNS excitation - numbness, tinnitus, metallic taste
2 CV excitation -tchy, HTN 3 Late CNS symtpoms - shivering, twitching, siezures, LOC, apnea 4 Late CV symptoms - brady, hypotension, dysrhythmias, asystole |
|
|
Interventions for LA toxicity
|
Stop drug
Call for help 100% O2 Hyperventilate - raise siezure threshold, low CO2 causes vasoconstriction & decreases delivery of LA to brain Benzos/Barbs - raise siezure threshold |
|
|
Prevention of LA toxicity
|
Right dose/concentration of LA
Use test dose Monitor closely Benzodiazepines (Versed) on everyone to raise siezure threshold Epi as vascular marker to prevent intra-arterial injection |
