Emergency Drugs Flashcards
1
Q
What is phenylephrine?
A
- Alpha 1 agonist
- mostly directly acting
- venoconstriction >arterial constriction
- less potent than NE
- Longer lasting
- treat hypotension in OR
- Increases MAP, SBP, DBP, SVR
- Decreases HR, CO
- barorecptor mediated drop in HR
2
Q
Dose of phenylephrine?
A
- 50-200 mcg IV
- continuous infusion 20-50 mcg/min
- Standard concentration in vial 10 mg/mL
- Standard concentration for admin
- 100 mcg/mL
- Needs double dilution or in 100 mL NS
- Doublt dilution: mix 9 mL saline with 1 mL 10mg/mL phenyl, discard 9 mL, draw up new 9mL NS
3
Q
Overview of ephedine?
A
- Synthetic non-catecholamine
- indirect acting- stimulates B and alpha adrenergic receptors
- treat hypotension in OR due to various reasons
- CV effects similar to epinephrine, longer lasting
- SVR effected minimally
- CV effects mostly due to increased contractility
- increased map, sbp, dbp, hr, coronary bf
- Decreased renal, splanchinic BF
- (if you’ve given whole syringe, it’s time to move on)
4
Q
Dose of ephedrine?
A
- Dose 5-25 mg IV
- Tachyphylaxis is common with this agent- due to indirect effect and occupying of receptors
- Dilute once
- 1mL of 50 mg/mL + 4 mL saline= 10 mg/mL
- 1 mL of 50 mg/mL in 9 mL saline= 5 mg/mL
5
Q
Atropine overview?
A
- Anticholinergic-antagonizes effect of ACh at cholinergic post ganglionic muscarinic receptors
- Muscarinic receptors are present in heart, salivary glands, smooth muscle of GU and GI tract
- No/minmal effect at nicotinic receptors
- tertiary amine- naturally occuring, alkaloid of belladonna plant
- resembles cocaine in structure, has mild analgesic activity
- combines reversibly with muscarinic receptors and prevents ACh from binding to thses sites
- competitive inhibitors
6
Q
Dose of atropine? Side effects?
A
- Drug of choice for treatin intra op bradycardia
- 2 standard concentrations
- Dose:
- 15-75 mcg/kg IV
- 0.4-1 mg (max dose 3 mg)
- Other effects
- antisialagogue, bronchodilation, mydriasis, decreased GI motility and acid production, bronchodilation, sedation
7
Q
What is glycopyrrolate
A
Robinul
- Similar to atropine
- Quaternary ammonium- does not easily cross BBB so no sedative effects
- Usees similar to atropine, similar effects, more potent antisialagogue, less potent increase HR
- Dose: 0.2-0.4 mg IV
- Combine with AChe drugs for reversal (0.05-0.07 mg/kg)
- 1 cc of robinul for each cc of reversal drawn
8
Q
What is lidocaine?
A
- Amide local anesthetic
- Prevents transmission of nerve impulses by inhibiting the passage of sodium ions through voltage gated sodium channels in nerve membrane
- slows rate of depolarization such that the threshold potenital is not reached, and longer action potential is not propagated
- In cardiac conduciton and myocardial muscle reduces intracellular sodium activity and intracellular Ca activity
- reduction of arrhythmogenic transient depolarization
- reduction of contractility by decreasing inward sodium current
- Overdose can cause CNS toxicity/sz
9
Q
Dose for lidocaine?
A
- Used for local anesthetic activity
- numbness of veins for propofol (30mg) and ablating response to laryngoscopy (1mg/kg)
- Used as anti-dysthmic- suppresses ventricular dysrhythmia
- 2mg/kg followed by infusion 1-4 mg/min
10
Q
What is succinylcholine
A
Depolarizing muscle relaxant
- Attaches to alpha subunits of nicotinic cholinergic receptor and mimic action of ACh, depolarizing the post junctional membrane
- hydrolysis of SCh is lsower than ACh resulting in sustained depolarization of receptor ion channels
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11
Q
Dose succinylcholine? DOA, used for? Causes?
A
- Dose 0.5-1.5 mg/kg
- DOA 3-5 min
- Used for emergency airway situations (0.5 mg to break laryngospasm)
- RSI 1-1.5 mg/kg
- Can cause: dysrhtyhmia (bradycardia, arrest- acts at cardiac muscarinic receptors mimics ACh, hyperkalemia, myalgias, increase GI pressure, ICP nad IOP
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12
Q
Overview labetalol?
A
- Non selective beta blocker as well as alpha blcokade
- B: alpha 7:1
- Bolus of 10 mg typical
- can repeat in 10 min
- HTN emergency IV dose 40-80 mg
- DOA 2-18 hrs
- Make sure pt has adequate HR, do not give to asthmatics
13
Q
What is esmolol/
A
Beta 1 selective agent at small doses
- Onset 2 min
- E1/2 t 9 minutes
- metabolized by non-specific plasma esterases found in cytosol of RBC
- Bolus dose 500 mcg/kg
- in OR, typically 10-15 mg then dose according to resposne
14
Q
When should we be cautious with administration of succinylcholine?
A
- Especially cautious in paralyzed pt because they can have upregulation of ACh receptors, so admin of succinylcholine can cause hyperkalemia from efflux of K from cell.
- Caution in renal disease
- caution in children- chance of undiagnosed muscular dystrophy
15
Q
Important emergency drugs to alway have ready to go on cart
A
- Succinylcholine
- atropine
- ephedrine
- phenylephrine
- optional
- IV lidocaine
- LTA
- pt speicifc pre meds
- preop sedation/meds
- induction agent
- NMB agent
- narcotics needed during case
- abx per surgeon request
