Clinical Flashcards
Describe the different ASA categories
1- normal, healthy
2- mild systemic disease
3- severe systemic disease
4- severe systemic disease that is constant threat to life
5- moribund patient not expected to survive w/o surgery
6- brain-dead (organ harvest)
What are some predictors of difficult airway?
history of difficult intubation, neck circumference >16 in (F) or >17 in (M), thyromental distance <7 cm, Mallampati 3 or 4
What are some predictors of difficult mask ventilation?
age >55, BMI >26, lack of teeth, beard, snoring
What is the MoA of propofol?
GABA agonist
What is the induction dose of propofol?
1-3 mg/kg
What is the maintenance dose of propofol?
75-300 mcg/kg/min
What is a pro of propofol (Diprivan)?
antiemetic
What are some cons of propofol?
accumulates in tissue with prolonged use, pain on injection, CV and respiratory depression, hypotension
What is the MoA of etomidate (Amidate)?
GABA modulation
What is the induction dose of etomidate?
0.2-0.6 mg/kg
What are some pros of etomidate?
minimal CV and respiratory depression
What are some cons of etomidate?
pain on injection, N/V, myoclonus, adrenal suppression
Does etomidate provide analgesia?
no- must combine with opioid or esmolol for laryngoscopy
What is the MoA of ketamine (Ketalar)?
NMDA antagonist
What is the induction dose of ketamine?
1-4.5 mg/kg (usually no more than 2 needed)
What is the maintenance dose of ketamine?
0.1-0.5 mg/min
What are some pros of ketamine?
minimal CV and respiratory depression, provides analgesia, several routes of administration
What are some cons of ketamine?
increases BP, HR, ICP, and SNS, post op dysphoria, hallucinations
Who would you avoid ketamine in? Who might you use it on?
Avoid in CAD, use in trauma
What is the MoA of dexmedetomidine (Precedex)?
alpha 2 agonist
What is a pro of using precedex?
minimal respiratory depression
What is the typical dosing of precedex?
1 mcg/kg followed by infusion of 0.2 mcg/kg/h
What are some cons of precedex?
no amnesia properties, can cause bradycardia
What is the MoA of barbiturates? (thiopental, methohexital)
GABA agonist
What is a pro of using barbiturates?
decreases ICP
What are some cons of barbiturates?
CV and respiratory depression, hypotension, porphyria, no reversal
What types of cases are barbiturates usually used for?
neurosurgery
What is the MoA of benzos?
GABA agonist
What is the typical dose of midazolam/Versed?
1-2.5 mg
What is the reversal agent for benzos?
flumazenil
What are some cons of benzos?
CV and respiratory depression, hypotension, post op delirium
In what type of patient may the half life of benzos be prolonged?
cirrhosis
What is the reversal agent for opioids?
naloxone
What is a typical dose of morphine?
2.5-5 mg IV every 3-4 hours
What is a pro of morphine?
long duration of action
What are some cons of opioids?
respiratory depression, hypotension, N/V, decreased GI motility, urinary retention, histamine release (morphine)
How is morphine excreted?
renally- renal failure may prolong action secondary to active metabolites
What is the most potent opioid?
sufentanil
What is the shortest duration opioid?
remifentanil
What is a typical dose of dilaudid?
0.2-1 mg
What is an advantage of using dilaudid over morphine?
no histamine release, 5x more potent
How do anesthetic gases work?
alters ACh, GABA, and glutamate receptor activity
What two gases cause bronchodilation?
iso and sevo
Which anesthetic gas can be used for induction?
sevo
How are anesthetic gases eliminated?
ventilation
Which anesthetic gas preserves renal, coronary, and cerebral blood flow?
isoflurane
Which anesthetic gas has the slowest onset and offset?
isoflurane
Which anesthetic gas has the quickest onset and offset?
desflurane
What are some pros of using nitrous?
decrease volatile anesthetic requirements, less myocardial depression, no odor
What are some cons of using nitrous?
diffuses into air filled spaces, increases pulmonary vascular resistance, decreases FiO2
What is the MoA of succinylcholine?
ACh receptor agonist causing persistent depolarization?
What is different about a depolarizing vs nondepolarizing block?
depolarizing has phase I (twitching and fasciculations) and phase II (flaccid paralysis) whereas nondepolarizers only have “phase II”
What is the induction dose of succs?
0.5-1.5 mg/kg
Who should you avoid succs in?
hyperkalemia, myopathies, burns, MH
What is the MoA of nondepolarizing NMBs?
ACh receptor antagonist
What is a standard induction dose of roc?
0.6-1.2 mg/kg (usually 0.5)
What is an induction dose of vec?
0.08-0.1 mg/kg
Ideally how many twitches do you want present during a case?
1-2
What is a typical dose of neostigmine?
0.03-0.07 mg/kg
What are some unwanted side effects of AChE inhibitors? How do we avoid them?
bradycardia, increased secretions, and bronchoconstriction- pretreat with anticholinergic
What is the typical dose of glyco when given with neostigmine?
0.2 mg per 1 mg of neostigmine
What do you give first during reversal, AChE inhibitor or anticholinergic?
anticholinergic
What is nicardipine and a typical dose?
CCB (lowers BP and peripheral vascular resistance)- 5 mg IV
What are some unwanted side effects of nicardipine?
N/V, tachycardia
Who would you avoid giving nicardipine in?
aortic stenosis
What does nitroprusside do?
decreases afterload and myocardial O2 demand
What is a typical maintenance dose of nitroprusside?
0.2 mcg/kg/min up to 10
What can an infusion rate of >2 mcg/kg/min of nitroprusside lead to?
cyanide toxicity, methemoglobinemia
What is esmolol and what does it do?
beta 1 antagonist- lowers chrono- and inotropic activity, fast acting
What is a typical dose of esmolol?
1 mg/kg over 30 seconds
What kind of conditions are esmolol contraindicated in?
2nd or 3rd degree heart block
What s/s may esmolol mask?
signs of hypoglycemia
Why would esmolol be preferred over other beta blockers in asthmatics?
minimal bronchoconstriction (beta selective)
What is labetalol and what does it do?
alpha and beta antagonist- decreases BP, HR, and CO
What is a typical dose of labetalol?
20-80 mg IV
Who would you avoid labetalol in?
obstructive airway disease, heart block
What is hydralazine?
short acting direct vasodilator
What is a typical dose of hydralazine?
1.7-3.5 mg/kg daily in 4-6 doses
What is an unwanted SE of hydralazine? Who would you avoid it in?
tachycardia; avoid in CAD and mitral valve disease
What is phenylephrine and what does it do?
alpha 1 agonist- increases SBP and MAP
What is a typical dose of phenylephrine?
50-100 mcg
What may be a reflex result of using phenylephrine?
bradycardia
What is norepinephrine and what does it do?
alpha and beta 1 agonist (a>b), increases MAP, constricts both arteries and veins and increases contractility
What is the typical infusion rate of norepinephrine?
0.01-3 mcg/kg/min
Vasoconstriction from using norepinephrine can decrease blood flow to?
renal, splanchnic and cutaneous
What is epinephrine and what does it do?
alpha and beta agonist- relaxes bronchial smooth muscle, increases HR and CO, dilates skeletal muscle vasculature
What is a typical infusion rate of epi for acute hypotension?
0.05-2 mcg/kg/min
What is a typical dose of epi for anaphylaxis?
0.2-0.5 mg IM
What does epi do to cardiac O2 demand?
increases (should not be used in cardiac shock)
What is dopamine and what does it do?
dopamine agonist at low doses, B-1 at medium, alpha at high- causes renal, mesenteric, coronary, and intracerebral vasodilation at low doses which increases RBF and GFR
What is a typical maintenance dose of dopamine for cardiogenic or septic shock?
5-10 mcg/kg/min
When is dopamine contraindicated?
pheochromocytomas
What is dobutamine and what does it do?
primary beta 1 agonist (some alpha and beta 2)- increases contractility and cardiac output
What is a typical maintenance dose of dobutamine for cardiac decompensation?
0.5-1 mcg/kg/min
Who should you not use dobutamine in?
hypertrophic cardiomyopathies
What is isoproterenol and what does it do?
beta 1 and 2 agonist- increase CO, relaxes smooth muscle, vasodilation of peripheral vasculature
What is a typical maintenance dose of isoproterenol?
0.5-5 mcg/min
What does isoproterenol do to myocardial O2 demand?
increases
What is the MoA of local anesthetics?
voltage-gated Na channel antagonist
What are the esters?
procaine, tetracaine (only 1 i in the name)
What are the amides?
lidocaine, bupivacaine, ropivacaine (>2 i’s in the name)
How are esters metabolized?
plasma esterases
How are amides metabolized?
liver
What does alpha 1 stimulation do?
increase vascular smooth muscle contraction, mydriasis, increase intestinal and bladder sphincter muscle contraction
What does alpha 2 stimulation do?
decreases sympathetic tone, decreased insulin release, decreased lipolysis, increased platelet aggregation
What does beta 1 stimulation do?
increases HR, contractility, renin release, and lypolysis
What does beta 2 stimulation do?
vasodilation, bronchodilation, increased lipolysis, insulin release, decreased uterine tone, relaxes ciliary muscle
What does beta 3 stimulation do?
increased lipolysis and thermogenesis
What does dopamine (DA)-1 stimulation do?
vasodilation of renal, cerebral, coronary, and splanchnic arteries
What are typical sizes of ETT for men vs women?
8 mm for men, 7.5 for women
What is the minimum ETT size needed for bronchoscopy?
7.5
What are some criteria for extubation?
stable vital signs, spontaneous RR 6-30, TOF 4/4, spontaneous TV >5 ml/kg and VC >15 ml/kg, protective reflexes returned, awake and able to follow commands
What is minute ventilation?
TV x RR
Describe controlled mandatory ventilation (CMV) mode
MV is set, breaths are not synchronized to patient’s effort
Describe assist control (AC)
minimum MV set, pt can initiate breaths and a set TV is delivered
Describe intermittent mandatory ventilation (IMV)
minimum MV set, pt can initiate extra breaths but no volume is delivered with them
Describe SIMV
variation of IMV where ventilator delivered breaths are synchronized with pt breaths
Describe pressure support ventilation (PSV)
pt determines TV and RR but a set pressure is delivered- it augments spontaneous breathing and is good for weaning
Describe how to dilute ephedrine in a syringe (at Grant)
initial concentration is 50 mg/1 ml- draw it up in a syringe with 9 mL of normal saline for a final concentration of 5 mg/ml
Describe how to dilute epinephrine in a bag (at Grant)
initial concentraiton is 1 mg/1 ml- draw up in a syringe and inject into a 100 ml bag of NS for a final concentration of 10 mcg/ml
Describe how to dilute nicardipine in a bag (at Grant)
Initial concentration is 25 mg/10 mL vial- remove 10 ml of NS from a 100 mL bag of NS, then draw up the 10 mL of nicardipine in an empty 10 mL syringe and inject into the remaining 90 ml of NS for a final concentration of 250 mcg/mL
Describe how to dilute norepinephrine in a syringe (at Grant)
initial concentraiton is 4 mg/250 ml premixed bag- draw up 5 mL of norepinephrine from bag in a 10 ml syringe and dilute with 5 ml of NS for a final concentration of 8 mcg/ml
Describe how to dilute phenylephrine in a bag (at Grant)- NOT the same as the prefilled syringes
initial concentration is 10 mg/1 ml vial- draw up 1 ml and inject into 100 ml bag for a final concentration of 100 mcg/ml
Describe how to dilute vasopressin in a syringe (at Grant)
initial concentration is 20 units/mL- draw 1 ml of vasopressin in 20 ml syringe and dilute with 19 ml of normal saline for a final concentration of 1 unit/ml
