NCE part 1 Flashcards
which two volatile anesthetics decrease SVR the most
Isoflurane and Desflurane
Isoflurane causes hypothermia …why
because it suppresses the hypothalamic temperature regulators
which agents are volatile
Sevoflurane Desflurane Isoflurane Enflurance Halothane
how do volatile anesthetics affect cerebral vessels and cerebral blood flow.
Dilate cerebral vessels
Increase cerebral blood flow
Increase cerebral blood flow and ICP
Decreases neuronal function and cerebral metabolism
which three gases similarly depress cerebral metabolic rate
Iso, Des, Sevo
how do we negate the increase ICP with Isoflurance (remember its the least to dangerously increase ICP)
hyperventilate
Hypoxic Pulmonary Vasoconstriction is inhibited at what MAC
HPV is inhibited by a high concentration of volatile (1-1.5 or higher MAC)
What volatile is considered completely halogenated with fluorine?
Des is considered to be completely halogenated with fluorine
what volatile has fluorine substituting halogen
sevoflurance
which two volatile most depress ventilation
Des, Enflurane
which volatile depress ventilation the least
Halothane
what volatile agent Most depress the baroreceptor reflex
Halothane and Sevo: No increase in HR even with decreases in blood pressure
Baroreceptor: “DISH” least to greatest
- S/H no increase in HR w/low BP
- D/I increase in HR w/low BP
what volatile agent Least depress the baroreceptor reflex
Iso and Des: HR increases as a reflex to decrease in blood pressure
Baroreceptor: “DISH” least to greatest
- S/H no increase in HR w/low BP
- D/I increase in HR w/low BP
Acute ETOH intoxication effect on MAC
Decreases
Rank opioids most lipid soluble to least lipid soluble Meperidine Remifentanil Morphine Fentanyl Sufentanil alfentanil
Sufentanil »_space; fentanyl»_space;> alfentanil»_space;> meperidine > remifentanil > morphine
“Single Females And Males Run Marathons”
23311 (arrow pattern)
What receptors do spinal opioids work
Primarily Mu-2 but work on mu-1, kappa, and delta to produce supraspinal analgesia
Stimulation of mu-1 receptors what responses:
Spinal and supraspinal analagesia Euphoria Miosis Bradycardia Hypothermia Urinary retention pruritus
Mu-1 have a high or low abuse potential
?
Low abuse potential
Opioid can cause nausea and vomiting by
Stimulation of CTZ of the fourth ventricle (floor). The triggered CTZ activates vomiting center near the brain stem
Most opioids are metabolized by the liver. Which is not and what is it metabolized by?
Remifentanil and is metabolized by nonspecific esterases in the blood stream.
Agonist/antagonist opioids work on what receptor(s) for therapeutic effect
Primarily Kappa
Also on delta
Naloxone reverses what actions of opioids
Pruritus
Urinary retention
N/V
Higher doses of naloxone are required to reverse what opioid issue
Reverse profound sedation and respiratory depression
Does morphine produce arterial or venous dilation
Both due to histamine release
What two opioids cause histamine release
Morphine and Meperidine
There are 3 CV actions that may cause a decrease in BP in an anesthetized patient given a high dose of fentanyl
Decrease SVR (dilate arterial vessels Decrease venous return (dilate venous capacitance vessels Decrease in HR
how are esters hydrolyzed
Hydrolyzed by plasma and tissue cholinesterase
PABA is excreted where
urine
is there cross contamination between esters and amides
no
how could an ester be prolonged
plasma cholinesterase deficiency
what is responsible for esters reaction
PABA is responsible for the greater portion of allergic reactions to esters
Lipid solubility =
potency of LA
Protein binding =
duration of LA
pKa =
(50:50 ionized and unionized)
Which of the following are short acting local? Long acting local? Procaine Lidocaine Prilocaine Bupivacaine Tetracaine mepivacaine
Short: procaine
Long: bupivacaine and tetracaine
What is the progression of blockade:
Autonomic -Temperature -Pain Sensation -Touch -Pressure Motor -Vibration -Proprioception
Treatment of LA Toxicity?
20% Intralipid:
1.5 mL/kg over 1 minute
Continuous infusion of 0.25 mL/Kg until hemodynamically stable
Limit: 10 mL/Kg over 30 minutes
nitrous administered alone does not cause hypotension but instead causes
When administered alone Nitrous does not cause hypotension but instead causes cutaneous vasoconstriction and increased SVR
when administered alone what does nitrous cause
Nitrous will cause an increase in cardiac output when administered alone
Dose limit for exogenous Epi
5-6 mcg/kg with these volatiles
Tissue trauma: fluid replacement
Minimal?
Moderate?
Extensive?
Tissue trauma:
Minimal – 5 ml/kg/hour
Moderate - 6 ml/kg/hour
Extensive – 8 ml/kg/hour
Goal Directed Fluid Therapy is guided by UOP
Keep 0.5 ml/kg/hour
Hemodynamics
These three depress cerebral metabolic rate the most…
these two depress it less
iso, des, sevo
those three depress more than enflurane and halothane.
what gas is the least likely to dangerously increase ICP if the patient is kept moderately hypocapnic
Iso
volatile anesthetics do what to the ventilatory response to c02
Volatile anesthetics alter the ventilatory response to CO2 by decreasing that response when used in dose-dependent increments
how much MAC- will completely block the ventilatory response to hypoxemia
0.1 MAC
which gas has a slightly higher incidence of causing a cough reflex during maintenance when used with a LMA
isoflurance
will hypoxemia stimulate ventilation when using a volatile agent
no
