Flashcards in Pharmacologic Response to CPB- Exam 3 Deck (124)
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1
Pharmacokinetics
What the body does to the drug
2
Pharmacodynamics
How a drug interacts with the body to produce its effects
3
First order kinetics
elimination of a drug occurs at a constant fraction of drug remaining in the body per unit of time
4
Zero order kinetics
when drug administration exceeds the body's ability to clear it, leading to drug accumulation
5
To prevent drug accumulation, what should be done?
Drug infusion rates should be adjusted according to patient response
6
To prevent drug accumulation, what should be done?
Drug infusion rates should be adjusted according to patient response
7
Changes in Pharmacokinetics due to CPB
Hemodilution
Hypothermia
Perfusion
Acid-Base Status
Sequestration
8
Changes in Pharmacokinetics due to CPB
Hemodilution
Hypothermia
Perfusion
Acid-Base Status
Sequestration
9
Hemodilution
Reduction in circulating protein concentration
Reduction in RBC concentration
Reduction in concentration of free drug (unless your pump prime matches exactly)
Alterations in organ blood flow, affecting distribution and clearance
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Hemodilution
Reduction in circulating protein concentration
Reduction in RBC concentration
Reduction in concentration of free drug (unless your pump prime matches exactly)
Alterations in organ blood flow, affecting distribution and clearance
11
What happens if you add drugs to your prime BEFORE RAP? or AFter RAP?
Lose some when you rap
most of the time you wont have time to add drugs after you rap
usually you'll go on pump right after you rap
12
What happens if you add drugs to your prime BEFORE RAP? or AFter RAP?
Lose some when you rap
most of the time you wont have time to add drugs after you rap
usually you'll go on pump right after you rap
13
Hypothermia
Fluid shifts from intravascular to interstitial space
(altered volume of distribution, increased 3rd spacing)
Vasoconstriction (changes in organ perfusion)
Reduction in enzyme-mediated biotransformation
increased solubility of volatile anesthetics
14
Hypothermia
Fluid shifts from intravascular to interstitial space
(altered volume of distribution, increased 3rd spacing)
Vasoconstriction (changes in organ perfusion)
Reduction in enzyme-mediated biotransformation
increased solubility of volatile anesthetics
15
What are two important things to keep in mind regarding patient during perfusion?
Lungs excluded form circulation (valium, propofol, opioids)
Altered hepatic blood flow - vasoconstriction (fentanyl, propofol)
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What are two important things to keep in mind regarding patient during perfusion?
Lungs excluded form circulation (valium, propofol, opioids)
Altered hepatic blood flow - vasoconstriction (fentanyl, propofol)
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Acid Base Status
Altered organ blood flow (ph stat= increase cerebral blood flow)
altered ionization and protein binding
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Sequestration
Drugs may be taken up by various components of the CPB circuit
-coated tubing
-oxygenators
-hemofilters (many factors influence the movmement of drug across the membrane; degree of protein binding is a major determinant)
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When administering medications
Ensure you have physician's order or standing protocol authorizing you to administer the medication
The patient is not allergic to the medication
you should have the correct medication, the correct concentration and the correct dosage
Inspect the medication for expiration date, precipitates and sterility
20
When administering medications
Ensure you have physician's order or standing protocol authorizing you to administer the medication
The patient is not allergic to the medication
you should have the correct medication, the correct concentration and the correct dosage
Inspect the medication for expiration date, precipitates and sterility
21
What is in your drug box?
Heparin
Neo-Synephrine
NaHCO3
Lidocaine
MgSO4
Calcium
Potassium
Mannitol
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What is heparin sodium derived from?
Bovine lung tissue or porcine mucosa standardized for anticoagulant activity
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How is the potency of heparin sodium determined?
By biological assay using a USP reference standard based on units of heparin activity per milligram
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Units/Mg Heparin Conversation
100 units = 1 mg
Ex. 5,000 units = 50 mg
25
What is the action of heparin sodium?
Stops coagulation by potentiating antithrombin III and inhibiting the action of activated Factors IX and XI
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What is the action of heparin sodium?
Stops coagulation by potentiating antithrombin III and inhibiting the action of activated Factors IX and XI
27
How is heparin eliminated?
kidneys
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What is the half-life of heparin?
At CPB doses is 2 or more hours; prolonged by hypothermia and renal blood flow alterations
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What is the half-life of heparin?
At CPB doses is 2 or more hours; prolonged by hypothermia and renal blood flow alterations
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