NCE Pharm review 1 and 2 power points Flashcards
The two volatile agents that decrease Systemic Vascular Resistance more than the others?
Iso
Des
Which VA causes hypothermia because it suppresses the hypothalamic temperature regulators?
Isoflurane
What four things do VA change in relation to blood flow and the brain?
Dilate cerebral vessels
Increase cerebral blood flow
Increase cerebral blood flow and ICP
Decreases neuronal function and cerebral metabolism
The increase in ICP by Iso can be negated by what?
hyperventilation
Which VA is the least likely to dangerously increase ICP if keep the patient moderately hypocapnic?
Iso
Which VA has a slightly higher incidence of causing a cough reflex during maintenance when used with a LMA?
Isoflurane
How much MAC of a VA will completely block the ventilatory response to hypoxemia. Therefore, hypoxemia will not stimulate ventilation when using a volatile agent?
0.1 MAC
Hypoxic Pulmonary Vasoconstriction HPV is inhibited by a high concentration of volatile, what is the concentration?
1-1.5 or higher MAC
What volatile is considered completely halogenated with fluorine?
Des
Volatile agents that suppress ventilation the most?
The least?
Most: Des, Enflurane
Least: Halothane
What volatile agents most depresses the baroreceptor reflex?
Which one does it the least?
Most depress : Halothane and Sevo: No increase in HR even with decreases in blood pressure
Least depress: Iso and Des: HR increases as a reflex to decrease in blood pressure
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
What receptors do spinal opioids work on?
Primarily Mu-2 but work on mu-1, kappa, and delta to produce supraspinal analgesia
Stimulation of mu-1 receptors cause what response?
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 forth ventricle (floor). The triggered CTZ activates vomiting center near the brain stem.
Which opioid is not metabolized by the liver?
Remifentanil and is metabolized by nonspecific esterases in the blood stream.
Agonist/antagonist opioids work on what receptor(s) for therapeutic effect?
Primarily Kappa and 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 ester locals “metabolized”?
Hydrolyzed by plasma and tissue cholinesterase
PABA is excreted where?
PABA is excreted unchanged in the urine
True or False?
Cross reactions between esters and amides?
No cross reactions
How could an ester be prolonged?
Prolonged in plasma cholinesterase deficiency
What does the PKa of a LA mean?
when 50% is ionized and 50% is unionized
lipid solubility of a LA parallels what?
potency of the LA
Protein binding of a LA parallels what?
duration of action of the LA
What is the short acting LA and what is the long acting LA?
Short : procaine
Long: bupivacaine and tetracaine
What is the progression of LA blockade? (what do you lose first to last)
Autonomic Temperature Pain Touch Pressure Motor Vibrate/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
When administered alone does Nitrous cause hypotension?
No, but instead causes cutaneous vasoconstriction and increased SVR.
When administered alone what will Nitrous cause?
Nitrous will cause an increase in cardiac output when administered alone.
(also cutaneous vasoconstriction and increased SVR)
What is the dose limit of exogenous EPI if using Iso, Des, or Sevo?
5-6 mcg/kg
Fluid replacement for surgical trauma?
Minimal – 5 ml/kg/hour
Moderate - 6 ml/kg/hour
Extensive – 8 ml/kg/hour
Goal directed fluid therapy is guided by UOP, what is the amount of UOP you want per hour?
0.5ml/kg/hour
hemodynamically stable
Nerve fibers, tell me about type A, B, and C in relation to myelination?
Type A = Heavy myelination
Type B = Light myelination
Type C = No myelination
Type A nerve fibers have alpha, beta, gamma, and delta fiber subtypes, what are the reactions associated with each subtype?
Alpha: Proprioception, motor
Beta: Touch, pressure
Gamma: Muscles spindles
Delta: Pain, temperature
Type B nerve fibers, are they pre or post ganglionic autonomic?
preganglionic autonomic
Type C nerve fibers details?
Dorsal Root: Pain
Sympathetic: Postganglionic
Which ester local anesthetic is the #1 cause of methemoglobinemia?
Benzocaine
explain zero order pharmacokinetics?
What drugs follow this order?
Constant amount of drug is eliminated per unit of time
Metabolic pathways are considered saturated
Drug Examples: salicylates, theophylline, phenytoin, and ethanol
First order pharmacokinetics explain what you know?
Constant fraction of drug is eliminate per unit of time
Elimination rate is proportionated to the amount of drug in the body
Most drugs are eliminated in this manner
What is volume of distribution?
Amount of the drug in body divided by the amount in the blood
Small volume of distribution would tell you what about a drug?
lipid insolubility
Large Vd would tell you what about a drug?
lipid solubility (soluble)
Clearance is defined as?
Complete drug removal from a volume of plasma per unit of time
elimination half time is defined as?
Time to eliminate 50% of drug from the PLASMA
4 half lives = 94% complete
define context sensitive half time?
Describes the time necessary for the plasma drug concentration to decreases by 50% (or any other percentage) after discontinuing a continuous infusion of a specific duration (context refers to infusion duration). It considers the combined effect of distribution and metabolism as well as duration of continuous IV administration on drug pharmacokinetics
The relationship between Volume of Distribution, Clearance, and Half-Life?
T1/2 = 0.693 x Vd/CL