Definitions (Ex1) Flashcards
Anesthesia definition
Lack of feeling or sensation
General anesthesia definition
Drug- Induced loss of consciousness
Regional anesthesia definition
Interrupted sensory nerve conduction resulting in loss of sensation
Spinal anesthesia location
Intrathecal space
Epidural anesthesia location
Outside of the dura
Minimal sedation characteristics
Responds to verbal
Unaffected airway/ventilation/CV
Moderate sedation characteristics
Responds to verbal or touch
Usually adequate airway/ventilation/CV
Deep sedation characteristics
Responsive to painful stimulation
May need assistance with airway/ventilation
CV usually maintained
Triad of anesthesia
Amnesia
Analgesia
Muscle relaxation
Balanced anesthesia adds ____ to the anesthesia triad
Homestasis
Phases of anesthesia administration (5)
Preoperative
Induction
Maintenance
Emergence
Postoperative
Stage 1 of anesthesia
Begin induction to loss of consciousness
Stage 1 plane1 of anesthesia
No amnesia or analgesia
Stage 1 plane 2 of anesthesia
Amnesia and partial analgesia
Stage 1 plane 3 of anesthesia
Complete analgesia and amnesia
Stage 2 of anesthesia
-Loss of consciousness to onset of auto breathing
-can be bothered/unsettled
-move through quickly
Stage 2 anesthesia symptoms (5)
-Delirium
-Undesired CV excitation
-Laryngospasm
-Emesis
-Dysconjugate eye movement
Stage 3 of anesthesia
-Onset of auto breathing to respiratory paralysis
Stage 3 plane 1 of anesthesia
Cessation of eyeball movement
Stage 3 plane 2 of anesthesia
-Beginning of intercostal muscle paralysis
-Increased tear secretion
Stage 3 plane 3 of anesthesia
-Desired for surgical start
-pupils dilate
-desired prior to muscle relaxants
Stage 3 plane 4 of anesthesia
Diaphragmatic paralysis (apnea)
Stage 4 of anesthesia
Stoppage of respiration till death
Tachyphylaxis definition
Tolerance
Common anesthesic solubility
Lipid soluble
Pharmacokinetics definition
What the body does to the drug (ADME)
Vessel rich groups
High cardiac output organs:
-heart
-lungs
-liver
-kidney
-brain
Vessel rich group CO%
75%
Muscle CO %
19%
Fat CO %
6%
Vessel poor CO %
0%
Protein binding affect on Vd
Higher protein binding => less free drug
-low albumin/protein => more free drug than intended => more effect
Common causes of decreased plasma proteins (5)
Age
Hepatic disease
Renal failure
Pregnancy
Malnutrition
High volume of distribution
Poor protein binding and lipophilic
Small volume of distribution
Highly protein bound
Metabolism process
Conversion from lipid soluble to water soluble for excretion
Prodrug definition
Drug administered in inactive form and converted to active form
Most common metabolism pathway
Hepatic Microsomal enzymes
Most common hepatic Microsomal enzyme
CYP3A4: metabolizes more than 50% of drugs
Phase I reactions
Oxidation
Reduction
Hydrolysis
Phase II reaction
Conjugation
Conversion to water soluble compound for elimination
Cause of dark red liver color
Hepatic Microsomal enzymes containing heme cofactor (iron)
Enzyme induction
Increases enzyme effect
Enzyme inhibition
Decreases enzyme effect
Flow limited hepatic clearance definition
Flow to the liver limits the metabolic rate
Capacity limited hepatic clearance definition
Livers ability to metabolize limits metabolic rate
Elimination half-time definition
time to eliminate 50% of drug from PLASMA
Elimination half life definition
Time to eliminate 50% of drug from TISSUE
Context sensitive half-time definition
Time for 50% decrease of drug after INFUSION discontinued
-longer infusion given => longer to wear off
Acids are ionized in ____ pH
Alkaline
Bases are ionized in ____ pH
Acidic
Non-ionized vs ionized drug crossing
Non-ionized cross lipid barriers
Non-ionized solubility
Lipid soluble
Ionized solubility
Water soluble
Non-ionized pharmacologic effect
Active drug
ionized pharmacologic effect
Inactive drug
Ionization calculations pk/pH
Weak Acids: pk After pH
Weak Bases: pk Before pH
Ionization calculations negative numbers
Non-ionized
Ion trapping explanation
Ionized drugs can be “trapped” such as in a fetus
Ionization effects
Ionized drugs lose effectiveness
Pharmacodynamics definition
What the drug does to the body
Elderly effects on ADME
-Decreased CO => decreased blood flow to brain and liver
-decreased protein binding => more free drug
-increased body fat => more absorption of lipid soluble
Potency definition
Less drug needed to produce effect = higher potency
Efficacy definition
Drug produces higher effect = higher efficacy
Effective dose definition
ED50: dose to produce effect in 50% population
Lethal dose definition
LD50: dose to produce death in 50% population
Therapeutic index definition
Ratio between LD50 and ED50
-wider index = safer
Enantiomer definition
-Chemically identical
-mirror image
-may produce different effects
Racemic mixture
Mixture of different isomers likely producing different effects
Pharmacogenetics impact
Specific genes or genomes can influence responses to drugs and help predict effects