ANESTHETIC Flashcards
a reversible state of central nervous system (CNS) depression, causing loss of response to and perception of stimuli
General anesthesia
Milk of amnesia
Propofol
Often considered anesthetic adjunct
BZDsandBarbiturates
Block excitatory postsynaptic nicotinic Receptors
Inhalational
Notable for Cardio vascular toxicity
Halothane
Causes suppression of CV
Cardiovascularsystem
depress respiration but also act as bronchodilators
Respiratory system
Inhibition of the N-methyl-d-aspartate (NMDA) receptors
N2O,ketamine
consideration in px with neurologic disorders
epilepsy, MG, NM dse
The use if anesthetic can cause abnormality in pregnancy which resukts to:
fetal organogenesis
aplastic anemia
oral cleft, altered thermoregulation
Pre-anesthetics(Adjuncts) reduce gastric acidity
H2 blockers
Drugs that are administering prior to administrating the main anesthetic agent
Pre-anesthetics(Adjuncts)
Pre-anesthetics(Adjuncts) prevent allergic reactions;
Antihistamines
Most common anti cholinergic
Glycopyrrolate
prevent bradycardia and secretion of
fluids into the respiratory tract
Anticholinergics
Most potent synthetic opiod derivative
Fentanyl
allay anxiety and facilitate amnesia
Benzodiazepines
Causes tolerance to opiods
opioid addiction
produce negative effects
Concomitant Drug Use
time of administration untul the anesthetic effect manifest or begins in the body
Induction
discontinuation→consciousness/reflexes
Recovery
sustainedanesthesia
Maintenance
Respiration is rapid, and heart rate and blood pressure increase
Excitement (delirium/disinhibition)
Decreased awareness of pain
Analgesia
Phases of anesthesia
Induction
Maintenance
Recovery
STAGES OF ANESTHESIA
Analgesia
Excitement
Surgical anesthesia
Medullary (respiratory) depression
Ideal stage for surgery
Surgical anesthesia
Severe depression of the respiratory center
Medullary (respiratory) depression
Careful monitoring is needed to prevent undesired
progression to stage IV
Surgical anesthesia
↓required anesthetic doses
Concomitant Drug Use
Ventilation and or circulation must be supported to prevent death
Medullary (respiratory) depression
Induce anesthesia
IV agent
Maintaine anesthesia during surgery
Inhalational anesthetic
narrow therapeutic indices
Inhalational anesthetic
Smallest dose to take effect
Minimum Alveolar Concentration
median effective dose (ED50) of the anesthetic, expressed as the percentage of gas in a mixture required to achieve that effect
Minimum Alveolar Concentration
Also known as inspired gas in Inhalational anesthetic
Gas mixture
More potent
Small MAC
Larger MAC
less potent
Windows to the brain
alveoli
replacement of normal lung gases with the inspired anesthetic mixture
ALVEOLAR WASH-IN
conc in blood phase: conc in gas phase (in
equilibrium)
blood/gas partition coefficient
faster induction and recovery (N2O)
↓blood/gas coefficient
slower induction and recovery (Halothane)
↑blood/gas coefficient
Need to increase dose and the least potent
halothane
Most potent
desflurane
removal of anesthetic to peripheral tissues, which are not the site of action
Cardiac output
poorly perfused
Skeletal muscles, Fat, Bone,ligaments,and cartilage
relatively low capacity to store anesthetic
Bone,ligaments,and cartilage
large volume, prolongs the time required to achieve steadystate
Skeletal muscles
rapidly attain a steady state
BRAIN,HEART,LIVER,KIDNEY,ANDENDOCRINEGLANDS
discontinuation of anesthetic
WASHOUT
sepsis, acute intoxication, clonidine, dexmedetomidine
DECREASE MAC
nonflammable, nonexplosive agents, including nitrous oxide and volatile, halogenated hydrocarbons
Inhalational anesthetic
↓cerebrovascular resistance, ↑brain perfusion
Inhalational anesthetic
↑CNS catecholamines
INCREASE MAC
distribution and clearance of drugs
Liver
target organs for toxic effects
kidney
Increase the sensitivity of the γ-aminobutyric acid (GABAA) receptors to the inhibitory neurotransmitter GABA
Etomidate,Propofol, BZDs and Barbiturates
Considered as one of the most commonly used anesthetic most especially in the US
Propofol
No specific receptor has been identified as the focus of general anesthetic action.
MOA of General anesthesia
Most used drugs to facilitate amnesia
Diazepam and midasolam
