anesthetics Flashcards
susceptibility of nerve fiber types to local anesthetics
smaller, myelinated, high firing frequency fibers are blocked first Type B( preganglionic autonomics) and C (pain) fibers have high sensitivity
Benzocaine
topical agent only
anesthetic lubricant
Bupivacaine
long duration and prolonged anesthesia
more sensory than motor block
cocaine
topical anesthetic of upper respiratory tract
blockade of nerve impulses and local vasoconstriction actions
dibucaine
topical cream only due to toxicity with injections
lidocaine
amide local anesthetic
faster, more intense, longer lasting and extensive anesthesia
used as anti arrhythmic agent
Procaine
lower potency, onset and duration of action
used only for infiltration anesthesia
met to para-aminobenzoic acid which inhibits action of sulfonamide abx
MAC
minimal alveolar conc
ED50
Potency
1/MAC
lower the MAC the greater the potency
Toxicity of inhaled anesthetics
nausea
Halothane causes hepatitis
agents met to fluoride ions cause renal toxicity (enflurane and sevoflurane)
in combo with succinylcholine, causes malignant hyperthermia
etomidate
rapid onset and recovery
less rapid recovery compared to propofol
decreases cerebral blood flow
CV stability
decreased steroidogenesis and muscle movements
not analgesic
causes adrenal cortical suppression by inhibitor of 11B hydroxyls
ketamine
moderately rapid onset and recovery catatonia, amnesia and analgesic w/without loss of consciousness CV stimulation increased cerebral blood flow emergence reactions
methohexital
rapid onset and recovery
for short ambulatory procedures
barbiturate
midazolam
slow onset and recovery
used in balanced anesthesia and conscious sedation
CV stability and amnesia
Propofol
rapid onset and recovery induction and maintenance not analgesic causes hypotension due to vasodilation useful antiemetic action possible allergy low hangover effect decreased cerebral blood flow respiratory depressant
thiopental
rapid onset and recovery bolus does have slow recovery following infusion standard induction agent CV depression avoid in porphyrias
fentanyl
slow onset and recovery naloxone reversal marked analgesia conscious sedation opioid used in balanced anesthesia
fospropofol
water soluble pro-drug of propofol
onset and recovery are prolonged
less pain on administration
parasthesias and pruitius in inguinal region common side effect
dexmedetomidine
alpha2 agonist that produces hypnosis and analgesic
physiologic sleep state through activation of endogenous sleep pathways
moderate decrease in HR and SVR
used for short term intubation of ICU pts
Opioid analgesics
used in combo with benzos fentanyl sufentanil remifentanil morphine
Barbiturates
Thiopental methohexital quick plasma:brain equilibrium respiratory depression induce cyp450
benzodiazepines
diazepam
lorazepam
midazolam (water soluble)
used in perioperative period due to anxiolytic
flumazenil
benzodiazepine antagonist
NO
incomplete anesthetic
rapid onset and recover
