SAS #3: General anesthetics

analgesia

a state of decreased awareness of pain and sometimes with amnesia

general anesthesia

characterized state of unconsciousness, analgesia, amnesia, skeletal muscle relaxation and loss of reflexes

anxiolytics/sedatives

drugs that promote relaxation and lower anxiety

hypnotics

drugs used to induce sleep

general anesthetics

anesthetics that are administered intravenously or by inhalation

local anesthetics

anesthetics that are given either intramuscular, intradermal, or topical

induction

- the time of administration of an anesthetic to develop effects

- how fast the anesthetic reaches the brain

propofol

it is a general anesthetic that is IV-administered and produces unconsciousness in 30-40 seconds

sevoflurane

it is used as an alternative if there is no IV access for propofol, and is inhaled instead

maintenance

it provides sustained anesthesia

recovery

the time from discontinuation of the anesthetic until consciousness returns

GABAa receptor

the target site of action for general anesthetics

N-methyl-D-aspartate (NMDA) receptor

the target site of action for ketamine

barbiturates

S-H drugs that rapidly cause anesthesia when IV administered

balanced anesthesia

use of a combination of IV and inhaled drugs

volatile anesthetics

inhaled anesthetics that are liquid at room temperature

gaseous anesthetics

inhaled anesthetics that are gasses at room temperature

halothane, enflurane, sevoflurane, desflurane, isoflurane

common volatile anesthetics

nitrous oxide, xenon

common gaseous anesthetics

minimum alveolar concentration

the anesthetic concentration that eliminates pain stimuli in 50% of the population

stage 1 analgesia

stage 2 excitemebt

stage 3 surgical anesthesia

stage 4 medullary depression

what are the 4 stages of the depth of anesthesia

stage 1 analgesia

it is the stage where the patient has decreased pain awareness but may or may not be amnesic

Stage 2 (Excitement, Delirium)

it is the stage where the patient is excited and delirious, has decreased pain stimuli, exhibits irregular respiration, and is amnesic

stage 3 surgical anesthesia

it is the stage where the patient is unconscious, and shows regular respiration with complete numbness

stage 4 medullary depression

The patient develops severe respiratory and cardiovascular depression that requires mechanical and pharmacologic support.

decreased cerebral blood flow

- lesser blood flow to the brain

what are the CNS effects of inhaled anesthetics

volatile anesthetics and nitrous oxide

which anesthetics causes increased cerebral blood flow

decreased arterial blood flow

what are the cardiovascular effects of inhaled anesthetics

act as bronchodilators (lung relaxation)

what are the respiratory effects of inhaled anesthetics

desflurane

what inhaled anesthetic causes bronchospasms

enflurane

what inhaled anesthetic causes breath-holding

Decreased glomerular filtration rate and urine flow

what are the renal effects of inhaled anesthetics

nitrous oxide

which anesthetic has little to no effects on uterine muscle contraction

halogenated anesthetics

anesthetics that are potent uterine muscle relaxants

Nephrotoxicity

rapid deterioration of the kidney functions

enflurane

what inhaled anesthetic is nephrotoxic

sevoflurane

safer alternative to enflurane that can prevent nephrotoxicity

nitrous oxide

which inhaled anesthetic causes megaloblastic anemia under prolonged exposure

nephrotoxicity

hematotoxicity

hepatotoxicity

malignant hyperthermia

what are the toxicities related to inhaled anesthetic use

succinylcholine

what inhaled anesthetic causes malignant hyperthermia

dantrolene

used as treatment for succinylcholine/malignant hyperthermia

halothane

exposure to what inhaled anesthetic causes hepatotoxicity (liver toxicity)

Fospropofol

the highly water soluble prodrug form of propofol

thiopental and methohexital

barbiturates that cause rapid stage 3 surgical anesthesia

midazolam

it is a benzodiazepene most commonly used with inhaled anesthetics and IV opioid

diazepam and lorazepam

alternatives to midazolam

ketamine

a dissociative anesthetic drug, similar to PCP, that acts as an NMDA receptor antagonist

opioids

drugs that cause more rapid analgesia than morphine

etomidates

it is a hypnotic to induce anesthesia but lacks analgesic activity, and is usually only used for patients with coronary artery disease

dexmedetomidine

drugs used for short term sedation in an ICU setting

vecuronium

nocuronium

succinylcholine

examples of neuromuscular blockers

fentanyl

most commonly used opioid

phencyclidine (PCP)

ketamine is a congener of what psychotomimetic agent?

volatile anesthetics

which inhaled anesthetics commonly provide maintenance?

dissociative anestheisa

a state where the patient is unconscious but appears to be awake and does not feel pain

flumazenil

it is an antagonist used to accelerate recovery from midazolam and other benzodiazepines

naloxone

opioid antagonist

cortisol and aldosterone

the adverse effects of etomidates include the decreased levels of what enzymes?

dexmedetomidines

when used in general anesthesia, this drug decreases the dosage requirements for other anesthetics