Ch 12 (test 2) Flashcards
Anesthetics
Drugs that depress the CNS and PNS to produce a loss of consciousness, loss of pain response or other stimulus, and muscle relaxation. They work by interfering with nerve conduction. Classified as general or local according to their action.
General anesthetics
drugs used to provide pain relief, analgesia, amnesia, and unconsciousness. They block muscle reflexes during surgery. (anesthesiologist or nurse anesthetist)
High risk for general anesthetic
- Those with CNS disease
- Respiratory disease
- cardiac disease
Helper drugs for anesthesia
- anticholinergic: decrease secretion
- sedative/hypnotic: relax, amnesia
- antiemetics: decrease N and V.
- antihistamine: lessen risk for allergy
- narcotics: aide analgesia/sedation
Nitrous oxide
inhalation general anesthesia vaporized in oxygen (12:2)
ethrane
inhalation general anesthesia vaporized in oxygen (12:2)
Ketalar
parenteral general anesthesia (12:1)
Diprivan, proprofol
parenteral general anesthesia (12:1)
pentothol
parenteral general anesthesia
Overton-Meyer theory
for all anesthetics, potency varies directly with lipid solubility. Across a continuum of drug potency, fat-soluble drugs are stronger anesthetics than water-soluble drugs. (lipid-soluble anesthetics can cross the blood-brain barrier to concentrate in nerve cell membranes).
General anestesia effect on organs
- resp: decrease muscles for resp: dec gas exchange, loss of cough and gag reflex: possible laryngospasms
- cardia; decrease BP, tachycardia
- GI: decreases blood flow to liver
- Renal: decrease GFR
- Cutaneous: vasodilation (cold)
- CNS: dec alertness, dec LOC
Inhaled anesthesia
- inhaled and excreted by lungs
- hypothermia in PACU
- with elderly can cause confusion
- halogen gas anesthetics can produce liver toxicity
- malignant hyperthermia
injectable anesthesia
- used for SHORT duration surgeries
- 15 seconds to effects
- SE: hangover, apnea, laryngospasm/coughing after extubation, dec BP, dec HR, restlessness, N&V.
exaggerated patient response to inhaled anesthesia
- hypotension
- prolonged respiratory depression
- prolonged recovery period
malignant hyperthermia
occurs in genetically susceptible patient; there is a failure of calcium uptake by muscle cells. Body temperature increase, tachycardia, tachypnea, and muscle rigidity.
Dantrium
- antidote to inhaled anesthesia in event of malignant hyperthermia.
- skeletal muscle relaxant that decreases metabolic activity.
Local anesthetics
A regional anesthetic that renders a specific area of the body insensitive to pain without a loss of consciousness. decreases pain by blocking the conduction of pain impulses in the circumscribed area.
Types of Local anesthetic
- epidurals: inject anesthetic via catheter into epidural space.
- Novocain: in gums for dental work
- spinal anesthesia; intrathecal;
- nere blocks; injected into nerve root
local anesthetic mechanism of action
interferes with pain transmission in the area. nerve conduction is blocked only where the anesthetic is applied. It blocks the generation and concentration of impulse through all nerve fibers by blocking the movement of ions (Na, K, and Ca).
Topical local anesthetics
- applied to skin
- root word ends in caine
- gels, lotions, ophthalmic drops.
Parenteral local anesthetics
injected directly into region and stays there.
Xylocaine
parenteral local anesthetic
Procaine
parenteral local anesthetic
Lidocaine
Parenteral local anesthetic that can be mixed with epinephrine (vasoconstrictor) to decrease blood loss and prevent systemic absorption of the drug.
