Anesthetic Agents Flashcards
loss of pain w/ loss of consciousness
Anesthesia
(paralysis of skeletal muscles)
Akinesia
main side effects of Anesthesia
CNS depression
anesthesia’s that can result to loss of consciousness:
- Systemic-acting Anesthesia
- General Anesthesia
- Intrathecal Injection
- SUBARACHNOID OR SPINAL anesthesia
- EPIDURAL anesthesia
anesthesia that are strictly sedatives→ hypnosis-sleep
GENERAL anesthesia
– uses amide anesthetics (L3-L4)
- used in abdominal surgery
SUBARACHNOID OR SPINAL anesthesia
route of morphine (Narcotic analgesic)
EPIDURAL anesthesia
– periocular anesthesia (subconjunctiva, sub Tenon), retrobulbar (anterior, posterior)
ocular injections anesthesia
Topical Ocular anesthesia uses what group of anesthesia:
ESTER anesthesia (Proparacaine & Benoxinate)
ocular injections uses what group of anesthesia:
AMIDE anesthesia (Lidocaine)
- loss of pain w/o loss of consciousness, intact motor function (no akinesia)
Analgesia
most common Narcotic Opioids analgesic:
Morphine
4A’s effects of NSAIDs:
- Analgesic
- Antipyretic
- Anti-inflammatory
- Anti-platelets/thrombotic
relieves pain:
Analgesic
relieves fever
Antipyretic
it is a non-NSAID that has analgesic and antipyretics without anti-inflammatory effect
Paracetamol / Acetaminophen
most common used NSAIDs:
Aspirin
Mefenamic,
Naproxen,
Ibuprofen
2 Mechanism of Action of Anesthetic Agents:
A. Specific receptor theory
B. Membrane expansion theory
theory that Blocks nerve conduction by decreasing the permeability of nerve cell membrane to Na+ ions by blocking the openings of the Na+ channels thus interferes with the depolarization process.
Specific receptor theory
theory in which In uncharged or unionized form, the anesthetic agent is absorbed at the cell membrane and becomes part of cell membrane structure at the Na+ channel which altering the channel configuration.
Membrane expansion theory
Classifications of Anesthetic Agents based on:
Biochemical structure
Ester group
Amide group
anesthetic group– topical destroy by esterase (tears)
Ester group
anesthetic group - injection route
destroyed by the liver
Amide group
Ester group anesthetics examples:
- Procaine
- Tetracaine
- Benoxinate/Oxybuprocaine
- Proparacaine
- Benzocaine
- Cocaine
the only natural anesthesia, narcotic analgesic,
1st discovered
Cocaine
2nd discovered,
used for short procedure
Procaine
3rd discovered Ester group anesthetic
Tetracaine
most common Ester group Anesthetic:
Proparacaine
Amide group anesthetics examples:
- Lidocaine
- Etidocaine
- Mepivacaine
- Bupivacaine
- Prilocaine
most common Amide group anesthetic:
Lidocaine
Routes of administration of anesthetic agents:
I. Topical local ester anesthetic agents
II. Injectable local amide anesthetic
Indications of ocular Local Anesthetics:
- Force duction test
- ElectroRetinoGraphy (ERG)
- Goldman applanation tonometry
- Gonioscopy
- Corneal epithelial debridement or Corneal scraping
- Fundus-contact condensing lens examination
- Foreign Body & Suture removal
anesthesia used in Forced duction test:
cocaine or lidocaine
anesthesia used in ElectroRetinoGraphy (ERG):
tetracaine
anesthesia used in Goldman applanation tonometry:
proparacaine or benoxinate
anesthesia used in Gonioscopy:
proparacaine or benoxinate
anesthesia used in corneal epithelial debridement/corneal scraping:
cocaine or tetracaine
anesthesia used in fundus-contact condensing lens examination
proparacaine
anesthesia used in foreign body & suture removal
proparacaine
Ocular side effects of topical anesthetics:
- Mild stinging & burning sensation - most common
- Conjunctival Vasodilation - red eyes
- Shortening of TBUT
- decrease reflex tearing
- decrease blinking - DES
- decrease epithelial mitosis & migration (delay corneal healing)
- corneal edema - blurred vision
- Punctuate epithelial keratitis
- Epithelial desquamation
- Allergy - at lids & conjunctiva
Ocular side effects of topical anesthetics:
- Mild stinging & burning sensation - most common
- Conjunctival Vasodilation - red eyes
- Shortening of TBUT
- decrease reflex tearing
- decrease blinking - DES
- decrease epithelial mitosis & migration (delay corneal healing)
- corneal edema - blurred vision
- Punctuate epithelial keratitis
- Epithelial desquamation
- Allergy - at lids & conjunctiva
Systemic side effects of local injectable anesthetics:
CNS DEPRESSION - early excitatory effects
- restlessness
- anxiety
- dizziness or vertigo
- tinnitus (ringing at the ear)
- miosis
- tremors
- convulsive seizures - most serious
Systemic side effects of local injectable anesthetics:
CNS DEPRESSION - depressive effects
- drowsiness
- sedation
- unconsciousness
- coma
- respiratory failure (apnea)
Systemic side effects of local injectable anesthetics:
at Cardiovascular system
- hypertension
- bradycardia then tachycardia
- decrease cardiac output
- peripheral vasodilation
- A-V heart block
- circulatory collapse (shock) → cardiac arrest
- methemoglobinemia → hypoxia