Lecture 12- Anesthetic Medications Flashcards
What are the key things that make an ideal anesthetic? (7 things)
- rapid and pleasant induction and withdrawl
- skeletal muscle relaxation
- analegisa –> inability to feel pain
- high potency
- wide therapeutic index
- nonflammable
- chemical inertness
What does it mean if a drug has a “high therapeutic index”?
means the drug is…
a. SAFER
b. LESS TOXIC
What are the 4 stages of Anesthesia?
- Analgesia
- Excitement
- Surgical Anesthesia
- Medullary Paralysis
What is the first stage of Anesthesia
ANALGESIA
- pain is removed but still conscious
What is the second stage of Anesthesia
EXCITEMENT
- unconscious but possible unpleasant shaking, violence, fear
What is the third stage of Anesthesia
SURGICAL ANESTHESIA
- progressive muscle relaxation and unconsciousness
- risk of respiratory depression
What is the fourth stage of Anesthesia
Medullary Paralysis
- respiratory failure
- circulatory collapses
What are the 8 preoperative medications as adjuncts to surgery NAME and TRADE NAME?
- Diazepam –> valium
- Meperidine –> Demerol
- Sodium citrate/citric acid –> Bicitra
- Cimetidine –> Tagamet
- Famotidine –> Pepcid
- Lansoprazole –> Prevacid
- Metoclopramide –> Reglan
- Atropine
What are preop medications used for?
- reduce anxiety
- sedate
- produce amnesia
- increase comfort
- reduce gastric acidity
- increase gastric emptying
- decrease nausea and vomiting
- reduce incidence of aspiration
What is General anesthesia?
- whole body affected
- become unconscious by depressing CNS
- all muscles relaxed, reflexes dissappear reduces pain
- used in combination for smoothly and slowly induce anesthesia and allow prompt recovery, ensure wide safety margin, reduce side effects
What are the 2 types of General Anesthesia?
- Inhalation (Volatile liquids)
- Intravenous
What are the 3 phases of General Anesthesia?
- Induction
- Maintenance
- Emergence
What is the “induction phase” of general anesthesia?
- uses IV or inhalation techniques
- uses:
a. sedative-hypnotics
b. adjuvant IV agents (pain killers)
c. Neuromuscular blocking agent (blocks muscle mvmnt during surgery)
What is the “maintenance phase” of general anesthesia?
- making sure to maintain anesthetic state
- combo of IV and inhalation or total IV
- uses:
a. Neuromuscular blocking agent (muscle relaxation)
b. hemodynamic monitoring and support
What is the “emergence phase” of general anesthesia?
- return of consciousness and movement at the end of surgical procedure
- discontinue anesthetic and adjuvant agents
- reversal of Neuromuscular blocking agent
What is the most important and common mechanism of action of general anesthesia?
- GABA-A agonists
steps:
1. enhance GABA effect on GABA-A
2. hyperpolarize resting potential
3. supress neuronal excitability
4. produce CNS inhibition
In simple terms, what is the mechanism of action for general anesthesia?
Stimulate inhibitory / Inhibit stimulatory
What are other mechanisms for general anesthesia?
-NDMA anatagonists –> inhibit NMDA receptors to prevent neurotransmission of pain
What are 3 IV anesthetics?
- propofol
- ketamine
- fentanyl
What is propofol?
- IV anesthetic
- GABA agonist
- most common
What is Ketamine?
- IV anesthetic
- NMDA receptor anatagonist
What is fentanyl?
-IV anesthetic
- opioid agonist
- analgesic and sedative
What are 3 inhalation anesthetics?
- desflurane
- nitrous oxide (laughing gas)
- Sevoflurane
What are inhalation anesthetics?
- volatile liquids or gases
- delivered via specialized airway circuits
- has “minimal alveolar concentration”
