General Anesthesia Flashcards
What is anesthesia?
A combination of amnesia, analgesia and muscle relaxation to allow the performance of surgery or other procedures.
3 phases of general anesthesia
- Induction
- Maintenance
- Emergence
- Induction is what?
2. Most commonly used agent?
- “Putting to sleep”
2. Most commonly used induction agent is Propofol
Propofol causes what? 3
- Drop in BP and
- cardiac output,
- antiemetic properties
Other agents for Induction? 2
- Etomidate
2. Ketamine
Why isnt etomide used very often as an induction agent?
Doesn’t cause vasodilation, higher rate of post op nausea, inhibits the biosynthesis of cortisol, use is limited due to increased risk of death by 2.5X
Ketamine: Used in which pts?
5
- hemodynamic instability,
- cardiac stimulant,
- significant analgesia,
- bronchodilation,
- hallucinations
Maintenance
Use what? 2
inhaled (volatile) or IV anesthetics
Maintenance
1. Inhalation anesthetic agents 2 kinds?
- IV anesthetic agents
2
- Inhalation anesthetic agents
Volatile anesthetic agents:
-Sevoflurane and desflurane
-Nitrous oxide: can be used in combo with volatile gases - IV anesthetic agents
- Propofol and
- remifentanil
- Emergence is what?
2. Can result in what?
- Waking up
2. Can result in autonomic hyper-responsiveness
Emergence:
1. Can result in autonomic hyper-responsiveness. This causes? 4
- What can blunt this response? 3
- Tachycardia,
- hypertension,
- bronchospasm,
- laryngospasm
- Short acting narcotics,
- beta blockers or
- lidocaine can blunt this autonomic response
Propofol (Diprivan)
- What kind of agent?
- Metabolized where?
- Excreted where?
- So it can be used for what?
- What kinds of surgery is it used for?
- ONset of action? Clearance?
Reversibility? - Onset?
- Duration?
- Non-barbiturate hypnotic agent
- Rapidly metabolized in the liver and
- excreted in the urine,
- so it can be used for long durations of anesthesia
- Used for
- general surgery,
- cardiac surgery,
- neurosurgery, and
- pediatric surgery - Rapid onset of action (distribution two to four minutes),
- rapid clearance, and
- reversibility of effect once the drip is shut off
- Onset 40 sec
- Duration 1-3 hours
Propofol (Diprivan)
1. Advantages? 2
- Disadvanatges? 2
- Some anti-emetic effect so less nausea and vomiting associated with use
- Clear-headedness during recovery
Milky looking solution (emulsion)
- Weaker amnestic effect than Midazolam (Versed)
- No analgesic effect
Propofol (Diprivan) Adverse affects? 4
- Can support rapid growth of microorganisms
- Hypotensive (administer slowly)
- May cause hypertonia and movement
- Respiratory depression
Ketamine (Ketalar)
1. MOA?
- Frequently used in who?
- Can also be used in who? 2
- Onset?
- Duration?
- Affects the senses, and produces a dissociative anesthesia (catatonia, amnesia, analgesia) in which the patient may appear awake and reactive, but cannot respond to sensory stimuli
- Frequently used in pediatric patients because anesthesia and analgesia can be achieved with an intramuscular injection
- Also used in
- high-risk geriatric patients
- and in shock cases, because it also provides cardiac stimulation - Rapid onset (30 sec)
- Short duration (5-10 minutes)
ANESTHESTIC GASES
are? 4
- Isoflurane (Forane)
- Desfluorane (Suprane)
- Sevofluorane (Ultane)
- Nitrous oxide
Anesthetic Gases
1. An important property of anesthetics is what?
- Once the anesthetic gas is turned off, the blood stream brings the gas where and it is eliminated here?
- The more soluble the gas is in blood, the _____ it takes to eliminate
- Which are the shortest-acting anesthetic gases because they are the least soluble in blood ? 2
- reversibility
- back to the lungs
- longer
- Nitrous oxide and desflurane
How do inhaled anesthetics work?
1. Inhaled anesthetics act in different ways at the level of the what?
- Disrupt normal synaptic transmission by what? 3
- CNS
2.
-interfering with the release of neurotransmitters from presynaptic nerve terminal (enhance or depress excitatory or inhibitory transmission)
- Alter the re-uptake of neurotransmitters
- Change the binding of neurotransmitters to the post-synaptic receptor sites