Lecture 6 - Clinical Uses of anesthetics Flashcards
what are some desired components of General anesthesia?
• Desired components – amnesia, (Preemptive) analgesia, anxiolysis/sedation, suppressed stress and hormonal responses, immobility/muscle relaxation, autonomic areflexia
what are the phases of anesthesia –
(pre induction), induction, maintence, emergence
What are the three most commonly used IV anesthetics?
Propofol
Ketamine
Etomidate
Propofol –
Mechanism
Pros vs Cons
Mechanism – potentiation of GABA mediated inhibition
Pros – Rapid onset/short acting; anti-emetic, bronchodilation
Cons – pain on injection; no analgesia, hypotension
Ketamine
Mechanism
Pros vs Cons
Mechanism: NMDA receptor antagonists, and some opioid receptor function
Pros – dissociative states, bronchodilation, POTENT ANALGESIC,
COns – Hypertension, Increased ICP, use with caution CAD/CVA patients, tachycardia. PSYCHOTROPIC SIDE EFFECTS
Etomidate
Mechanism
Pros vs cons
potentiates GABA mediated inhibition
Pros – Cardiovascularly stable (no effect on the heart of CV). Great for CV unstable patients
Cons – adrenal suppression, pain on injection, myoclonus
Opiods – pros vs cons
Pros – Analgesia
§ Minimal cardiac depression; reduces inhalational agents; versatile (IV, IM, SL, regional anesthesia)
○ Cons – Respiratory depression
bradycardia, skeletal muscle rigidity, nausea and vomiting
Of the opioids which have the shortest time of onset?
Remifentanil > alfentanil < Fentayl< Morphine/Meperidine/< Methadone – minutes
How is immobility achieved during surgery?
what are the two classes
Depolarizing and Non Depolarizing Muscle relaxants
Depolarizing immobility agent
Mechanism
pros
cons
Succinylcholine –
Mechanism – nicotinic ACH R Agonist; persistent depoarlization of the end plate
Pros – fast onset, short duration
Cons – Hyperkalemia, Trigger of Malignant Hyperthermia, Increased ICP/IOP
will be prolonged in persons who have acetylcholinesterase mutations
Non Depolarizing immobility agents
Mechanism
Pros
cons
Rocuronium, Vecuronium, Pancuronium, Cisatracurium
Mechanism – competitive antagonists of the Nicotinic ACH R
Pros – fast Onset, Longer Duration
Immobility agents –
which has the fastest onset ?
duration shortest to longest ?
Fastest onset – Sux (1-1.5 minutes)
Duration
Sux < Roc < Vec = Cis < Pancuronium
Pre- induction – what medication clsas is commonly used for anti-anxiety/amnesia prior to general anesthesia?
Versed (midazolam) – and other benzos
what are the common inhalational induction agents?
which is the most commonly used? why?
Liquid: Isoflurane, Sevoflurane, Desflurane, (Halothane)
Gaseous form: Nitrous oxide
Isoflurane – most commonly used – cheap and long lasting
why must N2O be combined with other medications?
when is N2O contra-indicated ?
Combined with other meds bc its can’t reach MAC of 1 on its own
Contraindicated in surgeries with open air pockets such as laproscopic surgeries, bowel obstruction surgeries, pneumothroax, middle ear surgeries.
which inhaled agent is good for kids before proceeding with another inducing agent ? why?
§ Sevoflurane: not reactive for airways; best for kids
Then switch to Isoflurane after airway secured
patients with heart disease
- which Inhaled anesthetic is known to cause tachycardia?
- which IV inducing agent is known to cause tachy?
- –which IV inducing agent is best for cardiovascularly unstable patients
- –which opiate is best for patients with CV instability?
Inhaled tachy – desflurane
IV tachy – ketamine
CV unstable patients – Etomidate and Fentanyl
which immobility agent is best for persons with poor kidney function?
Cis astricurium
