Anesthesiology Flashcards
What is the mechanism of most IV and inhaled anesthetics?
Most facilitate inhibitory GABAergic neurotransmission by keeping Cl- channels open, and augment inhibitory glycinergic function.
Which two anesthetics have a different mechanism, and what is that mechanism?
Ketamine and Nitrous Oxide. These act by inhibiting excitatory glutamatergic channels (they block NMDA receptors, Nitrous Oxide also blocks kainate receptors)
Name the inhaled anesthetics.
SHINE DM
Sevoflurane, Halothane, Isoflurane, Nitrous Oxide, Enflurane, Desflurane, Methoxyflurane
What is the most commonly used inhaled anesthetic in the U.S.?
Isoflurane
Which inhaled anesthetics have low solubility (fast induction)?
Nitrous Oxide, Isoflurane, Sevoflurane, and Desflurane
*SIND- send them to sleep fast
Which inhaled anesthetics have a high solubility (slow induction)?
Enflurane, Methoxyflurane, Halothane
*MEH- meh, they’ll fall asleep eventually
Which inhaled anesthetics are almost never used?
Halothane and Methoxyflurane
What are the side effects associated with Nitrous Oxide?
Hypoxia upon discontinuation, can cause expansion of closed air spaces since it exchanges with N2
*don’t use w/ obstructed middle ear, air embolus, bowel obstruction, intraocular air bubble, or intracranial air
What are the side effects associated with Enflurane?
CV depression 2/2 decreased contractility, seizures, and uterine muscle relaxation.
Explain the relationship between anesthetics and GABA.
When GABA channels are kept open by the binding of anesthetics, it results in a much smaller voltage change when Na+ enters the neuron thus making excitation and depolarization more difficult and serving kind of like a buffer.
What side effects are associated with Isoflurane?
Progressive respiratory depression
What side effects are associated with Sevoflurane?
Reports of toxicity
What side effects are associated with Desflurane?
Irritating to the airways (cough-provoking, salivation, bronchospasm), evokes tachycardia, low volatility
What side effects are associated with Methoxyflurane?
Extensive metabolism and can produce renal failure and nephrotoxicity
What side effects are associated with Halothane?
Respiratory depression, hypotension 2/2 myocardial depression, bradycardia, transient arrhythmias, hepatitis (immune response)
Name the IV anesthetics.
Barbiturates (Sodium Thiopental), Propofol, Etomidate, and Ketamine
Which IV anesthetic does not cause respiratory depression?
Ketamine
Which IV anesthetic also provides analgesia?
Ketamine
Which IV anesthetic causes hallucinations, increased muscle tone, and incidence of involuntary movement?
Ketamine
*these effects are less common in children
What is pancuronium?
A muscle relaxant used to facilitate intubation.
Which pre-anesthetic medications induce amnesia?
Benzodiazepines (Midazolam, Diazepam) and Antimuscarinics (Scopolamine, Atropine)
Name the antiemetic often used to prevent aspiration.
Ondansetron (aka Zofran)
What can be given with anesthetics to provide analgesia?
Opioids (Fentanyl, Morphine)
What is used to prevent allergic reactions and provide some sedation?
Antihistamines (Diphenhydramine)
