Neuroanestesia

Question 1

Efeitos dos anestésicos no FSC

Answer 1

1. IV agents—IV induction agents generally decrease CBF. Ketamine is the only exception in that it increases CBF.
2. Opioids generally either have no effect or decrease CBF. Remifentanil increases CBF at low sedative doses.
3. Benzodiazepines reduce CBF.
4. Volatile-inhaled anesthetics increase CBF at greater than or equal to 1 minimum alveolar concentration (halothane > enflurane > desflurane = isoflurane > sevoflurane). (MAC)
5. Nitrous oxide increases CBF. The effect is exaggerated when used in conjunction with volatile agents and less when used with IV induction agents other than ketamine.

Question 2

Certo ou Errado

Volatile anesthetics affect both formation and absorption of CSF

Answer 2

Certo
Halothane impedes absorption of CSF but only causes a minimal decrease in CSF formation. Isoflurane facilitates CSF absorption.

Question 3

Local de produção do liquor e volume médio

Answer 3

Production of CSF occurs in the lateral cerebral ventricles by the choroid plexus. About 20 mL/h (500 mL/d) is produced, but absorption at arachnoid villi in cerebral venous sinuses maintains total CSF volume at 100-150 mL.