Summary of Anesthetics
|
Drug |
CMR |
CBF, CBV, ICP |
Impair Autoreg |
EEG Burst suppr? |
Alter SSEP |
Alter BAER |
Alter MEP |
Comments |
|
Volatile agents (isoflurane, sevoflurane, desflurane |
Decrease |
Increase |
Yes |
Yes |
Yes |
No |
Yes |
All effects dose dependent; hyperventilation blunts CMR, CBF, CBV, ICP effects; discontinue before ECoG |
|
Nitrous Oxide |
? |
Increase |
Yes |
No (seizure surgery) |
Yes |
No (unless incr middle ear pres) |
Yes (less than volatile) |
Barbiturates, Narcotics, Propofol blunts CMR, CBF, CBV, ICP effects; use with <0.5 MAC volatile anesthetic to minimize effect on SSEP |
|
Thiopental, Propofol |
Decrease |
Decrease |
No |
Yes |
Some |
No |
Yes |
Propofol decreases systemic blood pressure; stop 20 min prior to ECoG |
|
Etomidate |
Decrease |
Decrease |
No |
Yes* |
Yes (INC amp)** |
No |
Minimal |
Cardiac stabilizer; *Bolus causes spike wave activity; **Incresases amplitude of SSEP so might mask injury |
|
Ketamine |
Increase |
Increase* |
No |
No |
Yes (INC amp) |
No |
Minimal |
*Significant increase in ICP |
|
Dexmedetomidine (alpha agonist, mostly alpha2; produces sleeplike state) |
No effect |
Decrease* |
No |
No |
No |
No |
No |
*Little effect on ICP; causes hypertension if given too quickly |
|
Benzodiazepines |
Decrease |
Decrease |
No |
No |
Some |
No |
Some |
Used for sedation or seizure |
|
Opioids |
No effect |
No effect |
No |
No |
Slight |
No |
Minimal |
CMR does decrease with very high doses |
|
Depolarizing Muscle Relaxants (Succinylcholine) |
No effect* |
No effect* |
No |
No |
No |
No |
Yes |
*Initial bolus can cause transiently increase CMR, CBF and ICP (blunted by lidocaine) |
|
Non-Depolarizing Muscle Relaxants (-curonium) |
No effect |
No effect |
No |
No |
No |
No |
Yes |
Reversed by neostigmine |