Neurocritical Care
Burst suppression on continuous EEG (target usually is 2–5 bursts/minute) is a surrogate end point
for need of additional pentobarbital doses.
A bolus dose is required concomitantly with an infusion titration because of its long half-life
(24–48 hours) and rapid redistribution.
Monitoring
ICP
EEG and burst occurrence per minute
Serum concentrations do not correlate well with ICP response and should not be used to titrate
infusion. May be useful when therapy has been discontinued as part of brain death examination (to
rule out continued intoxication from pentobarbital)
| d. | Due to the risk of metabolic acidosis from propylene glycol accumulation, serum chemistry, pH, |
|---|
and osmolality should be monitored during prolonged treatment.
Adverse effects
Hypotension as the result of several different causes
Propylene glycol diluent
ii.
Direct vasodilator
iii.
Reduction in sympathetic tone because of metabolic suppression
iv.
Cardiac depressant (particularly with high doses and duration greater than 96 hours)
Bradycardia
Decreased GI motility and ileus
Difficulty with enteral nutrition
ii.
Caloric needs are usually around 80%–90% of basal energy needs, so a lower flow rate for
enteral nutrition is permissible.
iii.
Ideally, would use an elemental or semi-elemental nutrition product because stooling is rare
on pentobarbital infusion
| d. | Infection (particularly pneumonia) |
|---|
Immunosuppression
Withdrawal seizures may occur.
Metabolic acidosis due to propylene glycol toxicity
Patient Case
his brain reveals a large right temporal subdural hematoma, an overlying skull fracture, and a left temporal
contusion. His post-resuscitation GCS is E1-M4-V1T. An ICP monitor is placed with an opening pressure
of 32 mm Hg, and CPP is 53 mm Hg. Serum laboratory values include Na 139 mEq/L, K 3.6 mEq/L, BUN
42 mg/dL, SCr 2.4 mg/dL, glucose 178 mg/dL, WBC 14.8 × 103 cells/mm3, pH 7.46, and Pco2 34 mm Hg.
Which is the best initial therapy for this patient’s elevated ICP?
these are “living guidelines” that will be updated continuously. Unfortunately, the newest guidelines reflect
only recommendations with high levels of evidence. Therefore, the 2007 guidelines may be needed to
review practical recommendations (based on all levels of evidence) for complications in patients with a TBI.