Neurotrauma (Neurosurgery by Example)-Oxford University Press (2020)

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intracranial pressure (ICP) monitoring in patients with GCS of less than 8 and an ab-
normal head CT, or patients with a normal head CT if they had two or more of the

inclusion criteria: age older than 40, motor posturing, SBP less than 90 mm Hg. While

these characteristics frequently describe the majority of patients who receive ICP mon-
itoring at our institution, the most recent BTF guidelines removed these criteria as the

relevant studies did not meet evidence standards. The only recommendation for moni-
toring is currently that ICP monitoring may reduce in-hospital and 2-week mortality.

The gold standard ICP monitor is an external ventriculostomy (EVD), and the BTF

guidelines emphasize that these are favored because they allow for monitoring and treat-
ment of ICP via CSF drainage, and they can be recalibrated, unlike other available

monitors. The recommendation is to treat ICP of more than 22 mm Hg because ICP
above this threshold is associated with increased mortality.
Prior to any procedures, it is imperative that a full set of labs be checked to ensure

platelets and coagulation markers are within normal limits. If possible, a medication his-
tory should be obtained specifically asking about antiplatelet and anticoagulation agents.

Appropriate reversal agents should be administered as needed. In addition, any patient
with concern for elevated ICP should have a chem 7, full electrolyte panel, and serum
osmolality drawn on admission to aid treatment planning.
The location of EVD placement requires additional consideration in patients with
traumatic injuries or fractures. In general, we prefer right-sided ventriculostomies to
minimize disruption of eloquent cortex. In cases with significant left-side hemorrhage
or injury, we consider an ipsilateral EVD to avoid further injury should a peri-catheter
hemorrhage arise.

Patients undergoing medical management of elevated ICPs should have central ve-
nous access and arterial lines placed to allow administration of medication and mainte-
nance of blood pressure goals in accordance with BTF guidelines (SBP >100 patients

50–69, >110 for patients 15–49 and >70). Consideration may be given to placement of
a Swan-Ganz catheter in patients who require barbiturate coma for ICP management.
Following placement of the EVD, the patient’s ICPs were noted to be 25–30 despite
drainage of CSF. Additional medical interventions were begun. Short-term temporizing
approaches include hyperventilation to decrease Pco2

and sitting the patient upright.
These interventions should be instituted while additional medications are being obtained
and should not be used as the sole means of addressing persistently elevated ICP. The only
recommendation in the 4th edition BTF guidelines regarding hyperventilation is Level
IIb, that prolonged prophylactic hyperventilation is not recommended. Previous editions

specifically recommended hyperventilation as a temporizing measure. While this recom-
mendation was removed because it was based on literature that did not meet inclusion

criteria for the 4th edition (case series only), it may still be a useful temporizing measure
while medications are being obtained or operative intervention is being arranged.
The benefit of ICP monitoring via an EVD includes the ability to drain CSF for
management of elevated ICP: the available guidelines are Level III recommendations
that continuous drainage via an EVD zeroed at the midbrain may be more effective than
intermittent drainage and that CSF drainage may be considered in patients with GCS of
less than 6 in the first 24 h. This is a new topic in the 4th edition of the guidelines, and
additional high-quality studies are needed to enable more thorough recommendations
in future editions.

The most recent BTF guidelines state that while hyperosmolar therapy may de-
crease ICP, there is insufficient evidence to recommend a specific agent (i.e., mannitol,

hypertonic saline) for this therapy. Earlier editions of the guidelines stated that man-
nitol in doses of 0.25–1 g/kg was effective in reducing ICP and recommended using

mannitol either in patients with evidence of elevated ICP on intracranial monitor or
in patients with clinical evidence of herniation syndromes or progressive neurological
Pharmaceutical methods of treating elevated ICP include intermittent boluses of
narcotics (our institution frequently uses fentanyl), continuous drip of these medications,
continuous drip of sedating agents (i.e., Precedex, propofol), or the use of barbiturates
to induce burst suppression on EEG for intractable ICPs. Level IIb recommendations
suggest barbiturate-induced burst suppression should not be used prophylactically but
may be used for refractory ICP provided hemodynamic stability is maintained. Propofol
is recommended for control of ICP, with the caveat that it does not improve mortality

or 6-month outcomes. In patients being treated with high-dose propofol for ICP man-
agement, it is important to monitor creatinine, creatinine kinase, and clinical signs of

renal function to ensure that propofol infusion syndrome (PRIS), which carries a high
mortality rate in itself, does not occur.

The BTF guidelines do not recommend prophylactic hypothermia; however, hy-
pothermia remains an option in the ICP management pathway for patients with re-
fractory elevated ICP. Hypothermia may be achieved with cutaneous cooling pads or

via a central venous catheter system. Central access may minimize shivering but does
not obviate it. Our protocol is to begin by cooling patients to 35°C, using BuSpar and

magnesium continuous infusions as prophylaxis against shivering. In patients who de-
velop significant shivering, we attempt counter-warming with heated air blankets (i.e.,

Bair Hugger). If this fails, and if shivering affects ICP management, a paralytic infusion
such as rocuronium is strongly considered. Of note, patients with severe shivering at
35°C may be cooled to 33°C, which minimizes the physiologic shivering response.

Patients who are undergoing therapeutic hypothermia treatment, who do not have clin-
ical shivering, but continue to have elevated ICPs, may be having micro-shivering and

may also benefit from a paralytic. During hypothermia, the physiologic response is to
force potassium intracellularly, leading to hypokalemia on daily lab checks. However, as
rewarming will reverse this process, we recommend judicious repletion of potassium in
these patients, with a goal around 2.5–3.0 provided there are no EKG changes, to avoid
severe hyperkalemia upon rewarming.


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