CASE OF THE MONTH
the patient’s intracranial pressure (ICP).
You respectfully discuss your treatment
choices with the neurosurgeon, explaining to
him how your guidelines are evidence-based,
up-to-date and that there are studies debunking concerns for increasing ICP in head
trauma patients.
The patient is diagnosed with a right-sided
subdural hemorrhage, as well as a right clavicle fracture and multiple right-sided broken
ribs. He’s taken to the operating room, and a
craniotomy is performed to decompress his brain and stop the bleeding. He’s admitted to the ICU and
spends a month in the hospital where
he makes an excellent recovery.
DISCUSSION
Traumatic brain injuries (TBIs) are
commonly encountered in the prehospital setting. In the United States,
approximately 2. 5 million victims
of TBI are seen in EDs each year
and, of those, 50,000 result in death
and 235,000 are hospitalized. The
Excellence in Prehospital Injury Care (EPIC)
Traumatic Brain Injury Project shows that
interventions performed in the first minutes
after the injury are imperative to the patient’s
survival and long-term outcome.
1
Prevention of both hypoxia and hypotension can prevent further injury to the brain
after the initial insult has occurred. Many of
these cases require air way protection and good
ventilatory support.
Drug choices become important regarding
airway management, sedation, analgesia and
hemodynamic integrity, as many may cause
transient hypotension and/or apnea. Care-
ful drug choices are an imperative part of a
good airway management strategy, as well as
post-sedation considerations.
Ketamine is one of the few sedation and
analgesic drugs that can help prevent drug-induced hypotension and hypoxia when properly dosed. In this case, it served multiple
important functions.
First, it served as a means to safely gain
behavioral control to facilitate further treatment and assessment without the loss of airway
reflexes. Ketamine is well known for its role in
gaining behavioral control with preservation
of airway reflexes and can be given IV, IM and
intranasal or intraosseous, which is very useful
as an IV is often near impossible to place in
combative patients. Gaining behavioral control allowed providers to perform an accurate
physical assessment including complete vital
signs and facilitated important procedures in
the patient’s treatment course including IV
access and placement of an advanced airway.
Secondly, ketamine provides both analgesia
and sedation for the patient not only during
airway management, but it also provided con-
tinuous sedation in the form of a drip.
Third and importantly, ketamine isn’t asso-
ciated with the transient drop in blood pres-
sure or apnea that’s associated with other
drugs such as midazolam (Versed), loraze-
pam (Ativan) or propofol (Diprivan), making
it an ideal drug in this situation.
2
So where does the myth that ketamine
causes increased ICP come from? In the
1970s there were a series of six stud-
ies performed that reported an asso-
ciation with increased ICP. All of
this research is comprised of case
reports and small case-control stud-
ies. These publications were con-
founded by patients with abnormal
cerebrospinal fluid pathways, which
included patients with aqueductal
stenosis and obstructive hydroceph-
alus.
3 None of these studies directly
evaluated patients with TBIs.
Unfortunately, the myth that
ketamine was contraindicated with
TBIs has persisted until relatively recently.
Current studies directly evaluating the
effects of ketamine on ICP in TBI patients
have debunked this myth, and ketamine
now considered one of the best agents to
facilitate airway management in the head-
injured patient.
4
TEACHING POINTS
As illustrated by this case, patients who are
combative secondary to a TBI are notoriously
difficult to manage. Priorities in TBI patients
include: maintaining mean arterial pressure
(MAP), preventing hypoxia and hyperventi-
lation, and mitigating increases in ICP.
5
Ketamine assists in accomplishing these
priorities. Ketamine retains the patient’s respi-
ratory drive, doesn’t decrease blood pressure,
yields no increase in ICP, and allows for an
additional advantage over other sedation med-
ications: behavioral control without apnea.
6, 7
Furthermore, due to the ability to administer ketamine via IM or intranasal route and
the fast onset, control of the patient can be
obtained quickly and without the need of IV
access.
8 Quick control also aids in controlling
life threats, like significant bleeding, and allows
for complete patient assessment.
Lastly, ketamine has a high therapeutic
index that allows some flexibility in dosing
necessary when obtaining an accurate body
Unfortunately, the myth
that ketamine was
contraindicated with
TBIs has persisted until
relatively recently.
Interventions performed in the first minutes after injury are imperative to the patient’s survival and
long-term outcome. Photo courtesy Ryan Hodnick
