DILEMMAS IN DAY-TO-DAY CARE
MYTH BUSTING
Is ketamine safe for head-injured patients?
By Bradley Kitts, NRP, FP-C; Jerad Eldred, MS II; Jenifer Belcher Jones, RN, CCRN, CFRN &
Ryan Hodnick, DO, NRP, FAWM
You’re called to rendezvous with an ALS unit at an altitude of 8,300 feet in the mountains. On board is an
altered male in his 50s or 60s who was witnessed crashing his motorcycle at highway
speeds on a windy mountain road.
On arrival, you find your
patient altered and extremely
combative. No vital signs or blood
sugar are obtained secondary to
the patient’s combative state.
He’s noncompliant with a non-rebreather mask and pulls it off.
The patient wasn’t wearing a
helmet and is only wearing jeans
with a T-shirt. He’s noted to have
multiple abrasions to his right
flank, forehead and a deformity
to the right clavicle. He’s otherwise moving all of his extrem-ities with normal strength, but
isn’t making any sense and won’t
cooperate with any commands. You score his
Glasgow coma scale (GCS) as 10.
The transport will take 40 minutes by flight
over remote mountainous terrain at elevations
above 11,000 feet in an unpressurized cabin to
the nearest trauma center. You and your partner decide the patient will need to be intubated for airway protection and to facilitate
both patient and crew safety during transport.
Your initial priority becomes behavioral
control to attain IV access and vital signs. You
and your partner briefly discuss safe sedation
options to gain behavioral control. The options
are benzodiazepines, midazolam (Versed) and
lorazepam (Ativan), or ketamine.
Your safety, as well as the patient’s safety, is
your number one priority. You don’t want to
compromise your patient’s airway or ventila-
tory drive, or drop his blood pressure. Hypoxia
and hypotension will only further complicate
the patient’s condition, and the 8,000 feet
elevation adds even more complexity in terms
of oxygenation.
The patient has multiple noted predictors of a challenging airway including being
5' 8" tall and weighing 320 lbs. (145 kg), with
large amounts of facial hair. Cervical spinal
precautions during airway management will
also have to be observed due to the mechanism of injury, increasing the difficulty of
endotracheal intubation.
With these factors in mind, you decide to
give an induction dose of ketamine intramuscular (IM) first. This will help to safely get
control of the patient, better preoxygenation
before the intubation attempt and also to gain
IV access. The set-up is for a delayed sequence
intubation using ketamine and rocuronium.
The ketamine works within 45 seconds of
IM administration, at which point, a full set
of vital signs and blood glucose is obtained as
well as an IV established. The patient is found
to have oxygen saturations in the low 80s, and
a nasal cannula set at 20 L/min is placed, and
the patient’s respirations are assisted with a
bag-valve mask (BVM).
Equipment is checked and prepared,
including a video laryngoscope, suction and
waveform capnography, which is initially
attached to the BVM.
Once the patient has been saturating in
the upper 90s for a few minutes, it’s decided
to push the rocuronium and attempt intubation. For a full minute, while the rocuronium
is given time to take effect, the
patient continues to be bagged
with proper technique, and a
nasal cannula continues to deliver
oxygen.
The mask is removed and your
partner inserts the video laryngoscope with ease, exposes the
epiglottis followed by the glottic
opening. The endotracheal tube
is delivered without any desatu-ration on the first attempt. Intubation is confirmed with positive
waveform capnography and positive bilateral breath sounds.
The patient is immediately
placed on the ventilator with appropriate settings, and his oxygen saturation kept in the
upper 90s with an end-tidal carbon dioxide
(EtCO2) meticulously maintained between
35–45 mmHg, avoiding hyperventilation. He’s
given another bolus dose of ketamine—this
time via the IV—and started on a ketamine
drip with fentanyl for sedation and comfort.
The patient’s systolic blood pressure remains
in the 120s. He’s transported comfortably on
the ventilator for 40 minutes and arrives without incident.
HOSPITAL COURSE
Upon arrival at the hospital, your patient is
comfortably sedated and hemodynamically
stable with an oxygen saturation of 100%.
As you are finishing your report, the neuro-
surgeon arrives bedside and expresses concern
over your choice of ketamine for sedation. He’s
specifically concerned about ketamine raising
Ketamine retains the patient’s
respiratory drive, doesn’t
decrease blood pressure,
yields no increase in ICP, &
allows for … behavioral
control without apnea.
