15.1

Head Injuries

Chapter 15

Head Injuries

Introduction

The prognosis of brain injuries is good in patients who respond

to simple commands, are not deeply unconscious, and do not

deteriorate. The prognosis is grave in patients who are rendered

immediately comatose (particularly those sustaining penetrating

injury) and remain unconscious for a long period of time. Any

subsequent neurologic improvement may indicate

salvageability and should prompt reevaluation.

Neurosurgical damage control includes early intracranial

pressure (ICP) control; cerebral blood flow (CBF) preservation;

and prevention of secondary cerebral injury from hypoxia,

hypotension, and hyperthemia.

A motor examination of the most salvageable severely braininjured patients will demonstrate localization to central

stimulation and these patients will require expedited treatment.

Immediate intubation with adequate ventilation is the most

critical first line of treatment for a severely head-injured patient.

Evacuation to the nearest neurosurgeon, avoiding diagnostic

delays, and initiating cerebral resuscitation allow for the best

chance for ultimate functional recovery.

Combat Head Injury Types

 Blunt (closed head injury).

 Penetrating.

ο Penetrating with retained fragments.

ο Perforating.

ο Guttering (grooving the skull).

ο Tangential.

ο Cranial facial degloving (lateral temple, bifrontal).
15.2

Emergency War Surgery

 Blast over-pressure CNS injuries.

ο A force transmitted by the great vessels of the chest to the

brain; associated with unconsciousness, confusion,

headache, tinnitus, dizziness, tremors, increased startle

response, and occasionally (in the most severe forms)

increased ICP. Bleeding may occur from multiple orifices

including ears, nose, and mouth.

A combination of multiple injury types are typically involved

in combat-related brain injuries. Those injuries generally involve

the face, neck, and orbit; entry wounds may be through the

upper neck, face, orbit, or temple (Fig. 15-1).

Fig. 15-1. Common vectors of penetrating injury.

Trans-suboccipital

Transtemporal Transfacial/infratemporal

Transorbital

Transfrontal

The subocciput, occiput, and retroauricular regions are

overlooked most. Injuries to these areas can indicate underlying

injury to the posterior fossa, major venous sinus, or carotid

artery, as fragments pass through the skull base. Reconstructing

the fragment path based on combination of plain films and
15.3

Head Injuries

computed tomography (CT) can be challenging. In transorbital,

transtemple, or penetrating injuries that cross the midline, an

underlying injury to intracranial vessels should be suspected with

associated pseudoaneurysms, dissections, or venous sinus injury.

Explosion results in flying fragments, with possible vehicularcollision–associated blunt injuries. Depending on the proximity

to the explosion, a blast over-pressure phenomenon may also

result. In a severely brain-injured patient, more deficits than

indicated by the CT scan may be due to possible underlying

injury to brachiocephalic vessels, shear injury, or the effects of

blast over-pressure with resulting cerebral vasospasm. Plain

films, more useful in penetrating than blunt trauma, may reveal

a burst fracture of the skull indicating the tremendous

perforating force of a penetrating missile. Transventricular

bihemispheric fragment tracts portend a poor prognosis.

Severe head injuries are often seen in combination with

significant chest, abdomen, and extremity injuries. Very rapid

hemorrhage control is the priority in the noncranial injuries;

utilizing damage control concepts and focusing attention on the

head injury. All efforts should be directed toward early diagnosis

and intervention of the head injury.

Traditional Classification of Head Injuries

 Open injuries are the most commonly encountered brain

injuries in combat.

 Closed injuries, seen more often in civilian settings, may have

a higher frequency in military operations other than war.

 Scalp injuries may be closed (eg, contusion) or open (eg,

puncture, laceration, or avulsion).

ο Any scalp injury may be associated with a skull fracture

and/or underlying brain injury.

ο Open scalp injuries bleed profusely, even to the point of lethal

blood loss, but usually heal well when properly repaired.

 Skull fractures may be open or closed, and are described as

linear, comminuted, or depressed.

ο Skull fractures are usually associated with some degree of

brain injury, varying from mild concussion, to devastating

diffuse brain injury, to intracranial hematomas.
15.4

Emergency War Surgery

ο Open skull fractures are prone to infection if not properly

treated.

Mechanisms of Injury

 Primary injury is a function of the energy transmitted to the

brain by the offending agent.

ο Very little can be done by healthcare providers to influence

the primary injury.

ο Enforcement of personal protective measures (eg, helmet,

seatbelts) by the command is essential prevention.

 Secondary injury results from disturbance of brain and

systemic physiology by the traumatic event.

Hypotension and hypoxia are the two most acute and easily

treatable mechanisms of secondary injury.

ο Other etiologies include seizures (seen in 30%–40% of patients

with penetrating brain injuries), fever, electrolyte disturbances

(specifically, hyponatremia or hyperglycemia), and infection.

ο All of the above conditions can be treated.

ο Elevations of ICP may occur early as a result of a spaceoccupying hematoma, or develop gradually as a result of

brain edema or hydrocephalus.

ο Normal ICP is 5–15 mm Hg, with normal cerebral

perfusion pressure (CPP = MAP-ICP) usually around 70–

80 mm Hg.

ο Decreases in perfusion pressure as a result of systemic

hypotension or elevated ICP gradually result in alteration

of brain function (manifested by impairment of

consciousness), and may progress to global brain ischemia

and death if not treated.

Patient Assessment and Triage

During the primary and secondary assessment, attention

should be placed on a complete examination of the scalp and

neck. Fragments that enter the cranial vault with a

transtemple, transorbital, or cross midline trajectory should

be suspected as having associated neurovascular injuries.

Wounds are typically contaminated by hair, dirt, and debris
15.5

Head Injuries

and should be copiously irrigated clean with control of scalp

hemorrhage but not at the expense of delaying definitive

neurosurgical treatment! Scalp hemorrhage can be controlled

with a head wrap, scalp clips, or surgical staples; a meticulous

plastic surgical closure is only appropriate after intracranial

injuries have been ruled out.

 The most important assessment is the vital signs.

 Next is the level of consciousness, best measured and

recorded by the Glasgow Coma Scale (GCS) (see below).

 Triage decisions in the patient with craniocerebral trauma

should be made based on admission GCS score.

ο A GCS < 5 indicates a dismal prognosis despite aggressive

comprehensive treatment and the casualty should be

considered expectant.

GLASGOW COMA SCALE

Component Response Score

Motor Response Obeys verbal command 6

(best extremity) Localizes pain 5

Flexion-withdrawal 4

Flexion (decortication) 3

Extension (decerebration) 2

No response (flaccid) 1

Subtotal (1–6)

Eye Opening Spontaneously 4

To verbal command 3

To pain 2

None 1

Subtotal (1–4)

Best Verbal Response Oriented and converses 5

Disoriented and converses 4

Inappropriate words 3

Incomprehensible sounds 2

No verbal response 1

Subtotal (1–5)

Total (3–15)
15.6

Emergency War Surgery

ο A GCS > 8 indicates that a casualty may do well if managed

appropriately.

♦ In general, neurologically stable patients with

penetrating head injury can be managed effectively in

the ICU with airway and ventilatory support,

antibiotics, and anticonvulsants while awaiting surgery.

♦ An exception to this would be a deteriorating patient

with a large hematoma seen on CT—this should be

considered a surgical emergency.

ο Casualties with GCS 6–8 can be the most reversible, with

forward neurosurgical management involving control of

ICP and preservation of CBF.

 Another important assessment is pupillary reactivity.

A single dilated or nonreactive pupil adds urgency and

implies the presence of a unilateral space-occupying lesion

with secondary brain shift. Immediate surgery is indicated.

ο The presence of bilateral dilated or nonreactive pupils is a

dismal prognostic sign in the setting of profound alteration

of consciousness.

 Radiographic evaluation.

ο Deployable CT scanners in standard ISO shelters are

increasingly available in the field environment. To keep

the scanner operational, a qualified maintenance chief

should be married to the scanner (“crew-chief” concept).

♦ CT is the definitive radiographic study in the evaluation

of head injury, and should be employed liberally as it

greatly improves diagnostic accuracy and facilitates

management.

ο Skull radiographs still have a place in the evaluation of

head injury (especially penetrating trauma).

♦ In the absence of CT capability, AP and lateral skull

radiographs help to localize foreign bodies in cases of

penetrating injuries and can also demonstrate skull

fractures.

♦ This can help direct otherwise “blind” surgical

intervention initially to the side of the head where the

fracture is identified.
15.7

Head Injuries

ο Cervical spine injury is uncommon in the setting of

penetrating head injury.

♦ Closed head injury is commonly associated with injury

of the cervical spine.

♦ Assume the presence of cervical spine injury and keep

the cervical spine immobilized with a rigid collar until

standard AP, lateral, and open-mouth radiographs can

be obtained to exclude injury.

♦ CT once again is useful in evaluating casualties with a

high suspicion for spinal injury.

Management

 Medical.

ο Primary tenets are basic but vital; clear the airway,

ensure adequate ventilation, and assess and treat for

shock (excessive fluid administration should be

avoided).

ο In general, patients with a GCS < 12 should be managed

in the ICU.

ο ICU management should be directed at the avoidance

and treatment of secondary brain injury.

♦ PaO2 should be kept at a minimum of 100 mm Hg.

♦ PCO2 maintained between 35 and 40 mm Hg.

♦ The head should be elevated approximately 30°.

♦ Sedate patient and/or pharmacologically paralyze to

avoid “bucking” the ventilator and causing ICP

spikes.

♦ Broad-spectrum antibiotics should be administered

to patients with penetrating injuries (a thirdgeneration cephalosporin, vancomycin or Ancef,

Unasyn or meropenen if acinetobacter suspected).

♦ Anaerobic coverage with metronidazole should be

considered for grossly contaminated wounds or those

whose treatment has been delayed more than 18 hours.

♦ Phenytoin should be administered in a 17-mg/kg

load, which may be placed in a normal saline

piggyback and given over 20–30 minutes (no more

than 50 mg/min, because rapid infusion may cause

cardiac conduction disturbances).
15.8

Emergency War Surgery

◊ A maintenance dose of 300–400 mg/d, either in

divided doses or once before bedtime, should be

adequate to maintain a serum level of 10–20 μg/L.

♦ Measure serum chemistries daily to monitor for

hyponatremia.

♦ Monitor and treat coagulopathy aggressively.

♦ Monitoring of ICP is recommended for patients with

GCS< 8 (in essence, it is a substitute for a neurologic

examination).

◊ A simple fluid-path monitor usually works well and

allows CSF drainage. It may then be coupled to a

manometer or to a multifunction cardiac monitor

similar to a central venous catheter or arterial line.

Administer prophylactic antibiotic.

Make an incision just at or anterior to the coronal

suture, approximately 2.5–3 cm lateral to the

midline (Fig. 15-2a,b).

A twist drill craniostomy is performed, the

underlying dura is nicked, and a ventricular

catheter placed into the frontal horn of the

lateral ventricle (encountered at a depth of 5 to

6 cm) (see Fig. 15-2b,c). Catheter should be directed

toward the medial epicanthis on the coronal plane,

and the tragus in the sagittal plane.

Even small ventricles can be easily cannulated

by aiming the tip of the catheter toward the

nasion in the coronal plane.

Ventricular catheters are highly preferable;

acceptable substitutes are an 8 F Robinson

catheter or pediatric feeding tube.

A key feature of this technique is to tunnel the

drain out through a separate incision 2–3 cm

from the primary one, thus reducing the risk of

infection.

◊ The goal of management is to maintain a CPP of 60–

90 mm Hg.

◊ A sustained ICP > 20 mm Hg should be treated (Fig. 15-3).
15.9

Head Injuries

Fig. 15-2. Placement of intracranial ventricular catheter.

a

b

c

Midpupiliary

line

Aim for nasion or

ipsilateral medial

epicanthus

Aim for tragus

Tragus line
15.10

Emergency War Surgery

Fig. 15-3. Levels of intervention to reduce ICP.

Sedation, head elevation, and paralysis.

CSF drainage if a ventricular catheter is in place.

Hyperventilation to a PCO2 of 30 to 35 mm Hg only

until other measures take effect. (Prolonged

levels below this are deleterious as a result of small

vessel constriction and ischemia.)

Refractory intracranial hypertension should be

managed with an initial bolus of 1g/kg of

mannitol and intermittent dosing of 0.25–0.5 g/

kg q4h as needed.

 Aggressive treatment with mannitol should be

accompanied by placement of a CVP line or even

a PA catheter because hypovolemia may ensue.

Any patient who develops intracranial hypertension

or deteriorates clinically should undergo prompt

repeat CT.

◊ Mild hypothermia may be considered in isolated

head injury, but avoid in the multitrauma patient.

♦ Treat hypovolemia with albumin, normal saline,

hypertonic saline, or other volume expanders to create

a euvolemic, hyperosmolar patient (290–315 mOsm/L).

♦ Blast over-pressure CNS injuries.

Levels of Intervention

Pentobarbital

or Thiopental Load

Hemicraniectomy/Duraplasty

Mild Hypothermia (34°–36°C) should be considered in isolated head

injury but should be avoided in multi-trauma

CSF Drainage via Ventriculostomy 

Mannitol/Lasix (possible 3.0% Hypertonic Saline)

Moderate Head-Up Posture (30°)

Adequate Sedation/Analgesia (Versed, Fentanyl, Morphine, Propofol)
15.11

Head Injuries

◊ Supportive medical therapy is usually sufficient.

Only in rare cases is an ICP monitor, ventriculostomy,

or cranial decompression necessary. In the absence

of hematomas the use of magnesium has been

beneficial. Structures particularly sensitive include

optic apparatus, hippocampus, and basal ganglia.

Delayed intracranial hemorrhages have been

reported. Additionally, these patients have a higher

susceptibility to subsequent injury and should be

evaluated at a level 4/5 facility. Repetitive injury and

exposure to blast over-pressure may result in

irreversible cognitive deficits.

 Surgical

ο Goals: prevent infection and relieve/prevent intracranial

hypertension.

ο Indications for emergent exploration.

♦ Space-occupying lesions with neurological changes (eg,

acute subdural/epidural hematoma, abscess).

♦ Intracranial hematoma producing a > 5 mm midline

shift or similar depression of cortex.

♦ Compound depressed fracture with neurological changes.

♦ Penetrating injuries with neurological deterioration.

ο Relief of ICP with hemicraniectomy/duraplasty/

ventriculostomy.

♦ A large trauma flap should be planned for the

evacuation of a mass lesion with significant underlying

edema in the supratentorial space.

♦ The flap should extend a minimum of 4 cm posterior to

the external auditory canal and 3–4 cm off midline.

Exposing the frontal, temporal, and parietal lobes allows

for adequate cerebral swelling and avoids brain

herniation at the craniotomy edge.

♦ A capacious duraplasty should be constructed with

a subdural ICP/ventricular catheter in place,

allowing monitoring and drainage from the injured

hemisphere.

ο Shave hair widely and scrub and paint the scalp with

betadine.

ο General anesthesia for major cases.
15.12

Emergency War Surgery

ο Administer empiric antibiotics (third-generation

cephalosporin).

ο Positioning can be adequately managed with the head in

a doughnut or horseshoe-type head holder. For unusual

positioning of the head, such as to gain access to the

subocciput, use a standard three-point Mayfield fixation

device.

ο Make a generous scalp incision to create an adequate flap.

♦ The flap should have an adequate pedicle to avoid

ischemia.

♦ Retraction of the scalp flap over a rolled laparotomy

sponge will avoid kinking the flap, which also may lead

to ischemia.

ο The skull should be entered through a series of burr holes

(Fig. 15-4) that are then joined to create a craniotomy flap

(Fig. 15-5a).

Fig. 15-4. Cranial landmarks and location of standard burr holes.

5–6 cm

1

cm

2 cm 4 –5 cm

zygoma
15.13

Head Injuries

Fig. 15-5. Craniotomy flap and exposed hematoma.

♦ Burr holes alone are inadequate to treat acute

hematomas, but are of diagnostic utility in the absence

of CT scanner. Exploratory burr holes may miss

subfrontal or interhemispheric hematomas (Fig. 15-6).

Fig. 15-6. Hematomas missed with routine exploratory burr holes.

Small temporal

craniotomy

Dashed lines

(dural incision sites)

a b
15.14

Emergency War Surgery

♦ The bone work may be done with a Hudson brace

and Gigli’s saw, though a power craniotome is certainly

preferable if available (see Fig. 15-5a).

ο A dural opening, using the entire expanse of the cranial

opening (with enough edge left to close the dura at the

end of the case), should be created.

♦ The base of the dural opening should be on the side near

any neighboring major venous sinus to avoid injury to

large draining veins and aggravation of cerebral edema.

ο The hematoma should then be gently evacuated with a

combination of suction, irrigation, and mechanical removal

(see Fig. 15-5b).

ο Meticulous hemostasis should be achieved and the dura

closed.

ο Approach to penetrating injury with neurologic changes

is aimed at removal of devitalized brain and easily

accessible foreign bodies.

♦ Perform copious irrigation with an antibiotic solution

(such as bacitracin) and a concerted attempt made to

achieve watertight dural closure (again, using

pericranium, among others, as needed).

♦ Tension-free scalp closure is also essential, but

replacement of multiple skull fragments in an attempt

to reconstruct the skull defect is not appropriate in the

battlefield setting.

◊ Excellent results can be achieved with cranioplasty

after evacuation out of the theater and a sufficient

delay to minimize risk of infection.

ο If a duraplasty is required, pericranium, temporalis fascia,

or tensor fascia lata may be used.

ο Tack-up sutures should be placed around the periphery

and in the center of the dural exposure to close the dead

space and discourage post-operative epidural hematoma

formation.

ο Replace bone flap and secure with wire or heavy suture.

♦ If severe brain swelling precludes replacement of the

bone flap it can be discarded or preserved in an

abdominal-wall pocket.
15.15

Head Injuries

ο The galea of the scalp should generally be closed separately

with an absorbable suture, and with staples used to close

the skin.

♦ A single layer closure with heavy monofilament nylon

is acceptable but should definitely include the galea,

with the sutures remaining in place at least 10 days.

♦ A subgaleal or epidural drain may be used at the

discretion of the surgeon.

ο Apply a snug dressing using roller bandages around the

entire head.

Evacuation of the Severely Head-Injured Patient

The trip is always longer than advertised. Transport only

patients who can be expected to survive 12–24 hour movements,

due to unexpected delays, route changes, or diversion in the

tactical situation. A post-operative, craniotomy patient should

first be observed for 12–24 hours prior to transport. Evacuating

immediately may lead to the inability to treat delayed postoperative hematomas that may occur.

ο All patients with GCS < 12 are ventilated.

ο Patients with GCS < 8T require ICP monitoring.

ο Ventriculostomies should be placed, position confirmed,

secured, and working prior to departure.

ο The critical care evacuation team must be confident in the

ability to medically treat increased ICP and troubleshoot

the ventriculostomy.

ο Medical management of ICP in flight is limited to the use

of head-of-bed elevation (30°–60°), increased sedation,

thiopental, ventricular drainage, and mild

hyperventilation. Loading a patient head-of-bed first limits

the effect of takeoff on ICP.

ο The escort of a severely head-injured patient must be able

to manage the airway, ventilator, IV pumps, IV medicines,

suction, in addition to ICP and CBF.

ο Patients with possible intracranial pathology who may

deteriorate inflight should be neurosurgically maximized

on the ground prior to departure (eg, placement of a

ventriculostomy or evacuation of a hematoma).
15.16

Emergency War Surgery

ο If a head-injured patient (GCS > 12) deteriorates in flight

and is not already intubated, intubation should be

performed and planned. Ensure rapid sequence intubation

medicines, IV access, and airway equipment (especially

Ambu bag, ventilator) are working and available.

ο The most difficult part of an evacuation is from the CSH

to the CASF/MASF. Typically, battery life of the ventilator

and monitors, and supplies of oxygen can be depleted

before the exchange of the patient to the CASF/MASF.

Although electric power is available on Black Hawks and

FLA (ground ambulance), it is rarely used.

ο Prior to departure from the CSH the following precautions

must be taken by the escort:

♦ Ensure knowledge of patient injuries and clinical course.

(Have narrative summary and pertinent radiographs

in hand.)

♦ Ensure adequate medicines for minimum of 3 days.

♦ Ensure monitors, ventilators, and suction and IV pumps

all have adequate battery life.

♦ Ensure adequate oxygen supplies, and that the escort

has the familiarity with and the ability to switch oxygen

tanks.

♦ Have an alternate battery-operated, tactical light source

to read monitors during transport.

♦ Assemble patients on the stretcher to avoid iatrogenic

injuries to limbs, organizing tubes, lines, electrical leads,

and wires so as not to become snared during

movements. (When available, a SMEAD shelf attached

to the stretcher allows monitors to be secured and

elevated off the patient’s body.)

♦ Ensure that limbs (toes and fingers) and torso are

covered and insulated during the trip to prevent

hypothermia.

♦ During movements ensure central lines, a-lines, and

ventricular catheters do not become dislodged. Ensure

lines and tubes are sutured or otherwise secured.

♦ Ensure the ventriculostomy does not develop an airlock. Venting the tublet can be performed with a 21-

gauge needle.