40. Traumatic Brain Injury Management and Basic Neurosurgery in the Deployed Environment

Purpose

These guidelines are not intended to supplant physician judgment. Rather, these guidelines are intended to provide a basic framework for those less experienced with the delivery of care in this setting to the brain injured patient, as well as to educate and provide insight to others on the delivery of care in a restrictive environment.

Background

Trends

Significant head trauma presents as a complicating injury in at least a third of all trauma related deaths in the United States.¹ In the combat environment, multiple trends have been observed in the management of traumatic brain injury (TBI) since 2003, warranting the standardization of care for these casualties.

• Positive outcomes are achieved through rapid evacuation from the battlefield, far forward medical management, timely neurosurgical intervention, meticulous critical care, and a dedicated rehabilitative effort.^2-7
• In recent U.S. military experience, a large percentage of patients who have presented with severe head injury are Host Nationals.
• There is a sizable body of foundational literature from military trauma centers confirming that patients with severe closed and penetrating brain injuries who received timely and aggressive neurosurgical and neuro-critical care interventions had favorable outcomes.^2-4
• Following Role 3 theater hospital treatment, transfer of the patient will occur to a hospital serving patients of their national origin. Experience has demonstrated that often patients who fail to quickly recover to independent or minimally assisted living have typically not been treated aggressively thereafter by some national healthcare systems. Decisions made for the care of these patients are to be made in light of the available continuum of care for the patient in their nation of origin.

Classification

The classification of head injury has prognostic and care eligibility implications in the combat environment. Head injured patients are classified according to their Glasgow Coma Score (GCS).

• Mild: GCS 13–15
• Moderate: GCS 9–12
• Severe: GCS 3–8

Currently, neurosurgical care is available at Role 3 facilities.

Eligibility For Neurosurgical Care of Role 3 Facilities

Given the restrictive nature of neurosurgical resources in the combat environment, the following guidance is provided for determining eligibility for neurosurgical care. A subsequent independent study confirmed the validity of the previously observed favorable outcomes by comparing combat casualties with isolated severe brain injuries to matched civilian counterparts.⁴

Coalition

• Coalition forces with mild head injuries that do not clear within 24 hours may require transfer for formal evaluation by Computed Tomography (CT) and/or a neurosurgeon.
• All Coalition casualties with any penetrating head injury, open skull fracture, or moderate or severe head injury should be referred for neurosurgical evaluation.
• Patients with head trauma and unexplained neurologic deficits should be referred for neurosurgical evaluation.

Host Nationals

• Management of host nationals should be in accordance with medical rules of eligibility established for that AOR.
• Host National patients with mild head injury should be managed locally and should not be transferred to Role 3 facilities unless transfer is first discussed and coordinated with the receiving neurosurgeon or Chief of Trauma.
• Moderate head injury may be referred to Role 3 facilities with neurosurgical capability for definitive care.
• Transfer of Host Nationals with a severe head injury is based on mission, tactical situation, and resource availability and must be preceded by direct communication and discussion with the neurosurgeon, as these casualties may need to be managed expectantly.

Early Evaluation and Treatment

The initial management of the patient with significant head trauma begins with addressing life-threatening injuries and resuscitation in accordance with published Advanced Trauma Life Support (ATLS) protocols.⁸

• Blood products are preferred over albumin or Hespan if colloids are needed.⁹
• For those patients not requiring massive transfusion protocol or other blood products, normal saline is the preferred crystalloid solution, avoiding hypotonic fluids.
• Normoventilation with a goal PaCO₂ of 35-40 mmHg should be maintained.
• Prophylactic hyperventilation is not recommended, but may be used as a temporizing measure to reduce intracranial pressure in the setting of suspected herniation.¹⁰
• Routine prophylactic antibiotics are unnecessary for isolated closed head injuries, but penetrating injuries, open skull fractures, or pre-operative patients should be placed on antibiotics.¹¹ Antibiotic recommendations for the first level of surgical care include use of either cefazolin 2 gm IV every 6-8 hours or clindamycin 600 mg IV every 8 hours. If a penetrating head injury appears grossly contaminated with organic debris, consider addition of metronidazole 500 mg IV every 8-12 hours.¹¹
• Monitor glucose every 6 hours. Goal is to maintain glucose < 180 mg/dl but avoid hypoglycemia.¹²
• Steroids should be avoided in head injured patients as they have not shown outcome benefit and increase mortality in patients with severe head injury.^10,13
• Manage hypotension maintaining SBP at ≥110 mm Hg in patients with suspected TBI's to decrease mortality and improve outcomes.¹⁴ A systolic blood pressure of less than 90mm Hg is the single risk factor most highly associated with mortality in brain trauma.¹⁵
• A common strategy for management of hypoxemia has been goal of SaO₂ >90% and PaO₂ >60 mmHg. 10 However, in the recent combat experience, given frequent handoffs, equipment challenges, varying levels of provider experience, etc., SaO₂ and PaO₂ have been managed with goals of >93-95 and >80, respectively.
• Document serial neurological exam findings, including:
  • Glasgow Coma Score
  • Pupil size and reactivity
  • Presence of gross focal neurologic signs and/or deficit.

Transporting Patient

Due to the requirement to move the coalition patient with severe head trauma to Role 4 facilities usually out of theater, early and safe transport of these patients should involve consideration of several factors.

Sedation

For casualties transferring to Role 3 facilities with neurosurgical capability, avoid long-lasting sedation or paralysis. However, at no time should medication selection override the need to safely transport the casualty.

• Vecuronium is preferred for paralysis because it is readily available in the far forward environment and does not require refrigeration. Bolus dosing is preferred over continuous infusion.
• Propofol is preferred for sedation.¹⁰
• Pain management with intermittent narcotics is preferred over continuous infusion.

Intracranial Hypertension

Despite recent controversy in terms of placement of invasive monitors to measure intracranial pressure, treatment of known or suspected intracranial hypertension remains a cornerstone of therapy in patients with severe brain injury.¹⁶

If treatment for intracranial hypertension is needed prior to transfer, then initiate hyperosmotic therapy with one of the following:

1. 3% Saline17 (Appendix B)
   • Consider 250ml bolus of 3% saline and then infuse 3% saline at 50-100ml/hr for resuscitation Enroute to the Role 3 facility.
   • Goal serum Na level is 150-160. Caution is advised if patient presents in a hyponatremic state.
   • Place central venous access to administer hypertonic saline and vasoactive medications particularly if it is anticipated to be needed long term.
2. Mannitol. Consider using mannitol if there is further deterioration in neurological status or as an alternative to 3% NaCl.
   • Mannitol 1g/kg bolus IV followed by 0.25g/kg IV push q4 hrs.¹⁰
   • In the trauma population, replace brisk urine output following mannitol administration with isotonic fluids.
   • Avoid mannitol in hypotensive or under-resuscitated casualties
   • When treating patients with osmotic agents, monitor serum sodium on a frequent basis.

Antiepileptic Medications

• Seizures are not uncommon after severe brain trauma. Anticonvulsant prophylaxis should be administered to avoid the hemodynamic changes and increased cerebral metabolic activity associated with seizure activity.
• Give antiepileptic medication for seizure prophylaxis for the first 7 days after a moderate or severe TBI.¹⁰ Reasonable options include phenytoin, fosphenytoin, or levetiracetam.¹⁸ (Appendix A)

Other Precautions

1. Avoid and treat hyperthermia
2. Elevate head of bed to 30-45° or use reverse Trendelenburg position for suspected concomitant spine/spinal cord injuries.
3. Gastric ulcer prevention should be provided.
4. Consider enteral nutrition according to Nutritional Support Using Enteral and Parenteral Methods.¹⁹

Aeromedical Evacuation Considerations

Intracranial Pressure

1. Observation in theater may be warranted for patients with borderline ICP measurements due to stresses of flight including vibration, temperature, noise, movement, light, hypoxia, and altitude.²⁰
2. ICP monitoring is recommended during aeromedical evacuation for patients who would meet the requirements as stated above.
3. Do not remove a functional ICP monitor in the immediate period prior to aeromedical evacuation. This provides information to the CCAT team that can direct in flight treatment. Furthermore, it offers a level of safety in terms of stable ICP in patients who may otherwise require sedation or not have a reliable neurological exam.
4. In addition, patients who have ongoing resuscitative requirements and an intracranial lesion or the potential for development of cerebral edema may require delayed evacuation. For example, this is seen with patients who have significant burns requiring resuscitation by the JTS Burn CPG²¹ and have an intracranial mass lesion or cerebral edema.

Drains

Do not remove drains in the immediate period prior to aeromedical evacuation.

Pneumocephallus

• The effect of increasing altitude on contained air within the body, including the cranium, will potentially result in expansion of the pneumocephalus. This factor should be considered carefully by the treating neurosurgeon and coordinated with CCATT to discuss the potential risk; this is particularly true for those who have not undergone a decompressive craniectomy prior to the flight.
• All patients should be transported with head of bed elevation or reverse Trendelenberg at 30-45°. Typically USAF doctrine is to load all patient’s feet first into the aircraft. ²² In a patient with TBI, the aeromedical transport physician may consider loading head first, to maintain head elevation.

Risk of Venous Thrombosis

• Starting DVT chemoprophylaxis on a US/Coalition patient with a moderate to severe head injury should be done in consultation with the theater neurosurgeon.
• Patients with moderate or severe head injury require routine DVT prophylaxis (i.e. sequential compression device).
• Enoxaparin 30mg sq BID or SQ heparin may be used as chemoprophylaxis providing patient does not have potential hemorrhagic issues.^10,23,24

Surgical Management of Moderate to Severe Head Injuries

Non-operative management of intracranial hematomas should be followed with serial imaging and clinical examinations.

Surgical intervention is often indicated in the management of patients with severe brain trauma. This includes operative care such as evacuation of space-occupying hematomas via craniectomy or craniotomy, as well as placement of intracranial monitors.

Intracranial Pressure Monitoring

1. Management of severe TBI patients using information from ICP monitoring is recommended to reduce in-hospital and two-week post-injury mortality.¹⁴
2. Intracranial pressure (ICP) monitoring should be considered in all salvageable patients with a severe brain injury and an abnormal CT showing one or more of the following: Hematomas, contusions, swelling, herniation, or compressed basal cisterns.¹⁰
3. ICP monitoring is indicated in patients with severe TBI and a normal CT if 2 or more of the following are noted: Age >40, unilateral or bilateral posturing, systolic blood pressure <90 mm Hg.¹⁰
4. Options for ICP monitoring.¹⁰
   • External Ventricular Drain
   • Parenchymal ICP monitors. Currently Codman ICP monitors are the only device with aeromedical certification approved for USAF aircraft.
5. Goal ICP is <22 mmHg.¹⁰
6. Target Cerebral Perfusion Pressure (CPP) for survival and favorable outcomes is between 60-70 mm Hg. Whether 60 or 70 mmHg is the minimum optimal CPP is unclear and may depend on the auto regulator status of the patient.¹⁴

Operative Care: Evacuation of Hematoma

Epidural Hematoma²⁵

1. All epidural hematomas > 30cc should be surgically evacuated regardless of the patients GCS
2. EDH <30cc and with less than 15mm thickness and less than 5 mm midline shift with a GCS >8 without a focal deficit may be managed non-operatively with appropriate monitoring in the ICU setting.

Subdural Hematoma²⁵

1. Craniotomy for evacuation of an acute SDH with a thickness >10mm or midline shift > 5mm regardless of the patient’s GCS. Give consideration for expectant management with Host Nationals who present with a GCS of <8.
2. Craniotomy for evacuation of acute SDH with a thickness <10mm and shift <5 mm if there is a decrease in GCS of 2 or more, worsening pupillary exam, and/or and ICP greater than 20mm Hg.

Traumatic Parenchymal Lesion²⁵

1. Craniotomy with evacuation of a hematoma in a patient with a GCS of 6-8 with frontal or temporal contusions greater than 20 cc in volume with midline shift or at least 5mm and/or cisternal compression on CT
2. Patients with lesions greater than 50 cc in volume in a salvageable patient.

Posterior Fossa Mass Lesion²⁵

Mass effect on non-contrast CT or with neurological dysfunction or deterioration referable to the lesion should undergo operative intervention as soon as possible.

Exploratory Burr Holes

Exploratory burr holes have limited practical utility. They should only be performed after consultation with a neurosurgeon if possible and at a location where CT scan is not available to better guide management.

1. Indications for consideration of burr holes²⁶
   • No immediate neurosurgical capabilities
   • No CT scan available
   • Deteriorating neurological exam that can be localized
   • Unilateral pupillary changes

Traumatic Aneurysms

High index of suspicion is required for penetrating injuries at the skull base or across known major vascular territories.⁷

Debridement

Removal of devitalized brain tissue is an option in penetrating head injuries and in select cases of open skull fractures.²⁶

Foreign Body Removal

The routine pursuit of individual foreign bodies (e.g. bullets, metallic fragments, bone) within the brain is not advisable, but should be left to the discretion of the neurosurgeon. Removal of fragments from the sensory, motor, or language cortex may reduce the risk of posttraumatic epilepsy.²⁷

Dural Management

Primary dural closure or limited duroplasty should be done cautiously at initial operation as ongoing edema progresses after penetrating or severe blunt trauma. Dura can be reconstructed with temporalis fascia or fascia lata.²⁶

Decompression

Surgical decompression, or craniectomy, should be strongly considered following penetrating combat brain trauma.^3,28,29

• The kinematics of combat trauma can be very different from that seen in the civilian setting. The muzzle velocities of military rifles are much higher than civilian hand guns which may lead to cavitation and surrounding devitalized tissue. Additionally, blasts can create four to five different classes of injury to the brain and other organ systems complicating management.³⁰
  • Primary Blast Injury — Blast overpressure from pressure waves.
  • Secondary Blast Injury — Penetrating fragmentation injuries.
  • Tertiary Blast Injury — Displacement of the casualty or debris that falls on the casualty from the blast.
  • Quaternary Blast Injury — Injury from the thermal effect or release of toxins from the blast.
  • Quinary Blast Injury — Hyperinflammatory state after blast trauma.
• Patients will require aeromedical evacuation within and out of theater. During transportation, significant intervention for intracranial hypertension is limited. Consider pre-transport decompressive techniques and Enroute monitoring devices to address these operational needs.

NOTE: Craniectomy also facilitates early Critical Care Air Transport Team (CCATT) transport of patients out of theater.

Skull Flap Management

For US and Coalition forces:

1. Those who have penetrating brain trauma: Do not save or send the calvarium as alloplastic reconstruction techniques are used for these casualties.
2. Those who have blunt trauma: Consider abdominal subcutaneous implantation of the calvarial flap for later reconstruction if it can be done in a sterile fashion.

For Host Nationals:

1. Clean and replace.
2. Clean and replace with hinge craniectomy. This involves partial fixation of the superior aspect of the bone flap, allowing it to “hinge” outward to accommodate swelling.³¹
3. Craniectomy with potentially limited chances for cranioplasty in the future, depending on local rules of eligibility.

ICP Monitoring and Surgical Intervention

ICP monitoring and/or surgical intervention is not advised for those patients with a GCS 3-5 and evidence of CT scan findings and history suggestive of diffuse anoxic injury if long term continuing care and rehabilitative capabilities are not available in the nation of origin.

Performance Improvement Monitoring

Population of Interest

1. All patients with a diagnosis of traumatic brain injury and an initial GCS of 3-8.
2. All patients who receive a cranial procedure (ICP monitor, craniectomy, craniotomy).

Intent (Expected Outcomes)

1. All patients in population of interest avoid hypotension and hypoxia: SBP never < 100 mmHg, MAP never < 60, SaO₂ never < 93%.
2. All patients in population of interest have PaCO₂ monitored at every role of care.
3. All patients in population of interest have a head CT performed within 4 hours of injury.
4. All patients with a ventriculostomy have hourly documentation of ICP/CPP and ventriculostomy output.
5. Patients in population of interest unable to be monitored clinically (e.g., unable to hold sedation for Q1 hour neuro exam) have an ICP monitor or ventriculostomy placed prior to transport out of theater.

Performance/Adherence Metrics

1. Number and percentage of patients in the population of interest with lowest SBP<100 within first 3 days after injury.
2. Number and percentage of patients in the population of interest with MAP<60 within first 3 days after injury.
3. Number and percentage of patients in the population of interest with SaO₂<93% within first 3 days after injury.
4. Number and percentage of patients in population of interest who have PaCO₂ documented at every role of care (POI, POI MEDEVAC, ROLE 2-4, interfacility MEDEVAC).
5. Number and percentage of patients in the population of interest who maintain PaCO₂=35-40
6. Number and percentage of patients who had a head CT performed within 4 hours of injury.
7. Number and percentage of patients with a ventriculostomy who had hourly documentation of ICP/CPP and ventriculostomy output.
8. Number and percentage of patients in the population of interest unable to be monitored clinically (eg. unable to hold sedation for Q1 hour neuro exam) who have an ICP monitor or ventriculostomy placed prior to transport out of theater.

Data Source

• Patient Record
• Department of Defense Trauma Registry (DoDTR)
• ICU flow sheet
• Neurologic assessment flow sheet

System Reporting & Frequency

The above constitutes the minimum criteria for PI monitoring of this CPG. System reporting will be performed annually; additional PI monitoring and system reporting may be performed as needed.

The system review and data analysis will be performed by the Joint Trauma System (JTS) Director and the JTS Performance Improvement Branch.

Responsibilities

It is the trauma team leader’s responsibility to ensure familiarity, appropriate compliance and PI monitoring at the local level with this CPG.

Appendix A: General Indications

* Individualized patient management in consultation with Neurosurgeon

Appendix B: 3% Saline Protocol

Hypertonic (3% saline) may be delivered via peripheral IV or intraosseous access.

1. Give 250cc 3% NaCl bolus IV (children 5 cc/kg) over 10–15 minutes.
2. Follow bolus with infusion of 3% NaCl at 50 cc/hour.
3. If awaiting transport; check serum Na+ levels every hour:
• If Na < 150 mEq/L re-bolus 150 cc over 1 hour then resume previous rate
• If Na 150–154, increase NaCl infusion 10 cc/hour
• If Na 155–160, continue infusion at current rate
• If Na >160, hold infusion, recheck in 1 hour
4. Once Na is within the range- continue to follow the serum Na+ level every 6 hours
5. After cessation of 3% NaCl infusion, continue to monitor serum Na for 48 hours to monitor for rebound hyponatremia.

Appendix C: Additional Information Regarding off-label Uses in CPGS

Purpose

The purpose of this Appendix is to ensure an understanding of DoD policy and practice regarding inclusion in CPGs of “off-label” uses of U.S. Food and Drug Administration (FDA)–approved products. This applies to off-label uses with patients who are armed forces members.

Background

Unapproved (i.e. “off-label”) uses of FDA-approved products are extremely common in American medicine and are usually not subject to any special regulations. However, under Federal law, in some circumstances, unapproved uses of approved drugs are subject to FDA regulations governing “investigational new drugs.” These circumstances include such uses as part of clinical trials, and in the military context, command required, unapproved uses. Some command requested unapproved uses may also be subject to special regulations.

Additional Information Regarding off-label Uses in CPGS

The inclusion in CPGs of off-label uses is not a clinical trial, nor is it a command request or requirement. Further, it does not imply that the Military Health System requires that use by DoD health care practitioners or considers it to be the “standard of care.” Rather, the inclusion in CPGs of off-label uses is to inform the clinical judgment of the responsible health care practitioner by providing information regarding potential risks and benefits of treatment alternatives. The decision is for the clinical judgment of the responsible health care practitioner within the practitioner-patient relationship.

Additional Procedures

Balanced Discussion

Consistent with this purpose, CPG discussions of off-label uses specifically state that they are uses not approved by the FDA. Further, such discussions are balanced in the presentation of appropriate clinical study data, including any such data that suggest caution in the use of the product and specifically including any FDA-issued warnings.

Quality Assurance Monitoring

With respect to such off-label uses, DoD procedure is to maintain a regular system of quality assurance monitoring of outcomes and known potential adverse events. For this reason, the importance of accurate clinical records is underscored.

Information to Patients

Good clinical practice includes the provision of appropriate information to patients. Each CPG discussing an unusual off-label use will address the issue of information to patients. When practicable, consideration will be given to including in an appendix an appropriate information sheet for distribution to patients, whether before or after use of the product. Information to patients should address in plain language: a) that the use is not approved by the FDA; b) the reasons why a DoD health care practitioner would decide to use the product for this purpose; and c) the potential risks associated with such use.