1. Data are insufficient to support a treatment standard for Glasgow Coma Scale (GCS) scoring and pupil assessment in patients with severe traumatic brain injury (TBI) incurred in combat.
2. Measuring GCS score and assessing pupils:
   1. How to measure:
      The GCS score and pupil assessment should be determined by direct clinical examination.
   2. Who should measure:
      1. The far forward first medical provider (medic) should obtain the first score. At each echelon of care, the primary medical care provider should be responsible for measuring the GCS and assessing the pupils.
      2. Competence in measuring the GCS and assessing the pupils should be maintained.
   3. When to measure:
      1. The GCS and pupils should be measured as soon as tactically possible.
      2. At regular intervals, the GCS and pupils should be reassessed, in addition to measuring GCS before transport to the next echelon of care and after arrival at the higher echelon.
3. For acute pupillary dilation, brain herniation should be considered and appropriate intervention instituted (see Treatment section). However, patients exposed to chemical agents or explosive blast may experience iridoplegia, which is not indicative of herniation.

The Glasgow Coma Score was developed by Teasdale and Jennett1 in 1974 as a means by which to quantitatively describe the level of consciousness of patients who had suffered TBI. Since then, it has gained wide civilian use and is applied most appropriately as a measure of severity of TBI. While the GCS directly measures the depth of coma through a battery of metrics, practitioners are able to use depth of coma as a proxy for severity of injury.2 The GCS is an inexpensive highly reliable method of recording and reporting the neurologic state of TBI patients. In the civilian sector, a wide variety of health care providers are trained to perform this test.

Clinical examination of pupils is an important aspect of neurologic assessment. Pupil assessment is defined as each pupil's size at baseline and each pupil's response to direct light stimulation. It can be performed easily and quickly, and results are objective. Asymmetry between the sizes of the two pupils in the same patient can be indicative of severe brain dysfunction.3 Among patients suffering from TBI, pupil dilation and paralysis of pupillary constriction when stimulated by light is associated with poor clinical outcome.4,5 Further, in the acute clinical setting, these can also be indicative of brain herniation.3

The GCS score and pupillary exam is taught to every military medical care provider. It is part of the core curriculum for 91W advanced medics. It is also part of the Advanced Trauma Life Support (ATLS) course of the American College of Surgeons.6 ATLS certification is a requirement of all military physicians, regardless of specialty. Although each medical officer is not required to maintain ATLS certification, they must have taken and passed the course at least once in their career.

The retention of the GCS among military physicians is poor.7 The retention among combat medics in the field is unknown. However, one can assume that without regular refresher courses, retention will also be poor.

The usefulness of a quantitative clinically relevant measure of head injury severity, such as the GCS, cannot be understated. In the setting of head injury, using simple methods, such as examination of the pupils, to make early diagnosis of brain dysfunction and herniation can be lifesaving. Military medical providers have to make triage decisions. Triage is perhaps the most important function a medic on the battlefield can perform. Triage is the basis of who gets medical care, who gets evacuated, with what priority and by what means. Unlike the civilian sector, the sickest patients do not typically get priority. A measure of head injury severity like GCS is particularly helpful in enabling the first provider to be able to make these difficult decisions.

Both the GCS and abnormal pupillary function are not intended for and thus do not identify mild TBI, nor are they intended for making a definitive disposition regarding long term outcome. Studies of military patients from Operation Iraqi Freedom and Operation Enduring Freedom suggest that a significant portion of combat casualties may have mild TBI without a history of loss of consciousness or awareness. Numerous troops complain of nausea, vertigo, frequent headache, and loss of appetite and sleep at weeks and months after returning from deployment. Not all of these troops had abnormal GCS scores in theater or several days and weeks post injury.8 A TBI casualty can have a GCS score of 15 and have marked impairment of mental status. GCS is probably most helpful in the acute phase of assessment and intervention, but a more functional score should be utilized for further care and definitive dispositions. Additionally, in a 2005 publication, Davis et al.9 found that GCS values have the limited ability to predict severity of injury and length of stay in the intensive care unit. However, there is a statistically significant correlation between Head AIS and GCS score.

The search engine PubMed was used. The time period was 1980 to 2005. The queries were based on the terms "head injury," "military," "GCS," "pupils" and "pupillary response." Changing the terms to "brain injury," "TBI," "loss of consciousness," and "combat" did not identify any other articles. Queries using "GCS" and "performance" and "first providers" and "military" and "pupils" yielded no articles. Changing the terms to "medic," "retention," and "combat" did not identify any other articles. Review of the bibliography of identified articles also did not identify any other pertinent articles.

Medical care on the modern battlefield remains dangerous and chaotic. The modern combat medic is a highly skilled first provider who works under austere conditions. The ability to conduct meaningful research under these conditions is very difficult, and thus has not been done. The conclusions are extrapolated from the civilian sector and also from studies conducted at higher echelons of care. This too is problematic. Civilian EMT paramedics have significantly more medical training than combat medics. Civilian EMTs have continued refresher training, to which, in theater of war, medics do not have access. Civilian paramedics are able to use more medical resources, some of which have significant implications on the GCS score, such as artificial airways and mechanical ventilation; neither are presently available on the battlefield. For these reasons, the prognosis of a civilian casualty will be better than that of a military patient with the same GCS score.

The mechanisms of military head injury are different than those of civilians. In combat, many military head injury patients suffer penetrating head injury from fragments.10-13 Civilian patients rarely do. Another battle etiology is exposure to explosive blast.14 Although a closed head injury, the similarity of blast-induced neuropathophysiology with civilian closed head injury from blunt impact or acceleration-deceleration, such as from motor vehicle crashes, is unknown. Even gunshot wounds are different in military and civilian patients. Gunshot wounds incurred in battle are typically from high velocity rifle bullets whereas civilian patients usually suffer gunshot wounds from low velocity handgun rounds.12,13,15-18

Basing prehospital conclusions on studies conducted at the hospital is intrinsically flawed. The medical care and resources at a military hospital are vastly superior to what is available to a combat medic in the field. Thus, GCS and pupillary function may not have the same prognostic value.

Military Prehospital GCS Score and Patient Outcome

No studies have been published validating the GCS score in the prehospital far forward combat casualty care setting. Also, there are no military specific studies published that determined the efficacy of the GCS score in determining severity of head injury from the types of head wounds incurred in combat.

Military Prehospital Pupil Assessment and Patient Outcome

No studies have been published validating the pupil assessment in the prehospital far forward combat casualty care setting. Also, there are no published studies that determined the efficacy of pupil assessment in determining or prognosticating severity of head injury from the types of head wounds incurred in combat.

Military Hospital GCS Score and Patient Outcome

GCS score at time of admission to the military surgical hospital is shown to be predictive of severity of head injuries incurred in battle. Aarabi (1990) conducted a retrospective analysis of 435 Iran-Iraq War (1980-88) military patients. GCS score was assigned by the neurosurgeon at the time of admission to the Iranian hospital. There was a positive correlation between GCS and good outcome.19 Of patients who had admission GCS scores of 13-15, 6% died and 52.2% survivors had focal neurological deficits at discharge. This contrasts with patients with admission GCS scores of 3-5, among whom 65% died and 100% of survivors had focal neurological deficits at discharge. Brandvold et al.20 performed a retrospective study of 116 military patients who had suffered TBI during hostile actions in Lebanon from 1982-1985. Of these, 67 were Israeli and 46 could be followed after hospital discharge. GCS score correlated with mortality and clinical outcome. For patients with GCS scores of 3 to 4, 80% died; with GCS scores of 5-12, 12% died; and with GCS scores of 13-15, only 6% died. Using the Glasgow Outcome Scale (GOS), of the patients who presented with GCS scores of 3-4, the few survivors were all Grades III and IV. For those with GCS scores of 5-8, many were Grades III and IV but an increasing number of patients were Grades I and II. If the GCS score was 9-15, almost all patients were Grades I and II.

Admission GCS score on time of arrival at a Yugoslav military hospital is also predictive of survival. Turina et al.21 studied 43 war TBI Yugoslavian military patients. The GCS was higher among survivors as was the War Head Injury Score (WHIS), 11 and 14 respectively. The converse was true for nonsurvivors, in whom the mean GCS score was 4 and WHIS 7.

GCS is shown to be predictive of mortality from traumatic cerebral aneurysm following battle related penetrating brain injury. Aarabi (1995) completed a study of 1306 Iran-Iraq War military patients who had suffered TBI. Of these, 19 had traumatic cerebral aneurysms. Of patients with traumatic cerebral aneurysms and GCS scores of 5-8, 84% died. In contrast, in spite of having aneurysm, those who had GCS scores of 9-15, only 6.6% died.22

However, GCS was not found to be predictive of risk of CNS infection following war-related TBI. Aarabi et al. (1998) published a study of 964 Iran-Iraq War military patients with penetrating brain injuries. GCS was assigned at the time of admission to the Iranian hospital. There was no correlation between GCS and prevalence of CNS infection.23

In a study of debridement of combat-related head wound, the GCS score also was not found to be predictive of outcome in military TBI patients. Amirjamshidi et al.24 reported a study of 99 Iran-Iraq War military patients who had suffered fragment-penetrating brain injuries. GCS was assigned at admission to an Iranian hospital. The primary intention of the study was to study the effect of wound debridement on clinical outcome. Patients ranged in GCS scores from 8-14. Within this range, the GCS score did not correlate with clinical outcome.

Civilian Prehospital GCS Score and Patient Outcome

The reliability and clinical benefit of civilian sector prehospital GCS scoring has been reviewed. The Brain Trauma Foundation's Guidelines for Prehospital Management for Traumatic Brain Injury recommends it for this use.25

Civilian Prehospital Pupil Assessment and Patient Outcome

The reliability and clinical benefit of civilian sector prehospital pupil assessment has been reviewed. Again, the Brain Trauma Foundation's Guidelines for Prehospital Management for Traumatic Brain Injury recommends it for this use.26

GCS Score and Pupil Assessment for Military Patients Suffering from Penetrating Head Injury

To date, there are no published studies validating the use of GCS or pupil assessment for determining the severity of brain injury from U.S. military relevant mechanisms of brain injury, such as fragment or high velocity bullets.

GCS Score and Pupil Assessment for Civilian Patients Suffering from Penetrating Head Injury

The reliability and clinical benefit of GCS scoring and pupil assessment for civilian penetrating head injuries has been reviewed. The Guidelines for Management of Penetrating Head Injuries recommends it for this use.27

Reliability of Prehospital Scoring

The reliability of GCS scoring by U.S. military medical providers is poor. In a prospective study by Riechers et al.7, 90 military physicians were tested on their knowledge of the GCS score. In spite of 87% having had completed ATLS training that included GCS, less than 15% were able to accurately describe each aspect of the score. Poor performance correlated with time since training and with infrequency of GCS use. There is, however, civilian data that show that GCS values have the limited ability to predict severity of injury and length of stay in the intensive care unit. They did find that there is a statistically significant correlation between Head AIS and GCS score.9 The use of reference aids as a means of improving performance was not studied.

Glasgow Coma Scale (GCS) scoring and assessment of pupils should be done in every patient with suspected TBI. The first provider should obtain these measurements as soon as possible, at regular intervals thereafter and before and after transport. Worsening of either should initiate appropriate treatment interventions (see Treatment section).

No Class I evidence is available on which to base conclusions for these parameters. There are very limited numbers of studies conducted on the battlefield of any level on which to determine this. Studies performed in the civilian sector were reviewed in order to evaluate the situation. There are no data from the U.S. military indicating the reliability of the GCS or pupillary response to light as a reliable indicator of the severity of head injury incurred in battle. In the civilian sector, Class II data from civilian victims suffering from traumatic head injury does demonstrate GCS's reliability, particularly with repeated scoring and improvement or deterioration of the score over time. Class II data from civilian patients demonstrate pupil assessment as a useful method for prognosticating poor outcome and as a diagnostic indicator of brain dysfunction, including herniation.

A number of issues require study to evaluate the usefulness of the GCS score and pupillary response to identify and grade military relevant TBI.

1. What is the reliability of the GCS and/or pupil function obtained by combat medics?
2. How well do GCS and/or pupil function correlate with TBI such that these scores have implications for return to duty?
3. Far forward medical providers have limited medical supplies. The decision to commit these supplies to any given patient must be done with the intent to provide maximum benefit to the most patients. Can GCS and/or pupil assessment be used to prognosticate TBI in the military medical care system, particularly as it pertains to committing limited medical resources?
4. Alternative methods of determining severity of TBI have been proposed. These need rigorous evaluation through well-conducted prospective studies. Can GCS and/or pupil function be used as a triage tool under current military medical care guidelines for evacuation to higher levels of care?
5. Are the GCS score and/or pupil function reliable indicators of severity of injury when patients have compromised airways or ventilatory capability but cannot be intubated and mechanically ventilated with supplemental oxygen?
6. Medical care under battlefield conditions generally means how to treat at the minimal acceptable level. This is done in an effort to maximize the number of patients that can be treated for the longest period of time with the fewest available medical resources. Thus for military medical providers, a rational guide to how little therapy an injured patient can tolerate is useful. Can the GCS score be used as a goal of resuscitation under austere limited resource conditions?
7. Should GCS be modified or a new TBI scoring method be developed that is specific for the military combat environment?