|Year : 2017 | Volume
| Issue : 4 | Page : 207-211
Factors influencing outcome in head injury patients with glasgow coma scale <8
Kodeeswaran Marappan1, M Prabhu2, Balasubramani K2, Sherina Paul Raj3
1 Department of Neurosurgery, Apollo First Med Hospital; Department of Neurosurgery, Kilpauk Medical College and Hospital, Chennai, Tamil Nadu, India
2 Institute of Neurosurgery, Madras Medical College and Hospital, Chennai, Tamil Nadu, India
3 Department of Neurosurgery, Apollo First Med Hospital, Chennai, Tamil Nadu, India
|Date of Web Publication||5-Feb-2018|
No 3, Nanda Nikethan, 10, Valliammal Street, Kilpauk, Chennai - 600 010, Tamil Nadu
Source of Support: None, Conflict of Interest: None
Background: Over the years in the emergency department, it has been generally observed that the overall outcome in severe head injury patients is very poor. Hence, a study was conducted in traumatic brain injury patients with a Glasgow Coma Scale (GCS) <8, in which various factors that affect outcome in severe head injury patients were analyzed. Objective: The objective of the study was to understand the various factors influencing outcome in patients with severe head injury (GCS ≤8). Subjects and Methods: This was a prospective study, conducted on 350 consecutive acute severe head injury patients with a GCS ≤8. Thirteen independent factors expected to affect prognosis of severe head injury patients were analyzed and studied. Multivariate analysis was used to include adjustment for prognostic variables. Positive predictive value and strong association of the data were analyzed using cumulative percentage, Chi-square test, and cross-tabulation. Results: From the study, it was observed that male population, older age group patients, low GCS on arrival, train accidents, increased time interval, poor motor response, sluggish or absent pupillary reaction to light, absence of dolls eye movement, presence of comorbidities and other severe traumatic injury of major organs, poor glycemic status, and altered coagulation profile were associated with poor outcome in patients. Conclusions: A keen evaluation of patient profile before taking definitive management decisions is recommended, so as to improve the outcome in severe head injury patients. This is because, there are certain factors such as glycemic statuses of the patient, hemoglobin level, and coagulation profile that are modifiable, and if identified and corrected early, could improve the prognosis of the patients to a large extent.
Keywords: Head injury patients, outcome, severe head injury, traumatic brain injury
|How to cite this article:|
Marappan K, Prabhu M, Balasubramani, Raj SP. Factors influencing outcome in head injury patients with glasgow coma scale <8. Apollo Med 2017;14:207-11
| Introduction|| |
Head injury is a collective term and includes injury to the scalp and face. Head injury can be present with or without underlying brain trauma. Brain trauma resulting from head injury is called traumatic brain injury (TBI). TBI is one of the most important public health concerns worldwide. The incidence of TBI is increasing sharply worldwide, mainly due to the reckless driving practices, which contribute to the increasing number of motor vehicle accidents (MVAs).
Brain damage results from external forces. The nature, intensity, direction, and duration of these forces determine the pattern and extent of damage. The extent of brain damage, associated with various other modifiable and nonmodifiable factors contribute to the outcome of the patient's condition. The extent of brain injury sustained by the patient can be assessed using the Glasgow Coma Scale (GCS) and the outcome of these patients assessed using the Glasgow Outcome Scale (GOS). According to Jannett and Plum, the GOS comprises four outcome categories:,,
- Vegetative state – In vegetative state, patients breathe spontaneously and have periods of spontaneous eye opening, show reflex response in their limbs to painful stimuli, and they may swallow food placed in their mouths. However, they show no evidence of meaningful responsiveness
- Severe disability – This indicates that a patient is conscious but needs the assistance of another person for some activities of everyday living. These patients may be referred to as “conscious but dependent”
- Moderate disability – These patients are “independent but disabled.” However, some previous activities, either at work or in social life, are now no longer possible due to either physical or mental deficit
- Good recovery – Patient has a good recovery and can resume normal activities, although there may be minimal physical or mental deficits.
In severe head injury patients, factors such as age of the patient, sex, mode of injury, time interval (from the time of injury to when the patient was received in the emergency department [ED]), initial GCS, pupillary size and symmetry and pupillary reaction to light, to a very large extent contribute to the outcome of these patients.,,,,, Knowing which factor has a most and least impact on the outcome helps physicians not only with the management decisions but also enables one to give the right advice to the patient and his family. Our study focuses on TBI patients with a GCS <8, in whom, various factors that affect the outcome in severe head injury patients were analyzed, and the extent to which these factors affect patient's outcome was also studied.
| Subjects and Methods|| |
In a prospective study conducted on 350 consecutive acute severe head injury patients with a GCS ≤8, 13 independent factors were analyzed, and the extent to which these factors affected outcome of the patients was also studied. These factors include (1) mode of injury, (2) time interval (time between the injury and hospital admission, (3) age, (4) sex, (5) GCS score on admission, (6) motor response, (7) pupils, (8) Dolls eye movement (DEM), (9) associated injuries, (10) computed tomography (CT) findings, (11) glycemic status, (12) hemoglobin level, and (13) coagulation profile. The factors were analyzed with the GOS, and multivariate analysis was used to include adjustment for the prognostic variables. Positive predictive value and strong association of the data were also analyzed using cumulative percentage, Chi-square test, and cross-tabulation.
All adult head injury patients with GCS 9 and above, all pediatric patients with age 14 and below, and patients treated outside (private hospitals) were excluded from the study.
| Results|| |
Based on the study on 350 patients, overall outcome of the severe head injury patients has been summarized in [Table 1]. Majority of the patients with severe head injury died (48.6%), followed by 19.4% people with severe disability and 6% of the patients who went into a vegetative state. Good recovery was seen in only 12% of the patients while 14% had a moderate recovery.
|Table 1: Overall outcome of the severe head injury patients in our study|
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It was noted that:
- Train accidents, although less common compared to road traffic accidents, pose a higher threat to life
- Patients reporting within 2 h of trauma had a good outcome. The death percentage increased as the time interval of arrival increases
- Lower the GCS of the patient on arrival, lesser was his/her survival rate
- Patients who presented with asymmetric or nonreactive pupils had a poor outcome
- Impaired DEM in patients meant poor outcome or death
- When GCS was checked, patients with a good motor response could survive better than the patients who had no or poor motor response. Hence, it was also concluded that among the three parameters of GCS, motor response assessment was a good predictor of outcome
- When head injury was associated with other injuries, outcome was very poor
- Anemia plays an important role as it causes more death when present along with severe head injury. Good recovery was seen in patients with normal hemoglobin status
- Comorbid conditions when present in patients with severe head injury were associated with a more number of deaths compared to normal patients
- A coagulation disturbance in head injury patient was directly proportionate to increased number of death
- Patients tend to recover well when treated surgically, compared to those who were conservatively managed.
| Discussion|| |
There are many factors that significantly affect the outcome in severely head-injured patients. Although a patient is treated surgically or conservatively, ultimately, the outcome is the most significant part of the treatment. It is thereby important to know the factors that contribute to a better or worse outcome. This knowledge helps physicians make the right move, in the management of every head injury patient brought to the emergency department. The overall outcome of severe head injury patients can be assessed using the GOS, which comprises five individual factors: (1) death, (2) persistent vegetative state, (3) severe disability, (4) moderate disability, and (5) good recovery.,,
Patients with a GCS of 8 or less are those patients who are said to have sustained severe head injury. These patients predominantly face death or go into a persistent vegetative state. However, it is important to know what are the factors contributing to this outcome in patients and which factor has the major impact in the prognostication of patients. Based on various other studies,,,,,,, 13 factors have been known to contribute to the outcome of head injury patients.
According to traumatic coma data bank study, reaction of the aged brain to trauma may be apparently severe when compared to young patients' brain. This has proved to be true in this study comprising 350 severe head injury patients, majority of whom were in the third decade, followed by fourth and second decade patients. When comparing the outcome of patients under each age group, good recovery was seen in patients in the second decade, followed by third and fourth decade patients. Death was imminent among the elderly patients. Hence, age is a strong factor that influences both mortality and morbidity.
Males are usually the breadwinners of the family. This calls for daily travel through the public or private means of transport. Hence, be it road traffic accidents, train accidents, fall from work site, or assault, majority of the victims tend to be males. In this study of 350 severe head injury patients, the female head injury contributes only a meager amount and the male: female ratio was 10:1.
Mode of injury
MVAs were the most common mode of head injury than any other. Among 350 severe head injury patients who were studied, 272 (77.7%) patients had sustained severe head injury secondary to MVAs. Hence both death and good recovery were more among MVA victims. However, in comparison with the other three modes of injury, i.e. train accidents, assault and falls, outcome was very poor among train accident victims, were 73.1% of the cases died. Among the fall and assault injuries, the outcome was comparatively better. This shows that train accidents are more fatal when compared to other modes of head injury.
Time interval refers to the hours in between the time of injury to the time when patient was brought to the hospital. It is very important that severe head injury patients reach the hospital on time., Every single minute is very important to their life. Time delay causes a further deterioration in GCS. Majority (48.6%) of patients in the study were brought to the hospital in 4–8 h. Nearly 22.9% patients were brought in 2–4 h and 14.6% patients in <2 h. Best outcome was seen in patients brought to the hospital in <2 h. The outcome declined as the time interval increased. Death rate gradually increases from 73.2% to 85.7% and reached 100% as the time interval increases to >24 h.
Glasgow Coma Scale
The GCS is an objective measurement of level of consciousness. As seen in a study conducted by Narayan et al., the GCS score alone was accurate in 80% of outcome predictions but at a lower level of confidence (25% at the over – 90% level). Our study showed that 65% of patients with GCS 3 on admission died, followed by GCS 4, 5. and 6. Hence, it was seen that poor GCS contributed to poor outcome, i.e., death. GCS 7 and 8 patients could survive the trauma. Using statistical analysis, the P value for GCS score on admission was significant (P ≤ 0.001).
Pupillary size and reaction to light
The parasympathetic, pupilloconstrictor, light reflex pathway mediated by the third cranial nerve is anatomically adjacent to brainstem areas controlling consciousness and the medial temporal lobe. Therefore, damage to the midbrain third nucleus or efferent third nerve by temporal lobe compression produced dilation of pupils. If the damage or compression is significant, the pupils will be fixed to light reflex. This pupillary light reflex and size of the pupil have traditionally been used as a clinical parameter in assessing transtentorial herniation as a prognostic factor, and therefore these serve as an indirect measurement of dysfunction to pathways subserving consciousness and thus an important clinical parameter in assessing outcome from traumatic coma. In our study of 350 patients, 273 patients (78%) had symmetric pupils. These patients ultimately had a good recovery. Patients with asymmetric pupils had a poor outcome in the form of death (73 patients), persistent vegetative state (2 patients), and severe disability (2 patients). The fact that asymmetric pupils contribute to poor outcome was proved statistically.
Similarly, among the 350 patients, in 132 patients, pupils were reactive to light. Among these patients, 39 patients had a good outcome and 8 patients died. However, a total of 218 patients had single or double pupils nonreactive to light. In these, 162 patients died and only 3 patients had a good recovery. Hence, pupils not reactive to light indicated poor outcome (162 deaths in the study population, with a significant P value).
Doll's eye movement
Among 350 severe head injury patients, DEM was present in 138 patients among whom 40 (95.2%) patients had a good recovery. However, in 57 patients, DEM was absent and all of them died. DEM thus exactly predicts the brain stem function. An absent as well as impaired DEM in severely injured patients resulted in death. More than 50% of the study population died, with a statistically significant P value. Thus, DEM is an important factor in assessing outcome of severely head-injured patients. It is recommended that this test is carried out at the bedside of all head injured patients, upon arrival at the emergency unit.
In the GCS scoring system, motor response is the subscore of GCS score. It is a better predictor of outcome than the verbal and eye-opening components. Motor response is graded from 1 to 6 as below:
- No response
- Decerebrate posture
- Decorticate posture
- Flexion to pain
- Localizing pain
- Obeying all commands.
Among 350 severe head injury patients, motor response M-1 had a very poor outcome. The patients with M-1 had 100% mortality. Best outcome was seen in patients with M-5. Among 94 patients, 33 (78.6%) patients had a good recovery. The outcome was worse as the motor response decreased. Hence, assessing motor response helps physicians prognosticate patient's condition more accurately.
Computed tomography findings
A CT scan is routinely performed in all patients with severe TBI and provides information with important therapeutic implications for operative or nonoperative intervention., As reported in previous studies, individual CT characteristics found to be particularly relevant in terms of prognosis were:
- Association with subdural hematoma ,
- Compression of basal cisterns ,
- Diffuse axonal injury.
Usual CT findings noted in our study were as mentioned in [Table 2]. Predominant parenchymal injuries sustained by severe head injury patients were contusions and subdural hematomas. Other CT findings were almost equal in number, except CT findings of intracranial hemorrhage, which was seen in a minority of patients.
|Table 2: Usual computed tomography scan findings in patients with severe head injury|
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Among 350 severe head injury patients, 79 patients had also sustained injury in other parts of the body. Of the 79 patients, only 5 patients had good recovery whereas the majority of patients (58 patients) died. It was also noted that five patients who recovered well had only sustained bony injuries and not major injuries such as chest and abdomen trauma. The observation thus proved that presence of other major traumatic injuries, in any other part of the body, along with severe head injury, contributed to poor outcome among patients.
In the study comprising 350 severe head injury patients, 78 patients were anemic. Among the anemic patents, 58 died, hence proving that severe head injury patients with anemia (low hemoglobin level) had increased mortality rate. This shows the importance of checking the hemoglobin status of severe head injury patients, upon admission. Hemoglobin status is a modifiable risk factor. Hence, appropriate measures taken at the earliest to improve hemoglobin levels can prevent mortality rate to a large extent.
It was also noted that the presence of comorbid conditions in patients with severe head injury influenced the outcome of patients to a large extent. In the study, 39 patients had a history of other comorbid conditions such as diabetes/hypertension. Among the 39 patients, only three patients had a good recovery. Hence, the presence of comorbidities resulted in a poorer outcome.
In the study of 350 severe head injury patients, 33 patients had an abnormal coagulation profile. All these patients sustained multiple intraparenchymal contusion, as observed in CT scan of the brain. Of the 33 patients, two patients underwent surgery after correction of the coagulation abnormality. The two treated patients had a good recovery. Rest of the 29 patients were treated conservatively treated in view of the coagulation abnormality and thus resulted in poor outcome (death). Hence, an abnormal coagulation profile contributed to a poor outcome among patients, if not treated early.
Among 350 severe head injury patients, majority of the patients (199 patients) were treated surgically. However, 151 patients were conservatively managed. Good recovery was seen among 71.4% of the patients who were surgically treated. On the other hand, death rate was high among the patients treated conservatively. Those who survived among them had a very poor outcome. The observation showed that early surgical management of severe head injury patients helps improve the prognosis.
| Conclusions|| |
The above observations show the importance of these factors in determining the outcome and prognosis of patient's sustaining severe brain injury. Hence, good history taking, complete physical examination, and detailed evaluation of patient's condition, followed by an initial CT scan are important in the evaluation of severe head injury patients brought to the emergency unit. A quick bedside initial assessment of the patients for DEM, pupillary response, motor assessment, and GCS scoring would help physicians accurately prognosticate patient's condition and outcome. In addition, the clinical evaluation of the patient, his or her hemoglobin status, hematological status, presence or absence of comorbid conditions, and presence of other injuries are also to be evaluated and elicited, as these factors if assessed and treated early can modify the outcome of patients. In this way, outcome of severe head injury patients can be improved and in turn the number of head injury-related deaths in the neurosurgery department can be reduced.
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Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]