PRESENTING GCS IN ELDERLY PATIENTS WITH ISOLATED TRAUMATIC BRAIN INJURY IS HIGHER THAN IN YOUNGER ADULTS
Authors: Kehoe Anthony D , Smith Jason E , Lecky Fiona , Yates David 
Published: August 2014

Objectives & Background

The relationship between age and presenting Glasgow Coma Scale (GCS) in adults with traumatic brain injury (TBI) has not so far been explored in detail. We have previously reported a trend for higher GCS in elderly patients presenting to our major trauma centre with isolated TBI compared with younger adults. The aim of this study was to confirm and define this relationship using a national trauma registry and to evaluate potential contributory factors.

Table 1

Isolated Head AIS 3+ patients 1988–2014

N
(total 13547)Adults
*mean (95% CI), **median (IQR)N
(total 2485)Elderly
*mean (95% CI), **median (IQR)Male1041076.8% (76.1%–77.6%)136855.1% (53.1%–57.0%)Age**26.1 (15.9–42.0)*77.6 (71.0–84.0)ISS****16 (13–25)**17 (16–25)AIS head****4 (3–5)**4 (4–5)Presenting GCS****14 (9–15)Underwentprocedure*168112.4% (11.9%–13.0%)2008.0% (7.0%–9.1%)30 day mortality*10727.9% (7.5%–8.4%)73229.5% (27.7%–31.2%)Injury mechanismBlast40.0% (0%–0.1%)0Blow186213.7% (13.2%–14.3%)532.1% (1.6%–2.7%)Other166412.3% (11.7%–12.8%)963.9% (3.1%–4.6%)Fall <2 m207315.3% (14.7%–15.9%)124450.1% (48.1%–52.0%)Fall >2 m238217.6% (16.9%–18.2%)52421.1% (19.5%–22.7%)RTC555341.0% (40.2%–41.8%)56722.8% (21.2%–24.5%)Stabbing/shooting90.1% (0%–0.1%)10.0% (0%–0.1%)

Methods

The Trauma Audit Research Network (TARN) database was interrogated to identify all adult (>16 years) cases of isolated TBI (Abbreviated Injury Score (AIS) 3 or greater for head with no AIS >3 in any other system) from 1988 to present. Cases were excluded if evidence of drug or alcohol intoxication, smoke or fume inhalation, psychiatric disturbance or traumatic asphyxia had been recorded. Demographic and detailed injury description data were recorded alongside GCS at Emergency Department presentation. Cases were categorised into adults (16–65 years) and elderly (>65 years). Presenting GCS was compared between the two groups for AIS head 3, 4 and 5. GCS data were not normally distributed therefore differences in GCS between groups were considered using two-way ANOVA performed on rank GCS. Sub-group analyses were performed comparing presenting GCS between adults and elderly in specific mechanisms of injury and for particular types of intracranial injury.

Results

16,032 cases were identified whose baseline characteristics are presented in table 1. Overall, presenting GCS differed significantly between the two groups at each level of AIS severity (figure 1), a finding that was consistently replicated for each common mechanism of injury (all p<0.01) (figure 2). This difference was not limited to any particular type of intracranial injury (figure 3). The inclusion of gender as an additional variable did not change the pattern of the results.

Figure 1

Graph of mean GCS by AIS grade all cases p<0.01.

Figure 2

Graph of mean GCS by AIS grade in most common mechanisms of injury.

Figure 3

Graph of mean GCS by AIS grade in specific intracranial injury types.

Conclusion

We believe that this is the first study to demonstrate that elderly patients present with a higher GCS than younger adults for a given anatomical severity of TBI. This difference is not confined to any particular mechanism of injury nor any type of intracranial injury. These findings may have profound implications for prehospital trauma triage tools, outcome prediction methodologies and neurosurgical decision-making.