Questioning dogma: does a GCS of 8 require intubation?

BACKGROUND: There is no evidence supporting intubation for a Glasgow Coma Scale (GCS) of 8. We investigated the effect of intubation in trauma patients with a GCS 6-8, with the hypothesis that intubation would increase mortality and length of stay.

METHODS: We studied adult patients with GCS 6-8 from the 2016 National Trauma Data Bank. Intubated and non-intubated patients were compared using inverse probability weighted regression adjustment (IPWRA) to control for injury severity and patient characteristics. Outcomes were mortality, intensive care unit length of stay (ICU LOS), and total LOS. Stratified analysis was performed to investigate the effect in patients with and without head injuries.

RESULTS: Among 6676 patients with a GCS between 6 and 84,078 were intubated within 1 h of arrival to the emergency department. The overall mortality rate was 15.1%. IPWRA revealed an increase in mortality associated with intubation (OR 1.05, 95% CI 1.03, 1.06). The results were similar in patients with head injuries (OR 1.04, 95% CI 1.02, 1.06) and without (OR 1.06, 95% CI 1.03, 1.10). Among the 5,742 patients admitted to the ICU, intubation was associated with a 14% increase in ICU LOS (95% CI 8-20%; 5.5 vs. 4.8 days; p < 0.001). The overall length of stay was 27% longer (95% CI 19.8-34.3%) among intubated patients (mean 7.7 vs 6.0 days; p < 0.001).

CONCLUSION: Among patients with GCS of 6 to 8, intubation on arrival was associated with an increase in mortality and with longer ICU and overall length of stay. The use of a strict threshold GCS to mandate intubation should be revisited.