A escala de coma de Glasgow como fator decisivo na intubação de pacientes com traumatismo cranioencefálico grave: uma revisão sistemática e meta-análise

Abstract

INTRODUCTION: Traumatic brain injury (TBI) is one of the leading causes of trauma-related death and neurological disability. The Glasgow Coma Scale (GCS) is widely used to classify TBI severity and guide the decision for orotracheal intubation (OTI) in severely injured patients, classically at the threshold of GCS ≤8. However, this practice is controversial and lacks robust supporting evidence. OBJECTIVE: To systematically evaluate the safety of using the Glasgow Coma Scale as a predictor for intubation in patients with severe TBI. METHODS: A systematic review and meta-analysis were conducted following the PRISMA protocol, registered on the PROSPERO platform under number CRD420250652695. The SCOPUS (Elsevier), PUBMED, OpenTheses, Cochrane, MEDLINE, LILACS, and Google Scholar databases were searched from February 22, 2025, to March 20, 2025. Original articles (cohort studies) comparing intubated versus non-intubated adult patients with severe TBI (GCS ≤8) were included, evaluating outcomes such as mortality and length of stay. Methodological quality was assessed using the NIH tool for observational studies. Data synthesis was performed by meta-analysis, using Relative Risk (RR) for mortality and Mean Difference (MD) or Standardized Mean Difference (SMD) for length of stay. RESULTS: Of the 1,495 records identified, 5 cohort studies were included in the review. The main meta-analysis on mortality (n=19,697 patients) demonstrated that intubated patients had a 43% higher risk of mortality compared to non intubated patients (RR=1.43; 95% CI [1.30 – 1.58]; p<0,00001). The result remained robust in the hospital subgroup analysis (RR=1.47; 95% CI [1.32 – 1.63]). Intubated patients also showed a longer hospital length of stay (MD=3.09 days) and ICU length of stay (SMD=0.78), although these findings proved to be fragile and unstable in the sensitivity analysis due to very high heterogeneity (I²=99%). However, after excluding one study with inconsistent data, a robust and significant increase in ICU length of stay (MD=0.92 days; p < 0.00001; I²=11%) was observed in the intubated group. CONCLUSION: This systematic review found no evidence to support the safe use of GCS as an isolated predictor for intubation in patients with severe TBI. The findings suggest an increased risk of mortality in the intubated group, likely associated with confounding by indication, whereby more severely ill patients are preferentially intubated. Therefore, the decision to establish a definitive airway must be individualized, integrating the GCS assessment with other clinical parameters, such as the presence of protective airway reflexes, hemodynamic stability, and pupillary assessment.