Epidemiological and clinical characteristics predictive of ICU mortality of patients with traumatic brain injury treated at a trauma referral hospital - a cohort study

BACKGROUND

Traumatic brain injury (TBI) has substantial physical, psychological, social and economic impacts, with high rates of morbidity and mortality. Considering its high incidence, the aim of this study was to identify epidemiological and clinical characteristics that predict mortality in patients hospitalized for TBI in intensive care units (ICUs).

METHODS

A retrospective cohort study was carried out with patients over 18 years old with TBI admitted to an ICU of a Brazilian trauma referral hospital between January 2012 and August 2019. TBI was compared with other traumas in terms of clinical characteristics of ICU admission and outcome. Univariate and multivariate analyses were used to estimate the odds ratio for mortality.

RESULTS

Of the 4816 patients included, 1114 had TBI, with a predominance of males (85.1%). Compared with patients with other traumas, patients with TBI had a lower mean age (45.3 ± 19.1 versus 57.1 ± 24.1 years, p < 0.001), higher median APACHE II (19 versus 15, p < 0.001) and SOFA (6 versus 3, p < 0.001) scores, lower median Glasgow Coma Scale (GCS) score (10 versus 15, p < 0.001), higher median length of stay (7 days versus 4 days, p < 0.001) and higher mortality (27.6% versus 13.3%, p < 0.001). In the multivariate analysis, the predictors of mortality were older age (OR: 1.008 [1.002-1.015], p = 0.016), higher APACHE II score (OR: 1.180 [1.155-1.204], p < 0.001), lower GCS score for the first 24 h (OR: 0.730 [0.700-0.760], p < 0.001), greater number of brain injuries and presence of associated chest trauma (OR: 1.727 [1.192-2.501], p < 0.001).

CONCLUSION

Patients admitted to the ICU for TBI were younger and had worse prognostic scores, longer hospital stays and higher mortality than those admitted to the ICU for other traumas. The independent predictors of mortality were older age, high APACHE II score, low GCS score, number of brain injuries and association with chest trauma.

Analysis of TGF-beta 1 gene expression in contused rat spinal cord using quantitative RT-PCR

We have used northern blot analysis and quantitative reverse transcription polymerase chain reaction (RT-PCR) to determine the postinjury expression profile of the transforming growth factor-beta 1 (TGF-beta 1) gene in the contused rat spinal cord. Spectrophotometric estimates of total sample RNA and quantitative analyses of cyclophilin mRNA using RT-PCR served as controls for comparisons between samples. No changes in cyclophilin gene expression were found at any postinjury survival times. The results of the TGF-beta 1 analyses, which were carried out on spinal cord samples taken at postinjury intervals ranging from 6 h to 10 days, show that the amount of TGF-beta 1 mRNA present in spinal cord increases rapidly following injury, reaching maximum levels 7 days postinjury. Unoperated control samples contained approximately 2 x 10(8) molecules of TGF-beta 1 mRNA/0.5 microgram total RNA. By 1 day postinjury, the amount of TGF-beta 1 mRNA in the cord had increased by a factor of 2.5 to 5 x 10(8) molecules/0.5 microgram total RNA. At 7 days postinjury, there were approximately 15 x 10(8) molecules of TGF-beta 1 mRNA/0.5 microgram total RNA. By 10 days postinjury the amount of TGF-beta 1 mRNA present in the spinal cord had declined to 8 x 10(8) molecules of TGF-beta 1 mRNA/0.5 microgram total RNA, a value similar to that observed at 3 days postinjury. The roles that TGF-beta 1 might play in modifying cellular responses in injured spinal cord are discussed.