Trajectories of early secondary insults correlate to outcomes of traumatic brain injury: results from a large, single centre, observational study

Abstract

Background: Secondary insults (SI), such as hypotension, hypoxia, and intracranial hypertension frequently occur after traumatic brain injury (TBI), and have a strong impact on patients' clinical outcomes. The aim of this study is to examine the trajectories of SI from the early phase of injury in the prehospital setting to hospital admission in a cohort of TBI patients.

Methods: This is a retrospective, observational, single centre study on consecutive patients admitted from 1997 to 2016 to the Neuro Intensive Care Unit (NICU) at San Gerardo Hospital, in Monza, Italy. Trajectories of SI from the prehospital to hospital settings were defined as "sustained", "resolved", "new event", and "none". Univariate and multivariate logistic regression analyses were performed to correlate SI trajectories to a 6-months outcome.

Results: Nine hundred sixty-seven patients were enrolled in the final analysis. About 20% had hypoxic or hypotensive events and 30.7% of patients had pupillary abnormalities. Hypotension and hypoxia were associated with an unfavourable outcome when "sustained" and "resolved", while pupillary abnormalities were associated with a poor outcome when "sustained" and as "new events". After adjusting for confounding factors, 6-month mortality strongly correlated with "sustained" hypotension (OR 11.25, 95% CI, 3.52-35.99), "sustained" pupillary abnormalities (OR 2.8, 95% CI, 1.51-5.2) and "new event" pupillary abnormalities (OR 2.8, 95% CI, 1.16-6.76).

Conclusions: After TBI, sustained hypotension and pupillary abnormalities are important determinants for patients' outcomes. Early trajectories define the dynamics of SI and contribute to a better understanding of how early recognition and treatments in emergency settings could impact on 6-month outcomes and mortality.

Keywords: Outcome; Prehospital insults; Secondary injuries; Trajectory; Traumatic brain injury.

Conflict of interest statement

Ethics approval and consent to participate

Ethical requirements were fulfilled, accordingly to “Decreto Legge 196”, article 4 (2003). Due to the retrospective data analysis and the de-identification of sensible data, no consent was required and no consent was required for data utilization. Ethical Committee and the hospital data protection office approved data utilization and publication.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1

Smooth function of hypoxia, hypotension and pupillary abnormalities at the scene of the accident (panel a) and age at trauma (panel b) in TBI patients admitted during the study period

Fig. 2

Distribution of trajectories of hypoxia, hypotension, and pupillary reactivity in TBI patients admitted to San Gerardo Hospital NICU during the study period

Fig. 3

Differences in oxygenation (SpO2, Box Plot a) and mean arterial pressure (MAP, Box Plot b) across trajectories of hypoxia and hypotension. Box shows the interquartile range and the inner horizontal bold line indicates the median. Whiskers extend the median by ±1.5 times the interquartile range, while dotted points extending beyond the end of the whiskers represents outliers

Fig. 4

Distribution of 6-month outcome measured by GOS (4–5 = Favourable, 1–3 = Unfavourable) in trajectories of hypoxia, hypotension, and pupillary reactivity

Fig. 5

Confidence interval plot of trajectories of hypoxia, hypotension, and pupils in relation to 6-month functional state (a) and 6-month mortality (b). Horizontal lines represent the 95% conficence interval (CI). Odds Ratios (ORs) and 95% CIs were derived from multivariate logistic regression models, adjusted for age, sex, intubation on the scene, sedation on the scene, GCS at the ED, CT classification, presence of SAH, and extracranial lesions