Variability in Serum Sodium Concentration and Prognostic Significance in Severe Traumatic Brain Injury: A Multicenter Observational Study

Effect of continuous hypertonic saline infusion on clinical outcomes in patients with traumatic brain injury

Osmotic therapy has been recognized as an important treatment option for patients with traumatic brain injury (TBI). Nevertheless, the effect of hypertonic saline (HTS) remains unknown, as findings are primarily based on a large database. This study aimed to elucidate the effect of HTS on the clinical outcomes of patients with TBI admitted to the intensive care unit (ICU). We retrospectively identified patients with moderate-to-severe TBI from two public databases: Medical Information Mart for Intensive Care (MIMIC)-IV and eICU Collaborative Research Database (eICU-CRD). A marginal structural Cox model (MSCM) was used, with time-dependent variates designed to reflect exposure over time during ICU stay. Trajectory modeling based on the intracranial pressure evolution pattern allowed for the identification of subgroups. Overall, 130 (6.65%) of 1955 eligible patients underwent HTS. MSCM indicated that the HTS significantly associated with higher infection complications (e.g., urinary tract infection (HR 1.88, 95% CI 1.26-2.81, p = 0.002)) and increased ICU LOS (HR 2.02, 95% CI 1.71-2.40, p < 0.001). A protective effect of HTS on GCS was found in subgroups with medium and low intracranial pressure. Our study revealed no significant difference in mortality between patients who underwent HTS and those who did not. Increased occurrence rates of infection and electrolyte imbalance are inevitable outcomes of continuous HTS infusion. Although the study suggests slight beneficial effects, including better neurological outcomes, these results warrant further validation.

Clinical descriptors of disease trajectories in patients with traumatic brain injury in the intensive care unit (CENTER-TBI): a multicentre observational cohort study

BACKGROUND

Patients with traumatic brain injury are a heterogeneous population, and the most severely injured individuals are often treated in an intensive care unit (ICU). The primary injury at impact, and the harmful secondary events that can occur during the first week of the ICU stay, will affect outcome in this vulnerable group of patients. We aimed to identify clinical variables that might distinguish disease trajectories among patients with traumatic brain injury admitted to the ICU.

METHODS

We used data from the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) prospective observational cohort study. We included patients aged 18 years or older with traumatic brain injury who were admitted to the ICU at one of the 65 CENTER-TBI participating centres, which range from large academic hospitals to small rural hospitals. For every patient, we obtained pre-injury data and injury features, clinical characteristics on admission, demographics, physiological parameters, laboratory features, brain biomarkers (ubiquitin carboxy-terminal hydrolase L1 [UCH-L1], S100 calcium-binding protein B [S100B], tau, neurofilament light [NFL], glial fibrillary acidic protein [GFAP], and neuron-specific enolase [NSE]), and information about intracranial pressure lowering treatments during the first 7 days of ICU stay. To identify clinical variables that might distinguish disease trajectories, we applied a novel clustering method to these data, which was based on a mixture of probabilistic graph models with a Markov chain extension. The relation of clusters to the extended Glasgow Outcome Scale (GOS-E) was investigated.

FINDINGS

Between Dec 19, 2014, and Dec 17, 2017, 4509 patients with traumatic brain injury were recruited into the CENTER-TBI core dataset, of whom 1728 were eligible for this analysis. Glucose variation (defined as the difference between daily maximum and minimum glucose concentrations) and brain biomarkers (S100B, NSE, NFL, tau, UCH-L1, and GFAP) were consistently found to be the main clinical descriptors of disease trajectories (ie, the leading variables contributing to the distinguishing clusters) in patients with traumatic brain injury in the ICU. The disease trajectory cluster to which a patient was assigned in a model was analysed as a predictor together with variables from the IMPACT model, and prediction of both mortality and unfavourable outcome (dichotomised GOS-E ≤4) was improved.

INTERPRETATION

First-day ICU admission data are not the only clinical descriptors of disease trajectories in patients with traumatic brain injury. By analysing temporal variables in our study, variation of glucose was identified as the most important clinical descriptor that might distinguish disease trajectories in the ICU, which should direct further research. Biomarkers of brain injury (S100B, NSE, NFL, tau, UCH-L1, and GFAP) were also top clinical descriptors over time, suggesting they might be important in future clinical practice.

FUNDING

European Union 7th Framework program, Hannelore Kohl Stiftung, OneMind, Integra LifeSciences Corporation, and NeuroTrauma Sciences.

Identification of Demographic and Clinical Prognostic Factors in Traumatic Intraventricular Hemorrhage

BACKGROUND

The presence of traumatic intraventricular hemorrhage (tIVH) following traumatic brain injury (TBI) is associated with worse neurological outcome. The mechanisms by which patients with tIVH have worse outcome are not fully understood and research is ongoing, but foundational studies that explore prognostic factors within tIVH populations are also lacking. This study aimed to further identify and characterize demographic and clinical variables within a subset of patients with TBI and tIVH that may be implicated in tIVH outcome.

METHODS

In this observational study, we reviewed a large prospective TBI database to determine variables present on admission that predicted neurological outcome 6 months after injury. A review of 7,129 patients revealed 211 patients with tIVH on admission and 6-month outcome data. Hypothesized risk factors were tested in univariate analyses with significant variables (p < 0.05) included in logistic and linear regression models. Following the addition of either the Rotterdam computed tomography or Glasgow Coma Scale (GCS) score, we employed a backward selection process to determine significant variables in each multivariate model.

RESULTS

Our study found that that hypotension (odds ratio [OR] = 0.35, 95% confidence interval [CI] = 0.13-0.94, p = 0.04) and the hemoglobin level (OR = 1.33, 95% CI = 1.09-1.63, p = 0.006) were significant predictors in the Rotterdam model, whereas only the hemoglobin level (OR = 1.29, 95% CI = 1.06-1.56, p = 0.01) was a significant predictor in the GCS model.

CONCLUSIONS

This study represents one of the largest investigations into prognostic factors for patients with tIVH and demonstrates that admission hemoglobin level and hypotension are associated with outcomes in this patient population. These findings add value to established prognostic scales, could inform future predictive modeling studies, and may provide potential direction in early medical management of patients with tIVH.

Trauma-related electrolyte disturbances: From resuscitation to rhabdomyolysis

Traumatic injury results in drastic changes to a patient's normal physiology. The hormonal stress response, as well as some treatment strategies, lead to significant disruptions in electrolyte homeostasis that are important for clinicians to understand. In addition, advances in fluid resuscitation and modern transfusion practices have led to their own unique set of consequences, which we are just beginning to appreciate. Special attention is placed on rhabdomyolysis, as this distinct entity represents an extreme example of injury induced electrolyte derangements. This review describes the physiologic response to trauma and highlights some of the important electrolyte abnormalities that can be encountered while caring for the injured patient.