Lund Concept for the Management of Traumatic Brain Injury: A Physiological Principle Awaiting Stronger Evidence

Association of Early Beta-Blocker Exposure and Functional Outcomes in Critically Ill Patients With Moderate to Severe Traumatic Brain Injury: A Transforming Clinical Research and Knowledge in Traumatic Brain Injury Study

OBJECTIVES

We aimed to 1) describe patterns of beta-blocker utilization among critically ill patients following moderate-severe traumatic brain injury (TBI) and 2) examine the association of early beta-blocker exposure with functional and clinical outcomes following injury.

DESIGN

Retrospective cohort study.

SETTING

ICUs at 18 level I, U.S. trauma centers in the Transforming Clinical Research and Knowledge in TBI (TRACK-TBI) study.

PATIENTS

Greater than or equal to 17 years enrolled in the TRACK-TBI study with moderate-severe TBI (Glasgow Coma Scale of <13) were admitted to the ICU after a blunt TBI.

INTERVENTIONS

None.

MEASUREMENTS

Primary exposure was a beta blocker during the first 7 days in the ICU, with a primary outcome of 6-month Glasgow Outcome Scale-Extended (GOSE). Secondary outcomes included: length of hospital stay, in-hospital mortality, 6-month and 12-month mortality, 12-month GOSE score, and 6-month and 12-month measures of disability, well-being, quality of life, and life satisfaction.

MAIN RESULTS

Of the 450 eligible participants, 57 (13%) received early beta blockers (BB+ group). The BB+ group was on average older, more likely to be on a preinjury beta blocker, and more likely to have a history of hypertension. In the BB+ group, 34 participants (60%) received metoprolol only, 19 participants (33%) received propranolol only, 3 participants (5%) received both, and 1 participant (2%) received atenolol only. In multivariable regression, there was no difference in the odds of a higher GOSE score at 6 months between the BB+ group and BB- group (odds ratio = 0.86; 95% CI, 0.48-1.53). There was no association between BB exposure and secondary outcomes.

CONCLUSIONS

About one-sixth of subjects in our study received early beta blockers, and within this group, dose, and timing of beta-blocker administration varied substantially. No significant differences in GOSE score at 6 months were demonstrated, although our ability to draw conclusions is limited by overall low total doses administered compared with prior studies.

Incidence and Clinical Impact of Myocardial Injury Following Traumatic Brain Injury: A Pilot TRACK-TBI Study

BACKGROUND

Traumatic brain injury (TBI) is a major global health problem. Little research has addressed extracranial organ dysfunction following TBI, particularly myocardial injury. Using a sensitive marker of myocardial injury-high sensitivity troponin (hsTn)-we examined the incidence of early myocardial injury following TBI and explored its association with neurological outcomes following moderate-severe TBI.

METHODS

We conducted a pilot cohort study of 133 adult (age above 17 y) subjects enrolled in the TRACK-TBI 18-center prospective cohort study. Descriptive statistics were used to examine the incidence of myocardial injury (defined as hsTn >99th percentile for a standardized reference population) across TBI severities, and to explore the association of myocardial injury with a 6-month extended Glasgow Outcome Score among patients with moderate-severe TBI.

RESULTS

The mean (SD) age of the participants was 44 (17) years, and 87 (65%) were male. Twenty-six patients (20%) developed myocardial injury following TBI; myocardial injury was present in 15% of mild TBI patients and 29% of moderate-severe TBI patients (P=0.13). Median (interquartile range) hsTn values were 3.8 ng/L (2.1, 9.0), 5.8 ng/L (4.5, 34.6), and 10.2 ng/L (3.0, 34.0) in mild, moderate, and severe TBI participants, respectively (P=0.04). Overall, 11% of participants with moderate-severe TBI and myocardial injury experienced a good outcome (6-mo extended Glasgow Outcome Score≥5) at 6 months, compared with 65% in the group that did not experience myocardial injury (P=0.01).

CONCLUSIONS

Myocardial injury is common following TBI, with a likely dose-response relationship with TBI severity. Early myocardial injury was associated with poor 6-month clinical outcomes following moderate-severe TBI.

The Emergency Department Systolic Blood Pressure Relationship After Traumatic Brain Injury

BACKGROUND

Blood pressure alterations in patients with traumatic brain injury (TBI) have been shown to be associated with increased mortality. However, there is paucity of data describing the optimal emergency department (ED) systolic blood pressure (SBP) target during the initial evaluation. The aim of our study was to assess the association between SBP on presentation and mortality in patients with TBI.

METHODS

We performed a retrospective (2015-2016) review of the American College of Surgeons Trauma Quality Improvement Program database and included all adult (age ≥18y) trauma patients who had TBI on presentation. The outcome measure was in-hospital mortality at different ED-SBP values. A subanalysis by age and TBI severity in accordance with the Glasgow Coma Scale (GCS) was performed (mild (GCS ≥13), moderate (GCS 9-12), and severe (≤8)). Multivariate logistic regression analysis was performed.

RESULTS

A total of 94,411 adult trauma patients with TBI were included. Mean age was 59 ± 21y, 62% were male, and median GCS was 15 [14-15]. Mean SBP was 147 ± 28 mmHg, and overall mortality was 8.6%. The lowest rate of mortality was noticed at ED SBP between 110 and 149 mmHg, whereas the highest mortality was at admission SBP <90 mmHg and SBP >190 mmHg. On regression analysis, SBP between 130 and 149 mmHg (odds ratio = 0.92; P = 0.68) was not associated with increased odds of mortality relative to SBP between 110 and 129 mmHg. On subanalysis based on severity of TBI (mild 80.9%, moderate 5.3%, and severe 13.8%), patients with SBP between 110 and 149 mmHg were less likely to die across all TBI groups.

CONCLUSIONS

The optimal ED-SBP range for patients with TBI seems to be age and severity dependent. The optimum range might guide clinicians in developing resuscitation protocols for managing patients with TBI.

LEVEL OF EVIDENCE

Level III Prognostic.

Resuscitation Strategies for Traumatic Brain Injury

PURPOSE OF REVIEW

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality; however, little definitive evidence exists about most clinical management strategies. Here, we highlight important differences between two major guidelines, the 2016 Brain Trauma Foundation guidelines and the Lund Concept, along with recent pre-clinical and clinical data.

RECENT FINDINGS

While intracranial pressure (ICP) monitoring has been questioned, the majority of literature demonstrates benefit in severe TBI. The optimal cerebral perfusion pressure (CPP) and ICP are yet unknown, but likely as important is the concept of ICP burden. The evidence for anti-hypertensive therapy is strengthening. Decompressive craniectomy improves mortality, but at the cost of increased morbidity. Plasma-based resuscitation has demonstrated benefit in multiple pre-clinical TBI studies.

SUMMARY

The management of hemodynamics and intravascular volume are crucial in TBI. Based on recent evidence, ICP monitoring, anti-hypertensive therapy, minimal use of vasopressors/inotropes, and plasma resuscitation may improve outcomes.

Fluid management concepts for severe neurological illness: an overview

PURPOSE OF REVIEW

The acute care of a patient with severe neurological injury is organized around one relatively straightforward goal: avoid brain ischemia. A coherent strategy for fluid management in these patients has been particularly elusive, and a well considered fluid management strategy is essential for patients with critical neurological illness.

RECENT FINDINGS

In this review, several gaps in our collective knowledge are summarized, including a rigorous definition of volume status that can be practically measured; an understanding of how electrolyte derangements interact with therapy; a measurable endpoint against which we can titrate our patients' fluid balance; and agreement on the composition of fluid we should give in various clinical contexts.

SUMMARY

As the possibility grows closer that we can monitor the physiological parameters with direct relevance for neurological outcomes and the various complications associated with neurocritical illness, we may finally move away from static therapy recommendations, and toward individualized, precise therapy. Although we believe therapy should ultimately be individualized rather than standardized, it is clear that the monitoring tools and analytical methods used ought to be standardized to facilitate appropriately powered, prospective clinical outcome trials.

Hypertension After Severe Traumatic Brain Injury: Friend or Foe?

Traumatic brain injury (TBI) is a major public health problem, with severe TBI contributing to a large number of deaths and disability worldwide. Early hypotension has been linked with poor outcomes following severe TBI, and guidelines suggest early and aggressive management of hypotension after TBI. Despite these recommendations, no guidelines exist for the management of hypertension after severe TBI, although observational data suggests that early hypertension is also associated with an increased risk of mortality after severe TBI. The purpose of this review is to discuss the underlying pathophysiology of hypertension after TBI, provide an overview of the current clinical data on early hypertension after TBI, and discuss future research that should test the benefits and harms of treating high blood pressure in TBI patients.

Metoprolol improves survival in severe traumatic brain injury independent of heart rate control

BACKGROUND

Multiple prior studies have suggested an association between survival and beta-blocker administration in patients with severe traumatic brain injury (TBI). However, it is unknown whether this benefit of beta-blockers is dependent on heart rate control. The aim of this study was to assess whether rate control affects survival in patients receiving metoprolol with severe TBI. Our hypothesis was that improved survival from beta-blockade would be associated with a reduction in heart rate.

METHODS

We performed a 7-y retrospective analysis of all blunt TBI patients at a level-1 trauma center. Patients aged >16 y with head abbreviated injury scale 4 or 5, admitted to the intensive care unit (ICU) from the operating room or emergency room (ER), were included. Patients were stratified into two groups: metoprolol and no beta-blockers. Using propensity score matching, we matched the patients in two groups in a 1:1 ratio controlling for age, gender, race, admission vital signs, Glasgow coma scale, injury severity score, mean heart rate monitored during ICU admission, and standard deviation of heart rate during the ICU admission. Our primary outcome measure was mortality.

RESULTS

A total of 914 patients met our inclusion criteria, of whom 189 received beta-blockers. A propensity-matched cohort of 356 patients (178: metoprolol and 178: no beta-blockers) was created. Patients receiving metoprolol had higher survival than those patients who did not receive beta-blockers (78% versus 68%; P = 0.04); however, there was no difference in the mean heart rate (89.9 ± 13.9 versus 89.9 ± 15; P = 0.99). Nor was there a difference in the mean of standard deviation of the heart rates (14.7 ± 6.3 versus 14.4 ± 6.5; P = 0.65) between the two groups. In Kaplan-Meier survival analysis, patients who received metoprolol had a survival advantage (P = 0.011) compared with patients who did not receive any beta-blockers.

CONCLUSIONS

Our study shows an association with improved survival in patients with severe TBI receiving metoprolol, and this effect appears to be independent of any reduction in heart rate. We suggest that beta-blockers should be administered to all severe TBI patients irregardless of any perceived beta-blockade effect on heart rate.

Updates in the management of intracranial pressure in traumatic brain injury

PURPOSE OF REVIEW

Traumatic brain injury remains a common and often debilitating event across the world, producing significant burdens upon health and social care. Effective neurocritical care coupled with timely and appropriate neurosurgical intervention can produce significant improvements in patient outcome. There remains controversy about how best to manage intracranial pressure on the ICU; we review the recent literature addressing a number of key variables.

RECENT FINDINGS

Treatment of elevations in intracranial pressure can begin at the roadside and end on the ICU unit via a number of routes. Prehospital physician-led care may produce significant benefits in outcome which extend beyond airway management. Routine use of cooling worsens the respiratory outcomes without large improvement in neurological endpoints. The use of brain tissue oxygen monitoring is extending and increasingly used to guide management. Decompressive craniectomy in refractory intracranial hypertension has been associated with poor functional outcomes; a large multicentre trial is currently comparing it against barbiturate coma.

SUMMARY

The role of the neurointensivist in outcome for patients who suffer severe traumatic brain injury is key. Targeted therapies are allowing early detection and manipulation of brain ischaemia leading to more individualized treatment.