Early hypotension worsens neurological outcome in pediatric patients with moderately severe head trauma

Correlation between prehospital and in-hospital hypotension and outcomes after traumatic brain injury

BACKGROUND AND OBJECTIVE

Hypotension has a powerful effect on patient outcome after traumatic brain injury (TBI). The relative impact of hypotension occurring in the field versus during early hospital resuscitation is unknown. We evaluated the association between hypotension and mortality and non-mortality outcomes in four cohorts defined by where the hypotension occurred [neither prehospital nor hospital, prehospital only, hospital only, both prehospital and hospital].

METHODS

Subjects ≥10 years with major TBI were included. Standard statistics were used for unadjusted analyses. We used logistic regression, controlling for significant confounders, to determine the adjusted odds (aOR) for outcomes in each of the three cohorts.

RESULTS

Included were 12,582 subjects (69.8% male; median age 44 (IQR 26-61). Mortality by hypotension status: No hypotension: 9.2% (95%CI: 8.7-9.8%); EMS hypotension only: 27.8% (24.6-31.2%); hospital hypotension only: 45.6% (39.1-52.1%); combined EMS/hospital hypotension 57.6% (50.0-65.0%); (p < 0.0001). The aOR for death reflected the same progression: 1.0 (reference-no hypotension), 1.8 (1.39-2.33), 2.61 (1.73-3.94), and 4.36 (2.78-6.84), respectively. The proportion of subjects having hospital hypotension was 19.0% (16.5-21.7%) in those with EMS hypotension compared to 2.0% (1.8-2.3%) for those without (p < 0.0001). Additionally, the proportion of patients with TC hypotension was increased even with EMS "near hypotension" up to an SBP of 120 mmHg [(aOR 3.78 (2.97, 4.82)].

CONCLUSION

While patients with hypotension in the field or on arrival at the trauma center had markedly increased risk of death compared to those with no hypotension, those with prehospital hypotension that was not resolved before hospital arrival had, by far, the highest odds of death. Furthermore, TBI patients who had prehospital hypotension were five times more likely to arrive hypotensive at the trauma center than those who did not. Finally, even "near-hypotension" in the field was strongly and independently associated the risk of a hypotensive hospital arrival (<90 mmHg). These findings are supportive of the prehospital guidelines that recommend aggressive prevention and treatment of hypotension in major TBI.

Optimal Out-of-Hospital Blood Pressure in Major Traumatic Brain Injury: A Challenge to the Current Understanding of Hypotension

STUDY OBJECTIVE

Little is known about the out-of-hospital blood pressure ranges associated with optimal outcomes in traumatic brain injuries (TBI). Our objective was to evaluate the associations between out-of-hospital systolic blood pressure (SBP) and multiple hospital outcomes without assuming any predefined thresholds for hypotension, normotension, or hypertension.

METHODS

This was a preplanned secondary analysis from the Excellence in Prehospital Injury Care (EPIC) TBI study. Among patients (age ≥10 years) with major TBIs (Barell Matrix type 1 and/or Abbreviated Injury Scale-head severity ≥3) and lowest out-of-hospital SBPs of 40 to 299 mmHg, we utilized generalized additive models to summarize the distributions of various outcomes as smoothed functions of SBP, adjusting for important and significant confounders. The subjects who were enrolled in the study phase after the out-of-hospital TBI guideline implementation were used to validate the models developed from the preimplementation cohort.

RESULTS

Among 12,169 included cases, the mortality model revealed 3 distinct ranges: (1) a monotonically decreasing relationship between SBP and the adjusted probability of death from 40 to 130 mmHg, (2) lowest adjusted mortality from 130 to 180 mmHg, and (3) rapidly increasing mortality above 180 mmHg. A subanalysis of the cohorts with isolated TBIs and multisystem injuries with TBIs revealed SBP mortality patterns that were similar to each other and to that of the main analysis. While the specific SBP ranges varied somewhat for the nonmortality outcomes (hospital length of stay, ICU length of stay, discharge to skilled nursing/inpatient rehabilitation, and hospital charges), the patterns were very similar to that of mortality. In each model, validation was confirmed utilizing the postimplementation cohort.

CONCLUSION

Optimal adjusted mortality was associated with a surprisingly high SBP range (130 to 180 mmHg). Below this level, there was no point or range of inflection that would indicate a physiologically meaningful threshold for defining hypotension. Nonmortality outcomes showed very similar patterns. These findings highlight how sensitive the injured brain is to compromised perfusion at SBP levels that, heretofore, have been considered adequate or even normal. While the study design does did not allow us to conclude that the currently recommended treatment threshold (<90 mmHg) should be increased, the findings imply that the definition of hypotension in the setting of TBI is too low. Randomized trials evaluating treatment levels significantly higher than 90 mmHg are needed.

Associations of initial haemodynamic profiles and neurological outcomes in children with traumatic brain injury: a secondary analysis

INTRODUCTION

Initial low systolic blood pressure (SBP) in paediatric traumatic brain injury (TBI) is associated with mortality. There is limited literature on how other haemodynamic parameters including heart rate (HR); diastolic blood pressure (DBP); mean arterial pressure (MAP); and shock index, paediatric age-adjusted (SIPA) affect not only mortality but also long-term neurological outcomes in paediatric TBI. We aimed to analyse the associations of these haemodynamic variables (HR, SBP, MAP, DBP and SIPA) with mortality and long-term neurological outcomes in isolated moderate-to-severe paediatric TBI.

METHODS

This was a secondary analysis of our primary study that analysed the association of TBI-associated coagulopathy with mortality and neurological outcome in isolated, moderate-to-severe paediatric head injury. A trauma registry-based, retrospective study of children <18 years old who presented to the emergency department with isolated, moderate-to-severe TBI from January 2010 to December 2016 was conducted. The association between initial haemodynamic variables and less favourable outcomes using Glasgow Outcome Scale-Extended Paediatric) at 6 months post injury was analysed using logistic regression.

RESULTS

Among 152 children analysed, initial systolic and diastolic hypotension (<5th percentile) (OR) for SBP 11.40, 95% CI 3.60 to 36.05, p<0.001; OR for DBP 15.75, 95% CI 3.09 to 80.21, p<0.001) and Glasgow Coma Scale scores <8 (OR 14.50, 95% CI 3.65 to 57.55, p<0.001) were associated with 'moderate-to-severe neurological disabilities', 'vegetative state' and 'death'. After adjusting for confounders, only SBP was significant (adjusted OR 5.68, 95% CI 1.40 to 23.08, p=0.015).

CONCLUSIONS

Initial systolic hypotension was independently associated with mortality and moderate-to-severe neurological deficits at 6 months post injury. Further work is required to understand if early correction of hypotension will improve long-term outcomes.

Mean Arterial Pressure and Discharge Outcomes in Severe Pediatric Traumatic Brain Injury

BACKGROUND AND OBJECTIVE

Optimizing blood pressure is an important target for intervention following pediatric traumatic brain injury (TBI). The existing literature has examined the association between systolic blood pressure (SBP) and outcomes. Mean arterial pressure (MAP) is a better measure of organ perfusion than SBP and is used to determine cerebral perfusion pressure but has not been previously examined in relation to outcomes after pediatric TBI. We aimed to evaluate the strength of association between MAP-based hypotension early after hospital admission and discharge outcome and to contrast the relative strength of association of hypotension with outcome between MAP-based and SBP-based blood pressure percentiles.

METHODS

We examined the association between lowest age-specific MAP percentile within 12 h after pediatric intensive care unit admission and poor discharge outcome (in-hospital death or transfer to a skilled nursing facility) in children with severe (Glasgow Coma Scale score < 9) TBI who survived at least 12 h. Poisson regression results were adjusted for maximum head Abbreviated Injury Scale (AIS) severity score, maximum nonhead AIS, and vasoactive medication use. We also examined the ability of lowest MAP percentile during the first 12 h to predict discharge outcomes using receiver operating curve characteristic analysis without adjustment for covariates. We contrasted the predictive ability and the relative strength of association of blood pressure with outcome between MAP and SBP percentiles.

RESULTS

Data from 166 children aged < 18 years were examined, of whom 20.4% had a poor discharge outcome. Poor discharge outcome was most common among patients with lowest MAP < 5th percentile (42.9%; aRR 5.3 vs. 50-94th percentile, 95% CI 1.2, 23.0) and MAP 5-9th percentile (40%; aRR 8.5, 95% CI 1.9, 38.7). Without adjustment for injury severity or vasoactive medication use, lowest MAP percentile was moderately predictive of poor discharge outcome (AUC: 0.75, 95% CI 0.66, 0.85). In contrast, lowest SBP was associated with poor discharge outcome only for the < 5th percentile (50%; aRR 5.4, 95% CI 1.3, 22.2). Lowest SBP percentile was moderately predictive of poor discharge outcome (AUC: 0.82, 95% CI 0.74, 0.91).

CONCLUSIONS

In children with severe TBI, a single MAP < 10th percentile during the first 12 h after Pediatric Intensive Care Unit admission was associated with poor discharge outcome. Lowest MAP percentile during the first 12 h was moderately predictive of poor discharge outcome. Lowest MAP percentile was more strongly associated with outcome than lowest SBP percentile but had slightly lower predictive ability than SBP.

An unambiguous definition of pediatric hypotension is still lacking: Gaps between two percentile-based definitions and Pediatric Advanced Life Support/Advanced Trauma Life Support guidelines

BACKGROUND

Data are lacking to provide cutoffs for hypotension in children based on outcome studies and Pediatric Advanced Life Support (PALS), and Advanced Trauma Life Support (ATLS) definitions are based on normal populations. The goal of this study was to compare different normal population based cutoffs including fifth percentile of systolic blood pressure (P5-SBP) in children and adolescents from the German Health Examination Survey for Children and Adolescents (KiGGS), US population data (Fourth Report), and cutoffs from PALS and ATLS guidelines.

METHODS

Fifth percentile of systolic blood pressure according to age, sex, and height was modeled based on standardized resting oscillometric BP measurements (12,199 children aged 3-17 years) from KiGGS 2003-2006. In addition, we applied the age-adjusted pediatric shock index in the KiGGS study.

RESULTS

The KiGGS P5-SBP was on average 7 mm Hg higher than Fourth Report P5-SBP (5-10 mm Hg depending on age-sex group). For children aged 3 to 9 years, KIGGS P5-SBP at median height follows the formula 82 mm Hg + age; for age 10 to 17 years, the increase was not linear and is presented in a simplified table. Pediatric Advanced Life Support/ATLS thresholds were between KiGGS and Fourth Report until age of 11 years. The adult threshold of 90 mm Hg was reached by KiGGS P5-SBP median height at 8 years, PALS/ATLS at age of 10 years, and Fourth Report P5-SBP at 12 years. The pediatric shock index, which is supposed to identify severely injured children, was exceeded by 2.3% nonacutely ill KiGGS participants.

CONCLUSION

Our study shows that percentile cutoffs vary by reference population. The 90 mm Hg cutoff for adolescents targets only those in the less than 1% of the low SBP range and represents an undertriage compared with P5 at younger ages according to both KiGGS and Fourth Report. Finally, current pediatric shock index cutoffs when applied to a healthy cohort lead to a relevant percentage of false positives.

LEVEL OF EVIDENCE

Epidemiologic/prognostic, level III.

Improving Understanding and Outcomes of Traumatic Brain Injury Using Bidirectional Translational Research

Recent clinical trials in traumatic brain injury (TBI) have failed to demonstrate therapeutic effects even when there appears to be good evidence for efficacy in one or more appropriate pre-clinical models. While existing animal models mimic the injury, difficulties in translating promising therapeutics are exacerbated by the lack of alignment of discrete measures of the underlying injury pathology between the animal models and human subjects. To address this mismatch, we have incorporated reverse translation of bedside experience to inform pre-clinical studies in a large animal (pig) model of TBI that mirror practical clinical assessments. Cerebral autoregulation is impaired after TBI, contributing to poor outcome. Cerebral perfusion pressure (CPP) is often normalized by use of vasoactive agents to increase mean arterial pressure (MAP) and thereby limit impairment of cerebral autoregulation and neurological deficits. Vasoactive agents clinically used to elevate MAP to increase CPP after TBI, such as phenylephrine (Phe), dopamine (DA), norepinephrine (NE), and epinephrine (EPI), however, have not been compared sufficiently regarding effect on CPP, autoregulation, and survival after TBI, and clinically, current vasoactive agent use is variable. The cerebral effects of these clinically commonly used vasoactive agents are not known. This review will emphasize pediatric work and will describe bidirectional translational studies using a more human-like animal model of TBI to identify better therapeutic strategies to improve outcome post-injury. These studies in addition investigated the mechanism(s) involved in improvement of outcome in the setting of TBI.

Normobaric hyperoxia in wartime pediatric trauma casualties

BACKGROUND

Mounting evidence suggests hyperoxia therapy may be harmful. We describe injury characteristics and survival outcomes for pediatric trauma casualties in Iraq and Afghanistan, stratified by partial pressure of arterial oxygen (PaO2). Secondarily, we performed subgroup analyses for severe traumatic brain injury (TBI) and massive transfusion of blood products (MT).

METHODS

We utilized Department of Defense Trauma Registry data. We included subjects <18 years. We excluded subjects without an arterial blood gas (ABG). We stratified subjects as hyperoxemia (PaO2 100-300 mmHg) and extreme hyperoxemia (PaO2 >300 mmHg).

RESULTS

January 2007-January 2016, 3439 pediatric encounters were in the database. Of those, 1323 had an ABG, with 291 (22%) demonstrating hyperoxemia and 43 (3.3%) extreme hyperoxemia. The median age was 8, most were male (76%) in Afghanistan (69%), and injured by explosive (42%). There were no significant differences in survival between subjects with no hyperoxemia, hyperoxemia, and extreme hyperoxemia (92% vs 87% vs 86%; p = 0.078). Also, there were no significant differences in survival between groups among TBI and MT subjects, and there were no increased odds of survival between groups on multivariable regression analyses.

CONCLUSIONS

Hyperoxemia was common among hospitalized, wartime pediatric trauma casualties in Iraq and Afghanistan that underwent ABG analysis. Survival to hospital discharge rates were not significantly different between subjects with hyperoxemia and subjects without hyperoxemia.

Blood Pressure Thresholds and Mortality in Pediatric Traumatic Brain Injury

BACKGROUND

Hypotension after pediatric traumatic brain injury (TBI) is associated with poor outcomes, but definitions of low systolic blood pressure (SBP) vary. Age- and sex-specific, percentile-based definitions of hypotension may help to better identify children at risk for poor outcomes compared with traditional thresholds recommended in pediatric trauma care.

METHODS

Using the National Trauma Data Bank between 2007 and 2014, we conducted a retrospective cohort study of children with isolated severe TBI. We classified admission SBP into 5 percentile categories according to population-based values: (1) SBP less than the fifth percentile, (2) SBP in the fifth to 24th percentile, (3) SBP in the 25th to 74th percentile, (4) SBP in the 75th to 94th percentile, and (5) SBP ≥95th percentile. These definitions were compared with the American College of Surgeons (ACS) hypotension definition. The association between SBP percentiles and in-hospital mortality was analyzed by using multivariable Poisson regression models.

RESULTS

There were 10 473 children with severe TBI included in this study. There were 2388 (22.8%) patients who died while in the hospital. Compared with SBP in the 75th to 94th percentile, mortality was higher with SBP less than the fifth percentile (relative risk [RR] 3.2; 95% confidence interval [CI] 2.9-3.6), SBP in the fifth to 24th percentile (RR 2.3; 95% CI 2.0-2.7), and SBP in the 25th to 74th percentile (RR 1.4; 95% CI 1.2-1.6). An increased risk of mortality with SBP <75th percentile was present across all age subgroups. SBP targets using the ACS hypotension definition were higher than the fifth percentile hypotension definition, but were lower than the 75th percentile hypotension definition.

CONCLUSIONS

Admission SBP <75th percentile was associated with a higher risk of in-hospital mortality after isolated severe TBI in children. SBP targets based on the 75th percentile were higher compared with traditional ACS targets. Percentile-based SBP targets should be considered in defining hypotension in pediatric TBI.

Timely Hemodynamic Resuscitation and Outcomes in Severe Pediatric Traumatic Brain Injury: Preliminary Findings

OBJECTIVES

Early resuscitation may improve outcomes in pediatric traumatic brain injury (TBI). We examined the association between timely treatment of hypotension and hypoxia during early care (prehospital or emergency department locations) and discharge outcomes in children with severe TBI.

METHODS

Hypotension was defined as systolic blood pressure less than 70 + 2 (age in years), and hypoxia was defined as PaO2 less than 60 mm Hg or oxygen saturation less than 90% in accordance with the 2003 Brain Trauma Foundation guidelines. Timely treatment of hypotension and hypoxia during early care was defined as the treatment within 30 minutes of a documented respective episode. Two hundred thirty-six medical records of children younger than 18 years with severe TBI from 5 regional pediatric trauma centers were examined. Main outcomes were in-hospital mortality and discharge Glasgow Outcome Scale (GOS) score.

RESULTS

Hypotension occurred in 26% (60/234) during early care and was associated with in-hospital mortality (23.3% vs 8.6%; P = 0.01). Timely treatment of hypotension during early care occurred in 92% (55/60) by use of intravenous fluids, blood products, or vasopressors and was associated with reduced in-hospital mortality [adjusted relative risk (aRR), 0.46; 95% confidence interval, 0.24-0.90] and less likelihood of poor discharge GOS (aRR, 0.54; 95% confidence interval, 0.39-0.76) when compared to children with hypotension who were not treated in a timely manner. Early hypoxia occurred in 17% (41/236) and all patients received timely oxygen treatment.

CONCLUSIONS

Timely resuscitation during early care was common and associated with lower in-hospital mortality and favorable discharge GOS in severe pediatric TBI.

Severely Elevated Blood Pressure and Early Mortality in Children with Traumatic Brain Injuries: The Neglected End of the Spectrum

Introduction

In adults with traumatic brain injuries (TBI), hypotension and hypertension at presentation are associated with mortality. The effect of age-adjusted blood pressure in children with TBI has been insufficiently studied. We sought to determine if age-adjusted hypertension in children with severe TBI is associated with mortality.

Methods

This was a retrospective analysis of the Department of Defense Trauma Registry (DoDTR) between 2001 and 2013. We included for analysis patients <18 years with severe TBI defined as Abbreviated Injury Severity (AIS) scores of the head ≥3. We defined hypertension as moderate for systolic blood pressures (SBP) between the 95^th and 99^th percentile for age and gender and severe if greater than the 99th percentile. Hypotension was defined as SBP <90 mmHg for children >10 years or < 70mmHg + (2 × age) for children ≤10 years. We performed multivariable logistic regression and Cox regression to determine if BP categories were associated with mortality.

Results

Of 4,990 children included in the DoDTR, 740 met criteria for analysis. Fifty patients (6.8%) were hypotensive upon arrival to the ED, 385 (52.0%) were normotensive, 115 (15.5%) had moderate hypertension, and 190 (25.7%) had severe hypertension. When compared to normotensive patients, moderate and severe hypertension patients had similar Injury Severity Scores, similar AIS head scores, and similar frequencies of neurosurgical procedures. Multivariable logistic regression demonstrated that hypotension (odd ratio [OR] 2.85, 95 confidence interval [CI] 1.26–6.47) and severe hypertension (OR 2.58, 95 CI 1.32–5.03) were associated with increased 24-hour mortality. Neither hypotension (Hazard ratio (HR) 1.52, 95 CI 0.74–3.11) nor severe hypertension (HR 1.65, 95 CI 0.65–2.30) was associated with time to mortality.

Conclusion

Pediatric age-adjusted hypertension is frequent after severe TBI. Severe hypertension is strongly associated with 24-hour mortality. Pediatric age-adjusted blood pressure needs to be further evaluated as a critical marker of early mortality.

Association of Out-of-Hospital Hypotension Depth and Duration With Traumatic Brain Injury Mortality

STUDY OBJECTIVE

Out-of-hospital hypotension has been associated with increased mortality in traumatic brain injury. The association of traumatic brain injury mortality with the depth or duration of out-of-hospital hypotension is unknown. We evaluated the relationship between the depth and duration of out-of-hospital hypotension and mortality in major traumatic brain injury.

METHODS

We evaluated adults and older children with moderate or severe traumatic brain injury in the preimplementation cohort of Arizona's statewide Excellence in Prehospital Injury Care study. We used logistic regression to determine the association between the depth-duration dose of hypotension (depth of systolic blood pressure <90 mm Hg integrated over duration [minutes] of hypotension) and odds of inhospital death, controlling for significant confounders.

RESULTS

There were 7,521 traumatic brain injury cases included (70.6% male patients; median age 40 years [interquartile range 24 to 58]). Mortality was 7.8% (95% confidence interval [CI] 7.2% to 8.5%) among the 6,982 patients without hypotension (systolic blood pressure ≥90 mm Hg) and 33.4% (95% CI 29.4% to 37.6%) among the 539 hypotensive patients (systolic blood pressure <90 mm Hg). Mortality was higher with increased hypotension dose: 0.01 to 14.99 mm Hg-minutes 16.3%; 15 to 49.99 mm Hg-minutes 28.1%; 50 to 141.99 mm Hg-minutes 38.8%; and greater than or equal to 142 mm Hg-minutes 50.4%. Log2 (the logarithm in base 2) of hypotension dose was associated with traumatic brain injury mortality (adjusted odds ratio 1.19 [95% CI 1.14 to 1.25] per 2-fold increase of dose).

CONCLUSION

In this study, the depth and duration of out-of-hospital hypotension were associated with increased traumatic brain injury mortality. Assessments linking out-of-hospital blood pressure with traumatic brain injury outcomes should consider both depth and duration of hypotension.

Mortality and Prehospital Blood Pressure in Patients With Major Traumatic Brain Injury: Implications for the Hypotension Threshold

IMPORTANCE

Current prehospital traumatic brain injury guidelines use a systolic blood pressure threshold of less than 90 mm Hg for treating hypotension for individuals 10 years and older based on studies showing higher mortality when blood pressure drops below this level. However, the guidelines also acknowledge the weakness of the supporting evidence.

OBJECTIVE

To evaluate whether any statistically supportable threshold between systolic pressure and mortality emerges from the data a priori, without assuming that a cut point exists.

DESIGN, SETTING, AND PARTICIPANTS

Observational evaluation of a large prehospital database established as a part of the Excellence in Prehospital Injury Care Traumatic Brain Injury Study. Patients from the preimplementation cohort (January 2007 to March 2014) 10 years and older with moderate or severe traumatic brain injury (Barell Matrix Type 1 classification, International Classification of Diseases, Ninth Revision head region severity score of 3 or greater, and/or Abbreviated Injury Scale head-region severity score of 3 or greater) and a prehospital systolic pressure between 40 and 119 mm Hg were included. The generalized additive model and logistic regression were used to determine the association between systolic pressure and probability of death, adjusting for significant/important confounders.

MAIN OUTCOMES AND MEASURES

The main outcome measure was in-hospital mortality.

RESULTS

Among the 3844 included patients, 2565 (66.7%) were male, and the median (range) age was 35 (10-99) years. The model revealed a monotonically decreasing association between systolic pressure and adjusted probability of death across the entire range (ie, from 40 to 119 mm Hg). Each 10-point increase of systolic pressure was associated with a decrease in the adjusted odds of death of 18.8% (adjusted odds ratio, 0.812; 95% CI, 0.748-0.883). Thus, the adjusted odds of mortality increased as much for a drop from 110 to 100 mm Hg as for a drop from 90 to 80 mm Hg, and so on throughout the range.

CONCLUSIONS AND RELEVANCE

We found a linear association between lowest prehospital systolic blood pressure and severity-adjusted probability of mortality across an exceptionally wide range. There is no identifiable threshold or inflection point between 40 and 119 mm Hg. Thus, in patients with traumatic brain injury, the concept that 90 mm Hg represents a unique or important physiological cut point may be wrong. Furthermore, clinically meaningful hypotension may not be as low as current guidelines suggest. Randomized trials evaluating treatment levels significantly above 90 mm Hg are needed.

The Effect of Combined Out-of-Hospital Hypotension and Hypoxia on Mortality in Major Traumatic Brain Injury

STUDY OBJECTIVE

Survival is significantly reduced by either hypotension or hypoxia during the out-of-hospital management of major traumatic brain injury. However, only a handful of small studies have investigated the influence of the combination of both hypotension and hypoxia occurring together. In patients with major traumatic brain injury, we evaluate the associations between mortality and out-of-hospital hypotension and hypoxia separately and in combination.

METHODS

All moderate or severe traumatic brain injury cases in the preimplementation cohort of the Excellence in Prehospital Injury Care study (a statewide, before/after, controlled study of the effect of implementing the out-of-hospital traumatic brain injury treatment guidelines) from January 1, 2007, to March 31, 2014, were evaluated (exclusions: <10 years, out-of-hospital oxygen saturation ≤10%, and out-of-hospital systolic blood pressure <40 or >200 mm Hg). The relationship between mortality and hypotension (systolic blood pressure <90 mm Hg) or hypoxia (saturation <90%) was assessed with multivariable logistic regression, controlling for Injury Severity Score, head region severity, injury type (blunt versus penetrating), age, sex, race, ethnicity, payer, interhospital transfer, and trauma center.

RESULTS

Among the 13,151 patients who met inclusion criteria (median age 45 years; 68.6% men), 11,545 (87.8%) had neither hypotension nor hypoxia, 604 (4.6%) had hypotension only, 790 (6.0%) had hypoxia only, and 212 (1.6%) had both hypotension and hypoxia. Mortality for the 4 study cohorts was 5.6%, 20.7%, 28.1%, and 43.9%, respectively. The crude and adjusted odds ratios for death within the cohorts, using the patients with neither hypotension nor hypoxia as the reference, were 4.4 and 2.5, 6.6 and 3.0, and 13.2 and 6.1, respectively. Evaluation for an interaction between hypotension and hypoxia revealed that the effects were additive on the log odds of death.

CONCLUSION

In this statewide analysis of major traumatic brain injury, combined out-of-hospital hypotension and hypoxia were associated with significantly increased mortality. This effect on survival persisted even after controlling for multiple potential confounders. In fact, the adjusted odds of death for patients with both hypotension and hypoxia were more than 2 times greater than for those with either hypotension or hypoxia alone. These findings seem supportive of the emphasis on aggressive prevention and treatment of hypotension and hypoxia reflected in the current emergency medical services traumatic brain injury treatment guidelines but clearly reveal the need for further study to determine their influence on outcome.

Outcome Predictors in Pediatric Head Trauma: A Study of Clinicoradiological Factors

Introduction:

Traumatic injuries are the leading cause of death and a major cause of disability among children. About 70%–80% of the accidental deaths in pediatric age group result directly from central nervous system lesions.

Methods:

The purpose of our study was to study all the patients of ≤18 years of age with head or spinal injury admitted in neurointensive care unit at our center, an apex trauma center in a developing country, between June 2009 and September 2011. We retrospectively analyzed various factors including type of injury, mode of injury, admission Glasgow coma score (in case of head injury), and mortality rate.

Observations:

The study population consisted of 264 injured children. Mean age was 8.3 ± 5.6 years (range 5 months to 18 years). Forty percent of patients were within 1–5-year age group. Head injury accounted for 89% of cases and 11% of cases were spinal injury patients. Low-velocity trauma was the most common mode of injury, accounting for 74% of the cases. The percentage of patients with mild, moderate, and severe head injury were 38%, 15%, and 47%, respectively, in the head injury group. Mortality in head injury patients was 18% and in spinal injury patients was 9%. Operative intervention was done in 56% of patients. Predictors of mortality included severe head injury, hospital stay <7 days, pneumothorax, the presence of hypotension, and deranged coagulation parameters.

Conclusions:

Head injury is much more common than spinal injury in pediatric patients and fall from height being the most common mode of injury. Severe head injury, hospital stay <7 days, pneumothorax, presence of hypotension, and deranged coagulation parameters are predictors of poor outcome.

Mannitol or hypertonic saline in the setting of traumatic brain injury: What have we learned?

Background:

Intracranial hypertension, defined as an intracranial pressure (ICP) >20 mmHg for a period of more than 5 min, worsens neurologic outcome in traumatic brain injury (TBI). While several mechanisms contribute to poor outcome, impaired cerebral perfusion appears to be a highly significant common denominator. Management guidelines from the Brain Trauma Foundation recommend measuring ICP to guide therapy. In particular, hyperosmolar therapy, which includes mannitol or hypertonic saline (HTS), is frequently administered to reduce ICP. Currently, mannitol (20%) is considered the gold standard hyperosmolar agent. However, HTS is increasingly used in this setting. This review sought to compare the efficacy of mannitol to HTS in severe TBI.

Methods:

The PubMed database was used to systematically search for articles comparing mannitol to HTS in severe TBI. The following medical subject headings were used: HTS, sodium lactate, mannitol, ICP, intracranial hypertension, and TBI. We included both prospective and retrospective randomized controlled studies of adult patients with intracranial hypertension as a result of severe TBI who received hyperosmolar therapy.

Results:

Out of 45 articles, seven articles were included in our review: 5 were prospective, randomized trials; one was a prospective, nonrandomized trial; and one was a retrospective, cohort study.

Conclusions:

While all seven studies found that both mannitol and HTS were effective in reducing ICP, there was heterogeneity with regard to which agent was most efficacious.

A pediatric specific shock index in combination with GMS identifies children with life threatening or severe traumatic brain injury

PURPOSE

We have previously demonstrated that a shock index, pediatric age adjusted (SIPA) accurately identifies severely blunt injured children. We aimed to determine if SIPA could more accurately identify children with severe traumatic brain injury (TBI) than hypotension alone.

METHODS

We performed subset analysis of those children with TBI among a cohort of children age 4-16 years with blunt trauma and injury severity score ≥15 from 1/07 to 6/13. We evaluated the ability of four markers to identify the most severely brain injured children. Markers included hypotension, elevated SIPA, abnormal GCS motor score (GMS), and elevated SIPA or abnormal GMS. We aimed to determine which of these four markers had the highest sensitivity in identifying severely injured children.

RESULTS

Three hundred and ninety-two (392) children were included. Hypotension was present in 24 patients (6%); elevated SIPA in 106 (27 %), abnormal GMS in 172 (44%), and elevated SIPA or abnormal GMS in 206 (53%). All markers were able to accurately identify severely injured children with TBI. Elevated SIPA or abnormal GMS identified a greater percentage of patients with each of seven complications with higher sensitivity than each of the three other markers.

CONCLUSION

Among blunt injured children with TBI, elevated SIPA or abnormal GMS identifies severely brain injured children.

Evidence-based assessment of severe pediatric traumatic brain injury and emergent neurocritical care

Pediatric traumatic brain injury accounts for approximately 474,000 emergency department visits, 37,000 hospitalizations, and 3,000 deaths in children 14 years and younger annually in the United States. Acute neurocritical care in children has advanced with specialized pediatric trauma centers and emergency medical services. This article reviews pediatric-specific diagnosis, management, and medical decision making related to the neurocritical care of severe traumatic brain injury.

Acute care clinical indicators associated with discharge outcomes in children with severe traumatic brain injury

OBJECTIVE

The effect of the 2003 severe pediatric traumatic brain injury (TBI) guidelines on outcomes has not been examined. We aimed to develop a set of acute care guideline-influenced clinical indicators of adherence and tested the relationship between these indicators during the first 72 hours after hospital admission and discharge outcomes.

DESIGN

Retrospective multicenter cohort study.

SETTING

Five regional pediatric trauma centers affiliated with academic medical centers.

PATIENTS

Children under 18 years with severe traumatic brain injury (admission Glasgow Coma Scale score ≤ 8, International Classification of Diseases, 9th Edition, diagnosis codes of 800.0-801.9, 803.0-804.9, 850.0-854.1, 959.01, 950.1-950.3, 995.55, maximum head abbreviated Injury Severity Score ≥ 3) who received tracheal intubation for at least 48 hours in the ICU between 2007 and 2011 were examined.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Total percent adherence to the clinical indicators across all treatment locations (prehospital, emergency department, operating room, and ICU) during the first 72 hours after admission to study center were determined. Main outcomes were discharge survival and Glasgow Outcome Scale score. Total adherence rate across all locations and all centers ranged from 68% to 78%. Clinical indicators of adherence were associated with survival (adjusted hazard ratios, 0.94; 95% CI, 0.91-0.96). Three indicators were associated with survival: absence of prehospital hypoxia (adjusted hazard ratios, 0.20; 95% CI, 0.08-0.46), early ICU start of nutrition (adjusted hazard ratios, 0.06; 95% CI, 0.01-0.26), and ICU PaCO2 more than 30 mm Hg in the absence of radiographic or clinical signs of cerebral herniation (adjusted hazard ratios, 0.22; 95% CI, 0.06-0.8). Clinical indicators of adherence were associated with favorable Glasgow Outcome Scale among survivors (adjusted hazard ratios, 0.99; 95% CI, 0.98-0.99). Three indicators were associated with favorable discharge Glasgow Outcome Scale: all operating room cerebral perfusion pressure more than 40 mm Hg (adjusted relative risk, 0.61; 95% CI, 0.58-0.64), all ICU cerebral perfusion pressure more than 40 mm Hg (adjusted relative risk, 0.73; 95% CI, 0.63-0.84), and no surgery (any type; adjusted relative risk, 0.68; 95% CI, 0.53- 0.86).

CONCLUSIONS

Acute care clinical indicators of adherence to the Pediatric Guidelines were associated with significantly higher discharge survival and improved discharge Glasgow Outcome Scale. Some indicators were protective, regardless of treatment location, suggesting the need for an interdisciplinary approach to the care of children with severe traumatic brain injury.

Evaluation of the impact of implementing the emergency medical services traumatic brain injury guidelines in Arizona: the Excellence in Prehospital Injury Care (EPIC) study methodology

Traumatic brain injury (TBI) exacts a great toll on society. Fortunately, there is growing evidence that the management of TBI in the early minutes after injury may significantly reduce morbidity and mortality. In response, evidence-based prehospital and in-hospital TBI treatment guidelines have been established by authoritative bodies. However, no large studies have yet evaluated the effectiveness of implementing these guidelines in the prehospital setting. This article describes the background, design, implementation, emergency medical services (EMS) treatment protocols, and statistical analysis of a prospective, controlled (before/after), statewide study designed to evaluate the effect of implementing the EMS TBI guidelines-the Excellence in Prehospital Injury Care (EPIC) study (NIH/NINDS R01NS071049, "EPIC"; and 3R01NS071049-S1, "EPIC4Kids"). The specific aim of the study is to test the hypothesis that statewide implementation of the international adult and pediatric EMS TBI guidelines will significantly reduce mortality and improve nonmortality outcomes in patients with moderate or severe TBI. Furthermore, it will specifically evaluate the effect of guideline implementation on outcomes in the subgroup of patients who are intubated in the field. Over the course of the entire study (~9 years), it is estimated that approximately 25,000 patients will be enrolled.

Factors associated with hemispheric hypodensity after subdural hematoma following abusive head trauma in children

Abusive head trauma (AHT) is a unique form of pediatric TBI with increased mortality and neurologic sequelae. Hemispheric hypodensity (HH) in association with subdural blood after AHT has been described. Though risk factors for HH are not understood, we hypothesized that risk factors could be identified. We retrospectively enrolled children under 5 years with TBI secondary to AHT (child advocacy diagnosis) who had undergone initial and interval brain imaging. Records were interrogated for prearrival and in-hospital physiologic and radiographic findings. HH was determined by a blinded observer. Twenty-four children were enrolled and 13 developed HH. HH was not significantly associated with age, initial Glascow Coma Scale, or mortality. Pediatric Intensity Level of Therapy (PILOT) scores (p=0.01) and daily maximal intracranial pressure (ICPmax; p=0.037) were higher in HH. Hypoxia, hypotension, cardiopulmonary arrest, need for blood transfusion, and daily blood glucoses tended to be greater in HH. Whereas all children with HH had acute subdural hematoma (SBH), many children without HH also had subdural blood; the presence of skull fracture was more likely in the children who did not develop HH (p=0.04), but no other intracranial radiographic pattern of injury was associated with HH. Surgical intervention did not appear to protect against development of HH. A variety of insults associated with ischemia, including intracranial hypertension, ICP-directed therapies, hypoxia, hypotension, and cardiac arrest, occurred in the children who developed HH. Given the morbidity and mortality of this condition, larger studies to identify mechanisms leading to the development of HH and mitigating clinical approaches are warranted.

Prehospital intubation in patients with isolated severe traumatic brain injury: a 4-year observational study

Objectives. To study the effect of prehospital intubation (PHI) on survival of patients with isolated severe traumatic brain injury (ISTBI). Method. Retrospective analyses of all intubated patients with ISTBI between 2008 and 2011 were studied. Comparison was made between those who were intubated in the PHI versus in the trauma resuscitation unit (TRU). Results. Among 1665 TBI patients, 160 met the inclusion criteria (105 underwent PHI, and 55 patients were intubated in TRU). PHI group was younger in age and had lower median scene motor GCS (P = 0.001). Ventilator days and hospital length of stay (P = 0.01 and 0.006, resp.) were higher in TRUI group. Mean ISS, length of stay, initial blood pressure, pneumonia, and ARDS were comparable among the two groups. Mortality rate was higher in the PHI group (54% versus 31%, P = 0.005). On multivariate regression analysis, scene motor GCS (OR 0.55; 95% CI 0.41-0.73) was an independent predictor for mortality. Conclusion. PHI did not offer survival benefit in our group of patients with ISTBI based on the head AIS and the scene motor GCS. However, more studies are warranted to prove this finding and identify patients who may benefit from this intervention.

Age-specific cerebral perfusion pressure thresholds and survival in children and adolescents with severe traumatic brain injury*

OBJECTIVES

Evidence-based traumatic brain injury guidelines support cerebral perfusion pressure thresholds for adults at a class 2 level, but evidence is lacking in younger patients. The purpose of this study is to identify the impact of age-specific cerebral perfusion pressure thresholds on short-term survival among patients with severe traumatic brain injury.

DESIGN

Institutional review board-approved, prospective, observational cohort study.

SETTING

Level I or II trauma centers in New York State.

PATIENTS

Data on all patients with a postresuscitation Glasgow Coma Score less than 9 were added in the Brain Trauma Foundation prospective New York State TBI-trac database.

MEASUREMENTS AND MAIN RESULTS

We calculated the survival rates and relative risks of mortality for patients with severe traumatic brain injury based on predefined age-specific cerebral perfusion pressure thresholds. A higher threshold and a lower threshold were defined for each age group: 60 and 50 mm Hg for 12 years old or older, 50 and 35 mm Hg for 6-11 years, and 40 and 30 mm Hg for 0-5 years. Patients were stratified into age groups of 0-11, 12-17, and 18 years old or older. Three exclusive groups of CPP-L (events below low cerebral perfusion pressure threshold), CPP-B (events between high and low cerebral perfusion pressure thresholds), and CPP-H (events above high cerebral perfusion pressure threshold) were defined. As an internal control, we evaluated the associations between cerebral perfusion pressure events and events of hypotension and elevated intracranial pressure. Survival was significantly higher in 0-11 and 18 years old or older age groups for patients with CPP-H events compared with those with CPP-L events. There was a significant decrease in survival with prolonged exposure to CPP-B events for the 0-11 and 18 years old and older age groups when compared with the patients with CPP-H events (p = 0.0001 and p = 0.042, respectively). There was also a significant decrease in survival with prolonged exposure to CPP-L events in all age groups compared with the patients with CPP-H events (p< 0.0001 for 0- to 11-yr olds, p = 0.0240 for 12- to 17-yr olds, and p < 0.0001 for 18-yr old and older age groups). The 12- to 17-year olds had a significantly higher likelihood of survival compared with adults with prolonged exposure to CPP-L events (< 50 mm Hg). CPP-L events were significantly related to systemic hypotension for the 12- to 17-year-old group (p = 0.004) and the 18-year-old and older group (p < 0.0001). CPP-B events were significantly related to systemic hypotension in the 0- to 11-year-old group (p = 0.014). CPP-B and CPP-L events were significantly related to elevated intracranial pressure in all age groups.

CONCLUSIONS

Our data provide new evidence that cerebral perfusion pressure targets should be age specific. Furthermore, cerebral perfusion pressure goals above 50 or 60 mm Hg in adults, above 50 mm Hg in 6- to 17-year olds, and above 40 mm Hg in 0- to 5-year olds seem to be appropriate targets for treatment-based studies. Systemic hypotension had an inconsistent relationship to events of low cerebral perfusion pressure, whereas elevated intracranial pressure was significantly related to all low cerebral perfusion pressure events across all age groups. This may impart a clinically important difference in care, highlighting the necessity of controlling intracranial pressure at all times, while targeting systolic blood pressure in specific instances.

Is therapeutic hypothermia beneficial for pediatric patients with traumatic brain injury? A meta-analysis

PURPOSE

Hypothermia therapy shows its unique potential for reducing mortality in animal study and improving neurologic outcome in patients with traumatic brain injury. However, therapeutic hypothermia for pediatric traumatic brain injury remains a controversial issue. To determine the effectiveness and safety of hypothermia treatment for pediatric traumatic brain injury patients, we conducted this meta-analysis.

PATIENTS AND METHODS

We analyzed the data from MEDLINE, Pubmed, EMBASE, and Cochrane Library by electronic searching. No limitation of language was selected for analysis. We extracted the mortality and adverse events from the published trials.

RESULTS

Six clinical trials and 366 pediatric patients met our inclusion criteria. Pediatric patients with traumatic brain injury treated with hypothermia had more unfavorable outcome than those in the normothermia group (RR 1.73, 95 % CI 1.06 to 2.84), and this increased risk is statistically significant. Patients with therapeutic hypothermia are slightly likely to be induced by cardiac arrhythmia, and the likelihood is also significant (RR 2.57, 95 % CI 1.01 to 6.54). Risk of pneumonia has no statistical difference between normothermia and hypothermia arms (RR 0.90, 95 % CI 0.73 to 1.12). Two of the included trials have reported their detail randomization assignment.

CONCLUSIONS

Hypothermia may slightly increase the risk of mortality in children with traumatic brain injury and the ratio of cardiac arrhythmia after this hypothermia therapy is slightly higher than that in normothermia groups. In the future, more randomized controlled trials and multicenter studies on the mechanism of therapeutic hypothermia are required.

Risk factors for mortality in children with abusive head trauma

OBJECTIVE

We sought to identify risk factors for mortality in a large clinical cohort of children with abusive head trauma.

STUDY DESIGN

Bivariate analysis and multivariable logistic regression models identified demographic, physical examination, and radiologic findings associated with in-hospital mortality of children with abusive head trauma at 4 pediatric centers. An initial Glasgow Coma Scale (GCS) ≤ 8 defined severe abusive head trauma. Data are shown as OR (95% CI).

RESULTS

Analysis included 386 children with abusive head trauma. Multivariable analysis showed children with initial GCS either 3 or 4-5 had increased mortality vs children with GCS 12-15 (OR = 57.8; 95% CI, 12.1-277.6 and OR = 15.6; 95% CI, 2.6-95.1, respectively, P < .001). Additionally, retinal hemorrhage (RH), intraparenchymal hemorrhage, and cerebral edema were independently associated with mortality. In the subgroup with severe abusive head trauma and RH (n = 117), cerebral edema and initial GCS of 3 or 4-5 were independently associated with mortality. Chronic subdural hematoma was independently associated with survival.

CONCLUSIONS

Low initial GCS score, RH, intraparenchymal hemorrhage, and cerebral edema are independently associated with mortality in abusive head trauma. Knowledge of these risk factors may enable researchers and clinicians to improve the care of these vulnerable children.

[Death due to (no) airway. Adverse events by out-of-hospital airway management?]

Securing the airway is a rarely performed procedure in the out-of-hospital setting. In recent years evidence has been accumulated indicating that out-of-hospital airway management is more challenging as compared to elective situations even for experienced health care providers. Furthermore, several authors have questioned the benefit of out-of-hospital tracheal intubation. This review argues the problems regarding out-of-hospital airway management studies and discusses potential solutions which may improve out-of-hospital health care.

Impact of hypotension and low cerebral perfusion pressure on outcomes in children treated with hypothermia therapy following severe traumatic brain injury: a post hoc analysis of the Hypothermia Pediatric Head Injury Trial

Hypotension and low cerebral perfusion pressure are known to be associated with unfavorable outcome in children and adults with traumatic brain injury. Using the database from a previously published, randomized controlled trial of 24 h of hypothermia therapy in children with severe traumatic brain injury, we compared the number of patients with hypotension or low cerebral perfusion pressure between the hypothermia therapy and normothermia groups. We also determined the association between these physiologic insults and unfavorable outcome using regression analysis. There were more patients with episodes of hypotension or low cerebral perfusion pressure in the hypothermia therapy group than in the normothermia group. These physiologic insults were associated with unfavorable outcome in both intervention groups. Hypotension and low cerebral perfusion pressure should be anticipated and prevented in future trials of hypothermia therapy in patients with traumatic brain injury.

Emergency tracheal intubation of severely head-injured children: changing daily practice after implementation of national guidelines

OBJECTIVE

To report daily practice of scene emergency tracheal intubation performed by physicians and changes induced by implementation of national guidelines, with special attention to rapid sequence induction (RSI) and control of assisted ventilation.

DESIGN

Observational study.

SETTING

Pediatric intensive care unit of a university hospital.

PATIENTS

A total of 296 children (age, 2-15 yrs old) referred to our center for severe traumatic brain injury (Glasgow Coma Scale score of ≤ 8), with spontaneous cardiac rhythm.

INTERVENTIONS

Scene RSI practice by field physicians was compared before (n = 188), and after (n = 108) publication of national guidelines. Emergency tracheal intubation conditions, RSI use, immediate complications, assisted ventilation efficiency on blood gases measurements upon arrival, and, in the later period, physician's knowledge, and observance to published guidelines were analyzed.

MEASUREMENTS AND MAIN RESULTS

After publication of guidelines, tracheal intubation was performed at the scene in 100% of the cases (vs. 88%, p = .05); RSI practice was more standardized, with an increased use of succinylcholine (10% to 80%, p = .0001), and a concomitant decreased use of nondepolarizing muscle relaxant (20% vs. 0%, p = .005), and opioids (70% vs. 36%, p = .05). Recommended RSI protocol (etomidate and succinylcholine) was effectively used by 64% of the physicians (vs. 2.8%, p = .001), and rate of immediate complications upon tube insertion (mainly cough reflex) decreased to 8% (vs. 25%, p = .0015). Scene emergency tracheal intubation, when ordered, resulted in a 100% success rate and adequate oxygenation within the two groups. Despite increasing the use of portable capnograph in the later period, Paco2 was measured outside the tight target range (35-40 torr, 4.6-5.3 kPa) in 70% of the cases upon arrival.

CONCLUSIONS

Scene emergency tracheal intubation was effectively performed by trained careproviders in children with traumatic brain injury. Implementation of guidelines led to a more standardized practice of RSI, decreased rate of immediate complications, but insufficient control of Paco2 during transport.

Use and effect of vasopressors after pediatric traumatic brain injury

BACKGROUND

Vasopressors are commonly used to increase mean arterial blood pressure (MAP) and cerebral perfusion pressure (CPP) after traumatic brain injury (TBI), but there are few data comparing vasopressor effectiveness after pediatric TBI.

OBJECTIVE

To determine which vasopressor is most effective at increasing MAP and CPP in children with moderate-to-severe TBI.

METHODS

After institutional review board approval, we performed a retrospective cohort study of children 0-17 years old admitted to a level 1 trauma center (Harborview Medical Center, Seattle, Wash., USA) between 2002 and 2007 with moderate-to-severe TBI who received a vasopressor to increase blood pressure. Baseline demographic and physiologic characteristics and hourly physiologic monitoring for 3 h after having started a vasopressor were abstracted. We evaluated differences in MAP and CPP at 3 h after initiation of therapy between phenylephrine, dopamine and norepinephrine among patients who did not require a second vasopressor during this time. Multivariate linear regression was used to adjust for age, gender, injury severity score and baseline MAP or CPP and to cluster by subject.

RESULTS

Eighty-two patients contributed data to the entire dataset. The most common initial medication was phenylephrine for 47 (57%). Patients receiving phenylephrine and norepinephrine tended to be older than those receiving dopamine and epinephrine. Thirteen (16%) of the patients received a second vasopressor during the first 3 h of treatment and were thus not included in the regression analyses; these patients received more fluid resuscitation and exhibited higher in-hospital mortality (77 vs. 32%; p = 0.004) compared to patients receiving a single vasopressor. The norepinephrine group exhibited a 5 mm Hg higher MAP (95% CI: -4 to 13; p = 0.31) and a 12 mm Hg higher CPP (95% CI: -2 to 26; p = 0.10) than the phenylephrine group, and a 5 mm Hg higher MAP (95% CI: -4 to 15; p = 0.27) and a 10 mm Hg higher CPP (95% CI: -5 to 25; p = 0.18) than the dopamine group. However, in post hoc analysis, after adjusting for time to start of vasopressor, hypertonic saline and pentobarbital, the effect on MAP was lost, but the CPP was 8 mm Hg higher (95% CI: -10 to 25; p = 0.39) than in the phenylephrine group, and 5 mm Hg higher (95% CI: -14 to 24; p = 0.59) than in the dopamine group.

CONCLUSIONS

Vasopressor use varied by age. While there was no statistically significant difference in MAP or CPP between vasopressor groups, norepinephrine was associated with a clinically relevant higher CPP and lower intracranial pressure at 3 h after start of vasopressor therapy compared to the other vasopressors examined.

Fluid resuscitation with isotonic or hypertonic saline solution avoids intraneural calcium influx after traumatic brain injury associated with hemorrhagic shock

BACKGROUND

Calcium is one of the triggers involved in ischemic neuronal death. Because hypotension is a strong predictor of outcome in traumatic brain injury (TBI), we tested the hypothesis that early fluid resuscitation blunts calcium influx in hemorrhagic shock associated to TBI.

METHODS

Fifteen ketamine-halothane anesthetized mongrel dogs (18.7 kg +/- 1.4 kg) underwent unilateral cryogenic brain injury. Blood was shed in 5 minutes to a target mean arterial pressure of 40 mm Hg to 45 mm Hg and maintained at these levels for 20 minutes (shed blood volume = 26 mL/kg +/- 7 mL/kg). Animals were then randomized into three groups: CT (controls, no fluid resuscitation), HS (7.5% NaCl, 4 mL/kg, in 5 minutes), and LR (lactate Ringer's, 33 mL/kg, in 15 minutes). Twenty minutes later, a craniotomy was performed and cerebral biopsies were obtained next to the lesion ("clinical penumbra") and from the corresponding contralateral side ("lesion's mirror") to determine intracellular calcium by fluorescence signals of Fura-2-loaded cells.

RESULTS

Controls remained hypotensive and in a low-flow state, whereas fluid resuscitation improved hemodynamic profile. There was a significant increase in intracellular calcium in the injured hemisphere in CT (1035 nM +/- 782 nM), compared with both HS (457 nM +/- 149 nM, p = 0.028) and LR (392 nM +/- 178 nM, p = 0.017), with no differences between HS and LR (p = 0.38). Intracellular calcium at the contralateral, uninjured hemisphere was 438 nM +/- 192 nM in CT, 510 nM +/- 196 nM in HS, and 311 nM +/- 51 nM in LR, with no significant differences between them.

CONCLUSION

Both small volume hypertonic saline and large volume lactated Ringer's blunts calcium influx in early stages of TBI associated to hemorrhagic shock. No fluid resuscitation strategy promotes calcium influx and further neural damage.

Variation in cerebral blood flow velocity with cerebral perfusion pressure >40 mm Hg in 42 children with severe traumatic brain injury

OBJECTIVE

: To determine the prevalence of low, normal, and high mean middle cerebral artery flow velocity when cerebral perfusion pressure is >40 mm Hg in children with severe traumatic brain injury. There is no information regarding the relationship between middle cerebral artery flow velocity and cerebral perfusion pressure in pediatric traumatic brain injury.

DESIGN

: Prospective, observational study.

SETTING

: Level I pediatric trauma center.

PATIENTS

: A total of 42 children <17 yrs of age with an admission diagnosis of severe traumatic brain injury (admission Glasgow Coma Scale score of <9), traumatic brain injury on computed tomography scan, tracheal intubation/mechanical ventilation, and intracranial pressure monitoring.

INTERVENTIONS

: None.

MEASUREMENTS AND MAIN RESULTS

: Bilateral middle cerebral arteries were insonated using transcranial Doppler ultrasonography to calculate mean middle cerebral artery flow velocity after traumatic brain injury. Low mean middle cerebral artery flow velocity was defined as middle cerebral artery flow velocity <2 standard deviation and high was defined as mean middle cerebral artery flow velocity >2 standard deviation. Patients were grouped by age (0.8-2.9, 3-5.9, 6-9.9, and 10-16.9 yrs) and gender to examine the relationship between cerebral perfusion pressure and low, high, or normal mean middle cerebral artery flow velocity. Potential confounders of the relationship between cerebral perfusion pressure and mean middle cerebral artery flow velocity (intracranial pressure, PaCO2, hematocrit, sedation, fever,and impaired autoregulation were examined). Most children (n = 33; 79%) had normal mean middle cerebral artery flow velocity but four patients (9%) had low mean middle cerebral artery flow velocity and five children (12%) had high mean middle cerebral artery flow velocity despite cerebral perfusion pressure >40 mm Hg. There was no difference in potential confounders of the relationship between cerebral perfusion pressure and mean middle cerebral artery flow velocity except for hematocrit, which was lower (25 +/- 4%; range = 21-30%) in children with high mean middle cerebral artery flow velocity. An inverse relationship between mean middle cerebral artery flow velocity and hematocrit was also found in boys aged 10 to 16.9 yrs.

CONCLUSIONS

: Both low and/or high mean middle cerebral artery flow velocity occur with cerebral perfusion pressure >40 mm Hg in severe pediatric traumatic brain injury. Of the potential confounders considered, only lower hematocrit was associated with high mean middle cerebral artery flow velocity.

Blood pressure changes after intravenous fosphenytoin and levetiracetam in patients with acute cerebral symptoms

PURPOSE

To study the incidence and extent of the occasionally noted hypotension after intravenous (IV) infusions of fosphenytoin (FOS) and levetiracetam (LEV) in patients presenting with acute cerebral symptoms.

METHODS

Retrospective data collection of consecutive patients with acute cerebral symptoms who received IV infusions of a single dose of 750 mg or more of either fosphenytoin or levetiracetam and had documented blood pressure values in the 2h prior and the 2h after their IV infusion.

RESULTS

More than 10 mmHg drop in the systolic, diastolic and MBP was observed in the FOS group following the IV infusion (-16.82 mmHg, -11.60 mmHg, and 13.34 mmHg, respectively). However, there was not a significant change in the MBP after LEV infusion (1.54 mmHg, 1.84 mmHg, and 1.74 mmHg for systolic, diastolic and MBP change, respectively). The difference in the systolic, diastolic and MBP changes between the two groups was statistical significant (all p values are <0.0001) after adjusting for age, clinical presentations of the patients and if they were on any antihypertensive medication in the hospital. Sixty two percent of patients who received FOS had >10 mmHg decrease in their MBP. In the LEV group, only 2 of the 50 patients (4%) had >10 mmHg decrease in their MBP. The difference in proportion of the patients with >10 mmHg drop in MBP between the two study groups is also statistically significant (p<0.001) for age, clinical presentations of the patients and if they were on any antihypertensive medication in the hospital.

CONCLUSIONS

IV infusion of FOS in subjects presenting with acute cerebral symptoms may cause significant decreases in their blood pressure. This was not seen in patients receiving IV LEV infusions. Since maintaining adequate cerebral perfusion pressure is a key point in the management of patients with acute cerebral symptoms, the results of this study may carry a clinical impact on the management of this subgroup of patients.

Early prediction of posttraumatic in-hospital mortality in pediatric patients

BACKGROUND

The purpose of this study was to develop a triaging tool to predict pediatric in-hospital mortality from data available soon after emergency department (ED) presentation.

METHODS

The study group consisted of patients of less than 18 years of age from the National Trauma Data Bank with a reported in-hospital mortality status. Variables analyzed were (1) patient demographics, (2) Glasgow Coma Scale (GCS) values, (3) ED vital signs, (4) injury mechanism, and (5) number of days from trauma until admission. Chi-square-assisted interaction detection (CHAID) profiled patient subgroups. The final cohort was randomly divided into 2 equal sets: a training set to subgroup patients and a testing set to validate the prediction accuracy.

RESULTS

The cohort consisted of 224,628 patients with 2.29% in-hospital mortality. Sixteen of 19 potential variables were associated with increased risk of in-hospital mortality. The relative risk of dying was 61.7 times greater (95% confidence interval 57.5-66.1) when CHAID predicted mortality relative to when the model predicted survival (P<0.0001). The most powerful variables of the CHAID model were low total GCS scores and systolic blood pressure in the ED. The CHAID model had an improved relative risk and a better combination of sensitivity and positive predictive value compared with GCS and systolic blood pressure in predicting mortality.

CONCLUSIONS

The risk of in-hospital mortality for injured children may be identified soon after arrival in the ED. This information may be used by frontline providers to appropriately triage patients to pediatric trauma centers quickly, to guide resuscitation, and for teaching purposes.

Cerebrovascular pathophysiology in pediatric traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) is the leading cause of traumatic morbidity and mortality in children. Although there is increasing information concerning TBI in adults and experimental animal models, relatively little is known regarding cerebrovascular pathophysiology specific to children.

MATERIALS

A review of the pertinent medical literature.

RESULTS

Systemic and cerebral hemodynamic factors such as hypotension, hypoxia, hyperglycemia, and fever are associated with poor outcome in pediatric TBI. Similarly, cerebral autoregulation is often impaired after TBI and may adversely affect outcome, especially if systemic hemodynamics are altered. Furthermore, CO2 vasoreactivity may be altered after pediatric TBI and lead to either cerebral ischemia or hyperemia.

CONCLUSIONS

Understanding the effect of pediatric TBI on the cerebral circulation is needed to potentially develop protocols to improve outcome in this vulnerable population. Specifically, changes in pediatric cerebrovascular physiology and pathophysiology, including CO2 vasoreactivity and pressure autoregulation, must be understood and their mechanism elucidated.

Cerebral hemodynamic predictors of poor 6-month Glasgow Outcome Score in severe pediatric traumatic brain injury

Little is known regarding the cerebral autoregulation in pediatric traumatic brain injury (TBI). We examined the relationship between cerebral hemodynamic predictors, including cerebral autoregulation, and long-term outcome after severe pediatric TBI. After Institutional Review Board (IRB) approval, a retrospective analysis of prospectively collected data (May 2002 to October 2007) for children age < or =16 years with severe TBI (admission Glasgow Coma Scale [GCS] score <9) was performed. Cerebral autoregulation was assessed within 72 h after TBI. Cerebral hemodynamic predictors (intracranial pressure [ICP], systolic blood pressure [SBP], and cerebral perfusion pressure [CPP]) through the first 72 h after TBI were abstracted. Univariate and multivariate analyses examined the relationship between impaired cerebral autoregulation (autoregulatory index <0.4), intracranial hypertension (ICP >20 mm Hg), and hypotension (SBP <5th percentile and CPP <40 mm Hg). Six-month Glasgow Outcome Scale (GOS) score of <4 defined poor outcome. Ten (28%) of the 36 children examined (9.1 +/- 5.3 [0.8-16] years; 74% male) had poor outcome. Univariate factors associated with poor outcome were impaired cerebral autoregulation (p = 0.005), SBP <5(th) percentile for age and gender (p = 0.02), and low middle cerebral artery flow velocity (<2 SD for age and gender; p = 0.04). Independent risk factors for poor 6-month GOS were impaired cerebral autoregulation (adjusted odds ratio [aOR] 12.0; 95% confidence interval [CI] 1.4-99.4) and hypotension (SBP <5th percentile; aOR 8.8; 95% CI 1.1-70.5), respectively. Previous studies of TBI describing poor outcome with hemodynamics did not consider the status of cerebral autoregulation. In this study, both impaired cerebral autoregulation and SBP <5th percentile were independent risk factors for poor 6-month GOS.

Early resuscitation of children with moderate-to-severe traumatic brain injury

OBJECTIVES

Traumatic brain injury is a leading cause of death and disability in children. Guidelines have been established to prevent secondary brain injury caused by hypotension or hypoxia. The purpose of this study was to identify the prevalence, monitoring, and treatment of hypotension and hypoxia during "early" (prehospital and emergency department) care and to evaluate their relationship to vital status and neurologic outcomes at hospital discharge.

METHODS

This was a retrospective study of 299 children with moderate-to-severe traumatic brain injury presenting to a level 1 pediatric trauma center. We recorded vital signs and medical provider response to hypotension and/or hypoxia during all portions of early care.

RESULTS

Blood pressure (31%) and oxygenation (34%) were not recorded during some portion of "early care." Documented hypotension occurred in 118 children (39%). An attempt to treat documented hypotension was made in 48% (57 of 118 children). After adjusting for severity of illness, children who did not receive an attempt to treat hypotension had an increased odds of death of 3.4 and were 3.7 times more likely to suffer disability compared with treated hypotensive children. Documented hypoxia occurred in 131 children (44%). An attempt to treat hypoxia was made in 92% (121 of 131 children). Untreated hypoxia was not significantly associated with death or disability, except in the setting of hypotension.

CONCLUSIONS

Hypotension and hypoxia are common events in pediatric traumatic brain injury. Approximately one third of children are not properly monitored in the early phases of their management. Attempts to treat hypotension and hypoxia significantly improved outcomes.

Prehospital management of traumatic brain injury

The aim of this study was to review the current protocols of prehospital practice and their impact on outcome in the management of traumatic brain injury. A literature review of the National Library of Medicine encompassing the years 1980 to May 2008 was performed. The primary impact of a head injury sets in motion a cascade of secondary events that can worsen neurological injury and outcome. The goals of care during prehospital triage, stabilization, and transport are to recognize life-threatening raised intracranial pressure and to circumvent cerebral herniation. In that process, prevention of secondary injury and secondary insults is a major determinant of both short- and longterm outcome. Management of brain oxygenation, blood pressure, cerebral perfusion pressure, and raised intracranial pressure in the prehospital setting are discussed. Patient outcomes are dependent upon an organized trauma response system. Dispatch and transport timing, field stabilization, modes of transport, and destination levels of care are addressed. In addition, special considerations for mass casualty and disaster planning are outlined and recommendations are made regarding early response efforts and the ethical impact of aggressive prehospital resuscitation. The most sophisticated of emergency, operative, or intensive care units cannot reverse damage that has been set in motion by suboptimal protocols of triage and resuscitation, either at the injury scene or en route to the hospital. The quality of prehospital care is a major determinant of long-term outcome for patients with traumatic brain injury.

Incidence and risk factors for preincision hypotension in a noncardiac pediatric surgical population

BACKGROUND

Routine monitoring of blood pressure is an essential part of perioperative care in adults and children. It is however not known whether intraoperative hypotension (IOH) is clinically important in the 'healthy' pediatric patient. This may be partly due to the lack of data on the incidence and consequences of IOH in this group of patients. We utilized the Brain Trauma Foundation definition of hypotension to describe the incidence of preincision hypotension (PIH) in a large pediatric noncardiac surgical population and identified risk factors for the occurrence PIH.

METHODS

We examined the electronic perioperative records of all children aged 1-17 years undergoing general anesthesia for noncardiac surgeries between January 2005 and June 2007 in our institution. Frequency and factors associated with PIH were computed. Binary logistic regression with forward step-wise algorithm was used to examine factors associated with PIH.

RESULTS

There were 22,263 children of whom 57.6% were males. Most (94.9%) cases were elective, American Society of Anesthesiologists (ASA) I-II (79.5%) procedures. Inhalational induction was predominantly used in this cohort (67%) although 33% of patients had propofol either as a sole induction agent or as part of a 'co-induction' regime. Single or multiple episodes of PIH occurred in 35.8% of patients. PIH was more common in patients with ASA > or = III (P < 0.001); those with preoperative hypotension (P < 0.001); and following intravenous induction (P < 0.001) as well as propofol co-induction (P < 0.001). On multivariate analysis the following were significant predictors of PIH: baseline hypotension, propofol co-induction, age, ASA > or = III, and long preincision period.

CONCLUSION

Preincision hypotension is common in the pediatric surgical population undergoing general anesthesia. Factors independently predictive of PIH included high ASA status, pre-existing hypotension, propofol co-induction prolonged preincision period and adolescent age group. The importance of blood pressure monitoring, prompt recognition of hypotension and use of appropriate intervention is emphasized.

Does adherence to treatment targets in children with severe traumatic brain injury avoid brain hypoxia? A brain tissue oxygenation study

OBJECTIVE

Most physicians rely on conventional treatment targets for intracranial pressure, cerebral perfusion pressure, systemic oxygenation, and hemoglobin to direct management of traumatic brain injury (TBI) in children. In this study, we used brain tissue oxygen tension (PbtO2) monitoring to examine the association between PbtO2 values and outcome in pediatric severe TBI and to determine the incidence of compromised PbtO2 in patients for whom acceptable treatment targets had been achieved.

METHODS

In this prospective observational study, 26 children with severe TBI and a median postresuscitation Glasgow Coma Scale score of 5 were managed with continuous PbtO2 monitoring. The relationships between outcome and the 6-hour period of lowest PbtO2 values and the length of time that PbtO2 was less than 20, 15, 10, and 5 mmHg were examined. The incidence of reduced PbtO2 for each threshold was evaluated where the following targets were met: intracranial pressure less than 20 mmHg, cerebral perfusion pressure greater than 50 mmHg, arterial oxygen tension greater than 60 mmHg (and peripheral oxygen saturation > 90%), and hemoglobin greater than 8 g/dl.

RESULTS

There was a significant association between poor outcome and the 6-hour period of lowest PbtO2 and length of time that PbtO2 was less than 15 and 10 mmHg. Multiple logistic regression analysis showed that low PbtO2 had an independent association with poor outcome. Despite achieving the management targets described above, 80% of patients experienced one or more episodes of compromised PbtO2 (< 20 mmHg), and almost one-third experienced episodes of brain hypoxia (PbtO2 < 10 mmHg).

CONCLUSION

Reduced PbtO2 is associated with poor outcome in pediatric severe TBI. In addition, many patients experience episodes of compromised PbtO2 despite achieving acceptable treatment targets.

Management of critically ill children with traumatic brain injury

The management of critically ill children with traumatic brain injury (TBI) requires a precise assessment of the brain lesions but also of potentially associated extra-cranial injuries. Children with severe TBI should be treated in a pediatric trauma center, if possible. Initial assessment relies mainly upon clinical examination, trans-cranial Doppler ultrasonography and body CT scan. Neurosurgical operations are rarely necessary in these patients, except in the case of a compressive subdural or epidural hematoma. On the other hand, one of the major goals of resuscitation in these children is aimed at protecting against secondary brain insults (SBI). SBI are mainly because of systemic hypotension, hypoxia, hypercarbia, anemia and hyperglycemia. Cerebral perfusion pressure (CPP = mean arterial blood pressure - intracranial pressure: ICP) should be monitored and optimized as soon as possible, taking into account age-related differences in optimal CPP goals. Different general maneuvers must be applied in these patients early during their treatment (control of fever, avoidance of jugular venous outflow obstruction, maintenance of adequate arterial oxygenation, normocarbia, sedation-analgesia and normovolemia). In the case of increased ICP and/or decreased CPP, first-tier ICP-specific treatments may be implemented, including cerebrospinal fluid drainage, if possible, osmotic therapy and moderate hyperventilation. In the case of refractory intracranial hypertension, second-tier therapy (profound hyperventilation with P(a)CO(2) < 35 mmHg, high-dose barbiturates, moderate hypothermia, decompressive craniectomy) may be introduced, after a new cerebral CT scan.

Cerebral blood flow and autoregulation after pediatric traumatic brain injury

Traumatic brain injury is a global health concern and is the leading cause of traumatic morbidity and mortality in children. Despite a lower overall mortality than in adult traumatic brain injury, the cost to society from the sequelae of pediatric traumatic brain injury is very high. Predictors of poor outcome after traumatic brain injury include altered systemic and cerebral physiology, including altered cerebral hemodynamics. Cerebral autoregulation is often impaired after traumatic brain injury and may adversely impact the outcome. Although altered cerebrovascular hemodynamics early after traumatic brain injury may contribute to disability in children, there is little information regarding changes in cerebral blood flow and cerebral autoregulation after pediatric traumatic brain injury. This review addresses normal pediatric cerebral physiology and cerebrovascular pathophysiology after pediatric traumatic brain injury.