Cardiac-cerebral-renal associations in pediatric traumatic brain injury: Preliminary findings.

OBJECTIVE: The clinical epidemiology of organ outcomes in pediatric traumatic brain injury (TBI) has not been examined. We describe associated markers of cerebral, cardiac and renal injury after pediatric TBI. DESIGN: Prospective observational study. PATIENTS: Children 0-18 years who were hospitalized with TBI. MEASUREMENTS: Measures of myocardial (at least one elevated plasma troponin [cTnI] ≥ 0.4 ng/ml) and multiorgan (hemodynamic variables, cerebral perfusion, and renal) function were examined within the first ten days of hospital admission and within 24 h of each other. MAIN RESULTS: Data from 28 children who were 11[IQR 10.3] years, male (64.3%), with isolated TBI (67.9%), injury severity score (ISS) 25[10], and admission Glasgow coma score (GCS) 11[9] were examined. Overall, 50% (14 children) had elevated cTnI, including those with isolated TBI (57.9%; 11/19), polytrauma (33.3%; 3/9), mild TBI (57.1% 8/14), and severe TBI (42.9%; 6/11). Elevated cTnI occurred within the first six days of admission and across all age groups, in both sexes, and regardless of TBI lesion type, GCS, and ISS. Age-adjusted admission tachycardia was associated with cTnI elevation (AUC 0.82; p < 0.001). Reduced urine output occurred more commonly in patients with isolated TBI (27.3% elevated cTnI vs. 0% normal cTnI). CONCLUSIONS: Myocardial injury commonly occurs during the first six days after pediatric TBI irrespective of injury severity, age, sex, TBI lesion type, or polytrauma. Age-adjusted tachycardia may be a clinical indicator of myocardial injury, and elevated troponin may be associated with cardio-cerebro-renal dysfunction.

Plasma Levels, Temporal Trends and Clinical Associations between Biomarkers of Inflammation and Vascular Homeostasis after Pediatric Traumatic Brain Injury.

Expression of inflammatory (interleukin-6 [IL-6]) and vascular homeostatic (angiopoietin-2 [AP-2], endothelin-1 [ET-1], endocan-2 [EC-2]) biomarkers in pediatric traumatic brain injury (TBI) was examined in this prospective, observational cohort study of 28 children hospitalized with mild, moderate, and severe TBI by clinical measures (age, sex, Glasgow Coma Scale score [GCS], Injury Severity Score [ISS], and cerebral autoregulation status). Biomarker patterns suggest an inverse relationship between GCS and AP-2, GCS and IL-6, ISS and ET-1, but a direct relationship between GCS and ET-1 and ISS and AP-2. Biomarker patterns suggest an inverse relationship between AP-2 and ET-1, AP-2 and EC-2, but a direct relationship between AP-2 and IL-6, IL-6 and EC-2, and IL-6 and ET-1. Plasma concentrations of inflammatory and vascular homeostatic biomarkers suggest a role for inflammation and disruption of vascular homeostasis during the first 10 days across the severity spectrum of pediatric TBI. Although not statistically significant, without impact on cerebral autoregulation, biomarker patterns suggest a relationship between inflammation and alterations in vascular homeostasis. The large variation in biomarker levels within TBI severity and age groups, and by sex suggests other contributory factors to biomarker expression.

Prevalence, Evolution, and Extent of Impaired Cerebral Autoregulation in Children Hospitalized With Complex Mild Traumatic Brain Injury.

OBJECTIVES: To examine cerebral autoregulation in children with complex mild traumatic brain injury. DESIGN: Prospective observational convenience sample. SETTING: PICU at a level I trauma center. PATIENTS: Children with complex mild traumatic brain injury (trauma, admission Glasgow Coma Scale score 13-15 with either abnormal head CT, or history of loss of consciousness). INTERVENTIONS: Cerebral autoregulation was tested using transcranial Doppler ultrasound between admission day 1 and 8. MEASUREMENTS AND MAIN RESULTS: The primary outcome was prevalence of impaired cerebral autoregulation (autoregulation index < 0.4),determined using transcranial Doppler ultrasonography and tilt testing. Secondary outcomes examined factors associated with and evolution and extent of impairment. Cerebral autoregulation testing occurred in 31 children 10 years (SD, 5.2 yr), mostly male (59%) with isolated traumatic brain injury (91%), median admission Glasgow Coma Scale 15, Injury Severity Scores 14.2 (SD, 7.7), traumatic brain injury due to fall (50%), preadmission loss of consciousness (48%), and abnormal head CT scan (97%). Thirty-one children underwent 56 autoregulation tests. Impaired cerebral autoregulation occurred in 15 children (48.4%) who underwent 19 tests; 68% and 32% of tests demonstrated unilateral and bilateral impairment, respectively. Compared with children on median day 6 of admission after traumatic brain injury, impaired autoregulation was most common in the first 5 days after traumatic brain injury (day 1: relative risk, 3.7; 95% CI, 1.9-7.3 vs day 2: relative risk, 2.7; 95% CI, 1.1-6.5 vs day 5: relative risk, 1.33; 95% CI, 0.7-2.3). Children with impaired autoregulation were older (12.3 yr [SD, 1.3 yr] vs 8.7 yr [SD, 1.1 yr]; p = 0.04) and tended to have subdural hematoma (64% vs 44%), epidural hematoma (29% vs 17%), and subarachnoid hemorrhage (36% vs 28%). Eight children (53%) were discharged home with ongoing impaired cerebral autoregulation. CONCLUSIONS: Impaired cerebral autoregulation is common in children with complex mild traumatic brain injury, despite reassuring admission Glasgow Coma Scale 13-15. Children with complex mild traumatic brain injury have abnormal cerebrovascular hemodynamics, mostly during the first 5 days. Impairment commonly extends to the contralateral hemisphere and discharge of children with ongoing impaired cerebral autoregulation is common.