Glycemia Is Related to Impaired Cerebrovascular Autoregulation after Severe Pediatric Traumatic Brain Injury: A Retrospective Observational Study

Abstract

IntroductionA strong association exists between hyperglycemia and outcome in pediatric traumatic brain injury (TBI). Herein, we describe observations of serum markers of glucose metabolism in a cohort of pediatric TBI patients and how these variables are related to parameters of intracranial pathophysiology.MethodsA retrospective analysis was performed on pediatric severe TBI patients admitted to Addenbrookes Hospital Paediatric Intensive Care Unit (PICU) between January 2001 and December 2013. Demographic, outcome, systemic physiological, and cerebral autoregulatory data were extracted for patients who had received continuous invasive monitoring (ICM+, Cambridge Enterprise, Cambridge, UK). Data were analyzed using a mixed linear model.ResultsForty-four patients with an average age of 12.2 years were admitted to the PICU with a TBI requiring invasive neurosurgical monitoring. Thirty-two patients (73%) survived, with favorable outcomes in 62%. The mean (SD) intracranial pressure (ICP) was 17.6 + 9.0 mmHg, MAP was 89.7 + 9.0 mmHg, and pressure-reactivity index (PRx) was −0.01 + 0.23 a.u. The mean (SD) serum lactate was 2.2 (3.3) mmol/L. and the mean (SD) serum glucose was 6.1 (1.6) mmol/L. Early hyperglycemia was strongly associated with both PRx (Pearson correlation 0.351, p < 0.001) and ICP (Pearson correlation 0.240, p = 0.002) death (p = 0.021) and impaired cerebral autoregulation (p = 0.02). There was a strong association between ICP and serum lactate (p = 0.001).ConclusionIncreases in systemic glucose are associated with impaired cerebrovasular autoregulation after severe pediatric TBI. Moreover, deranged blood glucose is a marker of poor prognosis. Further studies are required to delineate putative mechanisms of hyperglycemia induced cerebral harm.

High Arterial Glucose is Associated with Poor Pressure Autoregulation, High Cerebral Lactate/Pyruvate Ratio and Poor Outcome Following Traumatic Brain Injury

“…In line with prior studies [13, 22], we found high arterial glucose to be associated with poor outcome (Table 4). As the mean daily arterial glucose decreased from days 1 to 3, the association between arterial glucose and outcome decreased in a similar way.…”

“…The pathophysiology of high arterial glucose in TBI is not fully elucidated; however, according to preclinical studies, arterial hyperglycemia decreases blood flow in systemic and cerebral blood vessels and causes endothelial dysfunction, indicating a link with failed cerebral autoregulation [4–7]. Two clinical studies have shown a weak, significant correlation between pressure autoregulation and arterial glucose in adult and pediatric TBI, respectively [12, 13], consistent with our results in the current study.…”

“…In a recent clinical study by Donnelly et al, PRx had a positive, significant correlation with arterial glucose after TBI [12]. Young et al had similar findings in a pediatric TBI population [13]. However, the interaction between arterial glucose, PRx, and cerebral energy metabolism has not been elucidated.…”

Cerebral Autoregulation-guided Management of Adult and Pediatric Traumatic Brain Injury

“…Impaired CA is observed after a concussion, 12,13 diffuse TBI, 14 during the progression of TBI lesions, 15 and during the progression of cerebral edema. 15,16 In addition, APACHE II score, 17 leukocytosis, 18 high arterial lactate, 19 and hyperglycemia 20,21 are associated with impaired CA. Variables that have been tested for association with CA and clinical outcomes after TBI are shown in Table 2.…”