Energy Expenditure in Children After Severe Traumatic Brain Injury

Abstract

Objective To evaluate energy expenditure in a cohort of children with severe traumatic brain injury (TBI). Design A prospective observational study. Setting A pediatric neurotrauma center within a tertiary care institution. Patients Mechanically-ventilated children admitted with severe traumatic brain injury (GCS<9) with a weight greater than 10 kg were eligible for study. A subset of children was co-enrolled in a phase 3 study of early, therapeutic hypothermia. All children were treated with a comprehensive neurotrauma protocol that included sedation, neuromuscular blockade, temperature control, anti-seizure prophylaxis and a tiered-based system for treating intracranial hypertension. Interventions Within the first week after injury, indirect calorimetry measurements were performed daily when the patient’s condition permitted. Measurements and Main Results Data from 13 children were analyzed (with a total of 32 assessments). Measured energy expenditure (MEE) obtained from indirect calorimetry was compared to resting energy expenditure (pREE) calculated from Harris-Benedict equation. Overall, MEE/pREE averaged 70.2 ± 3.8%. Seven measurements obtained while children were hypothermic did not differ from normothermic values (75 ± 4.5% vs. 68.9 ± 4.7% respectively, p = 0.273). Moreover, children with favorable neurologic outcome at 6 months did not differ from children with unfavorable outcome (76.4 ± 6% vs. 64.7 ± 4.7% for the unfavorable outcome, p = 0.13). Conclusions Contrary to previous work from several decades ago that suggested severe pediatric TBI is associated with a hypermetabolic response (MEE/pREE > 110%); our data suggest that contemporary neurocritical care practices may blunt such a response. Understanding the metabolic requirements of children with severe TBI is the first step in development of rational nutritional support goals that might lead to improvements in outcome.

An Exploratory Retrospective Study of Factors Affecting Energy Expenditure in Critically Ill Children

“…In the small sample of patients with repeated measurements, MEE was almost unchanged between days, similar to reports by de Klerk and colleagues . A possible explanation is blunting of the initial expected elevation in energy expenditure by modern critical care therapies as has been reported in patients with traumatic brain injury . Another, is the delay in obtaining the initial measurement preventing the detection of changes between measurements.…”

Nutrition Delivery Affects Outcomes in Pediatric Acute Respiratory Distress Syndrome

“…In patients who received adequate protein, PICU mortality was also lower compared with those who did not receive adequate proteins (14.3% vs 60.2%, P = .002) ( Table 4). VFDs were significantly higher in patients who received adequate protein compared with patients who did not (12.0 [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] vs 0 [0-4], P = .005).…”

“…[9][10][11] Other patient groups with traumatic brain injury and post-cardiac surgery may exhibit hypometabolic responses. 12,13 To our knowledge, no studies have evaluated the energy expenditure in children with ARDS.…”

Indirect Calorimetry: History, Technology, and Application

“…Those developed to estimate energy expenditure in healthy children and extrapolated to use in the critically ill have been reported to be inaccurate in different populations, and their detailed review is out of the scope of this manuscript (6, 64–67). However, two equations have been derived for use in critically ill children: White and Meyer (68, 69).…”