Platelet Bioenergetics and Associations With Delirium and Coma in Patients With Sepsis: A Prospective Cohort Study.

BACKGROUND: Acute brain dysfunction during sepsis, which manifests as delirium or coma, is common and is associated with multiple adverse outcomes, including longer periods of mechanical ventilation, prolonged hospital stays, and increased mortality. Delirium and coma during sepsis may be manifestations of alteration in systemic metabolism. Because access to brain mitochondria is a limiting factor, measurement of peripheral platelet bioenergetics offers a potential opportunity to understand metabolic changes associated with acute brain dysfunction during sepsis. RESEARCH QUESTION: Are altered platelet mitochondrial bioenergetics associated with acute brain dysfunction during sepsis? STUDY DESIGN AND METHODS: We assessed participants with critical illness in the ICU for the presence of delirium or coma via validated assessment measures. Blood samples were collected and processed to isolate and measure platelet mitochondrial oxygen consumption. We used Seahorse extracellular flux to measure directly baseline, proton leak, maximal oxygen consumption rate, and extracellular acidification rate. We calculated adenosine triphosphate-linked, spare respiratory capacity, and nonmitochondrial oxygen consumption rate from the measured values. RESULTS: Maximum oxygen consumption was highest in patients with coma, as was spare respiratory capacity and extracellular acidification rate in unadjusted analysis. After adjusting for age, sedation, modified Sequential Organ Failure Assessment score without the neurologic component, and preexisting cognitive function, increased spare respiratory capacity remained associated with coma. Delirium was not associated with any platelet mitochondrial bioenergetics. INTERPRETATION: In this single-center exploratory prospective cohort study, we found that increased platelet mitochondrial spare respiratory capacity was associated with coma in patients with sepsis. Future studies powered to determine any relationship between delirium and mitochondrial respiration bioenergetics are needed.

Hepatic Encephalopathy in Children With Acute Liver Failure: Utility of Serum Neuromarkers.

BACKGROUND: Pediatric acute liver failure (PALF) is a public heath burden, often requiring prolonged hospitalization and liver transplantation. Hepatic encephalopathy (HE) is a complication of PALF with limited diagnostic tools to predict outcomes. Serum neurological markers (neuron-specific enolase, S100ß, and myelin basic protein) can be elevated in traumatic or ischemic brain injury. We hypothesized that these neuromarkers would be associated with the development of HE in PALF. METHODS: PALF study participants enrolled between May 2012 and December 2014 by 12 participating centers were the subjects of this analysis. Daily HE assessments were determined by study investigators. Neurological and inflammatory markers were measured using enzyme-linked immunosorbent assay and MILLIPLEX techniques, respectively. To model encephalopathy, these markers were log2 transformed and individually examined for association with HE using a generalized linear mixed model with a logit link and random intercept. RESULTS: Eighty-two children had neurological and inflammatory marker levels and HE assessments recorded, with the majority having assessments for 3 days during their illness. An indeterminate diagnosis (29%) was most common and the median age was 2.9 years. Significant associations were observed for HE with S100ß (odds ratio 1.16, 95% confidence interval [1.03-1.29], P = 0.04) and IL-6 (odds ratio 1.24 [1.11-1.38], P = 0.006). CONCLUSIONS: Serum S100ß and IL-6 are associated with HE in children with PALF. Measuring these markers may assist in assessing neurological injury in PALF, impacting clinical decisions.

The Diagnostic Yield of Malignancy Comparing Cytology, FISH, and Molecular Analysis of Cell Free Cytology Brush Supernatant in Patients With Biliary Strictures Undergoing Endoscopic Retrograde Cholangiography (ERC): A Prospective Study.

BACKGROUND: Routine cytology of biliary stricture brushings obtained during endoscopic retrograde cholangiopancreatography (ERCP) has suboptimal sensitivity for malignancy. We compared the individual and combined ability of cytology, fluorescence in situ hybridization (FISH) analysis and PCR-based mutation profiling (MP) to detect malignancy in standard biliary brushings. METHODS: We performed a prospective study of patients undergoing ERCP using histology or 1 year follow-up to determine patient outcomes. MP was performed on free-DNA from biliary brushing specimens using normally discarded supernatant fluid. MP examined KRAS point mutations and tumor suppressor gene associated loss of heterozygosity mutations at 10 genomic loci. FISH examined chromosome specific gains or losses. RESULTS: A total of 101 patients were included in final analysis and 69% had malignancy. Cytology had 26% sensitivity and 100% specificity for malignancy. Using either FISH or MP in combination with cytology increased sensitivity to 44% and 56%, respectively. The combination of all 3 tests (cytology, FISH, and MP) had the highest sensitivity for malignancy (66%). There was no difference in the specificity of cytology, FISH or MP testing when examined alone or in combination. MP improved diagnostic yield of each procedure from 22% to 100%; FISH improved yield to 90%. MP detected 21 malignancies beyond that identified by cytology; FISH detected an additional 13. The combination of FISH and MP testing detected an additional 28 malignancies. CONCLUSIONS: Both MP and FISH are complimentary molecular tests that can significantly increase detection of biliary malignancies when used in combination with routine cytology of standard biliary brush specimens.

Energy expenditure in children after severe traumatic brain injury.

OBJECTIVE: To evaluate energy expenditure in a cohort of children with severe traumatic brain injury. 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 (Glasgow Coma Scale < 9) with a weight more 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, antiseizure 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 obtained from indirect calorimetry was compared with predicted resting energy expenditure calculated from Harris-Benedict equation. Overall, measured energy expenditure/predicted resting energy expenditure 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). Furthermore, 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 traumatic brain injury is associated with a hypermetabolic response (measured energy expenditure/predicted resting energy expenditure > 110%), our data suggest that contemporary neurocritical care practices may blunt such a response. Understanding the metabolic requirements of children with severe traumatic brain injury is the first step in development of rational nutritional support goals that might lead to improvements in outcome.