Dataset Information

24-Hour protein, arginine and citrulline metabolism in fed critically ill children - A stable isotope tracer study.

ABSTRACT: The reference method to study protein and arginine metabolism in critically ill children is measuring plasma amino acid appearances with stable isotopes during a short (4-8 h) time period and extrapolate results to 24-h. However, 24-h measurements may be variable due to critical illness related factors and a circadian rhythm could be present. Since only short duration stable isotope studies in critically ill children have been conducted before, the aim of this study was to investigate 24-h appearance of specific amino acids representing protein and arginine metabolism, with stable isotope techniques in continuously fed critically ill children.In eight critically ill children, admitted to the pediatric (n = 4) or cardiovascular (n = 4) intensive care unit, aged 0-10 years, receiving continuous (par)enteral nutrition with protein intake 1.0-3.7 g/kg/day, a 24-h stable isotope tracer protocol was carried out. L-[ring-2H5]-phenylalanine, L-[3,3-2H2]-tyrosine, L-[5,5,5-2H3]-leucine, L-[guanido-15N2]-arginine and L-[5-13C-3,3,4,4-2H4]-citrulline were infused intravenously and L-[15N]-phenylalanine and L-[1-13C]leucine enterally. Arterial blood was sampled every hour.Coefficients of variation, representing intra-individual variability, of the amino acid appearances of phenylalanine, tyrosine, leucine, arginine and citrulline were high, on average 14-19% for intravenous tracers and 23-26% for enteral tracers. No evident circadian rhythm was present. The pattern and overall 24-h level of whole body protein balance differed per individual.In continuously fed stable critically ill children, the amino acid appearances of phenylalanine, tyrosine, leucine, arginine and citrulline show high variability. This should be kept in mind when performing stable isotope studies in this population. There was no apparent circadian rhythm.NCT01511354 on clinicaltrials.gov.

SUBMITTER: de Betue CTI

PROVIDER: S-EPMC5404980 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

24-Hour protein, arginine and citrulline metabolism in fed critically ill children - A stable isotope tracer study.

de Betue Carlijn T I CTI Garcia Casal Xiomara C XC van Waardenburg Dick A DA Schexnayder Stephen M SM Joosten Koen F M KFM Deutz Nicolaas E P NEP Engelen Marielle P K J MPKJ

Clinical nutrition (Edinburgh, Scotland) 20170104 3

<h4>Background & aims</h4>The reference method to study protein and arginine metabolism in critically ill children is measuring plasma amino acid appearances with stable isotopes during a short (4-8 h) time period and extrapolate results to 24-h. However, 24-h measurements may be variable due to critical illness related factors and a circadian rhythm could be present. Since only short duration stable isotope studies in critically ill children have been conducted before, the aim of this study was ...[more]

PMID: 28089618

Similar Datasets

Project description:BackgroundDetermining kidney function in critically ill patients is paramount for the dose adjustment of several medications. When assessing kidney function, the glomerular filtration rate (GFR) is generally estimated either by calculating urine creatinine clearance (UCrCl) or using a predictive equation. Unfortunately, all predictive equations have been derived for medical outpatients. Therefore, the validity of predictive equations is of concern when compared with that of the UCrCl method, particularly in medical critically ill patients. Therefore, we conducted this study to assess the agreement of the estimated GFR (eGFR) using common predictive equations and UCrCl in medical critical care setting.MethodsThis was the secondary analysis of a nutrition therapy study. Urine was collected from participating patients over 24 h for urine creatinine, urine nitrogen, urine volume, and serum creatinine measurements on days 1, 3, 5, and 14 of the study. Subsequently, we calculated UCrCl and eGFR using four predictive equations, the Cockcroft-Gault (CG) formula, the four and six-variable Modification of Diet in Renal Disease Study (MDRD-4 and MDRD-6) equations, and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. The correlation and agreement between eGFR and UCrCl were determined using the Spearman rank correlation coefficient and Bland-Altman plot with multiple measurements per subject, respectively. The performance of each predictive equation for estimating GFR was reported as bias, precision, and absolute percentage error (APE).ResultsA total of 49 patients with 170 urine samples were included in the final analysis. Of 49 patients, the median age was 74 (21-92) years-old and 49% was male. All patients were hemodynamically stable with mean arterial blood pressure of 82 (65-108) mmHg. Baseline serum creatinine was 0.93 (0.3-4.84) mg/dL and baseline UCrCl was 46.69 (3.40-165.53) mL/min. The eGFR from all the predictive equations showed modest correlation with UCrCl (r: 0.692 to 0.759). However, the performance of all the predictive equations in estimating GFR compared to that of UCrCl was poor, demonstrating bias ranged from -8.36 to -31.95 mL/min, precision ranged from 92.02 to 166.43 mL/min, and an unacceptable APE (23.01% to 47.18%). Nevertheless, the CG formula showed the best performance in estimating GFR, with a small bias (-2.30 (-9.46 to 4.86) mL/min) and an acceptable APE (14.72% (10.87% to 23.80%)), especially in patients with normal UCrCl.ConclusionFrom our finding, CG formula was the best eGFR formula in the medical critically ill patients, which demonstrated the least bias and acceptable APE, especially in normal UCrCl patients. However, the predictive equation commonly used to estimate GFR in critically ill patients must be cautiously applied due to its large bias, wide precision, and unacceptable error, particularly in renal function impairment.

Project description:BackgroundAcute kidney injury (AKI) is one of the most common complications for critically ill patients with cirrhosis, but it has remained unclear whether urine output fluctuations are associated with the risk of AKI in such patients. Thus, we explored the influence of 24-h urine-output trajectory on AKI in patients with cirrhosis through latent category trajectory modeling.Materials and methodsThis retrospective cohort study examined patients with cirrhosis using the MIMIC-IV database. Changes in the trajectories of urine output within 24 h after admission to the intensive care unit (ICU) were categorized using latent category trajectory modeling. The outcome examined was the occurrence of AKI during ICU hospitalization. The risk of AKI in patients with different trajectory classes was explored using the cumulative incidence function (CIF) and the Fine-Gray model with the sub-distribution hazard ratio (SHR) and the 95% confidence interval (CI) as size effects.ResultsThe study included 3,562 critically ill patients with cirrhosis, of which 2,467 (69.26%) developed AKI during ICU hospitalization. The 24-h urine-output trajectories were split into five classes (Classes 1-5). The CIF curves demonstrated that patients with continuously low urine output (Class 2), a rapid decline in urine output after initially high levels (Class 3), and urine output that decreased slowly and then stabilized at a lower level (Class 4) were at higher risk for AKI than those with consistently moderate urine output (Class 1). After fully adjusting for various confounders, Classes 2, 3, and 4 were associated with a higher risk of AKI compared with Class 1, and the respective SHRs (95% CIs) were 2.56 (1.87-3.51), 1.86 (1.34-2.59), and 1.83 1.29-2.59).ConclusionsThe 24-h urine-output trajectory is significantly associated with the risk of AKI in critically ill patients with cirrhosis. More attention should be paid to the dynamic nature of urine-output changes over time, which may help guide early intervention and improve patients' prognoses.

Project description:BackgroundKnowledge of the physiologic requirement for iron, the core index for the formulation of a dietary reference intake (DRI), is of great importance for the health of a pregnant woman and her fetus, and can help a mother accurately plan her iron supplementation. However, direct measurements of the physiologic requirement for iron during pregnancy are still lacking.MethodEleven women of reproductive age from Hebei Province, China, who planned to become pregnant in the near future, were enrolled between January and March 2015 and included in the final analysis. Subjects participated in a 2-week metabolic trial in which they consumed 50 mg of the stable isotope 58Fe, and were then followed for ~ 2 years. The abundance of 58Fe and the total iron concentration in the circulation were measured using Multi-collector Inductively-Coupled Plasma Mass Spectrometry and Atomic Absorption Spectroscopy, respectively. The physiologic requirement for iron during pregnancy was then calculated by the formula derived from our previously published work.ResultsThe mean physiologic requirement for iron in the 11 subjects, across their entire pregnancies, was 3.05 mg.d- 1 in total and 44.0 μg.kg- 1.d- 1 after adjustment for body mass. The physiologic requirements for iron in the first, second, and third trimesters were 2.04 mg.d- 1, 3.26 mg.d- 1, and 4.13 mg.d- 1, respectively. When adjusted for body mass, the physiologic requirements for iron in different trimesters were 32.3 μg.kg- 1.d- 1, 46.9 μg.kg- 1.d- 1, and 55.7 μg.kg- 1.d- 1, respectively.ConclusionWe preliminarily explored the physiologic requirement for iron in pregnant women. The data demonstrated that pregnant women needed about twice iron than non-pregnant women. This research may be helpful for the design of future studies and the modification of iron DRIs.Trial registrationChiCTR, ChiCTR-OCH-14004302. Registered 14 February 2014, http://www.chictr.org.cn/showproj.aspx?proj=5267.

Dataset Information

24-Hour protein, arginine and citrulline metabolism in fed critically ill children - A stable isotope tracer study.

Publications

24-Hour protein, arginine and citrulline metabolism in fed critically ill children - A stable isotope tracer study.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets