title: Description of an Automated Method for Urea Nitrogen Determination in Bronchoalveolar Lavage Fluid (BALF) of Neonates and Infants.
abstract: Bronchoalveolar lavage (BAL) partially recovers both the instilled saline and the alveolar fluid, so-called epithelial lining fluid (ELF), but a correction for the dilution due to the BAL technique itself is needed to know the amount of recovered ELF. In this regard, urea nitrogen may be useful and has been proposed to calculate ELF. The aim of the present study was to develop and validate a new method to measure urea nitrogen in BAL fluid (BALF). We used 19 BALF samples obtained from neonates and infants with different respiratory conditions. The urea nitrogen assay was carried out on Cobas c311 analyzer (Roche Diagnostics). A validation study shows that the method is perfectly linear (R(2) = 0.999), sensitive (limit of detection = 0.055 mg/dL; limit of quantification = 0.16 mg/dL), repeatable (low = 0.15 ± 0.02, 13.3%; high = 1.80 ± 0.02, 1.1%), reproducible (low = 0.14 ± 0.02, 14.2 %; high = 1.76 ± 0.04, 2.2 %) with accuracy ranging between 93-96%. Our results support the robustness of validated procedure since the described method appears simple, precise, rapid, and suitable for routine analysis. Thus, it may be used to correct concentration of various noncellular BAL components and calculate their ELF amounts in neonates and infants.
authors.affiliation: Institute of Biochemistry and Clinical Biochemistry, Catholic University of the Sacred Heart, Rome, Italy krizia.pocino@gmail.com.
authors.forename: Krizia
authors.initials: K
authors.lastname: Pocino
authors.affiliation: Institute of Biochemistry and Clinical Biochemistry, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Minucci
authors.affiliation: Institute of Biochemistry and Clinical Biochemistry, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Rocco
authors.initials: R
authors.lastname: Manieri
authors.affiliation: Pediatric Intensive Care Unit, Department of Critical Care University Hospital "A. Gemelli," Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Conti
authors.affiliation: Pediatric Intensive Care Unit, Department of Critical Care University Hospital "A. Gemelli," Catholic University of the Sacred Heart, Rome, Italy Division of Pediatrics and Neonatal Critical Care, South Paris University Hospitals Medical Center, "A. Beclere," APHP, Paris, France.
authors.forename: Daniele
authors.initials: D
authors.lastname: De Luca
authors.affiliation: Institute of Biochemistry and Clinical Biochemistry, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Ettore Domenico
authors.initials: ED
authors.lastname: Capoluongo
mesh_terms: D057205:Automation, Laboratory / Q000379:methods*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009584:Nitrogen / Q000032:analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014508:Urea / Q000032:analysis*
chemical_list: D014508:Urea; D009584:Nitrogen
keywords: bronchoalveolar lavage fluid; method validation; neonates and infants; urea nitrogen assay