title: Pre-analytical factors affecting the results of laboratory blood analyses in farm animal veterinary diagnostics.
abstract: The quality of the laboratory diagnostic approach in farm animals can be severely affected by pre-analytical factors of variation. They induce increase/decrease of biochemical and hematological analyte concentrations and, as a consequence, they may cause unsuitable conclusions and decisions for animal health management and research projects. The pre-analytical period covers the preparation of sampling, the sampling procedure itself, as well as all specimen handling until the beginning of the specific laboratory analysis. Pre-analytical factors may have either an animal-related or a technique-related background. Animal-related factors cover daytime/season, meals/fasting, age, gender, altitude, drugs/anesthesia, physical exercise/stress or coinfection. Technique-related factors are the choice of the tube including serum v. plasma, effects of anticoagulants/gel separators, the anticoagulant/blood ratio, the blood collection procedure itself, specimen handling, contamination, labeling, storage and serum/plasma separation, transportation of the specimen, as well as sample preparation before analysis in the laboratory. It is essential to have proper knowledge about the importance and source of pre-analytical factors to alter the entire diagnostic process. Utmost efforts should be made to minimize controllable factors. Analytical results have to be evaluated with care considering that pre-analytical factors of variation are possible causes of misinterpretation.
authors.affiliation: Division Laboratory Medicine, Clinic for Swine and Small Ruminants, Forensic Medicine and Ambulatory Service, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, D-30173 Hannover, Germany. esther.humann@tiho-hannover.de
authors.forename: E
authors.initials: E
authors.lastname: Humann-Ziehank
authors.forename: M
authors.initials: M
authors.lastname: Ganter
mesh_terms: D000367:Age Factors; D000531:Altitude; D000818:Animals; D000829:Animals, Domestic; D001774:Blood Chemical Analysis / Q000379:methods* / Q000662:veterinary*; D003951:Diagnostic Errors / Q000662:veterinary*; D019937:Diagnostic Techniques and Procedures / Q000662:veterinary*; D012621:Seasons; D012737:Sex Factors; D013048:Specimen Handling / Q000009:adverse effects; D013312:Stress, Physiological / Q000502:physiology; D013997:Time Factors; D014730:Veterinary Medicine / Q000379:methods*