Stabilnost kalija, natrija, klorida, laktat dehidrogenaze i indeksa hemolize u uzorku seruma neodvojenog od stanica

master's thesis

• Title (english): The stability of potassium, sodium, chloride, lactate dehydrogenase and the index of hemolysis in serum samples after prolongated contact with blood cells
• Author: Tina Brenčić
• Mentor: Ana-Maria Šimundić (mentor)
• Committee member: Ana-Maria Šimundić
• Committee member: Anita Somborac Bačura
• Committee member: Sandra Šupraha Goreta
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of medical biochemistry and haematology); Zagreb
• Defense date and country: 2015-07-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Medical Biochemistry

Abstract

Važan problem s kojim se medicinsko-biokemijski laboratoriji suočavaju u svakodnevnom radu je koliko je pojedina mjerena veličina stabilna u uzorku seruma neodvojenog od stanica. Prema preporukama HKMB, dozvoljeno vrijeme od uzimanja uzorka do analize za opće biokemijske pretrage je 6 sati. Cilj ovog istraživanja je utvrditi stabilnost mjerenih veličina: kalija, natrija, klorida, laktat dehidrogenaze i indeksa hemolize u takvom uzorku tijekom 8 sati. Ispitana je i ovisnost odstupanja mjerenih veličina od početnog mjerenja između pojedinih podskupina podijeljenih s obzirom na broj stanica; eritrocita, leukocita i trombocita te postoji li razlika u koncentraciji kalija, natrija, klorida te aktivnosti laktat dehidrogenaze u različitim dijelovima uzorka.Istraživanje je provedeno u KBC ''Sestre Milosrdnice'', u Kliničkom zavodu za kemiju. Prikupljeno je 50 venskih uzoraka seruma u svrhu praćenja stabilnosti mjerenih veličina tijekom 8 sati. Analiza se vršila 2, 4, 6 i 8 sati od prvotnog određivanja. Prosječno odstupanje svake mjerene veličine u određenim vremenskim točkama uspoređeno je s poželjnim specifikacijama za nepreciznost i ukupnu pogrešku temeljenim na biološkoj varijabilnosti te rezultatima vanjske procjene kvalitete organizatora CROQALM. Kruskal-Wallisovim testom utvrđena je ovisnost odstupanja mjerenih veličina od početnog mjerenja između pojedinih kvartilnih podskupina broja stanica. Dodatnih 10 uzoraka korišteno je za utvrđivanje razlike u koncentraciji mjerenih veličina u različitim dijelovima uzorka; na vrhu, u sredini i na dnu epruvete. Analiza se vršila na biokemijskom analizatoru ARCHITECT c8000. Za statističku analizu podataka korišteni su testovi Friedman ANOVA i RM ANOVA. Rezultati istraživanja pokazali su porast koncentracije svih mjerenih veličina tijekom 8 sati. Što se tiče razlike u koncentraciji u različitim dijelovima uzorka, ona postoji za natrij, kloride i laktat dehidrogenazu. Na temelju naših rezultata preporučeno je kalij, natrij, kloride i laktat dehidrogenazu određivati unutar 2 sata od uzorkovanja u uzorku seruma koji stoji na stanicama. Odstupanje mjerenih veličine kroz vremenski period od 8 sati ne raste u ovisnosti o broju stanica. Istraživanjem je potvrđena nereproducibilnost metode za određivanje laktat dehidrogenaze u uzorku seruma gdje također postoji pogreška prilikom njezinog određivanja.

Abstract (english)

An important problem that clinical laboratories deal with in their daily work is how long a certain measured value is stable in serum samples after its prolongated contact with blood cells. According to the recommendations of HKMB, the allowed time from sampling to analysis for general biochemistry is 6 hours. The aim of this study was to evaluate the stability of the measured values of: potassium, sodium, chloride, lactate dehydrogenase and the index of hemolysis in such a sample during 8 hours. The dependence of the mean bias from initial testing for every measured value was invetigated regarding the number of cells; erythrocytes, leukocytes and platelets, and determined if is there was a difference in the concentrations of potassium, sodium and chloride and lactate dehydrogenase activity in different parts of the sample. The study was conducted in KBC ''Sestre Milosrdnice’’, in the Department of Chemistry. 50 venous serum samples were collected in order to monitor the stability of measured values over 8 hours. Analysis was carried out 2, 4, 6 and 8 hours after the initial measurement. The mean bias of each measured value in different time points was compared with the desired specifications for imprecision and total error based on biological variation and the results of the external quality control organizated by CROQALM. Additional 10 samples were used to determine the difference in the concentration of measured values in different parts of the sample; at the top, in the middle and at the bottom of the tube. The analysis was carried out on the biochemistry analyzer ARCHITECT c8000. Friedman ANOVA test and RM ANOVA test were used for statistical data analysis. The results showed an increase of the concentration of all measured values during 8 hours. The difference of concentrations in different parts of the sample exists for sodium, chloride and lactate dehydrogenase. Based on our results, we recommend that potassium, sodium, chloride and lactate dehydrogenase should be measured within 2 hours of sampling serum specimen standing on the cells. The mean bias of the measured value in a time period of 8 hours did not increases in dependence of the number of cells. Our study confirmed irreproducibility of the method for assesment of lactate dehydrogenase in serum.

• Keywords: kalij; natrij; kloridi; laktat dehidrogenaza; indeks hemolize; stabilnost; serum; stanica
• Keywords (english): potassium; sodium; chloride; lactate dehydrogenase; stability; serum; cell
• Language: croatian
• URN:NBN: urn:nbn:hr:163:062243
• Study programme: Title: Medical Biochemistry; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra medicinske biokemije (magistar/magistra medicinske biokemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2016-01-19 10:45:43