Delay in Specimen Processing-Major Source of Preanalytical Variation in Serum Electrolytes
Published: December 1, 2014 | DOI: https://doi.org/10.7860/JCDR/2014/.5285
Ankur Baruah, Parul Goyal, Saket Sinha, K L Ramesh, Rashmirasi Datta
1. Senior Resident, Department of Biochemistry, Pgimer and Dr Rml Hospital, New Delhi, India.
2. Assistant Professor, Department of Biochemistry, Pgimer and Dr Rml Hospital, New Delhi, India.
3. Senior Resident, Department of Biochemistry, Pgimer and Dr Rml Hospital, New Delhi, India.
4. Head of Department, Department of Biochemistry, Pgimer and Dr Rml Hospital, New Delhi, India.
5. Senior Resident, Department of Biochemistry, Lady Hardinge Medical College, New Delhi, India.
Correspondence
Dr. Ankur Baruah,
Pgimer and Dr Rml Hospital, Department of Biochemistry, Baba Kharag Singh Marg, New Delhi-110001, India.
Phone : (011) 25074822, Mobile : 9711252766, E-mail : drabaruah15@gmail.com
Objective: To evaluate the stability of electrolytes in serum samples due to delay in analysis in a tertiary care government hospital in India, and the maximum time delay acceptable between sample centrifugation and analysis.
Materials and Methods: We estimated serum electrolytes of 400 samples with different time intervals between centrifugation and sample analysis on automated analyser.
Results: Values were compared using repeated measure ANNOVA and acceptable limit change using in house QC values of 6 months. During the time interval between centrifugation and sample analysis, the samples were kept uncovered in sample cups in the laboratory. Potassium values show significant changes within 1 h (T1, p<0.01) but sodium (T2, p <0.01) and chloride (T2, p <0.001) values are acceptable up to a time delay of 3 h between sample centrifugation and analysis.
Conclusion: Samples for electrolytes should be analysed within 1-2 h of centrifugation and if there is any delay in analysis, the samples should be stored under proper conditions.
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