Sodium Examination Procedure (Semi Autoanalyzer)

1.Purpose of Examination: To lay down standard operating procedure for serum Sodium by ISE Method in Biochemistry section of LSSTH, Bhavnagar.

2.Principle: Ion Selective Electrode.

3.Performance: Linearity – 110-186 mEq/L Precision – It is determined from 2 runs per day with two replicates per run for 20 days on two AFT 300 Electrolyte Analyzer.

4.Primary Sample: Plasma or serum sample_collection_manual

5.Patient Preparation: Verbal consent of patient should be taken before collecting blood sample.

6.Type of Container: Plain Vaccute with no additive

7.Required Equipment: Centrifuge, Electrolyte auto analyzer

8.Safety Precaution: Follow the universal work precautions.

9.Calibration Procedure: Instrument performs auto calibration every four hours. Manual calibration is done on following circumstances:

1. After instrument repair
2. After new reagent lot
3. QC data not satisfactory - QC outlier
4. after each replacement of the Fluidpack

10.Procedural Steps: Centrifuge the blood sample, open the sample door of the instrument ,than hold the Vacutte under the probe to be aspirated

11.Quality Control Procedure: The Laboratory runs Internal Quality control level 1, level 2 & level 3 once a day. Monthly L-J charts are reviewed & for any QC outlier root cause analysis are done & corrective actions are taken according to error. Participated in RIQAS programme. RIQAS reports is reviewed and if any result go outlier, than root cause analysis is done & corrective actions are taken according to error.

12.Interferences & Cross-Reactions: Lipemia, Hemolysis.

13.Principle of Procedure for Calculating Results: Membrane potential is caused by the permeability of certain types of membranes to selected anions or cations. The potential produced at the membrane –solution interface is proportional to the logarithm of the ionic activity or concentration of sodium Ion

14.Biological Reference Interval: 135-145 mEq/L

15.Reportable interval of patient examination results: 120 -160 mEq/L

• Instruction for determining Quantitative results when a results is not within the measurement

Rerun the sample and correlate clinically

16.Critical Value: <120 mEq/L and >160 mEq/L

17.Laboratory Interpretation: The common causes of High Sodium Level are as follows: It is associated with conditions with water loss in excess of salt loss in conditions with Profuse sweating, severe vomiting or Diarhoea, Diabetes Insipidus, Hyperaldosteronism, Cushing’s Syndrome. The common causes of Low Sodium Level are as follows: Excessive I.V. Fluids, Diuretics, Salt Losing Nephropathy, Metabolic acidosis, cardiac failure, Hepatic failure, Hypothyroidism

18.Stability of sample Serum or plasma-At Room temperature18°–28°C (64°–82°F) stability ≤ 24 hours CSF- At Refrigerated 2°–8°C (36°–46°F) stability 3 days

19.Storage of sample 2-8° C for 1 days (Retention period for re-examination and/or additional tests is 24 hrs. at (2-8° C).

20.Reagent Storage and stability Unopened reagents is stable until expiration date when store at 2-8°c.Reagent stability is 30 days if reagent is uncapped and onboard.

21.Turn around time (TAT) 6.0 hours after collection, in case of emergency 2.0 hours.

22.Potential source of variation:

1. Expiry of Kit
2. Instrumental Error
3. Presence of interfering source
4. Instrumental Error
5. Reagent contamination
6. Storage condition not proper

23.Reagent Handling Remove any air bubbles present in the reagents with a new applicator stick, or allow the reagents to sit at the appropriate storage temperature to allow the bubbles to dissipate. To minimize volume depletion, do not use a transfer pipette to remove bubbles

24.REFERENCE:

1. Friedman R. Young D.S.:Effects of Disease on Clinical Laboratory Tests, AACC Press, Washington, D.C. 1989
2. Komberg A., Horecker B.L.: Methods in Enzymology, Colowickand Kaplan, edes. Vol. 1, Academic Press, New York 323, 1955.
3. Batheimal W., Czock R., Enzymatic determination of glucose in the blood, cerebrospinal fluid and urine, Klin.Wochenncschr., 40:585, 1962.
4. Tietz Textbook of Clinical Chemistry, W.B. saunders, Philadelphia, PA, 3 rd edition 1999, pp. 776-82.
5. Westgard J. Barry P., cost Effective Quality Control: Managing the Quality and productivity of Analitycal Processes, AACC press, Washington, D.C. 1986
6. Tietz Textbook of Clinical Chemistry, W.B. saunders, Philadelphia, PA, 3 rd edition 1999, pp. 1815.
7. Young D.S., Effects of Drugs on Clinical Laboratory Tests, AACc Press Washington, D.C., 1990.
8. Document EP3-T:”Guidelines for Manufacturers for Estabilishing Performance Claims for Clinical Chemical Methods, Replication Experiment Evaluation”, National Committee for Clinical Laboratory Standards, Villanova, Pa, 1982.
9. 9.Roche Ise Indirect Na K Cl 0005883962001c501V13.0
10. 10. NABL 112 effective from 01/06/2019