Mar 04, 2026
COMPARISON OF SODIUM LEVELS BY BLOOD GAS ANALYSER AND LABORATORY AUTOANALYSER
- Vivek Hari1,2,3,
- Ayushi Gupta1,2,4,
- Chakrapani M1,2,4
- 1Department of General Medicine;
- 2Kasturba Medical College, Mangalore;
- 3Manipal Academy of Higher Education, Manipal, Karnataka, India- 576104Kasturba Medical College, Mangalore;
- 4Manipal Academy of Higher Education, Manipal, Karnataka, India- 576104
Protocol Citation: Vivek Hari, Ayushi Gupta, Chakrapani M 2026. COMPARISON OF SODIUM LEVELS BY BLOOD GAS ANALYSER AND LABORATORY AUTOANALYSER. protocols.io https://dx.doi.org/10.17504/protocols.io.q26g77o11gwz/v1
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
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Created: March 04, 2026
Last Modified: March 04, 2026
Protocol Integer ID: 247855
Keywords: laboratory autoanalyser abstract hyponatremia, comparison of sodium level, accurate monitoring of sodium, blood gas analyser, blood gas analyzer, sodium value, serum sodium, sodium level, sodium estimation, adult patients with symptomatic hyponatremia, symptomatic hyponatremia, venous blood sample, derived sodium value, sodium, laboratory autoanalyzer, abg analyzer, common electrolyte disorder, intensive care setting, intensive care units of kasturba medical college, comparable to laboratory measurement, laboratory measurement, osmotic demyelination syndrome, intensive care unit
Abstract
Abstract
Hyponatremia (serum sodium <135 mmol/L) is the most common electrolyte disorder and may result in significant morbidity and mortality, particularly in acute or severe cases. Rapid and accurate monitoring of sodium is crucial during correction to prevent complications such as cerebral edema or osmotic demyelination syndrome. While laboratory autoanalyzers are routinely used for sodium estimation, blood gas analyzers (ABG) provide faster results and are widely used in emergency and intensive care settings. However, concerns exist regarding the agreement between these two methods.
This observational cross-sectional study will be conducted among 30 adult patients with symptomatic hyponatremia presenting to the emergency room or intensive care units of Kasturba Medical College. Venous blood samples will be analyzed simultaneously using an ABG analyzer and a laboratory autoanalyzer. Agreement between the two methods will be assessed statistically.
The study aims to determine whether ABG-derived sodium values are clinically comparable to laboratory measurements for time-sensitive management decisions.
Materials
ABG analyser, Laboratory ion exchange
Troubleshooting
METHOD OF STUDY
Patients presenting to ER and inpatients in ICUs of teaching hospitals of Kasturba Medical College, Mangalore.
The study is designed as an observational, cross-sectional analysis, institutional based study.
The study will involve participation of patients presenting to ER with symptomatic hyponatremia and inpatients with hyponatremia.
All patients presenting with symptomatic hyponatremia, acute or chronic in nature or are admitted with symptomatic hyponatremia.
Exclusion criteria includes, age younger than 18 years, patients with severe hyperglycaemia (RBS 3e300mg/dl) and patients with Myeloma (paraproteinemia).
To be calculated based on expected.
We will take 30 patients presenting to ER and inpatients for the study.
Data will be coded and recorded in MS Excel spreadsheet program. Statistical significance will be kept at p 3c 0.05.
The sampling method used is a purposive convenience sampling technique.
ABG analyser, Laboratory ion exchange.
Identification of patients with symptomatic hyponatremia in ER and inpatients of KMC Teaching Hospitals.
Taking Informed Consent from the Patient or bystander to participate in the study in their own understandable language.
Venous blood collection and estimation of sodium with iSTAT machine.
Venous blood collection in Clot activator tube.
Serum sodium analysis by Lab autoanalyzer.
Data analysis.
Inference.
The present study is planned to investigate whether electrolyte levels assessed using ABG analyser and electrolyte analyser are equivalent.
If equivalent, it will help to use arterial blood gas analyser as a tool to quickly assess the sodium levels aiding in swift treatment decisions and to monitor treatment response.
Protocol references
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)
1. Sterns RH. Treatment of Severe Hyponatremia. Clin J Am Soc Nephrol. 2018 Apr 6;13(4):641-649. doi: 10.2215/CJN.10440917. Epub 2018 Jan 2. PMID: 29295830; PMCID: PMC5968908.
2. Valle, Jana M.; Beveridge, Alexander; Chríoinín, Danielle Ní (2022-02-16). "Exploring hyponatremia in older hospital in-patients: management, association with falls, and other adverse outcomes". Aging and Health Research. 2: 100060. doi:10.1016/j.ahr.2022.100060
3. Waikar SS, Mount DB, Curhan GC. Mortality after hospitalization with mild, moderate, and severe hyponatremia. Am J Med. 2009 Sep;122(9):857-65. doi: 10.1016/j.amjmed.2009.01.027. PMID: 19699382; PMCID: PMC3033702.
4. Hawkins RC. Age and gender as risk factors for hyponatremia and hypernatremia. Clin Chim Acta. 2003 Nov;337(1-2):169-72. doi: 10.1016/j.cccn.2003.08.001. PMID: 14568195.
5. Arieff AI. Hyponatremia, convulsions, respiratory arrest, and permanent brain damage after elective surgery in healthy women. N Engl J Med. 1986 Jun 12;314(24):1529-35. doi: 10.1056/NEJM198606123142401. PMID: 3713746.
6. Garrahy A, Cuesta M, Murphy B, O'Reilly MW, Tormey WP, Sherlock M, Thompson CJ. Active management of severe hyponatraemia is associated with improved mortality. Eur J Endocrinol. 2021 Jan;184(1):9-17. doi: 10.1530/EJE-20-0577. PMID: 33112271.
7. Lambeck J, Hieber M, Dreßing A, Niesen WD. Central Pontine Myelinosis and Osmotic Demyelination Syndrome. Dtsch Arztebl Int. 2019 Sep 2;116(35-36):600-606. doi: 10.3238/arztebl.2019.0600. PMID: 31587708; PMCID: PMC6804268.
8. Shafiee MA, Charest AF, Cheema-Dhadli S, Glick DN, Napolova O, Roozbeh J, Semenova E, Sharman A, Halperin ML. Defining conditions that lead to the retention of water: the importance of the arterial sodium concentration. Kidney Int. 2005 Feb;67(2):613-21. doi: 10.1111/j.1523-1755.2005.67117.x. PMID: 15673308.
9. Triplett KE, Wibrow BA, Norman R, Hince DA, Hardy LE, Tan S, Ho KM, Anstey MH. Can the blood gas analyser results be believed? A prospective multicentre study comparing haemoglobin, sodium and potassium measurements by blood gas analysers and laboratory auto-analysers. Anaesth Intensive Care. 2019 Mar;47(2):120-127. doi: 10.1177/0310057X19840046. Epub 2019 May 9. PMID: 31070468.
10. Rivers PA, Dobalian A, Germinario FA. A review and analysis of the clinical laboratory improvement amendment of 1988: compliance plans and enforcement policy. Health Care Manage Rev. 2005 Apr-Jun;30(2):93-102. doi: 10.1097/00004010-200504000-00003. PMID: 15923911.
11. Lima-Oliveira G, Lippi G, Salvagno GL, Montagnana M, Picheth G, Guidi GC. Different manufacturers of syringes: a new source of variability in blood gas, acid-base balance and related laboratory test? Clin Biochem. 2012 Jun;45(9):683-7. doi: 10.1016/j.clinbiochem.2012.03.007. Epub 2012 Mar 13. PMID: 22440459.
12. Gibbons M, Klim S, Mantzaris A, Dillon O, Kelly AM. How closely do blood gas electrolytes and haemoglobin agree with serum values in adult emergency department patients: An observational study. Emerg Med Australas. 2019 Apr;31(2):241-246. doi: 10.1111/1742-6723.13133. Epub 2018 Jul 19. PMID: 30027670.
13. Leino A, Kurvinen K. Interchangeability of blood gas, electrolyte and metabolite results measured with point-of-care, blood gas and core laboratory analyzers. Clin Chem Lab Med. 2011 Jul;49(7):1187-91. doi: 10.1515/CCLM.2011.185. Epub 2011 Apr 20. PMID: 21504373.
Acknowledgements
Source of Funding for the Research: MAHE, MANIPAL
Declare Self-funding:
I declare that the study subjects will not be made to pay for the special investigations/devices/medications. The cost will be borne by me or procured from research grants of MAHE, MANIPAL.
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