Investigating Differences in Bicarbonate Levels: Exploring Discrepancies between Venous and Arterial Measurements and Evaluating Stability through Time-point Assessments
Shobha C Ramachandra, Akila Prashant, MN Suma, NK Swetha
Citation Information :
Ramachandra SC, Prashant A, Suma M, Swetha N. Investigating Differences in Bicarbonate Levels: Exploring Discrepancies between Venous and Arterial Measurements and Evaluating Stability through Time-point Assessments. Indian J Med Biochem 2023; 27 (3):50-52.
Introduction: Evaluation of acid-base status is crucial in critical care settings, with bicarbonate serving as a key indicator of electrolyte distribution and anion deficit. This study explored the challenges and uncertainties surrounding the quantification and stability of bicarbonate levels, crucial for accurate clinical assessments.
Methods: The study conducted in the clinical biochemistry laboratory of a tertiary care hospital involves a comparative analysis between serum and arterial bicarbonate levels. We examined serum bicarbonate in 31 patient samples, with concurrently calculated arterial values obtained from blood gas analysis reports of the same patients. Additionally, the stability of serum bicarbonate was assessed at different time intervals.
Results: A significant correlation was observed between serum and arterial bicarbonate (r = 0.91), which was reinforced by Bland–Altman analysis. However, the stability assessment revealed a decrease in serum bicarbonate levels at 2 and 4 hours.
Conclusion: This study contributes to the exploration of simplified methods for assessing acid-base status, particularly valuable in less-equipped conditions. The findings underscore the necessity for awareness among healthcare professionals regarding the impact of preanalytical variables, particularly uncapped tube storage, on serum bicarbonate levels.
Kim A, Yamaguchi L, Keswani S, et al. Correlation between serum and arterial blood gas bicarbonate in patients admitted to the intensive care unit. Cureus 2023;15(4):e37703. DOI: 10.7759/CUREUS.37703.
Goundan PN, Willard DL, Sahin–Efe A, et al. Comparison of bicarbonate values from venous blood gas and chemistry panels measured at the time of diagnosis and resolution of diabetes ketoacidosis. J Clin Transl Endocrinol 2019;18:100205. DOI: 10.1016/J.JCTE.2019.100205.
Ball CM, Featherstone PJ. The introduction of blood gases into clinical practice. Anaesth Intensive Care 2024;52(1):3–5. DOI: 10.1177/0310057X231212299.
Chittamma A, Vanavanan S. Comparative study of calculated and measured total carbon dioxide. Clin Chem Lab Med 2008;46(1):15–17. DOI: 10.1515/CCLM.2008.005.
Olver P, Bohn MK, Adeli K. Central role of laboratory medicine in public health and patient care. Clin Chem Lab Med 2023;61(4):666–673. DOI: 10.1515/CCLM-2022-1075.
Kachhawa K, Kachhawa P, Varma M, et al. Study of the stability of various biochemical analytes in samples stored at different predefined storage conditions at an accredited laboratory of India. J Lab Physicians 2017;9(1):11–15. DOI: 10.4103/0974-2727.187928.
Chauhan KP, Patel JD, Prajapati S. Study of specimen stability for biochemical parameters. Int J Clin Biochem Res 2020;5(1):158–163. DOI: 10.18231/2394-6377.2018.0032.
de Andrade LGM, Muniz AB, Mondelli AL, et al. Concordance analysis between dosed serum bicarbonate and that calculated by gas analysis in chronic renal patients. J Bras Nefrol 2020;42(4):478. DOI: 10.1590/2175-8239-JBN-2019-0236.
Nargis W, Rahman AS, Ahamed BU, et al. Comparison of values of traditionally measured venous bicarbonate with calculated arterial bicarbonate in intensive care unit patients of a hospital in a third-world country. Niger Med J 2014;55(4):285. DOI: 10.4103/0300-1652.137186.
Sanghavi SF, Albert TJ, Swenson ER. Will the real bicarbonate please stand up? Ann Am Thorac Soc 2022;19(7):1226–1229. DOI: 10.1513/AnnalsATS.202111-1286CC.
Šupak–Smolčić V, Franin L, Horvat M, et al. Serum bicarbonate stability study at room temperature: Influence of time to centrifugation and air exposure on bicarbonate measurement reported according to the CRESS checklist. Clin Chem Lab Med 2023;61(6):1046–1053. DOI: 10.1515/cclm-2022-1182.
