A Comparative Study on the Effects of Dry Electrolyte Balanced Heparin Versus Liquid Heparin on Arterial Blood Gas Parameters in Critically Ill Patients

Abstract

Background: Arterial Blood gas (ABG) analysis is an important investigation and diagnostic tool done on patients admitted in Critical Care Units (CCUs). ABG analysis is used to monitor acid base balance and effectiveness of gas exchange. It is also important in evaluating response to therapeutic and diagnostic interventions, electrolyte and metabolite imbalances and even monitoring progress and severity of diseases. This information enables clinicians in effective diagnosis and management of life-threatening pathophysiological processes in critically ill patients, which greatly improves their prognosis and outcomes. Multiple errors are encountered during the ABG analysis process. ABG samples require artificial anticoagulation with heparin to prevent in-vitro clotting. Objective: To evaluate the effects of Dry electrolyte balanced heparin compared to Liquid heparin on arterial blood gas parameters. Design: A comparative cross-sectional study involving 46 patients admitted at the Kenyatta National Hospital (KNH) Main CCU. Methodology: Patients aged 18 years and above admitted to the KNH Main CCU were enrolled consecutively upon admission to the CCU. Two ABG samples were collected from the same patient concurrently, one in a dry electrolyte balanced heparin syringe and the second in a syringe coated with liquid heparin. They were analyzed using the ABL800 FLEX blood gas analyzer and the LH ABG parameters compared to DBH ABG parameters. Data Analysis: Patients’ demographic and clinical characteristics were analyzed and presented as frequencies and proportions. The paired samples t-tests method was used to elucidate the strength of association between the two sets of ABG parameters upon the use of LH and DBH. The statistical significance level was set at α=0.05. Comparative data analysis was conducted using the Bland Altman methodology Results: This study established clinically equivalent results for pH, pO2, pCO2, HCO3, K+ and Hemoglobin between the LH and DBH group. However, the differences in Na+ and Cl- between the two groups were statistically significant. The additives in LH upregulated the two parameters. Conclusion: There was no significant advantage of using DBH over LH for ABG anticoagulation of pH, pO2, pCO2, HCO3 and haemoglobin. When the LH has been flushed out completely, the LH and DBH syringes could be used interchangeably for these parameters. Liquid Sodium Heparin affected Na and CL electrolytes, even in very small amounts. DBH would be the preferred anticoagulant when assessing these two electrolytes