THE IMPACT OF DIFFERENT VOLUMES OF HEPARIN ON PH, PCO2 AND HCO3 - READINGS DURING BLOOD GAS SAMPLING

Background : Mistakes in blood gas sampling influence the cre dibility of blood gas readings. Volume of heparin used as anticoagulant may change readings through its dilutional direct binding and compositional actions Objective : To evaluate the influence o f various volumes of heparin during blood gas sampling on PH, PCO2 and HCO3 - readings. Methods : Our double blind, randomized and prospective investigation included 105 adult patients, of both sexes, aged 34 - 46 years and admitted at our intensive care unit , King Hussein hospital, King Hussein medical center, Amman, Jordan, during the period Feb.2013 - Aug.2015, after obtaining written informed consent from all guardians and approval from the Royal ethical and research committee. Patients were divided randomly into three groups. Group I patients (n=35) received heparinized syringe for blood gas sampling using 25 IU of heparin. Group II patients (n=35) received heparinized syringe for blood gas sampling using 50 IU of heparin. Group III patients (n=35) received heparinized syringe for blood gas sampling using 100 IU of heparin. A total volume of 1 ml blood in each syringe was received and analyzed by blood gas analyzer. Statistical analysis was performed using Friedman’s test and Wilcoxon test. Results : There wa s a significant discrepancy regarding the readings of pH, PCO2 and HCO3 - in the three syringes (P < 0.05). The PCO2 and HCO3 - readings reduced with the increasing volume of heparin. Conclusion : Least heparin used during blood gas sampling is most suitabl e for assessing PH, PCO2 and HCO3 - . The technique of blood gas sampling should have a standard protocol regarding volume of heparin used.