Abstract
Background Blood gas (BG) analysis is routine today for patient management in intensive care units. Accurate analysis of different parameters in the BG is essential for managing critical patients. Errors in BG analysis can happen at many levels, with one of them being at sampling and heparinization. We compared self-prepared heparinized syringes rinsed with liquid heparin (LH) and the standard commercially available syringes with dry bound heparin (DBH) for arterial BG analysis of postoperative cardiac surgical patients.
Methods This prospective observational study was conducted in 100 consecutive adult cardiac surgical patients in the cardiac surgical intensive care unit. Paired samples were collected, analyzed immediately, and statistically compared for pH, partial pressure of arterial oxygen (pO2), partial pressure of arterial carbon dioxide (pCO2), oxyhemoglobin saturation (SaO2), HCO, Na+, K+, Cl–, Ca2+, Mg2+, base excess (BE), hemoglobin (Hb), hematocrit, glucose, and lactate. Paired parameters were compared and agreement was evaluated using Bland–Altman difference plots. The 95% limits of absolute agreement (LOA) were compared with total allowable error (TEa).
Results The BG parameters analyzed by two types of heparinized (LH and DBH) syringes were found to be comparable with a negligible mean difference and had an agreement outside the TEa of 8% for pO2, pCO2, and hematocrit, 7% for BE, 6% for Mg2+, 5% for K+, Ca2+, and lactate, 4% for HCOand Na+, 3% for pH, Cl–, Hb, and glucose, and zero for SaO2. The two types of syringes did not show clinically relevant discrepancies among many different parameters as per LOA and TEa limits.
Conclusion In this study, we found that the BG parameters—respiratory, metabolic, and electrolytes—were comparable between the two types of syringes used for sampling. Unlike some previous studies, we did not find statistically significant differences among these analytes, which might have been due to appropriate self-preparation of heparin syringes.