Acid-base balance Archives - Revista Brasileira de Ginecologia e Obstetrícia

PURPOSE: to evaluate the effect of lyophilized and liquid heparin on umbilical cord blood pH measure. METHOD: we carried out a prospective study with 102 newborn arterial umbilical cord blood samples at the Obstetrics Department of the "Hospital Geral de Caxias do Sul". The authors used 51 syringes previously prepared with lyophilized heparin (syringe A) and 51 syringes prepared with liquid heparin (syringe B) for sample collection. Immediately after delivery a segment of the umbilical cord was doubly clamped and blood samples were obtained for measurements of pH and gases. The umbilical arterial blood pH was analyzed within 20 minutes by an AVL OMNI pH analyzer (Vienna, Austria). RESULTS: the average values of umbilical cord arterial blood pH in groups A and B were 7.246±0.086 and 7.244±0.084, respectively. The analysis showed no significant differences between blood samples in both syringes. CONCLUSION: we conclude that the two types of syringes have similar effects on blood pH analysis, allowing us to choose the less expensive one.