[Problems of commercially available heparinized syringes in measurements of blood gases and electrolytes].

We compared the measured values of blood gases and electrolytes by commercially available heparinized syringes (PZ-II, Quick-lite and QS90) with normal and decreased calcium concentrations. With normal calcium concentration, the measured value of [Ca2+] in PZ-II was significantly less than that in Quick-lite and QS90, seemingly due to contained heparin. With hypocalcemia, the measured values of [Ca2+] in Quick-lite and QS90 were significantly greater than those in non-heparinized syringe. The pH and PO2 decreased, and PCO2 increased as time passed. The [Ca2+] was suggested to be more influenced by heparin than by acid-base balance.