Effects of blood storage on ice in biochemical and arterial blood gas analysis of rats.

PURPOSE To investigate the effects of blood storage in biochemical and arterial blood gas analysis of Wistar rats. METHODS Ten adult male rats with weights between 300-350 g were used. The catheterization of the internal carotid artery were performed, followed by withdrawal of 3 ml of blood using 3 separate syringes each containing 1 ml. The syringes were fulfilled one after another and numerated according to the order of collection. Then, the following groups were devised: GT1 - samples that were firstly analyzed in 20 minutes and the second exam 65 minutes after the collection; GT2 - samples that were firstly analyzed in 35 minutes and the second exam 80 minutes after the collection; GT3 - samples that were firstly analyzed in 50 minutes and the second exam 95 minutes after the collection. The samples were stored in a container with a temperature between 0 C masculine and 4 C masculine. Upon analysis the values of pH, PaCO2, PaO2, HCO3-, SatO2, SBE, Na+ and K+ concentrations and glucose were compared. RESULTS No statistically relevant difference (p<0.05) between the GT1, GT2 or GT3, when measuring pH, PaCO2, PaO2, HCO3-, SatO2, SBE or glucose, were found. However, Na+ concentration decreased and the K+ concentration increased (p<0.05) when comparing the first analysis (20 minutes) with the last one (95 minutes). CONCLUSION The blood storage on ice does not interfere in the results of arterial blood gas analysis for the period of at least 95 minutes, except for the Na+ e K+ levels, which are practicable until 80 minutes after storage.