Stability of heparinized plasma contacting with cells for clinical chemistry assays

Abstract

Heparinized plasma specimens are widely used in clinical chemistry laboratory to reduce turn around time (TAT). This study was aimed to investigate the stability of the heparinized plasma contacting with cells during 7 h. period at room temperature.  One hundred heparinized plasma samples of out-patient department at Chao Phya Abhaibhubejh Hospital, Prachinburi were used as the primary tubes.  Blood chemistry were analysed by Olympus AU400 automatic analyzer within 1 h after collection and continued every hour for 7 h. The level of glucose, blood urea nitrogen, creatinine, sodium, potassium, chloride, and total carbon dioxide at 7 h. compared to 1 h. were changed to +10 %, +2.0 % +0.7 % +1.0 mmol/L, 0.0 mmol/L, 0.0 %, and -14.5 %, respectively.  However, the differences of all tests were still in an acceptable range of total allowable error limit except for glucose.  Significant differences were observed for concentration of glucose at  2 h., blood urea nitrogen at 4 h., and electrolyte at 2 h. (P < 0.05),  but not for creatinine. The   results show heparinized plasma exposed cells is stable for urea nitrogen, creatinine, sodium, potassium, chloride and total carbon dioxide assays 7 h. after blood collection. However, for accurate glucose value, the plasma should be analyzed as soon as possible.