RT Journal Article
SR Electronic
T1 Effects of Syringe Material, Sample Storage Time, and Temperature on Blood Gases and Oxygen Saturation in Arterialized Human Blood Samples
JF Respiratory Care
FD American Association for Respiratory Care
SP 732
OP 736
VO 51
IS 7
A1 Thomas P Knowles
A1 Rory A Mullin
A1 Jefferson A Hunter
A1 Herbert F Douce
YR 2006
UL http://rc.rcjournal.com/content/51/7/732.abstract
AB BACKGROUND: The practice of on-ice storage of arterial-blood samples in plastic syringes for delayed analysis continues, and the effects of storage time and temperature on the measurement of blood-oxygen-saturation values (SaO2) have not been adequately described. OBJECTIVE: To determine the effects of syringe material, storage time, and storage temperature on normal arterialized blood gas and SaO2 values. METHODS: We used a temperature-controlled extracorporeal circuit to “arterialize” 500 mL of fresh, whole human blood at 37°C, and we used certified calibration gases of 12% O2 and 5% CO2 to produce normal blood-gas values. From that arterialized blood we took 90 samples and randomly assigned them to 6 groups, until there were 15 samples in each group. The groups were (1) plastic syringe, analyzed immediately, (2) plastic syringe, stored 30 min at 0-4°C, (3) plastic syringe, stored 30 min at 22°C, (4) glass syringe, analyzed immediately, (5) glass syringe, stored 30 min at 0-4°C, and (6) glass syringe, stored 30 min at 22°C. RESULTS: Compared to the samples that were analyzed immediately, the PO2 of the samples stored in plastic syringes for 30 min at 22°C and at 0–4°C was significantly higher, with a clinically important magnitude of 11.9-13.7 mm Hg. The PCO2 of blood stored in glass for 30 min at 0-4°C was significantly lower, although the magnitude of the difference (1.5 mm Hg) was not clinically important. There were no statistically significant differences in pH or oxygen saturation among the 6 groups. CONCLUSION: For accurate arterial-blood-gas results, samples drawn in plastic syringes should be analyzed immediately. If the analysis is going to be delayed, the samples should be drawn and stored in glass.