J Korean Soc Emerg Med.  2000 Mar;11(1):27-34.

The Study of Changes in Arterial Blood Gas Finding with Time Interval

• Cho NS
• Kim CH

Abstract

BACKGROUND: Arterial blood gas analysis are highly susceptible to preanalytic error due to improper method of obtaining or handling the blood sample before analysis. The error in measurement of blood gas analysis are loss of CO2 by exposure to atmospheric air, effect of anticoagulant itself, temperature difference between the experimental subject and the measuring electrode and metabolic change which occur between blood sampling and measurement. METHOD: To study the effect of the delay in estimation of blood gas and drawn blood on values of blood gas partial pressure and pH. Blood sample were divided into 2 groups according to the method of storage, group I stored at 24~25degrees C(room temperature) under anaerobic condition. ;group II stored at 0~4degrees C(refrigerator) under anaerobic condition. The samples were analyzed by time interval through 180 minutes in each group.
RESULTS
The result were as follows: 1) PaO2 decreased significantly after 10 mins in group I, whereas it decreased significantly after 20 mins in group II. 2) PaO2 increased significantly after 20 mins in group I, whereas it increased significantly after 120 mins in group II. 3) pH decreased significantly after 60 mins in group I, whereas it decreased significantly after 120 mins in group II. 4) No significant changes of bicarbonate and SaO2 were noted in each group
CONCLUSION
From above results, it would be advisable to analyze the sample in a short period of time or to store in a refrigerator when the measuring will be delayed. So we highly recommend that blood gas analysis should be performed as soon as possible after sampling, especially within 10 minutes.

MeSH Terms

Blood Gas Analysis
Electrodes
Hydrogen-Ion Concentration
Partial Pressure