Effects of Temperature and Time Delay on Arterial Blood Gas and Electrolyte Measurements
Panida Srisan MD*, Teerasak Udomsri MD**, Pravit Jetanachai MD*, Sorasak Lochindarat MD*, Wiboon Kanjanapattanakul MD*
Affiliation : * Department of Pediatrics, Queen Sirikit National Institute of Child Health, College of Medicine, Rangsit University, Bangkok, Thailand ** Department of Pediatrics, Krabi Hospital, Krabi, Thailand
Objective : To determine the changes in pH, PaO2, PaCO2 and Na, K, Cl in arterial blood samples stored at room temperature
or on ice, at 0, 15, 30, 45 and 60 minutes.
Material and Method: Arterial blood samples were collected in heparinized capillary tubes and stored at room temperature
(24-26°C) and on ice (0-4°C). ABG and electrolytes were measured at 0, 15, 30, 45 and 60 minute intervals.
Results : There were significant decreases in the pH, PaO2, Na, Cl and significant increases in PaCO2 and K over time in both
groups. The changes were greater and faster at room temperature. The significant decrease in pH over time was not found
until 30 minutes at room temperature and 45 minutes on ice. There were significant decreases in PaO2, concurrent with
significant increases in PaCO2 from 15 minutes onwards in both groups. Both Na and K exhibited a significant change
at 60 minutes in the room temperature group. Significant decreases of Cl over time were not found until 15 minutes at room
temperature, and 30 minutes on ice.
Conclusion : For ABG and electrolytes analysis, the blood sample should be analyzed within 15 minutes and be stored at
either room temperature or on ice.
Keywords : Arterial blood gas, pH, PaO2, PaCO2, Electrolytes
