Which temperature is recommended for ABG samples if analysis is delayed beyond immediate collection?

• A. 20-25°C
• B. 2-8°C
• C. -20°C
• D. 37°C

Answer: (B)

Preserving ABG sample accuracy relies on slowing down cellular activity after collection. If analysis is delayed, cells in the sample keep metabolizing, which changes gas tensions and pH. Cooling the specimen to 2-8°C slows this metabolism, helping to maintain the true pH and gas values until testing. Room temperature would allow ongoing changes, and freezing (-20°C) would disrupt the sample in ways that invalidate the measurements. Heating to body temperature would speed up the drift even more. Therefore, refrigerating the sample at 2-8°C (often on ice) is the recommended approach when immediate analysis isn’t possible.