The reference range for arterial pH measured at 37°C is which of the following?

The reference range for arterial pH measured at 37°C is which of the following?

• A. 7.28-7.34
• B. 7.33-7.37
• C. 7.35-7.45
• D. 7.45-7.50

Answer: (C)

Arterial pH is kept within a very narrow range by the body's buffering systems and ventilation. At 37°C, the accepted reference range for arterial blood is 7.35 to 7.45. This window reflects the balance between acidic carbon dioxide and basic bicarbonate; values below 7.35 indicate acidemia, while values above 7.45 indicate alkalemia. Other ranges fall outside normal arterial physiology, describing acidemia or alkalemia rather than a true normal arterial pH. Temperature standardization matters because pH shifts with temperature, so labs use 37°C to keep measurements comparable.

Arterial pH is kept within a very narrow range by the body's buffering systems and ventilation. At 37°C, the accepted reference range for arterial blood is 7.35 to 7.45. This window reflects the balance between acidic carbon dioxide and basic bicarbonate; values below 7.35 indicate acidemia, while values above 7.45 indicate alkalemia. Other ranges fall outside normal arterial physiology, describing acidemia or alkalemia rather than a true normal arterial pH. Temperature standardization matters because pH shifts with temperature, so labs use 37°C to keep measurements comparable.