Questions: Which patient finding indicates the need for home oxygen therapy? Heart rate 72 beats per minute Respiratory rate 24 breaths/min Arterial partial pressure (PaO2) of 50 mm Hg Serum carbon dioxide level 24 mEq / L

The answer is the third one: Arterial partial pressure (PaO₂) of 50 mm Hg.

Explanation for each option:

1. Heart rate 72 beats per minute: This is a normal heart rate for adults, typically ranging from 60 to 100 beats per minute. It does not indicate a need for home oxygen therapy.

2. Respiratory rate 24 breaths/min: While this is on the higher end of the normal range (12-20 breaths per minute for adults), it alone does not necessarily indicate a need for home oxygen therapy. It could be a sign of mild respiratory distress or anxiety, but further assessment would be needed.

3. Arterial partial pressure (PaO₂) of 50 mm Hg: This is a clear indicator for the need for home oxygen therapy. Normal PaO₂ levels are typically between 75 and 100 mm Hg. A PaO₂ of 50 mm Hg suggests significant hypoxemia, which is a strong indication for supplemental oxygen.

4. Serum carbon dioxide level 24 mEq/L: This is within the normal range for serum bicarbonate (HCO₃⁻), which is typically 22-28 mEq/L. It does not indicate a need for home oxygen therapy.

In summary, the finding that indicates the need for home oxygen therapy is an arterial partial pressure (PaO₂) of 50 mm Hg, as it reflects significant hypoxemia.