Which of the following is MOST characteristic of adequate breathing in an adult?

• A. 12 breaths/min with unilateral movement
• B. 20 breaths/min and bilateral chest movement
• C. 28 breaths/min with shallow breaths
• D. 16 breaths/min with chest retraction

Answer: (B)

Adequate breathing means the patient is ventilating well with a normal rate, comfortable depth, regular rhythm, and symmetric chest movement. In adults, a typical rate falls around 12–20 breaths per minute, and the chest should rise evenly on both sides with each breath, indicating good tidal volume and efficient ventilation.

The choice describing 20 breaths per minute with bilateral chest movement fits best because it shows a normal rate within the expected range and symmetric chest expansion, signaling that both lungs are contributing to ventilation and the tidal volume is likely adequate.

The other scenarios suggest problems: 12 breaths per minute but with unilateral movement implies one side isn’t ventilating properly, which is not adequate. 28 breaths per minute with shallow breaths shows rapid, under-ventilated breathing, risking poor gas exchange. 16 breaths per minute with chest retraction indicates increased work of breathing and possible distress, not true adequacy.