Which factor can contribute to hypoventilation leading to hypercapnia?

Hypoventilation occurs when there is inadequate ventilation to expel carbon dioxide (CO2) from the body, leading to an accumulation of CO2 in the bloodstream, known as hypercapnia. A key factor that contributes to hypoventilation is the lack of patient-driven breaths. Under normal circumstances, a patient’s respiratory drive is guided by their metabolic needs, which include factors such as activity level, carbon dioxide levels, and the presence of acidosis.

When a patient cannot initiate or sustain their own breathing—such as during sedation or anesthesia—this lack of patient-driven breaths means that the body's natural mechanism for expelling CO2 is diminished. As a result, the carbon dioxide levels can rise, leading to hypercapnia. In this context, the inability to take sufficient breaths to match the body's metabolic demands is a primary cause of hypoventilation.

The other options revolve around the mechanics of ventilation and oxygenation but do not directly contribute to hypoventilation in the same way. For instance, excessive tidal volume administration may lead to ventilation/perfusion mismatches or barotrauma, but it does not inherently signify that hypoventilation is occurring. Increased respiratory drive typically leads to increased ventilation rather than hypoventilation,