Which assessment finding indicates to the practical nurse that a Venturi face mask is producing the desired effect?

A. Increased oxygen saturation indicates that the Venturi face mask is effectively delivering the specified concentration of oxygen. This is the primary goal of using a Venturi mask, which provides precise oxygen delivery to improve oxygen saturation levels. B. Increased cough productivity is not a direct indicator of the effectiveness of a Venturi face mask. The mask's purpose is to deliver oxygen, not to alter cough patterns. C. Decreased cough frequency is unrelated to the function of the Venturi face mask. The mask's effectiveness is measured by oxygen delivery rather than changes in cough frequency. D. Decreased breath sounds are not a direct measure of the effectiveness of a Venturi face mask. Breath sounds could indicate other respiratory issues but do not specifically reflect the effectiveness of oxygen therapy.