A dusky color observed in a patient should prompt the therapist to consider which of the following tests?

A dusky color in a patient, which may indicate peripheral cyanosis or inadequate oxygenation, suggests that there could be an underlying issue affecting the patient's oxygen delivery or circulatory status. In this context, performing a complete blood count (CBC) is valuable because it can help identify conditions such as anemia or polycythemia, both of which can impact oxygen transport in the body. Anemia could lead to inadequate oxygen saturation even when the oxygen levels in the lungs are normal, while polycythemia may indicate a compensatory response to chronic hypoxia.

Other options may not address the immediate concern of oxygenation and the patient’s dusky appearance as effectively. Factors like pulmonary function tests, while essential for evaluating respiratory function, may not directly correlate with the color change observed. Echocardiography, while helpful for assessing heart function, does not provide immediate insight into the causes related to blood oxygen content. Measuring creatinine levels focuses on kidney function and would not directly relate to the patient's physical signs of dusky coloration.