A client with chronic obstructive pulmonary disease (COPD) is admitted to the telemetry unit with severe pneumonia. Which assessment is most important for the nurse to obtain?

A client with pre-existing COPD and a new, severe respiratory infection like pneumonia is at high risk for hypoxemia. Hypoxemia can directly lead to cardiac dysrhythmias, which is a primary reason for admission to a telemetry unit where the heart rhythm is continuously monitored. Identifying a dysrhythmia is urgent as it can be life-threatening. While assessing the posterior lung fields (C) is relevant to pneumonia, the specific admission to telemetry indicates cardiac monitoring is the priority. Assessing short-term memory (B) or peripheral pulses (D) is less critical in this acute, potentially unstable situation.