Final answer:
In a client with COPD exacerbation due to a respiratory infection, a decreased forced expiratory flow is expected, signifying airway obstruction and increased flow resistance, which is a typical finding on spirometry.
Step-by-step explanation:
The nurse assessing the respiratory status of a client experiencing an exacerbation of COPD secondary to a respiratory infection will expect to find a decreased forced expiratory flow (FEF). This is indicative of an obstruction in the airways common in COPD, which can be aggravated by a respiratory infection. The forced expiratory volume (FEV), measured over one second (FEV1), tends to reduce in such conditions, and the FEV1/FVC (forced vital capacity) ratio is also decreased, as patients have difficulty exhaling air quickly due to increased resistance in the lungs. Conversely, a high FEV1/FVC ratio is indicative of stiff, poorly compliant lungs, such as with lung fibrosis, where the lungs exhale most of their volume very quickly but have a reduced size.
Lung volumes are measured through spirometry, which includes the measurement of forced expiratory volume (FEV) and forced vital capacity (FVC). The FEV1/FVC ratio is used to diagnose lung diseases such as asthma, emphysema, and fibrosis. If the ratio is high, it indicates lung fibrosis, which makes the lungs less pliable and decreases their size. On the other hand, if the ratio is low, it indicates resistance in the lungs, which is characteristic of asthma and makes it difficult for the patient to exhale the air.