Which clinical finding most indicates a serious complication in a client receiving chemotherapy?

Decreased urine output is a significant clinical finding that often indicates a serious complication in a client receiving chemotherapy. This symptom can suggest acute kidney injury or renal complications, which can arise due to the nephrotoxic effects of certain chemotherapeutic agents, dehydration, or tumor lysis syndrome. When a patient has decreased urine output, it raises the concern for potential electrolyte imbalances and fluid overload, which necessitates immediate medical evaluation and intervention.

In contrast, elevated white blood cell count may not always indicate a serious complication in a patient undergoing chemotherapy. This could be a physiological response to infection or stem cell recovery, rather than a direct consequence of chemotherapy itself. Fatigue and malaise are commonly experienced side effects of chemotherapy and do not necessarily point to a serious complication. Hair loss, while distressing, is also a common and expected side effect of many chemotherapy regimens and does not indicate an immediate threat to the patient's health. Therefore, recognizing decreased urine output as an indicator of potential complications can help ensure prompt and effective management of the patient's condition.