A nurse is caring for a client who is postoperative. The nurse should recognize that which of the following methods is the most reliable source when determining the intensity of the client's pain?

A. Urinary retention can lead to an increased risk of urinary tract infections. When urine remains in the bladder for prolonged periods, it can become a breeding ground for bacteria, increasing the likelihood of infection.
B. While bladder outlet obstruction can lead to urinary retention, this is more of a potential cause rather than a complication to monitor. In an immobile client, it may not be the primary concern unless there are specific signs or known conditions that suggest obstruction.
C. Proteinuria (presence of protein in the urine) is typically associated with kidney damage or disease, rather than urinary retention itself. While kidney function should always be monitored in any patient, protein in the urine is not a direct consequence of urinary retention or immobility.
D. Neurogenic bladder refers to bladder dysfunction due to nerve problems, affecting the ability to sense fullness or control urination. While this can be a concern for clients with certain neurological conditions, it is not an immediate monitoring concern for a client experiencing urinary retention solely due to immobility.

A. This statement pertains to the client's current state but does not represent an intervention taken by the nurse. It would be more appropriate for documentation in a narrative or assessment section rather than the intervention component.
B. This entry describes an outcome or finding related to the client’s condition rather than an intervention. While it is important data, it does not reflect an action taken by the nurse and thus would not be included in the intervention section.
C. It clearly describes a specific action taken by the nurse (administering medication) in response to the problem (nausea and vomiting). It directly addresses the client's needs and reflects an intervention aimed at treating the identified problem.
D. This statement indicates the problem or symptom that the client is experiencing but does not describe an intervention. While it is critical information for understanding the client’s condition, it belongs in the problem or assessment section rather than the intervention component.