Final answer:
The nurse's priority when caring for an HIV-positive patient is the CD4 T-cell count, as it is the primary indicator of the patient's immune system status and progression of HIV.
Step-by-step explanation:
When caring for a client who has HIV, the nurse's priority laboratory value to consider is the CD4 T-cell count. This count is crucial as it provides a direct indicator of the patient's immune system function. Specifically, CD4 T cells, also known as T helper cells, play a vital role in the immune response.
The progression of HIV is typically tracked through three stages based on CD4 T-cell counts and the presence of clinical symptoms. When a patient's CD4 T-cell count falls below 500 cells/µL, it is cause for concern and may necessitate a change in treatment. A count below 200 cells/µL is diagnostic for AIDS, the most advanced stage of HIV infection, where the immune system is severely compromised and opportunistic infections are more likely to occur.
While other laboratory values such as White blood cell (WBC) count, Blood glucose level, and Serum potassium level also provide useful health information, they are not as directly linked to the progression of HIV as the CD4 T-cell count. An adequate CD4 T-cell count is essential for the body to mount an effective immune response though, and a decline below a certain threshold indicates a risk for immunodeficiency and opportunistic infections in HIV patients.