Final answer:
A nurse should report a decreased platelet count in a postpartum client with preeclampsia, as it may signal a severe complication known as HELLP syndrome. Elevated blood pressure is a key feature of preeclampsia, and deviations in platelets or liver enzymes are critical to monitor.
Step-by-step explanation:
A nurse reviewing the medical record of a postpartum client with preeclampsia should be concerned about several lab results that may indicate worsening or complications of the condition. Of the options provided, decreased platelet count (b) is the lab result that is particularly concerning in a client with preeclampsia, as it could signify a complication called HELLP syndrome (Hemolysis, Elevated Liver enzymes, and Low Platelet count), which is a severe form of preeclampsia.
Preeclampsia itself is characterized by increased blood pressure and can lead to other abnormalities such as problems with kidney or liver function, and in this context, abnormally low levels of blood components such as platelets are noteworthy. A nurse should report any significant deviations in platelets, liver enzymes, or signs of hemolysis to the provider promptly.