To prevent deep vein thromboses following knee replacement surgery, an adult male client is receiving daily subcutaneous enoxaparin. Which laboratory result requires immediate action by the nurse?

Reference Range:
Hematocrit [42% to 52% (0.42 to 0.52 volume fraction)]
Platelets [150,000 to 400,000/mm² (150 to 400 × 10^9/L)]
Creatinine [0.5 to 1.1 mg/dL (44 to 97 μmol/L)]
Blood Urea Nitrogen (BUN) [10 to 20 mg/dL (3.6 to 7.1 mmol/L)]

Choice A reason: Eliminating use of nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, is an instruction that the nurse should provide to the client who is taking lithium carbonate, which is a medication that stabilizes mood and prevents manic episodes. NSAIDs can increase the blood levels of lithium and cause toxicity, which can manifest as nausea, vomiting, tremors, confusion, or seizures.

Choice B reason: Monitoring blood glucose levels daily is not an instruction that the nurse should provide to the client who is taking lithium carbonate, which is a medication that does not affect the blood sugar levels or the risk of diabetes. Blood glucose levels may be important for the general health of the client, but they are not related to lithium therapy.

Choice C reason: Notifying healthcare provider prior to dental procedures is not an instruction that the nurse should provide to the client who is taking lithium carbonate, which is a medication that does not interact with local anesthetics or antibiotics that may be used during dental procedures. However, the client should inform the dentist about their medical history and medications, as a precaution.

Choice D reason: Avoiding consuming all foods that contain iodine is not an instruction that the nurse should provide to the client who is taking lithium carbonate, which is a medication that does not interfere with the thyroid function or the metabolism of iodine. Iodine is an essential nutrient that is found in many foods, such as seafood, dairy products, eggs, and iodized salt. Avoiding iodine can cause deficiency and lead to goiter or hypothyroidism.

Choice A reason: Platelet count of 100,000/mm³ (100 x 10^9/L) is below the normal range and indicates thrombocytopenia, which is a decrease in the number of platelets in the blood. Thrombocytopenia can increase the risk of bleeding and bruising, and can be a serious adverse effect of enoxaparin. This laboratory result requires immediate action by the nurse, such as notifying the prescriber, monitoring for signs of bleeding, and withholding the next dose of enoxaparin.

Choice B reason: Hematocrit 45% (0.45 volume fraction) is within the normal range and does not indicate any problem with the client's red blood cells or oxygen-carrying capacity.

Choice C reason: Blood urea nitrogen (BUN) 20 mg/dL (7.1 mmol/L) is within the normal range and does not indicate any problem with the client's kidney function or hydration status.

Choice D reason: Serum creatinine 1.0 mg/dL (88.4 μmol/L) is within the normal range and does not indicate any problem with the client's kidney function or muscle metabolism.