Question

Fill in the blank: Wanda has now been on IV heparin therapy for 7 days. In addition to monitoring the aPTT, the nurse should very carefully be monitoring which other hematological laboratory value?

Short answer

The additional hematological laboratory value that the nurse should carefully monitor when a patient is on IV heparin therapy, apart from aPTT, is the Platelet count.

Step-by-step solution

Understanding the Effects of Heparin

Heparin acts as an anticoagulant by preventing the formation of clots and extension of existing clots within the blood. While effective, it may inadvertently cause excessive bleeding. Therefore, while aPTT is monitored to assess the patient's response to heparin treatment, other hematological laboratory values need to be monitored to detect any potential bleeding complications early.

Identifying the Hematological Laboratory Value to Monitor

When a patient is on heparin therapy, the other crucial hematological value to monitor, besides aPTT, is the Platelet count. Heparin can trigger an immune response leading to Heparin-induced Thrombocytopenia (HIT), a potentially serious condition where platelet levels in the blood fall drastically thereby increasing the risk of serious bleeding.

Key concepts

aPTT Monitoring

The activated Partial Thromboplastin Time (aPTT) test is a blood test that measures the effectiveness of the heparin therapy. When Wanda is on intravenous (IV) heparin, it is important to keep her blood from clotting too much or too little. The aPTT test helps ensure that the dose of heparin is just right.

aPTT results indicate how long it takes the blood to clot. For patients on heparin, aPTT levels usually need to be 1.5 to 2.5 times their normal value. If the aPTT value is too high, there's a risk of bleeding; if it's too low, clots may form. Therefore, aPTT monitoring is a critical element used by healthcare professionals to adjust heparin dosage for safety and efficacy.

Platelet Count

Platelets are tiny blood cells that help your body form clots to stop bleeding. In the context of heparin therapy, closely watching the platelet count is crucial. An abnormally low count, a condition known as thrombocytopenia, can signal that the patient is developing complications from the treatment.

For patients like Wanda, who are undergoing anticoagulant therapy, the platelet count is a key indicator of blood's ability to clot. The normal range of platelets is typically between 150,000 and 400,000 per microliter of blood. Should the count fall below this range, it could indicate a heightened risk of bleeding, requiring immediate medical attention and potentially an adjustment in heparin dosage or a switch to a different medication.

Heparin-induced Thrombocytopenia (HIT)

Heparin-induced Thrombocytopenia (HIT) is a serious immune-mediated adverse reaction to heparin therapy. HIT occurs when the body generates antibodies against heparin when it is bound to a protein called Platelet Factor 4 (PF4). These antibodies can activate platelets, leading to the formation of dangerous clots while decreasing circulating platelet levels, which paradoxically increases the risk of bleeding.

Symptoms of HIT may include unexplained drop in platelet count, new or worsening clots, or skin lesions at injection sites. If HIT is suspected, heparin must be discontinued, and alternative anticoagulants should be considered. Because HIT can be life-threatening, prompt detection and management are critical.