3.10 Thrombocytopenia
Thrombocytopenia is characterized by a decreased number of platelets in the blood. Thrombocytopenia may occur due to many factors affecting platelet production, platelet destruction, or platelet utilization.
Thrombocytopenia is often an acquired condition, such as an immune-mediated response, response to another condition, or a side effect of medication. For example, idiopathic thrombocytopenic purpura (ITP) is an acquired thrombocytopenia caused by the client’s immune system mistakenly destroying its own platelets. Thrombocytopenia may be caused by other hematological disorders, such as aplastic anemia or leukemia. Additionally, medications such as aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), penicillin, phenothiazines, prednisone, and chemotherapy can cause thrombocytopenia.[1]
Thrombocytopenia can also be inherited due to genetic mutations, resulting in abnormal platelet production and function. Inherited forms of thrombocytopenia are more rare than acquired forms of the disease.[2],[3]
Thrombocytopenia can cause many symptoms related to excessive bleeding, such as easy bruising, petechiae, purpura, ecchymoses, prolonged bleeding from minor cuts or injuries, and excessive bleeding from the nose or gums. Purpura are red or purple spots on the skin that do not blanch when pressure is applied and measure between 4 and 10 millimeters (mm) in diameter. When purpura spots are less than 4 mm in diameter, they are called petechiae.[4] See Figure 3.10[5] for an image of a severe case of petechiae and purpura. In severe cases of thrombocytopenia, internal bleeding can occur, posing life-threatening risks.[6],[7]
Assessment
Physical Examination
Common signs and symptoms of thrombocytopenia are summarized in Table 3.10.
Table 3.10. Clinical Manifestations of Thrombocytopenia[8],[9]
| Body System | Clinical Manifestations |
|---|---|
| Integumentary | Easy bruising or purpura (purple or red spots on skin), petechiae (small red or purple dots on the skin), prolonged bleeding from cuts or injuries, or excessive bleeding from the gums or nose. |
| Musculoskeletal | Joint pain and swelling caused by hemarthrosis (bleeding into joints). |
| Gastrointestinal | Blood in the stool or black, tarry stools. |
| Genitourinary | Blood in the urine or heavy menstrual bleeding. |
| Respiratory | Hemoptysis (coughing up blood). |
| Neurological | Intracranial hemorrhage (rare). |
| Cardiovascular | Tachycardia, hypotension, and weak pulses resulting from blood loss. |
Diagnostic Testing
Thrombocytopenia is diagnosed by decreased platelet counts on a CBC. Bleeding times may be further evaluated by PT, PTT, and INR. Review normal reference ranges for common diagnostic tests in “Appendix A – Normal Reference Ranges.”
The structure of the platelets may also be examined through a test called a peripheral blood smear. If the cause of thrombocytopenia remains uncertain, a bone marrow aspiration and biopsy may be performed to assess the amount of