From the Guidelines
Low platelet levels (thrombocytopenia) in emergency medicine should be concerning when the count falls below 10 × 10^9 cells/L, as this is the threshold for prophylactic platelet transfusion to reduce the risk of spontaneous bleeding, according to the AABB guidelines 1.
Key Considerations
- The AABB recommends transfusing hospitalized adult patients with a platelet count of 10 × 10^9 cells/L or less to reduce the risk for spontaneous bleeding 1.
- For patients undergoing elective central venous catheter placement, a platelet count of less than 20 × 10^9 cells/L is considered a threshold for prophylactic platelet transfusion 1.
- A platelet count of less than 50 × 10^9 cells/L is suggested as a threshold for prophylactic platelet transfusion in patients having elective diagnostic lumbar puncture or major elective nonneuraxial surgery 1.
Clinical Decision Making
When evaluating patients with low platelet levels, it is essential to consider the underlying cause of thrombocytopenia, the presence of bleeding or risk factors for bleeding, and the need for invasive procedures.
- The rate of platelet decline and associated symptoms like petechiae, purpura, mucosal bleeding, or altered mental status should also be taken into account.
- Certain medications, infections, and conditions like liver disease or leukemia can cause dangerous thrombocytopenia, and treatment should be tailored to the underlying cause.
Treatment
Treatment of thrombocytopenia may include stopping offending medications, administering corticosteroids, IVIG, or platelet transfusions, depending on the underlying cause and severity of the condition.
- Platelet transfusions are typically indicated for counts below 10 × 10^9 cells/L in stable patients, below 20 × 10^9 cells/L with bleeding risk factors, or below 50 × 10^9 cells/L with active bleeding or before invasive procedures 1.
From the Research
Concerning Levels of Platelets in Emergency Medicine
- A low level of platelets, also known as thrombocytopenia, is generally defined as a platelet count of less than 150 × 10^3 per μL 2.
- Patients with a platelet count greater than 50 × 10^3 per μL are generally asymptomatic, while those with platelet counts between 20 and 50 × 10^3 per μL may have mild skin manifestations such as petechiae, purpura, or ecchymosis 2.
- A platelet count of less than 10 × 10^3 per μL is considered concerning and indicates a high risk of serious bleeding 2.
- In emergency medicine, thrombocytopenia can be caused by various factors, including decreased platelet production, increased destruction, splenic sequestration, or dilution or clumping 2.
Emergency Hospitalization for Thrombocytopenia
- Certain causes of thrombocytopenia, such as heparin-induced thrombocytopenia, thrombotic microangiopathies, and the hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome, require emergency hospitalization 2.
- Patients with acute thrombocytopenia may also require hospitalization, and transfusion of platelets is recommended when patients have active hemorrhage or when platelet counts are less than 10 × 10^3 per μL 2.
Management of Thrombocytopenia
- Desmopressin may be a useful agent to reduce bleeding and transfusion requirements for people with platelet dysfunction or with a history of recent antiplatelet drug administration undergoing cardiac surgery 3.
- In patients with severe traumatic brain injury and platelet dysfunction, desmopressin may be an alternative to platelet transfusions to correct platelet dysfunction 4.
- The use of platelet transfusions, desmopressin, and other strategies to reverse the effects of antiplatelet agents in the setting of intracranial hemorrhage is still being studied, and more research is needed to determine the most effective approach 5.