1. Diana Escobar Azusa Pacific University

2. Authors: Thiele, Thomas, Kathleen Selleng, Sixten Selleng, Andreas Greinacher, &Tamam Bakchoul July 2013 Source: International Seminar of Hematology Database: MEDLINE

3.  Thrombocytopenia (TCP) is commonly defined as a platelet count of <150,000 plts, some apply the cut-off at <100,000 plts, and even further to <50,000plts in patients ◦ Platelet number alone is not definitive  Compare to the patient’s baseline & nadir  Analyze timing of decrease & overall trend  Also analyze a lack of rise in plt ct.

4. Common Causes

5. 1. Hemodilution 2. Increased platelet consumption ◦ Due to massive trauma, bleeding, sepsis, DIC 3. Decreased platelet production 4. Increased platelet sequestration 5. Platelet destruction by immune mechanisms  Pseudothombocytopenina: “Idiopathic” ◦ develops in 2.5% of pts taking grycoprotein Iib/IIIa antagonists: abciximab, integrilin, tirofiban  Dx: repeated blood counts in citrated or heparinized blood

6.  In order to correctly identify, nurses must be familiar with the “normal” platelet trends in ICU patients with differing conditions. ◦ i.e.: trauma, major/minor surgery, medical.  Postsurgical: Expected Plt ct. decline between D1-D4 ◦ Magnitude reflects the extent of tissue trauma/blood loss  Plt. Consumption ◦ Should reach pre-surgery level between D5-D7, peak at D14

7.  *Post-Trauma: Critically injured pts: almost normal Plt cts at admission w/ rapid Plt decrease during first hrs ◦ *Plt ct <50,000 &/or delay in Plt. Recovery  associated with high mortality  *Medical: Plt. ct depends on underlying disease ◦ Predisposing conditions: Sepsis, DIC, Renal Replacement Therapy, Extracorporeal circuits, Intravascular devices, Multi-organ Failure, & recent CPR  Recent study of 243 ICU Pts  In medical pts. Plt recovery expected w/in 5D (90%), with proper treatment of underlying disease  Higher morbidity/mortality is Plt recovery delayed >4D  Persistent TCP at D14  mortality rt of 66% vs. 16% with normal Plt ct. Median Plt increase expected in ICU pts of ~30 x 10 ∧ 9/ L/D in survivors

9.  Monitor closely the trends in Plt recovery and be alert for any sudden decrease after initial recovery  Acute TCP can result from: ◦ Sepsis, acute infection, acute leukemia, severe thromboembolism, intoxication: alcohol, drug side- effects  Be alert for: ◦ Rapid decrease w/in 24-48 hrs after several days in ICU w/out reason  Dx: Plt trends, baseline, nadir, plt specifics

10.  Trauma: concomitant treatment for hemodilution, hypothermia, loss of clotting factors and platelets, hyperfibrinolysis ◦ Early Plt transfusions w/RBCs for major trauma  DIC: Manage underlying conditions and causes, platelet transfusions only given in cases w/high risk for bleeding  Sepsis: correlated with adverse outcomes, but not a cause, therefore Tx underlying infection  Intoxication: ◦ Chronic Alcohol abuse due to Plt sequestration in spleen (splenomegaly)

11.  Intoxication… ◦ Drugs (Non-Immune Pathogenesis): adverse drug reactions in 20% hospital pts. (effects on megakaryocytes)  Study of 3,496 pts finds:  Histamine H2 Antagonists  Nonsteroidal anti-inflammatory drugs  Unfractionated heparin  Acetaminophen (3.4% pts), valproate, carbamazepine, phenobartital, phenytoin (1%pts) ◦ Herbals: take detailed Hx ◦ Venoms: activate clotting cascade ◦ Treatment: charcoal ingestions, dialysis, antidote administration, d/c medications

12.  Immune: Plt ct fall to <5,000 w/in 24-48hrs w/bleeding symptoms or if Plt ct decreases 50%+ in 2 nd week of Tx ◦ Immune mediated Drug-Induced Thrombocytopenia (DITP)  Dx: Need lab tests of drug-dependent antibodies  Tx: D/C drugs immediately  Most Common Drugs:  Vancomycin, Penicillin, trimethoprim/sulfamethozazole, ceftriaxone, ibuprofen, meirtazapine

13.  Drug: Heparin Induced TCP (HIT) ◦ Drug-mediated, prothromboric disorder b/c immunization against Plt. Factor 4  S/S: Plt ct fall >50% from the highest value after start of Heparin Tx and/or a new thrombosis occurring 5-14D after Tx ◦ Incidence of HIT is low in ICU according to study  N= 3.198 ICU pts w/ incidence confirmed in 0.5% pts  Dx depends on scoring results of: Thrombocytopenia, Timing, Thrombosis, & oThers (4Ts Test/HEP Test)  Tx: d/c heparin, use low molecular weight heparin delteparin, use non-heparin anticoagulants

14.  What are the 3 most common causes of TCP in ICU patients? A. HIT, sepsis, trauma B. Trauma, DIC, sepsis C. Trauma, surgery complications, sepsis D. Intoxication, trauma, Immune response

15.  What are the three most common causes of TCP in ICU patients? A. HIP, sepsis, trauma B. Trauma, DIC, sepsis C. Trauma, surgery complications, sepsis D. Intoxication, trauma, Immune response

16.  True or False: Platelet transfusion is the first line treatment for patients with Thrombocytopenia

17.  False, first line treatment should be to target and treat underlying disease, platelet transfusions are only indicated bleeding patients or invasive procedures

18. Thiele, T., Selleng, K., Selleng, S., Greinacher, A., & Bakchoul, T. (2013). Thrombocytopenia in the intensive care unit-diagnostic approach and management. Seminars In Hematology, 50(3), 239-250. doi:10.1053/j.seminhematol.2013.06.008