title: Thrombocytopenia and prognosis in intensive care.
abstract: OBJECTIVE
  To study the incidence and prognosis of thrombocytopenia in adult intensive care unit (ICU) patients.
  
  
  METHODS
  Prospective observational cohort study.
  
  
  METHODS
  The medical ICU of a university hospital and the combined medical-surgical ICU of a regional hospital.
  
  
  METHODS
  All patients consecutively admitted during a 5-month period.
  
  
  METHODS
  Patient surveillance and data collection.
  
  
  RESULTS
  The primary outcome measure was ICU mortality. Data of 329 patients were analyzed. Overall ICU mortality rate was 19.5%. A total of 136 patients (41.3%) had at least one platelet count <150 x 10(9)/L. These patients had higher Multiple Organ Dysfunction Score (MODS), Simplified Acute Physiology Score (SAPS) II, and Acute Physiology and Chronic Health Evaluation (APACHE) II scores at admission, longer ICU stay (8 [4-16] days vs. 5 [2-9] days) (median [interquartile range]), and higher ICU mortality (crude odds ratio [OR], 5.0; 95% confidence interval [CI], 2.7-9.1) and hospital mortality than patients with daily platelet counts >150 x 10(9)/L (p < .0005 for all comparisons). Bleeding incidence rose from 4.1% in nonthrombocytopenic patients to 21.4% in patients with minimal platelet counts between 101 x 10(9)/L and 149 x 10(9)/L (p = .0002) and to 52.6% in patients with minimal platelet counts <100 x 10(9)/L (p < .0001). In all quartiles of admission APACHE II and SAPS II scores, a nadir platelet count <150 x 10(9)/L was related with a substantially poorer vital prognosis. Similarly, a drop in platelet count to < or =50% of admission was associated with higher death rates (OR, 6.0; 95% CI, 3.0-12.0; p < .0001). In a logistic regression analysis with ICU mortality as the dependent variable, the occurrence of thrombocytopenia had more explanatory power than admission variables, including APACHE II, SAPS II, and MODS scores (adjusted OR, 4.2; 95% CI, 1.8-10.2).
  
  
  CONCLUSIONS
  Thrombocytopenia is common in ICUs and constitutes a simple and readily available risk marker for mortality, independent of and complementary to established severity of disease indices. Both a low nadir platelet count and a large fall of platelet count predict a poor vital outcome in adult ICU patients.
authors.affiliation: Department of Internal Medicine, University Hospitals, Leuven, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Vanderschueren
authors.forename: A
authors.initials: A
authors.lastname: De Weerdt
authors.forename: M
authors.initials: M
authors.lastname: Malbrain
authors.forename: D
authors.initials: D
authors.lastname: Vankersschaever
authors.forename: E
authors.initials: E
authors.lastname: Frans
authors.forename: A
authors.initials: A
authors.lastname: Wilmer
authors.forename: H
authors.initials: H
authors.lastname: Bobbaers
mesh_terms: D000368:Aged; D003422:Critical Care; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D013921:Thrombocytopenia / Q000150:complications / Q000453:epidemiology* / Q000209:etiology