Thrombocytopenia is common in critically ill patients and is associated with increased duration of hospital stay and higher mortality. While a moderate decline in platelet count does not present a serious risk to most patients, clinicians often intervene in an attempt to prevent life-threatening outcomes associated with severe thrombocytopenia, or thrombosis associated with heparin-induced thrombocytopenia (HIT). A wide range of potential causes of thrombocytopenia have been reported in the literature, but study results have been inconsistent making treatment decisions difficult.
To identify independent risk markers for thrombocytopenia in ICU patients at a teaching hospital. A secondary objective was to compare these risk markers to those identified in a previous study carried out at a community hospital ICU.
Fifteen bed Intensive Care Unit (ICU) in a teaching hospital.
Retrospective study involving 276 consecutive patients meeting inclusion criteria.
Main Outcome Measures
Univariate and multivariate logistic regression analyses were used to identify independent risk markers present on admission and throughout the ICU stay.
Thrombocytopenia developed in 54 (19.6%) patients. Independent risk markers included mechanical ventilation (odds ratio [OR], 11.1; 95% confidence interval [CI], 1.4-88.2; p=0.023), dobutamine (OR, 4.9; 95% CI, 2.2-11.2; p<0.001), packed red blood cell transfusions (OR, 2.5; 95% CI, 1.2-5.2; p=0.010), dopamine (OR, 2.0; 95% CI, 1.04-4.0; p=0.053) and APACHE II score (OR per 5 unit increase, 1.4; 95% CI, 1.1-1.7; p<0.001). Two variables were associated with a lower risk of thrombocytopenia: admission platelet count (OR per 50 x 109/L increase, 0.6; 95% CI, 0.5-0.8; p<0.001) and cefuroxime (OR, 0.4; 95% CI, 0.2-1.2; p=0.101). Three variables were common to both the teaching and community hospital models: admission platelet count, APACHE II score and the transfusion of packed red blood cells Heparin was not identified as a risk marker in either the teaching or community hospital population. In both populations, thrombocytopenia was associated with a greater mortality rate and longer hospital and ICU stays.
Risk markers for the development of thrombocytopenia in ICU patients at an academic hospital include mechanical ventilation, transfusions, admission platelet count, medications and APACHE II score. There is substantial overlap with risk markers identified at a community hospital setting.