Thrombocytopenia and platelet transfusion in UK critical care: a multicenter observational study

BACKGROUND: Platelet (PLT) transfusions are widely used, but few studies have described patterns of use in critical care. STUDY DESIGN AND METHODS: As part of a prospective multicenter observational study of all sequentially admitted patients to UK general intensive care units (ICUs) over 8 weeks, daily data were collected throughout admission on frequency of thrombocytopenia and use of PLT transfusions, in addition to clinical outcomes, including bleeding. RESULTS: There were 1923 admissions recruited across 29 ICUs for analysis (96.6% of all eligible admissions). The period prevalences of severe thrombocytopenia (<50x109/L) for the entire ICU stay were 12.4% (234/1881) and 13.7% (263/1914) when the 24 hours before admission was also included. A total of 35.4% of patients who experienced severe thrombocytopenia died in the ICU. A total of 169 patients (9% of study population) received 534 units of transfused PLTs (median number of units per patient admission was 2; interquartile range, 1-3; maximum, 38). Pretransfusion PLT counts were more than 50x109 for 40% of PLT transfusions overall, and even when no clinically significant bleeding was recorded on the day of transfusion, the lowest recorded PLT count was more than 50x109 for 34% of transfusions. There was evidence of only modest increments in PLT count. CONCLUSION: Thrombocytopenia is common in critical care, but there is wide variation in PLT transfusion use. Patients commonly received PLT transfusions on days without clinically significant hemorrhage. The high prevalence of thrombocytopenia in the critically ill population and inconsistent patterns of PLT transfusions indicate the importance of improving the evidence base for PLT use.