Incidence and risk factors for thrombocytopenia in the intensive care units of a tertiary hospital in northern India

Abstract

Background. In Western countries, incidence of thrombocytopenia in intensive care units (ICUs) has been found to be 13 - 44%. We chose to study the incidence, risk factors and transfusion requirements of thrombocytopenia in tertiary care ICUs in northern India. Objective. To study the incidence and risk factors of thrombocytopenia in a mixed ICU. Methods. This prospective observational 6-month cohort study was conducted in two 22-bedded medical-surgical ICUs. Patients aged 18 years or older with an ICU stay of at least 2 days were included. Results. Thrombocytopenia (<150 000/dL) occurred in 190 (38%) of the 500 patients studied. Thrombocytopenia was present on admission in 41 (8%) patients. Of the remaining patients, 149 (32%) developed new-onset thrombocytopenia (NOT) – thrombocytopenia developing in patients with platelet count more than 150 000/U on admission – during ICU stay. Incidence and prevalence were 30% and 38%, respectively. ICU mortality was 13%. Thrombocytopenia was commonly associated with sepsis, disseminated intravascular coagulation, heparin and certain antibiotics. Cause could not be established in 10 patients. Underlying coronary artery disease and sepsis correlated with thrombocytopenia. Mortality was higher in patients with NOT (15.4 v. 8.7%, p=0.003). Compared with non-thrombocytopenic patients, patients with NOT required more blood product transfusions (57.7 v. 38.4%, p=0.000) and mechanical ventilation (23.5 v. 13.5%, p=0.008). No difference was observed in length of hospital stay and bleeding risk between the two groups. Conclusion. We found incidence and prevalence of thrombocytopenia in the ICU comparable with internationally reported figures. NOT was associated with higher mortality and morbidity and may be considered as a marker of disease severity.