Thrombocytopenia: A Risk Factor of Mortality for Patients with Sepsis in the Intensive Care Unit

Objectives: The objective of this study was to evaluate the intensive care unit (ICU) and long-term mortality in sepsis patients with/without thrombocytopenia on the fifth day of ICU admission.

Materials and methods: The retrospective observational cohort study was performed in a teaching hospital, and patients with sepsis who stayed more than 4 days in the ICU between January 2012 and December 2012 were included. Patients were divided into two groups according to thier platelet count at fifth day of ICU stay: Group 1, < 150.000/μL; Group 2, >150.000/μL. Patients having thrombocytopenia on admission were excluded. The patients' characteristics, comorbid diseases, body mass index, arterial blood gas analysis and blood biochemistry results, SIRS criteria, Acute Physiological and Chronic Health Evaluation Score II (APACHE II), implication of invasive and non-invasive mechanical ventilation, use of sedation, nutrition information, and culture results of microbiological samples were recorded. The groups were compared according to the recorded data. Logistic regression analysis was performed for ICU mortality; the Kaplan-Meier test was used to evaluate 12-month survival after ICU discharge.

Results: During the period, 1003 patients were admitted to the ICU; 307 sepsis patients were included in the study. Group 1 (n= 67) and Group 2 (n=240) had similar patient characteristics and sepsis findings. The groups had similar ICU and hospital stays; mortality was higher in Group 1 than in Group 2 (40.3% vs. 17.5%, respectively, p< 0.001). Fifth day thrombocytopenia, septic shock, male gender, and low albumin levels were found to be risk factors of ICU mortality; the respective odds ratios, 95% confidence intervals, and p values for these factors were 3.03, [1.15-7.45], p= 0.025; 4.97, [1.79-13.86], p= 0.002; 3.61, [1.27-10.23], p= 0.001; and 0.19, [0.07-0.52], p= 0.001. Follow-up after a year indicated that 124 out of 238 (52.1%) patients died, and 50% of the deaths occurred in the first 2 months. Kaplan-Meier analysis revealed no statistically significant effects of thrombocytopenia at ICU day 5 on 12-month mortality after ICU discharge.

Conclusion: Higher rates of septic shock and mortality were seen in sepsis patients with thrombocytopenia in the ICU. The measurement of thrombocytopenia in the ICU, which is easy and low-cost, may help to predict mortality. Thus, precautions can be taken early in patient treatment and follow-up. As we know, early intervention is crucial in the approach to sepsis.