The prognostic role of platelet to lymphocyte ratio and mean platelet volume in critically ill patients

OBJECTIVE: The aim of this study was to identify the relationship between complete blood count parameters, mean platelet volume (MPV), and platelet to lymphocyte ratio (PLR) with mortality and hospitalization duration in critically ill patients. PATIENTS AND METHODS: A retrospective analysis was made of patients admitted to our tertiary adult intensive Care Unit (ICU) between January 2015 and January 2016. Hemoglobin (Hb), white blood cell (WBC), lymphocyte and platelet counts were obtained from the complete blood count performed at the time of admission. MPV and PLR levels were calculated from these data. Other data were retrieved from the patient follow-up records. RESULTS: The investigation included a total of 306 patients. The total mortality rate was 40.2%. The initial median PLR level was 206.7 (8.1-1675.0) for non-survivor patients and 194.5 (12.8-1236.6) for survivor patients. The PLR level was higher in the non-survivor group, but there was no statistically significant difference between the groups (p>0.05). The median MPV level was 7.66 (5.17-15.25) for the survivors and 8.09 (4.36-16.19) for the non-survivors, and there was no statistically significant difference between the groups (p=0.237). The median length of stay (LOS) of all patients was 7 (2-61) days. Only the Acute Physiology and Chronic Health Evaluation (APACHE) II score was found to have a positive correlation with LOS (p<0.05). CONCLUSIONS: PLR has no effect on mortality rates regardless of whether the patient has thrombocytopenia or not at the time of admission. MPV levels have no significant relationship with mortality. Neither MPV nor PLR have an effect on LOS. The use of these as a prognostic factor for mortality in critically ill patients is still unclear.