Utility of Platelet Indices as a Predictive Marker in Sepsis: An Observational Study From North East India

Background Unraveling sepsis remains the holy grail of clinical medicine and the commonest cause of in-hospital mortality worldwide. Various newer biomarkers have emerged in recent years that aid in the diagnosis and prognostication of sepsis. However, the widespread use of these is limited by availability, cost, and long turnaround times. Considering the crucial role of hematological parameters in infectious conditions, the present study aimed to evaluate the association of various platelet indices with the severity and outcomes in patients diagnosed with sepsis. Methods This was a single-center, prospective, observational study comprising 100 consecutive patients who fulfilled the selection criteria in the emergency department of a tertiary care hospital from June 2021 to May 2022. All patients underwent history taking, physical examination, and necessary laboratory investigations, including complete blood counts, biochemistry panel, and radiographic and microbiological tests. A detailed assessment of various platelet indices (platelet count, mean platelet volume, and platelet distribution width) was performed, and its association with outcomes was derived. The Sequential Organ Failure Assessment (SOFA) score was recorded for all patients. Results The majority of the study population was male (52%) with a mean age of 48.05±19.27 years. Respiratory infection (38%) was the most common origin of sepsis followed by genitourinary infections in 27%. The mean platelet count on admission was 1.83±1.21 lakhs/mm(3). The incidence of thrombocytopenia (<1.5 lakhs/ mm(3)) in our study sample was 35%. The overall in-hospital mortality of the study group was 30%. Thrombocytopenia was significantly associated with a higher SOFA score (7.4±3 vs. 3.7±1.9, P<0.05), longer hospital stays (10.8±4.6 vs. 7.8±3.9; p<0.05), and mortality (17 vs. 13; p<0.05). The change in platelet count, platelet distribution width, and mean platelet volume from Day 1 to Day 3 also correlated with outcomes. There was a decrease in platelet count among the non-survivors compared to an increase in platelet count among survivors from Day 1 to Day 3 (p<0.05). Similarly, the change in platelet distribution width showed a decreasing trend among the survivors compared to an increasing trend among the non-survivors (p<0.05). The mean platelet volume of non-survivors increased from Day 1 to Day 3 compared to a downward trend among the survivors (p<0.05). Conclusion Septic patients with thrombocytopenia on admission had a higher SOFA score and were associated with worse outcomes. Additionally, platelet indices, such as platelet distribution width and mean platelet volume, serve as important prognostic markers among sepsis patients. Change in these parameters from Day 1 to Day 3 also correlated with outcomes. These indices are simple and affordable, allowing for their serial assessment to aid in the prognosis of sepsis.