The role of initial platelet-to-lymphocyte ratio and lactate level in the emergency department in predicting mortality from sepsis and septic shock in patients older than 65 years

Sepsis is a disease that can be mortal and costly to treat. The disease is especially common among elderly patients. In this study, we investigated the role of platelet-lymphocyte ratio and lactate levels measured in the emergency department for predicting the mortality from sepsis in patients older than 65 years. We enrolled 131 patients who were older than 65 and diagnosed with sepsis and septic shock in the emergency department of Baskent University Ankara Hospital between 1 August 2014 and 1 August 2016. We used the patient information management system and patient files archive information to obtain information about these patients' demographic information, comorbid diseases, admission hemodynamic parameters, emergency department interventions (e.g., fluid replacement, vasopressor administration, blood transfusion, steroid use, and antibiotherapy), mechanical ventilation status, and cardiopulmoner resuscitation needs. We also obtained information about their 30 days' mortality from the Central Demographics Management System. We detected a statistically significant difference between systolic and diastolic blood pressures (p = 0.045 and p = 0.002, respectively), Glasgow Coma Scale (p < 0.001), and blood urea nitrogen (p < 0.001) of the groups with and without mortality by 30 days. Respiration rate (p = 0.503), fever (p = 0.588), pulse oxygen saturation (p = 0.172), creatinine (p = 0.082), hemoglobin (p = 0.541), mean platelet volume (p = 0.593), lymphocyte (p = 0.478), platelet-lymphocyte ratio (PLR) (p = 0.821), and lactate levels (p = 0.120) were not statistically significant. We also revealed a statistically significant difference (p = 0.001) between the two groups with respect to the quick Sepsis Related Organ Failure Assessment (qSOFA) scores. We detected a positive correlation between the mortality and qSOFA (r=0.321, p<0.05). However, qSOFA was not an independent predictor of mortality in logistic regression analysis. In conclusion, we suggest that further studies of PLR are required to predict mortality in this patient population. Although lactate levels were higher in the mortality group, the difference was not significantly different. Under the light of data from previous studies, we suggest that continuous monitoring of lactate levels, as compared to an initial single measurement of lactate level, would provide clinicians with more relevant information about short term mortality.