Evaluation of neutrophil/lymphocyte and platelet/lymphocyte ratios in the differential diagnosis of decompensated heart failure and pneumonia in patients presenting to the emergency department with shortness of breath

SUMMARY Evaluation of Neutrophil/Lymphocyte and Platelet/Lymphocyte Ratios in the Differential Diagnosis of Decompensated Heart Failure and Pneumonia in Patients Presenting to the Emergency Department with Shortness of Breath Introduction: Shortness of breath is an important reason for emergency department's visits. Decompensated heart failure and pneumonia are the most common causes of shortness of breath. The hemogram is a test in which we can see neutrophil, lymphocyte and platelet values, which is inexpensive and frequently studied in dyspnea patients. Neutrophil / Lymphocyte ratio (NLR) and Platelet / Lymphocyte ratio (PLR) are start have been used as new biomarkers of many diseases in recent years. The values of these ratios were investigate in the diagnostic evaluation and prognosis of patients with dyspnea, although the high rates of these rates were associated with poor survival and poor prognosis. However, their value in differential diagnosis has not yet fully known. In our study, we planned to investigate the value of NLR and PLR in the differential diagnosis of pneumonia and decompensated heart failure in patients presenting to the emergency department with shortness of breath. In addition, the relationship of these rates to hospitalization or discharge decision, poor clinical course and short term mortality was evaluated. Materials and Method: Patients who presented to the adult emergency department of Dokuz Eylul University Hospital between Jan 1,2017 and Jan 1, 2018 with the complaint of "shortness of breath" were evaluate. Patients who are considered to have an initial diagnosis of pneumonia and / or decompensated heart failure are included in the study; patients with other etiological causes causing dyspnea and meeting exclusion criteria were not included in the study. Patients' age, gender, comorbid diseases, vital signs, hemogram parameters, blood gas analysis, NLR and PLR, if any biochemical parameters studied were screened retrospectively. NLR and PLR values were compare between patients diagnosed with pneumonia and patients diagnosed with decompensated heart failure for differential diagnosis. In the group diagnosed with pneumonia and in the group diagnosed with decompensated heart failure, it was investigate whether NLR and PLR values were effective in patients' hospitalization or discharge decision. Patients' need for mechanical ventilation support, inotropic drug requirements or presence of hypoxia were accept as the criteria of poor clinical course. The value of NLR and PLR in predicting poor clinical course and short term mortality was examined. The results were present with a p value of 95% confidence interval (CI) for each variable. Statistical significance level was determined as p <0.05. Results: One hundred ninety-six patients were included in the study. 54.1% of the patients are women; the average age is 76.2; 84% of patients were 65 years old or older. NLR, PLR, neutrophil and CRP values in patients with pneumonia were significantly higher than patients with decompensated heart failure. (NLR 7,57 vs. 4,97 p <0.001; PLR 212,3 vs. 156,0 p = 0.04; neutrophil 9,45 vs. 7,75 p<0,001; CRP 102,2 vs. 15,3 p<0,001). NLR had higher significance than PLR (For NLR, p <0.001, while for PLR, p = 0.04). For patients diagnosed with pneumonia, the sensitivity of NLR values greater than 5.36 is 72.7% and selectivity is 57.4%; for values greater than PLR 211.95, sensitivity was 51.1% and selectivity was 69.4%. While CRP has the highest diagnostic efficacy in pneumonia patients, NLR is in the second place and neutrophil value in the third place (AUC: 0.825 for CRP; AUC: 0.656 for neutrophil, AUC: 0.6679 for NLR). It was significant that only patients with pneumonia had high NLR and PLR when they were hospitalized or discharged. NLR and PLR values did not have a significant result in showing mortality (1st day, 14th day, 28th days). Although high NLR and PLR was significant in showing the presence of hypoxia, which is one of the poor clinical course, in patients diagnosed with pneumonia (Those with and without hypoxia are for NLR 13.5 vs. 6.4 p = 0.001; for PLR 171.9 vs. 229.6 p = 0.036), it was not significant in showing the need for mechanical ventilators and inotropes, which are other poor clinical course (p> 0.05). In addition, NLR and PLR were not significant in showing poor clinical course in patients diagnosed with decompensated heart failure. Conclusion: Although NLR and PLR values of patients with diagnosed pneumonia were significantly higher than patients with diagnosed decompensated heart failure, evaluation together with CRP levels is more acceptable for differential diagnosis of patients presented to the emergency department with shortness of breath. While the high NLR and PLR values were only significant in predicting hypoxia with pneumonia, were not significant for predicting mortality and hospitalization needs in in both patient groups. Key words: shortness of breath, emergency department, neutrophil lymphocyte ratio, platelet lymphocyte ratio, pneumonia, decompensated heart failure