The importance of laboratory tests and Body Mass Index in the diagnosis of acute appendicitis.

<b>Background:</b> Acute appendicitis is the most common cause of acute abdomen. Delay in diagnosis increases the mortality and morbidity. <br><b>Aim: </b>In this study, we aimed to investigate whether the body mass index is useful in diagnosis and whether the neutrophil /lymphocyte and platelet/lymphocyte ratios can help in determining the inflammation level of acute appendicitis. <br><b>Meterial and Methods:</b> Cases of appendectomy performed between June 2012 and December 2018 in our clinic were analyzed retrospectively. Based on the pathology results of the cases included in the study, 4 groups were formed, i.e.: Group 1 (initial stage), Group 2 (catarrhal stage), Group 3 (phlegmonous-gangrenous stage) and Group 4 (perforation). The study compared age, body mass index, leukocyte values, red cell distribution width (RDW), neutrophil/lymphocyte ratio (NLR), platelet /lymphocyte ratio (PLR), and mean platelet volume (MPV) between groups. <br><b> Results:</b> 828 cases were included in the study. When compared between groups, the values of Group 3 and Group 4 were higher than those of Group 1 and Group 2 for PLR and NLR. There was no difference in RDW and MPV values in the blood. When Body Mass Index (BMI) was compared between groups, it was found to be significantly higher with increasing histopathological stage. <br><b>Conclusion:</b> In acute appendicitis, the blood leukocyte value, elevated PLR and NLR are helpful in diagnosis. We aimed to emphasize that the diagnosis of acute appendicitis is delayed in patients with a BMI above 30 and/or at age of over 40 years, with the perforation rate being determined more frequently.