The value of neutrophil-to-lymphocyte ratio in acute appendicitis

In acute appendicitis, neutrophil-to-lymphocyte ratio (NLR) values exceeding 8.8 are shown by some authors to predict the complexity of disease. Although attractive, NLR-based approach is not included in the general standards of appendicitis care. Our objective was to test this hypothesis by our data, and to determine if intraoperative findings correlated with NLR. In a retrospective observational study from September 2016 till August 2020, 242 consecutive cases of acute appendicitis were identified. Two groups of patients were defined by presence of uncomplicated vs complicated disease. Patients with visually intact appendix were excluded. Complicated appendicitis was diagnosed intraoperatively by surgeon as the presence of at least one of five signs: destructive appendicitis, visible perforation, intraabdominal fecalith, abscess, or peritonitis. NLR was calculated and compared with intraoperative findings. Descriptive and analytical statistics was carried out by SPSS23 (IBM); p<0.05 was considered significant. Based on intraoperative findings, appendix was intact in 14 cases (5.8%). Among remaining patients, non-complicated appendicitis was present in 151 cases (62.4%) and complicated appendicitis in 91 cases (37.6%). NLR higher than 8.8 was statistically significant in discriminating non-complicated vs complicated appendicitis (p=0.0002). In the whole group, mean NLR was 9.24 [95% confidence interval CI: 8.12–10.35]. Non-complicated appendicitis was associated with mean NLR of 7.98 [6.81–9.15]. Patients showing a single sign of complicated appendicitis had mean NLR of 9.37 [7.76–11.03], two signs – 11.45 [9.04–13.95], three or more – 13.65 [8.25–19.05]. However there were no statistically significant differences (p=0.092) within the complicated group. In contrast there were significant differences in NLR distribution between non-complicated and complicated appendicitis (p<0.05). NLR is statistically significant marker to differentiate between non-complicated and complicated appendicitis. Our study supports the previously reported diagnostic threshold of 8.8. Higher NLR could predict more complex intraoperative findings and thus help to choose appropriate surgical approach.