Limited value of preoperative neutrophil-to-lymphocyte ratio to predict post-operative outcomes after major emergency abdominal surgery.

INTRODUCTION Major emergency abdominal surgery results in a high risk of morbidity and mortality. Preoperative neutrophil-to-lymphocyte ratio (NLR) has been proposed as a predictor of post-operative outcomes in elective surgery. The aim of the present study was to examine whether preoperative NLR was associated with post-operative morbidity and mortality after major emergency abdominal surgery. METHODS We conducted a retrospective cohort study of patients undergoing major emergency abdominal surgery in two university hospitals in Denmark between 2010 and 2016. Associations between preoperative NLR and 30-day post-operative complications and mortality were established through multivariate logistic regression and receiver-operating characteristics (ROC) analysis. RESULTS A total of 570 patients were included in the study. The overall 30-day mortality was 9.3% and 59.3% had post-operative complications. The median preoperative NLR was 8.6 (interquartile range: 4.8-14.7). Although NLR was higher in the group of patients who had complications or died after surgery, a multivariate analysis showed that the NLR was not associated with 30-day post-operative complications (odds ratio (OR) = 1.01 (95% confidence interval (CI): 0.99-1.02); p = 0.424) or mortality (OR = 0.99 (95% CI: 0.97-1.02); p = 0.57). The ROC analysis showed an area under the curve of 0.55 and 0.60 for 30-day post-operative complications and mortality, respectively. CONCLUSIONS Preoperative NLR was not associated with 30-day post-operative complications and mortality in patients undergoing major emergency abdominal surgery. FUNDING none. TRIAL REGISTRATION not relevant.

Peri-operative endothelial dysfunction in patients undergoing minor abdominal surgery: An observational study.

BACKGROUND: Myocardial injury after noncardiac surgery is common and associated with major adverse cardiac events. Surgery induces acute endothelial dysfunction, which might be central in the pathophysiology of myocardial injury; however, the relationship between surgical stress and endothelial function remains incompletely understood. OBJECTIVES: This study aimed to assess the acute peri-operative changes in endothelial function after minor elective abdominal surgery. DESIGN: A prospective, observational, single-centre study. SETTING: A university hospital from February 2016 to January 2017. PATIENTS: Sixty patients undergoing elective minor abdominal surgery. MAIN OUTCOME MEASURES: The change in endothelial function, expressed as the reactive hyperaemia index (RHI), was assessed by non-invasive digital pulse tonometry. RHI, biomarkers of nitric oxide bioavailability and oxidative stress were assessed prior to and 4 h after surgery. RESULTS: RHI decreased significantly from 1.93 [95% confidence interval (95% CI 1.78 to 2.09)] before surgery to 1.76 (95% CI 1.64 to 1.90), P = 0.03, after surgery. The nitric oxide production, L-arginine/asymmetric dimethylarginine, decreased significantly from a ratio of 213.39 (95% CI 188.76 to 241.2) to a ratio of 193.3 (95% CI 171.82 to 217.54), P = 0.03. Plasma biopterins increased significantly after surgery, while the ratio between tetrahydrobiopterin and dihydrobiopterin was unchanged. Total ascorbic acid decreased significantly after surgery (P < 0.001), while its oxidation ratio was unchanged. CONCLUSION: Elective minor abdominal surgery impaired systemic endothelial function early after surgery. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02690233.