Changes in neutrophil activity following cardiovascular surgery

Abstract

Jarrod P Meadows1,2, James A Tumlin3, Mark G Clemens4, Iain H McKillop1,4, Susan Evans1,21Department of Surgery; 2FH “Sammy” Ross Jr Trauma Center, Carolinas Medical Center, Charlotte, NC, USA; 3Department of Medicine, Division of Nephrology, University of Tennessee College of Medicine at Chattanooga, Chattanooga, TN, USA; 4Department of Biology, University of North Carolina at Charlotte, Charlotte, NC, USABackground: Neutrophils are implicated in initiating perioperative inflammation and postoperative outcome, particularly in patients with acute renal failure. The aim of the current study was to assess the role of neutrophil function in patients following cardiovascular surgery with mild preoperative renal dysfunction (PRD).Materials and methods: Patients scheduled for cardiovascular operations were screened for renal function, and divided into those with glomerular filtration rate (GFR) < 60 mL/minute (PRD, n = 9), and GFR > 60 mL/minute (normal controls; [C] n = 7). Neutrophils were isolated from plasma preoperatively, and 2, 24, and 48 hours postoperatively. Neutrophil activity (respiratory burst; RB) and apoptosis were then determined.Results: In the whole population, neutrophil apoptosis decreased from 67% preoperatively, to 42% postoperatively, with no significant difference between the groups (C = 64.8%–41.2%, PRD = 68.2%–42.6%). RB increased by 70% postoperatively in the whole population, with no significant difference between the groups (C = 68.1%, PRD = 72.9%, P = 0.86).Conclusion: Collectively these data demonstrate that, in addition to decreasing neutrophil apoptosis, cardiovascular surgery leads to increased neutrophil RB, thus contributing to postoperative systemic oxidative stress. This can lead to clinically significant complications and tissue damage. Our data also suggest that differences in postoperative inflammation between patients with and without PRD, do not exist, at least in the setting of mild preoperative renal insufficiency.Keywords: neutrophil, renal function, apoptosis, respiratory burst, glomerular filtration rate