title: Comparison of neutrophil:lymphocyte ratios following coronary artery bypass surgery with or without cardiopulmonary bypass.
abstract: OBJECTIVE
  Coronary artery bypass graft (CABG) surgery may induce postoperative systemic changes in leukocyte counts, including leukocytosis, neutrophilia or lymphopenia. This retrospective clinical study investigated whether off-pump coronary artery bypass (OPCAB) surgery working on the beating heart without extracorporeal circulation could favourably affect leukocyte counts, including neutrophil-tolymphocyte (N:L) ratio, after CABG.
  
  
  METHODS
  In this study, 30 patients who underwent isolated CABG with cardiopulmonary bypass (CPB), and another 30 patients who underwent the same operation without CPB between May 2010 and May 2013, were screened from the computerised database of our hospital. Pre-operative, and first and fifth postoperative day differential counts of leukocytes with the N:L ratio of peripheral blood were obtained.
  
  
  RESULTS
  A significant increase in total leukocyte and neutrophil counts and N:L ratio, and a decrease in lymphocyte counts were observed at all time points after surgery in both groups. N:L ratio was significantly higher in the CPB group compared with the OPCAB group on the first postoperative day (20.73 ± 13.85 vs 10.19 ± 4.55, p < 0.001), but this difference disappeared on the fifth postoperative day.
  
  
  CONCLUSIONS
  CPB results in transient but significant changes in leukocyte counts in the peripheral blood stream in terms of N:L ratio compared with the off-pump technique of CABG.
authors.affiliation: Department of Cardiovascular Surgery, Faculty of Medicine, Afyon Kocatepe University, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Aldemir
authors.affiliation: Department of Anaesthesiology, Faculty of Medicine, Afyon Kocatepe University, Turkey.
authors.forename: Elif Doğan
authors.initials: ED
authors.lastname: Baki
authors.affiliation: Department of Cardiovascular Surgery, Faculty of Medicine, Afyon Kocatepe University, Turkey.
authors.forename: Fahri
authors.initials: F
authors.lastname: Adali
authors.affiliation: Department of Cardiovascular Surgery, Faculty of Medicine, Afyon Kocatepe University, Turkey.
authors.forename: Görkem
authors.initials: G
authors.lastname: Çarşanba
authors.affiliation: Department of Cardiovascular Surgery, Faculty of Medicine, Afyon Kocatepe University, Turkey.
authors.forename: Evren
authors.initials: E
authors.lastname: Tecer
authors.affiliation: Department of Public Health, Faculty of Medicine, Afyon Kocatepe University, Turkey.
authors.forename: Hanife Uzel
authors.initials: HU
authors.lastname: Taş
mesh_terms: D000368:Aged; D002315:Cardiopulmonary Bypass / Q000379:methods*; D001026:Coronary Artery Bypass / Q000379:methods; D047549:Coronary Artery Bypass, Off-Pump / Q000379:methods*; D003324:Coronary Artery Disease / Q000601:surgery*; D005260:Female; D006801:Humans; D007902:Length of Stay; D007958:Leukocyte Count; D007964:Leukocytosis / Q000453:epidemiology*; D018655:Lymphocyte Count; D008231:Lymphopenia / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000166:cytology*; D011183:Postoperative Complications / Q000453:epidemiology*; D012189:Retrospective Studies