title: An observational study to know the association of leukocytosis and fever with infection in post cardiac surgery patients.
abstract: BACKGROUND
  Leukocytosis and fever in the absence of infection are common phenomena in post surgical period. The systemic inflammatory response syndrome induced by surgical trauma is a well-known entity, with resultant release of variety of inflammatory cytokines leading to fever and/or leukocytosis in spite of the absence of infection.
  
  
  OBJECTIVE
  To know the association of leukocytosis and fever with infection in immediate post cardiac surgical period.
  
  
  METHODS
  It was a retrospective, observational study including 569 patients, who underwent cardiac surgeries in our institute. All demographic data, comorbidities and other factors associated with fever and/or leukocytosis were analyzed. The sensitivity and specificity of fever and/or leukocytosis were analyzed for the diagnosis of infection.
  
  
  RESULTS
  Out of 569 patients; 49 patients (9%) had evidence of infection on microbiological culture. Mean total leukocyte counts (TLC) on zero and 1st postoperative days were associated with infection with a sensitivity (75.5% and 63.3%) and specificity (15.8% and 24.0%) respectively. Mean maximum temperature (Tmax) on zero and 1st postoperative days were associated with infection with a sensitivity (20.4% and 24.5%) and specificity of (82.5% and 83.3%) respectively. The combined sensitivity and specificity of leukocytosis and fever for the diagnosis of infection on 2nd postoperative day was 14.3% and 91.5% respectively.
  
  
  CONCLUSIONS
  Fever and leukocytosis are poor predictors of diagnosing infection on the first two postoperative days. However, fever and leukocytosis combined together have low sensitivity (14.3%) with high specificity (91.5%) for the diagnosis of infection on the 2nd and subsequent postoperative days.
authors.affiliation: Department of Anesthesiology, Critical Care and Cardiovascular Surgery, Escorts Heart Institute and Research Centre, New Delhi, India.
authors.forename: Satish
authors.initials: S
authors.lastname: Kumar
authors.forename: Yatin
authors.initials: Y
authors.lastname: Mehta
authors.forename: Mayank
authors.initials: M
authors.lastname: Vats
authors.forename: Rajesh
authors.initials: R
authors.lastname: Chand
authors.forename: Pawan
authors.initials: P
authors.lastname: Kapoor
authors.forename: Naresh
authors.initials: N
authors.lastname: Trehan
mesh_terms: D006348:Cardiac Surgical Procedures; D005260:Female; D005334:Fever / Q000175:diagnosis*; D006801:Humans; D007239:Infections / Q000175:diagnosis*; D007964:Leukocytosis / Q000175:diagnosis*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity