title: Risk factors for infections due to carbapenem-resistant Klebsiella pneumoniae after open heart surgery.
abstract: Patients undergoing major surgery are at increased risk of developing infections due to resistant organisms, including carbapenem-resistant Klebsiella pneumoniae (CR-Kp). In this study, we assessed risk factors for CR-Kp infections after open heart surgery in a teaching hospital in northern Italy.
  
  
  
  A retrospective study was conducted from January to December 2014. The primary outcome measure was postoperative CR-Kp infection, defined as a time-to-event end-point. The effect of potentially related variables was assessed by univariable and multivariable analyses. Secondary end-points were in-hospital mortality and 180-day postoperative mortality.
  
  
  
  Among 553 patients undergoing open heart surgery, 32 developed CR-Kp infections (6%). In the final multivariable model, CR-Kp colonization [hazard ratio (HR) 227.45, 95% confidence intervals (CI) 67.13-1225.20, P < 0.001], cardiopulmonary bypass time in minutes (HR 1.01, 95% CI 1.01-1.02, P < 0.001), chronic obstructive pulmonary disease (HR 3.99, 95% CI 1.61-9.45, P = 0.004), SOFA score (HR 1.29, 95% CI 1.08-1.53, P = 0.007), preoperative mechanical ventilation (HR 8.10, 95% CI 1.31-48.57, P = 0.026), prolonged mechanical ventilation (HR 2.48, 95% CI 1.08-6.15, P = 0.032) and female sex (HR 2.08, 95% CI 1.00-4.36, P = 0.049) were associated with the development of CR-Kp infection. Increased in-hospital mortality and 180-day mortality were observed in patients who developed CR-Kp infections in comparison with those who did not.
  
  
  
  In our cohort, CR-Kp colonization was an important predictor of CR-Kp infection after open heart surgery. CR-Kp infection after surgery significantly affected survival. Preventing colonization is conceivably the most effective current strategy to reduce the impact of CR-Kp.
authors.affiliation: Division of Cardiac Surgery, IRCCS San Martino-IST, Genoa, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Salsano
authors.affiliation: Infectious Diseases Division, University of Genoa (DISSAL) and IRCCS San Martino-IST, Genoa, Italy daniele.roberto.giacobbe@gmail.com.
authors.forename: Daniele Roberto
authors.initials: DR
authors.lastname: Giacobbe
authors.affiliation: Division of Cardiac Surgery, IRCCS San Martino-IST, Genoa, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Sportelli
authors.affiliation: Division of Cardiac Surgery, IRCCS San Martino-IST, Genoa, Italy.
authors.forename: Guido Maria
authors.initials: GM
authors.lastname: Olivieri
authors.affiliation: Division of Cardiac Surgery, IRCCS San Martino-IST, Genoa, Italy.
authors.forename: Carlotta
authors.initials: C
authors.lastname: Brega
authors.affiliation: Division of Cardiac Surgery, IRCCS San Martino-IST, Genoa, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Di Biase
authors.affiliation: Microbiology Unit, University of Genoa (DISC) and IRCCS San Martino-IST, Genoa, Italy.
authors.forename: Erika
authors.initials: E
authors.lastname: Coppo
authors.affiliation: Microbiology Unit, University of Genoa (DISC) and IRCCS San Martino-IST, Genoa, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Marchese
authors.affiliation: Infectious Diseases Division, University of Genoa (DISSAL) and IRCCS San Martino-IST, Genoa, Italy.
authors.forename: Valerio
authors.initials: V
authors.lastname: Del Bono
authors.affiliation: Infectious Diseases Division, University of Genoa (DISSAL) and IRCCS San Martino-IST, Genoa, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Viscoli
authors.affiliation: Division of Cardiac Surgery, IRCCS San Martino-IST, Genoa, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Santini
mesh_terms: D000368:Aged; D015780:Carbapenems / Q000494:pharmacology*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D005260:Female; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D007558:Italy / Q000453:epidemiology; D007710:Klebsiella Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000302:isolation & purification*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D015996:Survival Rate / Q000639:trends; D018440:beta-Lactam Resistance
chemical_list: D015780:Carbapenems
keywords: Carbapenemases; Cardiac surgery; KPC; Klebsiella; Postoperative infections