title: Severe acute kidney injury following cardiac surgery: short-term outcomes in patients undergoing continuous renal replacement therapy (CRRT).
abstract: BACKGROUND
  Acute kidney injury (AKI) represents a major complication of cardiac surgery. Our aim was to evaluate, in patients undergoing continuous renal replacement therapy (CRRT) for cardiac surgery-associated AKI (CS-AKI), prognostic factors related to in-hospital survival and renal function recovery to independence from RRT.
  
  
  METHODS
  We conducted a retrospective analysis in patients with severe CS-AKI who underwent CRRT for at least 48 h. The sequential organ failure assessment (SOFA) score was calculated on a daily basis to evaluate illness severity throughout the intensive care unit (ICU) stay.
  
  
  RESULTS
  In 264 patients (age 66.4 ± 11.7 years, 192 males), 30-day survival was 57.6 % while survival to discharge from the hospital was 40.5 %. Renal function recovery occurred in 96.3 % of survivors and in 13.4 % of non-survivors (p < 0.001). Multivariate analysis selected advancing age, oliguria, sepsis and the highest level of SOFA score within the first week of CRRT (SOFA-max) as independent prognostic factors for failure to recover renal function. Female gender was associated with a higher probability of survival, while higher serum creatinine at the start of CRRT, oliguria, sepsis and SOFA-max were independently associated with mortality. The subgroup of patients with a day-1 SOFA score above the median (≥10) showed a lower probability of survival and a lower cumulative incidence of renal function recovery.
  
  
  CONCLUSIONS
  In a selected population of patients with severe CS-AKI requiring RRT, short-term outcomes appear strongly associated with the worst grade of illness severity during the first week of CRRT, thus reflecting the sequential occurrence of additional major complications during ICU stay. Renal function recovery and in-hospital survival appear mutually linked, sharing oliguria, sepsis and SOFA score as the main determinants of both outcomes.
authors.affiliation: Hemodialysis Unit, Department of Nephrology and Urology, Umberto I, Policlinico di Roma, "Sapienza" University, Viale del Policlinico, 155, 00161, Rome, Italy. valentina.pistolesi@uniroma1.it.
authors.forename: Valentina
authors.initials: V
authors.lastname: Pistolesi
authors.affiliation: Dialysis and Renal Transplant Italian Registry, Technical Committee, Rome, Italy.
authors.forename: Anteo
authors.initials: A
authors.lastname: Di Napoli
authors.affiliation: Acute and Chronic Renal Failure Unit, Department of Clinical and Experimental Medicine, Parma University, Parma, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Fiaccadori
authors.affiliation: Hemodialysis Unit, Department of Nephrology and Urology, Umberto I, Policlinico di Roma, "Sapienza" University, Viale del Policlinico, 155, 00161, Rome, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Zeppilli
authors.affiliation: Hemodialysis Unit, Department of Nephrology and Urology, Umberto I, Policlinico di Roma, "Sapienza" University, Viale del Policlinico, 155, 00161, Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Polistena
authors.affiliation: Hemodialysis Unit, Department of Nephrology and Urology, Umberto I, Policlinico di Roma, "Sapienza" University, Viale del Policlinico, 155, 00161, Rome, Italy.
authors.forename: Maria Itala
authors.initials: MI
authors.lastname: Sacco
authors.affiliation: Acute and Chronic Renal Failure Unit, Department of Clinical and Experimental Medicine, Parma University, Parma, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Regolisti
authors.affiliation: Department of Anesthesiology and Intensive Care, Cardiac Surgery ICU, Umberto I, Policlinico di Roma, "Sapienza" University, Rome, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Tritapepe
authors.affiliation: Hemodialysis Unit, Department of Nephrology and Urology, Umberto I, Policlinico di Roma, "Sapienza" University, Viale del Policlinico, 155, 00161, Rome, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pierucci
authors.affiliation: Hemodialysis Unit, Department of Nephrology and Urology, Umberto I, Policlinico di Roma, "Sapienza" University, Viale del Policlinico, 155, 00161, Rome, Italy.
authors.forename: Santo
authors.initials: S
authors.lastname: Morabito
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis / Q000209:etiology / Q000401:mortality / Q000628:therapy*; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000009:adverse effects* / Q000401:mortality; D016009:Chi-Square Distribution; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009846:Oliguria / Q000209:etiology; D063305:Organ Dysfunction Scores; D010351:Patient Discharge; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D020127:Recovery of Function; D017582:Renal Replacement Therapy / Q000009:adverse effects / Q000401:mortality; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D018805:Sepsis / Q000209:etiology; D012720:Severity of Illness Index; D012737:Sex Factors; D013997:Time Factors; D016896:Treatment Outcome
keywords: Acute kidney injury; CRRT; CVVH; CVVHDF; Cardiac surgery; Renal function recovery