title: First episodes of peritoneal infection: description and prognostic factors.
abstract: BACKGROUND
  Peritonitis is one of the most common and severe complications associated with peritoneal dialysis (PD), constituting the primary cause of catheter loss and exit from the dialysis technique. The incidence and aetiology of peritonitis episodes vary based on geographical region, and change over time. For this reason, it is vital to maintain an updated understanding of the current risk factors and prognostic factors associated with peritonitis.
  
  
  METHODS
  We performed an observational, multi-centre, prospective cohort study with a maximum follow-up period of 7 years (2003-2010), which included 1177 patients and a total of 476 first episodes of peritonitis (total: 1091 cases of peritonitis).
  
  
  RESULTS
  We describe the characteristics of the first episode of peritonitis from a large and current study sample. The factors associated with a shorter interval until the first episode of peritonitis as selected by the multivariate analysis included prior cardiovascular comorbidity (Hazard Ratio [HR]: 1.25 [1.04-1.58]), having previously received haemodialysis (HR: 1.39 [1.10-1.76]) or a kidney transplant (HR: 1.38 [1.10-1.93]), having started PD on a manual modality (HR: 1.39 [1.13-1.73]), and initial age >70 years (HR: 1.53 [1.23-1.90]). The first episode of peritonitis was associated with a 7.8% rate of recurrence, an 11.7% rate of catheter removal, and a mortality rate within one month of the episode of 1.3%. The progression of peritonitis infections depended on the type of causal microorganism. We calculated a greater risk for gram-negative bacterial infections (Odds Ratio [OR]: 5.31 [2.26-12.48]) and the aggregate group of infections caused by multiple microorganisms, fungal infections, and mycobacterial infections (OR: 38.24 [13.84-105.63]), as compared to gram-positive bacterial infections.
  
  
  CONCLUSIONS
  The development of a first case of peritonitis depends on the characteristics of the patient upon starting dialysis, comorbidities present, and the technique used. Patients at a greater risk for peritonitis must receive special care during training and follow-up.
authors.affiliation: Servicio de Nefrología, Hospital Universitario Puerta de Hierro, Majadahonda, Madrid, (REDINREN) ISC III 06/0016 y 12/0021, Spain. josem.portoles@salud.madrid.org
authors.forename: José
authors.initials: J
authors.lastname: Portolés
authors.forename: Darío
authors.initials: D
authors.lastname: Janeiro
authors.forename: Luis M
authors.initials: LM
authors.lastname: Lou-Arnal
authors.forename: Paula
authors.initials: P
authors.lastname: López-Sánchez
authors.forename: Mayra
authors.initials: M
authors.lastname: Ortega
authors.forename: Gloria
authors.initials: G
authors.lastname: del Peso
authors.forename: Carmen
authors.initials: C
authors.lastname: Felipe
authors.forename: Ana M
authors.initials: AM
authors.lastname: Tato
authors.forename: Mercedes
authors.initials: M
authors.lastname: Velo
authors.forename: Inés
authors.initials: I
authors.lastname: Castellano
authors.forename: Vicente
authors.initials: V
authors.lastname: Pérez-Díaz
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010538:Peritonitis / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology*; D011379:Prognosis; D011446:Prospective Studies; D006435:Renal Dialysis; D012307:Risk Factors; D015996:Survival Rate