title: Incidence and risk factors for pulmonary exacerbation treatment failures in patients with cystic fibrosis chronically infected with Pseudomonas aeruginosa.
abstract: BACKGROUND
  Pulmonary exacerbations (PEx) are responsible for much of the morbidity and mortality associated with cystic fibrosis (CF). However, there is a paucity of data on outcomes in CF PEx and factors influencing outcomes.
  
  
  METHODS
  We reviewed all PEx in patients infected with Pseudomonas aeruginosa treated with parenteral antibiotics over 4 years at our center. Treatment failures were categorized a priori as those PEx requiring antibiotic regimen change, prolongation of therapy > 20 days because of failure to respond, an early recurrent event within < 45 days, or failure to recover lung function to > 90% of baseline FEV(1).
  
  
  RESULTS
  A total of 101 patients were followed for 452 PEx. Treatment failures were observed in 125 (28%) of PEx; antibiotic regimen change was observed in 27 (6%), prolongation of therapy in 29 (6%), early recurrent events in 63 (14%), and failure to recover lung function to > 90% of baseline FEV(1) in 66 (15%). Demographic factors associated with one or more treatment failures per year included advanced airways disease, use of enteric feeds, CF-related diabetes, and CF liver disease but did not include female sex or F508del homozygosity. Increased treatment failure risk was associated with lower admission FEV(1) and increased markers of inflammation. At therapeutic completion, increased inflammatory markers correlated with treatment failure. Failure rates decreased with increasing number of active antimicrobial agents used based on in vitro susceptibility (zero, 28/65 [43%]; one, 38/140 [27%]; two, 59/245 [24%]; three, 0/2 [0%]; P = .02).
  
  
  CONCLUSIONS
  One-fourth of PEx fail to respond adequately to initial management. Patient demographic and episode-specific clinical information can be used to identify individuals at increased risk of initial management failure.
authors.affiliation: Departments of Medicine, and Microbiology and Infectious Disease, University of Calgary, Calgary, AB, Canada; Northern Ireland Regional Adult Cystic Fibrosis Centre, Belfast City Hospital, Belfast, Ireland. Electronic address: mdparkin@ucalgary.ca.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Parkins
authors.affiliation: Northern Ireland Regional Adult Cystic Fibrosis Centre, Belfast City Hospital, Belfast, Ireland.
authors.forename: Jacqueline C
authors.initials: JC
authors.lastname: Rendall
authors.affiliation: Northern Ireland Regional Adult Cystic Fibrosis Centre, Belfast City Hospital, Belfast, Ireland; Centre for Infection and Immunity, Queen's University of Belfast, Belfast, Ireland.
authors.forename: J Stuart
authors.initials: JS
authors.lastname: Elborn
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D003550:Cystic Fibrosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D015994:Incidence; D007263:Infusions, Parenteral; D016015:Logistic Models; D008297:Male; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000503:physiopathology*; D012129:Respiratory Function Tests; D012307:Risk Factors; D017211:Treatment Failure
chemical_list: D000900:Anti-Bacterial Agents