title: Usefulness of C-reactive protein in monitoring the severe community-acquired pneumonia clinical course.
abstract: BACKGROUND
  The aim of the present study was to evaluate the C-reactive protein level, the body temperature and the white cell count in patients after prescription of antibiotics in order to describe the clinical resolution of severe community-acquired pneumonia.
  
  
  METHODS
  A cohort of 53 consecutive patients with severe community-acquired pneumonia was studied. The C-reactive protein levels, body temperature and white cell count were monitored daily.
  
  
  RESULTS
  By day 3 a C-reactive protein level 0.5 times the initial level was a marker of poor outcome (sensitivity, 0.91; specificity, 0.59). Patients were divided according to their C-reactive protein patterns of response to antibiotics, into fast response, slow response, nonresponse, and biphasic response. About 96% of patients with a C-reactive protein pattern of fast response and 74% of patients with a slow response pattern survived, whereas those patients with the patterns of nonresponse and of biphasic response had a mortality rate of 100% and 33%, respectively (P < 0.001). On day 3 of antibiotic therapy, a decrease in C-reactive protein levels by 0.31 or more from the previous day's level was a marker of good prognosis (sensitivity, 0.75; specificity, 0.85).
  
  
  CONCLUSIONS
  Daily C-reactive protein measurement after antibiotic prescription is useful in identification, as early as day 3, of severe community-acquired pneumonia patients with poor outcome. The identification of the C-reactive protein pattern of response to antibiotic therapy was useful in the recognition of the individual clinical course, either improving or worsening, as well as the rate of improvement, in patients with severe community-acquired pneumonia.
authors.affiliation: Unidade de Cuidados Intensivos, Hospital Garcia de Orta, Almada, Portugal. luismiguelcoelho16@gmail.com
authors.forename: Luís
authors.initials: L
authors.lastname: Coelho
authors.forename: Pedro
authors.initials: P
authors.lastname: Póvoa
authors.forename: Eduardo
authors.initials: E
authors.lastname: Almeida
authors.forename: Antero
authors.initials: A
authors.lastname: Fernandes
authors.forename: Rui
authors.initials: R
authors.lastname: Mealha
authors.forename: Pedro
authors.initials: P
authors.lastname: Moreira
authors.forename: Henrique
authors.initials: H
authors.lastname: Sabino
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D001831:Body Temperature; D002097:C-Reactive Protein / Q000378:metabolism*; D015331:Cohort Studies; D017714:Community-Acquired Infections / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology; D018450:Disease Progression; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000097:blood* / Q000188:drug therapy* / Q000503:physiopathology; D011237:Predictive Value of Tests; D011446:Prospective Studies
chemical_list: D000900:Anti-Bacterial Agents; D015415:Biomarkers; D002097:C-Reactive Protein