title: Can clear ascitic fluid appearance rule out spontaneous bacterial peritonitis?
abstract: OBJECTIVE
  The objective of the study was to determine the sensitivity and specificity of abnormal ascitic fluid appearance in the detection of spontaneous bacterial peritonitis (SBP), as a sensitivity approaching 100% could exclude SBP if the fluid is clear.
  
  
  METHODS
  We performed a retrospective review of all ascitic fluid samples sent for cell count over a 4-year period. Spontaneous bacterial peritonitis was defined as an absolute neutrophil count of more than 250 cells/mm3 or a positive culture. Abnormal fluid appearance was defined as hazy, cloudy, or bloody.
  
  
  RESULTS
  There were 916 ascitic fluid samples analyzed during the study period. Eighteen percent of samples had a clear appearance, whereas 82% were abnormal. Abnormal ascitic fluid appearance had a sensitivity of 98.1% (95% confidence interval, 95.3%-99.5%) and a specificity of 22.7% (95% confidence interval, 19.4%-26.3%) in the detection of SBP.
  
  
  CONCLUSIONS
  Abnormal fluid appearance has a high sensitivity for the detection of SBP. Thus, clear fluid might safely exclude SBP.
authors.affiliation: Department of Emergency Medicine, UCSF-Fresno Medical Education Program, Community Regional Medical Center, Fresno, CA 93701, USA. b.chinnock@comcast.net
authors.forename: Brian
authors.initials: B
authors.lastname: Chinnock
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Hendey
mesh_terms: D001202:Ascitic Fluid / Q000166:cytology*; D001424:Bacterial Infections / Q000175:diagnosis*; D006801:Humans; D007958:Leukocyte Count; D009504:Neutrophils; D019152:Paracentesis; D010538:Peritonitis / Q000175:diagnosis* / Q000382:microbiology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity