Discrimination of infectious and noninfectious causes of early acute respiratory distress syndrome by procalcitonin

Crit Care Med. 1999 Oct;27(10):2172-6. doi: 10.1097/00003246-199910000-00016.


Objective: To test the sepsis marker procalcitonin (PCT) for its applicability to discriminate between septic and nonseptic causes of acute respiratory distress syndrome (ARDS).

Design: Prospective study, assessing the course of PCT serum levels in early (within 72 hrs after onset) ARDS. The three other inflammation markers neopterin, interleukin-6 (IL-6), and C-reactive protein (CRP) were tested in parallel.

Setting: Twenty-four-bed medical intensive care unit of a 1,990-bed primary hospital, providing health care for an estimated 39,000 patients.

Patients: Twenty-seven patients, 18 male and nine female, aged 16-85 yrs, with early ARDS of known cause (17 with septic and ten with nonseptic ARDS) were enrolled in a prospective study between May 1994 and May 1995.

Interventions: Serum samples were drawn every 4-6 hrs for measurement of PCT, neopterin, IL-6, and CRP concentrations. Blood cultures, tracheal aspirates, and urine samples were obtained every 12-24 hrs. In 24 of 27 patients, bronchoscopic cultures were also obtained. Clinical sepsis criteria as defined by the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference were checked daily.

Measurements and main results: Assessment of inflammation marker serum levels in septic vs. nonseptic ARDS. PCT serum levels were significantly higher (p < .0005) in the patients with septic ARDS than in patients with nonseptic ARDS within 72 hrs after onset of ARDS. There was no overlap between the two groups. Also, neopterin allowed a differentiation (p < .005), although a substantial overlap between serum levels of septic and nonseptic patients was observed. No discrimination could be achieved by determination of CRP and IL-6 levels.

Conclusion: PCT determination in early ARDS could help to discriminate between septic and nonseptic underlying disease.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Bacteria / isolation & purification
  • Bacterial Infections / blood
  • Bacterial Infections / complications
  • Bacterial Infections / microbiology
  • Biomarkers / blood
  • Biopsy
  • Bronchoscopy
  • C-Reactive Protein / metabolism
  • Calcitonin / blood*
  • Calcitonin Gene-Related Peptide
  • Female
  • Glycoproteins / blood*
  • Humans
  • Intensive Care Units
  • Interleukin-6 / blood
  • Male
  • Middle Aged
  • Neopterin / blood
  • Prospective Studies
  • Protein Precursors / blood*
  • Respiratory Distress Syndrome / blood*
  • Respiratory Distress Syndrome / etiology
  • Respiratory Distress Syndrome / pathology
  • Sepsis / blood
  • Sepsis / complications*
  • Sepsis / microbiology


  • Biomarkers
  • CALCA protein, human
  • Glycoproteins
  • Interleukin-6
  • Protein Precursors
  • Neopterin
  • Calcitonin
  • C-Reactive Protein
  • Calcitonin Gene-Related Peptide