title: Activated partial thromboplastin time waveform analysis: a new tool to detect infection?
abstract: OBJECTIVE
  An abnormality of the optical transmission waveform obtained during measurement of the activated partial thromboplastin time (aPTT) has been described to identify a high-risk intensive care unit population consisting of patients with sepsis or with higher mortality rates than patients with normal aPTT waveforms. We investigated the abnormal aPTT biphasic waveform as a diagnostic and prognostic marker of infection.
  
  
  METHODS
  Prospective, observational study investigating the predictive value of aPTT waveform analysis for the diagnosis and prognosis of sepsis.
  
  
  METHODS
  Surgical intensive care unit of a university hospital.
  
  
  METHODS
  We studied 187 consecutive patients who fulfilled at least two or more criteria of the systemic inflammatory response syndrome at admission or during intensive care stay and classified as having systemic inflammatory response syndrome, sepsis, severe sepsis, or septic shock during an 8-month period.
  
  
  METHODS
  Laboratory analyses including aPTT waveform analysis and procalcitonin and C-reactive protein concentrations were measured at days 1-3.
  
  
  RESULTS
  The final diagnoses were systemic inflammatory response syndrome in 49%, sepsis in 16%, severe sepsis in 12%, and septic shock in 23% of patients. On day 1, the biphasic waveform was significantly more abnormal in patients with severe sepsis or septic shock than in patients with systemic inflammatory response syndrome or sepsis. The biphasic waveform was more accurate than procalcitonin and C-reactive protein for differentiating patients with severe sepsis and septic shock, with 90% sensitivity and 92% negative predictive value. Biphasic waveform values were significantly more abnormal during days 1-3 in septic nonsurvivors than in survivors and nonseptic nonsurvivors. The biphasic waveform exhibited the best specificity (91%) and negative predictive value (98%) for the prognosis of sepsis-related mortality on day 3.
  
  
  CONCLUSIONS
  In intensive care units, when the analyzer is available, aPTT waveform analysis is an inexpensive, rapid, effective, and readily available tool providing information for the diagnosis of severe sepsis and the prognosis of septic patients.
authors.affiliation: Service de Réanimation Chirurgicale and Laboratoire d'Hémostase, Hospices Civils de Lyon, Hôpital Edouard Herriot, Lyon, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Chopin
authors.forename: Bernard
authors.initials: B
authors.lastname: Floccard
authors.forename: Frédéric
authors.initials: F
authors.lastname: Sobas
authors.forename: Julien
authors.initials: J
authors.lastname: Illinger
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Boselli
authors.forename: Farida
authors.initials: F
authors.lastname: Benatir
authors.forename: Albrice
authors.initials: A
authors.lastname: Levrat
authors.forename: Christian
authors.initials: C
authors.lastname: Guillaume
authors.forename: Jullien
authors.initials: J
authors.lastname: Crozon
authors.forename: Claude
authors.initials: C
authors.lastname: Négrier
authors.forename: Bernard
authors.initials: B
authors.lastname: Allaouchiche
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D002116:Calcitonin / Q000097:blood; D015740:Calcitonin Gene-Related Peptide; D005260:Female; D005500:Follow-Up Studies; D006023:Glycoproteins / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D010314:Partial Thromboplastin Time; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood; D018805:Sepsis / Q000097:blood / Q000175:diagnosis* / Q000401:mortality; D012720:Severity of Illness Index; D015996:Survival Rate
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D006023:Glycoproteins; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide