title: Assessing fluid responsiveness in critically ill patients: False-positive pulse pressure variation is detected by Doppler echocardiographic evaluation of the right ventricle.
abstract: OBJECTIVE
  To determine whether peak systolic velocity of tricuspid annular motion assessed by tissue Doppler echocardiography (Sta), a right ventricular function parameter, can discriminate patients with true- and false-positive pulse pressure variation. Pulse pressure variation is used to predict fluid responsiveness in mechanically ventilated patients. However, this parameter has been reported to be falsely positive, especially in patients with right ventricular dysfunction.
  
  
  METHODS
  A prospective study.
  
  
  METHODS
  Medical and surgical intensive care unit of a university hospital.
  
  
  METHODS
  Thirty- five mechanically ventilated patients hospitalized for >24 hrs with a pulse pressure variation of >12%.
  
  
  METHODS
  Doppler echocardiography (including measurement of Sta and stroke volume) was performed before and after infusion of 500 mL of colloid solution. Patients were classified into two groups according to their response to fluid infusion: responders (at least 15% increase in stroke volume) and nonresponders.
  
  
  RESULTS
  Twenty-three patients (66%) were responders (true-positive group) and 12 (34%) were nonresponders (false-positive group). Before volume expansion, Sta was statistically lower in the nonresponder group (0.13 [0.04] vs. 0.20 [0.05], p = .0004). The area under the curve of the receiver operating characteristic curve was 0.87 (95% confidence interval, 0.74-1). In patients with pulse pressure variation of >12%, a Sta cutoff value of 0.15 m/s discriminated between responders and nonresponders with a sensitivity of 91% (80-100) and a specificity of 83% (62-100).
  
  
  CONCLUSIONS
  A Sta value of <0.15 m/s seems to be an accurate parameter to detect false-positive pulse pressure variation. Echocardiography should therefore be performed before fluid infusion in patients with pulse pressure variation of >12%.
authors.affiliation: Medical (YM, CP, AF, EL, FT, CG, HD) and Surgical Intensive Care Unit (EZ), Department of Anesthesia and Intensive Care, Amiens University Hospital, Amiens, France. mahjoub.yazine@chu-amiens.fr
authors.forename: Yazine
authors.initials: Y
authors.lastname: Mahjoub
authors.forename: Cyrille
authors.initials: C
authors.lastname: Pila
authors.forename: Arnaud
authors.initials: A
authors.lastname: Friggeri
authors.forename: Elie
authors.initials: E
authors.lastname: Zogheib
authors.forename: Eric
authors.initials: E
authors.lastname: Lobjoie
authors.forename: Francois
authors.initials: F
authors.lastname: Tinturier
authors.forename: Claude
authors.initials: C
authors.lastname: Galy
authors.forename: Michel
authors.initials: M
authors.lastname: Slama
authors.forename: Herve
authors.initials: H
authors.lastname: Dupont
mesh_terms: D000368:Aged; D016638:Critical Illness; D015150:Echocardiography, Doppler; D005189:False Positive Reactions; D005260:Female; D005440:Fluid Therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011674:Pulse; D013599:Systole; D016278:Ventricular Function, Right