title: Patient-ventilator asynchrony affects pulse pressure variation prediction of fluid responsiveness.
abstract: OBJECTIVE
  During partial ventilatory support, pulse pressure variation (PPV) fails to adequately predict fluid responsiveness. This prospective study aims to investigate whether patient-ventilator asynchrony affects PPV prediction of fluid responsiveness during pressure support ventilation (PSV).
  
  
  METHODS
  This is an observational physiological study evaluating the response to a 500-mL fluid challenge in 54 patients receiving PSV, 27 without (Synch) and 27 with asynchronies (Asynch), as assessed by visual inspection of ventilator waveforms by 2 skilled blinded physicians.
  
  
  RESULTS
  The area under the curve was 0.71 (confidence interval, 0.57-0.83) for the overall population, 0.86 (confidence interval, 0.68-0.96) in the Synch group, and 0.53 (confidence interval, 0.33-0.73) in the Asynch group (P = .018). Sensitivity and specificity of PPV were 78% and 89% in the Synch group and 36% and 46% in the Asynch group. Logistic regression showed that the PPV prediction was influenced by patient-ventilator asynchrony (odds ratio, 8.8 [2.0-38.0]; P < .003). Of the 27 patients without asynchronies, 12 had a tidal volume greater than or equal to 8 mL/kg; in this subgroup, the rate of correct classification was 100%.
  
  
  CONCLUSIONS
  Patient-ventilator asynchrony affects PPV performance during partial ventilatory support influencing its efficacy in predicting fluid responsiveness.
authors.affiliation: Anesthesia and Intensive Care Medicine, Maggiore della Carità University Hospital, Novara, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Messina
authors.affiliation: Anesthesia and Intensive Care Medicine, Maggiore della Carità University Hospital, Novara, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Colombo
authors.affiliation: Anesthesia and Intensive Care Medicine, Maggiore della Carità University Hospital, Novara, Italy.
authors.forename: Gianmaria
authors.initials: G
authors.lastname: Cammarota
authors.affiliation: Anesthesia and Intensive Care Medicine, Sant'Andrea Hospital (ASL VC), Vercelli, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: De Lucia
authors.affiliation: St George's Hospital, Intensive Care Medicine, London, United Kingdom.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Cecconi
authors.affiliation: Policlinico Universitario A. Gemelli, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Antonelli
authors.affiliation: Anesthesia and Intensive Care Medicine, Maggiore della Carità University Hospital, Novara, Italy; Department of Translational Medicine, Università del Piemonte Orientale "Amedeo Avogadro", Novara, Italy.
authors.forename: Francesco Della
authors.initials: FD
authors.lastname: Corte
authors.affiliation: Anesthesia and Intensive Care Medicine, Sant'Andrea Hospital (ASL VC), Vercelli, Italy; Department of Translational Medicine, Università del Piemonte Orientale "Amedeo Avogadro", Novara, Italy; CRRF Mons. L. Novarese, Moncrivello VC, Italy. Electronic address: paolo.navalesi@med.unipmn.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Navalesi
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012120:Respiration Disorders / Q000503:physiopathology / Q000628:therapy; D012121:Respiration, Artificial / Q000009:adverse effects*; D012680:Sensitivity and Specificity; D013990:Tidal Volume / Q000502:physiology
keywords: Fluid responsiveness; Heart-lung interaction; Patient-ventilator asynchrony; Pressure support ventilation; Pulse pressure variation