title: Patient-ventilator asynchronies: may the respiratory mechanics play a role?
abstract: BACKGROUND
  The mechanisms leading to patient/ventilator asynchrony has never been systematically assessed. We studied the possible association between asynchrony and respiratory mechanics in patients ready to be enrolled for a home non-invasive ventilatory program. Secondarily, we looked for possible differences in the amount of asynchronies between obstructive and restrictive patients and a possible role of asynchrony in influencing the tolerance of non-invasive ventilation (NIV).
  
  
  METHODS
  The respiratory pattern and mechanics of 69 consecutive patients with chronic respiratory failure were recorded during spontaneous breathing. After that patients underwent non-invasive ventilation for 60 minutes with a "dedicated" NIV platform in a pressure support mode during the day. In the last 15 minutes of this period, asynchrony events were detected and classified as ineffective effort (IE), double triggering (DT) and auto-triggering (AT).
  
  
  RESULTS
  The overall number of asynchronies was not influenced by any variable of respiratory mechanics or by the underlying pathologies (that is, obstructive vs restrictive patients). There was a high prevalence of asynchrony events (58% of patients). IEs were the most frequent asynchronous events (45% of patients) and were associated with a higher level of pressure support. A high incidence of asynchrony events and IE were associated with a poor tolerance of NIV.
  
  
  CONCLUSIONS
  Our study suggests that in non-invasively ventilated patients for a chronic respiratory failure, the incidence of patient-ventilator asynchronies was relatively high, but did not correlate with any parameters of respiratory mechanics or underlying disease.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Carlucci
authors.forename: Lara
authors.initials: L
authors.lastname: Pisani
authors.forename: Piero
authors.initials: P
authors.lastname: Ceriana
authors.forename: Alberto
authors.initials: A
authors.lastname: Malovini
authors.forename: Stefano
authors.initials: S
authors.lastname: Nava
mesh_terms: D000368:Aged; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000379:methods* / Q000592:standards; D012131:Respiratory Insufficiency / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*; D015656:Respiratory Mechanics / Q000502:physiology*