title: Optimization of ventilator setting by flow and pressure waveforms analysis during noninvasive ventilation for acute exacerbations of COPD: a multicentric randomized controlled trial.
abstract: BACKGROUND
  The analysis of flow and pressure waveforms generated by ventilators can be useful in the optimization of patient-ventilator interactions, notably in chronic obstructive pulmonary disease (COPD) patients. To date, however, a real clinical benefit of this approach has not been proven.
  
  
  METHODS
  The aim of the present randomized, multi-centric, controlled study was to compare optimized ventilation, driven by the analysis of flow and pressure waveforms, to standard ventilation (same physician, same initial ventilator setting, same time spent at the bedside while the ventilator screen was obscured with numerical data always available). The primary aim was the rate of pH normalization at two hours, while secondary aims were changes in PaCO2, respiratory rate and the patient's tolerance to ventilation (all parameters evaluated at baseline, 30, 120, 360 minutes and 24 hours after the beginning of ventilation). Seventy patients (35 for each group) with acute exacerbation of COPD were enrolled.
  
  
  RESULTS
  Optimized ventilation led to a more rapid normalization of pH at two hours (51 vs. 26% of patients), to a significant improvement of the patient's tolerance to ventilation at two hours, and to a higher decrease of PaCO2 at two and six hours. Optimized ventilation induced physicians to use higher levels of external positive end-expiratory pressure, more sensitive inspiratory triggers and a faster speed of pressurization.
  
  
  CONCLUSIONS
  The analysis of the waveforms generated by ventilators has a significant positive effect on physiological and patient-centered outcomes during acute exacerbation of COPD. The acquisition of specific skills in this field should be encouraged.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01291303.
authors: Pneumologia Ospedale San Paolo, Università degli Studi di Milano, via A, di Rudinì 8, Milano, 20142, Italy. fabiano.dimarco@unimi.it
authors: Fabiano
authors: F
authors: Di Marco
authors: Stefano
authors: S
authors: Centanni
authors: Andrea
authors: A
authors: Bellone
authors: Grazia
authors: G
authors: Messinesi
authors: Alberto
authors: A
authors: Pesci
authors: Raffaele
authors: R
authors: Scala
authors: Andreas
authors: A
authors: Perren
authors: Stefano
authors: S
authors: Nava
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D059725:Interactive Ventilatory Support / Q000379:methods*; D008297:Male; D011175:Positive-Pressure Respiration; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology / Q000628:therapy*; D011659:Pulmonary Gas Exchange / Q000502:physiology; D056152:Respiratory Rate; D016896:Treatment Outcome