RT Journal Article
SR Electronic
T1 Risk factors and prognostic impact of decreased breathing variability in mechanically ventilated patients. A prospective study
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP OA4476
DO 10.1183/13993003.congress-2015.OA4476
VO 46
IS suppl 59
A1 Camille Rolland-Debord
A1 Côme Bureau
A1 Marc Clavel
A1 Sebastien Perbet
A1 Nicolas Terzi
A1 Achille Kouatchet
A1 Thomas Similowski
A1 Alexandre Demoule
YR 2015
UL http://erj.ersjournals.com/content/46/suppl_59/OA4476.abstract
AB Rational: Mechanical ventilation decreases the natural variability of major descriptors of the breathing pattern such as tidal volume (VT), inspiratory time (Ti), respiratory rate (RR) and mean inspiratory flow (Vt/Ti). Few studies have investigated the risk factors and the impact of a decreased variability on the outcome.Study aims: to identify risk factors of decreased breathing variability,to describe the consequences of a decreased breathing variability on the outcome.Methods: Ancillary study of a randomized controlled trial comparing neurally ventilator adjusted assist to pressure support ventilation in 127 patients. VT, RR and Vt/Ti were computed from the flow signal recordings and their respective coefficients of variation (CV) were calculated. Subjects were classified as having high or low variability pattern according to a cut-off determined by the respective median of each CV.Results: Mean coefficient of variation for RR, VT, VT/Ti was respectively 0.22 ± 0.09, 0.21 ± 0.10 and 0.17 ± 0,12. Age was significantly lower in patients with a high CV for RR compared to those with a low CV (65±13 vs.70±11, p= 0.038). No other significant difference was observed in term of gender, severity score (SAPS II), dyspnea, comfort and mechanical ventilation duration before inclusion between patients with a high or low CV. No significant difference was found between patients with high and low variability in term of on D28 mortality, duration of mechanical ventilation and length of stay.Conclusion: Among all factors, only age was associated with a decrease of breathing variability. Decrease of breathing variability was not associated with an alteration of the outcome.