On-line monitoring of lung mechanics during spontaneous breathing: a physiological study.
BACKGROUND
Monitoring the mechanics of breathing in patients with advanced chronic obstructive lung diseases prior to lung transplantation is useful to characterize changes in the mechanical properties of the lungs. On-line methods of monitoring immediately process the data for clinical decisions. However, the few available methods are so far limited to monitor respiratory mechanics in ventilator-dependent patients. We investigated whether on-line monitoring of the lung mechanics, including intrinsic PEEP, was feasible in spontaneously breathing patients.


METHODS
In 9 stable patients with chronic obstructive pulmonary disease (COPD) and 11 with cystic fibrosis (CF) undergoing the procedure for the lung transplantation waiting list, we applied 2 methods of on-line monitoring (modified recursive least squares, RLS and modified multiple linear regression methods, SLS) of intrinsic PEEP (P(0)), dynamic lung elastance (E(Ldyn)) and inspiratory resistance (R(Linsp)), and compared them with an off-line graphical analysis (GA), our reference technique.


RESULTS
In CF patients, there was no difference between methods, while in COPD, the median values of E(Ldyn) and R(Linsp) were significantly different between GA/SLS and GA/RLS, respectively (Dunn's, p<0.05). However, the correlation was very high for all comparisons, particularly for E(Ldyn) (R>0.98) and R(Linsp) (R>0.93). Moreover, Bland-Altman plots showed that the mean differences were consistently low and the intervals of agreement reasonable.


CONCLUSIONS
Our study suggests that on-line methods are reliable for monitoring lung mechanics in spontaneous breathing patients with severe lung diseases and could help clinicians in their decision-making process.
Khirani
Sonia
S
Pulmonary Division - A.O. Ospedali Riuniti di Bergamo, Bergamo, Italy. sonia_khirani@yahoo.fr
Polese
Guido
G
Aliverti
Andrea
A
Appendini
Lorenzo
L
Nucci
Gianluca
G
Pedotti
Antonio
A
Colledan
Michele
M
Lucianetti
Alessandro
A
Baconnier
Pierre
P
Rossi
Andrea
A
D000328:Adult; D003201:Computers; D003550:Cystic Fibrosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D012123:Pulmonary Ventilation / Q000502:physiology*; D015656:Respiratory Mechanics / Q000502:physiology*; D017216:Telemedicine