Open AccessNoninvasive assessment of respiratory resistance in severe chronic respiratory patients with nasal CPAP
Author(s) -
Farré R.,
Gavela E,
Rotger M.,
Ferrer M,
Roca J,
Navajas D.
Publication year - 2000
Publication title -
european respiratory journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.021
H-Index - 241
eISSN - 1399-3003
pISSN - 0903-1936
DOI - 10.1034/j.1399-3003.2000.15b16.x
Subject(s) - supine position , medicine , sitting , respiratory system , continuous positive airway pressure , anesthesia , airway resistance , respiratory disease , cardiology , lung , obstructive sleep apnea , pathology
Noninvasive measurement of respiratory resistance during nasal ventilatory support could be useful to assess the mechanical status of the patient and to optimize the ventilator settings. The aim was to investigate whether the forced oscillation technique (FOT) applied through a nasal mask allows reliable noninvasive estimation of respiratory resistance ( R rs) in patients with severe chronic respiratory disease. FOT R rs (5 Hz) and lung resistance ( R L) measured simultaneously from spontaneous breathing signals by an oesophageal balloon were compared in eight patients with chronic obstructive pulmonary disease and in six patients with a restrictive ventilatory defect due to chest wall disease. Measurements were performed in sitting and supine postures during application of nasal continuous positive airway pressure (CPAP): 4, 8 and 12 cmH 2 O in obstructive patients and 4 cmH 2 O in restrictive patients. In the restrictive patients R rs and R L (in cmH 2 O·s·L ‐1 ) were virtually coincident: mean± sd , 12.6±6.1 and 11.6±6.6 (r=0.96) in sitting and 9.7±3.1 and 10.2±3.3 (r=0.92) in supine posture, respectively. In the obstructive patients (CPAP = 4 cmH 2 O), R rs slightly underestimated R L: mean± sd , 11.5±5.9 and 14.4±16.8 (r=0.92) in sitting and 15.0±9.8 and 21.1±12.6 (r=0.96) in supine posture, respectively. Similar results were found at CPAP = 8 and 12 cmH 2 O. The results obtained in patients with resistance values in the range typically found in nasal ventilatory support suggest that forced oscillation technique could be valuable to noninvasively estimate a patient′s respiratory mechanical resistance.