Optoelectronic vital capacity measurement for restrictive diseases.
OBJECTIVE
To determine whether optoelectronic plethysmography accurately evaluated vital capacity (VC) in patients with respiratory muscle dysfunction of variable severity, including those with paradoxical abdominal movements.


METHODS
In 20 subjects, VC was measured in the supine position using both spirometry and optoelectronic plethysmography (6 optoelectronic cameras and 52 reflective markers on the anterior chest wall).


RESULTS
Spirometry VC (VC-Spiro) correlated positively with optoelectronic VC (VC-Opto) (r(2) = 0.99, P < .001), and the regression line was very close to the identity line (VC-Opto [mL] = -1.202 + 1.007 × VC-Spiro [mL]). A Bland-Altman plot showed that the mean difference was -20 mL (95% CI -63 mL to 24 mL) and the limits of agreement were 163 mL (95% CI 106 mL to 231 mL) and -203 mL (95% CI -271 mL to -146 mL). The difference between the 2 values expressed as the percentage of the mean value was < 15% in all 20 subjects, < 10% in 17 (85%) subjects, and < 5% in 11 (55%) subjects. The difference, expressed as the percentage of the mean value, was unrelated to the contribution of abdominal motion to VC (r = 0.02 and P = .94), but was significantly related to body mass index (r = 0.53, P = .02).


CONCLUSIONS
Optoelectronic plethysmography is accurate and suitable for VC measurement in patients with various degrees of respiratory failure, including those with paradoxical abdominal movements. This noninvasive method may be an attractive alternative for accurately measuring VC in the event of air leakage (through the mouth or tracheostomy) or when patients are unable to breathe with the dead space added by the spirometer.
Services de Physiologie-Explorations Fonctionnelles, Plateforme d'Analyse du Mouvement, et Centre d'Innovations Technologiques, Unité Mixte de Recherche 805, Hôpital Raymond Poincaré, Assistance Publique Hôpitaux de Paris, Garches, France.
Julien
J
Boudarham
Didier
D
Pradon
Hélène
H
Prigent
Isabelle
I
Vaugier
Frédéric
F
Barbot
Nadège
N
Letilly
Line
L
Falaize
David
D
Orlikowski
Michel
M
Petitjean
Frédéric
F
Lofaso
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010991:Plethysmography; D015203:Reproducibility of Results; D012131:Respiratory Insufficiency / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D015656:Respiratory Mechanics / Q000502:physiology*; D012132:Respiratory Muscles / Q000503:physiopathology; D013147:Spirometry; D035441:Thoracic Wall; D014797:Vital Capacity; D055815:Young Adult