PT - JOURNAL ARTICLE AU - Paisani, Denise de Moraes AU - Lunardi, Adriana Claudia AU - Marques da Silva, Cibele Cristine Berto AU - Porras, Desiderio Cano AU - Tanaka, Clarice AU - Carvalho, Celso Ricardo Fernandes TI - Volume Rather Than Flow Incentive Spirometry Is Effective in Improving Chest Wall Expansion and Abdominal Displacement Using Optoelectronic Plethysmography AID - 10.4187/respcare.02037 DP - 2013 Aug 01 TA - Respiratory Care PG - 1360--1366 VI - 58 IP - 8 4099 - http://rc.rcjournal.com/content/58/8/1360.short 4100 - http://rc.rcjournal.com/content/58/8/1360.full AB - BACKGROUND: Incentive spirometers are widely used in clinical practice and classified as flow-oriented (FIS) and volume-oriented (VIS). Until recently the respiratory inductive plethysmography used to evaluate the effects of incentive spirometry on chest wall mechanics presented limitations, which may explain why the impact of VIS and FIS remains poorly known. OBJECTIVE: To compare the effects of VIS and FIS on thoracoabdominal mechanics and respiratory muscle activity in healthy volunteers. METHODS: This cross-sectional trial assessed 20 subjects (12 female, ages 20–40 years, body mass index 20–30 kg/m2). All subjects performed 8 quiet breaths and 8 deep breaths with FIS and VIS, in a randomized order. We measured thoracoabdominal chest wall, upper and lower rib-cage, and abdominal volumes with optoelectronic plethysmography, and the muscle activity of the sternocleidomastoid and superior and inferior intercostal muscles with electromyography. RESULTS: VIS increased chest wall volume more than did FIS (P = .007) and induced a larger increase in the upper and lower rib-cages and abdomen (156%, 91%, and 151%, respectively, P < .001). By contrast, FIS induced more activity in the accessory muscles of respiration than did VIS (P < .001). CONCLUSIONS: VIS promotes a greater increase in chest wall volume, with a larger abdominal contribution and lower respiratory muscle activity, than does FIS in healthy adults.