Comparison of thoracoabdominal asynchrony estimated via optolectronic and inductive respiratory plethymographies

Thoracoabdominal asynchrony (TAA) is defined as the no coincident motion of ribcage (RC) and abdomen (AB) and considered as relevant clinically. TAA has been estimated through respiratory inductive plethysmography (RIP) and, more recently, optoelectronic plethysmography (OEP). However, the agreement of TAA measurements with both RIP and OEP remains unknown. OBJECTIVE: To compare TAA values during inspiration via OEP and RIP. METHODS: 8 healthy subjects (4 male, 34.2±8.7yrs and FEV 1 91.8±7.2%pred) performed 2 cycle ergometer sessions with 30 minutes between them in a random order. TAA was evaluated in different phases of exercise, 3 minutes of each one: at rest, 40% (L 40 ), 60% (L 60 ) and 80% (L 80 ) of maximal workload obtained in a previous day. TAA was calculated between RC (upper RC in OEP) and AB through phase angle using the Lissajous approach (Agostini and Mognoni, 1966). The flow at the mouth was assessed with a pneumotacograph. It was analyzed a mean cycle of 5 last breaths of every phase. RESULTS: The minute ventilation (V e ) and the pattern of breathing were homogeneous in OEP and RIP for rest and all phases of exercise. TAA was very similar in both approaches not only at rest but also in L 40 , L 60 and L 80 [Table1]. CONCLUSION: Thoracoabdominal asynchrony obtained by OEP or RIP results in similar values at rest and even for different exercise intensities.