Validation of respiratory inductive plethysmography (LifeShirt) in obesity hypoventilation syndrome

Validation of respiratory inductive plethysmography (LifeShirt system) (RIPLS) for tidal volume (V-T), minute ventilation ((V) over dot(E)), and respiratory frequency (f(B)) was performed among people with untreated obesity hypoventilation syndrome (OHS) and controls. Measures were obtained simultaneously from RIFLE and a spirometer during two tests, and compared using Bland Altman analysis. Among 13 OHS participants (162 paired measures), RIPLS-spirometer agreement was unacceptable for V-T: mean difference (MD) 3 mL (1%); limits of agreement (LOA) -216 to 220 mL (+/- 36%); (V) over dot(E) MD 0.1 L min(-1) (2%); LOA -4.1 to 4.3 L min(-1) (+/- 36%); and f(B): MD 0.2 br min(-1) (2%); LOA -4.6 to 5.0 br min(-1) (+/- 27%). Among 13 controls (197 paired measures), RIPLE-spirometer agreement was acceptable for f(B): MD -0.1 br min(-1) (-1%); LOA -1.2 to 1.1 br min(-1) (+/- 12%), but unacceptable for V-T: MD 5 mL (1%); LOA -160 to 169 mL (+/- 20%) and (V) over dot(E): MD 0.1 L min(-1) (1%); LOA -1.4 to 1.5 L min(-1) (+/- 20%). RIPLS produces valid measures of f(B) among controls but not OHS patients, and is not valid for quantifying respiratory volumes among either group. (C) 2014 Elsevier B.V. All rights reserved.