Respiratory load compensation in uremia.

The clinical significance of respiratory-system load-compensation is unknown. We have measured the responses to random presentation of single, elastic inspiratory loads in 36 subjects: 8 normal personnel (N), 9 with obesity (O), 10 with chronic renal failure under hemodialysis (H), 5 with pneumonia (P), and 4 with interstitial lung disease (CILD). We have expressed these responses as: (1) the ratio of elastance (or rigidity) of the system during loaded breathing to the elastance without loading (E'RS/ERS); (2) the ratio of tidal volume (VT) achieved when breathing from an inspiratory load to the VT predicted in the absence of load compensation (VTL/VTP); (3) the ratio of inspiratory flow rates during loaded and unloaded breaths; (4) the ratio of inspiratory time of loaded and unloaded breaths.