Effort sensation, chemoresponsiveness, and breathing pattern during inspiratory resistive loading

ingpattern during inspiratory resistive loading. J. Appl. Physiol. 73 ( 2): 440-445, 1992.-Although inspiratory resistive loading (IRL) reduces the ventilatory response to CO, (ir~IPco & and increases the sensation of inspiratory effort (IES), there are few data about the converse situation: whether COZ responsive-ness influences sustained load compensation and whether awareness of respiratory effort modifies this behavior. We stud-ied 12 normal men during CO2 rebreathing while free breathing and with a 100cmH,O l 1-l. s IRL and compared these data with 5 min of resting breathing with and without the IRL. Breathing pattern, end-tidal Pco,, IES, and mouth occlusion pressure (P,,) were recorded. Free-breathing ~E/Pco ~ was inversely re-lated to an index of effort perception (IES/~TE; r =-0.63, P < 0.05), and the reduction in ~EIP~o ~ produced by IRL was related to the initial free-breathing VE/PCO, (r = 0.87, P &lt