PERCEPTION OF INFLATION OF A SINGLE-LUNG LOBE IN HUMANS

We tested whether subjects could detect and localize inflation confine d to a single lung lobe. A balloon-sealed catheter was placed into a l obar bronchus of unsedated subjects via fiberoptic bronchoscopy. Topic al anesthesia (lidocaine) was used to suppress cough and irritation as sociated with inflation of the sealing balloon. Small (45-60 ml) or la rge (100-240 ml) stimulus volumes were insufflated via the catheter. I n a forced-choice protocol, subjects were readily able to detect large inflations and correctly identify the side on which the stimulus was given, but small inflations were at the threshold of detection and wer e not correctly localized. Additional lidocaine applied to the bronchu s in two subjects did not degrade detection. Circumstantial evidence s uggests that the sensation arose in the lung. We conclude that this te chnique is feasible for the study of pulmonary perception. (C) 1997 El sevier Science B.V.