[Subjective and objectifying olfactometry by means of flow-olfactometer].

BACKGROUND

Is the flow-olfactometer OM2S suitable for subjective and objectifying screening of olfactory function, additional to its use for chemosensory evoked potentials?

METHODS

53 normosmics were challenged prenasally and synchronously with inspiration by two short weak, moderate and strong hydrogen sulfide (H (2)S)- and phenylethyl alcohol (PEA)-stimuli. The subject pressed a button if there was an olfactory perception. The respiratory nasal pressure changes were recorded continuously via a differential pressure transducer. The alterations of breathing pattern during olfactory stimulation were calculated using a custom made LabView software. The interstimulus interval was at least 3 minutes, the respiration had to be regular.

RESULTS

The detection-rate (79 - 98 %) was dependent on quality of odor and its concentration during stimulation. H (2)S-stimuli were detected more frequently than PEA-stimuli. The frequency of detection with simultaneous alteration of breathing pattern was independent of quality of odor and strength of odor concentration. 64 % of the subjects detected both weak H (2)S as well as changed synchronously their first poststimulatory breath.

CONCLUSION

The H (2)S-detection threshold was estimated both by subjective data and by data of olfactory evoked respiration changes. The flow-olfactometer by Kobal is very well suitable for subjective and respiration-olfactometry, too.