ABSTRACT
Objective Since many years it has been conjectured that tracheotomy/tracheostomy interferes with swallowing and leads to a higher risk of aspiration. The aim of this review was to contribute to the discussion whether there is a causal relationship between tracheotomy/tracheostomy and dysphagia or only a chronological concomitance. Material and Methods Citations for this review rest upon a research in PubMed data base of the National Center for Biotechnology Information (NCBI). Results Effects of tracheostomy/tracheotomy as well as effects of different cannulas on motoric and sensory aspects of deglutition have been reviewed. Most papers focused on aspiration. Reported data were extremely heterogeneous. Finally no causal relationship between tracheotomy and dysphagia could be demonstrated. Conclusions Tracheo(s)tomized patients require a special awareness in respect to concomitant dysphagia. However, swallowing problems are considered to be primarily caused rather by underlying diseases than by the existence of the tracheostomy itself.
Subject(s)
Deglutition Disorders/diagnosis , Deglutition Disorders/etiology , Postoperative Complications/diagnosis , Postoperative Complications/etiology , Tracheotomy , Animals , Diagnosis, Differential , Disease Models, Animal , Humans , Risk FactorsABSTRACT
Distortion product otoacoustic emissions (DPOAEs) are widely used as an objective examination procedure to determine cochlear function. In a clinical routine setting, the amplitude of the DPOAE signal at 2f1 .. f2 is applied as an indicator for a potential hearing loss up to 8 kHz. Due to their poor signal to noise ratio, meatal nodes from standing waves and calibration issues, high-frequency DPOAEs > 8 kHz have hardly been addressed in experimental and clinical audiology so far. Here, we present a new method of measuring DPOAE signal levels based on optimal maximum likelihood estimation with windowed power spectral density estimation of stochastic signals and filtering theory. Analysis of simulated data showed that the proposed method effectively reduces the disturbing noise floor compared to conventional averaging techniques. Robust DPOAE signals were measured in 20 ears from 10 normally hearing young adults (21 to 27 years) from 0:5 to 18 kHz. Repeated DPOAE recordings in one individual yielded a good to very good testretest reliability of the proposed method. These observations are discussed in the context of DPOAE signal processing and possible clinical applications of high-frequency DPOAE measurements.
