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Biomedical subjects

J U Felding

Publications and source records attributed to J U Felding.

At least 19 recordsLinked to original sources
PubMed2000

[Tympanometry].

A flat tympanogram predicts a middle ear effusion in about 90% of cases. This paper describes how to perform tympanometry, some common problems when doing it and how to classify the curves in normal (type A), middle ear effusion (type B) or negative pressure (type C). The theoretical background of impedance audiometry is outlined. The stapedius reflex, pneumatic otoscopy, reflexometry and otomicroscopy are described as supplements or alternatives in diagnosing fluid in the middle ear. Tympanometry is recommended as a diagnostic modality for general practitioners.

Acoustic Impedance Tests↗
PubMed2000

Effect of N-acetylcysteine on the incidence of recurrence of otitis media with effusion and re-insertion of ventilation tubes.

Previous studies have demonstrated the anti-inflammatory, anti-oxidant, and mucolytic nature of N-acetylcysteine (NAC). Theoretically, these properties make the substance ideal for therapeutic use against otitis media with effusion (OME). The disease is characterized as a sustained non-specific inflammation of the middle ear mucosa with secretory transformation of the epithelium resulting in accumulation of fluid in the middle ear space. To investigate the effects of instillation of NAC in the middle ear, a double-blind, placebo-controlled, randomized trial was carried out. A total of 75 children who were undergoing their first bilateral insertion of ventilation tubes (VT) due to OME were randomized to Mucomyst (NAC) or placebo (the vehicle) on one ear in relation to the VT insertion. The contralateral ear underwent VT insertion exclusively. Instillation of Mucomyst or placebo was repeated 3 and 7 days afterwards. The children were followed regularly for 11-39 months. Episodes of otorrhea, recurrence of OME after VT extrusion and re-insertion of VTs were registered as primary outcome parameters. The results demonstrated that Mucomyst significantly reduced the recurrence of OME and re-insertion of VTs (p < 0.025) and significantly increased the time until VT extrusion (p < 0.0167). In addition, the number of episodes of ear problems and visits at the ENT clinic were reduced significantly by NAC (p < 0.0383).

Acetylcysteine↗
PubMed1995

The biochemical characteristics of the middle ear system measured by a new method. I: Instrumentation.

A frequent finding in patients with earlier otitis media is the sequelae of tympanic membrane atrophy and sclerosis. A major number of these patients nevertheless present with normal audiometric and tympanometric findings. In search of an objective and quantitative description of these pathological changes a new instrument has been developed to measure pressure changes in the ear canal as a function of dynamic tympanic membrane volume displacement. This pressure-volume relationship of the middle ear system expresses non-linear behaviour and hysteresis, which is due to loss of energy under dynamic conditions. Hysteresis can be measured and is here introduced as a new mechanical variable of the middle ear system along with dynamic compliance. Hysteresis is expressed in microJ and compliance in microliter/cmH2O. Analytical measurements of the instrument were found to be small compared with clinical values (< 2.8%). This paper will be succeeded by another study presenting the clinical application of the method and a normal material.

Biomechanical Phenomena↗
PubMed1995

The biomechanical characteristics of the middle ear system measured by a new method. II: Clinical application and normal material.

An instrument for measuring the pressure-volume relationship of the middle ear system was introduced earlier. This paper describes the practical application of the instrument and presents a normal material of 45 healthy young adults. Reflecting a slight increase in pressure in the ear canal during the measuring procedure, a series of curves is obtained, each representing a different position of the tympanic membrane. From these curves the zero curve is defined, representing the zero position of the drum. This curve is used to determine the variables of the pressure-volume relationship of the middle ear system: hysteresis, pressure range, Pec0, and compliance. The variables express objective and dynamic measures of the mechanical properties of the middle ear. The method had an acceptable repeatability and was found to be consistent with earlier investigations. It is easy to perform and causes the subject no discomfort. It is therefore considered useful for further investigation of middle ear physiology and pathophysiology.

Adult↗
PubMed1995

Biomechanical characteristics of the middle ear system measured by a new method. III: Comparisons with tympanometric measurements.

A new method for studying middle ear mechanics is reported in which we measured ear canal pressure changes due to tympanic membrane volume displacements. One feature of this pressure-volume relationship (PVR) is the determination of dynamic compliance of the middle ear system (MES). We found a significant correlation between dynamic compliance expressed by the PVR and static acoustic compliance by tympanometry. Another feature of the PVR was determination of the mechanical zero position of the tympanic membrane (TM) defined in terms of minimum hysteresis, which correlated significantly with the neutral position of the TM determined by tympanometry, but indicates a retracted position of the TM relative to tympanometry. Finally the hysteresis effect of the MES measured with the PVR was compared and found to fall within the range of peak difference found in bidirectional tympanometric recordings, which is also influenced by phase delay and semi-dynamic conditions.

Acoustic Impedance Tests↗
PubMed1991

[Diagnosis and treatment of ear diseases in general practice. A controlled trial of the effect of the introduction of middle ear measurement (tympanometry)].

The diagnosis and treatment of diseases of the ear in general practice could be rendered optimal by employing tympanometry (measurement of the pressure in the middle ear) which is already known from specialist practice. This was investigated by means of a controlled investigation with cooperation between general practice, otologists and the health services in the County of Vejle. Following randomizing among 20 general practitioners, ten were trained in tympanometry (the test group) while ten did not change their principles for diagnosis and treatment (control group). The criteria for inclusion in the investigation were the findings of indications for otoscopy in children under the age of 16 years. During a period of 12 months, parallel registrations of the data were made in the two groups and 3,166 children with an average age of 3.4 years were included. The clinical course showed statistically significant differences (p less than 0.05) between the groups as regards diagnosis and treatment: acute otitis media was found in 8.4% in the control group and 2.6% in the test group. Secretory otitis media (glue ear) was found in 14.2% in the control group and in 25% in the test group. Correspondingly, penicillin was prescribed for 7.6% in the control group and 4.1% in the test group. The otologists performed tubulation of the tympanic membrane in 0.9% in the control group and 3.2% in the test group. Continued investigations are necessary to elucidate whether tympanometry should be part of the daily routine in general practice.

Acoustic Impedance Tests↗
PubMed1991

Acoustic rhinometry used as a method to monitor the effect of intramuscular injection of steroid in the treatment of nasal polyps.

Acoustic rhinometry is a new method which describes the geometry of the nasal cavity and the epipharynx. The method, based on the reflection of an acoustic signal entered into the nasal cavity, can be used to evaluate the cross-sectional area of the nasal cavity as a function of distance from the nostril. The method has, together with nasal expiratory peak flow (NPF) and nasal index based upon a self assessment score, been used to evaluate, in an objective and dynamic way, the effect of systemic treatment of nasal polyps with steroids in a series of eight patients with recurrent nasal polyposis. The study shows a significant relationship between these three parameters before and after systemic treatment of nasal polyps with steroids. It is concluded that in this study acoustic rhinometry had an accurate and objective method for measuring the geometry of the nasal cavity before and after treatment for processes which block the nasal cavity.

Acoustics↗
PubMed1991

Acoustic rhinometry, used as a method to demonstrate changes in the volume of the nasopharynx after adenoidectomy.

Acoustic rhinometry is a method of investigating the geometry of the nasal cavity and the nasopharynx. An acoustic impulse is transferred to the nasal cavity and the reflected signal is analysed expressing the cross-sectional area in the nasal cavity and the nasopharynx as a function of the distance from the nostril. The method provides an accurate and objective measurement of the geometry of the nasal cavity and the nasopharynx in a non-invasive way. In a series of 20 children, age range 4-16 years, it has been possible to demonstrate the changes in the volume of the nasopharynx after adenoidectomy. The relation between the volume of the adenoid and the calculated change of volume in the nasopharynx is found to be proportional and highly significant (P = 0.0005). It is concluded that acoustic rhinometry, which is very easy to perform, gives a reliable, objective measurement of the amount of adenoid tissue in the nasopharynx. The results from these and future studies may help reduce the number of unnecessary adenoidectomies.

Adenoidectomy↗
PubMed1991

Stapes surgery: complications and airway infection.

From a group of 1,111 patients who had stapedectomy or stapedotomy performed in a 10-year period, a thorough investigation was made of 11 patients who had a total hearing loss and 8 patients who developed a partial sensorineural hearing loss after operation. The data obtained indicate that postoperative infection with influenza virus may be responsible for unexpected complications following stapedectomy. A close relation was found between the appearance of complications and periods of epidemics of influenza.

Adolescent↗
PubMed1987

Reinke's oedema and thyroid function: a prospective study in 43 patients.

This study was designed to analyse thyroid function in patients with Reinke's oedema. Among 43 patients, 2 new cases of myxoedema as well as 2 patients with borderline myxoedema were found. However, the majority of patients showed no indication of thyroid hypofunction. In addition the alcian-blue staining intensity of vocal cord biopsies from patients with Reinke's oedema was compared with thyroid parameters, but a relation was not found.

Adult↗
PubMed1987

Gas composition of the normal and the ventilated middle ear cavity.

Epidemiologic and controlled studies indicate that late minimal hearing impairment is a sequelae after the use of a ventilation tube in early childhood. The patho-physiology is unknown, but abnormal middle ear gas composition might be important. Therefore it is mandatory to measure middle ear gas composition in order to understand the gas exchange in the normal middle ear, as well as the change in gas composition associated with ventilation tubes. Accordingly, the aim of this study was to measure middle ear gas composition both in the physiologic state and in artificial ventilation by a transtympanic tube. Employing puncture of the typanic membrane, through a liquid seal, we aspirated 300 microliters of middle ear gas. The procedure was carried out under the otomicroscope on adults without any anesthesia. A total of 58 normals participated, along with 10 persons with unilateral ventilation tubes and 1 with a patent Eustachian tube. The mean values of physiologic state were: Partial pressure of oxygen in the middle ear cavity = 39 mm Hg, and partial pressure of carbondioxide in the middle ear cavity = 48 mm Hg. The mean values of artificially ventilated ears were: Partial pressure of oxygen in the middle ear cavity = 138 mm Hg, and partial pressure of carbondioxid in the middle ear cavity = 15 mm Hg. The total imprecision was 4.2/4.4 mm Hg and the accuracy seems fair,--especially because we found a quasi equilibrium to the "most probable value", the venous blood gases. It is concluded that artificial ventilation of the middle ear cavity, with a ventilation tube increases the oxygen content of the middle ear cavity with a factor 3.2. This constitutes a relative hyperoxic atmosphere with a subsequent possibility for a toxic tissue damage.

Adolescent↗
PubMed1986

Efficacy of perioperative ceftazidime in the surgical treatment of chronic otitis media due to Pseudomonas aeruginosa. Preliminary report of a prospective, controlled study.

A prospective open and controlled study of perioperative antibiotics was conducted in patients with chronic otitis media (COM). Drug efficacy was found in a subgroup of 26 patients, who were characterized by preoperative aural drainage culturing Pseudomonas aeruginosa. Fourteen of these patients were randomized to receive ceftazidime (cephalosporin) for 5 days at the operation, while 12 had no antibiotic treatment. The occurrence of subsequent aural drainage was compared with the actual clinical and microbiological conditions of the ears 2 months after the operation; statistically significant differences were found in favor of the group treated with ceftazidime. Further studies must define the role of ceftazidime and other antibiotics in the management of patients with COM.

Adult↗
PubMed1985

The value of X-ray examination of the paranasal sinuses after epistaxis.

In a number of Danish ENT departments, X-ray examination of the paranasal sinuses has been a routine procedure in cases of severe epistaxis of uncertain genesis, two to four weeks after its treatment has been completed. The object has been to rule out cancer of the nose and/or paranasal sinuses. In the present study, the value of this procedure was assessed.

Acute Disease↗