Grommets (ventilation tubes) for hearing loss associated with otitis media with effusion in children.

BACKGROUND: Otitis media with effusion (OME), or 'glue ear', is very common in children, especially between the ages of one and three years with a prevalence of 10% to 30% and a cumulative incidence of 80% at the age of four years. OME is defined as middle ear effusion without signs or symptoms of an acute infection. OME may occur as a primary disorder or as a sequel to acute otitis media. The functional effect of OME is a conductive hearing level of about 25 to 30 dB associated with fluid in the middle ear. Both the high incidence and the high rate of spontaneous resolution suggest that the presence of OME is a natural phenomenon, its presence at some stage in childhood being a normal finding. Notwithstanding this, some children with OME may go on to develop chronic otitis media with structural changes (tympanic membrane retraction pockets, erosion of portions of the ossicular chain and cholesteatoma), language delays and behavioural problems. It remains uncertain whether or not any of these findings are direct consequences of OME. The most common medical treatment options include the use of decongestants, mucolytics, steroids, antihistamines and antibiotics. The effectiveness of these therapies has not been established. Surgical treatment options include grommet (ventilation or tympanostomy tube) insertion, adenoidectomy or both. Opinions regarding the risks and benefits of grommet insertion vary greatly. The management of OME therefore remains controversial. OBJECTIVES: To assess the effectiveness of grommet insertion compared with myringotomy or non-surgical treatment in children with OME. The outcomes studied were (i) hearing level, (ii) duration of middle ear effusion, (iii) well-being (quality of life) and (iv) prevention of developmental sequelae possibly attributable to the hearing loss (for example, impairment in impressive and expressive language development (measured using standardised tests), verbal intelligence, and behaviour). SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2003), MEDLINE (1966 to 2003), EMBASE (1973 to 2003) and reference lists of all identified studies. The date of the last systematic search was March 2003, and personal non-systematic searches have been performed up to August 2004. SELECTION CRITERIA: Randomised controlled trials (RCTs) evaluating the effect of grommets on hearing, duration of effusion, development of language, cognition, behaviour or quality of life. Only studies using common types of grommets (mean function time of 6 to 12 months) were included. DATA COLLECTION AND ANALYSIS: Data from studies were extracted by two reviewers and checked by the other reviewers. MAIN RESULTS: Children treated with grommets spent 32% less time (95% confidence interval (CI) 17% to 48%) with effusion during the first year of follow-up. Treatment with grommets improved hearing levels, especially during the first six months. In the randomised controlled trials that studied the effect of grommet insertion alone, the mean hearing levels improved by around 9 dB (95% CI 4 dB to 14 dB) after the first six months, and 6 dB (95% CI 3 dB to 9 dB) after 12 months. In the randomised controlled trials that studied the combined effect of grommets and adenoidectomy, the additional effect of the grommets on hearing levels was improvement by 3 to 4 dB (95% CI 2 dB to 5 dB) at six months and about 1 to 2 dB (95% CI 0 dB to 3 dB) at 12 months. Ears treated with grommets had an additional risk for tympanosclerosis of 0.33 (95% CI 0.21 to 0.45) one to five years later. In otherwise healthy children with long-standing OME and hearing loss, early insertion of grommets had no effect on language development or cognition. One randomised controlled trial in children with OME more than nine months, hearing loss and disruptions to speech, language, learning or behaviour showed a very marginal effect of grommets on comprehensive language. AUTHORS' CONCLUSIONS: The benefits of grommets in children appear small. The effect of grommets on hearing diminished during the first year. Potentially adverse effects on the tympanic membrane are common after grommet insertion. Therefore an initial period of watchful waiting seems to be an appropriate management strategy for most children with OME. As no evidence is yet available for the subgroups of children with speech or language delays, behavioural and learning problems or children with defined clinical syndromes (generally excluded from the primary studies included in this review), the clinician will need to make decisions regarding treatment for such children based on other evidence and indications of disability related to hearing impairment. This review does not resolve the discrepancy between parental and clinical observation of a beneficial treatment effect and the results in the reviewed RCT showing only a short-term effect on hearing and virtually no effect on development. Is the perceived, often dramatic, effect of grommets only a short-term one? Are some children more sensitive to OME-related hearing loss than others? If so, how do we identify them?Further research should focus upon indications. Studies should use sufficiently large sample sizes to show significant interactions. There is a need to determine the most suitable variables and appropriate "softer" outcomes to be the subject of these interaction tests. Interesting options include measures of speech-in-noise and binaural hearing. The generally modest results in the trials which are included in this review should make it easier to justify randomisation of more severely affected and higher-risk children in appropriately constructed trials. Randomised controlled trials are necessary in these children before more detailed conclusions about the effectiveness of grommets can be drawn.

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).

[Tympanometry]. / Tympanometri.

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.

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.

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.

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.

Preparation of oligodeoxyribonucleoside phosphorodithioates by a triester method.

A method to prepare thymidine phosphorodithioate dimers (ref. 1) has been extended to allow the preparation of oligo-2'-deoxyribonucleotide phosphorodithioates containing all four bases. The method is suitable for large-scale synthesis and gives phosphorodithioates without phosphorothioate impurities (31P nmr, detection limit 0.5 to 1%). Oligonucleotides up to octamers which contain -0-(PS2-)-0- linkages at all positions have been prepared by block synthesis in solution. The phosphorodithioate linkage is introduced by the reaction of a 5'-O, N-protected nucleoside (or oligonucleotide) with a dithiophosphorylating agent RSP(S)(ODhbt)2, R = 2,4-dichlorobenzyl, Dhbt = 3,4-dihydro-4-oxo-benzotriazin-3-yl, followed by coupling of the product to a 3'-O,N-protected nucleoside (or oligonucleotide). This method gives pure protected oligodeoxyribonucleoside phosphorodithioates, and phosphorothioate linkages are only introduced if contact with conc. aqueous ammonia during or after deblocking is unduly prolonged.

[Diagnosis and treatment of ear diseases in general practice. A controlled trial of the effect of the introduction of middle ear measurement (tympanometry)]. / Diagnostik og behandling af øresygdomme i almen praksis. En kontrolleret undersøgelse af virkningen af indførelse af mellemøretrykmåling (tympanometri).

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.

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.

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.

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.

Human leukocyte antigen-A, -B, -C tissue types in patients with middle ear cholesteatoma.

Two series of consecutive, nonrelated patients with middle ear cholesteatoma verified by operation were tissue typed for human leukocyte antigens (HLAs) in order to demonstrate any associations. The first series (102 patients) showed only a possible increase of HLA-B8 and HLA-A2. Because HLA-B8 is one of the antigens most often involved in associations with organ-specific autoimmune diseases, and because of the close relationship between HLA-B8 and HLA-DR3, the second series (48 patients) was tissue typed for these two antigens. This second series showed a similar increase of HLA-B8/DR3, but the difference was not statistically significant.

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.

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.