Otitis media with effusion

1. Otitis media with effusion vol-1
Definition : is the chronic accumulation of mucus within the middle ear & sometimes the mastoid air
cell system. The time that the fluid has to be present for the condition to be chronic is usually taken
as 12 weeks. In children, OME usually presents because of the associated hearing impairment &
sometimes with a preceding history of illness & otalgia consequent on an episode of acute otitis
media.
In the majority of children, acute otitis media is considered to have been triggered by a viral upper
respiratory tract infection that damages the epithelium of the Eustachian tube, resulting in
retention of middle ear fluid. These secretions then becomes secondarily infected with bacteria-
acute otitis media. Once the infection has resolved, it can take time for epithelium to recover.
Hence , OME will be present temporarily in many children after an episode of acute otitis media.
However, many children with OME have no recent history of acute otitis media, although they may
have had an upper respiratory tract infection. These damages the Eustachian tube epithelium with
resultant retention of middle ear fluid, which in these children does not become secondarily
infected.
Aetio-pathology of OME
Histology
The ciliated pseudostratified columnar epithelium of the respiratory tract extends up the Eustachian
tube as far as anterior part of the middle ear cavity. These cell are capable of producing mucus. In
addition there are goblet cells & mucus secreting glands. OME is primarily caused by an
inflammation of this epithelium in the Eustachian tube & hypotympanum.
Once OME has become established, the normal cuboidal & flat epithelium of middle ear & mastoid
mucosa is patchily replaced by pseudostratified mucus-secreting epithelium with goblet cells &
mucus secreting glands.
The submucosa is oedematous & inflamed with dilated blood vessels, increased number of
macrophages, plasma cells & lymphocytes.
Characteristics of the effusion
The fluid is characterized by its consistency as being either serous or mucoid. The full spectrum of
fluid types made up of a mixture of the secretions of the epithelial cell, goblet cells, mucus glands
along with the inflammatory transduate/ exudates which comes through the intracellular spaces
from the inflamed submucosa.
The main finding is that it is the mucins that come from the secretions that are responsible for the
variable viscosity of the middle ear fluid.

2. Bacteriology
No pathogens are detected after 6 months. OME fluid( more than 2 months duration) contains wide
spectrum of bacteria, streptococcus pneumonia, HI,Branhamella catarrhalis, streptococcus
pyogenes. The incidence of pathogens are higher
-in children less than two years.
-recurrent upper respiratory tract infection.
- recurrent attack of acute otitis media.
Eustachian tube dysfunction
The epithelium of ET is inflamed, oedematous & loss of cilia. The upper respiratory tract infection is
probably most common cause of ETD. It may be secondary to an allergic reaction or pollutants such
as cigarette smoke. It may be secondary to adenoidal infection or gastro-oesophageal reflux. It may
be due to disorder of the palatine muscles as in cleft palate.
Craniofacial abnormalities
Children with a cleft palate , even if repaired, have deficient palatine muscles & resultant poor
Eustachian tube function. As a consequence, OME is virtually universal in infants with a cleft palate
& surgical repair of the clefts does not influence the incidence.
The children with bifid uvula do not appear to have a higher incidence of OME.
Children with Down or Turner syndrome are more likely to have OME.
Allergy
The evidence does not support allergy as risk factor for the occurrence or persistent of OME.
Gatro-oesophageal reflux
Biochemical analysis of middle ear fluid in OME suggest that pepsin is present in a higher proportion
of effusions(approximately 80%). Further prospective investigations are required to clarify the role
of gastro-oesophageal reflux in childhood OME.
Epidemiology
Prevalence
In childhood OME, the main determinants of the prevalence are the age of the child & season of the
year.
Associated with age; the prevalence is bimodal with the first & largest peak of approximately 20% at
two years of age.(first attend the playgroup or nersury). The second peak of approximately 16% at
around five years of agewhen most children start attending a primary school.
By the age of seven to eight years, the prevalence falls.

3. A more recent study using a diagnostic algorithm of tympanometry & otoscopy, suggest that the
peak is more likely to be around one year of age.
Associated with season of the year:
In the temperature climates, the children are affected in winter season twice as opposed to the
summer months. the most likely cause are increased frequency of upper respiratory tract infection &
ear infection in the winter & close contact of the children.
In nontemperate countries, do not appear to be different overall from those in temperate countries.
Risk factors for occurance of OME under three years of age
1.Episodes of acute otitis media; recurrent episodes of acute otitis media are frequent & this is
likely to be the largest single factor for developing OME.
2.Contact with other children at home & play groups.
3.Heridiatbility :in children who had OME during first year of life, there was greater
concordance in monozygotic sets in the number& duration of OME episodes than in
dizygotic sets.
4.Race ; insufficient evidence to examine any effect of race.(no difference between black &
white).
5.Gender ; it is concluded that there is likely to be little difference , if any in the risk for boys
compared to girls.
6.Smoking ; the effect of parental smoking must be negligible.
Risk factors for occurrence in children older than three years
Episodes of acute otitis media are likely to be less important because of its lower prevalence in this
age group.
Duration & recurrence of episodes in children under the age of three years
Infant are twice as likely to develop unilateral as opposed to bilateral OME.
Unilateral at the start (one month later)
-50% resolved
-20% bilateral
-30% remained unilateral
Bilateral at the start(one month later)
-60% remained bilateral
-40% resolution.

4. Duration & recurrence of episodes in children older than three years
The proportion of unilateral to bilateral OME are equal. The overall recurrence rate is low(7%). Ear
first diagnosed to have OME between September & February(winter) persist longer than those first
diagnosed between March & Augest(summer).
Clinical applicability of best epidemiological evidence
The prevalence of OME in childhood is age depedent, with two peaks in the distribution ; one
centred around one to two years of age& other around three to seven years of age.
In temperate countries, twice as many children have OME in the winter as opposed to the summer.
The increased frequency of upper respiratory infections & close contact with other children during
the winter months contribute to this association.
Under three years of age, episodes of acute otitis media,contact with other children& heredity are
factors that increase the risk of recurrence.
Under three year of age, unilateral OME is twice as common as bilateral OME. Bilateral OME more
likely to persist than unilateral OME. Therefore most effort should be expended on children with
bilateral OME.
In primary care, children with bilateral OME & a history of upper respiratory infections are more
likely to persist.
In secondary care, children with bilateral OME seen in the second half of the year(July to December)
with a hearing impairment of 30dbHL in both ear are more likely to persist.
Diagnosis
The initial diagnosis in most cases of children OME will be by otoscopy. The otoscopic appearances
of OME are extremely variable but can be added by use of a pneumatic otoscope. In primary care
confirmed by tympanometry.in secondary care,investigations should be tympanometry &
audiometry.
Otoscopy
Unfortunately the otoscopic appearance of OME are extremely variable. Otoscopic findings in OME
are mainly different combinations of retraction of the pars tensa & variation of its colour.
Retraction may be evident by
1)indrawning of the handle of malleus( sade grade 3 retraction to the promontory, retraction
particularly evident inferiorly).
2) Presence of a neo-annular fold.
Colour change may be yellow & more blue or just clear. Fluid levels or air bubles are relatively
uncommon.

5. Pneumatic otoscopy
This can be carried out with a closed system in a handle-held otoscopic or with a siegle’s pneumatic
speculum viewed with headlight illumination or microscopic.
Video otoscopy
Video recordings of otoscopy, including pneumatic otoscopy , can be documented & used to
monitor changes with time. It can also be used for teaching & research purposes.
Free-field voice testing
In the primary care, audiometry is seldom available. The practitioner could perform free-field voice
testing of hearing.(use of pictures to point at or two syllable words).
Tympanometry
Tympanogram can be classified into peaked & non-peaked.
Peaked tympanogram again subclassification depending on pressure at which the peak is recorded.
Gold standard suggest that
1) a type B tympanogram is frequently associated with OME.
2)Type A is infrequently associated with OME.
3) Type C falls in between.
Type C2

Type C1 Type A
Type B
-400 -200 -100 0 +200
Pressure (mm of H2O)
Classification of tymapanograms
Type Description
Peaked A
C1
C2
Between +200 & -99dapa
Between -200 & -199dapa
Between -200 & -399dapa
Non –peaked B No observable peak between +200& -600dapa

6. Relationship between tympanogram type & effusion at myringotomy
Tympanogram No effusion Minimal Moderate Impacted
A 27% 36% 15% 22%
B 0% 12% 13% 75%
C 18% 35% 24% 23%
The anaesthetic can itself aerate the middle ear giving a false dry tap.
Audiometry
In the secondary care, audiometric assessment of the hearing is mandatory in all children. If OME is
diagnosed, then the laterality & severity of the hearing impairment will dictate management.
(audiometry is required to help determine management).
Air- bone gap: the presence of an airbone gap of at least 10db is a poor predictor of concurrent
OME. 80% of OME will have air-bone gap >10db with type B or type C2 tympanogram .
Using finding of myringotomy , 37% of ears with an air-bone gap of greater than 10db had dry tap.
When air-bone gap greater than 30db dry was less than 4%.
Carhart notch in the bone-conduction thresholds
As with any pure conductive impairment, one would expect OME to be associated with a carhart
notch in the bone conduction thresholds around 2 kHz. By definition, notch has to be 10db or
greater between .5 & 4kHz(any lesser dips could be due to test or retest error). Positive predictive
value of a carhart notch in diagnosing fluid at myringotomy is 97%.
Ideal diagnostic strategy for OME
Otoscopy should be attempted in all children not just to diagnose OME but also acute otitis media &
chronic otitis media.
In those with OME on otoscopy, tympanometry is probably confirmatory investigation. Audiometry
is help determine management.
In those in whom the tympanic membrane cannot be visualised or finding are uncertain, then
tympanometry is essential. In those with a type B or C2 tympanogram, audiometry will detect
bilateral hearing impairment of 20db or greater that merit treatment.
Management
Medical treatment
Medical treatment would potentially be of greatest benefit if it could speed the resolution of an
episode of OME.
1.Topical nasal steroids; it must be concluded that there is insufficient evidence to support
the use of topical nasal steroids at present for childhood OME.

7. 2.Systemic steroids; systemic steroids cannot be recommended at present for childhood
OME , although oral steroids are effective for longer than in the short term(2 weeks) even
when combined with antibiotics.
3.Antibiotic ; it is not recommomded that antibiotics be used for the longer term(>6weeks)
management of childhood OME.
4.Nasal decongestants; antihistamine & decongestants has no significant effect on the
resolution rate of OME.
5.Mucolytics : could not demonstrate role of OME.
6.Others approaches , autoinflation; otovent balloons indicated but problem in younger
children. Autoinflation is the strongest evidence of efficacy for older children.
Surgery
Myringotomy & aspiration : myringotomy & aspiration has not been shown to be effective in
restoring the hearing levels in children with OME.
Ventilation tubes
Ventilation tubes can be of different materials (Teflon, silicone, titanium, gold)& be coated with
silver oxide. Their shape vary but can be categorized as grommets or T tubes. In general , the larger
& stiffer the flange that goes in the middle ear, the longer it stays in situ. The longer the tube stay in
situ, it can be potentially of benefit. On the other hand, the longer the tube is in situ the greater
chance of complications , infection, granulation tissue , permanent perforation, thinning of the
tympanic membrane.
However, in adults T-tube are justified routinely, as in them OME is likely to be persistent over years
rather than months.
Surgical technique
Site : insertion of ventilation tube posteriorly is not recommomded because of the potential for
damaging the ossicular chain. No difference to extrusion rate of tube through radial or
circumferential incision. Placement antero-infereriorly compared with postero-inferiorly lengthens
the time a ventilation tube is in situ(for a shepared tube 80% versus 45% at six months & 30% versus
15% at 12 months are in situ.
To maximize the duration of potential tube function, the preferred insertion site is antero-inferior
through a circumferential or radial incision.
Associated aspiration : there is no necessity to go to greater lengths to remove all middle ear fluid
when inserting a ventilation tube.
Tropical preparations : these can be used after insertion of the tube to prevent tube blockage with
blood & infection in the postoperatively. Blockage of the tube can be prevented to some extent by
aspiration at the time of surgery. Syringing has been suggested but is only likely to be effective
before the blood dries. To control infection, antibiotic & steroids ear drops should be used & aural
toileting. Granulation tissue is similarly treated with topical preparations.

8. Hearing improvement : ventilation tubes alone will improve level by 9db at six months, 6db at 12
months, 4db at 24 months.
Adenoidectomy has an additional effect of 3-4db at six months & 1db at 12 months.
Predictive factors for benefit to hearing: younger children at day eare, those with binaural hearing
loss > 20db & persist at least 12 weeks will benefit most. No effect on age , sex or socioeconomic
group is evident.
It is concluded that short term ventilation tube give a benefit to the hearing of 4-5 db at six months
following insertion in those with documented 1) persistent bilateral OME over three months period
&2) hearing impairment of at least 20 dbHL in both ears.
It must be concluded that, in general, ventilation tubes are not indicated to aid speech & language
decelopment in children three years or younger.
Complications of ventilation tubes
At surgery
The most common complication at the time of surgery is displacement of the ventilation tube into
the middle ear. Ossicular damage will occur if the myringotomy is placed incorrectly.
Immediately post-operation
Blockage of the tube with blood can be prevented to some extend by aspiration at the time of
surgery. Syringing has been suggested but in only likely to be effective before the blood dries.
Late complications
1.Otorrhoea due to acute otitis media. Management of infection is mainly aural toilet with
topical antibiotic &steroid drops. Granulation tissue is similarly treated with topical
preparations.
2.Permanent perforation due to subsequent episode of acute otitis media.
3.Tympanosclerosis ; hyaline degeneration of the collagen tissue in the fibrous layer of the
pars tensa becomes evident otoscopically as a white patches or plaques of tympanosclerosis.
4.Pars tensa atrophy & retraction of the tympanic membrane is itself considered to be a
complication of persistent OME.
Adenoidectomy
It removes a chronic source of infection in the nasopharynx rather than because it removes tissue
that physically obstructs the Eustachian tube.
Hearing
The overall effect at six months on the hearing of adenoidectomy is 8db compared with 12 db for
ventilation tubes. Current practice is to perform adenoidectomy as an adjunct to the insertion of
ventilation tubes.

9. Upper respiratory tract infection
Adjuvant adenoidectomy improved the reported upper respiratory tract infection.
Hearing aids
Children with a cleft palate even subsequent to its surgical repair have a high incidence of OME
which is some is a constant condition. This condition is treated with hearing aids rather ventilations
tubes.

10. Upper respiratory tract infection
Adjuvant adenoidectomy improved the reported upper respiratory tract infection.
Hearing aids
Children with a cleft palate even subsequent to its surgical repair have a high incidence of OME
which is some is a constant condition. This condition is treated with hearing aids rather ventilations
tubes.