Download Acute Otitis Media all 16 - HARP 2009

HARP. Case Notes
CONDITION: Acute otitis media
Alternative names:

Acute suppurative otitis media (AOM). Suppurative means containing
bacterial infection (Gelfand, 2009)

Acute purulent (suppurative) otitis media (Gelfand, 2009)
Definition:
Otitis media refers to the inflammation of the middle ear, including the
tympanic membrane. Acute otitis media has a rapid onset of symptoms. The
method of distinguishing between acute otitis media, chronic otitis media or
sub-acute otitis media is relative to the length of time the condition continues.
If the condition lasts up to three weeks then it is considered to be acute otitis
media. If it lasts for more than twelve weeks then it is known as chronic otitis
media. For intermediate durations it is known as sub-acute otitis media
(Gelfand, 2009)
There are also two grades of AOM: severe and moderate. AOM becomes
classed as severe when otalgia is severe or when the oral temperature
reaches 39C and above or both. (Bluestone, C.B, Klein, J.O., 2007). However
as children commonly suffer from AOM it may be difficult to assess their
perception of the pain and so this may be an invalid criterion.
Epidemiology:

Common condition with a high incidence but very low mortality rate
(O’Neill, 1999)

In the UK 30% children under three visit the GP with acute otitis media
each year (O’Neill, 1999)

Most common in children aged 6-18 Months (Klein, 1994), although
can occur at any age (Pavlovcinova et.al, 2008)

More common in boys (Klein, 1994)

Higher prevalence in winter (Klein, 1994)
Symptoms:

Fever

Otalgia (ear pain)

Temporary conductive hearing loss
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
Sensation of aural fullness

Young children have been reported to pull on their ears (Madell &
Flexer, 2008)
Signs:

Hyperemia, which is an enlargement of tissues with blood; especially
the tympanic membrane

Exudation may occur after several days. This is where the middle ear
fills with fluid containing white and red blood cells and mucus. This
subsequently leads to the tympanic membrane appearing red and
thickened with landmarks difficult to identify. This tends to cause
increased pain, fever and a conductive hearing loss (Gelfand, 2009)

The tympanic membrane may also bulge outwards due to the pressure
placed on it from exudation. This building pressure may cause the
tympanic membrane to rupture, giving out a discharge known as
otorrhea. In some patients it is preferable for a surgeon to perform a
procedure known as myringotomy, where a small incision of the
tympanic membrane is performed to relieve pressure and encourage
healing (Hughes & Pensak, 2007)

Chronic otitis media is often associated with a perforated eardrum
(Gelfand, 2009).
Pathophysiology:
AOM is an inflammatory condition involving the membrane of the middle ear,
including the tympanic membrane. It is caused by a bacterial infection, usually
brought on during an upper respiratory tract infection (Hughes, & Pensak,
2007 & Gelfand, 2009). Negative middle ear pressure is thought to develop as
a result of the respiratory infection and bacteria brought into the middle ear
(WHO/CIBA Foundation, 1996). The bacteria are suggested to come from the
back of the nose and throat (nasopahrynx) and travel trough the Eustachian
tube to the middle ear (Hughes & Pensak, 2007 & NHS: Acute otitis media,
2009). Hughes and Pensak (2007) suggested that there are three types of
predominant bacteria that cause acute otitis media. These are: Streptococcus
pneumonia (35%), Haemophilus influenza (23%) and Moraxella catarrhalis
(14%). However according to Gelfand (2009) Branhamella catarrhalis may
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also be a significant cause. The evidence from Gelfand (2009) and Hughes &
Pensak (2007) would suggest that the bacteria Streptococcus pneumonia and
Haemophilus influenza are the most common in causing AOM. The high
prevalence rates in young children may be due to the presence of a shorter
Eustachian tube that is also at a less vertical angle compared to adults (Fry &
Sandler,1993). This means that bacteria are able to move into the Eustachian
tube and reach the middle ear more easily than in adults. There is some
suggestion that smaller Eustachian tubes may become easily blocked,
preventing ventilation and allowing bacteria to be trapped and multiply (NHS:
Acute Otitis Media, 2009). In some cases a previous infection may weaken a
child’s immune system and make it more difficult to fight off the bacterial
infection in the middle ear (NHS: Acute Otitis Media, 2009).
Complications of otitis media:
AOM is unlikely to cause any permanent damage and 80% of cases heal with
no complications and without the need for medical intervention (Alberti, n.d.).
However complications can occur and include:

Progression to chronic otitis media (WHO/CIBA Foundation, 1996).
The condition may initially develop as an acute case of AOM but
progress to a chronic or long term infection of the middle ear.

Perforation of the eardrum can also occur.

The movement of the ossicles may also be impacted as complications
such as tympanosclerosis or ossicular chain discontinuity (Gelfand,
2009)

Facial paralysis if the infection spreads through the fallopian canal to
where the seventh cranial nerve passes through (Gelfand, 2009).

Spread of the infection to the inner ear may result in labyrinthitis
(Gelfand, 2009). Symptoms of labyrinthitis include severe vertigo,
nausea, vomiting, fatigue and uncontrollable nystagmus (NHS:
Labyrinthitis, 2009).

The infection spreading to the mastoid, known as mastoiditis. Infection
of the central nervous system can occur following mastoiditis (Gelfand,
2009).

Gelfand (2009) also suggests that a sensorineural loss can occur if the
bacteria are spread to the inner ear.
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
On a further note conductive lesions may impact on bone conduction
results, meaning that some of the results believed to be from a
sensorineural hearing loss, may in fact be due to conductive lesions.

If the hearing loss is not treated then learning may be hindered during
the temporary hearing loss. In some language development may also
suffer.
Management:

Acute Otitis Media can be treated with oral antibiotics (Gelfand, 2009 p
177) or ear drops. This is because studies and real life examples have
shown that treatment by antibiotics show a decline in suppurative
(formation of pus) complications and improved patient outcomes. Also
if it is left untreated complications may arise and these cannot be
predicted so antibiotics are given as a precautionary measure. The
antibiotics given should cover the common bacteria that cause acute
otitis media but it needs to be individualised to each patient; especially
for children taking into account of allergies and tolerance (Donaldson,
2009).Common antibiotics are amoxicillin, ampicillin and erythtomycin
(Gelfand, 2009, p 177).
HARP. Case Notes
CONDITION:Acute otitis media (AOM) in right ear
Notes: There are varying stages of AOM and patients will present with varying
symptoms and results. In order to show this four stages of AOM have been
identified. These are; a) developing AOM with patient reporting mild earache,
b) obvious case of AOM with bulging tympanic membrane, patient in obvious
pain and discomfort, c) ruptured tympanic membrane as a result of pressure
(does not occur in all cases) and d) recovering case of AOM. These stages
will be referred to throughout.
Otoscopy
Right
Left
Figure 1: ‘Stage b’ otoscopy findings
Notes: The figure above is an example of a ‘stage b’ case of AOM with visual
indications of AOM. At this stage the tympanic membrane may appear
reddened and may also bulge due to pressure from mucus and blood cells in
the middle ear space. The malleus may not be identifiable in the affected ear.
The tympanic membrane may also appear opaque (Block & Harrison, 2005).
However in other stages findings from otoscopy may not be as identifiable
and figure 2 below highlights other potential findings.
Figure 2: Otoscopy results from the right ear
1)
2)
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3)
Figure 2 shows potential findings from otoscopy at different stages of AOM. 1)
This is representative of what could be seen in a ‘stage a’ case of AOM. Here
there is come redness and bulging of the tympanic membrane yet landmarks
such as the umbo and light reflex are still identifiable. 2) This image is
representative of a ‘stage c’ case of AOM. The pressure from fluid behind the
tympanic membrane has caused it to rupture and fluid is clearly visible around
the membrane. Considerable care should be taken to minimise the risk of
cross-infection and all equipment must either be disposed of or sterilised
according to hospital procedure. 3) This image is representative of a ‘stage d’
case of AOM when the patient is recovering from the episode. Some scarring
may be evident, although many of the landmarks such as the incus and Pars
tensa are now visible.
Problems associated with testing: Patients may have otalgia, and if so careful
examination may be required. Young children may be reluctant to allow
otoscopy to be performed and caution should be taken to not cause the
patient further discomfort or anxiety. If a child has recently been crying or had
a fever then this can cause a slight reddening of the tympanic membrane and
should not be confused with a sign of AOM (Subcommittee on Management
of Acute Otitis Media, 2004)
Alternative tests:
Pneumatic Otoscopy can be carried out by creating a seal in the ear canal in
order to alternatively apply positive and negative pressures in the canal whilst
observing the tympanic membrane movement. This test can help to indicate
the presence of fluid in the middle ear by observing reduced tympanic
membrane movement and therefore can be useful in indicating the presence
HARP. Case Notes
of AOM. (Stool & Berg, 1994, pp30)
Tuning forks
Figure 3: ‘Stage a, b and c’ tuning fork results
Right
Left
Weber:
Right ear
Rinne:
Negative
Positive Rinne
Rinne
Notes: Sound lateralisation to the right ear during the Weber test indicates a
conductive loss and this supports the negative Rinne result for that ear, which
also indicates a conductive loss on the right. These results are likely to be the
case for stages a, b and c. In stage d the clearing of fluid from the middle ear
and the healing of any perforation means that the patient should have
regained their ‘normal’ thresholds and so have negative Rinne results for both
ears and the Weber test should be loudest centrally if they have symmetrical
hearing.
Reliability of test: As young children are typically affected by AOM they may
be unable to distinguish which ear sound lateralises to and by which method
the sound is loudest in, so both tests may not give reliable results in a
younger age group. There are also general limitations of these tests, including
the unreliability of the tone as this varies depending on the force used
(Gelfand, 2009). Gelfand (1977, cited in Gelfand, 2009) also found that the
Rinne test may only correctly diagnose a conductive loss if the air-bone gap is
up to 60 dB when using a 512 Hz tuning fork. Therefore these tests have
variable results and may explain why the British Society of Audiology (BSA)
states that they should only be used to “establish the probable presence or
absence of a significant conductive… loss”.
Alternative tests: Objective tests that do not require a response may be more
useful in children in order to determine the presence of AOM. Such tests
include Otoacoustic emissions, which can determine if there is a conductive
loss.
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Pure tone audiometry and uncomfortable loudness levels
Figure 4: ‘Stage b’ audiogram
Notes: Masking was required at 500, 1000, 2000 and 4000 Hz due to the
presence of a 30dB or greater air-bone-gap in figure 3.
The audiorgram shape may appear to be flat or ‘tented’, with a
peak in the mid-frequencies (Gelfand, 2009), with a mild to moderate
conductive loss (Alper et. Al, 2004). Some patients may have a sensorineural
component to their loss (although not indicated in the audiogram above) and
this is thought to be caused by the transfer of toxins to the inner ear (Gelfand,
2009). Figure 5, below, highlights the varying audiogram shapes and levels
which may be seen at the different stages of AOM.
Figure 5: Right ear audiogram results for different stages of AOM
1)
2)
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3)
Figure 5 highlights the different stages of AOM. 1) This is an adapted example
of a ‘stage a’ or developing case of AOM. In this case there is a clear peak at
1000 Hz and there is an air bone gap, although it is smaller than that seen in
figure 4 above. Masking was still required at 500, 2000 and 4000 Hz. 2) This
is an adapted case of a ‘stage d’ or recovering case of AOM. Here the air
bone gap is no longer present and audiometric thresholds have been restored
to within normal thresholds. 3) This is an adapted example of a sensorineural
loss related to AOM (Gelfand, 2009). Here the spread of toxins to the cochlea
has led to a moderate sensorineual hearing loss (BSA Guidelines, 2004).
Problems associated with testing: As this test requires patient co-operation
and understanding it is therefore not suitable for younger children.
Alternative tests: If a patient is too young to perform Pure Tone Audiometry
(PTA) then tympanometry can be used to ascertain the condition of the
tympanic membrane. However tympanometry should not be carried out when
there is an active infection. For children over 2 and a half years adaptations of
PTA such as the McCormick toy test or conditioned play audiometry may be
more suitable to assess their hearing. The McCormick toy test enables an
estimation of hearing threshold in 6 dB steps using seven ‘pairs’ of toys with
similar vowel sounds and different consonants. An automated voice names
the toy and the child should then point to the toy they heard. Care must be
taken beforehand that the child knows the name of each toy to prevent
confusion and invalid results. Conditioned play audiometry sees the child
conditioned to hold a toy at their ear and drop it into a bucket when they hear
HARP. Case Notes
a sound (Stach & Ramachandran, 2008). The sounds become progressively
quieter until an estimation of their threshold is found. The choice of PTA in
young children varies for each child and is dependent on their age and
cognitive level.
Tympanometry
Notes:
Tympanometry should not be carried out on patients with a current ear
infection, such as AOM. This also includes patients who report ear tenderness
and pain during history taking. If tympanometry was carried out in a patient
with a developing case of AOM, who reports little or no pain in clinic (‘stage
a’), then a flat tympanometry shape is likely to be seen. This is indicated in
figure 6 below.
Figure 6: A ‘stage a’ tympanogram
The typmanometry results show that the right ear has a flat trace. The ear
canal volume is within the normal range of 0.5-1ml for children and so the
results indicate that there is fluid behind the right tympanic membrane. The
results from the left ear indicate a normal tympanogram shape, classed as a
type ‘A’ tympanogram (Jerger, 1970, cited in Katz et. Al, 2009).
Notes on testing method: A screening mode was used in order
minimise the time that the young patient spent with the probe in their ear. This
is a potential problem when dealing with paediatric patients but the faster
mode does slightly help to overcome this.
HARP. Case Notes
Acoustic reflexes
Notes:
Acoustic reflexes should also not be performed in patients with current ear
infections, including AOM. If acoustic reflex testing were to be carried out on a
‘stage a’ patient, then figure 7 below highlights some possible findings:
Figure 7: Possible acoustic reflex thresholds in a ‘stage a’ patient
Threshold
Right
Probe ear
contralateral
ipsilateral
85 dB
X
80
X
Left
ipsilateral
contralateral
1000 Hz
90 dB
X
2000 Hz
90
X
Results were obtained for the left ipsilateral reflex and the contralateral right
reflex at 1000 and 2000 Hz. Both of these thresholds were within the normal
threshold range of 75-90 dB Hearing Level (HL) for pure tone sounds.
However no results were obtained for the right ipsilateral and left contralateral
reflex at 1000 and 2000 Hz. The stimulus ear principle suggests that a
conductive loss in the stimulus ear will raise the acoustic reflex by the level of
the air bone gap (Katz et. al, 2009). In this case as the air bone gap is 10-15
dB and acoustic reflex thresholds were unable to be reached as testing was
stopped at 100 dB to limit the level of noise exposure. Testing was only
carried out at 1000 and 2000 Hz as the results were similar and no further
testing was necessary.
Otoacoustic emissions
Notes: It would not be suitable to perform Otoacoustic emissions (OAE’s)
testing in ‘stage b and d’ where the patient may be in pain and the risk of
infecting the probe and having to decontaminate the equipment is high.
Performing OAE’s in these patients would also not inform the tester of any
new or additional information that that they have already gained from
otoscopy and PTA. However they may be performed in ‘stage a or d’ cases as
shown in figure 8, below.
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Figure 8: Otoacoustic emissions results form a ‘stage a’ case of AOM
Definitely present
Possibly present
Right
Left
Absent
Yes
Yes
Transient Evoked Otoacoustic emissions (TEOAE’s) testing was carried out
between 500 Hz to 4 kHz. ILO 292 measurement system was used. A
standard non-linear stimulus paradigm was used at a rate of 50 clicks per
second in order to minimise the risk of stimulus artefacts. Definition of a
present TEOAE was based on the reproducibility percentage with values
above considered to be a possible TEOAE, above 75% a definite TEOAE and
below 50% the procedure was repeated once and then deemed to be too
noisy to obtain an accurate measurement. It was also based on the dispersion
of the TEOAE waveform with high frequency components appearing first,
followed by low frequency components. The overall shape of the OAE was
also taken into account. This test is particularly useful in children, as it does
not require patient response (OAE Guide, 2009)
The presence of a definite TEOEA in the left ear indicates that outer hair cells
present in the patients cochlear are actively amplifying sound. From this we
can invoke that this patient has relatively ‘normal’ hearing. In babies and
children the amplitude of the OAE may be greater than that seen in the adult
population. However in the right ear there is an absent OAE. Using evidence
from history taking, otoscopy and PTA it is assessed that the reason for the
absent OAE is due to the presence of a conductive hearing loss, as the result
of the patients AOM. OAE’S are usually absent if there is an air bone gap of
15 dB or greater (Owens et. al, 1992; Prieve, 1992; Kemp et. al, 1990;
Cullington et. al, 1998, all cited in Hall, 2000). In AOM this absent OAE is
because the build up of pus and fluid reduces the level of the click stimulus
reaching the cochlea and also greatly reduces the level of the OAE returning
back to the External auditory meatus (ear canal). There may well be a fully
HARP. Case Notes
functioning cochlea and outer hair cells but the conductive loss has reduced
the OAE to below the noise floor and so an OAE is not picked up.
Problems associated with testing: Physiological noise from the patient may
impact on test results. The test environment must also be acoustically silent
(OAE’s for Otolaryngologists, 2009).
General comments:
Then diagnosis of AOM should only be made following a battery of
audiological tests, such as those indicated above. Differential diagnosis
should be considered with conditions that give similar results. Medical
concerns should be referred to ENT.
HARP. Case Notes
Sources of evidence:
A guide to: Otoacoustic Emissions (OAE’s) for Otolaryngologists, 2009, Maico
Diagnostics, USA, Retrieved 28th April 2009 from: http://www.maicodiagnostics.com/eprise/main/_downloads/us_en/Documentation/OAEOtolaryn
gologistsbooklet.pdf
Alberti, P.W., n.d., The Pathophysiology of the Ear, World Health Organisation
(WHO) occupational health report, Retrieved 27th April 2010 from:
http://www.who.int/occupational_health/publications/noise3.pdf
Alper, C.M., Bluestone, C.D., Johar, J.E., Mandel E.M. & Casselbrant, M.L.,
2004, Advanced therapy in Otitis Media, Illustrated edn, BC Decker
Publishers, USA, pp 419-420
Block, S & Harrison, C.J., 2006, Diagnosis and Management of Acute Otitis
Media, 3rd edn, Professional Communications Incorporated, USA, pp 11-12
Bluestone C.D., Klein J.O., 2007, Otitis media in infants and children, 4th Ed.,
BC Decker: Hamilton Ontario, Canada, pg 271
BSA Recommended procedure, 2004, Pure tone air and bone conduction
threshold audiometry with an without masking and determination of
uncomfortable loudness levels, pg 17
Donaldson, J.D., 2009, Middle Ear, Acute Otitis Media, Medical Treatment,
emedicine, Retrieved 28th February 2010 from:
http://emedicine.medscape.com/article/859316-overview
Fry, J, Sandler, G, 1993, Common diseases: Their nature, prevalence and
care, Radcliffe Publishing, Oxford, UK.
Gelfand, S.A, 2009, Essentials of Audiology, 3rd Ed., Thieme Medical
Publishers Inc., NY, USA, pp 174-176
Gelfand, S.A., 2009, Essentials of Audiology, Thieme Medical Publishers,
New York, USA
HARP. Case Notes
Hall, J.W., 2000, Handbook of Otoacoustic emissions, Thomas Learning,
Singular Publishing Group, California, USA, pg 228
Hughes, G.B, Pensak, M.L, 2007, Clinical Otology, Thieme Medical
Publishing group, USA.
Klein, J.O., 1994, Otitis Media, Clinical Infectious Diseases, 19(5), pp. 823832, The University of Chicago Press.
Madell, J.R., Flexer, C, 2008, Pediatric Audiology: Diagnosis, Technology and
Management, Thieme Medical Publishers, New York, USA, pp 77-79
NHS Choices, Otitis Media, Retrieved 28th February 2010 from:
http://www.nhs.uk/Conditions/Otitis-media/Pages/Causes.aspx
NHS Choices: Labyrinthitis, Retrieved 25th April 2010 from:
http://www.nhs.uk/Conditions/Labyrinthitis/Pages/Symptoms.aspx
O'Neill, P, 1999, Clinical review: Acute otitis media, British Medical Journal,
319: pp 833-835.
Otitis media, 2002, NIDCD (National Institute on Deafness and other
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Pavlovcinova, G, Jakubikova, J, Hromadkova, P, Mohammed, E, 2008,
Severe Acute Otitis Media in children, Bratislava Medical Journal, 109 (5), pp
204-209
Shanks, J & Shohet, J, 2009 ‘Tympanometry in clinical practice’ in Katz, J,
Medwetsky, L, Burkard, R & Hood, L, (eds), Handbook of Clinical Audiology,
Lippincott Williams & Wilkins, USA pp 159-185
HARP. Case Notes
Stach, B.A., Ramachandran, V.S., 2008, ‘Hearing Disorders in Children’, in
J.R., Madell & C. Flexer, (eds), Pediatric Audiology: Diagnosis, Technology
and Management, Thieme Medical Publishers, New York, USA
Stool S.E., Berg A.O.,1994, Otitis Media with Effusion in Young Children:
Clinical Practice Guideline, Diane Pub Co, Darby, PA, USA
Subcommittee On Management of Acute Otitis Media, Diagnosis and
Management of Acute Otitis Media, Pediatrics; 113, pp 1451- 1465
WHO/CIBA Foundation Workshop, 1996, Prevention of hearing impairment
from Chronic Otitis Media, London, UK, Retrieved 27th April 2010 from:
http://www.who.int/pbd/deafness/en/chronic_otitis_media.pdf, pp 14-16