1. MOTORES ELÉCTRICOS, TIPOS Y FUNCIONAMIENTO
1.1. MOTORES DE CORRIENTE CONTINUA
1.1.2. MOTORES CC SIN ESCOBILLAS (BLDC)
Key concepts
⦁ Acute otitis media may be treated conservatively, if mild. ⦁ Do not poke the ears in otitis externa.
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answers
Clinical cases
CASE2.12– Child with earache
A1: Whatisthelikelydifferentialdiagnosis?
The most likely diagnosis is acute otitis media. Other structures may refer pain to the ear and a teething child may have pain, which can be difficult to distinguish from a middle-ear problem.
A2: Whatadditionalfeaturesinthehistorywouldyouliketoelicit?
Ask if the child has a respiratory infection. How severe is the pain? This can be gauged by asking whether the child is kept awake at night, holds his ear and wants to go to bed. Ascertain the
relationship between pain, hearing loss and discharge. Patients with pain, hearing loss and no discharge have acute otitis media. If discharge starts and the pain and hearing loss resolve, this is due to the tympanic membrane perforating reducing the pressure in the middle ear.
A3: Whatistheimportantfindingonexamination?
Examine both ears and see whether one sticks out more than the other. In acute mastoiditis, a
complication of acute otitis media, there is often a swelling behind the ear and it is pushed forwards and slightly downwards. Examine the better ear first. Children often have a pink eardrum when they have a cold. If both ears look the same, acute otitis media is unlikely. If there is pus behind the drum (diagnostic of acute otitis media), it looks yellow and bulging. This is most obvious in the posterosuperior region and this is the most common site of rupture. If the eardrum has not been examined, the diagnosis of acute otitis media is presumptive.
A4: Whatinvestigationswouldbemosthelpfulandwhy?
No investigations are required for simple acute otitis media.
A5: Whatarethetreatmentoptions?
There is much debate about the need for antibiotic chemotherapy in acute otitis media. There have been many obvious flaws in the clinical trials conducted in this area. Basically, if the child is well and has little in the way of constitutional symptoms, no treatment is required. If the child has mild discomfort, treat with analgesia, because the condition will settle in the vast majority of cases. If the child is unwell and the eardrum is bulging dramatically, treat with antibiotics such as amoxicillin at the appropriate dose for the weight and age of the child. If the child is vomiting, the first dose should be given intramuscularly. Erythromycin is a suitable alternative if the child is sensitive to penicillin. Very occasionally intracranial sepsis follows acute ear infections.
CASE2.13– Adult with earache
A1: Whatisthelikelydifferentialdiagnosis?
The most likely causes of earache in the adult are either otitis externa or referred otalgia. Young adults may have temporomandibular problems and questions about chewing and pain will help to determine if this is the cause. Elderly people may have problems with the cervical spine, which also causes a referred otalgia. Otitis externa may go from ear to ear and there is a period of irritation followed by self-inflicted trauma and secondary infection. The cycle repeats itself.
A2: Whatadditionalfeaturesinthehistorywouldyouliketoelicit?
Ascertain the relationship between pain, discharge and hearing loss. In acute otitis externa, there is typically scanty discharge, severe pain, but no hearing loss. There is usually a precipitating history of trauma, cotton buds or water exposure, swimming or syringing. Patients with acute otitis media also often complain of itching.
A3: Whatistheimportantfindingonexamination?
Examine the better ear first so that it can be compared with the one causing the problem. If there is debris, this should be removed. The diagnosis of otitis externa cannot be made until the drum has been examined and is shown to be intact. Sometimes there is a secondary otitis externa when there is a perforation, but mucus means that there is middle-ear disease. There are three common types of otitis externa: a furuncle in the hair-bearing area, and diffuse oedematous and diffuse eczematous otitis externa. Examine the temporomandibular joint and neck. Some patients poke their ears if there is pain there and set up secondary otitis externa.
A4: Whatinvestigationswouldbemosthelpfulandwhy?
No investigations are mandatory, although an ear swab may help with antibiotic sensitivity. The infecting organism is Pseudomonas aeruginosa in most cases.
A5: Whatarethetreatmentoptions?
Treatment is meticulous aural toilet. Once the debris is removed, treat with antibiotic eardrops. Tell the patient to keep the ear dry and not to poke it. If the problem does not settle easily, referral to the ENT department may be required. Patients with diabetes mellitus need careful monitoring because they may develop a severe otitis externa called malignant otitis externa. The condition may erode into the cranial cavity and can be fatal.
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OSCE Counselling case
OSCECOUNSELLINGCASE2.12– A patient wants to swim when you
have diagnosed otitis externa. What is
your advice?
No. The patient should be symptom free for 3 months before re-commencing swimming.
reVision panel
⦁ Acute otitis media is generally a self-limiting infection treated initially with conservative therapy. ⦁ If there is no resolution of acute otitis media after 48 hours, antibiotic therapy is commenced. ⦁ Mastoiditis and intracranial sepsis are rare complications of acute otitis media.
⦁ Acute otitis externa typically presents after trauma, direct or water, to the ear canal. ⦁ Treatment of acute otitis externa is with aural toilet and antibiotic drops.