ENT - Head and neck Flashcards
What are the 3 divisions of the pharynx?
The pharynx is the upper part of the combined air and food passages - aero-digestive tract. It is divided into 3 parts - the nasopharynx, the oropharynx and the hypopharynx or laryngopharynx.
What are the boundaries of the nasopharynx?
The nasopharynx is between the base of the skull and the level of the hard palate. It contains the adenoids (in children) and the Eustachian tube.
Where is the oropharynx?
The oropharynx runs from the level of the hard palate down to the level of the vallecula - this is the junction between the base of the tongue and the epiglottis. The tonsils, base of the tongue, and the soft palate are all found in the oropharynx.
Where is the hypopharynx?
The hypopharynx extends between the level of the vallecula to the cricopharynx which is a muscular sphincter at the upper end of the oesophagus.
What are the 3 stages of swallowing?
Swallowing is a complex process requiring coordination of the muscles of the oral cavity, pharynx and larynx. Loss of function of any of these stages can cause potential aspiration and LRTI.
The 3 stages are:
1) oral phase
2) pharyngeal phase
3) oesophageal phase - food bolus passes through the oesophagus and into the stomach
What happens in the oral and pharyngeal phases of swallowing?
Oral phase - Mastication and partial digestion by salivary glands produces a food bolus which is shaped by the tongue. The tongue also pushes the bolus into the oropharynx.
Pharyngeal phase - muscles around the larynx close and push the food bolus into the oesophagus. These muscles are known as the pharyngeal constrictors. During this phase the larynx is elevated to protect the airway and lower respiratory tract.
How is the pharynx examined?
It is difficult to visualise the nasopharynx and hypopharynx without the use of a flexible endoscope. But the oropharynx can be easily examined using a light source and a tongue depressor.
What are the adenoids? Are they normally visible on examination?
The adenoids are a collection of lymphoid tissue. They are part of a circle of lymphoid tissue known as Waldeyer’s ring that surrounds the entrance to the pharynx and respiratory tract. The other parts of the ring include the lingual tonsils on the base of the tongue and the pharyngeal tonsils.
Remember that the pharynx is divided into 3 parts - naso, oro and hypopharynx. The adenoids are located in the nasopharynx. They are not usually visible on examination of the oropharynx by direct vision because they lie behind the soft palate near the posterior openings (choanae) of the nose.
Symptoms of adenoid hypertrophy
- nasal obstruction/ rhinorrhoea
- mouth breathing/ hyponasal speech
- secretory otitis media (glue ear)/ acute otitis media
- snoring/ obstructive sleep apnoea
Why is adenoid hypertrophy associated with OME?
OME is otitis media with effusion or glue ear and is defined as symptoms caused by fluid collection in the middle ear for greater than 3 months. Gross enlargement of the adenoids causes obstruction of the Eustachian tube and pressure changes in the middle ear which can result in OME. If this occurs with a spread of infection to the middle ear along the Eustachian tube then an acute middle ear infection usually arises.
Do adults have adenoidal tissue?
Adenoids reach maximal size between the ages of 5-7 years and then regress. Adults have very little (if any adenoidal tissue) and the presence of nasopharyngeal masses in adults should be investigated further to exclude other pathology.
What are the main indications for adenoidectomy?
- airway obstruction caused by enlarged adenoids (often combined with tonsillectomy in obstructive sleep apnoea)
- OME - as an adjuvent procedure with grommet insertion in recurrent cases of glue ear
Contraindications for adenoidectomy
- bleeding disorders
- palatal abnormalities - palate must be palpated prior to the procedure to assess for undiagnosed submucal clefts
- recent URTI
Complications of adenoidectomy
- bleeding
- velopharyngeal insufficiency (i.e. nasal regurgitation). This is rare and usually short lived
- hypernasality - can be a significant problem if the patient has an undiagnosed palatal deformity. Air escapes through the nose during sleep
What patients get nasopharyngeal cancer?
Not all nasal obstruction in children is caused by adenoids. There are other causes such as nasopharyngeal cancer. This is rare in western populations and is more common in individuals who live in certain provinces of China.
EBV has been implicated in the aetiology.
All nasopharyngeal masses in adults as well as unilateral glue ear must be investigated for nasopharyngeal cancer.
Pharyngeal infection
Viruses normally infect the pharynx and acute pharyngitis is part of many upper respiratory tract infections including the common cold. Infection of the pharynx can cause enlargement of the tonsils - acute tonsilitis. This is one of the more common infections of children and young adults and a typical attack will last 3 to 7 days.
What are the main organisms implicated in acute tonsillitis?
- viruses
- pyogenic bacteria - e.g. haemophilus, pneumococcus, haemolytic strep
What are the main clinical features of acute tonsillitis?
- sore throat
- odynophagia (painful swallowing)
- fever
- malaise
- enlarged cervical lymph nodes
- enlarged red tonsils
O/E the tonsils are red, swollen and coated with pus. An important differential to think about is infectious mononucleosis (glandular fever), which has a similar appearance but with a more definite membrane over the tonsils and usually splenomegaly
What is the treatment for acute tonsillitis?
Treatment is controversial. Very enlarged tonsils that contribute to obstructive sleep apnoea are removed surgically together with the adenoids.
Most cases of tonsil infection (like most URTIs) are viral and will not respond to antibiotics. An acute sore throat is probably best treated with good analgesia and fluids. If an ongoing bacterial infection is suspected then a short course of antibiotics is sensible. Pen V is the first line choice.
Avoid amoxicillin or ampicillin if glandular fever is suspected because they cause the patient to develop a florid rash.
How should tonsillitis be investigated?
If infectious mononucleosis is suspected then an FBC and glandular fever screen (Paul-Bunnell or monospot test) can be helpful. A finding of raised monocyte count on white cell differential usually indicates glandular fever even if the glandular fever screen is normal.
FBC is also useful if there is suspicion of agranulocytosis - this can be a presentation of leukaemia.
Diptheria is very rare but in parts of the world where it is endemic a smear and culture is useful.
What are the outcomes of acute tonsillitis?
Most cases of tonsillitis will resolve spontaneously. However there are a few important complications to bear in mind:
1) Rheumatic fever - follows an attack of acute tonsilittis by streptococci leading to endocarditis
2) Glomerulonephritis - acute renal failure following streptococcal infection
3) Septicaemia - very rare, mostly immunocompromised patients
There are also some complications of local spread:
- Quinsy
- retropharyngeal abscess
- parapharyngeal abscess
What is Quinsy?
This is a collection of pus in the peri-tonsillar space just lateral to the tonsil. Quinsy occurs mainly in young adults and causes severe pain and dysphagia.
The patient needs to be admitted to hospital and the abscess drained surgically. It can then be treated with antibiotics.
Where does a retropharyngeal abscess occur?
This occurs most commonly in very young children - usually under 2. Pus collects in a lymph node between the vertebral column and the pharynx. It can quickly obstruct a childs airway and treatment is by surgical drainage under anaesthesia.
Parapharyngeal abscess
This is a collection of pus in the parapharyngeal space which is formed by the deep cervical fascia in the side of the neck. It can lead to mediastinitis and venous thrombosis.
What are the tonsils?
The tonsils are a collection of lymphoid tissue at the entrance to the pharynx on either side of the uvula (i.e. the palatine tonsils). There are also lingual tonsils at the base of the tongue. All of these, as well as the adenoids, are part of Waldeyer’s ring which is a collection of lymphoid tissue that forms the first line of defence against infection.
The tonsils are lined with squamous epithelium that forms crypts that extend well into the body of the tonsils where pus and debris collect.
What diseases can affect the tonsils?
Infection - mostly viral, self limiting; sometimes bacterial (e.g. streptococcal), more severe and lasts longer
Obstruction - large tonsils contribute to airway obstruction, young children
Neoplasia - tonsil can be a site of malignant disease - squamous cell carcinoma of the oropharynx in adults and very rarely lymphoma or rhabdomyosarcoma in children where the presentation may be unilateral tonsils
Bleeding - haemorrhagic tonsillitis
Indications for performing tonsillectomy - what do the SIGN guidelines recommend?
- suspected malignancy
- bleeding
- oropharyngeal obstruction (OSA)
- recurrent tonsilitis (including complications), main reason
The SIGN guidelines recommend indications for tonsillectomy for recurrent sore throats in both children and adults are as follow:
- sore throats due to acute tonsillitis
- episodes bad enough to require time off work or school
- 7 or more episodes in 1 year, 5 or more in 2 consecutive years or 3 or more in 3 consecutive years
Is tonsillectomy a day-case procedure?
Tonsillectomy is painful but most cases are performed as a day case operation (i.e. the patient goes home the same day). The exception to this is children undergoing tonsillectomy for OSA. They should stay overnight for sats monitoring.
What is the main post op complication in tonsillectomy?
Bleeding.
It is also normal to have a granular, sloughed appearance of the tonsillar fossa after the operation. This is not an indication of infection and therefore the patient does not need antibiotics.
How can the larynx and trachea be injured?
1) penetrating wounds - e.g. gunshot or cut throat injuries
2) blunt trauma, especially RTC
3) inhaled flames or hot vapours
4) swallowed corrosive poisons
5) endotracheal tubes and inflatable cuffs
What are the key features of laryngeal and tracheal injury management?
Laryngeal and tracheal injury should always be suspected when there is damage to the neck. Crichotracheal separation may not be immediately obvious but can lead to asphyxia.
Fractures of the larynx will produce hoarseness and stridor and tracheostomy may be urgently required.
In the cases of cut throat, it may be possible to intubate through the wound prior to formal tracheostomy and laryngeal repair. The 2 priorities of treatment are:
1) to protect the airway by intubation or tracheostomy
2) to restore laryngeal function by careful repair of the injury
What commonly causes acute laryngitis in adults?
Acute laryngitis is more common in winter months and it usually caused by coryza (common cold) or influenza. Vocal over use, smoking and alcohol predipose to laryngitis.
