ENT viva questions and answers: 45 spoken answers for the MBBS final-year practical, with examiner reasoning

What are the landmarks of a normal tympanic membrane on otoscopy?

A normal tympanic membrane is pearly grey and shows the handle and lateral process of the malleus, the umbo at the tip of the handle, the cone of light in the anteroinferior quadrant, and the pars flaccida above the lateral process with the pars tensa below. I describe any perforation by quadrant and by whether it is central, marginal or attic, because that decides whether the disease is safe or unsafe.

The follow-up is always 'why is the cone of light anteroinferior?' Answer: because of the concavity and the inward slant of the membrane in that quadrant.

Differentiate tubotympanic and atticoantral CSOM.

Tubotympanic or safe-type CSOM involves the anteroinferior middle ear, has a central perforation, profuse mucoid odourless discharge and rarely causes complications. Atticoantral or unsafe-type involves the attic and antrum, has an attic or marginal perforation with cholesteatoma or granulations, scanty foul-smelling discharge, and carries a risk of bone erosion and intracranial complications. The first is treated with aural toilet, topical antibiotics and later tympanoplasty; the second needs mastoid surgery.

Examiners want the word 'cholesteatoma' and the phrase 'bone-eroding'. That is what makes it unsafe.

What is a cholesteatoma and why does it erode bone?

A cholesteatoma is a sac of keratinising stratified squamous epithelium in the middle ear cleft, which is skin in the wrong place; it is neither a tumour nor does it contain cholesterol. It erodes bone by pressure from the expanding keratin mass and by enzymes such as collagenases released from the matrix and the surrounding granulation tissue. Because it keeps growing, it is removed surgically by mastoidectomy; medicine alone cannot cure it.

Be ready for 'types': congenital, primary acquired (retraction pocket) and secondary acquired (through a perforation).

List the complications of CSOM.

I divide them into intratemporal and intracranial. Intratemporal complications are mastoiditis, petrositis, facial nerve palsy and labyrinthitis. Intracranial complications are extradural abscess, subdural abscess, meningitis, brain abscess, lateral sinus thrombophlebitis and otitic hydrocephalus. The commonest intracranial complication is meningitis, and the commonest site of an otogenic brain abscess is the temporal lobe, followed by the cerebellum.

The trap: 'which complication is commonest?' Students say brain abscess. Say meningitis, then name the lobe for the abscess.

How do you interpret Rinne's and Weber's tests?

Rinne's test compares air and bone conduction in the same ear with a 512 Hz fork. Rinne positive, where air conduction is better than bone, is seen in a normal ear and in sensorineural loss. Rinne negative, where bone conduction is better, means a conductive loss with an air-bone gap of roughly 15 to 20 decibels or more. Weber's test placed on the forehead lateralises to the worse ear in conductive loss and to the better ear in sensorineural loss, so the two tests together tell me the type and the side.

Then: 'What is a false negative Rinne?' In severe unilateral sensorineural loss the bone conduction is heard by the opposite cochlea, mimicking a conductive loss. Masking with a Barany noise box resolves it.

Describe the types of tympanogram.

Type A is a normal peak at atmospheric pressure. Type As is a shallow peak, seen in otosclerosis or ossicular fixation, and type Ad is a tall peak, seen in ossicular discontinuity or a flaccid membrane. Type B is a flat curve, seen in middle ear fluid or a perforation, and type C is a peak shifted to negative pressure, seen in eustachian tube dysfunction. I always check ear canal volume with a type B curve, because a large volume means a perforation rather than fluid.

The last sentence is the clinical reasoning the examiner is listening for.

What is otosclerosis and how is it treated?

Otosclerosis is a disease of the bony labyrinth in which spongy bone replaces the normal enchondral bone, most often fixing the stapes footplate at the oval window and causing a progressive conductive hearing loss in a young adult, often worse in pregnancy. Typical findings are a normal tympanic membrane, a negative Rinne, paracusis Willisii, and a Carhart's notch at 2 kHz in bone conduction on audiometry. Treatment is stapedotomy or stapedectomy with a prosthesis; a hearing aid is the alternative for patients who decline surgery.

Schwartze sign, a reddish flamingo-pink blush on the promontory, is the examiner's favourite follow-up.

What is Meniere's disease and what is the triad?

Meniere's disease is endolymphatic hydrops, a distension of the endolymphatic compartment of the inner ear of unknown cause. The classic triad is episodic rotatory vertigo lasting minutes to hours, fluctuating low-frequency sensorineural hearing loss and tinnitus, with aural fullness often described as the fourth symptom. Management is salt restriction and vestibular sedatives in the acute attack, diuretics and betahistine between attacks, and intratympanic gentamicin or surgery for intractable cases.

Say 'low-frequency' sensorineural loss. Early Meniere's affects the low frequencies, unlike presbycusis.

How do you diagnose and treat benign paroxysmal positional vertigo?

BPPV is brief positional vertigo caused by displaced otoconia, most often in the posterior semicircular canal. I diagnose it with the Dix-Hallpike manoeuvre, which produces a latent, fatigable, torsional upbeating nystagmus with vertigo when the affected ear is turned down. Treatment is a repositioning manoeuvre, usually the Epley manoeuvre, which moves the particles back into the utricle; drugs have little role beyond short-term symptom relief.

Examiner trap: 'Is hearing affected?' No. BPPV has no hearing loss; if there is, think again.

A child has fever, earache and a bulging red drum. What is your diagnosis and management?

This is acute suppurative otitis media in the stage of suppuration, usually following an upper respiratory infection with Streptococcus pneumoniae, Haemophilus influenzae or Moraxella as the common organisms. I would start a course of oral amoxicillin, give an analgesic and antipyretic, and a decongestant nasal drop for eustachian tube function, and review in 48 to 72 hours. If the drum is bulging with severe pain or there is no improvement, I would consider myringotomy to drain the middle ear and prevent a ragged spontaneous perforation.

If asked why myringotomy rather than waiting: a surgical incision heals cleanly; a spontaneous rupture may leave a permanent perforation.

What is glue ear and when do you insert a grommet?

Glue ear, or otitis media with effusion, is a non-purulent, thick fluid in the middle ear behind an intact drum, usually in a child with adenoid hypertrophy and eustachian tube dysfunction, presenting as hearing loss and poor school performance. The drum looks dull or retracted and tympanometry is type B. I treat medically for about three months; if the effusion and hearing loss persist, I do a myringotomy with a ventilation tube, often with adenoidectomy. In an adult with a unilateral effusion I must examine the nasopharynx to exclude a carcinoma.

The adult unilateral effusion sentence is the one that separates a pass from a good pass.

How do you differentiate an upper from a lower motor neuron facial palsy, and what is Bell's palsy?

In a lower motor neuron palsy the whole half of the face is weak, including the forehead, so the patient cannot wrinkle the brow or close the eye on that side. In an upper motor neuron lesion the forehead is spared because the upper face has bilateral cortical representation. Bell's palsy is an acute idiopathic lower motor neuron facial palsy, probably viral, treated with oral steroids started early, eye protection with lubricants and taping, and physiotherapy; most patients recover fully. I grade recovery with the House-Brackmann scale.

Follow-up: 'name the branches of the facial nerve in the temporal bone' — greater superficial petrosal, nerve to stapedius and chorda tympani.

What is an acoustic neuroma and how does it present?

An acoustic neuroma is a benign vestibular schwannoma, most often arising from the superior vestibular division of the eighth nerve in the internal auditory canal, growing into the cerebellopontine angle. It presents with a slowly progressive unilateral sensorineural hearing loss with disproportionately poor speech discrimination, tinnitus and imbalance, and later with trigeminal numbness, facial weakness and cerebellar signs. The investigation of choice is gadolinium-enhanced MRI, and any unilateral asymmetric sensorineural loss must be imaged to exclude it.

The examiner wants 'unilateral asymmetric SNHL must be imaged'. Say it unprompted.

What is malignant otitis externa?

Malignant or necrotising otitis externa is a severe Pseudomonas aeruginosa infection of the external canal in an elderly diabetic or immunocompromised patient that spreads to the skull base as an osteomyelitis. The pointer is severe, out-of-proportion otalgia with granulation tissue at the bony-cartilaginous junction of the canal, and later cranial nerve palsies, most often the facial nerve. It is not a malignancy; treatment is prolonged anti-pseudomonal antibiotics, strict glycaemic control and local debridement.

If asked what imaging, say CT of the temporal bone and skull base, with a technetium bone scan or MRI for extent.

How do you remove a live insect, and a seed, from the ear canal?

For a live insect I first kill or immobilise it by instilling warm oil or lignocaine drops, then remove it by syringing or with forceps under vision, because a moving insect damages the drum and causes great pain. For a vegetable foreign body such as a seed I avoid syringing, because water makes the seed swell and impact; I remove it dry with a Jobson Horne probe or a hook passed beyond it. If the child is uncooperative, I do it under general anaesthesia rather than risk a canal or drum injury.

The trap is syringing a seed. Make sure the examiner hears you rule it out.

Name the types of mastoidectomy.

Cortical or simple mastoidectomy removes the mastoid air cells without disturbing the posterior canal wall and is done for acute coalescent mastoiditis. Modified radical mastoidectomy removes the disease with the posterior canal wall, creating a common cavity, while preserving the ossicles and middle ear function where possible; it is the standard operation for cholesteatoma. Radical mastoidectomy also removes the tympanic membrane and ossicles except the stapes and closes the eustachian tube, and is reserved for extensive disease where hearing cannot be preserved.

Be ready for 'what is a canal wall up versus canal wall down procedure?' The same distinction said in modern language.

What is Little's area and why is it the commonest site of epistaxis?

Little's area is the anteroinferior part of the nasal septum where four arteries anastomose to form Kiesselbach's plexus: the anterior ethmoidal, the sphenopalatine, the greater palatine and the septal branch of the superior labial artery. It is the commonest site of epistaxis, especially in children and young adults, because the mucosa is thin, exposed to drying air and finger trauma, and sits over a rich anastomosis. Posterior bleeds in older hypertensive patients tend to come from Woodruff's plexus or the sphenopalatine branches.

A very common follow-up: 'Which of these is a branch of the internal carotid?' The anterior ethmoidal, via the ophthalmic artery.

How do you manage a patient who walks in with active epistaxis?

I would sit the patient up leaning forward, pinch the soft part of the nose for ten minutes by the clock, which is Trotter's method, and check pulse and blood pressure while an IV line is placed if the bleed is heavy. After clearing clots I look for the bleeding point with a nasal speculum; an anterior point is cauterised with silver nitrate or packed with a ribbon gauze anterior pack. A posterior bleed needs a posterior pack or a balloon, admission and antibiotics, and if it continues, endoscopic sphenopalatine artery ligation. Later I investigate the cause: hypertension, anticoagulants, a bleeding disorder or a mass.

Examiners penalise students who start with packing. Start with first aid and resuscitation, then local measures.

What is the difference between septoplasty and submucous resection?

Submucous resection, or SMR, removes the deviated cartilage and bone of the septum after elevating mucoperichondrial flaps on both sides, leaving only a dorsal and caudal strut; it is avoided before about 17 years because it can disturb growth of the nose. Septoplasty is a conservative operation that corrects the deviation by repositioning and removing only the deformed segment, preserving most of the cartilage, so it can be done at a younger age and carries less risk of a septal perforation or saddle nose. Today septoplasty is the standard operation.

Name the instruments if asked: Freer's elevator, Ballenger's swivel knife for SMR, Killian's long-bladed speculum.

Compare an antrochoanal polyp with ethmoidal polyps.

An antrochoanal or Killian's polyp is single and unilateral, arises from the maxillary antrum, grows backwards through the ostium to the choana, occurs in children and young adults and is usually non-allergic; it rarely recurs after complete removal, which is now done endoscopically. Ethmoidal polyps are multiple, bilateral, arise from the ethmoid labyrinth, grow forwards into the nose, occur in adults with allergy, asthma or aspirin sensitivity, and recur often, so they need endoscopic sinus surgery plus long-term intranasal steroids.

Samter's triad: asthma, aspirin sensitivity and nasal polyps. Nasal polyps in a child should make you think of cystic fibrosis.

Where do the paranasal sinuses drain?

The middle meatus receives the frontal sinus, the anterior ethmoidal cells and the maxillary sinus, which is why it is the key area in functional endoscopic sinus surgery, the osteomeatal complex. The superior meatus receives the posterior ethmoidal cells, and the sphenoid sinus drains into the sphenoethmoidal recess above the superior turbinate. The inferior meatus has no sinus opening; it receives the nasolacrimal duct.

'Why is the maxillary sinus most often infected?' Its ostium is high on the medial wall, so it does not drain by gravity.

What is the Holman-Miller sign and what diagnosis does it suggest?

The Holman-Miller or antral sign is the anterior bowing of the posterior wall of the maxillary antrum on a lateral skull film or CT, caused by a mass in the pterygopalatine fossa. It is classical of juvenile nasopharyngeal angiofibroma, a benign but highly vascular tumour of adolescent boys presenting with recurrent profuse epistaxis and progressive nasal obstruction. I would never biopsy it in the clinic because of the bleeding risk; diagnosis is by contrast CT and angiography, and treatment is surgical excision after embolisation.

The examiner wants to hear 'do not biopsy' and 'adolescent male'.

What is atrophic rhinitis?

Atrophic rhinitis is a chronic disease in which the nasal mucosa and underlying turbinate bone atrophy, giving a roomy nasal cavity filled with foul-smelling greenish crusts; the patient does not notice the smell because of merciful anosmia. Primary atrophic rhinitis is commoner in young women and is associated with Klebsiella ozaenae; secondary follows excessive surgery, syphilis or radiation. Treatment is alkaline nasal douching, glucose-glycerine drops to inhibit bacteria, and surgery such as Young's operation to close the nostrils temporarily and allow the mucosa to recover.

Follow-up: components of the alkaline douche solution. Sodium bicarbonate, sodium biborate and sodium chloride.

What is rhinosporidiosis?

Rhinosporidiosis is a chronic granulomatous infection caused by Rhinosporidium seeberi, seen in people who bathe in stagnant ponds, with Tamil Nadu, Kerala and Karnataka being endemic areas. It presents as a pink, friable, strawberry-like polypoidal mass with white spots representing sporangia, which bleeds on touch and often grows from the septum or the inferior turbinate. Treatment is wide excision with electrocautery of the base to reduce recurrence, and dapsone is given as an adjunct.

Histology shows large sporangia with endospores. The 'strawberry' description is the spotter answer.

How do you confirm CSF rhinorrhoea?

A clear watery unilateral discharge that increases on bending forward or straining, which is the reservoir sign, and that does not stiffen a handkerchief because it contains no mucin, suggests CSF. Bedside tests are the halo or double-ring sign on filter paper and a glucose level above 30 mg per dL, but the confirmatory test is beta-2 transferrin in the fluid, which is specific to CSF. The leak site is localised with high-resolution CT of the skull base, and persistent leaks are repaired endoscopically because of the meningitis risk.

If asked why glucose is unreliable: nasal secretions in a diabetic or a bloody sample also give a positive result.

What are the clinical features of allergic rhinitis and how do you treat it?

Allergic rhinitis is an IgE-mediated type 1 hypersensitivity producing paroxysmal sneezing, watery rhinorrhoea, nasal itching and obstruction, with pale, bluish, boggy turbinates on examination; in children the allergic salute and a transverse nasal crease are typical. I would advise allergen avoidance, give a second-generation oral antihistamine for symptoms and an intranasal corticosteroid spray as the most effective maintenance drug, and consider a leukotriene antagonist with co-existing asthma. Immunotherapy is reserved for patients with a single identified allergen who fail medical treatment.

A nasal smear showing eosinophils and a raised serum IgE support the diagnosis; skin prick tests identify the allergen.

When should a fractured nasal bone be reduced?

Ideally within the first few hours, before oedema sets in, or otherwise after the swelling settles, around day five to seven, but within about two weeks, because after that the fragments start to unite and closed reduction becomes impossible. Reduction is done with Walsham's forceps for the nasal bones and Asch's forceps for the septum, followed by a splint. On the day of injury I would always look for a septal haematoma, which must be drained immediately to prevent cartilage necrosis and a saddle nose.

The septal haematoma sentence is the reasoning the examiner is fishing for.

What are the orbital complications of sinusitis?

They follow Chandler's classification in increasing severity: preseptal cellulitis, orbital cellulitis, subperiosteal abscess, orbital abscess and cavernous sinus thrombosis. Ethmoidal sinusitis in children is the usual source because the lamina papyracea is thin. The warning signs that need urgent contrast CT and intravenous antibiotics are proptosis, chemosis, restricted or painful eye movements and any drop in visual acuity; a drained abscess and sinus surgery may be needed. Cavernous sinus thrombosis presents with bilateral involvement and ophthalmoplegia and is life-threatening.

Pott's puffy tumour, a subperiosteal abscess of the frontal bone from frontal sinusitis, is the common spotter in this group.

What are the indications and contraindications of tonsillectomy?

The absolute indications are recurrent acute tonsillitis meeting the Paradise criteria, that is seven episodes in one year, five a year for two years or three a year for three years, a second peritonsillar abscess, tonsillar hypertrophy causing obstructive sleep apnoea, and suspicion of malignancy. Relative indications include chronic tonsillitis with halitosis and tonsils as a focus of infection. Contraindications are an acute infection, a haemoglobin below 10 g per dL, a bleeding disorder, uncontrolled systemic disease, a polio epidemic and menstruation.

If asked why not during a polio epidemic: the raw tonsillar bed is a portal for the virus and bulbar polio.

Classify post-tonsillectomy haemorrhage and say how you manage reactionary bleeding.

Primary haemorrhage occurs during the operation, reactionary haemorrhage within 24 hours, usually from a slipped ligature or a rise in blood pressure as the patient recovers, and secondary haemorrhage around the fifth to tenth day from infection of the tonsillar fossa. For reactionary bleeding I would remove the clot from the fossa, apply pressure with a gauze soaked in adrenaline or hydrogen peroxide, start intravenous fluids, cross-match blood, and if bleeding continues, take the patient back to theatre to ligate the vessel under general anaesthesia. Secondary bleeding is usually managed with antibiotics and observation.

The sign of concealed bleeding in a child is repeated swallowing and a rising pulse. Mention it.

What is quinsy and how do you treat it?

Quinsy, or peritonsillar abscess, is a collection of pus between the tonsillar capsule and the superior constrictor muscle, usually following acute tonsillitis in a young adult. The patient has severe unilateral throat pain, odynophagia with drooling, trismus and a hot-potato voice, and on examination the tonsil and soft palate bulge medially with the uvula pushed to the opposite side. Treatment is incision and drainage at the point of maximum bulge, or needle aspiration, with intravenous antibiotics and analgesics, and an interval tonsillectomy about four to six weeks later.

Trismus is the examiner's keyword; it is caused by spasm of the pterygoid muscles from the adjacent inflammation.

What is Ludwig's angina and why is it an emergency?

Ludwig's angina is a rapidly spreading cellulitis of the submandibular space involving both sides and the sublingual space, usually arising from an infected lower molar. The floor of the mouth becomes woody, tender and swollen, pushing the tongue up and back, with fever and difficulty swallowing. It is an emergency because the swelling can obstruct the airway within hours; management is intravenous antibiotics covering anaerobes, securing the airway early, with tracheostomy if needed, and incision to decompress the space and remove the dental cause.

If asked why intubation is difficult: trismus, swelling and a tongue pushed backward. That is why a tracheostomy may be the safer airway.

How does a retropharyngeal abscess differ in a child and an adult?

An acute retropharyngeal abscess occurs in children under three or four from suppuration of the retropharyngeal lymph nodes after a throat infection; it presents with fever, dysphagia, stridor and a bulge on one side of the posterior pharyngeal wall. It is drained through the mouth without general anaesthesia, head low, to prevent aspiration of pus. A chronic retropharyngeal abscess in an adult is usually tuberculous, arising from caries of the cervical spine, lies in the midline behind the prevertebral fascia, and is drained externally through the neck with anti-tubercular treatment.

The X-ray clue is widening of the prevertebral soft tissue on a lateral neck film.

What are adenoids and how do you investigate and treat adenoid hypertrophy?

Adenoids are the nasopharyngeal tonsil, lymphoid tissue on the posterior wall of the nasopharynx that enlarges in childhood and normally regresses by puberty. Hypertrophy causes mouth breathing, snoring, nasal obstruction, adenoid facies, and middle ear effusion and recurrent otitis media by blocking the eustachian tube. I would confirm it with a soft-tissue lateral X-ray of the nasopharynx or nasal endoscopy, and treat with adenoidectomy when symptoms are significant, especially with recurrent otitis media or sleep apnoea.

Adenoid facies: open mouth, pinched nose, high-arched palate, crowded teeth and a dull expression.

What are vocal nodules and how are they treated?

Vocal nodules, or singer's or screamer's nodes, are small bilateral symmetrical thickenings at the junction of the anterior one-third and posterior two-thirds of the vocal cords, the point of maximum vibration, caused by vocal abuse in teachers, hawkers, singers and children. They present with hoarseness and vocal fatigue. Early nodules resolve with voice rest and speech therapy to correct the vocal technique; mature fibrotic nodules that fail conservative treatment are excised by microlaryngeal surgery, followed by speech therapy to prevent recurrence.

A vocal polyp, in contrast, is unilateral and usually follows a single episode of vocal abuse.

A 60-year-old smoker has had hoarseness for six weeks. What would you do?

Hoarseness persisting beyond three weeks in a smoker is carcinoma of the larynx until proved otherwise, so I would do an indirect laryngoscopy in the clinic, followed by direct laryngoscopy and biopsy under general anaesthesia if any lesion or cord immobility is seen. I would examine the neck for nodes and get a CT of the larynx and neck for staging. Glottic cancer is the commonest laryngeal cancer and has the best prognosis because the cords have few lymphatics, so early lesions are cured with radiotherapy or laser excision; advanced disease needs laryngectomy with voice rehabilitation.

'Why does glottic cancer present early?' Because even a small lesion disturbs cord vibration and causes hoarseness.

What are the indications for tracheostomy?

I group them into four. First, relief of upper airway obstruction from infections, tumours, foreign bodies, trauma or bilateral abductor palsy. Second, removal of retained secretions in patients who cannot cough, such as the comatose, those with head injury or bulbar palsy. Third, respiratory insufficiency needing prolonged ventilation, where a tracheostomy reduces dead space and makes suction easier. Fourth, as an elective step before major head and neck surgery. The emergency alternative when there is no time is cricothyrotomy.

Be ready for the levels: high above the thyroid isthmus, mid through the second to third rings at the isthmus, low below it.

What are the complications of tracheostomy?

Immediate complications are haemorrhage, injury to the recurrent laryngeal nerve or oesophagus, apnoea from sudden loss of hypoxic drive, and pneumothorax, especially in children. Intermediate complications are tube blockage by crusts, displacement, subcutaneous emphysema, infection and tracheitis. Late complications are tracheal stenosis, tracheo-oesophageal fistula, tracheocutaneous fistula and a difficult decannulation. The commonest cause of sudden distress in a tracheostomised patient is a blocked tube, so my first step is to remove and clean the inner tube and suction.

The inner tube reasoning is exactly why examiners prefer tubes with an inner cannula; connect the two answers.

How do you interpret the type of stridor?

Inspiratory stridor indicates obstruction at the supraglottis or glottis, because the negative pressure of inspiration collapses the soft tissues above the cords. Biphasic stridor points to the subglottis or upper trachea, which is a rigid segment that narrows airflow in both directions. Expiratory stridor or wheeze suggests the lower trachea or bronchi, because intrathoracic airways narrow on expiration. In an infant, the commonest cause of chronic stridor is laryngomalacia, which is inspiratory, worse supine and crying, and usually resolves by two years.

Two emergency causes in a child the examiner expects: acute epiglottitis with the thumb sign and croup with the steeple sign.

Why is left recurrent laryngeal nerve palsy commoner than right, and what are the causes?

The left recurrent laryngeal nerve has a longer course, looping under the arch of the aorta in the chest, so it is exposed to more diseases: bronchogenic carcinoma, an aortic aneurysm, enlarged mediastinal nodes and an enlarged left atrium. Both nerves can be injured in thyroid surgery, which is the commonest surgical cause, and by thyroid or oesophageal cancer. A unilateral palsy gives a weak breathy voice with aspiration; a bilateral abductor palsy leaves the cords in the median position with a good voice but a dangerous airway that needs a tracheostomy.

If a palsy is idiopathic, the examiner wants you to say you would image from the skull base to the mediastinum before calling it idiopathic.

A child inhaled a peanut. Where does it lodge and how do you remove it?

An inhaled foreign body usually lodges in the right main bronchus because it is wider, shorter and closer to vertical than the left. A peanut is especially dangerous because its oil causes an intense chemical bronchitis, and it swells and fragments. The child presents with a choking episode followed by cough, unilateral decreased air entry and wheeze, and the chest X-ray may show obstructive emphysema on expiration rather than the object itself. Removal is by rigid bronchoscopy under general anaesthesia with the right forceps, never by blind finger sweep or inducing vomiting.

Oesophageal foreign bodies lodge most often at the cricopharynx; a coin shows en face on an AP film.

What is Plummer-Vinson syndrome?

Plummer-Vinson or Paterson-Brown-Kelly syndrome is the combination of iron deficiency anaemia, dysphagia due to a post-cricoid web, and features such as glossitis, angular stomatitis and koilonychia, seen typically in middle-aged women. It matters in ENT because the web is treated by dilatation along with iron replacement, and because the condition is premalignant for post-cricoid carcinoma, so the patient needs long-term follow-up.

Barium swallow shows the web; oesophagoscopy confirms it and allows dilatation.

What is a thyroglossal cyst and what is the operation for it?

A thyroglossal cyst is a midline neck swelling arising from a persistent thyroglossal duct, the embryonic track of the thyroid from the foramen caecum of the tongue to its final position; it lies most often at or just below the hyoid. The diagnostic sign is that it moves upward on protrusion of the tongue as well as on swallowing. Treatment is Sistrunk's operation, which removes the cyst with the whole tract and the central part of the hyoid bone, because leaving the tract leads to recurrence or a fistula. I would confirm with ultrasound that a normal thyroid is present before surgery.

A branchial cyst, by contrast, lies at the upper third of the anterior border of the sternocleidomastoid.

Identify this: a metal mouth gag with a tongue-depressing blade held on two upright rods.

This is the Boyle-Davis mouth gag, used in tonsillectomy and adenoidectomy to keep the mouth open and the tongue depressed, suspended on Draffin bipods so the surgeon has both hands free. The blade has a groove for the endotracheal tube. Its use is in the Rose position, with the neck extended and head low, so that blood runs into the nasopharynx rather than the larynx.

Follow-up: name the other tonsillectomy instruments on the table — Denis Browne tonsil holding forceps, Mollison's dissector and pillar retractor, Eve's tonsil snare, Negus artery forceps.

What is this bayonet-shaped forceps with long angled blades?

This is Tilley's nasal dressing forceps, used to introduce ribbon gauze for anterior nasal packing in epistaxis, to remove crusts in atrophic rhinitis and to place medicated packs after septal surgery. The bayonet shape keeps the surgeon's hand out of the line of vision when working through the nostril. For a pack I lay the ribbon gauze in layers from the floor upwards and backwards, the whole length into the nose, and remove it in 48 to 72 hours under antibiotic cover.

Luc's forceps, with its cupped fenestrated blades, is the one for grasping and avulsing nasal polyps; do not confuse the two.

Name these two tracheostomy tubes and give the difference.

The metal one is Jackson's tracheostomy tube, made of silver or stainless steel with an outer tube, an inner tube and an obturator; the inner tube is longer than the outer, so it can be taken out and cleaned without disturbing the airway, which makes it suitable for long-term use. The plastic one is a Portex cuffed tube, used when the patient needs positive-pressure ventilation or protection from aspiration, because the inflated cuff seals the trachea. Fuller's bivalved tube is the other classic, with a split inner tube and a speaking valve.

If asked about the cuff: keep pressure low and deflate it periodically to prevent tracheal mucosal ischaemia and stenosis.

What is this: an aural speculum with a rubber bulb and a lens?

This is Siegle's pneumatic speculum. It magnifies the tympanic membrane and, by squeezing the bulb, applies alternating positive and negative pressure to the ear canal to test the mobility of the drum. A healthy drum moves; a drum with a middle ear effusion, adhesions or a tympanosclerotic plaque moves poorly, and a perforation gives no movement at all. It is also used to perform the fistula test, where pressure produces vertigo and nystagmus if there is a labyrinthine fistula.

The fistula test answer shows applied knowledge and usually ends the instrument round on a good note.

Why is a 512 Hz tuning fork used for hearing tests?

A 512 Hz fork is the compromise frequency: lower-frequency forks such as 256 Hz are felt as vibration through bone and overestimate bone conduction, while higher-frequency forks such as 1024 Hz decay too quickly to complete the test. The 512 Hz fork is therefore the standard for Rinne's, Weber's and the absolute bone conduction test, struck on the elbow or a rubber pad, never on a hard surface, so that it produces a pure tone without overtones.

The absolute bone conduction test compares the patient's bone conduction with the examiner's, assuming the examiner's hearing is normal.

Identify this: a long curved trocar and cannula.

This is Lichtwitz's trocar and cannula, used for antral puncture and lavage of the maxillary sinus. It is passed through the inferior meatus, below the inferior turbinate about one and a half centimetres from its anterior end, directed towards the outer canthus of the same eye, because the medial wall is thinnest there. It was used both to diagnose and to irrigate chronic maxillary sinusitis; today endoscopic surgery has largely replaced it, but it remains a standard viva instrument.

Complications: injury to the orbit or the cheek if misdirected, and air embolism if air is pushed in. Say 'I irrigate with saline, never air'.

What are these: a curette with a ring on one end and a probe on the other, and a curette with a guard?

The first is the Jobson Horne probe and ring curette, used to remove wax and small foreign bodies from the ear canal and to take swabs with cotton wound on the probe end. The second is St Clair Thomson's adenoid curette with a guard, used in adenoidectomy to scrape the adenoid mass off the posterior nasopharyngeal wall in one sweep, the guard preventing fragments from falling into the airway. Modern adenoidectomy is increasingly done under endoscopic vision with a microdebrider or coblation.

Also on the table: the head mirror. It is concave, focal length about 25 cm, with a central hole so the examiner looks along the line of the reflected light.

A tracheostomised patient suddenly becomes restless and breathless on the ward. What do you do?

I assume the tube is blocked until proved otherwise. I would remove the inner tube and clean it, suction the outer tube, and instil a few drops of saline to loosen crusts. If there is no improvement I check whether the tube has been displaced into the pretracheal tissue and, if so, replace it with a fresh tube or the tracheal dilator kept at the bedside. I would give oxygen throughout and call for help; a chest X-ray later excludes pneumothorax and surgical emphysema.

Examiners want to hear that the spare tube, dilator and suction are at the bedside before the emergency, not after.

An adult presents with stridor and drooling after a few hours of severe sore throat. What is your approach?

This picture suggests acute epiglottitis, a cellulitis of the supraglottis classically caused by Haemophilus influenzae type b, which can obstruct the airway rapidly. I would not examine the throat with a tongue depressor or lie the patient down, because that can precipitate complete obstruction. I would keep the patient sitting, give oxygen, secure the airway in a controlled setting with the anaesthetist and an ENT surgeon ready for tracheostomy, and then start intravenous antibiotics and steroids. A lateral neck film shows the thumb sign but should not delay airway management.

The reasoning line is 'airway before investigation'. Say it in those words.

What is the first thing you do for a patient with a bleeding nose on an anticoagulant?

The first step is the same as for any epistaxis: sit the patient up, pinch the nose, and assess the pulse and blood pressure while securing intravenous access, because the anticoagulant makes a large bleed more likely. I would then control the bleed locally with cautery or packing, send blood for a coagulation profile, haemoglobin and grouping, and discuss with the physician whether to withhold or reverse the anticoagulant, which depends on the indication, for example a mechanical valve versus atrial fibrillation.

Examiners check that you do not stop warfarin on your own in a valve patient. 'Discuss with the physician' is the right phrase.

What is cavernous sinus thrombosis and how do you recognise it?

Cavernous sinus thrombosis is septic thrombosis of the cavernous sinus, spreading from infections of the dangerous area of the face, the ethmoid or sphenoid sinuses or the orbit, through valveless veins. The patient is toxic with high fever, severe headache, chemosis, proptosis and ophthalmoplegia because the third, fourth and sixth nerves run in the sinus wall, and the signs typically become bilateral within a day or two, which distinguishes it from an orbital abscess. It needs urgent contrast CT or MR venography, high-dose intravenous antibiotics and drainage of the primary source; anticoagulation is debated.

'Why bilateral?' Because the two cavernous sinuses communicate through the intercavernous sinuses.