Explaining mastoiditis, admission and the surgical decision — OSCE

Candidate instructions (8-minute station)

You are the paediatric registrar in the emergency department. A 14-month-old has three days of fever, coryza and ear-pulling, started on oral amoxicillin yesterday for acute otitis media. Today the child is more unsettled and febrile, with right postauricular erythema, swelling and tenderness, a lost postauricular crease, the pinna pushed downward and outward, and a bulging erythematous tympanic membrane. The parent is anxious and wants to know whether the ear is serious, whether the antibiotic syrup is enough, whether the child needs to stay in hospital, and whether an operation is needed. [4]

Your tasks are: [4]

1. Explain the diagnosis of acute mastoiditis in plain language and why it is more than a simple ear infection. [4]
2. Explain why the child needs admission and intravenous antibiotics rather than oral syrup, and outline the plan for a myringotomy and the 48-hour reassessment. [8]
3. Explain the possible need for a scan and for surgery, including the cortical mastoidectomy, and the 48-hour decision point. [8] [5]
4. Give a clear, specific safety-net for the signs that would mean the infection has spread towards the brain and needs urgent escalation. [1]

You are not expected to prescribe the intravenous regimen in detail to the parent, but you should explain the plan clearly and honestly, including the possibility of an operation. [5]

Examiner prompt to the actor (parent)

"She was started on the antibiotic syrup only yesterday and she is worse today — is the medicine not working? The back of her ear looks so swollen, is the infection spreading to her brain? Does she really need a drip and to stay in hospital, and will they have to operate on her? I am frightened." [4]

Marking domains

• Frame and explanation of the diagnosis (3): explains acute mastoiditis as an infection that has spread from the middle ear into the honeycomb of bone behind the ear (the mastoid), which is why it is more serious than the simple ear infection she started with; names that the swelling and the ear being pushed down and outward are the signs that the bone behind the ear is infected and obstructed; is honest that it is serious but treatable. [4]
• Admission and intravenous antibiotics with the myringotomy and 48-hour plan (3): explains that because the bone behind the ear is infected, the antibiotic needs to go straight into the bloodstream through a drip rather than by mouth, so the child needs to stay in hospital; explains that a small cut in the eardrum (a myringotomy) relieves the pressure and helps drain the pus; explains that the team will watch closely and reassess at 48 hours to see whether the antibiotics alone are working or whether an operation is needed. [8]
• The scan and the surgical decision (2): explains that a scan (a CT) may be needed to look for a collection of pus behind the ear or any spread; explains honestly that an operation called a cortical mastoidectomy to clean out the infected bone may be needed if the child does not improve on the drip, if pus collects, or if there is any sign of spread, and that the decision is made at the 48-hour reassessment or sooner if the child deteriorates. [8] [5]
• Safety-net for intracranial spread (2): tells the parent to call the nurse straight away if the child becomes drowsy or hard to wake, develops a severe headache, a stiff neck, vomiting, a squint or double vision, a fit or seizure, or becomes more unwell with a high swinging fever — because those signs would mean the infection may be spreading towards the brain and would need an urgent scan, neurosurgery and stronger treatment. [1]

Model answer — the explanatory script

"Thank you for bringing her in. I can see how swollen and uncomfortable she is, and I understand why you are frightened. I have examined her carefully, and I want to be honest with you — this is more than the simple ear infection she was treated for yesterday. The infection has spread from inside the ear into the honeycomb of bone just behind the ear, called the mastoid. That is why the skin behind her ear is red and swollen, and why her ear is being pushed down and sticking out — the bone behind it is infected and full of pus under pressure." [4]

"The antibiotic syrup she started has not had time to fail — this has just moved on quickly, which mastoiditis sometimes does. Because the bone behind the ear is now infected, the medicine needs to reach it through the bloodstream directly, so she needs the antibiotic through a drip in hospital rather than by mouth. She does need to stay in. We will also make a tiny cut in the eardrum, called a myringotomy, to let the pus out and relieve the pressure — that helps the infection settle and lets us find out which germ is causing it." [8]

"Most children respond well to the drip and the myringotomy, but not all. We will watch her very closely and look again at 48 hours. If she is not improving by then, or if we find that pus has collected behind the ear or spread, she may need a scan — a CT — and an operation called a cortical mastoidectomy, where the surgeon cleans out the infected bone behind the ear. I cannot promise she will avoid an operation, but I can promise we will make that decision at the right time, and sooner if anything changes. The ear, nose and throat surgeon is already involved." [8] [5]

"The one thing I most want you to watch for is whether the infection spreads towards the brain, which is the serious complication we are guarding against. Please call the nurse straight away if she becomes drowsy or hard to wake, complains of a bad headache or develops a stiff neck, keeps vomiting, develops a squint or double vision, has a fit or seizure, or becomes more unwell with a high fever that keeps spiking up and down. Any of those would mean we need to scan her urgently and bring in the neurosurgical team. Those signs are not common, but they are the ones that matter, and I would rather you pressed the call button than waited." [1]

"I know this is a lot to take in. The short version is this: she has an infection in the bone behind her ear, it needs antibiotic through a drip in hospital, a small procedure to drain the ear, and close watching for two days, and an operation is possible but not certain. We will keep you informed at every step." [5]