The following uncommon case histories are presented as challenging emergency situations especially as these conditions are frequently misdiagnosed.

1　Cases

1.1Case A:Acute respiratory distress 2 days after traumaA 30 year man sustained a fractured pelvis after he fell 3 metres from a ladder.He is admitted to hospital for pain intravenous fluids and pain management.Two days later he developed unexplained sudden deterioration of his health with confusion,agitation and shortness of breath.

On examination he has a petechial rash on the anterior chest,neck,axilla,conjunctiva and inside his mouth on the mucous membranes.

His vital signs pulse 120/min,respiration 20/min,temperature 38 ℃,blood pressure 100/65 mm Hg,PaO255 mm Hg.

Questions:(1)What is your provisional diagnosis? (2)What investigations would be appropriate at first?

1.2Case B:A banging noise behind the eye after facial injuryA 50 year old was was struck over the left side of his forehead and eye by a metal bar during an assault in a street brawl.His black and swollen eye gradually improved but after a few days he started to complain of a persistent banging or whooshing sound ′like the wind′ behind his left eye.He also complained of headache and tinnitus in his left ear.

On examination he had a red left eye with hyperaemia of the conjunctiva.When a stethoscope was placed over the eye a high pitch bruit (murmur) was audible over the orbit.The bruit corresponded with the heart beat.

Questions:(1)what is your provisional diagnosis? (2)What is the appropriate investigation ?

1.3Case C:Unexplained stroke in a healthy adolescentA 15-year-old schoolgirl who had been in perfect health was found in the early hours of the morning,collapsed on the floor of her bedroom.Her parents had been awoken by a loud noise (presumably due to her falling) and had found her lying on the floor unable to speak with a right hemiparesis.

On examination in the emergency room she was unable to speak or understand the spoken word.She had a dense right hemiparesis involving the arm,leg and face and swallowing was impaired.There was no neck stiffness.Cardiac examination was normal.There was no evidence of bruits in the neck,ocular fundi were normal and no evidence of emboli or blood in the urine.Routine haematology and urine tests,ECG and chest X-ray were all normal.

Questions:(1)What is your provisional diagnosis? (2)What further investigations are appropriate in this girl?

2　Answers

2.1Case A(1)The man with major trauma to his pelvis has a fat embolism whereby fat droplets from an open fracture enter the systemic venous circulation and embolise to the lungs.The pulmonary syndrome is similar to acute respiratory distress syndrome (ARDS).(2) First line investigations should be a chest X ray and examination of the sputum and urine for fat droplets.The treatment is oxygen by mask.

2.2Case B(1) This man has a carotid-cavernous sinus fistula caused by a traumatic communication between the arterial and venous systems within the cavernous sinus due to a rupture of a branch of the internal carotid artery.(2) Imaging is necessary to confirm the diagnosis either with a CT scan or magnetic resonance imaging and cerebral angiography (the gold standard).The defect was sealed by an imaging guided latex balloon.

2.3Case C(1)This adolescent girl has a paradoxical embolus also called cryptogenic stroke.It can commonly occur with a patent foramen ovale,atrial septal defect or ventricular septal defect.(2)Further investigations in this person included a CT scan of the brain,angiography and tests for thrombophilia including lupus anticoagulation screen.These tests revealed cerebral infarction but no haematological disturbances,However a transoesophageal echocardiograph using a contrast demonstrated right to left shunting through a large patent foramen ovale.The defect can be closed with a percutaneous image guided ′umbrella′ device.