This next case is a fascinating example of how CT scanning might have been helpful in establishing a diagnosis under these correct circumstances and indications. The case has been anonymised to safe guard patient confidentiality. This case is from the UK, not Japan, and is the unfortunate experience of a colleague of mine from several years ago.
Presenting Complaint
49 year old patient admitted with COLLAPSE
History of Presenting Complaint
He was normally fit and well and worked in a factory. Patient had been at pub in the afternoon when he stood up and suddenly collapsed to the floor. He lost consciousness for a few minutes only. Paramedics were called and patient was brought to the local ER department.
On arrival patient was grey in colour and sweating profusely and his T-Shirt was soaked with sweat.
Airway patent
Breathing- normal RR-16/min, SpO2 100% on oxygen via rebreath bag
Circulation BP 80/40 in both arms and pulse 100 beats per min and regular
GCS 15/15
Temp 37.5 Dry mucous membranes. Patient overweight
CVS: JVP not seen as patient had a large neck
Heart sounds 1 + 2 and normal. No added sounds / murmurs. No peripheral oedema
Resp: Percussion Resonant, chest clear, no wheeze / crepitations
Abdo: Soft , but epigastrium / peri-umbilical tenderness, No rebound / guarding, No hepatosplenomegally, Bowel Sounds present. Rectal- normal stool.
Central Nervous System: Pupils equal and reactive to light. All Cranial Nerves normal.
Peripheral Nervous System- tone, power, reflexes, plantar responses WNL.
ECG: Slight ST flattening in V5/V6 but no elevation/depression
CXR: Normal cardiac size. Nil acute.
Clinical Impression: Collapse with shock ? cause
Two intravenous lines inserted and fast IV fluid given. Urinary catheter placed— clear urine obtained.
Blood pressure improved to systolic of 100mmHg and pt was stabilized to be moved into observation area.
Now patient being more alert, he could answer more questions:
When he collapsed he was not sure what happened. He denied tongue biting / urinary incontinence / seizure and no seizure was witnessed by bystanders. He had slight abdominal discomfort only. No palpitations / no headache / no dizziness normally when standing.
No chest pain / neck-arm pain. No previous collapses in his life.
He admitted to recent diarrhoea and he had eaten mussels the previous evening but his wife and daughter had not eaten them. The mussels had been frozen and cooked in the microwave. He admitted to only one episode of diarrhoea. The abdominal pain was more of a discomfort but was not associated with any further diarrhoea. He felt thirsty. No blood in stool.
Medications: No regular drugs
Family History: Nil of note
Social History: Drank alcohol 2 pints/day, Non-smoker, Lived with wife and daughter in a house
Blood Results
Hb 13.4 Urine- NAD
WCC 12.4
N% 70%
Plts 300
MCV 82.3
CRP/ESR not tested
Na 134
K 4.5
BUN 28.8
Creat 1.58
Liver function tests normal
CK normal. Troponin-I WNL.
Arterial Blood Gas:
Metabolic Acidosis pH 7.31, low HCO3, BE -3, PCO2 low and normal PO2 on air.
Problem List
Collapse with shock
Abdominal Discomfort and Diarrhoea
Mild Renal failure
Metabolic Acidosis ? second to renal failure ? Lactic acidosis from organ hypoperfusion
History of sea food ingestion
Differentail Diagnosis
Possible severe invasive GI food poisoning and volume depletion from diarrhea ? Salmonella infection/ E. Coli 0157:H7
? Ischaemic bowel
?? evolving Silent MI (only flattening of ST segment and normal CK and Trop I but maybe too early)
??? Aortic Dissection (normal CXR, no differential pulses but profound hypotension)
PLAN
Continued fluid resuscitation
Abdominal Xray
Stool culture
Antibiotic treatment with ciprofloxacin for ‘travellers diarrhoea’
Arrange CT thorax and abdomen: doctor had to speak with the Consultant On-Call at home to get pemission to do an 'out of hours' CT scan.
Close observation
Patient then moved to Medical Care unit
Blood pressure was stable and systolic improved to 120mmHg and urine output initially adequate.
The Hospital Doctor discussed the patient with the 'on-call' Consultant who was at home sleeping!—HOWEVER, the Consultant was not convinced from the history, physical and ensuing test results that the patient had an aortic dissection, so an emergency scan was refused!!
AXR- not focal abnormality detected.
Patient still complaining of abdominal discomfort and so the on-call hospital doctor re-examined. No changes evident from admitting examination.
Pulse was still tachycardic despite adequate volume filling and urine output then decreased to <20ml/hour. Patient was now complaining of feeling breathless.
Chest was re-examined and was entirely clear.
The On-call doctor then considered, however unlikely, that the patient may have sustained a Pulmonary Embolism as this may cause abdominal pain and dyspnoea.
Repeat ABG on air showed no hypoxia, but Metabolic Acidosis had worsened significantly pH 7.22, BE -10, low HCO3 and CO2. Normal PaO2.
Very soon afterwards, the patient then started to scream and became confused and I am told that he said 'I cannot breath, I cannot breath' and then he collapsed on his bed.
Cardiac Arrest Call was put out
Pt had a non-shockable rhythm and despite 30 minutes of intense cardiopulmonary resuscitation, he was unable to be revived.
What was the diagnosis???
On reviewing the history, data and clinical picture, the doctor considered that the patient may have had a severe type of food poisoning e.g. E.Coli 0157:H7 due to renal failure and shock with recent history of diarrhoea.
On the other hand, the on-call hospital doctor considered that however unlikely, with nothing else otherwise fitting the clinical picture, the patient may have developed an aortic dissection. But, how could this be?
This patient had none of the classical symptoms and signs of dissection. There was no history of chest pain, no interscapular pain and no pulse differential. The feeling of breathlessness may have been due to metabolic acidosis, but a metabolic acidosis does not give you ‘Air Hunger’. Kussmaul's respiration , as seen in a diabetic ketoacidosis, is however similar to air hunger but in this case, the pH of 7.22 was probably not low enough to give a severe Kussmaul's-type picture.
Air Hunger occurs when the patient has insufficient cardiac output to maintain normal respiration and is a sign of acutely impending cardiovascular collapse.
Did this patient have an acute cardiac tamponade and a distal dissection too? This would mean that there would have to be a large proximal-distal dissection with GI and renal arteries involved.
Plan
Post-Mortem was arranged through the local government investigative officer (known as the coroners officer whose legal duty is to investigate all unusual deaths) and Toxicology/Microbiology investigation
Post-mortem the next day—the On-Call doctor was in attendance.
Diagnosis: Cardiac Tamponade and Dissection of thoracic and abdominal aorta.
No major neck arteries had been affected. The pericardial sac contained approx. 500ml blood and the heart chambers were empty of blood. The Aortic Valve had a small tear and there was the classical fibrinoid changes seen in the dissection area. The Aorta was stripped by the dissection and there was a false lumen. The renal arteries had been affected too.
The On-Call doctor had been correct about the diagnosis and correct to inform his senior of his concerns about the suspicion of Aortic Dissection, but the Consultant, having not seen the patient himself, had simply not appreciated the extent of the patient's severity and had clearly made a error of judgement in refusing to allow for an emergency CT scan.
However, even if this patient had had an emergency CT scan, which would have probably been diagnostic of a Dissection, at this Hospital there were no Cardiothoracic Surgical Specialty services and he was too unstable to be moved to a Specialist centre in time for the extensive cardiovascular surgery that he ultimately required.
If the patient had have been scanned earlier, or if the Echocardiographic services had been available out of hours, then the diagnosis would have been confirmed much sooner, but again it is very unlikely that this patient could have been saved in time.
Clinical Gem From This Case:
If you consider dissection then it must be excluded. Dissection may not give chest pain and the Chest Xray may be completely normal initially, but it can present with sudden collapse and shock and abdominal pain. Metabolic acidosis in this case was probably due to organ ischaemia. The worsening renal failure over hours despite adequate fluid input and adequate systolic BP should be a cause of concern and warrant further investigation.
It would be useful for junior doctors to be taught the basic skill of ultrasonography / echocardiography, just like in Japan, as these non-invasive techniques can again give valuable information to the physician especially in emergency situations.
If you have any comments on the above then please let me know.
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