A 37-year-old male has been admitted to your ICU following an explosion in his garage. He has suffered a mixture of partial and deep burns estimated at 35% total body surface area, and he has been intubated in the Emergency Department. After one hour of resuscitation in your unit he remains hypotensive with a blood pressure of 80/50 mmHg.
List the potential causes and outline how you would diagnose and manage them.
Examiners Comments:
Frequently poorly structured answer, with a list of causes of hypotension, then repeated with diagnosis and management. Worked better when candidates classified each category of shock, then described individual diagnosis and management within each category. Often the question had not been carefully read, and the time already spent in ED and ICU was ignored; then a simplistic EMST initial approach to trauma was given.
This question resembles Question 26 from the second paper of 2016, except the patient is not unconscious and there is no ABG to interpret.
Let this be an exercise in generating differentials.
If one were to offer more detail, one would have to tabulate one's answer, which would handily answer complaints about a lack of structure, because nothing says "structure" like a table.
Type of shock | Cause | Diagnostic strategy | Management |
Artifact of measurement | Arterial blood pressure measurement is inaccurate | Compare with non-invasive measurement and physical examination |
|
Cardiogenic | Cytokine-induced myocardial dysfunction Alternatively, cardiac dysfunction can be associated with cyanide and carbon monoxide toxicity |
TTE, ECG, cardiac output measurement by PiCCO or PA catheter |
|
Myocardial infarction | TTE, ECG, cardiac enzymes |
|
|
Obstructive | Abdominal compartment syndrome | Measure the intra-abdominal pressure; calculate total fluid resuscitation (it is associated with over-resuscitation) |
|
Massive pulmonary embolism (unlikely - too early - more likely in the chronic recovery from burns) |
TTE, CVP trace, ECG, CTPA |
|
|
Tension pneumothorax (likely, if there the patient was in some sort of explosion) |
Physical examination; CXR |
|
|
Neurogenic | Spinal injury due to fall; may have gone unrecognised given that the patient was found unconscious | Physical examination features, CT, MRI |
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Hypovolemic | Blood loss | Examination of the patient, FBC, DIC screen |
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Under-resuscitated burns shock | Compare fluid resuscitation with predicted expectations as based on the formulae |
|
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Distributive | Vasoplegia due to SIRS | SVRI measurements by PiCCO |
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Anaphylaxis | Physical examination findings suggestive of angioedema |
|
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Cytotoxic | Cyanide toxicity due to smoke inhalation | Lactate levels; cyanide levels |
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