Practice this case based on how you are assessed in your OSCEs, and use the relevant sections for general revision. 🤓
Doctor Instruction:
You are a doctor working in the emergency department. Your next patient is a 45-year-old gentleman (Ian Smith) coming in due to having "tea" coloured urine. Please take a history and perform an appropriate examination.
Patient History:
Your name is Ian Smith. You are a 45 years old man working as an office worker.
You come in today because you noticed something weird with your urine - it is becoming more "tea" coloured or red-brown coloured. This happened after running a marathon 1 day ago, which you wanted to do for a long time because you were quite unfit working in an office job and wanted to challenge yourself. You are worried because you are unsure if this is blood, and you cannot see any fresh blood. You feel hopeless as you could not even finish the first half of the marathon – it just shows how unfit you are! Since then, your lower legs have been quite sore with some swelling from running. Some numbness and tingling sensations around the calves. You also feel exhausted due to the race and sometimes have nausea and vomiting.
If asked specifically:
You feel like you are as dry as a bone – you are producing very little urine at the moment – no difficulty/ pain when passing urine. You haven't been drinking much water as not a "water-loving person" - maybe only a few glasses of liquid a day
Never had this problem with urine before. No other urinary symptoms.
Not eaten anything e.g. beetroot which may stain the urine
No history of falls / long lie/ immobilisation/ trauma/ injuries
No fever
Idea, Concern, Expectation:
You think you might have caught a urinary tract infection or maybe not drinking enough water. You are concerned if you are bleeding somewhere from the bladder - making the urine more red and brown. You want your urine colour to return to normal and possibly get some antibiotics.
Past Medical History:
Hypertension, hyper-cholesterol, obesity
Drug History:
Statin, ramipril
Not on anticoagulation.
No over-the-counter medications
NKDA
Family History:
None
Social History:
Drink alcohol occasionally - maybe a glass of red wine every other day.
Do not smoke
Do take substances recreationally, but you don't know what they are.
Live with your parents in a house
Work in an office for recruitment
No travel history
Examination Findings:
Alert and orientated
Mild swelling in both calves with tenderness - associated with weakness in movement and altered sensation.
Peripheral pulses are present with a heart rate of 114 bpm. BP normal.
Dry mucous membrane. Capillary refill time normal. Skin turgor normal.
Differentials:
Rhabdomyolysis - due to the soft tissue breakdown following a marathon and red-brown urine. This can lead to AKI.
Dehydration - the patient doesn't seem to take many fluids. High HR and dry mucous membrane suggest dehydration. This can lead to AKI.
To Rule Out Urinary Tract Infection - there is a change in the colour of urine - UTI might be possible. However, the symptoms & signs occurred after the marathon with associated muscle pain/swelling, making rhabdomyolysis more likely.
To Rule Out Compartment Syndrome - a possibility with pain, swelling and paraesthesia. This can occur secondary to an injury. This is a surgical emergency.
To Rule Out Deep Vein Thrombosis (DVT) - very unlikely. This young individual has not been immobile, he has been quite the opposite. A bilateral DVT is also unlikely, as they are usually unilateral.
Investigations:
Bedside:
ECG - may show tall tented T-waves, flattening or widening of P-waves, PR prolongation in hyperkalemia caused by muscle breakdown. Tachycardia may also result due to pain or dehydration.
Urine Dip - positive for blood in rhabdomyolysis. The heme can be detected from the myoglobin excreted in the urine from muscle death in rhabdomyolysis. Leucocyte/ nitrites might be positive for infection.
Urine Culture, Sensitivity & Microscopy - assess urine sediments for the presence of RBC. If there are RBCs, then a positive urine dipstick for heme would likely be due to RBC rather than myoglobin. Culture and sensitivity to assess for infection and guide antibiotic treatment.
Urine/Serum Myoglobin - if available; may be elevated and is a non-specific test for muscle injury.
Well's score for DVT
Bloods:
Blood Gas - it will also give you a quick result for electrolyte imbalance which enables starting treatment early. Useful for assessing for metabolic acidosis which can be caused by increased uric acid levels from excessive cell breakdown.
Creatinine Kinase - raised in rhabdomyolysis. An enzyme found in muscle cells which can be released on muscle breakdown/cell death. It can be mildly elevated following normal exercise. It can be markedly elevated in myocardial infarction, and especially raised in Rhabdomyolysis.
Urea & Electrolytes - may show hyperkalaemia & AKI. Don't forget to compare U&Es to previous baseline renal function. Potassium (a mostly intracellular electrolyte) is released upon cell death, therefore can lead to arrhythmias in rhabdomyolysis. Myoglobin (toxic to the renal tubules) may lead to a rise in creatinine; indicating an AKI.
Bone Profile - Hyperphosphataemia & Hypocalcaemia. Phosphate is released from the breakdown of muscle cells. Calcium may enter damaged muscle cells and become deposited in them - reducing serum calcium.
Liver Function Tests - Hepatic injury & baseline. Hepatic injury may result from rhabdomyolysis. It's also good to establish a baseline result.
Coagulation Studies - Disseminated intravascular coagulation is a complication of rhabdomyolysis. Potential uncontrolled bleeding.
Full Blood Count + C-Reactive Protein - may be raised in infection.
ESR (inflammatory myopathies)
Toxicology Screen (to evaluate illicit drug, opiate, alcohol use)
Imaging:
Consider USS Doppler lower limbs to rule out DVT if suspected. D-dimer might be used to rule out DVT initially.
Consider USS/CT KUB for renal tract pathology if appropriate.
Special Test:
Compartmental Pressure Measurement - if concerned for compartment syndrome. Most cases are based on history and examining findings.
Consider Muscle Biopsy (genetic)
Data Interpretation: