A 28-year-old male presents to the primary care office for evaluation of left calf pain, swelling, and redness. He reports that this started one day ago and worsened today. He ran a 27-mile marathon 2 days ago and traveled for 3 hours in a car today. He reports slight pain on walking and a swollen red calf. He took Ibuprofen 600 mg twice today without relief. Patient reports being an experienced runner, running 3-5 miles daily. He trained for the marathon for 4 months. Patient also reports a history of exercise induced asthma and uses albuterol sulfate HFA as needed.
On physical exam patient appears in good health T 99 P 68 R 18 BP 118/78 wt. 175 lb, height 72 in. BMI 23.1. Heart rate is regular without murmurs, rubs, or gallops. Lungs clear bilaterally. HEENT WNL. Strength lower extremities +5 and DTRs + 2. Left calf erythematous, edematous, warm and tender on palpation. Pulses 3+.
Two possible diagnoses were considered: deep vein thrombosis (DVT) and rhabdomyolysis.
Stat ultrasound of left leg to rule out DVT was ordered and read as normal
CBC WNL
Creatine Kinase (CK) 23,000 U/L (normal 24-170 U/L)
BUN and Creatinine WNL
A diagnosis of rhabdomyolysis was made.
1) What is the pathophysiology associated with this diagnosis? 2) Why do the supplied diagnostic test results support this diagnosis? 3) What are the risks associated with this diagnosis? 4) What type of treatment(s) would assist this patient in alleviating his symptoms?
Full Answer Section
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Alcohol Abuse: Excessive alcohol consumption can damage muscles and lead to rhabdomyolysis.
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Underlying Conditions: Certain conditions, like hypothyroidism, electrolyte imbalances, and certain genetic disorders, can increase the risk of rhabdomyolysis.
In this case, the patient's intense exercise (marathon) likely triggered the rhabdomyolysis. The prolonged activity in his untrained muscles, coupled with the potential dehydration from the run, contributed to the muscle damage.
2. Diagnostic Test Results:
The diagnostic test results support the diagnosis of rhabdomyolysis:
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Normal Ultrasound: The normal ultrasound rules out deep vein thrombosis (DVT), another possible diagnosis in this scenario.
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Elevated Creatine Kinase (CK): CK is an enzyme found primarily in muscle tissue. When muscle cells are damaged, CK is released into the bloodstream. The patient's CK level of 23,000 U/L is significantly elevated, strongly indicating muscle breakdown.
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Normal BUN and Creatinine: These blood tests assess kidney function. Normal levels rule out acute kidney injury, which can occur as a complication of rhabdomyolysis.
3. Risks Associated with Rhabdomyolysis:
Rhabdomyolysis can lead to several serious complications:
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Acute Kidney Injury (AKI): The breakdown products from damaged muscle, particularly myoglobin, can overwhelm the kidneys, leading to AKI.
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Compartment Syndrome: Swelling in the affected muscle compartment can increase pressure, compromising blood flow and potentially causing tissue damage.
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Electrolyte Imbalances: Rhabdomyolysis can lead to electrolyte imbalances, especially of potassium and calcium, which can affect heart rhythm and muscle function.
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Cardiac Arrhythmias: In severe cases, myoglobin can affect the heart, leading to arrhythmias.
4. Treatment:
Treatment for rhabdomyolysis focuses on:
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Hydration: Intravenous fluids (IV) are essential for flushing out myoglobin and preventing kidney damage.
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Pain Management: Analgesics like ibuprofen may be used to relieve muscle pain. However, NSAIDs (non-steroidal anti-inflammatory drugs) may be contraindicated in severe cases due to potential kidney damage.
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Electrolyte Correction: Electrolyte levels are monitored and corrected as needed.
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Monitoring for Complications: Kidney function, electrolyte levels, and muscle function are carefully monitored for signs of complications.
Additional considerations:
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Lifestyle modifications: Rest, hydration, and appropriate training practices are essential for prevention.
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Prognosis: The prognosis for rhabdomyolysis depends on the severity of the condition and the promptness of treatment. With early diagnosis and appropriate management, most patients make a full recovery.