Rhabdomyolysis-

Clinical Presentation example:

An 18-year-old marathon runner has been training during the summer. He is brought to the emergency room disoriented after collapsing on the track. His temperature is 102°F. A Foley catheter is placed and reveals reddish urine with 3+ blood on the dipstick and no cells are seen microscopically. Which of the following is the most likely explanation for his urine?

1. Underlying renal disease
2. Prerenal azotemia
3. Myoglobinuria
4. Glomerulonephritis

Pathophysiology

Rhabdomyolysis is a syndrome that is caused by injury to skeletal muscle fibers which cause the intracellular content to leak into the circulation. Most common intracellular contents that are released into the circulation:

• Myoglobin
• CK
• Aldolase
• Lactate dehydrogenase
• Aspartate aminotransferase
• Potassium

Most Common Causes:

Drugs of abuse and alcohol, Medications, muscle diseases, trauma, neuroleptic malignant syndrome, Seizures, Infection, strenuous physical activity, heat-related illness.

Presenting symptoms

• Myalgias
• stiffness
• Weakness
• Malaise
• Low-grade fever
• Dark (usually brown) urine
• In severe cases: nausea, vomiting, abdominal pain, & tachycardia may occur

Laboratory Finding:

• An elevated serum creatine kinaseis the most sensitive and reliable indicator of muscle injury. If the serum creatine Kinase is five fold greater than normal level than in in the absence of cardiac or brain injury then it can be consider as Rhabdomyolysis.
• Positive urinary dipstick for “blood” (actually myoglobin) in the absence of red cells in the sediment
• Elevated serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LD)
• Hyperkalemia
• Hypocalcemia

Treatments

• The mainstay of treatment is IV rehydration with normal saline for the next 24 to 72 hours. vigorous IV fluid resuscitation is the most important treatment in preventing acute renal failure.
• Urine alkalinization to reduce kidney injury

Common complications:

• Acute renal failure
• Metabolic derangement
• DIC
• Mechanical complications (e.g. compartment syndrome, peripheral neuropathy)

 

Answer to the clinical presentation case:

1. Myoglobinuria.

Explanation: Rhabdomyolysis causes to release of myoglobin which can leads to a reddish appearance and positive urine dipstick reaction for blood, but microscopic analysis of the urine likely will demonstrate no red cells.

Sources:

1. “Rhabdomyolysis.” Quick Medical Diagnosis & Treatment 2020 Eds. Maxine A. Papadakis, et al. New York, NY: McGraw Hill, http://accessmedicine.mhmedical.com.york.ezproxy.cuny.edu/content.aspx?bookid=2750&sectionid=231379672.
2. Hellmann, David B., and John B. Imboden Jr.. “Rhabdomyolysis.” Current Medical Diagnosis and Treatment 2020 Eds. Maxine A. Papadakis, et al. New York, NY: McGraw-Hill, , http://accessmedicine.mhmedical.com.york.ezproxy.cuny.edu/content.aspx?bookid=2683&sectionid=225052785.
3. Counselman, Francis L.. “Rhabdomyolysis.” Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e Eds. Judith E. Tintinalli, et al. New York, NY: McGraw-Hill, , http://accessmedicine.mhmedical.com.york.ezproxy.cuny.edu/content.aspx?bookid=2353&sectionid=204498760.
4. https://drhussain89.files.wordpress.com/2016/05/case-files-internal-medicine.pdf