A case of rhabdomyolysis in the setting of CPT 2 Deficiency

1. Noon Conference
Natalia Filipek, MS3

2. © 2016 Virginia Mason Medical Center 2
Objectives
Rhabdomyolosis
• Clinical Manifestation
• Complications
• Precipitating Factors
• CPT 2 Deficiency
• Diagnosis
• Treatment
• Illness Script

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Clinical Manifestation
Symptoms:
• Triad: muscle pain, weakness, dark urine
• Proximal muscle groups (thighs and shoulders) + lower back and
calves
• Additional sxs: malaise, fever, tachycardia, n/v, abdominal pain
Physical Findings:
• Muscle swelling generally with fluid repletion
• Limb induration
• Overlying skin changes
Laboratory Findings:
• Elevation in CK
• Elevation starting 2 to 12 hrs following onset of muscle injury and reaching max
witihn 24 to 72 hrs
• Elevations in ALT/AST are common
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Clinical Manifestation
Urine Findings:
• Myoglobin released in urine  dark urine
• Both hemoglobin and myoglobin detected as “blood”
on urine dipstick
• Microscopic evaluation  less then 5 RBS per high-powered field
• Proteinuria
Fluid & Electrolyte Abnormalities
• Hypovolemia  third spacing
• Hyperkalemia
• Hyperphosphatemia
• Hypocalcemia
• Ca2+ entering damaged myocytes
• Hyperuricemia
• Release of purines and decreased excretion
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Question
What is the most common late complication of rhabdomyolosis?
A. Disseminated Intravascular coagulation
B. Hepatic Inflammation
C. Acute kidney injury
D. Hyperkalemia
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Common Late Complications
Acute Kidney Injury
• Risk lower in pts with CK levels 15 to 20,000 units/L
• Risk factors:
• Dehydration, sepsis, acidosis
Compartment Syndrome
• Risk lower in pts with CK levels 15 to 20,000 units/L
• Risk factors:
• Dehydration, sepsis, acidosis
Disseminated Intravascular Coagulation
• Infrequent
• Due to release of thromboplastin and from damaged myocytes
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Causes of Rhabdomyolosis
• Traumatic muscle injury
• Increased voluntary or involuntary muscle activity
• Exogenous toxins
• Alcohol, cocaine, polypharmacy (statin + fibrates)
• Infectious etiologies (influenza, HIV, Legionella)
• Neuroleptic Malignant Syndrome
• Genetic causes:
• McArdle’s disease
• Duchenne’s muscle dystrophy
• Carnitine Palmitolytransferase II Deficiency (CPT 2 Deficiency)
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CPT 2 Deficiency
• Disorder of long-chain fatty acid oxidation
• Enzymatic defect that prevents transport into
mitochondria
• 3 clinical presentations
• 1) lethal neonatal form
• 2) severe infantile hepatocardiomuscular form
• 3) myopathic form
– Interferes with iipid metabolism in skeletal muscles
– Triggers: exercise, infection, fasting, cold, general
anesthesia
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Diagnosis
• Creatine kinase
• Urinalysis
• Dark urine
• Other enzyme elevations
• Aldolase, aminotransferase, lactate dehydrogenase
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Question
What is goal urine output in patients being treated for
rhambomyolosis wth IVF?
A. 50-100mL/hr
B. 100-200mL/hr
C. 200-300mL/hr
D. >500mL/hr
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Treatment
Conservative
• Fluid hydration +/- mannitol
• Indications  all patients
Medical
• Sodium bicarbonate
• To alkalinze the urine pH>6.5
• Insulin and glucose
• + calcium gluconate if peaked T-waves
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Illness Script
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Rhabdomyolosis
Pathophysiology
Skeletal muscle injury
Epidemiology
Prevalence in critically ill patients
Alcohol and cocaine induced  80%
Mortality  5%
Time course acute or acute-on-chronic
Clinical
presentation
muscle pain, weakness, dark urine
Diagnostics
Labs: elevated CK, hyperkalemia,
hyperphosphatemia, hypocalcemia
U/A: protein, brown casts, uric acid crystal, red
blood cells, <5RBCs per high power field
Therapeutics Hydration, hydration, hydration!

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Acknowledgements
Dr. Dhami & Dr. Yount
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14. © 2016 Virginia Mason Medical Center
Citations
- https://www.ncbi.nlm.nih.gov/books/NBK1253/
- https://www-uptodate-com.offcampus.lib.washington.edu/contents/clinical-manifestations-
and-diagnosis-of-
rhabdomyolysis?search=rhabdomyolysis&source=search_result&selectedTitle=1~150&usage
_type=default&display_rank=1
- https://www.aafp.org/afp/2002/0301/p907.html
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