Is CK 876 safe for DC?

Safety of CK 876 for Discharge

A creatine kinase (CK) level of 876 is generally safe for discharge if there are no other concerning clinical findings or risk factors.

Understanding CK Elevation

CK is an enzyme found primarily in skeletal muscle, cardiac muscle, and brain tissue. Elevated levels can indicate muscle damage from various causes:

• Normal range typically varies by laboratory but is generally 30-200 U/L for men and 20-180 U/L for women
• CK elevation can occur from:
  • Exercise/physical exertion
  • Muscle trauma
  • Medications (statins, etc.)
  • Intramuscular injections
  • Inflammatory myopathies
  • Cardiac events

Clinical Decision Making for CK 876

Assessment Framework

1. Determine if CK elevation is clinically significant

   • A CK of 876 represents a mild to moderate elevation
   • According to guidelines, concerning thresholds are 1:
     • Worrisome level: >10 times upper limit of normal
     • For reference, rhabdomyolysis is typically diagnosed at >10,000 U/L

2. Evaluate for cardiac involvement

   • If concerned about cardiac origin, assess CK-MB/CK ratio
   • Ratio >5-6% suggests cardiac involvement 2
   • Consider troponin testing which is more specific for cardiac injury 1

3. Consider context of elevation

   • Recent exercise can cause CK elevations up to 6420% above baseline without renal impairment 3
   • Obesity may be associated with higher baseline CK levels 4

Decision Algorithm

1. Check for red flags that would require admission:

   • Renal dysfunction (elevated creatinine, BUN)
   • Electrolyte abnormalities (particularly potassium)
   • Signs of compartment syndrome
   • Significant muscle weakness or pain
   • Dark urine suggesting myoglobinuria
   • Cardiac symptoms or ECG changes

2. If no red flags are present:

   • Patient is safe for discharge with appropriate follow-up
   • Consider repeat CK in 48-72 hours if clinically indicated
   • Recommend adequate hydration

Special Considerations

Cardiac Evaluation

• If cardiac cause is suspected, follow ACS guidelines 1
• CK-MB has largely been replaced by troponin for cardiac evaluation 1
• Consider delta measurements if serial testing is performed 1

Medication-Related Elevations

• If patient is on statins, follow guidelines for monitoring 1:
  • Temporarily withhold medication if symptoms present
  • Resume when abnormalities return to normal
  • Monitor CK every 3-6 months

Exercise-Induced Elevations

• Research shows healthy individuals can have marked CK elevations (>10,000 U/L) after eccentric exercise without renal impairment 3
• Context of recent exercise is important in interpreting values

Conclusion

A CK of 876 is a relatively modest elevation that, in the absence of other concerning findings, does not warrant hospital admission. Ensure adequate hydration, identify and address any underlying causes, and consider follow-up testing if symptoms persist or worsen.