Should LDH (Lactate Dehydrogenase) levels be trended in patients with snake bites?

Monitoring LDH in Snake Bite Patients

LDH should not be routinely trended in snake bite patients as it has no established clinical utility for monitoring envenomation or guiding treatment decisions. 1

Assessment of Snake Bite Patients

• Emergency services should be activated immediately for any person bitten by a venomous or possibly venomous snake 1
• The bitten extremity should be rested and immobilized, and rings or other constricting objects should be removed 1
• Harmful practices to avoid include application of ice, use of suction, electric shock, tourniquets, or pressure immobilization bandaging 1

Recommended Laboratory Monitoring

• Blood chemistry and complete blood count are essential for evaluating snake bite patients 1
• Coagulation studies including prothrombin time (PT/INR), activated partial thromboplastin time (APTT), fibrinogen levels and platelet count should be monitored 1
• Hemoglobin and hematocrit should be measured serially to detect blood loss, though initial values may be normal despite significant bleeding 1
• Blood lactate and/or base deficit measurements are recommended to estimate and monitor the extent of tissue hypoperfusion and shock 1

Why LDH Is Not Recommended for Snake Bite Monitoring

• No snake bite management guidelines from the American Heart Association or other major organizations recommend LDH monitoring for snake bite patients 1
• LDH is a non-specific marker that can be elevated in multiple conditions including liver disease, myocardial infarction, kidney disease, hemolysis, and pneumonia 2
• More specific and clinically relevant laboratory tests are available for monitoring snake bite complications:
  • Coagulation studies directly assess venom-induced consumption coagulopathy 3
  • Renal function tests monitor for acute kidney injury, a common complication 4
  • Hemoglobin/hematocrit and coagulation studies better assess bleeding risk 1

Specific Monitoring Recommendations for Snake Bite Complications

• For hemotoxic venom effects:

  • Monitor PT/INR, APTT, fibrinogen, and platelet count to detect venom-induced consumption coagulopathy 1, 3
  • Serial hemoglobin/hematocrit measurements to detect ongoing bleeding 1
  • Assess for microangiopathic hemolysis with peripheral blood smear 3

• For cardiotoxicity:

  • ECG monitoring for arrhythmias, conduction abnormalities, or ischemic changes 5
  • Cardiac-specific markers (troponin) are more specific than LDH for cardiac damage 5

• For rhabdomyolysis and renal injury:

  • Creatine kinase, myoglobin, and renal function tests are more specific than LDH 4, 6
  • Urinalysis to detect hematuria or proteinuria 4

Clinical Pearls and Pitfalls

• Relying on non-specific markers like LDH may lead to misinterpretation of clinical status and inappropriate management decisions 2
• Initial normal laboratory values do not exclude severe envenomation; serial monitoring is essential 1
• The definitive treatment for venomous snake bite is antivenom, not guided by LDH levels 1
• Focus monitoring on parameters that directly impact clinical decision-making, such as coagulation studies that may indicate need for blood products or antivenom 1, 3