Treatment Algorithm®

1

ASSESS PATIENT

  • Mark leading edge of swelling and tenderness every 15-30 minutes
  • Immobilize and elevate extremity
  • Treat pain (IV opioids preferred)
  • Obtain initial lab studies (protime, Hgb, platelets, fibrinogen)
  • Update tetanus vaccine
  • Contact poison control center (1-800-222-1222)
2

Check for Signs of Envenomation

  • Swelling, tenderness, redness, ecchymosis, or blebs at the bite site, or
  • Elevated protime; decreased fibrinogen or platelets, or
  • Systemic signs, such as hypotension, bleeding beyond the puncture site, refractory vomiting, diarrhea, angioedema, neurotoxicity
9

Apparent Dry Bite / No Bite

  • Do not administer CroFab®
  • Observe patient ≥8 hours
  • Repeat labs prior to discharge
  • If patient develops signs of envenomation, return to Box 2
3

Check for Progression of Clinical Effects

  • Swelling that is more than minimal and that is progressing, or
  • Elevated protime; decreased fibrinogen or platelets, or
  • Any systemic signs
10

APPARENT MINOR ENVENOMATION

  • Do not administer CroFab®
  • Observe patient 12-24 hours
  • Repeat labs at 4-6 hours and prior to discharge
  • If patient develops progression of any signs of envenomation, return to Box 3
4

ADMINISTER CROFAB®

  • Establish IV access and give IV fluids
  • Pediatric CroFab® dose = adult dose
  • Mix 4-6 vials of CroFab® in 250 ml NS and infuse IV over 1 hour - For patients in shock or with serious active bleeding call physician-expert (see box 12)
  • Initiate first dose of CroFab® in ED or ICU - For suspected adverse reaction: hold infusion, treat accordingly, and call physician-expert
  • Re-examine patient for treatment response within 1 hour of completion of CroFab® infusion
5

DETERMINE IF INITIAL CONTROL OF ENVENOMATION HAS BEEN ACHIEVED

  • Swelling and tenderness not progressing
  • Protime, fibrinogen, and platelets normal or clearly improving
  • Clinically stable (not hypotensive, etc.)
  • Neurotoxicity resolved or clearly improving
11

REPEAT CROFAB® UNTIL INITIAL CONTROL IS ACHIEVED

  • If initial control is not achieved after 2 doses of CroFab®, call physician-expert Box 12
6

MONITOR PATIENT

  • Perform serial examinations
  • Maintenance CroFab® therapy may be indicated
    • Read box 13 (Maintenance CroFab® Therapy)
  • Observe patient 18-24 hours after initial control for progression of any venom effect
  • Follow-up labs 6-12 hours after initial control and prior to discharge
  • If patient develops new or worsening signs of envenomation, administer additional doses of CroFab® per box 4
7

DETERMINE IF PATIENT MEETS DISCHARGE CRITERIA

  • No progression of any venom effect during the specified observation period
  • No unfavorable laboratory trends in protime, fibrinogen, or platelets
8
  • SEE POST-DISCHARGE PLANNING ( Box 14 )

12a

WHEN TO CALL A PHYSICIAN-EXPERT

Direct consultation with a physician-expert is recommended in certain high-risk clinical situations:
  • Life-threatening envenomation
    - Shock - Serious active bleeding - Facial or airway swelling
  • Hard-to-control envenomation
    Envenomation that requires more than 2 doses of CroFab® for initial control
  • Recurrence or delayed onset of venom effects
    Worsening swelling or abnormal labs (protime, fibrinogen, platelets, or hemoglobin) on follow-up visits
12b

WHEN TO CALL A PHYSICIAN-EXPERT

  • Complicated wound issues
  • Allergic reactions to CroFab®
  • If transfusion is considered
  • Complicated wound issues
  • Uncommon clinical situations
    - Bites to the head and neck - Rhabdomyolysis - Suspected compartment syndrome - Venom-induced hives and angioedema
If no local expert is available, a physician‐expert can be reached through a certified poison center (1-800-222-1222) or the CroFab® manufacturer’s line (1-877-377-3784).
13

MAINTENANCE CROFAB® THERAPY

  • Maintenance therapy is additional CroFab® given after initial control to prevent recurrence of limb swelling - Maintenance therapy is 2 vials of CroFab® Q6H x 3 (given 6, 12, and 18 hours after initial control)
  • Maintenance therapy may not be indicated in certain situations, such as: - Minor envenomations - Facilities where close observation by a physician-expert is available
  • Follow local protocol or contact a poison center or physician-expert for advice
14a

POST-DISCHARGE PLANNING

  • Instruct patient to return for:
    • Worsening swelling that is not relieved by elevation
    • Abnormal bleeding (gums, easy bruising, melena, etc.)
  • Instruct patient where to seek care if symptoms of serum sickness (fever, rash, muscle/joint pains) develop
14b

POST-DISCHARGE PLANNING

  • Bleeding precautions (no contact sports, elective surgery, or dental work, etc.) for 2 weeks in patients with:
    • Rattlesnake envenomation
    • Abnormal protime, fibrinogen, or platelet count at any time
  • Follow-up visits
    • CroFab® not given - PRN only
    • CroFab® given - Copperhead victims: PRN only - Other snakes: Follow up with labs (protime, fibrinogen, platelets, hemoglobin) twice (2-3 days and 5-7 days), then PRN
15

TREATMENTS NOT PROVEN TO BE BENEFICIAL IN THE MANAGEMENT OF PIT VIPER ENVENOMATION

  • Cutting and/or suctioning of the wound
  • Ice
  • NSAIDs
  • Prophylactic antibiotics
  • Prophylactic fasciotomy
  • Routine use of blood products
  • Shock therapy (electricity)
  • Steroids (except for allergic phenomena)
  • Tourniquets
16

NOTES

  • This information is adapted from general advice from a panel of US snakebite experts convened in May 2010. No algorithm can anticipate all clinical situations. Other valid approaches exist, and deviations from this information based on individual patient needs, local resources, local treatment guidelines, and patient preferences are expected.

    This website is not intended to represent a standard of care. For more information, please see the accompanying manuscript, available at www.biomedcentral.com.
  • FULLTREATMENT ALGORITHM
  • The algorithm is also available in PDF format, so it can be accessed here for viewing or downloaded for future reference.