​A​ snake bite presenting to general practitioners could be an emergency requiring immediate attention and ambulance conveyance to the nearest emergency department. Through a clinical case study, Changi General Hospital shares helpful resources and tips on how to manage such cases in the primary care setting – including checking for envenomation, wound care and immobilisation.

CASE STUDY

A 34-year-old male presented to the Changi General Hospital (CGH) emergency department (ED) with a snake bite in the anterior leg acquired while on a boat (Figure 1). He came to the hospital by his own transport within two hours.

Clinically, the patient had normal vital signs with no systemic and local signs to suggest envenomation. A picture taken of the snake using a mobile device was shared by the patient (Figure 2).

This was sent by instant messaging to ACRES (Animal Concerns Research and Education Society), which identified the snake as a non-venomous red-tailed racer (gonyosoma oxycephalum). The patient was discharged uneventfully from the ED after 13 hours of observation.

Snake bite - CGH

Figure 1 Snake bite

 

Figure 2 Red-tailed racer (gonyosoma oxycephalum)

RESOURCES FOR SNAKE IDENTIFICATION

In Singapore, we have found the following resources useful at helping to identify snakes:

  • ACRES Wildlife Rescue Centre1
    • Call 9783 7782 (operates 24/7)
  • National Parks Board / Animal & Veterinary Service2

In this case, the immediate assistance from ACRES via WhatsApp helped to reassure the patient and develop the management plan early. The availability of such resources should not delay the management of emergencies, or immediate transfer of patients by ambulance to the hospital.

Digital pictures should be taken from a safe distance and show the whole snake.

HOW TO MANAGE SNAKEBITE VICTIMS IN PRIMARY CARE

The following areas are important while attending to a snakebite victim:

1. General Points and Transportation

Resuscitation

  • As necessary when there is haemodynamic compromise, anaphylaxis (drug of choice: intramuscular adrenaline)

Reassurance

  • Calming the patient helps to reduce anxiety, slow down the heart rate and reduce the systemic effects of the toxin

Pain Control

  • Non-sedating analgesia

Tetanus toxoid

  • Optional
  • Should not delay transportation

Antibiotics

  • Usually not necessary unless there is infection

Ambulance conveyance to the nearest ED

  • When in doubt, assume that the snake is venomous and send the patient to hospital by emergency ambulance
  • Avoid physical activity and movement of the affected limb, (e.g., do not walk or cycle to the hospital)

2. Check for Envenomation

Systemic

  • Haemodynamic instability (tachycardia, hypotension)
  • Tachypnoea
  • Sweatiness
  • Salivation
  • Muscle weakness

Local

  • Tenderness
  • Swelling
  • Bleeding
  • Ecchymosis
  • Blistering

Note: Anti-snake venom (ASV) should be given only at the ED or where resources to manage anaphylaxis are immediately available.3

3. Wound Care

Mark the leading edge of the skin swelling4

  • Marking allows monitoring of the swelling

Cover the wound with a dressing

  • Avoid pressing the wound
  • Avoid irrigating the wound or washing and rubbing the bitten area because that encourages local and systemic spread of venom5

Note: Do not attempt to cut the wound or suck the venom, because there is no proven benefit3 and it increases the possibility of infection.

4. Immobilisation

Immobilise the bitten limb

  • E.g., upper limb splinting and broad arm sling

Pressure immobilisation bandage

  • Applied around the entire length of the bitten extremity with the aim of decreasing venom dissemination by slowing lymph flow (only to be applied by trained individuals)
  • May increase local toxicity for venoms that destroy tissue at the site of the bite6
  • The correct amount of pressure needs to be applied to halt lymph flow, yet maintaining blood circulation

5. Snake Identification

Do not handle the snake (if it is brought to the clinic)

  • Call for trained wildlife rescue personnel
  • Severed snake heads can still bite!

Digital picture of snake

  • Resources mentioned above may assist to identify the snake

 

CONCLUSION

In conclusion, there are useful resources in Singapore to help identify and remove snakes. When in doubt, it is safer to assume envenomation after a snake bite and convey the victim to the ED without delay.

Marking the leading edge of skin swelling will help subsequent providers monitor progress of the condition, and good prehospital management will aid to improve outcomes.

REFERENCES

  1. Animal Concerns Research and Education Society. ACRES Advisory Notice: Snakes [online]. Available at: https://acres.org.sg/core/wp-content/uploads/2017/01/ACRES-Advisory-on-Snakes.pdf. Accessed 27 Sep 2021.

  2. National Parks. Snakes [online]. 5 Feb 2021. Available at: https://www.nparks.gov.sg/gardens-parks-and-nature/dos-and-donts/animal-advisories/snakes. Accessed 27 Sep 2021.

  3. Weinstein S, Dart R, Staples A, White J. Envenomations: an overview of clinical toxinology for the primary care physician. American family physician 2009; 80:793-802.

  4. Ashurst J, Cannon R. Approach and management of venomous snake bites: a guide for the primary care physician. Osteopathic Family Physician 2012; 4:155-159.

  5. Zarisfi F, Pek JH, Oh JHH, Loke JH, Lim SH. Singapore First Aid Guidelines 2021. Singapore Med J. 2021; 62(8):427-432.

  6. Parker-Cote J, Meggs WJ. First aid and pre-hospital management of venomous snakebites. Tropical medicine and infectious disease 2018; 3(2): 45.