Sea Snake Envenomation Treatment & Management

The critical components of prehospital care for sea snake bites are initial stabilization with airway control, pressure immobilization of the bitten extremity, and prompt transport to a facility capable of providing advanced medical care (including antivenom administration).

• A brief attempt to visually identify the offending snake is warranted, but prolonged attempts to kill or capture the snake should be avoided. The bite reflex persists for up to an hour even after the snake is decapitated, making it possible for dead snakes to inflict a serious bite.
• If needed, institute supportive measures, including endotracheal intubation and mechanical ventilation, as clinically indicated.
• Apply pressure immobilization of the bitten extremity as quickly as possible because it may impede venom spread. Rapidly wrap the limb with a broad pressure bandage, starting at the wound site and extending as high up the extremity as possible. The bandage should be wrapped to venous occlusive pressure (approximately 70 mm Hg) in a manner similar to wrapping a sprained ankle. An extremity splint completes the immobilization. See the images below. Technique for application of pressure immobilization in field management of sea snake bites. Figure 1, Apply a broad-pressure bandage over the bite site as soon as possible. Do not take off jeans because the movement of doing so assists venom to enter the bloodstream. Keep the bitten leg still. Figure 2, The bandage should be as tight as would be applied to a sprained ankle. Figure 3, Extend the bandage as high as possible. Technique for application of pressure immobilization in field management of sea snake bites. Figure 4, Apply a splint to the leg. Figure 5, Bind the splint firmly to as much of the leg as possible. If the bandages and splint are applied correctly, they will be comfortable and may be left on for several hours. They should not be taken off until the patient has reached medical care. The doctor will decide when to remove the bandages. If venom has been injected, it will move into the bloodstream quickly once the bandages are removed. The doctor should leave the bandages and splint in position until he or she has assembled appropriate antivenom and drugs that may need to be used when the dressings and splint are removed. Figure 6, For bites on a hand or forearm, bind to the elbow with bandages, use a splint to the elbow, and use a sling.
• Avoid incision, ice, or other cooling measures.
• Suction is unlikely to be beneficial and only should be attempted if a mechanical suction device is immediately available.

• Stabilization of airway, breathing, and circulation (ABCs)
• Intravenous access
• Cardiac monitoring and continuous pulse oximetry
• Tetanus prophylaxis

Antivenom administration

Antivenom administration is indicated for any patient with signs of envenomation. The agent of choice is polyvalent sea snake antivenom (Commonwealth Serum Laboratories, Melbourne, Australia). Alternatively, tiger snake (Notechis scutatus) antivenom can be substituted because of the close relationship of tiger snake and sea snake venoms.

Indications for antivenom use include shock, respiratory distress or failure, generalized myalgias, trismus, moderate-to-severe pain with passive movement of extremities, myoglobinuria, elevated creatine kinase level (>600 IU/l), altered level of consciousness, hyperkalemia, or leukocytosis.

Administer antivenom as soon as possible. Benefits may be observed up to 36 hours after the bite.

For early mild-to-moderate envenomation, use one ampule of antivenom (1000 U). Later or severe envenomation typically requires 3-10 ampules (3000-10,000 U) of antivenom, respectively.

If antivenom is not available, consider dialysis. Sea snake neurotoxin is of low enough molecular weight to be dialyzable. Furthermore, dialysis may be life saving in cases of severe hyperkalemia.

Aggressive hydration with diuresis can help promote renal myoglobin clearance. Urine alkalinization may be of some benefit in cases of myoglobinuria.

In-patient admission for observation, especially if the patient is to receive antivenom as allergic/anaphylactic reactions are common.

• Poison control centers, zoos, or experts in snake envenomation may help guide the management of sea snake envenomations and assist with the location of antivenom.
• In cases of serious envenomation, an internist or intensivist should be consulted for admission to the hospital or intensive care unit, respectively.