What is the treatment for a common sea snake bite?

Treatment for Common Sea Snake Bite

Immediately activate emergency services and transport the patient to a hospital for antivenom administration, as sea snake venom is highly neurotoxic and can cause respiratory paralysis within hours—pressure immobilization bandaging should be applied to the entire bitten extremity to slow lymphatic spread of venom. 1

Immediate Field Management

Critical First Actions

• Apply pressure immobilization bandaging with 40-70 mm Hg pressure in the upper extremity or 55-70 mm Hg in the lower extremity around the entire length of the bitten limb, as this effectively slows venom dissemination by restricting lymphatic flow without worsening tissue injury (unlike pit viper bites where this technique is contraindicated). 1
• Activate emergency medical services immediately, as definitive treatment requires antivenom that is only available in hospital settings. 1
• Completely immobilize the bitten extremity and keep it below heart level to minimize venom absorption through the lymphatic system. 1
• Remove all rings, watches, and constricting jewelry before swelling develops, as edema can cause ischemic injury to digits. 1
• Minimize patient exertion during transport—walking or physical activity increases systemic venom absorption. 1

What NOT to Do (Potentially Harmful)

• Do not apply ice or cold therapy—this is ineffective for venom removal and can cause tissue injury. 1
• Do not use suction devices, incision, or mouth suction—these methods are ineffective at removing venom and may cause additional tissue damage. 1
• Do not apply tourniquets—systematic reviews show they worsen local tissue injury without preventing systemic envenomation. 1
• Do not use electric shock therapy—this is both ineffective and potentially harmful. 1

Clinical Presentation and Monitoring

Neurotoxic Syndrome Recognition

• Sea snake venom is predominantly neurotoxic and myotoxic, causing progressive paralysis with minimal to no local tissue injury at the bite site. 2
• The absence of pain or swelling does NOT rule out serious envenomation—this is a critical pitfall, as sea snakes cause life-threatening systemic toxicity despite minimal local findings. 3, 4
• Monitor continuously for signs of neurotoxicity: muscle weakness, ptosis, difficulty swallowing, respiratory distress, or altered mental status. 3, 5
• Neurotoxicity onset can occur within minutes but may be delayed up to several hours, requiring prolonged observation. 3, 4

Myotoxic Effects

• Myotoxicity can cause rhabdomyolysis with subsequent renal failure—monitor for dark urine and muscle pain. 2
• Hemodialysis may be necessary when renal complications develop, particularly if antivenom is unavailable. 2

Hospital-Based Definitive Treatment

Antivenom Administration

• Administer sea snake antivenom to all patients with confirmed or suspected sea snake envenomation showing any signs of neurotoxicity or myotoxicity. 3, 2
• Sea snake antivenom is the only definitive treatment and can be lifesaving when administered promptly. 2
• Be prepared to manage hypersensitivity reactions, as equine-derived antivenoms commonly cause acute anaphylactic reactions (usually within the first hour) or delayed serum sickness (5-14 days post-administration). 6

Supportive Care

• Provide respiratory support including mechanical ventilation if respiratory paralysis develops—patients may require artificial ventilation for extended periods (up to 22 hours documented). 5
• Monitor and maintain airway, breathing, blood pressure, heart rate, renal function, fluid balance, and coagulation status continuously. 7
• Hospitalize for a minimum of 48 hours with continuous monitoring, as neurotoxicity onset can be delayed and progression is rapid once symptoms begin. 3

Key Clinical Distinctions

Sea snakes differ fundamentally from North American pit vipers and coral snakes:

• Unlike pit vipers (>95% of North American bites), sea snake venom does not cause significant local tissue destruction, making pressure immobilization safe and effective. 1, 2
• Similar to coral snakes in neurotoxic effects, but sea snakes also have significant myotoxic components causing rhabdomyolysis. 2, 7
• The 2024 American Heart Association guidelines specifically note that snakes in other parts of the world (including sea snakes) have different venom effects requiring different first aid measures than North American species. 1

Critical Pitfalls to Avoid

• Assuming no envenomation based on lack of local symptoms is dangerous—sea snakes cause minimal local findings despite life-threatening systemic toxicity. 3, 2
• Delaying transport to attempt ineffective field interventions wastes critical time—time to antivenom is the most important prognostic factor. 3
• Premature discharge can be fatal—neurotoxicity can be delayed up to 13 hours, and respiratory paralysis can develop rapidly once symptoms begin. 3, 5
• Failing to apply pressure immobilization for sea snakes (unlike North American snakes) eliminates the most effective pre-hospital intervention for slowing venom spread. 1