If a tourniquet has been applied, it should not be removed until antivenom is at hand and the means for treating complications, including possible complications caused by the antivenom, are available.

One case was reported in which a Hydrophiidae bite led to neurological symptoms and subsequent respiratory insufficiency after cessation of stasis in the lower leg, even though the child, who had been bitten by an Astrotia stokesii (=Hydrophis stokesii), was previously asymptomatic (Mercer et al. 1981).

The symptoms and degree of envenoming depend not only on the amount of venom injected and numerous other variables, but also on the time that has elapsed since the bite. This variable factor must be taken into account when making the following decisions:

• exclusion of envenoming,
• the time interval between clinical examinations,
• emergency care.

The fact that a patient has been bitten by a sea snake and the presence of bite marks do not automatically allow the conclusion that a clinically relevant injection of venom has taken place [39 of 55 Enhydrina schistosa (=Hydrophis schistosus) bites, 11/14 Hydrophis cyanocinctus bites and 6/9 Hydrophis spiralis bites did not involve a clinically relevant injection of venom (Reid 1975b)].

Local signs, such as swelling and pain at the site of the bite, are usually absent and thus completely unreliable as clinical indicators of an injection of venom.

There seem to exist 2 forms of Hydrophiidae envenoming with different courses:

1. primarily myotoxic envenoming (e.g. Enhydrina schistosa): signs and symptoms arising in the skeletal musculature; secondary effects of rhabdomyolysis: dark urine (myoglobinuria), acute renal failure, cardiac dysrhythmias (hyperkalaemia);
2. neurotoxic/(myotoxic) envenoming (e.g. Astrotia stokesii): initially prominent are acute neurotoxic symptoms that occur a short time after the bite and their corresponding signs: ptosis, ophthalmoplegia, dysphagia, dysphonia; progressive paralysis of the respiratory musculature with respiratory insufficiency and failure.

According to observations by Reid in Penang (Malaysia) severe envenoming can be excluded if there is no skeletal muscle pain upon movement 2 h after the bite (Reid 1979). However, these observations were made chiefly in patients who had been bitten by Enhydrina schistosa.

Symptomatic emergency medical treatment and antivenom treatment are complementary strategies.

The aim of antivenom treatment is neutralisation of the venom.

The success of antivenom treatment depends on the quality of the antivenom, the specific properties of those venom components relevant to envenoming and the time point at which antivenom is administered.

Symptomatic emergency medical treatment and antivenom treatment are complementary strategies.

The aim of symptomatic emergency medical treatment is the rapid correction of critical parameters (fluid balance, blood pressure, oxygenation etc.) and the maintenance of vital functions (respiratory, cardiovascular).

Symptomatic measures help bridge the gap until specific treatment (antivenom) can be administered and starts being effective. If no antivenom is available or if the required effect is not achieved with antivenom, the goal is to employ symptomatic measures until such time as the venom naturally starts losing its activity. 

Neostigmine appears to have been ineffective in the cases observed by Reid (1956, 1961a).

However, this does not exclude the possibility that it could be effective in those cases of Hydrophiidae envenoming in which the neurological effects of the venom are prominent (e.g. Astrotia stokesii).

• Cleaning, disinfection and dressing of the wound at regular intervals.
• Immobilisation of the extremity with a splint.
• Possibly also prophylactic antibiotic treatment.