Cobra Envenomation Follow-up
- Author: Robert L Norris, MD; Chief Editor: Joe Alcock, MD, MS more...
Further Outpatient Care
Patients with necrosis need continued outpatient management of their wounds and should be warned about the signs and symptoms of infection. Continued outpatient physical therapy may be necessary.
Patients who received antivenom should be aware of the signs and symptoms of delayed serum sickness and should return if they develop.
Patients who have experienced acute ophthalmia following spitting cobra venom exposure should have outpatient ophthalmologic follow-up to monitor for complications such as uveitis or corneal ulceration.
Further Inpatient Care
Admit all cobra snakebite patients to closely monitored settings, whether or not antivenom is given.
Observe asymptomatic patients for at least 24 hours. Delayed signs and symptoms may occur.
If signs or symptoms of envenomation progress after first administration of antivenom, a second dose of antivenom may be required. If two doses of antivenom are given and the victim still requires airway intubation and ventilatory support, further antivenom administration will be unhelpful.
Continue to administer epinephrine, antihistamines, and steroids to a patient experiencing an acute allergic reaction to antivenom until the patient is stable.
If necrosis occurs, initiate standard, conservative wound care (eg, cleansing, splinting, debridement as necessary). Secondary bacterial infections may occur and are usually caused by gram-negative bacilli, such as Proteus, Pseudomonas, and Enterobacter species. Initial antibiotics should cover gram-positive and gram-negative organisms. Culture results should determine use of further antibiotics. Occasionally, debridement, amputation, or grafting of tissue is required.
Warn patients who have received antivenom about the signs and symptoms of delayed serum sickness. If these signs or symptoms develop after discharge, evaluate the patient promptly for initiation of systemic steroids and diphenhydramine as outlined above.
People bitten by cobras should be cared for in a facility capable of intensive monitoring.
Professional snake keepers should use standard safety techniques (eg, locked cages, trap boxes, protective eyewear) when dealing with cobras and other species that spit venom.
Amateurs should refrain from keeping exotic venomous snakes in their collections. If they keep such snakes, they should know the specific species they keep, the appropriate antivenom type, and where it can be obtained in an emergency. Preferably, amateurs should maintain their own supply of appropriate antivenom, but this may be difficult (due to regulations related to importing foreign antivenoms into the country) and expensive.
Travelers in regions where cobras are indigenous should wear protective clothing (long pants and footwear), avoid areas where snakes seek cover, and know the location of the nearest source of medical care in case they are bitten.
Complications of cobra envenomation may include the following:
Prolonged neuromuscular weakness
Antivenom-related complications - Nonallergic anaphylactic (anaphylactoid) reactions, delayed serum sickness
Venom-induced ophthalmia (spitting cobras)
Many patients recover with no specific treatment.
The neurotoxic effects of cobra venom are completely reversible, though recovery may take up to 6 days.
Reports of death within 1 hour of cobra bite exist, but a timeframe of 2-6 hours is more typical of fatal cases.
With sound supportive care (eg, prevention of aspiration and respiratory support) and appropriate, prompt antivenom administration, anticipate recovery from cobra envenomation.
Advise amateur herpetoculturists bitten by a venomous snake in their collection to not keep such animals. If they previously have received antivenom, their risk for an allergic reaction may be increased should antivenom use be required again in the future.
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