Case Study 6

The Answer

Assessment

  • Patient has a probable snakebite on right forearm with possible envenomation. Based on the MOI there is no spine injury.

The Plan

  • Calm patient.
  • Splint and immobilize right arm at the level of the heart.
  • Monitor for signs of envenomation.
  • Evacuate to definitive care.

Anticipated Problems

  • Increasing pain, bruising and swelling, CSM deficit, and other signs of envenomation.
     

Comments

There are an estimated 7,000 bites by venomous snakes reported in the United States every year. There is a tremendous amount of misinformation, lore, and witchery surrounding diagnosis and treatment. Having the right information about this kind of injury will go far in keeping the patient from the harm that Good Samaritans could otherwise inflict.

Many people, including this patient, believe a pit viper bite to be lethal. In fact, of the 7,000-8,000 bites reported yearly in the U.S. only five or six result in death. Death tends to occur in children, the elderly, and those that have delay in antivenin treatment.

People assume that any bite from a pit viper results in envenomation; however, data suggests that envenomation from the pit viper is not automatic from every strike. Although exact numbers are hard to find, an estimated 30% -50% of reported snake bites are “dry” bites and do not result in envenomation.

Thus an important part of your care may be to calm and reassure the patient. His initial pale, clammy skin and elevated heart rate are likely a stress reaction. To see these abate over time is encouraging.

You’ll also need to watch for signs of envenomation. These include swelling, bruising, and local pain. Not seeing these in the first 30 minutes to an hour is a good sign that there was minimal or no envenomation. You might also see formation of blisters and the patient may sweat and complain of chills, weakness, and nausea. They may vomit. Severe envenomation can present with signs and symptoms of shock.

When envenomation does occur there are a number of techniques erroneously believed to be effective. These range from electric shock to tourniquets to cutting and sucking and other odd remedies. These techniques have been shown to lack effectiveness when studied in a clinical setting.

Signs and symptoms of envenomation may not present early. Some snakes, such as the coral snake, are known to make you sick 12 or more hours after the bite. Waiting for s/s of envenomation may delay access to anti-venom, thus we recommend that all snake bite patients be evacuated, and those with s/s of envenomation be rapidly evacuated.

What we know to be effective is calming the patient, immobilization of the limb, and once definitive care is reached, anti-venom therapy as necessary. Calming the patient can be the most challenging aspect of treatment. Knowing what is and isn’t true of pit viper bites will go a long way in caring for your patient.

End of the Tale

With much convincing you are able to assuage your patient’s worst fears of death or of losing his limb. You immobilize the arm with a sling and swathe and walk five minutes back on the trail to the two-track road. From there you get your truck to the patient and you head to town and a rendezvous with the local EMS unit.

On the way to the car you meet a young man with several medical and rescue patches who offers to pull the venom out by applying mechanical suction through a commercially made unit. Citing a recently published peer-reviewed article describing the lack of effectiveness of this technique you politely decline this offer of help and continue on your way. Nor do you accept his offer to cut your patient and draw the venom from the wound with suction applied orally.

When you reach your vehicle you find one final obstacle between you and your patient's best interests, a well-intentioned bystander who offers jumper cables and a car battery to render the venom impotent. This too is calmly avoided.

On your way to the hospital there is noticeable increase in swelling. Your patient also reports an increase in pain locally, but his vital signs remain stable. By the time the hospital is reached your patient has a tingling sensation throughout his arm and there is bruise-like tissue surrounding the punctures.

He is evaluated in the emergency room and given anti-venom treatment. After several days it is clear he will make a full recovery with no side effects.