Table 4-7.Sources of inhalation poisoning
|Inhalant||Sources of Contact|
|Carbon dioxide||Wells and sewers|
|Carbon monoxide||Fires, lightning, heating and fuel exhausts|
|Carbon tetrachloride||Solvents in dry cleaning fluid, electrical equipment|
|Trichloroethylene||Cleaners, decreasing agents, and fire extinguishers|
|Chemical warfare agents||Tear, nerve, blister, and vomiting gases, screening smokes, thermite and magnesium incendiary substances, hydrocyanic acid, and other systemic poisons|
|Ether, chloroform nitrous oxide, cyclopropane, and freon||Ice making and refrigeration units|
Some substances may cause tissue irritation or destruction by contact with the skin, eyes, and lining of the nose, mouth, and throat. These substances include acids, alkalies, phenols, and some chemical warfare agents. Direct contact with these substances will cause inflammation or chemical burns in the affected areas. Consult the Chemical Burns section of this chapter and the Chemical Agents section of chapter 12 of this manual for treatment.
Injection of venom by stings and bites from various insects, while not normally life-threatening, can cause an acute allergic reaction that can be fatal. Poisons may also be injected by snakes and marine animals.
Stings from bees, wasps, and ants account for more poisonings than stings from any other insect group. Fortunately, they rarely result in death. The vast majority of stings cause a minor local reaction of pain, redness, itching, and swelling at the injection site. These symptoms usually fade after a short time.
A small percent of these stings cause a severe anaphylactic reaction, presenting itching, swelling, weakness, headache, difficulty in breathing, and abdominal cramps. Shock may follow quickly and death may occur. The following first aid measures are recommended:
1. Closely monitor vital signs and remove all rings, bracelets, and watches.
2. Remove stingers by scraping with a dull knife (pulling forces venom remaining in the sac into the wound).
3. Place an ice cube or analgesic-corticosteroid lotion over the wound site to relieve pain.
4. For severe reactions, apply a constricting band above the injured site at the edge of the swelling. Advance it as needed.
5. For severe allergic reactions, immediately give the victim a subcutaneous injection of 1:1000 aqueous solution of epinephrine. Dosage ranges from 0.2 to 0.3 cc for children to 0.5 cc for adults.
6. Patients with severe allergic reactions should be evacuated to a medical facility.
The only North American scorpion of medical importance is the Centruroides sculturatus found in Mexico and certain areas of the American Southwest. Its sting causes severe pain and some weakness in the affected area. It may also cause vomiting, visual disturbances, and circulatory and respiratory depression. In some cases, a state of excitability may occur, with muscle spasms, and in severe cases, progression to a comatose state. The following first aid treatment should be given for scorpion stings:
1. Place ice over the sting site.
2. Morphine and meperidine hydrochloride are contraindicated as they potentate the venom.
3. Calcium gluconate 10 percent may be given intravenously to relieve muscle spasms.
4. Valium maybe used to control excitability and convulsions.