Poisoning and Drug Overdose Management

Poisoning and Drug Overdose

• Poisoning and drug overdoses can cause rapid physical and mental changes in a person.
• Bystanders usually initiate care and call a poison control center or emergency number.

Routes of Exposure

• The most common routes of exposure in poisoning are inhalation, ingestion, and injection.
• Toxic chemical reactions can compromise cardiovascular, respiratory, central nervous, hepatic, gastrointestinal (GI), and renal systems.

Poisoning at Home

• Most exposures to toxic fumes occur in the home.
• Poisoning may result from the improper mixing of household cleaning products or malfunctioning household appliances that release carbon monoxide.
• Carbon monoxide gas is colorless, odorless, tasteless, and non-irritating, which makes it especially dangerous.

Substance Abuse and Overdose

• Most poisoned patients are admitted to a critical care unit for an intentional or suspected suicidal overdose.
• These patients frequently have histories of mental illness, substance abuse problems, or both.
• Commonly abused substances include nicotine, alcohol, heroin, marijuana, narcotic analgesics, amphetamines, benzodiazepines, and cocaine.

Assessment

• Goals of immediate treatment are patient stabilization and evaluation and management of airway, breathing, and circulation.
• History identifies the drugs or toxins, the time and duration of the exposure, first aid treatment given before arrival at the hospital, allergies, and any underlying disease processes or related injuries.
• Physical examination involves a toxidrome, a group of signs and symptoms associated with overdose or exposure to a particular category of drugs and toxins.
• Laboratory studies include electrolytes, hepatic function, urinalysis, electrocardiography, and serum osmolality tests.

Management

• Prevent absorption of and further exposure to the agent.
• Advanced general management involves further steps to prevent absorption and enhance elimination of the agent.
• Antidotes, antivenins, or antitoxins, when available, may be administered.
• Support vital functions and monitor and treat multisystem effects.

Stabilization

• Airway patency
• Breathing
• Circulation
• Cardiac function
• Acid–base balance and electrolyte homeostasis
• Mentation
• Injuries associated with toxic exposure and underlying disease processes
• Vital signs and temperature

Initial Decontamination

• First aid may be given by a bystander, health care provider, or emergency response team or in the emergency department.
• Decontamination methods for ocular, dermal, inhalation, and ingestion exposures follow:
  • Ocular exposure: flush to remove the agent
  • Dermal exposure: flood the skin with lukewarm water for 15 to 30 minutes
  • Inhalation exposure: move to fresh air as quickly as possible
  • Ingestion exposure: milk or water dilutes ingested irritants, such as bleach, or caustics, such as drain cleaner

Gastrointestinal Decontamination

• To prevent absorption of, and forestall toxicity from, almost all drugs and a variety of toxins, the following may be used:
  • Gastric lavage
  • Adsorbents
  • Cathartics
  • Whole-bowel irrigation

Enhanced Elimination of the Drug or Toxin

• Multiple-dose activated charcoal
• Alteration of urine pH
• Hemodialysis
• Hyperbaric oxygenation therapy

Antagonists, Antitoxins, and Antivenins

• Antagonist is a substance that counteracts the action of another drug
• Antitoxins neutralize a toxin
• Antivenins are antitoxins that neutralize the venom of the offending snake or spider

Continuous Patient Monitoring

• ECG
• Radiology
• Electrolytes, ABGs, and labs
• Anion gap
• Osmolal gap
• Toxicology screens