CBRNE - Ricin Treatment & Management

Strictly adhere to universal precautions at all times, although secondary dermal absorption to prehospital providers is not expected. The risk of secondary aerosolization is minimal. Use protective masks, which are effective in preventing toxicity, when an overt aerosol attack is suspected.

• Management

  • ED management begins with universal precautions and the ABCs. Add a "D" for decontamination (including the removal of garments). If ingestion is possible, based on the history and presenting findings, consider gut decontamination as well.
  • Management also involves the ability to recognize, diagnose, and treat a possible biological event.
• Decontamination

  • Decontamination begins by removing garments and cleaning with soap and water.
  • If available, use a 0.5% sodium hypochlorite solution with a contact time of 15 minutes. Do not instill this solution into open abdominal, brain, or spinal cord injuries or into the eyes. It can be instilled into noncavity wounds and then removed via suction into disposable containers. This discarded solution is neutralized and nonhazardous in 5 minutes. To make a 0.5% sodium hypochlorite solution, mix 1 part bleach and 9 parts water. Make it fresh daily with a pH in the alkaline range. In the absence of this solution, copious amounts of soap and water may be used.
• Diagnosis

  • Diagnosis of an aerosolized attack or food and water contaminant with ricin is similar to that of any of the biological or chemical agents that serve as WMDs. It primarily depends on the clinical and epidemiologic setting. In cases of isolated injection, the diagnosis is extremely difficult.
  • The clinical presentation of acute lung injury in a large number of patients in a particular area should suggest a pulmonary irritant. The clinical presentation of severe gastroenteritis or hemorrhagic gastroenteritis in a large number of patients in a particular area should suggest a food and water contaminant.
  • Include ricin and other agents (eg, staphylococcal enterotoxin B, Q fever, tularemia, pneumonic plague, inhalational anthrax, chemical agents such as phosgene) in the differential diagnosis.
  • Ricin is expected to progress despite antibiotic therapy. Chest radiograph exhibits no evidence of mediastinitis, as would be expected with pulmonary anthrax.
  • Staphylococcal enterotoxin B does not progress to a life-threatening syndrome, and phosgene produces ARDS, which is mediated by exertion. Phosgene also has the characteristic odor of newly mown hay or grass and is quite irritating to mucous membranes in lethal amounts.
• Diagnostic testing: Diagnostic testing is of limited value (see Workup).
• Treatment

  • Treatment and toxicity depend on the route of exposure. Treatment is supportive, and no antidote is available for ricin.
  • Emergency department employees should obey strict universal precautions at all times.
  • For dermal exposure, a weak sodium hypochlorite solution (0.1%) and/or soap and water suffice to decontaminate the skin.
  • For GI exposure, include gastric decontamination with superactivated charcoal, volume replacement, and H2 blockers in treatment. Include chemistry panels, complete blood count, liver function panel, BUN and creatinine, urinalysis, and type and screen in the laboratory evaluation.
  • For percutaneous exposure, base treatment on excision of the injection site, if possible, within the shortest amount of time. Obtain baseline laboratory information, including arterial blood gas and fibrinogen. Although antibiotics serve no role in the treatment of ricin, withholding such therapy in an acutely septic-appearing patient would be difficult. Antibiotics may serve to prevent infection resulting from the percutaneous mechanism. Update tetanus immunization status if unknown.
  • For aerosol or pulmonary exposure, provide standard critical care treatment directed toward acute lung injury and pulmonary edema. Maintain a low threshold to secure the patient's airway and ensure adequate oxygenation and ventilation. Obtain a chest radiograph, which may show infiltrates. The clinical course progresses despite antibiotic therapy.
  • The only effective treatment for ricin toxicity is prevention. Current investigations are underway with candidate vaccines and ricin inhibitors as antidotes or to facilitate immunotoxin treatment. Pteroic acid, neopterin, pterin tautomer, and guanine tautomer are particularly useful. To date, small human trials have been conducted and are promising; however, vaccine trials still require additional testing for safety and efficacy.
• Disposition: Admit and monitor any symptomatic patient and perform aggressive volume resuscitation.

Surgical consultation for local excision and removal is warranted for parenteral exposures when a retained foreign body is located.