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خرید پکیج
تعداد آیتم قابل مشاهده باقیمانده : -12 مورد

Recognition and initial treatment of chemical weapons exposure

Recognition and initial treatment of chemical weapons exposure
Chemical Mechanism of action Clinical findings Decontamination* Management
Nerve agents:
  • Tabun (GA)
  • Sarin (GB)
  • Soman (GD)
  • Cyclosarin (GF)
  • VX (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate)
 Anticholinesterase:
  • Muscarinic, nicotinic, and CNS effects
 Cholinergic crisisΔ with either:
  1. Sudden collapse, coma, apnea, and convulsions or
  2. Progression from local effects (refer below) to generalized systemic effects (fasciculations, coma, seizures, paralysis):
    • Local effects from vapor inhalation: Miosis, rhinorrhea, salivation, difficulty breathing
    • Local effects from liquid on skin: Local sweating, twitching, and fasciculations
  • Vapor:
    • Move to fresh air
    • Remove clothes
    • Wash hair
  • Liquid:
    • Remove clothes
    • Use Reactive Skin Decontamination Liquid for spot decontamination
    • Irrigate skin with water or soapy water
    • Irrigate eyes and wounds with sterile saline or water
 Do not delay antidotal therapy if nerve agent exposure is suspected◊:
  • Atropine§¥, pralidoxime, and a benzodiazepine (eg, diazepam or midazolam) depending on severity

For specific dosing and indications, refer to UpToDate topics on chemical terrorism.
Cyanide (AC) Cytochrome oxidase inhibition:
  • Cellular anoxia, lactic acidosis
  • Tachypnea
  • Coma
  • Seizures
  • Apnea
  • Fresh air
  • Skin:
    • Soap and water¥
 Do not delay antidotal therapy if cyanide poisoning is suspected◊:
  • Hydroxocobalamin (Cyanokit) or
  • Cyanide antidote kit: Amyl nitrite perles for inhalation and intravenous preparations of sodium nitrite and sodium thiosulfate

For specific dosing and indications, refer to UpToDate topics on cyanide poisoning and chemical terrorism.
Pulmonary, type I (central, eg, hydrogen chloride, hydrogen fluoride) or combination agents (eg, chlorine) Type I:
  • Various mechanisms causing irritation (including irritative laryngospasm) and partial to total airway obstruction

Combination:

  • In addition to type I, various reactions causing fluid leakage and pulmonary edema
 Type I:
  • Airway noise (coughing, sneezing, hoarseness, inspiratory stridor, wheezing)
  • Irritation of eyes, nose, and throat
  • Irritative laryngospasm

Combination:

  • Type I findings
  • Delayed onset chest tightness or shortness of breath
  • Fresh air
  • Skin:
    • Irrigate with water
  • Provide humidified oxygen
  • Inhaled racemic epinephrine for stridor or upper airway obstruction
  • Pulmonary toilet
  • Bronchoscopy for severe upper airway obstruction
  • Give antibiotics only after identification and testing of causative organism
  • For combination agents, as above, and:
    • Strict bed rest
    • Positive pressure ventilation, as needed to support breathing
    • Admit to a pulmonary ICU
Type II pulmonary agents (eg, phosgene [GG]) or combination agents (eg, chlorine) Type II:
  • Various reactions causing fluid leakage and pulmonary edema

Combination:

  • In addition to type II effects, various mechanisms causing irritation (including irritative laryngospasm) and partial to total airway obstruction

Delayed onset chest tightness and shortness of breath

Combination, rapid onset of:

  • Airway noise (coughing, sneezing, hoarseness, inspiratory stridor, wheezing)
  • Irritation of eyes, nose, and throat
  • Irritative laryngospasm
  • Fresh air
  • Skin:
    • Irrigate with water
  • Strict bed rest
  • High flow nasal cannula‡, nasal CPAP‡, or positive pressure ventilation, as needed to support breathing
  • Admit to a pulmonary ICU
  • For upper airway symptoms:
    • Provide humidified oxygen
    • Pulmonary toilet
    • Inhaled racemic epinephrine for stridor upper airway obstruction
    • Bronchoscopy for severe upper airway obstruction
    • Give antibiotics only after identification and testing of causative organism
Crowd-control agents:
  • CS (o-chlorobenzylidene malononitrile)
  • CN (mace)
  • OC (oleoresin capsicum, pepper spray)

Alkylation

Release of substance P (OC)
  • Eye:
    • Tearing, pain, blepharospasm
  • Nose and throat irritation
  • Type I pulmonary effects if very concentrated exposure
  • Bronchospasm
  • Fresh air
  • Skin:
    • Flush with water or soapy water
  • Eye:
    • Water or normal saline irrigation
  • Avoid bleach
  • If no sign of an open globe, apply topical ophthalmic anesthetic drops (eg, proparacaine 0.5% 1 drop to each eye) and evaluate for corneal abrasions and other ocular injuries
  • Symptomatic support of bronchospasm (eg, oxygen, inhaled short-acting beta-2 agonists [eg, albuterol], and corticosteroids)
  • If severe exposure with signs of upper airway compromise, as above for type I pulmonary agents
Mustard compounds (eg, sulfur mustard [H]) Alkylation
  • Skin:
    • Erythema, vesicles
  • Eye:
    • Inflammation
  • Respiratory tract:
    • Inflammation
  • Skin:
    • Soap and water
  • Eyes:
    • Water (only effective if done within minutes of exposure)
 Symptomatic and supportive care for partial thickness burns, corneal toxicity, and bone marrow suppression
Lewisite (L)  
  • Skin:
    • Erythema, vesicles
  • Eye:
    • Inflammation
  • Respiratory tract:
    • Inflammation
  • Skin:
    • Soap and water
  • Eyes:
    • Water (only effective if done within minutes of exposure)
  • Symptomatic and supportive care as for partial thickness burns
  • Dimercaprol [BAL] 3 to 4 mg/kg IM every 4 to 6 hours for systemic effects in severe cases
BZ (3-quinuclidinyl benzilate) Competitive antagonism of acetylcholine at muscarinic receptors Anticholinergic effects:
  • Peripheral:
    • Dilated pupils
    • Dry mouth
    • Flushed skin
    • Tachycardia
    • Hypertension
    • Absent bowel sounds
    • Urinary retention
  • Central:
    • Delirium
    • Seizures
 Irrigate skin with water or soapy water
  • Benzodiazepines as needed for agitation
  • Physostigmine for patients with peripheral and moderate to severe central effects (eg, delirium with danger to self or others or seizures) by providers familiar with its use

For specific indications and dosing, refer to UpToDate topics on chemical terrorism and anticholinergic poisoning.

CNS: central nervous system; CPAP: continuous positive airway pressure; ICU: intensive care unit.

* Decontamination, especially for patients with significant nerve agent or vesicant exposure, should be performed by health care providers wearing adequate personal protective equipment. For first receiving facilities (eg, hospital emergency departments), this consists of nonencapsulated, chemically-resistant body suit, boots, and gloves with a full-face air purifier mask/hood. Refer to UpToDate topics on chemical weapons for more information regarding the proper performance of decontamination of chemically exposed patients.

¶ Emergent supportive of chemical exposures should always include the ABCDDs: Airway, Breathing, Circulation, immediate Decontamination (meaning immediate local, or spot decontamination of any suspicious liquid on the skin or in wounds), and Drugs (including specific antidotes).

Δ Signs of cholinergic crisis include miosis, bronchorrhea with wheezing, copious salivation, lacrimation, diaphoresis, vomiting, and diarrhea.

◊ Intraosseous route is likely equivalent to intravenous for administration of antidotes. Refer to UpToDate topics on intraosseous infusion.

§ Inhaled ipratropium bromide (500 mcg inhaled, may repeat once) may complement parenteral atropine administration for the treatment of bronchospasm.

¥ Administration of scopolamine may help preserve atropine in the setting of large numbers of patients with severe nerve gas exposure. For scopolamine dosing refer to UpToDate topics on chemical terrorism.

‡ High flow nasal cannula and noninvasive positive pressure ventilation should be avoided in patients with upper airway obstruction after combination agent (eg, chlorine) exposure.

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