Read Rosen & Barkin's 5-Minute Emergency Medicine Consult Online

Authors: Jeffrey J. Schaider,Adam Z. Barkin,Roger M. Barkin,Philip Shayne,Richard E. Wolfe,Stephen R. Hayden,Peter Rosen

Tags: #Medical, #Emergency Medicine

Rosen & Barkin's 5-Minute Emergency Medicine Consult (403 page)

BOOK: Rosen & Barkin's 5-Minute Emergency Medicine Consult
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CODES
ICD9
  • 780.91 Fussy infant (baby)
  • 780.92 Excessive crying of infant (baby)
  • 789.7 Colic
ICD10
  • R10.83 Colic
  • R68.11 Excessive crying of infant (baby)
  • R68.12 Fussy infant (baby)
IRRITANT GAS EXPOSURE
Patrick M. Whiteley

Sean M. Bryant
BASICS
DESCRIPTION
  • An irritant is any noncorrosive substance that on immediate, prolonged, or repeated contact with respiratory mucosa will induce a local inflammatory reaction.
  • Respiratory irritants are inhaled as gases, fumes, particles, or liquid aerosols.
  • Inhaled irritants:
    • Pulmonary toxicity is determined primarily by their water solubility.
  • Inhalation accidents frequently involve a mixture of irritant gases as well as chemical asphyxiants:
    • Carbon monoxide
    • Hydrogen cyanide
    • Hydrogen sulfide
    • Oxides of nitrogen
  • Risk factors include exposure to potential irritants:
    • Occupational
    • Leisure
    • Intentional
    • Accidental
  • Pathophysiology:
    • Cellular injury through interaction with respiratory mucosal water with subsequent formation of acids, alkalis, and free radicals
ETIOLOGY
  • Settings:
    • Industrial: Chemical manufacturing, mining, plastics, and petroleum industries
    • Home: Improper use or storage of cleaning chemicals
    • Fires: Combustion yields toxic gases.
    • Civil Disturbance: Riot control agents.
  • Immediate onset
    of upper airway inflammation with highly water-soluble irritant gases or with aerodynamic diameter >5 mm:
    • Ammonia (fertilizers, refrigerants, dyes, plastics, synthetic fibers, cleaning agents):
      • Immediate symptoms range from mild edema and erythema to full-thickness burns and airway obstruction.
    • Sulfur dioxide (fumigants used on produce, bleaching, tanning, brewing, wine making, combustion of coal, and smelting of sulfide-containing ores):
      • Combines with water, forming sulfuric acid.
    • Hydrogen chloride (formed during combustion of chlorinated hydrocarbons such as polyvinyl chloride):
      • Combines with water, forming hydrochloric acid.
    • Chloramine (generated when ammonia and bleach are mixed):
      • When exposed to moist surfaces, releases hypochlorous acid.
    • Acrolein (production of plastics, pharmaceuticals, synthetic fibers; formed during combustion of petroleum products, cellulose, wood, paper):
      • May cause protein damage via free radical production and sulfhydryl binding.
    • Formaldehyde (production of plywood, particle board, insulation; combustion product of gas stoves and heaters):
      • Combines with water to form sulfuric acid and formic acid.
    • Hydrogen fluoride (combustion of fluorinated hydrocarbons):
      • Depletes calcium stores, resulting in cell death.
    • Riot control agents (Capsaicin [OC], Chlorobenzylidenemalononitrile [CS], and Chloroacetophenone [CN]):
      • Lacrimation agents which cause temporary ocular discomfort.
  • Latent period
    of minutes to hours before onset of symptoms with irritant gases of intermediate water solubility or aerodynamic diameter of 1–5 mm:
    • Chlorine (product of chlorinated chemicals; bleaching agent):
      • Upper and lower airway damage after reacting with water to form hydrochloric and hypochlorous acids
  • Delayed onset
    of symptoms up to 24 hr after inhalation with irritant gases of poor water solubility or aerodynamic diameter <1 mm (with little or no warning of exposure):
    • Oxides of nitrogen produced:
      • In manufacture of dyes and fertilizers
      • By electric arc welding and gas blowing
      • By fermentation of nitrogen-rich silage (silo-filler’s disease)
      • In combustion of nitrocellulose and polyamides
    • Phosgene/carbonyl chloride (arc welding and pesticide production: Combustion of chlorinated hydrocarbons and solvents)
    • Ozone (produced during arc welding)
    • Cadmium oxide (oxyacetylene welding and electroplating)
DIAGNOSIS
SIGNS AND SYMPTOMS
  • Dependent on water solubility
  • Highly water-soluble gases:
    • Eye, nose, throat burning
    • Shortness of breath
    • Wheezing
    • Cough
    • Hoarseness
    • Stridor
    • Obstruction
  • Intermediate water solubility:
    • Upper and lower tract involvement
    • Mucosal irritation
    • Bronchospasm
    • Dyspnea
    • Wheezing
    • Cough
    • Rales
    • Possible delayed pulmonary edema
  • Other:
    • Dermal irritation
    • Headache
    • Nausea
    • Vomiting
    • Confusion
    • Seizures
    • Syncope
History
  • Known exposures
  • Type of chemical/industry
  • Rapidity of symptom
  • Material safety data sheet from exposure site
  • Water solubility of agent
Physical-Exam
  • HEENT:
    • Conjunctival injection
    • Lacrimation
    • Chemosis
  • Respiratory
  • Stridor
    • Voice changes
    • Dyspnea
    • Wheezing
    • Cough
  • GI:
    • Vomiting
  • Dermatologic:
    • Skin erythema/irritation
    • Erythematous rash
  • Neurologic:
    • Confusion
    • Seizure activity
ESSENTIAL WORKUP

History of exposure to irritant gases in addition to noted symptoms confirm diagnosis.

DIAGNOSIS TESTS & NTERPRETATION

ECG in the following patients:

  • Elderly
  • Cardiac history
  • Evidence of significant pulmonary symptoms
Lab
  • Arterial blood gas to assess:
    • Oxygenation
    • Ventilation status
    • pH
    • Pulse oximetry is unreliable.
  • Carbon monoxide level:
    • If smoke inhalation with concomitant irritant gas inhalation (see “Carbon Monoxide Poisoning”)
  • Methemoglobin level:
    • If oxides of nitrogen are suspected
  • Serum calcium level:
    • If hydrogen fluoride is suspected
  • Lactate:
    • Elevation may indicate cellular poisoning from carbon monoxide or cyanide.
  • Pregnancy test in all females of childbearing age
  • Rapid dextrose
  • Cardiac enzyme levels if acute coronary syndrome suspected
Imaging

CXR:

  • Frequently normal on initial presentation
  • May take up to 24 hr to reveal pulmonary edema or evidence of diffuse injury.
Diagnostic Procedures/Surgery
  • Spirometry:
    • Assess evidence suggesting airway narrowing and bronchoconstriction.
  • Direct laryngoscopy:
    • Assess evidence of upper airway edema.
  • Corneal fluorescein:
    • Assess evidence of corneal burns/injury.
DIFFERENTIAL DIAGNOSIS
  • Asthma exacerbation
  • Allergic stimuli (pollen)
  • Physical stimuli (cold air)
  • Bronchitis
  • Pneumonia
  • Occupational asthma
  • Hypersensitivity pneumonitis
  • Congestive heart failure
TREATMENT
PRE HOSPITAL

Rescuer’s goal is to prevent self-contamination with use of protective clothing or equipment (self-contained breathing apparatus).

INITIAL STABILIZATION/THERAPY
  • ABCs:
    • 100% oxygen through a tight-fitting, nonrebreathing face mask
    • Early intubation may be necessary to protect airway from edema.
    • Mechanical ventilation
    • Continuous positive airway pressure or positive end-expiratory pressure may enhance oxygenation.
  • Decontaminate by removing clothes and irrigating skin and ocular tissues.
ED TREATMENT/PROCEDURES
BOOK: Rosen & Barkin's 5-Minute Emergency Medicine Consult
12.93Mb size Format: txt, pdf, ePub
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