Pulmonary Intoxicant

Aka: Pulmonary Intoxicant, Green Cross Agent, Phosgene, Chlorine

1. History
   1. Phosgene synthesized in 1812 by John Davy
   2. First used as Chemical Weapon 1917 by Germany
   3. Transported as liquid on rail lines
   4. Used as precursor for chemical manufacture
2. Toxicity
   1. Chlorine LCt50: 6000 mg-min/m3
   2. Phosgene LCT50: 3200 mg-min/m3
3. Agents
   1. Phosgene (CG)
      1. Vesicant (Blister Agent) when in liquid form
   2. Diphosgene (DP)
   3. Chloropicrin (PS)
   4. Chlorine (CL)
   5. Perfluoroisobutylene (PFIB)
      1. Teflon combustion (e.g. aircraft insulated wiring)
   6. HC smoke (smoke containing zinc)
      1. Smoke grenades: white obscurant smoke
   7. Oxides of nitrogen (burning munitions)
4. Detection
   1. Observation
      1. Forms white cloud on explosion or dispersion
      2. Settles into colorless low lying gas
   2. Odor: Phosgene
      1. Sweet, newly mown hay
      2. Freshly cut grass
      3. Corn
   3. Detector kits sensitivity for Phosgene
      1. MINICAMS (50 ppbv)
      2. Monitox Plus (0.25 TWA)
      3. Draeger tubes (0.02-0.6 ppm)
      4. ICAD (25 mg/m3)
      5. M18A2 (12.0 mg/m3)
      6. M90 (>50 ppm)
      7. M93A1 Fox (115 mg/m3)
5. History of comorbid conditions
   1. Asthma or reactive airway disease
   2. Tobacco smoking
6. Symptoms and Signs
   1. Eye irritation
   2. Airway irritation
      1. Cough
      2. Sneezing
      3. Hoarseness
      4. Copious watery airway secretions
   3. Dyspnea
   4. Chest tightness
   5. Delayed pulmonary edema
7. Differential Diagnosis
   1. Riot control agents
   2. Nerve agents
   3. Vesicant Agents
8. Labs
   1. No specific Lab testing
   2. Hematocrit increased
   3. Arterial Blood Gas (ABG)
      1. Low PaO2
      2. Low PaCO2
   4. Peak expiratory flow decreased
9. Prognosis: Indicators of severe exposure
   1. Signs or symptom onset in first 4 hours after exposure
10. Radiology
    1. Chest XRay
       1. Hyperinflation
       2. Delayed pulmonary edema
       3. No cardiomegaly
    2. Ventilation Perfusion Scan (V/Q Scan)
       1. Sensitive but not specific
11. Management
    1. Terminate exposure
    2. Decontamination
       1. Vapor exposure
          1. Fresh air
       2. Liquid exposure
          1. Copious water irrigation
          2. Hypochlorite 0.5%
          3. M291
    3. ABC Management
    4. Pulmonary Management
       1. Oxygen with positive pressure
       2. Treat Bronchospasm
          1. Beta-adrenergic Bronchodilators or Theophylline
          2. Solu-Medrol 125 mg q6h
       3. Observe for signs respiratory distress
    5. Intravenous fluid hydration with crystalloid
    6. Rest and Observation
12. Triage: Patients presenting within 12 hours
    1. Immediate
       1. Pulmonary edema with ICU available
    2. Delayed
       1. Dyspnea without other signs
       2. Re-triage hourly
    3. Minimal
       1. Asymptomatic with exposure
       2. Re-triage every 2 hours
    4. Expectant
       1. Pulmonary edema, cyanosis, or Hypotension
       2. Ominous if onset within 6 hours of exposure
13. Triage: Patients presenting over 12 hours
    1. Immediate
       1. Pulmonary edema if ICU within hours
    2. Delayed
       1. Re-triage every 2 hours
       2. Discharge if recovering and 24 hours observation
    3. Minimal
       1. Asymptomatic
    4. Expectant
       1. Persistent Hypotension despite ICU
14. Prevention
    1. Activated Charcoal in chemical protective mask
       1. Absorbs Phosgene and offers complete protection
15. Complications
    1. Pulmonary fibrosis
16. References
    1. Medical Response to Chemical Warfare and Terrorism
       1. US Army Medical Research Institute Chemical Defense
       2. Video-Teleconference: 4/20/00 to 4/22/99
       3. Video-Teleconference: 12/5/00 to 12/7/00
       4. Text: 3rd Edition, December 1998