Lewisite (L)

Diagnosis

1.
Skin: gray area of dead epithelium with 5 mins, erythema within 30 mins, blisters in 2-3 hrs, severe tissue necrosis

2.
Eyes: blepharospasm, conjunctival edema

3.
Airway: pseudomembrane formation, nasal irritation

4.
Intravascular fluid loss, hypovolemia, shock, organ congestion, leukocytosis, miosis, immediate pain on contact

5.
Odor: fruity or geranium

6.
Lab: blood arsenic >7 mcg/100ml is abnormal
History

1.
First synthesized by US Army captain Wilford Lee Lewis in 1918

2.
May have been used by Japan in China (1937-1944)
Pathophysiology

1.
Damages eyes, skin, and airways by direct contact

2.
Absorbed from skin, eyes, respiratory tract, ingestion, and via wounds

3.
Increases capillary permeability; produces hypovolemia, shock, organ damage

4.
Oily, colorless liquid; low water solubility; persists in ground plants for wks

5.
Trivalent arsenic compound; produces systemic toxicity e.g. hemolysis

6.
More volatile than mustard

7.
Half life: 55-75 hrs

8.
Nasal irritation at 8 mg-min/m3; odor noted at 20 mg-min/m3

9.
Dermal dose: lethal: 38 mg/kg (2 ml on skin)

10.
Dermal absorbtion: 100,000 mg/min/m3

11.
Liquid causes vesication at 14 mcg

12.
LD50 applied to skin is 2.8 grams
Decontamination

1.
M291 kit

2.
5% hypochlorite soln immediately

3.
Water in large amounts

4.
Rubber gloves/goggles

5.
Ocular: remove contact lenses, irrigate with 0.9% saline or H2O for 15 mins

6.
Topical or ocular 5% BAL ointment within 15 mins of dermal or 2 mins of ocular exposure
Treatment

1.
Antidote: British-Anti-Lewisite (BAL, dimercaprol):

3 mg/kg q4h IM for 2 d

Then q6h on 3rd day

Then q12h up to 10 d

Avoid SQ leakage

2.
Immediate decontamination

3.
Symptomatic management of lesions
Disposition

1.
Admit

2.
Notify CDC & local health dept
Military Detection/Treatment Kits
(See Chemical Agent ID/Detection)

1.
M256A1, M272, MINICAMS, the ICAD, M18A2, M21, M90, M93A1 Fox, Bubbler, CAM, and DAAMS, M8 paper, or M9 paper

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