1. Acute Inhalation Injury
By : ziba Loukzadeh, M.D
Occupational Medicine department
Yazd University of Medical Sciences

2. Types of inhaled substances
Aerosol
Fume
Mist
Gas
Vapor
Smoke
Dust

3. Properties of inhalants
Gas (water solubility)
High water solubility: ammonia, SO2,HCL
Immediate injury to upper airway
person quickly leave area
low water solubility: Phosgene, ozone, NOX
Injury of terminal bronchiole & alveolus
person remain in area
Intermediate water solubility: chlorine

4. Properties of inhalants
Particle (size) :
>10µm :upper airway
2.5-10µm :lower air way
<2.5µm :lung parenchyma

5. Acid (chlorine, HCL,SO2, NOX, phosgene) Alkali (ammonia)
coagulation
Alkali (ammonia)
liquefaction
Reactive o2 species(ozone, NOX, chlorine)
Lipid peroxidation

6. Pathophysiology Direct contact & tissue damage
Direct smooth muscle contraction
Stimulation of neuronal receptors
Influx of inflammatory cells & mediators
Leakage of interstitial fluid & edema
Decrease epithelium’s barrier function

7. Classification of injury
Acute (1-2 days of exposure)
Laryngeal edema
Airflow obx- asthma & bronchitis
Pneumonitis, pulmonary edema
ARDS
Persistent sequelae( weeks to months)
COPD
RADS (Reactive Airway Dysfunction Syndrome)
Bronchitis
Bronchiolitis obliterans
BOOP

8. Upper airway injury- presentation
Burn of skin, eyes, nasal & throat
Rhinitis
Conjunctivitis
lacrimation
Sputum production
Coughing & sneezing
Airway obx
tissue edema, thick secretion, sloughed cells
Laryngospasm
hoarseness ,stridor

9. Conductive airway Acute Hospitalization for observation
Tracheobronchitis & bronchorrhea
Hospitalization for observation
Asymptomatic person+ objective evidence of respiratory compromise
Airflow
O2sat
Abnormal CXR
Asymptomatic person+ history of intense exposure
With respiratory symptoms

10. Conductive airway Baseline spirometry repeat after 24-48h
Significant decrement:
FEV1≤80%
Decrease ≥ 10% from baseline

11. Conductive airway Symptomatic person without decrement in airflow
Inhaled steroid +bronchodilator
Symptomatic person with airflow obx
Short course of systemic steroids
AND

12. Conductive airway( chronic injury )
COPD (chlorine, SO2)
Intensity of exposure
Smoking
Pre-existing pulmonary dx Rx
Smoking cessation
Bronchodilator
Steroids O2

13. Conductive airway( chronic injury)
RADS (sulfuric acid, chlorine, ammonia, smoke, household cleaner)
Persistence of airway reactivity after inhalational injury
Single, acute, high intensity exposure
Previous exposure: -
Pre-existing respiratory dx: - Rx
Steroids
bronchodilators

14. Lung parenchyma (acute injury )
Exposure
Low water soluble
Massive high/intermediate water soluble
Pneumonitis
dyspnea, cough
Hypoxemia
Mild restriction
Diffuse bilateral infiltration
Rx:o2 +/- mechanical ventilation
Pulmonary edema , ARDS

15. Lung parenchyma (chronic injury)
Bronchiolitis obliterans (ammonia, mercury, NOx, SO2)
Survivors of acute lung injury asymptomatic period irreversible obx (after 1-3 wks)
PH/EX: early inspiratory crackles
CXR: NL or hyperinflation
Infiltration: generally –
PFT: Obx +/- restriction
Rx: 6-month trial of steroids

16. --Constrictive bronchiolitis pattern in 41-year-old male double lung transplant recipient with bronchiolitis obliterans syndrome
Pipavath, S. J. et al. Am. J. Roentgenol. 2005;185:
Copyright © 2007 by the American Roentgen Ray Society

17. Lung parenchyma (chronic injury)
BOOP (ammonia, mercury, SO2)
Proliferative bronchiolitis
Like Community acquired pneumonia:
Non-productive cough, DOE, Malaise, fever, weigh loss, ….
PH/EX: NL or late respiratory crackle
CXR: Bilateral, most peripheral patchy opacity start as focal lesions, wax & wane
PFT: NL or restrictive
Rx: at least 6-month steroid
Dramatically response

18. Evaluation ABG CXR PFT (spirometry, peak flowmetry)
Methacholine challenge
Lung Bx
24h observation for low water soluble inhalants

19. Management Removal from exposure Irrigation with large amount of water
Suction of secretion
Airway obx
Inhaled epinephrine
Endotracheal intubation
Tracheotomy
O2 if hypoxemia
Bronchodilator
Corticosteroids
No influence
Extensive edema: suggested
Prophylactic Antibiotic: NO
Management of Skin & mucosal surface burns
Ophthalmologic consultation

20. Prevention Engineering controls Regular maintenance Worker training
Plan to handle accident
Evacuation plan
Availability of emergency provision (o2, shower, respirator)

21. Ammonia Manufacturing industry Chemical industry Agricultural industry
Manufacture of explosives, cyanide, synthetic fiber, plastic
Chemical industry
Petroleum refining
Agricultural industry
Soil fertilizer

22. Ammonia Highly water soluble Injury:
Thermal burn
Alkali burn
Irritation of eye, skin & upper & conductive airway
Parenchymal injury in high exposure
Biphasic pattern

23. Chlorine (CL2) Use: Intermediate water solubility
Bleaching agent (textile & paper industry)
Water purification (swimming pool & sewage treatment)
Intermediate water solubility
Mixing of chlorine compound & other substance:
Chlorine + ammonia: chloramine gas
Household bleach+ phosphoric acid : CL2 gas

24. NOx Exposure Low water soluble Mining Acetylene welding
explosive manufacturing
In closed area with engines
Agricultural worker ( silo fillers dx)
Low water soluble

25. Phosgene (low water soluble)
Used to catalysis reactions
Polyurethane resin
TDI
Pesticide
Dye
Produced via heat decomposition of
Solvents
Paint remover
Dry cleaning fluid
Methylene chloride

26. Systemic illness from inhaled toxins
(inhalation fever)

27. Background Various causes Similar features Flu-like symptoms
Self-limited
Important differential diagnosis
- Inhalational lung injury
- HP
- Infections

28. Characteristics
Symptoms: fever, chills, headache, cough, chest tightness, minimal dyspnea, malaise, myalgia
Signs: fever, tachycardia, tachypnea, occasionally crackles
Develop 4-8 h after exposure
Lab data: leukocytosis
CXR : NL
PFT : NL
Self-limiting: 24-48h

29. Metal fume fever Causes: - Zinc oxide
- Other metals: Mg, Cu, Cr, Ir, Ni, Ag, Al, Hg
- Cd: acute lung injury
- ZnCl2: acute lung injury
Jobs: Brass foundry, Welding or Flame-cutting of galvanized metal
Constitutional symptoms + metallic taste

30. Organic Dust Toxic Syndrome (ODTS)
Causes: moldy or damp silage, hay, moldy wood chips
Silo unloader’s syndrome (Vs. silo filler’s disease) /atypical farmer’s lung
Summer and fall
Atopy a risk factor
DD: farmer’s lung (HP)

31. Polymer Fume Fever
Causes: pyrolysis (300 –750ºC) products of polytetrafluoroethylene resins (Teflon)
Jobs: welding or flame-cutting of metals coated with PTFE, molding or extruding machines, cigarette smoking
No tolearnace
DD: acute lung injury

32. Smoke inhalation In fire exposed person Smoke
Thermal content: supraglotic region
Chemical content: vary from fire to fire
Irritants
Acrolein
Ammonia
Chloride
HCL
SO2
phosgene
Chemical asphyxiants
CO (incomplete combustion)
Cyanide (combustion of acrylic, nylon, polyurethane)

33. Significant smoke inhalation
Steam exposure
Closed space
Exposure to plastic fumes
Burn of facial hair
Altered consciousness
Respiratory symptoms
Lactic acidosis
COHg>20%

34. Smoke inhalation (management)
Evaluation of COHg & serum PH
Upper airway burn: endotracheal intubation
Significant smoke inhalation: 24h obseve

35. Thank you!
Any Question?