Acute Inhalation Injury By ziba Loukzadeh M D
Acute Inhalation Injury By : ziba Loukzadeh, M. D Occupational Medicine department Yazd University of Medical Sciences
Types of inhaled substances Aerosol p Fume p Mist p Gas p Vapor p Smoke p Dust p
Properties of inhalants p Gas (water solubility) n High water solubility: ammonia, SO 2, HCL Immediate injury to upper airway p person quickly leave area p n low water solubility: Phosgene, ozone, NOX Injury of terminal bronchiole & alveolus p person remain in area p n Intermediate water solubility: chlorine
Properties of inhalants p Particle (size) : n n n >10µm : upper airway 2. 5 -10µm : lower air way <2. 5µm : lung parenchyma
p Acid (chlorine, HCL, SO 2, NOX, phosgene) n p Alkali (ammonia) n p coagulation liquefaction Reactive o 2 species(ozone, NOX, chlorine) n Lipid peroxidation
Pathophysiology n Direct contact & tissue damage Direct smooth muscle contraction p Stimulation of neuronal receptors p n n n Influx of inflammatory cells & mediators Leakage of interstitial fluid & edema Decrease epithelium’s barrier function
Classification of injury p Acute (1 -2 days of exposure) n n p Laryngeal edema Airflow obx- asthma & bronchitis Pneumonitis, pulmonary edema ARDS Persistent sequelae( weeks to months) n n n COPD RADS (Reactive Airway Dysfunction Syndrome) Bronchitis Bronchiolitis obliterans BOOP
Upper airway injurypresentation p p p p Burn of skin, eyes, nasal & throat Rhinitis Conjunctivitis lacrimation Sputum production Coughing & sneezing Airway obx n n p tissue edema, thick secretion, sloughed cells Laryngospasm hoarseness , stridor
Conductive airway p Acute n p Tracheobronchitis & bronchorrhea Hospitalization for observation n Asymptomatic person+ objective evidence of respiratory compromise Airflow p O 2 sat p Abnormal CXR p n n Asymptomatic person+ history of intense exposure With respiratory symptoms
Conductive airway p Baseline spirometry p Significant decrement: n n repeat after 24 -48 h FEV 1≤ 80% Decrease ≥ 10% from baseline
Conductive airway p Symptomatic person without decrement in airflow n p Inhaled steroid +bronchodilator Symptomatic person with airflow obx n n Short course of systemic steroids AND Inhaled steroid +bronchodilator
Conductive airway( chronic injury ) p COPD (chlorine, SO 2) n n Intensity of exposure Smoking Pre-existing pulmonary dx Rx Smoking cessation p Bronchodilator p Steroids p O 2 p
Conductive airway( chronic injury) p RADS (sulfuric acid, chlorine, ammonia, smoke, household cleaner) n n n Persistence of airway reactivity after inhalational injury Single, acute, high intensity exposure Previous exposure: Pre-existing respiratory dx: Rx Steroids p bronchodilators p
Lung parenchyma (acute injury ) p Exposure n n p Pneumonitis n n n p Low water soluble Massive high/intermediate water soluble dyspnea, cough Hypoxemia Mild restriction Diffuse bilateral infiltration Rx: o 2 +/- mechanical ventilation Pulmonary edema , ARDS
Lung parenchyma (chronic injury) p Bronchiolitis obliterans (ammonia, mercury, NOx, SO 2) n n n Survivors of acute lung injury asymptomatic period irreversible obx (after 1 -3 wks) PH/EX: early inspiratory crackles CXR: NL or hyperinflation p n n Infiltration: generally – PFT: Obx +/- restriction Rx: 6 -month trial of steroids
--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: 354 -363 Copyright © 2007 by the American Roentgen Ray Society
Lung parenchyma (chronic injury) p BOOP (ammonia, mercury, SO 2) n n Proliferative bronchiolitis Like Community acquired pneumonia: p n n 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 p Dramatically response
Evaluation ABG p CXR p PFT (spirometry, peak flowmetry) p Methacholine challenge p Lung Bx p 24 h observation for low water soluble inhalants p
Management p p Removal from exposure Irrigation with large amount of water Suction of secretion Airway obx n n n p p p O 2 if hypoxemia Bronchodilator Corticosteroids n n p p p Inhaled epinephrine Endotracheal intubation Tracheotomy No influence Extensive edema: suggested Prophylactic Antibiotic: NO Management of Skin & mucosal surface burns Ophthalmologic consultation
Prevention Engineering controls p Regular maintenance p Worker training p Plan to handle accident p n n Evacuation plan Availability of emergency provision (o 2, shower, respirator)
Ammonia p Manufacturing industry n p Chemical industry n p Manufacture of explosives, cyanide, synthetic fiber, plastic Petroleum refining Agricultural industry n Soil fertilizer
Ammonia Highly water soluble p Injury: p n n Thermal burn Alkali burn Irritation of eye, skin & upper & conductive airway p Parenchymal injury in high exposure p n Biphasic pattern
Chlorine (CL 2) p Use: n n Bleaching agent (textile & paper industry) Water purification (swimming pool & sewage treatment) Intermediate water solubility p Mixing of chlorine compound & other substance: p n n Chlorine + ammonia: chloramine gas Household bleach+ phosphoric acid : CL 2 gas
NOx p Exposure n n n p Mining Acetylene welding explosive manufacturing In closed area with engines Agricultural worker ( silo fillers dx) Low water soluble
Phosgene (low water soluble) p Used to catalysis reactions n n p Polyurethane resin TDI Pesticide Dye Produced via heat decomposition of n n Solvents Paint remover Dry cleaning fluid Methylene chloride
Systemic illness from inhaled toxins (inhalation fever)
Background Various causes p Similar features p Flu-like symptoms p Self-limited p Important differential diagnosis p - Inhalational lung injury - HP - Infections
Characteristics Symptoms: fever, chills, headache, cough, chest tightness, minimal dyspnea, malaise, myalgia p Signs: fever, tachycardia, tachypnea, occasionally crackles p Develop 4 -8 h after exposure p Lab data: leukocytosis p CXR : NL p PFT : NL p Self-limiting: 24 -48 h p
Metal fume fever p Causes: - Zinc oxide - Other metals: Mg, Cu, Cr, Ir, Ni, Ag, Al, Hg - Cd: acute lung injury - Zn. Cl 2: acute lung injury p Jobs: Brass foundry, Welding or Flamecutting of galvanized metal p Constitutional symptoms + metallic taste
Organic Dust Toxic Syndrome (ODTS) Causes: moldy or damp silage, hay, moldy wood chips p Silo unloader’s syndrome (Vs. silo filler’s disease) /atypical farmer’s lung p Summer and fall p Atopy a risk factor p DD: farmer’s lung (HP) p
Polymer Fume Fever Causes: pyrolysis (300 – 750ºC) products of polytetrafluoroethylene resins (Teflon) p Jobs: welding or flame-cutting of metals coated with PTFE, molding or extruding machines, cigarette smoking p No tolearnace p DD: acute lung injury p
Smoke inhalation p p In fire exposed person Smoke n n Thermal content: supraglotic region Chemical content: vary from fire to fire p Irritants § § § p Acrolein Ammonia Chloride HCL SO 2 phosgene Chemical asphyxiants § CO (incomplete combustion) § Cyanide (combustion of acrylic, nylon, polyurethane)
Significant smoke inhalation Steam exposure p Closed space p Exposure to plastic fumes p Burn of facial hair p Altered consciousness p Respiratory symptoms p Lactic acidosis p COHg>20% p
Smoke inhalation (management) O 2 p Evaluation of COHg & serum PH p Upper airway burn: endotracheal intubation p Significant smoke inhalation: 24 h obseve p
! u o y ? k n o n i t a s h e T A y n u Q
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