Smoke Inhalation & Thermal Injuries

MODULE G3

Chapter 43: pp. 520-531

Smoke Inhalation & Thermal Injury

• Fire related deaths are the third most common cause of accidental death in the US.

• Prognosis• Extent and duration of smoke exposure.• Chemical composition of the smoke.• Size and depth of body surface burns.• Temperature of gases inhaled.• Age.• Pre-existing health problems.

Anatomic Alterations

• Inhalation• Thermal Injury.• Steam Inhalation - rare• Chemical Injury from toxic gas.

• Body surface burns.

Thermal Injury

• Inhalation of hot gases:• Confined to the upper airway.• Airways distal to the larynx are usually spared

serious injury.• Upper airways ability to cool hot gases.• Reflex laryngospasm.• Glottic closure.

Thermal Injury

• Acute upper airway obstruction.• Occurs in 20-30% of cases.• Supraglottic region.• May rapidly develop after rapid IV fluid

administration.

Chemical Injury

• Smoke Inhalation• Damages the airway down to the alveoli.• Substances in smoke are extremely caustic

and poisonous to the body.• COHB%• Cyanide poisoning• Formaldehyde• Ammonia• Sulfur dioxide

Medical Challenge

• Injury from burns can affect every organ system

• Multiple organ failure

Stages of Smoke Inhalation and Burns

• Early or Resuscitation Phase • First 24 hours

• Intermediate Phase• 2-5 days

• Late Phase• After 5 days

Stage I

• CO Poisoning • Affinity for the Hb is 200 – 250 times greater

than oxygen.• Left shift in the oxygen dissociation curve.• Levels greater than 40% is severe exposure.

• PaO2 may be normal or high.

• SaO2 will be low – measure with co-oximeter.

• DO NOT USE A PULSE OXIMETER

Stage I

• Cyanide Poisoning• Burning of polyurethane materials• A cyanide blood level in excess of 1 mg/L is

usually fatal• Cyanide interferes with oxygen utilization in

the mitochondria • Anaerobic metabolism & lactic acidosis

• PaO2 & SaO2 can be normal

Stage I

• Tissue Hypoxia • COHb poisoning (Anemic Hypoxia)• Cyanide poisoning (Histotoxic Hypoxia)

• Metabolic acidosis

Stage I

• Thermal Injury• Laryngospasm and glottic closure• Airway obstruction• Establish an airway

• Chemical Injury• Inflammatory Response

Stage I

• Hypovolemic Shock• Blood vessels become “Leaky”• Massive fluid shift from the blood vessels into

the tissues (third spacing)• Generalized body edema

• Decreased Chest Wall Compliance• Skin loses its elasticity• Difficult to inflate the lungs

Stage I

• Hypermetabolic State• Massive release of catecholamines from stress• Nutrition is very important

• Patients need lots of calories

• VO2 & VCO2 increases

• Acute Lung Injury (ALI)• Decreased PaO2/FIO2 ratio

. .

Stage II

• Pulmonary Edema• Decreased COP from loss of protein.• Rapid infusion of fluids.

• ARDS

• Mechanical ventilation

• Stress induced hyperglycemia develops.

• Immune system becomes depressed.• Infection sets in

Stage III

• Infections• Pneumonia

• Sepsis and multi-organ failure

• DIC (Disseminated Intravascular Coagulation)

• Pulmonary embolism

• Long term effects• Restrictive and Obstructive disorders• Bronchiolitis Obliterans

Assessment

• Level of Consciousness

• Burns to face or upper airway

• Hoarseness• Altered voice• Painful swallowing• Stridor

• Cherry red skin color

• Tachypneic• Sputum

• Black, sooty• White frothy • Purulent (later finding)

• Nausea/vomiting• Convulsions

Management

• Treat any unconscious or lethargic patient as a medical emergency.• Suspect hypoxia.• Intubate to protect the airway.

• 100 % oxygen &/or Hyperbaric Chamber• PaO2 in a hyperbaric may rise to 1,500 mm Hg

• Cyanide Poisoning• Amyl nitrite, Sodium nitrite, Sodium thiosulfate

Management

• Fluid Administration

• Bronchoscopy• Evaluate the extent of damage.• Remove mucous plugs.• Used for difficult intubations.

• CPAP with 100% oxygen

• Mechanical Ventilation• Acute Respiratory failure or • Acute Oxygenation failure

Management

• Analgesics for Pain

• FEED, FEED, FEED

• Steroids are controversial

• Aerosol Therapy• Bronchodilators (B2 agonists)• Mucolytics

Management

• Antibiotics

• Culture sputum, blood, wounds

• Prophylactic heparin therapy for PE

• Escharotomy • Cutting of burned skin• Help to treat the low compliance of the chest

wall

Important Points

• Level of Consciousness• Determine need for airway

• 100% Oxygen and Hyperbaric Chamber

• Never use Pulse Oximeter. • Well maybe…