smoke inhalation

Overview of Smoke Inhalation and Thermal Injuries

  • Fire is a significant cause of injury, death, and economic loss.

  • Residential fires are the most common cause of burn-related injuries.

  • Smoke inhalation contributes to 50-90% of deaths in burn victims.

  • Smoke inhalation injuries occur in 10-35% of patients in burn centers.

Thermal Injury

  • Caused by inhalation of hot gases affecting primarily the upper airway: nasal cavity, oral cavity, and pharynx.

  • Major injuries from heat exposure generally do not occur below the larynx, except in rare cases of steam inhalation.

Anatomic Alterations

  • Thermal Injury:

    • Symptoms: blistering, mucosal edema, vascular congestion, epithelial sloughing, thick secretions, airway obstruction.

  • Smoke Inhalation Injury:

    • Pathological effects include inflammation, bronchospasm, excessive secretions, atelectasis, pulmonary edema, ARDS (Acute Respiratory Distress Syndrome).

Stages of Smoke Inhalation Injury

  • Early Stage (0-24 hours):

    • Initial inflammation leads to bronchospasm and obstructive secretions.

    • May develop ARDS and pulmonary edema.

  • Intermediate Stage (2-5 days):

    • Upper airway injuries improve, but lung damage peaks.

    • Mucous retention increases bacterial colonization, risk of bronchitis and pneumonia.

  • Late Stage (5+ days):

    • Concern for infections leading to sepsis, multiorgan failure, and pulmonary embolism.

    • Long-term risks: restrictive and obstructive lung disorders.

Severity and Depth of Burns

  • First Degree: Superficial, outer epidermis, heals in 6-10 days.

  • Second Degree: Extends to dermis, blisters present, heals in 7-21 days.

  • Third Degree: Full thickness burn, severe damage, may require grafts.

Clinical Manifestations

  • Symptoms of smoke inhalation include tachypnea, increased heart rate, and respiratory issues.

  • Physical examination reveals signs of airway obstruction, cyanosis, and abnormal breath sounds.

General Management of Smoke Inhalation and Burns

  • Initial assessment of airway, respiratory and cardiovascular status, burn percentage, and depth of burns.

  • Fluid resuscitation: 4 mL/kg/% BSA burned per 24 hours.

  • Airway management is critical; intubation may be necessary for signs of impending airway obstruction.

  • Implement protocols for respiratory care, including oxygen therapy and ventilation support as needed.

Prognostic Factors in Fire Victims

  • Prognosis is influenced by smoke exposure duration, chemical composition, extent of burns, gas temperature, age, and preexisting health conditions.

  • Mortality rate doubles with smoke inhalation and full-thickness burns.

Complications of Smoke Inhalation and Thermal Injuries - Complications from smoke inhalation can be severe and may include:

  • Acute Respiratory Distress Syndrome (ARDS): A life-threatening condition characterized by rapid onset of widespread inflammation in the lungs, leading to respiratory failure.

  • Pulmonary Edema: Accumulation of fluid in the lungs, causing breathing difficulties and decreased oxygenation.

  • Bronchitis and Pneumonia: Higher risk of infections due to mucous retention and bacterial colonization in the lungs.

  • Sepsis: A severe systemic reaction to infection, which can lead to organ failure and death.

  • Long-term Respiratory Disorders: Patients may experience restrictive or obstructive lung diseases following smoke exposure.

  • Psychological Effects: Survivors may suffer from PTSD, anxiety, and depression after experiencing traumatic burn injuries.

  • Early Stage (0-24 hours): - Initial inflammation leads to bronchospasm and obstructive secretions. - May develop ARDS and pulmonary edema.

  • Intermediate Stage (2-5 days): - Upper airway injuries improve, but lung damage peaks. - Mucous retention increases bacterial colonization, risk of bronchitis and pneumonia.

  • Late Stage (5+ days): - Concern for infections leading to sepsis, multiorgan failure, and pulmonary embolism. - Long-term risks: restrictive and obstructive lung disorders.

  • Total Body Surface Area (TBSA) Classification: - The total body surface area (TBSA) affected by burns is crucial for determining treatment and prognosis. - Lund and Browder Chart: A standardized chart used to assess TBSA by age and body part, accounting for varying proportions in children and adults. - Rule of Nines: A quick assessment method where the body is divided into sections, each representing approximately 9% (or multiples thereof) of the total body surface area: - Head and neck: 9% - Each upper limb: 9% (total of 18% for both) - Each lower limb: 18% (total of 36% for both) - Anterior trunk: 18% - Posterior trunk: 18% - Perineum: 1% - Clinical Relevance: Knowing the TBSA is critical for fluid resuscitation calculations and determining the need for specialized burn care.