Inhalational poisoning occurs when toxic substances are absorbed through the respiratory tract after inhalation of gases, vapors, fumes, aerosols, or particulate matter. Because the lungs have a large surface area, thin alveolar membrane, and rich blood supply, inhaled toxins rapidly enter systemic circulation, often producing life-threatening effects within minutes.

Common environments:

• House fires

• Industrial accidents

• Agricultural exposure

• Enclosed spaces with combustion

• Poorly ventilated homes

Common inhaled toxins

2. Pathophysiology

Mechanisms of injury

1. Simple Asphyxiants

   • Displace oxygen → hypoxia

   • Example: methane

2. Chemical Asphyxiants

   • Interfere with cellular respiration

   • Example: carbon monoxide (binds hemoglobin), cyanide (blocks mitochondria)

3. Airway Irritants

   • Cause inflammation and edema

   • Bronchospasm

   • Delayed pneumonitis

   • ARDS

4. Pulmonary Toxicants

   • Alveolar damage

   • Non-cardiogenic pulmonary edema

3. Risk Factors

• Firefighters

• Industrial workers

• Miners

• Agricultural workers (fumigants)

• Household exposure in enclosed cooking/heating

• Children in poorly ventilated homes

• Intentional self-harm

• Chemical transport accidents

4. Clinical Features

Early Symptoms

• Eye irritation

• Cough

• Throat burning

• Dyspnea

• Headache

• Dizziness

Respiratory Signs

• Wheezing

• Stridor

• Tachypnea

• Cyanosis

• Hoarseness

• Pulmonary edema

Neurological

• Confusion

• Agitation

• Ataxia

• Seizures

• Coma

Systemic

• Hypotension

• Metabolic acidosis

• Cardiac arrhythmias

5. Diagnostic Criteria

Suspect inhalational poisoning if:

• Exposure in enclosed environment

• Multiple victims affected

• Soot around mouth/nose

• Sudden respiratory distress

• Altered consciousness after exposure

6. Investigations

Bedside

• Pulse oximetry (may be misleading in CO poisoning)

• Blood glucose

Laboratory

• Arterial blood gas (ABG)

• Carboxyhemoglobin or toxicology screen (if available)

• Lactate (severe hypoxia marker)

• Full blood count

• Electrolytes

Imaging

• Chest X-ray (initially normal, repeat at 24h)

• CT chest if worsening

Cardiac Monitoring

• ECG for arrhythmias

7. Management Principles

Treat first — confirm later

8. Non-Pharmacological Treatment

Immediate Actions

• Remove patient from exposure source

• Ensure rescuer safety

• Decontaminate clothing

Airway

Indications for early intubation:

• Hoarseness

• Facial burns

• Stridor

• Altered consciousness

• Progressive respiratory distress

Breathing

• High-flow 100% oxygen

• Ventilatory support if required

• Bronchodilators for bronchospasm

Circulation

• IV access

• Fluid resuscitation

• Cardiac monitoring

Pulmonary Care

• Humidified oxygen

• Chest physiotherapy

• Suction secretions

9. Pharmacological Treatment

Bronchospasm

• Nebulized salbutamol

• Ipratropium bromide

Airway Inflammation

• Corticosteroids (selected cases with airway edema)

Severe Lung Injury

• Consider antibiotics if secondary infection suspected

Specific Antidotes (When indicated)

10. Monitoring

Observe minimum 24–48 hours even if initially stable.

Watch for delayed:

• Pulmonary edema

• Chemical pneumonitis

• ARDS

11. Complications

Early

• Acute respiratory failure

• Airway obstruction

• Cardiac arrhythmias

Late

• Bronchiolitis obliterans

• Chronic lung disease

• Neurocognitive impairment

12. Prevention

Do’s

• Proper ventilation during cooking/heating

• Use protective masks in industry

• Install carbon monoxide detectors

• Follow chemical safety protocols

Don’ts

• Burn charcoal indoors

• Run generators indoors

• Mix cleaning chemicals

• Stay in smoke-filled rooms