Intoxication by Inhalation: Clinical Overview

1. Introduction

Many cases of intoxication result from inhaling fumes or vapors of toxic liquids. This route is characterized by rapid systemic absorption through the alveolar-capillary membrane, leading to a quick onset of toxicity.

2. Admission & Observation Criteria

Patients with persistent symptoms 6 hours post-exposure require admission for at least 24 hours.

Observe even if initially asymptomatic:

High-concentration exposure in enclosed spaces.
Underlying respiratory or cardiovascular disease.
Pediatric patients.

*Request pulmonary consultation for most admissions.

3. Initial Management (ABCDE)

Airway	Assess for stridor, hoarseness, or swelling. Early intubation if compromise is imminent.
Breathing	100% Oxygen via non-rebreather mask. Use nebulized bronchodilators for bronchospasm.
Circulation	IV access; fluids (caution: avoid exacerbating pulmonary edema).
Disability	GCS/Pupils. Altered mentation may suggest severe hypoxia, CO, or cyanide toxicity.
Exposure	Remove contaminated clothing. Copious irrigation for eyes/skin. Prevent hypothermia.

4. Investigations

ABG: Assess PaO2, PaCO2, and pH.

COHb: If CO poisoning is suspected.

Lactate: Marker for tissue hypoxia (Cyanide).

Chest X-ray: Monitor for ARDS/Edema.

Methemoglobin: If cyanosis is unresponsive to O2.

ECG/CBC/Renal: Monitor systemic impact.

5. Specific Gas Management

A. Carbon Monoxide (CO)

Treatment: 100% O2. Consider Hyperbaric Oxygen (HBO) if COHb >25% (>15% in pregnancy) or neuro-cardiac symptoms.

B. Cyanide

Treatment: Hydroxocobalamin (5g IV) or Sodium Thiosulfate (12.5g IV).

C. Irritant Gases (Chlorine, Ammonia)

Treatment: Humidified O2, bronchodilators. Monitor for delayed pulmonary edema (up to 24h).

D. Methemoglobin Inducers

Treatment: Methylene blue (1–2 mg/kg IV) if symptomatic or level >20%.

6. Consultations Checklist

Toxicologist Pulmonologist HBO Specialist Burn Center