Hydrocarbon poisoning is a common toxicological emergency, especially in children. Hydrocarbons include petroleum products such as kerosene, gasoline, diesel, turpentine, and lighter fluids, as well as polyethylene glycol (PEG) used in pharmaceuticals and industrial formulations. Toxicity results from aspiration, inhalation, or ingestion, with petroleum products posing a high risk of aspiration pneumonitis. Understanding their toxic mechanisms and clinical management is essential for effective treatment.
Classification of Hydrocarbons
- Aliphatic hydrocarbons: kerosene, gasoline, diesel
- Aromatic hydrocarbons: benzene, toluene, xylene
- Halogenated hydrocarbons: carbon tetrachloride, chloroform
- Polyethylene glycol (PEG): used in medicines, cosmetics, and industrial products
Properties Influencing Toxicity
- Low viscosity: increases risk of aspiration
- High volatility: enhances inhalational toxicity
- High lipid solubility: facilitates CNS penetration
Petroleum products have low viscosity and high volatility, making them dangerous even in small amounts.
Mechanism of Toxicity
Petroleum Products
- Aspiration leads to direct damage to pulmonary tissues
- Hydrocarbons disrupt surfactant → alveolar collapse
- Inflammatory response causing chemical pneumonitis
- CNS depression in high-dose exposures
PEG (Polyethylene Glycol)
- Generally low systemic toxicity
- Large exposures may cause diarrhea and dehydration
- High molecular weight PEG is poorly absorbed
Clinical Features
1. Petroleum Products
Respiratory Symptoms
- Coughing and choking
- Dyspnea and tachypnea
- Wheezing or crepitations
- Cyanosis in severe cases
- Signs of aspiration pneumonitis
Central Nervous System
- Dizziness
- Headache
- Drowsiness
- Ataxia
Gastrointestinal Symptoms
- Nausea and vomiting
- Abdominal pain
Cardiac Effects
- Arrhythmias (more common with halogenated hydrocarbons)
2. PEG Exposure
- Nausea and vomiting
- Diarrhea
- Dehydration and electrolyte imbalance
Severe systemic toxicity is rare with PEG unless exposure is massive.
Complications
- Aspiration pneumonitis: primary life-threatening complication
- ARDS (Acute Respiratory Distress Syndrome)
- Hypoxia
- Secondary bacterial pneumonia
- Ventricular arrhythmias (especially with aromatic hydrocarbons)
Investigations
- Chest X-ray (signs of aspiration may appear after 4–6 hours)
- Pulse oximetry and arterial blood gases
- Electrolytes and renal function
- ECG in suspected cardiac involvement
Hydrocarbon levels in blood are not clinically useful.
Management
1. Initial Stabilization
- Ensure airway patency
- Administer oxygen
- Support ventilation if required
2. Decontamination
Gastric lavage is contraindicated due to high aspiration risk.
- Do NOT induce vomiting
- Activated charcoal is generally ineffective and avoided
3. Respiratory Support
- Humidified oxygen
- Nebulized bronchodilators for wheezing
- Mechanical ventilation in severe pneumonitis
4. Treatment of Complications
- IV fluids for dehydration
- Antibiotics only if bacterial infection is suspected
- Steroids are not routinely recommended
- Monitor for ARDS
5. PEG Management
- Supportive care with hydration
- Correct electrolyte imbalance
- Monitor renal function in large exposures
When to Admit
- Symptomatic patients
- Children with suspected aspiration
- Respiratory distress or hypoxia
- Abnormal chest X-ray
Prevention
- Store hydrocarbons out of reach of children
- Do not keep petroleum products in drink containers
- Ensure proper ventilation when using volatile solvents
Detailed Notes:
For PDF style full-color notes, open the complete study material below:
PATH: PHARMD/ PHARMD NOTES/ PHARMD FOURTH YEAR NOTES/ CLINICAL TOXICOLOGY/ HYDROCARBONS: PETROLEUM PRODUCTS AND PEG.