HYDROCARBON POISONING in children

HYDROCARBON POISONING

Dr Usama Amjad

Sources:
Petrol,Kerosene,Lighter Fluid,Paraffin Oil,2 Stroke Fuel,Diesel Fuel,Solvents,White Spirit,Lubricating

Oil Furniture Polishes,Essential oils,Turpentine

PATHOPHYSIOLOGY

Hydrocarbons are aspirated into lungs during coughing ,gagging or vomiting after ingestion.

They damage the type 2 pneumocytes leading to deceased production of surfactant leading to pneumonitis

Some hydrocarbons have their specific toxicities as well e.g;

Carbon tetrachloride is hepatotoxic

Methylene chloride is metabolized to carbon mono oxide

Long term exposure to benzene may lead to acute myelogenous leukemia

Nitrobenzene,aniline dyes lead to methemoglobinemia

Halogenated hydrocarbons inhalation may lead to dysrhythmias and ‘sudden sniffing death’.Their

chronic abuse may lead to cereral atrophy, neuropsychiatric problems,peripheral neuropathy,kidney disease

Toluene may lead to type 4 renal tubular acidosis

Key Points

Poisoning can occur from accidental exposure (often younger children) or deliberate exposure (often from inhalation e.g. from “sniffing” or “chroming”)

Hydrocarbons affect CNS, respiratory and cardiovascular systems

They can cause rapid onset of CNS symptoms including CNS depression and seizures.

Ingestion of less than 5ml of pure essential oil can lead to significant CNS toxicity in children

Cardiac dysrhythmias are less common.

Aspiration of  even <1ml of Hydrocarbon can lead to chemical pneumonitis.

Inhalation injury may manifest up to 6 hrs after exposure

Gastric lavage,Emesis,Activated charcoal are contraindicated in hydrocarbon poisoning

Patients requiring assessment All patients with deliberate self-poisoning or significant accidental exposure

Any patient whose developmental age is inconsistent with accidental poisoning as non-accidental poisoning should be considered

Any symptomatic patient

Risk Assessment
History: 
Was exposure intentional or accidental? 
Dose
Type of compound 
Quantity ingested 
Duration of exposure in inhalation 
Co-ingestants (eg paracetamol)

Examination: 
Respiratory:
Coughing / gagging / choking indicates aspiration

Wheeze, tachypnoea, hypoxia, haemoptysis and pulmonary oedema are signs of evolving chemical pneumonitis.
Cardiovascular:
Dysrhythmias occur early in exposure(associated with halogenated hydrocarbon poisoning)
CNS:
CNS depression, coma and seizures may occur with large acute exposures. Onset is usually within 2 hours
GIT:
Nausea, vomiting and diarrhea Excessive burping, heartburn, epigastric pain

Investigations:

Asymptomatic children with small ingestions do not usually require investigation.

For children with more significant ingestions, or who are symptomatic:

12 lead ECG & cardiac monitoring for 4 hours

CBC, LFTs, ABGs CXR (if respiratory symptoms)

For all children with deliberate poisoning, perform further screening for co-ingestants
BSL Paracetamol level

Acute Management
Admit the patient
Counsel the parents
Get high risk consent
Get MLC.
1. Resuscitation 
Assess Airway , breathing and circulation
Intubate early for progressive CNS depression

Ventricular dysrhythmias: Commence advance life support

Intubate,mechanical ventilation, hyperventilate, correct hypoxia Correct electrolyte disturbances

2. Decontamination 
Activated charcoal is specifically contraindicated in hydrocarbon poisoning as they do not bind hydrocarbons and increase the risk of hydrocarbon aspiration

3.Seizures –

Benzodiazepines remain standard first line treatment.

Ongoing care and monitoring 
Asymptomatic children with normal vital signs should be observed for 6 hours post exposure before discharge 
Patients with milder respiratory or CNS symptoms should be admitted for a longer period of observation +/- supportive care
Chemical pneumonitis is managed supportively with Oxygen inhalation,nebulization with bronchodilators. Patient may require non invasive ventilation or intubation and mechanical ventilation with Standard mechanical ventilators or high frequency mechanical ventilators and if required extracorporeal membrane oxygenation.
Corticosteroids and prophylactic antibiotics are not indicated for chemical pneumonitis Fever and leukocytosis are common following aspiration with pneumonitis and does not indicate superadded bacterial infection – antibiotics should be withheld until there is objective evidence of bacterial infection

Discharge Criteria: 
Normal GCS 
Normal ECG 
No respiratory symptoms (cough, dyspnoea, wheeze) 
Normal observations including pulse oximetry 
Period of observation as above