ACMT Toxicology Visual Pearls: Abnormal Brain Imaging

Answer: 5 – hydrogen peroxide

Discussion

The brain MR images above show evidence of multifocal infarcts. This has been to shown to occur with hydrogen peroxide ingestion.

Hydrogen peroxide has been used commercially since the late 19th century in detergents and bleach because of its oxidizing properties.¹ The household product typically available has a concentration of 3%. More recently, highly concentrated (up to 35%) hydrogen peroxide has been sold in health food stores under the supposed benefit of hyper-oxygenation.^2–4

At room temperature, hydrogen peroxide is a clear liquid and can easily be mistaken for water and thereby accidentally ingested. Concentrated hydrogen peroxide ingestion can result in the formation of oxygen gas bubbles in the blood stream leading to cerebral gas embolism with diffuse, multifocal infarcts, affecting both gray and white matter.^1–4

Hydrogen peroxide ingestion results in tissue injury via 3 mechanisms:

1. Corrosive injury
2. Gas formation
3. Lipid peroxidation

Oxygen gas bubbles form in the blood stream when the oxygen solubility of the blood is exceeded. While hydrogen peroxide exposure at low concentrations tends to be more associated with gastrointestinal symptoms such as nausea and vomiting, ingestion of hydrogen peroxide with a concentration >10% is often associated with more severe outcomes.^1–6

Bedside Pearls

• Early symptoms: Nausea, vomiting, hematemesis, pain from gastric distention due to gas formation, mucosal burns, and stridor¹
• Signs and symptoms of embolic events: Altered mental status, seizure, focal neurologic deficit, respiratory distress, hypoxia, ECG changes, elevated troponin, and hemodynamic instability
• Labs: CBC, ABG, ECG²
• Imaging: Abdominal x-ray can assess for perforation, if suspected. CT imaging of head, chest, abdomen/pelvis can reveal gas emboli.³ To assess for cerebral infarcts, an MRI is often performed after initial management
• Treatment: Aggressive airway management is indicated, as clinical deterioration can be rapid. Hyperbaric oxygen therapy may be beneficial in the acute phase, and should be considered in patients with evidence (clinical or radiographic) of gas embolism.^2–6