What are the potential harmful effects of inhaling helium?

Potential Harmful Effects of Inhaling Helium

Inhaling helium can cause asphyxiation and death by displacing oxygen needed for normal respiration, with risks ranging from temporary dizziness and syncope to fatal hypoxia depending on concentration and duration of exposure. 1

Mechanism of Harm

Helium causes harm through several mechanisms:

• Oxygen displacement: As an inert gas, helium displaces oxygen in the lungs, leading to tissue hypoxia 1
• Rapid onset: Effects can occur quickly as helium is colorless, odorless, and provides no physiological warning signs 2
• No biological role: Helium plays no biological role in the human body and is normally found only in trace amounts in human blood 1

Clinical Manifestations of Helium Inhalation

Mild to Moderate Exposure

• Temporary voice changes (high-pitched, squeaky voice) - most common benign effect
• Dizziness/lightheadedness (13.7% of ED visits) 2
• Syncope (68.6% of ED visits) 2
• Non-concussion head injuries (28.1% of ED visits) from falls after syncope 2
• Contusions/abrasions (12.2% of ED visits) 2
• Concussions (10.8% of ED visits) 2

Severe Exposure

• Asphyxiation leading to unconsciousness
• Hypoxic brain injury
• Death due to oxygen deprivation 1, 3

Risk Factors for Severe Outcomes

• Confined spaces: Inhaling helium in enclosed spaces increases risk of severe hypoxia
• Direct delivery methods: Using masks, bags, or other delivery systems that limit air mixing
• High concentration exposure: Pure helium presents greater risk than diluted mixtures
• Duration of exposure: Longer exposure increases risk of severe outcomes
• Intentional misuse: Deliberate inhalation for suicide has been documented in multiple case reports 3, 4, 5

Special Considerations

Medical Use of Helium (Heliox)

When used medically as heliox (helium-oxygen mixture), safety parameters include:

• Proper oxygen concentration (typically 70:30 helium to oxygen ratio) 6
• Medical supervision
• Appropriate delivery systems

The British Thoracic Society notes that heliox has limited clinical utility and is not recommended for routine use in most respiratory conditions due to:

• No reduction in mortality or need for mechanical ventilation 7
• No reduction in rates of intubation or length of mechanical ventilation in AECOPD or asthma 6
• High cost compared to standard oxygen-air mixtures 7

Emergency Management of Helium Exposure

For accidental or recreational helium exposure:

1. Remove the person from the helium source immediately
2. Provide fresh air
3. Administer supplemental oxygen if available
4. Position unconscious patients in recovery position
5. Begin CPR if no pulse or respiration
6. Seek emergency medical attention for any symptoms beyond temporary voice changes

Prevention

• Store helium tanks securely away from children
• Educate about dangers of recreational helium inhalation
• Supervise children around helium-filled balloons
• Use only medical-grade heliox mixtures under proper supervision for therapeutic purposes

Pitfalls in Recognition and Management

• Helium inhalation injuries may be underreported as most patients (98.3%) are treated and released from emergency departments 2
• Forensic detection of helium is challenging and requires special collection techniques and gas chromatography methods 3, 5
• The increasing availability of information about helium inhalation for self-harm on the internet may contribute to increased incidence 3, 4

Helium inhalation, while seemingly harmless for brief voice alterations, carries significant risks of hypoxia and asphyxiation that can lead to injury or death, particularly with prolonged or high-concentration exposure.