Heliox
Administration
- Type: Medical gas, Bronchodilator adjunct
- Dosage Forms: Premixed gas cylinders (typically 80:20 or 70:30 helium:oxygen)
- Routes of Administration: Inhaled (face mask or non-rebreather)
- Common Trade Names: Heliox (generic)
Adult Dosing
- 80:20 heliox (80% helium, 20% oxygen): preferred for maximum benefit; use when FiO2 requirements are low
- 70:30 heliox (70% helium, 30% oxygen): use when higher FiO2 is needed
- Administer continuously via non-rebreather mask or tight-fitting face mask
- Can be used as driving gas for nebulized medications (set flow to 11-15 L/min)
- Effect is immediate; benefit lost when removed
Pediatric Dosing
- Same concentrations as adult (70:30 or 80:20)
- Delivered via tight-fitting mask appropriate to size
Special Populations
Pregnancy Rating
- Safe; no systemic absorption
Lactation risk
- Safe; no systemic absorption
Renal Dosing
- Adult: No adjustment needed
- Pediatric: No adjustment needed
Hepatic Dosing
- Adult: No adjustment needed
- Pediatric: No adjustment needed
Contraindications
- Hypoxemia requiring FiO2 >30-40% (limits helium concentration below therapeutic threshold)
- Need for high-flow supplemental oxygen
- Pneumothorax (theoretical concern regarding gas trapping)
Adverse Reactions
Serious
- Hypoxia (if oxygen concentration insufficient for patient needs)
Common
- Voice change (higher pitch due to helium)
- Feeling of dyspnea (lower gas density feels different)
Pharmacology
- Half-life: N/A (inert gas, not metabolized)
- Metabolism: None; helium is biologically inert
- Excretion: Eliminated via exhalation
Mechanism of Action
- Helium is less dense than nitrogen (1/7th the density)
- Reduces gas mixture density, converting turbulent airflow to laminar flow in narrowed airways
- Decreases airway resistance and work of breathing
- Does not treat underlying pathology — serves as bridge therapy while definitive treatments take effect
Comments
- Temporizing measure only — does not treat the underlying cause of airway obstruction
- Most effective when obstruction is in large/central airways (upper airway obstruction, post-extubation stridor)
- Less effective for peripheral small airway disease
- Clinical use in asthma is controversial; evidence is mixed
- Better evidence for upper airway obstruction (croup, tracheal tumors, post-extubation stridor)
- Requires tight-fitting mask delivery system; entrainment of room air negates benefit
- Cannot be reliably delivered via nasal cannula
- Pulse oximetry readings may be inaccurate during heliox use
- Can improve nebulizer drug delivery to distal airways when used as driving gas
Indications by Condition
The following table is automatically generated from disease/condition pages across WikEM.