View source for 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==
===[[Drug pregnancy categories|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 [[acute asthma exacerbation|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.''
{{#ask:[[Has DrugName::Heliox]]
|?Has Indication=Indication
|?Has Dose=Dose
|?Has Context=Context
|?Has Route=Route
|?Has Population=Population
|format=table
|headers=plain
|mainlabel=-
|sort=Has Indication
|limit=50
}}

==See Also==
*[[Acute asthma exacerbation]]
*[[Croup]]
*[[Upper airway obstruction]]
*[[COPD exacerbation]]

==References==
<references/>

[[Category:Pharmacology]]