Heliox Therapy: A Comprehensive Overview (2024)

Heliox therapy is a medical treatment that utilizes a mixture of helium and oxygen, known as heliox, to aid in the management of various respiratory conditions.

This article provides an overview of heliox therapy, its applications, and the ongoing research in the field of respiratory care.

What is Heliox?

Heliox is a gas mixture composed of helium and oxygen. Helium is present in the lower atmosphere in small quantities (0.0005%), but when mixed with oxygen, it forms a gas mixture with a density nearly six times lower than atmospheric air.

This low density and high thermal conductivity make heliox a valuable tool in respiratory medicine. Heliox gas mixtures are known to be non-toxic, non-carcinogenic, and have no lasting effects on any human organs.

How Does Heliox Work?

The lower density of heliox results in significantly lower turbulence, particularly in the more distal portions of the lung. This effect translates to a greater proportion of laminar flow and lower overall airway resistance.

The decreased turbulence effect results in increased flow rates by up to 50% during heliox inhalation. This decreased turbulence remained evident even when airflow was restricted, as in the case of obstructive lung disease.

Indications for Heliox Therapy

Heliox therapy is primarily used for the treatment of the following conditions:

• Upper airway obstruction
• Chronic obstructive pulmonary disease (COPD)
• Asthma exacerbation
• Severe respiratory failure
• Acute respiratory distress syndrome (ARDS)
• Laryngeal obstruction
• Subglottic stenosis
• Acute vocal cord dysfunction
• Bilateral vocal cord paralysis
• Croup
• Pneumonia
• Bronchiolitis
• Endotracheal and endobronchial disease
• Mediastinal mass
• Congenital diaphragmatic hernia (CDH)
• Nebulized drug delivery
• Pulmonary rehabilitation
• Improved exercise performance
• Pulmonary function testing

The major benefit of heliox comes from its lower density and improvement in flow dynamics. It has also demonstrated usefulness in obstructive lung diseases, such as asthma and COPD, as a vehicle for better deposition of bronchodilators.

Heliox has been associated with a faster improvement of respiratory rate, acidosis, hypercapnia, and encephalopathy. Its use has also shown a shorter duration of mechanical ventilation and ICU stay.

These benefits are all possibly due to improved respiratory mechanics. It has also been reported to promote a uniform distribution of bronchodilators in COPD and asthma.

Heliox Composition

The specific composition of heliox can vary depending on the clinical needs of the patient, but two common mixtures are:

• Heliox 80/20: This mixture contains 20% oxygen and 80% helium. It is often used for patients who do not require supplemental oxygen but could benefit from the reduced airway resistance and improved gas exchange that heliox provides.
• Heliox 70/30: This mixture contains 30% oxygen and 70% helium. It is typically used for patients who require a higher concentration of oxygen.

Note: The helium in the mixture reduces the overall oxygen content, so heliox should be used with caution in patients who require high concentrations of oxygen.

Clinical Applications of Heliox

Heliox has been used in a variety of clinical scenarios, particularly in the management of obstructive airway diseases. Here are some of the key applications:

• Airway Obstruction: Heliox was first used in the 1930s to relieve dyspnea in patients with asthma and laryngeal obstruction. Today, it is used in a variety of conditions that cause airway obstruction, such as acute vocal cord dysfunction, bilateral vocal cords paralysis, and intrinsic endotracheal and endobronchial diseases.
• Croup: Heliox has been used to treat severe croup in children, resulting in significant reductions in croup scores and avoiding the need for intubation.
• Chronic Obstructive Pulmonary Disease (COPD): Heliox has been shown to reduce the work of breathing in patients with COPD, improving exercise performance and reducing dynamic hyperinflation.
• Asthma: Randomized, placebo-controlled studies have shown that heliox can improve clinical asthma scores in children with acute asthma.
• pneumonia and Other Lower Airway Conditions: Heliox has been used in conditions involving lower airway obstruction, such as pneumonia, bronchiolitis, and cystic fibrosis.

Physiological Effects of Heliox

Heliox has unique physical properties that can have several physiological effects on the respiratory system, particularly in conditions where airflow is obstructed.

Here are some of the key physiological effects of heliox:

• Reduced Airway Resistance: The low density of heliox reduces the resistance to airflow, particularly in the small airways of the lungs. This can be particularly beneficial in conditions such as asthma or chronic obstructive pulmonary disease (COPD), where airway resistance is increased. By reducing airway resistance, heliox can decrease the work of breathing and potentially alleviate symptoms such as shortness of breath.
• Increased Laminar Flow: The low density and high thermal conductivity of heliox can change the nature of airflow in the lungs from turbulent to laminar, especially in the smaller airways. Laminar flow is smoother and less resistant to movement than turbulent flow, which can further reduce the work of breathing.
• Improved Gas Exchange: By reducing airway resistance and promoting laminar flow, heliox can improve the distribution of ventilation in the lungs. This can enhance gas exchange, potentially improving oxygenation and reducing carbon dioxide retention, especially in conditions like COPD or severe asthma.
• Enhanced Drug Delivery: The physical properties of heliox can enhance the delivery of aerosolized medications, such as bronchodilators, to the lungs. By reducing turbulence, heliox can help carry these medications deeper into the lungs, potentially making them more effective.
• Reduced Work of Breathing: By reducing airway resistance and improving gas exchange, heliox can significantly reduce the work of breathing. This can be particularly beneficial in conditions where the work of breathing is significantly increased, such as severe asthma, COPD, or respiratory distress syndrome.

Note: While heliox can have these beneficial physiological effects, it is not a treatment for the underlying disease. Rather, it is a supportive therapy that can help manage symptoms and improve the effectiveness of other treatments.

Heliox Contraindications

Heliox therapy is generally considered safe and has no specific contraindications based on the properties of the gas mixture itself.

However, there are certain situations where its use may not be appropriate or beneficial:

• High Oxygen Requirement: Patients who require a high concentration of oxygen may not be suitable candidates for heliox therapy. The helium in the mixture reduces the overall oxygen content, so heliox mixtures typically contain only 20% or 30% oxygen. If a patient requires a higher concentration of oxygen, other forms of therapy may be more appropriate.
• High-Pressure Ventilation: Heliox is less dense than air, which can make it less effective in situations where high-pressure ventilation is required. If a patient requires high-pressure mechanical ventilation, the use of heliox may not be beneficial.
• Lack of Availability or Cost: Heliox can be expensive and is not always readily available. In some cases, the potential benefits of heliox therapy may not outweigh the costs or logistical challenges associated with its use.

As always, the decision to use heliox therapy should be made by a healthcare professional based on a thorough evaluation of the patient’s condition, the potential benefits and risks of therapy, and the availability of resources.

Heliox Calculation

When administering heliox therapy, it’s crucial to accurately calculate the actual flow rate of the gas mixture. The composition of heliox can either be 80% helium and 20% oxygen (80/20) or 70% helium and 30% oxygen (70/30).

Each of these mixtures has a unique factor that is used for the calculation:

• Heliox 80/20 = 1.8
• Heliox 70/30 = 1.6

These factors are used to adjust the given flow rate to the actual flow rate that the patient receives. The formula for this calculation is:

Actual Flow Rate = Given Flow Rate x Heliox Factor

Here’s an example to illustrate this calculation:

Suppose a patient is receiving an 80/20% helium-to-oxygen mixture at a given flow rate of 10 L/min. To calculate the actual flow rate, you would use the factor for the 80/20 mixture, which is 1.8. Plugging these numbers into the formula gives:

Actual Flow Rate = 10 L/min x 1.8 = 18 L/min

So, in this case, the patient is actually receiving a flow rate of 18 L/min.

This calculation ensures that the patient receives the correct amount of heliox, taking into account the unique physical properties of the gas mixture.

Heliox vs. Nitric Oxide

Heliox and nitric oxide are both gases used in medical treatments, particularly for respiratory conditions, but they have different properties and uses.

Heliox

Heliox is a mixture of helium and oxygen. The low density of this mixture reduces airway resistance and promotes laminar flow in the lungs, which can decrease the work of breathing, improve gas exchange, and enhance the delivery of aerosolized medications.

Heliox is often used in the treatment of conditions that cause airway obstruction or increased work of breathing, such as asthma, chronic obstructive pulmonary disease (COPD), and croup.

Nitric Oxide

Nitric oxide (NO), on the other hand, is a potent vasodilator. When inhaled, it selectively dilates the pulmonary vessels, improving blood flow to well-ventilated areas of the lung and thereby improving oxygenation.

Inhaled nitric oxide (iNO) is commonly used in the treatment of neonates with persistent pulmonary hypertension of the newborn (PPHN) and adults with infant respiratory distress syndrome (IRDS).

In terms of their applications:

• Heliox is primarily used to reduce airway resistance and improve the delivery of inhaled medications in obstructive lung diseases.
• Nitric oxide is used to improve oxygenation in conditions characterized by pulmonary hypertension and hypoxic respiratory failure.

Note: The use of both heliox and nitric oxide should be guided by a healthcare professional, as both have specific indications and potential risks that need to be considered.

Heliox Conversion Chart

A heliox conversion chart is used to calculate the actual flow rate of Heliox delivered to the patient.

The chart typically includes the given flow rate (what the flow meter is set at) and the corresponding actual flow rate for both 80/20 and 70/30 Heliox mixtures.

Here’s an example of what a simplified Heliox conversion chart might look like:

Remember: The actual flow rate is calculated by multiplying the given flow rate by the Heliox factor (1.8 for 80/20 Heliox and 1.6 for 70/30 Heliox). This chart is a simplified version, and the actual flow rates may vary slightly due to factors such as temperature and pressure. Always refer to the specific guidelines provided by the manufacturer or healthcare institution.

Ongoing Research and Controversies

Despite the promising results, the use of heliox in routine practice remains controversial due to technical implications and high costs.

More research is needed to determine which patients may benefit most from heliox use, whether it is useful in combination with noninvasive mechanical ventilation or aerosol delivery, and what the best delivery system for heliox is.

FAQs About Heliox

What is Heliox Therapy?

Heliox therapy is a medical treatment that uses a mixture of helium and oxygen, known as heliox, to aid in the management of various respiratory conditions.

The unique physical properties of heliox, such as its low density and high thermal conductivity, make it a valuable tool in respiratory medicine.

What is Heliox 80/20 vs. 70/30?

Heliox 80/20 and Heliox 70/30 are mixtures of helium and oxygen used in medical treatments. Heliox 80/20 contains 80% helium and 20% oxygen, often used for patients who need reduced airway resistance and improved gas exchange but not high supplemental oxygen.

Heliox 70/30, with 70% helium and 30% oxygen, is for patients requiring a slightly higher oxygen concentration. The choice depends on the patient’s specific oxygen requirements and is determined by the healthcare provider.

What is the Mechanism of Action of Heliox Therapy?

The mechanism of action of heliox therapy is primarily based on the physical properties of the heliox gas mixture.

Heliox has a lower density than air, which reduces airway resistance and promotes laminar flow in the lungs, especially in the smaller airways.

This can decrease the work of breathing, improve gas exchange, and enhance the delivery of aerosolized medications to the lungs.

What Does Heliox Treat?

Heliox is used to treat a variety of conditions that cause airway obstruction or increased work of breathing.

These include acute and chronic conditions such as asthma, chronic obstructive pulmonary disease (COPD), croup in children, and other conditions involving lower airway obstruction like pneumonia, bronchiolitis, and cystic fibrosis.

It’s also used in cases of vocal cord dysfunction and bilateral vocal cord paralysis.

What Mask is Used for Heliox?

Heliox is typically administered using a nonrebreather mask or a Venturi mask. The choice of mask depends on the patient’s condition and the specific clinical scenario.

It’s important to ensure that the mask fits properly to prevent leakage and maximize the benefits of heliox therapy.

How Do You Administer Heliox Therapy?

Heliox therapy is administered through inhalation. The heliox gas mixture is typically delivered using a nonrebreather mask or a Venturi mask, as mentioned above.

The specific concentration of helium and oxygen in the mixture can vary depending on the patient’s needs, but a common mixture is 80% helium and 20% oxygen. The flow rate is adjusted to ensure that the patient’s oxygen needs are met.

When is Heliox Therapy Indicated for Asthma?

Heliox therapy is indicated for asthma when conventional treatments are not effective, or when the patient’s condition is severe. It can be particularly beneficial in cases of severe asthma exacerbation where there is significant airway obstruction.

Heliox can reduce airway resistance, improve gas exchange, and enhance the delivery of aerosolized medications, potentially improving symptoms and outcomes in these patients.

However, the decision to use heliox therapy should be made on a case-by-case basis, considering the patient’s overall condition and response to other treatments.

When is Heliox Therapy Indicated for Croup?

Heliox therapy is indicated for severe cases of croup, a common respiratory condition in children characterized by inflammation and swelling of the airway.

The low density of heliox can reduce airway resistance and improve airflow, potentially alleviating the stridor and breathing difficulties associated with croup.

However, heliox is typically used when standard treatments, such as corticosteroids and nebulized epinephrine, are not effective or the child’s condition is severe.

Final Thoughts

Heliox therapy is a valuable tool in the management of various respiratory conditions. Its unique properties, such as low density and high thermal conductivity, allow for reduced airway resistance, improved gas exchange, and enhanced delivery of aerosolized medications.

While it has proven beneficial in treating conditions like asthma, COPD, and severe croup, its use remains subject to ongoing research and clinical judgment.

Despite some challenges, such as cost and technical implications, heliox therapy holds promise for improving patient outcomes in a range of clinical scenarios, underscoring the need for continued exploration and understanding of its potential applications.