Medical gas therapy

[1] In adults nitric oxide can be used in treating pulmonary hypertension with acute respiratory distress syndrome.

The U.S. Food and Drug Administration has been approved the use of nitric oxide in term and near-term (greater than 34 weeks' gestation age) neonates with hypoxic respiratory failure with clinical or echocardiographic evidence of pulmonary hypertension.

[6] Regular arterial blood gas tests needed to assess the response to the therapy and signs of toxicity.

If there is an evidence that nitric oxide works the same dose would be used till the hypoxemia and pulmonary hypertension resolved.

When the hypoxemia and pulmonary hypertension resolved titration or slowly weaning of the nitric oxide initiates.

Abrupt discontinuation of nitric oxide may lead to compromised oxygenation and pulmonary hypertension may rebound.

Nitric oxide with oxygen (O2) in combination produces another by-product chemical compound nitrogen dioxide (NO2).

Heliox generates less airway resistance than air and thereby requires less mechanical energy to ventilate the lungs.

Heliox's low density produces a lower Reynolds number and hence higher probability of laminar flow for any given airway.

In the small airways where flow is laminar, resistance is proportional to gas viscosity and is not related to density and so heliox has little effect.

In the large airways where flow is turbulent, resistance is proportional to density, so Heliox has a significant effect.

There is also some use of heliox in conditions of the medium airways (croup, asthma and chronic obstructive pulmonary disease).

Patients with these conditions may develop a range of symptoms including dyspnea (breathlessness), hypoxemia (below-normal oxygen content in the arterial blood) and eventually a weakening of the respiratory muscles due to exhaustion, which can lead to respiratory failure and require intubation and mechanical ventilation.

[11] Heliox has also found utility in the weaning of patients off mechanical ventilation, and in the nebulization of inhalable drugs, particularly for the elderly.