Oxygen and helium gas mixtures for dyspnoea.

Purpose Of Review: Recent reports of the benefits of helium/oxygen gas mixtures (heliox) use for the relief of dyspnoea and exercise limitation have stimulated interest in the use of heliox in the palliation of dyspnoea especially in chronic obstructive pulmonary disease patients. With better understanding of the mechanistic causes of dyspnoea in these patients theoretical benefits of heliox have been suggested. This report considers the evidence to support this role and reviews the current position on heliox administration and use as a carrier gas for nebulization therapies.

Effects of NOS inhibition on the cardiopulmonary system and brain microvascular markers after intermittent hypoxia in rats.

We previously demonstrated that rats subjected to intermittent hypoxia (IH) by exposure to 10% O(2) for 4 h daily for 56 days in a normobaric chamber, developed pulmonary hypertension, right ventricular hypertrophy and wall-thickening in pulmonary arterioles, compared with normoxic (N) controls. These changes were greater in rats subjected to continuous hypoxia (CH breathing 10% O(2) for 56 days). Cerebral angiogenesis was demonstrated by immunostaining with glucose transporter 1 (GLUT1) antibody, in viable vessels, in CH and to a lesser degree in IH.

The effect of helium and oxygen on exercise performance in chronic obstructive pulmonary disease: a randomized crossover trial.

Rationale: Breathing supplemental oxygen reduces breathlessness during exercise in patients with chronic obstructive pulmonary disease (COPD). Replacing nitrogen with helium reduces expiratory flow resistance and may improve lung emptying. Combining these treatments should be independently effective.

Hypoxia of sleep apnoea: cardiopulmonary and cerebral changes after intermittent hypoxia in rats.

Sleep apnoea (SA) is common, especially in elderly people. In severe cases, arterial P(O2) may be lowered for a third or more in a night of sleep. To simulate the degree and duration of severe SA we exposed rats in a normobaric environmental chamber to 10% O(2) for 4h daily for 56 days (intermittent hypoxia: IH group) and compared them with rats continuously exposed for 8 weeks (continuous hypoxia: CH group) and control rats breathing room air (normoxic: N group).

A double-blind, randomised, controlled Phase II trial of Heliox28 gas mixture in lung cancer patients with dyspnoea on exertion.

Helium has a low density and the potential of reducing the work of breathing and improving alveolar ventilation when replacing nitrogen in air. A Phase II, double-blind, randomised, prospective, controlled trial was undertaken to assess whether Heliox28 (72% He/28% O(2)) compared with oxygen-enriched air (72% N(2)/28% O(2)) or medical air (78.9% N(2)/21.