Effects of Heliox in Stable COPD Patients at Rest and during Exercise

Therapeutic gases used in balneotherapy and rehabilitation medicine - scientific relevance in the last ten years (2011 – 2020) - Synthetic literature review

ABSTRACT: Background. The medical relevance of therapeutic gases can range from use in burns and stroke victims to hypoxia therapy in children. However, medical gases such as oxygen, hydrogen, helium and xenon have recently come under increased exploration for their potential therapeutic use on various brain disease states, including traumatic brain injuries, hypoxia-ischemia and, cerebral hemorrhages. Objective. This synthetic review aims to rigorously select related articles and identify within their content the main possible uses of therapeutic gases and physiological mechanisms. The objective of this article is to present the various therapeutic mechanisms that have been proposed in the current literature and the medical relevance of various therapeutic gases used in balneotherapy or medical rehabilitation. Methods. To elaborate our synthesis review, we have searched for relevant open access articles in 6 international databases: Cochrane, Elsevier, NCBI/PubMed, NCBI/PMC, PEDro, and ISI Web of Knowledge/Science, published from January 2011 until December 2020. The contextually quested keywords combinations/ syntaxes used specified on this page. The eligible articles were analyzed in detail regarding pathologies addressed by therapeutic gases. All articles with any design (reviews, randomized controlled trials, non-randomized controlled trials, case-control studies, cross-sectional studies), if eligible according to the above-mentioned selection methodology, containing in the title or abstract the above-mentioned combinations, were included in the analysis. Articles were excluded in the second phase if they did not reach the relevance criterion. Results. Our search identified, first, 225 articles. After eliminating the duplicates, remained 180 articles. In the second phase, we applied a relevance criterion. Although our team - including the authors of this paper – have quite long and consistent expertise in achieving systematic literature reviews, the marked heterogeneity of both the item composing the subject we have approached and inherently the wase of presentations in the respective quite vast and diverse domain of medical gases, prevented us to fulfil, at least regarding this initial work, a systematic literature review. Instead, we succeeded to make a hopefully interesting and valuable narrative synthetic-related literature review. At the end of the second phase, 63 articles passed the relevance criterion and were included in this synthetic review. Conclusions. Therapeutic gases are not fully understood and used adequately for sanogenic or medical purposes. More research is needed to fully understand the mechanisms and importance of therapeutic gases. The link between balneotherapy and medical rehabilitation regarding the usage of therapeutical gases emphasises the unity for this medical speciality. Keywords: "Therapeutic gas"/ "Oxygen therapy"/ "Carbon dioxide"/ "CO2 therapy"/ "Carbon monoxide"/ "Mofette"/ "Hydrogen Sulfide"/ "H2S"/ "Helium"/ "Xenon"/ "Ozone therapy"/ "Radon"/ "Hydrogen therapy"/ "Nitric oxide"/ "Heliox" AND "Rehabilitation".

Heliox administration in anesthetized rabbits with spontaneous inspiratory flow limitation

We investigated the effects of heliox administration (80% helium in O₂) on tidal inspiratory flow limitation (tIFL) occurring in supine anesthetized spontaneously breathing rabbits, regarded as an animal model of obstructive apnea-hypopnea syndrome. 22 rabbits were instrumented to record oro-nasal mask flow, airway opening, tracheal and esophageal pressures, and diaphragm and genioglossus electromyographic activities while breathing either room air or heliox, and, in 12 rabbits, also during the application of continuous positive airway pressure (CPAP; 6 cmH₂O). For the group, heliox increased peak inspiratory flow, ventilation (18 ± 11%), peak inspiratory tracheal and dynamic transpulmonary pressures, but in no animal eliminated tIFL, as instead CPAP did in all. Muscle activities were unaffected by heliox. In the presence of IFL the increase in flow with heliox (ΔV̇ifl) varied markedly among rabbits (2 to 49%), allowing the distinction between responders and non-responders. None of the baseline variables discriminated responders and non-responders. However, fitting the Rohrer equation (R = K₁ + K₂V̇) to the tracheal pressure-flow relationship over the first 0.1 s of inspiration while breathing air allowed such discrimination on the basis of larger K₂ in responders (0.005 ± 0.002 versus 0.002 ± 0.001 cmH₂O·s²·ml^-2; P < 0.001), suggesting a corresponding difference in the relative contribution of laminar and turbulent flow. The differences in ΔV̇ifl between responders and non-responders were simulated by modeling the collapsible segment of the upper airways as a non-linear resistor and varying its pressure-volume curve, length, and diameter, thus showing the importance of mechanical and geometrical factors in determining the response to heliox in the presence of tIFL.NEW & NOTEWORTHY In an obstructive sleep apnea rabbit model, heliox never abolishes tidal inspiratory flow limitation (IFL), but increases inspiratory flow and tidal volume, substantially in some and nearly nil in other animals. Positive response to heliox cannot be predicted on the basis of breathing pattern characteristics or upper airway resistance that preceded IFL onset, but is related to the mechanical and geometrical features of upper airway collapsible segment, as indicated by model simulation.

Mechanical ventilation in patients with chronic obstructive pulmonary disease and bronchial asthma

Chronic obstructive pulmonary disease (COPD) and bronchial asthma often complicate the surgical patients, leading to post-operative morbidity and mortality. Many authors have tried to predict post-operative pulmonary complications but not specifically in COPD. The aim of this review is to provide recent evidence-based guidelines regarding predictors and ventilatory strategies for mechanical ventilation in COPD and bronchial asthma patients. Using Google search for indexing databases, a search for articles published was performed using various combinations of the following search terms: ‘Predictors’; ‘mechanical ventilation’; COPD’; ‘COPD’; ‘bronchial asthma’; ‘recent strategies’. Additional sources were also identified by exploring the primary reference list.