Respiratory physiology & neurobiology
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Respir Physiol Neurobiol · Nov 2007
Randomized Controlled Trial Clinical TrialEffect of sildenafil on hypoxia-induced changes in pulmonary circulation and right ventricular function.
Hypoxia leads to pulmonary vasoconstriction in healthy men. However, the consequences on right ventricular function are not known. The effects of hypoxia on systolic pulmonary artery pressure (sPAP) and right ventricular function index (TEI) were assessed by Doppler echocardiography. ⋯ At 5245 m sPAP was 29.1(1.7) and TEI was 0.43(0.05) in the placebo group, while in the sildenafil group, both sPAP and TEI were reduced to 22(1.5) mm Hg and 0.23(0.03) (each p<0.005), respectively. We conclude that in healthy individuals, exposure to acute hypoxia and sojourns at high altitude result in a small but significant increase in sPAP accompanied by an impairment of right ventricular function. Sildenafil significantly decreases sPAP and improves right ventricular function.
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Acute respiratory distress syndrome (ARDS) and its milder form acute lung injury (ALI) may result from various diseases and situations including sepsis, pneumonia, trauma, acute pancreatitis, aspiration of gastric contents, near-drowning etc. ALI/ARDS is characterized by diffuse alveolar injury, lung edema formation, neutrophil-derived inflammation, and surfactant dysfunction. ⋯ Changed concentrations of individual markers may suggest injury or activation of the specific types of lung cells-epithelial or endothelial cells, neutrophils, macrophages, etc.), and thereby help in diagnostics and in evaluation of the patient's clinical status and the treatment efficacy. This chapter reviews various biomarkers of acute lung injury and evaluates their usefulness in diagnostics and prognostication of ALI/ARDS.
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Respir Physiol Neurobiol · Nov 2013
ReviewRespiration following spinal cord injury: evidence for human neuroplasticity.
Respiratory dysfunction is one of the most devastating consequences of cervical spinal cord injury (SCI) with impaired breathing being a leading cause of morbidity and mortality in this population. However, there is mounting experimental and clinical evidence for moderate spontaneous respiratory recovery, or "plasticity", after some spinal cord injuries. ⋯ While the extent of spontaneous recovery remains limited, it is possible that enhancing or facilitating neuroplastic mechanisms may have significant therapeutic potential. The next generation of treatment strategies for SCI and related respiratory dysfunction should aim to optimize these recovery processes of the injured spinal cord for lasting functional restoration.
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Respir Physiol Neurobiol · Jun 2014
Randomized Controlled TrialAntagonism of substance P and perception of breathlessness in patients with chronic obstructive pulmonary disease.
The objective of this study was to investigate whether substance P, an excitatory neuropeptide, modulates the perception of breathlessness by administering aprepitant, a selective antagonist that blocks neurokinin (NK)-1 receptor signaling. Individual targeted resistive load breathing (RLB) was used to provoke breathlessness. In Study 1, sixteen patients (age, 70±6 years) with chronic obstructive pulmonary disease (COPD) reported similar ratings of breathlessness during RLB between oral aprepitant (125mg) and placebo. ⋯ Nine patients with COPD reported comparable breathlessness ratings during RLB between aprepitant and placebo. Our results do not support a role for the substance P-NK-1 pathway in the perception of breathlessness in patients with COPD. With selective antagonism of NK-1 signaling, there was co-transmission of substance P and beta-endorphin neuropeptides.
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Respir Physiol Neurobiol · Sep 2013
ReviewThe impact of spinal cord injury on breathing during sleep.
The prevalence of sleep disordered breathing (SDB) following spinal cord injury (SCI) is considerably greater than in the general population. While the literature on this topic is still relatively small, and in some cases contradictory, a few general conclusions can be drawn. ⋯ It is not yet possible to pinpoint a "primary factor" which will predispose an individual with SCI to SDB, and the underlying mechanisms may change during progression from acute to chronic injury. Given the prevalence and potential health implications of SDB in the SCI population, we suggest that additional studies aimed at defining the underlying mechanisms are warranted.