Respiratory physiology & neurobiology
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Respir Physiol Neurobiol · Dec 2011
On the crucial ventilatory setting adjustment from two- to one-lung ventilation.
Lung mechanics, histology, oxygenation and type-III procollagen (PCIII) mRNA were studied aiming to evaluate the need to readjust ventilatory pattern when going from two- to one-lung ventilation (OLV). Wistar rats were assigned to three groups: the left lung was not ventilated while the right lung received: (1) tidal volume (V(T))=5 ml/kg and positive end-expiratory pressure (PEEP)=2 cm H(2)O (V5P2), (2) V(T)=10 ml/kg and PEEP=2 cm H(2)O (V10P2), and (3) V(T)=5 ml/kg and PEEP=5 cm H(2)O (V5P5). ⋯ Although high V(T) prevented hypoxemia and maintained a higher specific compliance than V5P2, a morphologically inhomogeneous parenchyma and higher PCIII expression resulted. In conclusion, the association of low V(T) and an adequate PEEP level could be useful to maintain arterial oxygenation without inducing a possible inflammatory/remodeling response.
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Respir Physiol Neurobiol · Sep 2011
ReviewInflammatory pathways in children with insufficient or disordered sleep.
Sleep is not only an essential physiological function, but also serves important roles in promoting growth, maturation, and overall health of children and adolescents. There is increasing interest regarding the impact of sleep and its disorders on the regulation of inflammatory processes and end-organ morbidities, particularly in the context of metabolic and cardiovascular diseases (CVD) and their complications. Obstructive sleep apnea syndrome (OSAS) is an increasingly common health problem in children, and in the last decade, the emergence of increasing obesity rates has further led to remarkable increases in the prevalence of OSAS, along with more prominent neurocognitive, behavioral, cardiovascular and metabolic morbidities. ⋯ To this effect, it would appear that OSAS could be viewed as a chronic, low-grade inflammatory disorder. Furthermore, the concurrent presence of obesity and OSAS poses a theoretically increased risk of OSAS-related complications. In this review, we will critically review the current state of research regarding the impact of insufficient and disrupted sleep and OSAS on the immune processes and inflammatory pathways that underlie childhood OSAS as a distinctive systemic inflammatory condition in children, and will explore potential interactions between OSAS and obesity.
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Respir Physiol Neurobiol · Sep 2011
ReviewCongenital central hypoventilation syndrome and desogestrel: a call for caution: addendum to "C. Straus, H. Trang, M.H. Becquemin, P. Touraine, T. Similowski, Chemosensitivity recovery in Ondine's curse syndrome under treatment with desogestrel" [Respir. Physiol. Neurobiol. 171 (2010) 171-174].
Patients suffering from congenital central hypoventilation syndrome (CCHS) depend on mechanical ventilation during sleep, from birth and throughout life. They lack CO₂-chemosensitivity. ⋯ Desogestrel should not be prescribed to CCHS patients with a respiratory purpose until the results of a pending clinical trial (clinicaltrials.gov. NCT01243697) are available.
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Respir Physiol Neurobiol · Sep 2011
Comparative StudyTime course of lung inflammatory and fibrogenic responses during protective mechanical ventilation in healthy rats.
This study aimed to assess pulmonary inflammatory and fibrogenic responses and their impact on lung mechanics and histology in healthy rats submitted to protective mechanical ventilation for different experimental periods. Eighteen Wistar rats were randomized to undergo open lung-mechanical ventilation (OL-MV) for 1, 6 or 12 h. Following a recruitment maneuver, a decremental PEEP trial was performed and PEEP set according to the minimal respiratory system static elastance. ⋯ A moderate inflammatory response was observed with a distinct peak at 6h. Compared to unventilated controls, type I procollagen mRNA expression was decreased at 1 and 12h, while type III procollagen expression decreased throughout the 12h experimental period. In conclusion, OL-MV in healthy rats yielded overinflation after 6 h even though respiratory elastance and gas-exchange were preserved for up to 12 h.
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Respir Physiol Neurobiol · Aug 2011
Effects of different forms of dyspnoea on pain perception induced by cold-pressor test.
Although dyspnoea has been shown to attenuate pain, whether different forms of dyspnoea exert a similar inhibitory effect on pain has never been tested. We examined the effects of two different forms of dyspnoea, i.e., "air hunger" sensation (AIR HUNGER) and "work/effort" sensation (WORK/EFFORT), on pain induced by a cold-pressor test. ⋯ Both AIR HUNGER and WORK/EFFORT caused an increase in PTT and an increase in PET or a decrease in maximal pain VAS. Our findings suggest that AIR HUNGER and WORK/EFFORT exert a similar analgesic effect although the WORK/EFFORT-induced analgesia was slightly more effective.