[Specific effect of exercise training on depression in COPD patients]. / Impact spécifique du réentraînement à l'exercice sur les symptômes de dépression dans la broncho-pneumopathie chronique obstructive : expérience du Réseau insuffisance respiratoire de Lorraine.

INTRODUCTION: Depression is a common comorbidity in COPD patients, worsening their quality of life and their current level of physical activity. Respiratory rehabilitation is therefore highly recommended for COPD patients but only few of them have access to that kind of program. In real life, exercise training is often the only therapeutic activity provided to patients. METHODS: The aim of this study was to evaluate the specific effect of exercise training on the level of depression (using Beck Depression inventory short form (BDI-SF)) and quality of life in COPD patients [using the Saint George's Respiratory Questionnaire (SGRQ)]. Five hundred and fifteen COPD patients were enrolled in home-based exercise training programs. 421 programs were completed and the data was available for 182 patients (SGRQ, BDI-SF et TE) at T0 and T12. RESULTS: Dyspnoea (mMRC), SGRQ, BDI-SF scores and TE were significantly improved by the exercise training: mMRC 2,7±0,9 vs. 2,3±1,2; SGRQ 45±15 vs 34±18; BDI-SF 4,2±5,1 vs. 2,7±4,3; TE 6,4±5,4 vs. 17,2±12,8 respectively at T0 and T12. The improvement of TE was significantly correlated to that of the SGRQ scores (r=0,4; P<0,001) and of the BDI-SF scores (r=-0,24; P=0,001). CONCLUSION: This home-based exercise training program improved dyspnoea, quality of life, depression and exercise capacity. The improvement of the TE and BDI-SF scores were correlated.

[Guidelines for methacholine provocation testing]. / Recommandations pour le test de provocation bronchique à la méthacholine en pratique clinique, à partir de l'âge scolaire.

Bronchial challenge with the direct bronchoconstrictor agent methacholine is commonly used for the diagnosis of asthma. The "Lung Function" thematic group of the French Pulmonology Society (SPLF) elaborated a series of guidelines for the performance and the interpretation of methacholine challenge testing, based on French clinical guideline methodology. Specifically, guidelines are provided with regard to the choice of judgment criteria, the management of deep inspirations, and the role of methacholine bronchial challenge in the care of asthma, exercise-induced asthma, and professional asthma.

Sinusology.

This paper presents a brief history of the successive anatomical, physiological and pathophysiological concepts about the paranasal sinuses. Sinusology, the science of the paranasal sinuses, is founded on scientific work on the production of nitric oxide (NO) by the sinuses and on the evo-devo theory of their formation. The paranasal sinuses seem to develop after regression of the erythropoietic marrow in the maxillary, frontal and sphenoid bones and its replacement by cavities filled with gas, which escapes into the nasal fossae through the ostium. The sinus epithelium synthesizes NO continuously. The paranasal sinus cavities form a compartmentalized reservoir of NO, which is released discontinuously in boli after an opening of the ostium. Ostium opening can be induced by sound vibration, either internal (humming) or external (an acoustic vibration added to the in-breath). NO plays the role of an "aerocrine" messenger between the upper and lower respiratory tracts, reducing pulmonary vascular resistance and facilitating alveolar oxygen transfer into the bloodstream. Its physiological role in arterial blood oxygenation could be involved in speech and singing or be activated by physiological snoring during sleep. Rhinology, the science of the nose, in which the evo-devo concept distinguishes the respiratory and the olfactory nose, is now backed up by sinusology.

Effects of infusion of human methemoglobin solution following hydrogen sulfide poisoning.

RATIONALE: We have recently reported that infusion of a solution containing methemoglobin (MetHb) during exposure to hydrogen sulfide results in a rapid and large decrease in the concentration of the pool of soluble/diffusible H2S in the blood. However, since the pool of dissolved H2S disappears very quickly after H2S exposure, it is unclear if the ability of MetHb to "trap" sulfide in the blood has any clinical interest and relevance in the treatment of sulfide poisoning. METHODS: In anesthetized rats, repetition of short bouts of high level of H2S infusions was applied to allow the rapid development of an oxygen deficit. A solution containing MetHb (600 mg/kg) or its vehicle was administered 1 min and a half after the end of H2S intoxication. RESULTS: The injection of MetHb solution increased methemoglobinemia to about 6%, almost instantly, but was unable to affect the blood concentration of soluble H2S, which had already vanished at the time of infusion, or to increase combined H2S. In addition, H2S-induced O2 deficit and lactate production as well as the recovery of carotid blood flow and blood pressure were similar in treated and control animals. CONCLUSION: Our results do not support the view that administration of MetHb or drugs-induced methemoglobinemia during the recovery phase following severe H2S intoxication in sedated rats can restore cellular oxidative metabolism, as the pool of diffusible sulfide, accessible to MetHb, disappears rapidly from the blood after H2S exposure.

[Sleep and academic performance in young elite athletes]. / Sommeil et résultats scolaires chez les jeunes sportifs de haut niveau.

RATIONALE: In French law (Code du Sport), the status of elite athlete is allowed for young athletes beginning at the age of 12 years. For these young athletes, the aim is to reach the highest level of performance in their sport without compromising academic performance. Training time is therefore often substantial and sleep patterns appear to play a key role in performance recovery. The aim of this study was to assess sleep patterns and their effects on academic performance in young elite athletes. MATERIAL AND METHODS: Sleep patterns were assessed using questionnaires completed during a specific information-based intervention on sports medicine topics. The academic performance of young elite athletes was assessed by collecting their grades (transmitted by their teachers). RESULTS: Sleep patterns were assessed for 137 young elite athletes (64 females, 73 males; mean age, 15.7 years) and academic performance for 109 of them. Daily sleep duration during school periods (8h22 ± 38 min) were shorter compared to holidays and week-ends (10h02 ± 1h16, P<0.0001). Fifty-six athletes (41 %) subjectively estimated their sleep quality as poor or just sufficient. Poor sleep quality was correlated with poor academic performance in this specific athlete population. DISCUSSION: Sleep is the most important period for recovery from daily activity, but little information is available regarding the specific population of young elite athletes. The results reported herein suggest insufficiency (quantitatively and qualitatively) of sleep patterns in some of the young athletes, possibly leading to detrimental effects on athletic performance. Moreover, disturbed sleep patterns may also impact academic performance in young elite athletes. CONCLUSION: Teachers, athletic trainers, physicians, and any other professionals working with young elite athletes should pay particular attention to this specific population regarding the possible negative repercussions of poor sleep patterns on academic and athletic performance.

Early incidence of occupational asthma is not accelerated by atopy in the bakery/pastry and hairdressing sectors.

SETTING: Occupational asthma (OA) is most likely to develop in the very early years of exposure. OBJECTIVE: To describe the early incidence of OA among bakers/pastry-makers (BP) and hairdressers and to explore the role of atopy. DESIGN: Following a retrospective follow-up design, subjects were invited to undergo telephone interviews. Those who declared work-related respiratory or rhinitis symptoms and a sample group of others were offered a medical visit for OA investigations. Data from interviews and from medical visits were used to estimate the incidence of OA according to increasing durations of exposure. RESULTS: A total of 866 subjects were interviewed (mean age 25.3 years, 43.8% females), of whom 282 underwent a medical visit. Total estimated incidence rates of 'confirmed or probable' OA during the first 12 years of exposure were high in BP (2.63 per 100 person-years [py]) and in hairdressers (0.58/100 py), particularly in the first 4 years. Atopy is a strong risk factor for incidence among BP but, irrespective of the occupational sector, it does not influence the timing of OA symptoms. CONCLUSION: OA symptoms occur soon after the start of exposure. Our results suggest that atopy does not precipitate the occurrence of symptoms in two different allergen exposure settings.

[Excessive daytime sleepiness. An epidemiological study based on a "sleep/breathing" questionnaire]. / Somnolence diurne excessive. Étude épidémiologique basée sur un questionnaire « sommeil/respiration ¼

BACKGROUND: A field survey used a "sleep-breathing" questionnaire to estimate the prevalence of the excessive daytime sleepiness in a sample of middle-aged males. METHODS: Eight hundred and fifty men aged 22 to 66 years agreed to answer a questionnaire and have anthropometric measurements. To the question on excessive daytime sleepiness, 90 subjects (10.8%) responded "often" or "almost always"; 740 gave a negative answer. RESULTS: The sleepy subjects were older and had a higher "central" weight. All the sleep-disturbed breathing symptoms and those suggesting sleep disturbances were more frequent in sleepy subjects. Sleepiness was significantly associated with sleep apnea and chronic bronchitis. Logistic regression identified six items independently associated with daytime sleepiness; there were three indirect indicators of sleepiness, age, a history of chronic bronchitis and disruptive movements during sleep. CONCLUSIONS: This epidemiologic study in a sample of active middle-aged males confirms the association of daytime sleepiness with a series of respiratory and non-respiratory sleep disturbances. The original findings are the role of a "central" obesity, the association with nightmares, and the role of chronic bronchitis as a determinant of daytime sleepiness.

Stimulus response latency of cough and expiration reflex depends on breathing in the rabbit.

Expiration reflex and cough may have distinct afferent pathways and/or central integrative mechanisms that may both result in different stimulus response latencies. A newly described method that uses a punctuate mechanical tracheal stimulus to provoke defensive ventilatory reflexes should allow the stimulus response latency to be calculated with reasonable accuracy. The aim of the study was to test whether cough and expiration reflex have different stimulus response latencies. Four hundred and sixty one mechanical tracheal stimulations (50-300 msec) were performed in 21 anesthetized, tracheotomized rabbits. Twenty three percent stimulations (108) provoked a cough reflex and 37% an expiration reflex (171). The individual mean stimulus response latency was computed for each reflex, calculated from stimulus onset to earliest detectable change in ventilatory flow. Cough reflex latency was significantly shorter in inspiration compared to expiration (257±19 msec vs 391±61 msec; p=0.01). In contrast, the expiration reflex latency was significantly shorter in expiration compared to inspiration (210±11 msec vs 329±29 msec, p=0.003). It is concluded that the within breath dependence of the difference in stimulus response latency between cough and expiration reflex is more likely to express different brainstem mechanisms but difference in afferent fibres may not be excluded.

Cough threshold and reactivity to mechanical stimulation of the trachea in the rabbit preliminary observations.

OBJECTIVES: The aim of the study was to characterise mechanically induced cough threshold and reactivity by exposing the trachea to stimuli of variable duration in rabbit. BACKGROUND: Long lasting mechanical stimulation is widely used in experimental protocols studying cough reflex. The cough threshold and reactivity to chemical agents is known to change due to e.g. airway inflammation but similar evidence for mechanical stimulation has not been reported. METHODS: The tracheal provocation was realized in two anesthetized tracheotomized rabbits with a rotating probe actuated by a small electrical motor with mechanical stimulus times (ST) lasting 50, 150, 300 and 600 ms. Cough reflex was evaluated from tidal volume and airflow signals. RESULTS: The incidence of cough reflex (single or multiple) increased from 8% (ST 50 ms) to 84% (ST 600 ms). With the lengthening of stimulus, the rate of multiple responses increases. CONCLUSION: The technique developed here may prove useful to standardize the protocols of mechanical cough in the experimental animal using an approach similar to chemical tussigenic agents. The cough threshold could be defined as minimal ST (STmin) capable to elicit 1 cough and cough reactivity obtained by interpolation as ST that provokes 50 % of cough responses (STso) (Tab. 1, Fig. 3, Ref. 27).

[Exercise-induced bronchoconstriction in non-asthmatic athletes]. / Bronchoconstriction induite par l'exercice sans asthme associé chez l'athlète: physiopathologie, diagnostic et prise en charge spécifique.

INTRODUCTION: A new clinical entity, exercise-induced bronchoconstriction (EIB), has been recently defined which describes bronchoconstriction occurring in association with exercise in susceptible non-asthmatic persons. STATE OF ART: There is considerable evidence that the pathogenesis of this condition is related to airway injury, due to prolonged hyperventilation and aggressive environmental factors. If the objective diagnostic tests are identical for the diagnosis of exercise induced asthma and EIB, the diagnoses are established differently, according to the high sensitivity of provocation by exercise "in the field" or the eucapnic voluntary hyperventilation provocation test. PERSPECTIVES: Current pharmacological treatment is based upon the inhalation of ß2-agonists prior to exercise, but to be granted permission to use them, athletes are required to provide documentation of objective evidence of EIB. Therefore, the diagnostic pathway in athletes is essential and respiratory physicians need to know the specific features of this new clinical entity. CONCLUSIONS: EIB distinct from the presence of asthma is prevalent in elite athletes and its determinants should be well known by their health care providers to assure an optimal management of this peculiar disease, in respect to drug doping regulations.

[Is a sedentary lifestyle a risk factor for sleep-related respiratory disturbance?]. / La sédentarité est-elle un facteur de risque de troubles respiratoires pendant le sommeil?

INTRODUCTION: This questionnaire-based epidemiological study was aimed at identifying possible sleep disturbance in a sample of active French males. METHODS: Eight hundred and fifty male subjects, aged 22 to 66 years, completed a structured sleep questionnaire supplemented by information about their life habits and medical history. The study compared the prevalence of positive responses between an "at risk" group of sedentary people (with no declared leisure exercise) and a control group of "exercising" subjects (with more than 5 hours of planned exercise weekly). RESULTS: Among the symptoms suggesting sleep-disordered breathing, only the question "Have you ever been told that you snore?" significantly separated the two groups. In addition, the sedentary group declared a history of treated hypertension significantly more often. CONCLUSIONS: The present survey identified only one item that differed significantly between a sedentary of men and an exercising group - a history of treated hypertension. The result may be explained by the limitations of a questionnaire survey and by the limited contrast in exercise practice: the "sedentary" subjects had an occupational labour demand (not quantified), and the control group had a relatively modest leisure physical activity.

The apneic threshold during non-REM sleep in dogs: sensitivity of carotid body vs. central chemoreceptors.

The relative importance of peripheral vs. central chemoreceptors in causing apnea/unstable breathing during sleep is unresolved. This has never been tested in an unanesthetized preparation with intact carotid bodies. We studied three unanesthetized dogs during normal sleep in a preparation in which intact carotid body chemoreceptors could be reversibly isolated from the systemic circulation and perfused. Apneic thresholds and the CO(2) reserve (end-tidal Pco(2) eupneic - end-tidal Pco(2) apneic threshold) were determined using a pressure support ventilation technique. Dogs were studied when both central and peripheral chemoreceptors sensed transient hypocapnia induced by the pressure support ventilation and again with carotid body isolation such that only the central chemoreceptors sensed the hypocapnia. We observed that the CO(2) reserve was congruent with4.5 Torr when the carotid chemoreceptors sensed the transient hypocapnia but more than doubled (>9 Torr) when only the central chemoreceptors sensed hypocapnia. Furthermore, the expiratory time prolongations observed when only central chemoreceptors were exposed to hypocapnia differed from those obtained when both the central and peripheral chemoreceptors sensed the hypocapnia in that they 1) were substantially shorter for a given reduction in end-tidal Pco(2), 2) showed no stimulus: response relationship with increasing hypocapnia, and 3) often occurred at a time (>45 s) beyond the latency expected for the central chemoreceptors. These findings agree with those previously obtained using an identical pressure support ventilation protocol in carotid body-denervated sleeping dogs (Nakayama H, Smith CA, Rodman JR, Skatrud JB, Dempsey JA. J Appl Physiol 94: 155-164, 2003). We conclude that hypocapnia sensed at the carotid body chemoreceptor is required for the initiation of apnea following a transient ventilatory overshoot in non-rapid eye movement sleep.

[Severe breathlessness in a patient presenting with chronic bronchitis]. / Dyspnée sévère chez un patient présentant une bronchite chronique.

INTRODUCTION: Dyspnoea is the major symptomatic complaint of patients with chronic obstructive pulmonary disease (COPD). Awareness of an unpleasant respiratory sensation, occurs through a complex system of ventilatory control where, as in pain perception, supra-bulbar structures play a major role. In the hyperventilation syndrome, dramatic episodes of dyspnea can occur without any change in peripheral afferent signals and thus do not predictably represent a real deterioration in pulmonary function in patients who also have COPD. CASE REPORT: We report the observation of a patient with GOLD stage 0 COPD who demonstrated a major limitation of daily activities due to supra-bulbar influences on respiratory control which triggered repetitive periods of hyperventilation and generated almost constant dyspnea. CONCLUSIONS: Hyperventilation syndrome can be difficult to diagnose in patients with respiratory disease, although, in most cases, the discrepancy between the severity of symptomatic complaint compared to the degree of alteration of lung function in combination with specific tests may suggest the diagnosis.

Response time and sensitivity of the ventilatory response to CO2 in unanesthetized intact dogs: central vs. peripheral chemoreceptors.

We assessed the speed of the ventilatory response to square-wave changes in alveolar P(CO2) and the relative gains of the steady-state ventilatory response to CO2 of the central chemoreceptors vs. the carotid body chemoreceptors in intact, unanesthetized dogs. We used extracorporeal perfusion of the reversibly isolated carotid sinus to maintain normal tonic activity of the carotid body chemoreceptor while preventing it from sensing systemic changes in CO2, thereby allowing us to determine the response of the central chemoreceptors alone. We found the following. 1) The ventilatory response of the central chemoreceptors alone is 11.2 (SD = 3.6) s slower than when carotid bodies are allowed to sense CO2 changes. 2) On average, the central chemoreceptors contribute approximately 63% of the gain to steady-state increases in CO2. There was wide dog-to-dog variability in the relative contributions of central vs. carotid body chemoreceptors; the central exceeded the carotid body gain in four of six dogs, but in two dogs carotid body gain exceeded central CO2 gain. If humans respond similarly to dogs, we propose that the slower response of the central chemoreceptors vs. the carotid chemoreceptors prevents the central chemoreceptors from contributing significantly to ventilatory responses to rapid, transient changes in arterial P(CO2) such as those after periods of hypoventilation or hyperventilation ("ventilatory undershoots or overshoots") observed during sleep-disordered breathing. However, the greater average responsiveness of the central chemoreceptors to brain hypercapnia in the steady-state suggests that these receptors may contribute significantly to ventilatory overshoots once unstable/periodic breathing is fully established.

Effect of exercise on lung-perfusion scanning in patients with bronchogenic carcinoma.

The aim of this study was to determine whether perfusion-scintillation scanning, used as a predictive pre-operative index of lung functionality in patients with lung cancer, is affected by the level of pulmonary blood flow (PBF). Twenty patients with primary lung cancer underwent spirometry and a radionuclide-perfusion scan (macroaggregated albumin particles labelled with 99mTechnetium) both at rest and during the last minute of a ramp-like increase in work rate until exhaustion. On average, the perfusion of the lung with the tumour was significantly reduced by the same magnitude at rest and during exercise (mean+/-SD: -9+/-6% versus -10+/-4% of the cardiac output), regardless of the extent of the tumour. However, subject-by-subject analysis revealed that in two patients, a larger decrease in the perfusion of the lung with the tumour was observed during exercise than at rest (-11% and -17%, respectively). This leads to an underestimation of predictive postoperative functional parameters if resting values are used in these patients. The use of perfusion scintigraphy at rest therefore gives a clear picture of the functionality of the lung before resection in most patients requiring surgery.

Control of breathing and muscle perfusion in humans.

Very brief and intense exercise triggers a biphasic metabolic and respiratory response with a second phase that occurs after the cessation of the muscular activity. The effects on minute ventilation (V(E)) produced by manipulation of the peripheral circulation in metabolically active muscles could thus be studied without the confounding effects of painful contractions. The second phase of breath-by-breath V(E) and pulmonary gas exchange responses to a brief change in work rate (400 W for 12 s) were studied in six healthy male subjects on four occasions (24 tests). An upper thigh cuff inflation was randomly applied either above or below the systolic blood pressure (200 or 90 Torr, respectively) for 90 s just after the cessation of the contractions prior to the delayed rise in pulmonary gas exchange (eight tests in each subject). Total occlusion produced a significant reduction in the delayed rise in V(E) (-29 +/- 3 %) which normally occurred 20-25 s after the cessation of the contractions. In contrast, cuff inflation at a level predominantly impeding venous return while partially maintaining the arterial supply reduced the rise in pulmonary gas exchange in similar proportion to that during total obstruction but with a slight but not significant reduction in ventilation (-9 +/- 5 %). V(E) during partial occlusion was if anything higher than in control tests with similar oxygen uptake (280 W), despite a higher blood pressure (BP) during occlusion (+7 Torr). It is concluded that the factors resulting from a reduction in venous return or from the involvement of the arterial baroreflex are not responsible for the changes in V(E) produced by the obstruction of the circulation to and from metabolically active muscles. It is proposed that factors related to the level of the perfusion pressure in hyperaemic muscles, possibly located at the venular end of the microcirculation, could account for the changes in V(E) observed.