[The new reference equations of the Global Lung function Initiative (GLI) for pulmonary function tests]. / Les nouvelles équations de référence du Global Lung Function Initiative (GLI) pour les explorations fonctionnelles respiratoires.

Until recently, the reference equations available for pulmonary function tests (PFTs) have had several weaknesses: they have often been based on relatively weak samples of normal subjects; they used mathematical models that are not very efficient in describing the evolution of PFTs over age; there were different equations for children/adolescents and for adults; the expression of the results solely as a percentage of the predicted value did not provide a good indication of the statistical significance of any difference that may exist between a measured value and its reference value. The Global Lung Initiative (GLI) aimed to establish new reference equations for PFTs that do not have these disadvantages. Based on large, representative, reference populations and allowing individualization of homogeneous ethnic groups over a wide age range, the GLI uses a statistical model that does not have any a priori hypothesis regarding the evolution of PFTs as a function of age (these models therefore make it possible to describe, in a very precise manner, the PFTs over all age ranges). For a given PFT, the equation is the same regardless of age (no discontinuity on transition to adulthood). The GLI equations are used to define a reference value, a threshold value (lower limit of the normal) and a z-score that take into account age, sex, size and, for some PFTs, ethnicity. The reference equations of the GLI were established in 2012 for spirometry, in 2017 for the TLCO and will soon be established for lung volumes. Already the representation of ethnic groups not identified by the GLI and of subjects with extreme values of age and size is being questioned.

Intermittent versus constant aerobic exercise in middle-aged males: acute effects on arterial stiffness and factors influencing the changes.

PURPOSE: Both constant and intermittent acute aerobic exercises have been found to decrease arterial stiffness. However, direct comparisons of these two types of exercise are sparse. It is not known which type of exercise has the greatest effect. METHODS: We evaluated the haemodynamic responses in 15 males (age 48.5 ± 1.3 years; BMI 27.5 ± 0.8 kg m-2) following acute constant (CE) and intermittent cycling exercise (IE). Duration and heart rate were matched during both exercises (131.8 ± 3.2 bpm for CE and 132.0 ± 3.1 bpm for IE). Central and peripheral arterial stiffness was assessed through pulse wave velocity (PWV). Plasma concentrations of nitric oxide (NO), atrial natriuretic peptide (ANP), blood lactate, noradrenaline, and adrenaline were measured before and after each exercise. RESULTS: Central (+ 1.8 ± 7.4 and - 6.5 ± 6.8% for CE and IE) and upper limb PWV (+ 2.7 ± 6.2 and - 8 ± 4.6% for CE and IE) were not significantly altered although a small decrease (small effect size) was observed after IE. However, lower limb PWV significantly decreased after exercises (- 7.3 ± 5.7 and - 15.9 ± 4% after CE and IE), with a larger effect after IE. CONCLUSIONS: Greater decrease in lower limb PWV occurred after IE despite greater heart rate. This may be due to the higher blood levels of lactate during IE, while NO, ANP, noradrenaline, and adrenaline levels remained not statistically different from CE. These results underlined the importance of lactate in triggering the post-exercise vascular response to exercise, as well as its regional characteristic.

Alterations in Body Fluid Balance During Fin Swimming in 29 °C Water in a Population of Special Forces Divers.

Highly trained "combat swimmers" encounter physiological difficulties when performing missions in warm water. The aim of this study was to assess the respective roles of immersion and physical activity in perturbing fluid balance of military divers on duty in warm water. 12 trained divers performed 2 dives each (2 h, 3 m depth) in fresh water at 29 °C. Divers either remained Static or swam continuously (Fin) during the dive. In the Fin condition, oxygen consumption and heart rate were 2-fold greater than during the Static dive. Core and skin temperatures were also higher (Fin: 38.5±0.4 °C and 36.2±0.3 °C and Static: 37.2±0.3 °C and 34.3±0.3 °C; respectively p=0.0002 and p=0.0003). During the Fin dive, the average mass loss was 989 g (39% urine loss, 41% sweating and 20% insensible water loss and blood sampling); Static divers lost 720 g (84% urine loss, 2% sweating and 14% insensible water loss and blood sampling) (p=0.003). In the Fin condition, a greater decrease in total body mass and greater sweating occurred, without effects on circulating renin and aldosterone concentrations; diuresis was reduced, and plasma volume decreased more than in the Static condition.

Typology of "Fatigue" by Heart Rate Variability Analysis in Elite Nordic-skiers.

This study investigated changes in heart rate variability (HRV) in elite Nordic-skiers to characterize different types of "fatigue" in 27 men and 30 women surveyed from 2004 to 2008. R-R intervals were recorded at rest during 8 min supine (SU) followed by 7 min standing (ST). HRV parameters analysed were powers of low (LF), high (HF) frequencies, (LF+HF) (ms(2)) and heart rate (HR, bpm). In the 1 063 HRV tests performed, 172 corresponded to a "fatigue" state and the first were considered for analysis. 4 types of "fatigue" (F) were identified: 1. F(HF(-)LF(-))SU_ST for 42 tests: decrease in LFSU (- 46%), HFSU (- 70%), LFST (- 43%), HFST (- 53%) and increase in HRSU (+ 15%), HRST (+ 14%). 2. F(LF(+) SULF(-) ST) for 8 tests: increase in LFSU (+ 190%) decrease in LFST (- 84%) and increase in HRST (+ 21%). 3. F(HF(-) SUHF(+) ST) for 6 tests: decrease in HFSU (- 72%) and increase in HFST (+ 501%). 4. F(HF(+) SU) for only 1 test with an increase in HFSU (+ 2161%) and decrease in HRSU (- 15%). Supine and standing HRV patterns were independently modified by "fatigue". 4 "fatigue"-shifted HRV patterns were statistically sorted according to differently paired changes in the 2 postures. This characterization might be useful for further understanding autonomic rearrangements in different "fatigue" conditions.

Effects of three postexercice recovery treatments on femoral artery blood flow kinetics.

AIM: This study aimed to compare the kinetics of muscle leg blood flow during three recovery treatments following a prolonged exercise: contrast water therapy (CWT), compression stockings (CS) or passive recovery (PR). METHODS: Fifteen men came to the laboratory three times to perform a 45-min exercise followed 5 min after by a standardized 12-min recovery treatment in upright position, alternating between two vats every 2 min: CWT (cold: ~12 °C to warm: 36 °C), CS (~20 mmHg) or PR. The order of treatments was randomized. Blood flow was measured using Doppler ultrasound during the recovery treatments (i.e., min 3, 5, 7 and 9) in the superficial femoral artery distally to the common bifurcation (~3 cm) (above the water and stocking). RESULTS: Blood flow was significantly higher during CWT (P<0.01; +22.91%) and CS (P<0.05; +15.26%) than during PR. Although no statistical difference between CWT and CS was observed, effect sizes were larger during CWT (large) than during CS (moderate). No changes in blood flow occurred in the femoral artery between hot and cold transitions of CWT. CONCLUSION: During immediate recovery of a high intensity exercise, CWT and CS trigger higher femoral artery blood flow than PR. Moreover, effect sizes were greater during CWT than during CS.

Changes in femoral artery blood flow during thermoneutral, cold, and contrast-water therapy.

AIM: The purpose of this study was to examine the changes in femoral artery blood flow during cold water immersion (CWI), contrast water therapy (CWT) and thermoneutral water immersion (TWI). METHODS: Ten athletes came to the laboratory three times, to complete a 20-min procedure in upright position: 4 min in air (baseline), then 16-min full leg TWI (~35 °C), CWI (~12 °C) or CWT (2:2 ~12 °C to ~35 °C) min ratio, in a random order. Blood flow was measured every 2 min: baseline (i.e. min 3 and 1) and throughout water immersion (i.e. min 1, 3, 5, 7, 9, 11, 13 and 15), using Doppler ultrasound in the superficial femoral artery, distal to the common bifurcation (~3 cm), above the water and stocking. RESULTS: Compared with baseline, blood flow was significantly higher throughout TWI (min 1 to 15: P<0.001; +74.6%), significantly lower during CWI (from min 7 to 15: P<0.05; -16.2%) and did not change during CWT (min 1 to 15). No changes in blood flow occurred between the hot and cold transitions of CWT. CONCLUSION: This study shows that external hydrostatic pressure (TWI ~35 °C) significantly increases femoral artery blood flow. We also show that associating hydrostatic pressure with cooling (CWI ~12 °C) decreases femoral artery blood flow after a sufficient duration, whereas associating hydrostatic pressure with alternating brief exposures to contrasted temperatures does not change femoral artery blood flow under resting conditions.

Mediastinal recurrence from ovarian cystadenocarcinoma presenting as pleuro-pericardial cyst.

A 56 year-old woman (treated for ovarian cystadenocarcinoma 9-yrs before) presented a slowly increasing dyspnea. CT-scan revealed a mediastinal cyst with typical radiological pattern compatible with benign pleuro-pericardial cyst. The cyst was removed via right thoracoscopy. Surprisingly, the pathology were indicative of cystic mediastinal recurrence from ovarian adenocarcinoma.

Systematic lymph node dissection in lung metastasectomy of renal cell carcinoma: an 18 years of experience.

BACKGROUND: Pulmonary metastasectomy of renal cell carcinomas (RCC) remains controversial. Thoracic lymph node involvement (LNI) is a known prognostic factor. The aim of our analysis is to evaluate whether patients with LNI, and particularly N2 patients, should be excluded from surgical treatment. METHODS: We retrospectively reviewed data from 122 patients who underwent operations at two French thoracic surgery departments between 1993 and 2011 for RCC lung metastases. RESULTS: The population consisted of 38 women and 84 men; the average age at time of metastasectomy was 63.3 years (min: 43, max: 82). LNI was identified as a prognostic factor using univariate and multivariate analysis (median survival: 107 months vs. 37 months, P = 0.003; HR = 0.384 (0.179; 0.825), P = 0.01, respectively). Although differences in survival between metastases at the hilar and mediastinal locations were not significant (median survival: 74 months vs. 32 months, respectively, P = 0.75), length of survival time was associated with disease-free interval less than 12 months (median survival: 23 months vs. 94 months, P < 0.0001; HR = 3.081 (1.193; 7.957), P = 0.02). CONCLUSION: Although LNI has an adverse effect on survival; long-term survival can be achieved in pN+ patients. Consequently, these patients should not be excluded from surgery. Systematic lymphadenectomy should be performed to obtain more accurate staging and to determine appropriate adjuvant treatment.

The underestimated compression effect of neoprene wetsuit on divers hydromineral homeostasis.

This study aimed at demonstrating that the neoprene wetsuit provides not only thermal protection. Compression it exerts on the diver's shell significantly impacts hydromineral homeostasis by restraining the systemic vascular capacity and secondarily increasing urine output on dry land and during scuba diving. 8 healthy divers underwent five 2-h sessions: sitting out of water in trunks (control situation), sitting out of water wearing a wetsuit, and 3 wetsuit scuba-immersed sessions at 1, 6 and 12 msw depth, respectively. Urine volumes and blood samples were collected. Hemoglobin (Hb), hematocrit (Ht) and plasma sodium concentration were measured. Interface pressure between the garment and the skin was measured at 17 sites of the body shell, with a pressure transducer. Mean interface pressures between wetsuit and skin amounted to: 25.8±2.8 mm Hg. Whatever the depth, elastic recoil tension of wetsuit material was unchanged by immersion. Weight loss was respectively 2 and 3 times greater when wetsuit was worn out of water (430 g) and during immersion (710 g) than when divers did not wear any wetsuit out of water (235 g; p<0.05). Urine volume accounted for 85% of weight loss in either session. Weight loss and urine volume were similar whatever immersion depth. The decrease in plasma volume amounted to 8% of urine volume when divers did not wear any wetsuit out of water, and to 30% when wetsuit was worn out of water or during immersion. Diving wetsuit develops a pressure effect that alters diver's hydromineral homeostasis. During immersion, the wetsuit pressure merges into the larger main effect of hydrostatic pressure to reduce water content of body fluids, unrelated to immersion depth.

[COPD in dairy farmers: screening, characterization and constitution of a cohort. The BALISTIC study]. / BPCO des producteurs laitiers : dépistage, caractérisation et constitution d'une cohorte. Étude BALISTIC.

BACKGROUND: A pilot study from our group suggests that the prevalence of chronic obstructive pulmonary disease (COPD) among dairy farmers is higher than in the general population although dairy workers are less frequently smokers. OBJECTIVES AND METHODS: The study presented here aims at (i) determining the prevalence of COPD in a large and representative population of dairy farmers; (ii) characterizing these patients in terms of smoking habits, dyspnoea, quality of life, lung function, bronchial exhaled nitric oxide, systemic inflammation, arterial stiffness and exercise capacity; (iii) comparing characteristics of dairy farmers' COPD with the characteristics of COPD in patients without any occupational exposure; (iv) identifying the etiological factors of COPD in dairy farmers; and (v) constituting a cohort of COPD patients and control subjects for further longitudinal studies. Two groups of COPD patients (dairy farmers or not) and two groups of controls subjects will be selected among a representative panel of 2000 dairy workers and 2000 subjects without any occupational exposure, all aged 40 to 75 years. EXPECTED RESULTS: A better knowledge of the epidemiology and pathophysiology of COPD in dairy farmers should guide a specific strategy of prevention. The knowledge of the characteristics of COPD occurring in dairy farmers will help to define the therapeutic modalities that might be different compared with the therapeutic recommendations for COPD secondary to tobacco smoking.

FADD protein release mirrors the development and aggressiveness of human non-small cell lung cancer.

BACKGROUND: The need to unfold the underlying mechanisms of lung cancer aggressiveness, the deadliest cancer in the world, is of prime importance. Because Fas-associated death domain protein (FADD) is the key adaptor molecule transmitting the apoptotic signal delivered by death receptors, we studied the presence and correlation of intra- and extracellular FADD protein with development and aggressiveness of non-small cell lung cancer (NSCLC). METHODS: Fifty NSCLC patients were enrolled in this prospective study. Intracellular FADD was detected in patients' tissue by immunohistochemistry. Tumours and distant non-tumoural lung biopsies were cultured through trans-well membrane in order to analyse extracellular FADD. Correlation between different clinical/histological parameters with level/localisation of FADD protein has been investigated. RESULTS: Fas-associated death domain protein could be specifically downregulated in tumoural cells and FADD loss correlated with the presence of extracellular FADD. Indeed, human NSCLC released FADD protein, and tumoural samples released significantly more FADD than non-tumoural (NT) tissue (P=0.000003). The release of FADD by both tumoural and NT tissue increased significantly with the cancer stage, and was correlated with both early and late steps of the metastasis process. CONCLUSION: The release of FADD by human NSCLC could be a new marker of poor prognosis as it correlates positively with both tumour progression and aggressiveness.

Heart rate variability to assess ventilatory thresholds: reliable in cardiac disease?

BACKGROUND: The first (VT1) and second (VT2) ventilatory thresholds are landmarks to tailor exercise rehabilitation in coronary artery disease (CAD) or chronic heart failure (CHF). Methods allowing VT1 and VT2 determination based on heart rate variability (HRV) have been proposed but not yet evaluated in these patients. DESIGN: To determine the heart rate (HR) associated with VT1 and VT2 by three methods of HRV analyses. METHODS: Fourteen CHF and 24 CAD patients performed an exercise test on a cycle ergometer (10 -W every minute until exhaustion). VT1 and VT2 were determined with the 'respiratory equivalent' method. HR at VT1 was determined with the standard deviation (SD) of R⊟R intervals (VT(SD)) and of the instantaneous beat-to-beat variability of the Poincaré plot method (VT(Poincaré)). HR at VT1 and VT2 was determined through a time-varying HRV analysis method (VT(TV1) and VT(TV2), respectively). RESULTS: HR at VT(SD) was significantly higher than HR at VT1. No significant differences were observed between HR at VT(Poincaré), VT(TV1), and at VT1, nor between HR at VT(TV2) and VT2. HR at VT(SD), VT(Poincaré), and VT1 were significantly correlated, but with a low r (2) value and a large mean HR difference. With the time-varying method, the mean HR difference was lower than 5% and the correlation coefficients were higher (especially for VT(TV2)). CONCLUSIONS: SD and Poincaré plot methods lead to substantial inaccuracy in HR estimates. The time-varying HRV analysis led to strong correlation coefficients and low limits of agreement. Therefore, this method may be a promising, low-cost tool for non-invasive assessment of the ventilatory thresholds in cardiac disease.

Compression sleeves increase tissue oxygen saturation but not running performance.

The purpose of this study was to determine the effects of calf compression sleeves on running performance and on calf tissue oxygen saturation (StO2) at rest before exercise and during recovery period. 14 moderately trained athletes completed 2 identical sessions of treadmill running with and without calf compression sleeves in randomized order. Each session comprised: 15 min at rest, 30 min at 60% maximal aerobic velocity determined beforehand, 15 min of passive recovery, a running time to exhaustion at 100% maximal aerobic velocity, and 30 min of passive recovery. Calf StO2 was determined by near infra-red spectroscopy and running performance by the time to exhaustion. Compression sleeves increased significantly StO2 at rest before exercise (+ 6.4±1.9%) and during recovery from exercise (+ 7.4±1.7% and + 10.7±1.8% at 20th and 30th min of the last recovery period, respectively). No difference was observed between the times to exhaustion performed with and without compression sleeves (269.4±18.4 s and 263.3±19.8 s, respectively). Within the framework of this study, the compression sleeves do not improve running performance in tlim. However the StO2 results argue for further interest of this garment during effort recovery.

[Pulmonary blastoma in an adult]. / Le pneumoblastome de l'adulte.

The authors report the case of a 24-year-old woman in complete remission 4 years after treatment for a biphasic pulmonary blastoma. After a left lower lobectomy, the patient developed a local recurrence that was treated by chemotherapy. In the light of this case, the authors review the clinical, radiological and therapeutic features of this very rare malignant lung tumour.

Evaluation of cardiorespiratory functional reserve from arm exercise in the elderly.

BACKGROUND: When the subject is not able to satisfy traditional testing procedures, alternative exercises or indices such as arm cranking or the oxygen uptake efficiency slope (OUES) have been proposed. However, the OUES has not yet been used on elderly subjects from an exercise performed with the arms. OBJECTIVE: The aim of our study was to evaluate the possibility of using the OUES as an index of the cardiorespiratory functional reserve in the elderly when the exercise evaluation test is performed with the arms and when this parameter is estimated from submaximal responses. METHODS: Seventeen adults (62-82 years) undergoing total joint arthroplasty of the hip took part in this study. Maximal incremental exercise tests were performed on an arm crank ergometer 1 month before (T1) and 2 months after (T2) surgery. Gas exchanges were measured continuously to determine oxygen consumption at peak exercise (V˙O2 peak) and were used to calculate the OUES. The correlation coefficient was calculated between V˙O2 peak and OUES, and their relative changes between T1 and T2. RESULTS: V˙O2 peak was not significantly different between T1 and T2: 10.3 ± 0.7 and 9.8 ± 0.5 mL/min per kilogramme respectively. The OUES estimated from submaximal responses did not show a significant difference between T1 and T2. Significant correlations were observed between individual V˙O2 peak and OUES, as well as at T1 and T2. CONCLUSION: The use of arm cranking exercises and the calculation of the OUES from the submaximal respiratory response can be used for the objective quantification of cardiorespiratory functional reserve in the elderly.

Pulmonary oedema in healthy SCUBA divers: new physiopathological pathways.

INTRODUCTION: The mechanism of immersion pulmonary oedema occurring in healthy divers is a matter of debate. Among consecutive injured divers admitted to our hyperbaric centre, we analysed prospective data about pulmonary oedema. METHOD: A total of 22 divers suffering from immersion pulmonary oedema without cardiac disease were included. The occurrence of events was compared to the diving conditions as assessed by diving-computer. Each patient underwent a clinical examination, laboratory tests, thoracic CT scan and echocardiography. RESULTS: The median age was 49 years, with a higher proportion of women, in comparison with the data of the French diving federation. The common feature was the occurrence of respiratory symptoms during the ascent after median dive duration of 29 min with strenuous exercise and/or psychological stress. Most of the dives were deep (37 msw-121 fsw) in cool water (15 degrees C-59 degrees F). The average inspired oxygen partial pressure was 0.99 bar. Progression was rapidly favourable, and the medical check-up after clinical recovery was normal. CONCLUSION: Immersion, body cooling, hyperoxia, increased hydrostatic pressure and strenuous exercise likely combine to induce pulmonary oedema in patients without cardiac disease. This study underlines new physiopathological tracks related to the frequent occurrence of symptoms noticed in the last part of the ascent and a higher incidence in women.

Exercise rehabilitation restores physiological cardiovascular responses to short-term head-out water immersion in patients with chronic heart failure.

PURPOSE: Rehabilitation programs increasingly involve immersed exercising, including inpatients suffering from severe cardiovascular diseases such as coronary artery disease (CAD) or chronic heart failure (CHF). The hemodynamic responses to short-term head-out water immersion are not well defined in these diseases. This study was aimed at evaluating (1) the cardiac and peripheral hemodynamic responses to short-term head-out water immersion in patients with CHF (n = 12) and CAD (n = 12) and (2) the effect of a rehabilitation program on these responses. METHODS: Wrist arterial tonometry was performed in the upright posture before and during immersion (1.30-m depth) once before and once after a 3-week rehabilitation program including gymnic water exercises. RESULTS: In patients with CAD, water immersion triggered a significant increase in stroke volume, cardiac output, and pulse pressure and a significant decrease in pulse rate, diastolic blood pressure, and systemic vascular resistances, both before and after the rehabilitation program. In patients with CHF, no significant immersion-linked changes in cardiovascular variables were observed before rehabilitation. However, after completion of the rehabilitation program, it was found that water immersion caused significant increases in stroke volume, cardiac output, and pulse pressure. CONCLUSION: In patients with CHF, this 3-week rehabilitation program restored the usual central responses to head-out water immersion (increase in stroke volume and cardiac output). In both patients with CHF and CAD, acute water immersion did not change arterial compliance.

Effects of a primary rehabilitation programme on arterial vascular adaptations in an individual with paraplegia.

OBJECTIVE: Evaluation of the effects of 6 weeks of wheelchair endurance training on arterial stiffness in an individual with paraplegia. METHODS: A 22-year-old male patient with complete (ASIA A) paraplegia (T11) was tested before and after training (30 minutes three times per week). Physical performance and cardiorespiratory response were evaluated during a maximal progressive test. Heart rate (HR), blood pressure, stroke volume and arterial carotid-wrist and carotid-ankle pulse wave velocity (PWV) were measured at rest. RESULTS: Maximal responses registered (maximal tolerated power, VO2 peak) during the exercise test were increased after training. At rest, HR as PWV decreased, whereas cardiac output and blood pressure remained constant. CONCLUSION: Continuous exposure of the subject to a repeated high intensity exercise bout for 6 weeks elevated fitness level. Such a regular practice might also constitute a major way to trigger vascular remodelling beyond to the trained body part.

Military diving training improved arterial compliance.

This study was aimed at investigating whether repeated SCUBA diving might induce long term cardiovascular and autonomic modifications. In 11 military mine clearance diving students, arterial compliance (ultrasound scan study of brachial artery and ratio of stroke volume to pulse pressure: SV/PP), resting spectral analyses of heart rate and blood pressure variability, and a cold pressor test were performed before and after a 15-week military diving training course. After the diving training, arterial compliance was improved, as indicated by the significant increase in brachial arterial compliance (from 24+/-10 to 37+/-14 ml.mmHg (-1)) and SV/PP (from 1.7+/-0.2 to 1.9+/-0.2 ml.mmHg (-1)), and by the significant decrease in systolic, diastolic and pulse pressures (from 130+/-8 to 120+/-7; from 71+/-4 to 67+/-4; and from 58+/-8 to 53+/-5 mmHg, respectively). The peak oxygen uptake increased significantly from 54.3+/-2.0 to 56.8+/-4.0 mL.kg (-1).min (-1). Finally, the vasoconstrictive response during the cold pressor test increased (p<0.05). These findings point to a positive effect of a 15-week military diving training course on vascular function, and for a concomitant development of some peripheral vascular acclimatization to cold.