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Coutier-Marie L.,University of Lorraine | Ioan I.,University of Lorraine | Bonabel C.,Service dExplorations Fonctionnelles Pediatriques | Demoulin B.,University of Lorraine | And 5 more authors.
Frontiers in Physiology | Year: 2017

Introduction: Cough and expiration reflex are major lower airway defense mechanisms that have not been studied throughout development in relation with the feeding behavior. Aim: To describe airway defense reflexes evoked by mechanical stimulation of the trachea in developing rabbit pups. Material and Methods: Sixty one pups were allocated to 3 groups according to their feeding behavior: suckling (n = 22), weanling (n = 21) and weaning (n = 18) group. The incidence and sensitivity of defense reflexes triggered by mechanical tracheal stimulation were studied in anesthetized and tracheotomized animals. Data are expressed as median (25th to 75th percentile). Results: The overall incidence of defensive responses (cough and/or expiration reflex) was found to be significantly higher in suckling [100% (50-100%); p = 0.01] and weanling [75% (40-100%); p = 0.05] animals when compared to weaning ones [37.5% (0-75%)]. However, cough motor pattern accounted for only 29% (0-62%) of all defensive responses in suckling rabbits and its frequency was significantly lower in this group when compared with weanling [100%(50-100%); p = 0.006] or weaning group [62%(50-100%), p = 0.05]. In other word the expiration reflex was the dominant response in suckling animals. Conclusion: Incidence and motor pattern of defensive responses were found to be linked to the pup feeding behavior and the expiration reflex was the major response triggered in suckling pups. The results suggest that this reflex is especially fitted to occur during the coordinated swallowing - breathing fast activities of sucking. © 2017 Coutier-Marie, Ioan, Bonabel, Demoulin, Leblanc, Debitu, Schweitzer, Marchal and Demoulin-Alexikova.


Vu L.T.T.,Saint Paul Hospital Khoa ho Hap Nhi Xanh Pon | Demoulin B.,University of Lorraine | Nguyen M.T.H.,Service dExplorations Fonctionnelles Pediatriques | Nguyen Y.T.,National Pediatric Hospital Benh Vien Tre Em | Marchal F.,University of Lorraine
Pediatric Pulmonology | Year: 2010

There is a high incidence of pediatric asthma in Vietnam, but little lung function data are available. The aim of the study was to compare respiratory resistance (Rrs), reactance (Xrs), and responses to salbutamol between asthmatic and healthy primary school children in Hanoi. Because respiratory mechanics vary along the breathing cycle, measurements were assessed separately in inspiration (Rrsi, Xrsi) and expiration (Rrse, Xrse). Inpatients with doctor-diagnosed asthma were measured 2-3 days following admission using the forced oscillation technique (FOT) at a single frequency (8 Hz). Z-scores and responses to salbutamol were compared between 102 asthmatics and 98 controls, and accuracy of group classification by FOT parameters was assessed by Youden index, an indicator to the proportion of subjects correctly classified in each group. In asthmatics versus controls, Rrsi - but not Rrse - was significantly larger and both Xrsi and Xrse were significantly more negative (P<0.01). Both Rrs and Xrs responses to salbutamol were significantly larger in asthmatics than controls (P<0.001). Youden indexes indicated response to salbutamol generally had better diagnostic values than Z-scores and was best discriminative first with Rrsi, then with Xrse. It is concluded that different FOT characteristics may be described in asthmatic and healthy Vietnamese children. The diagnostic value of each parameter depends upon the breathing cycle. Most useful in practice probably is the response to salbutamol measured by Rrsi. © 2010 Wiley-Liss, Inc.


Marchal F.,Service dExplorations Fonctionnelles Pediatriques | Marchal F.,University of Lorraine
Pediatric Pulmonology | Year: 2015

Summary Assessing lung function in the newborn relates to the need for early markers of chronic respiratory diseases such as cystic fibrosis or asthma. Non-invasive respiratory measurements of forced oscillations mechanics are recently shown to be possible in unsedated babies. The bronchodilator effect of catecholamine release at birth, and the respiratory muscle contribution to respiratory mechanical impedance resulting in sometimes excessive variability suggest that measurements should be performed beyond the first 24 hr of life. Pediatr Pulmonol. 2015; 50:1090-1098. © 2015 Wiley Periodicals, Inc.


Coutier L.,University of Lorraine | Varechova S.,University of Lorraine | Demoulin B.,University of Lorraine | Bonabel C.,Service dExplorations Fonctionnelles Pediatriques | And 5 more authors.
Pediatric Pulmonology | Year: 2014

Background: The measurement of specific airway resistance during tidal breathing (sRawtb) has gained popularity in children, but methodological concerns have been raised regarding the electronic compensation for the thermal artifact. The panting method (sRawp) is efficient in minimizing the latter, but may be associated with a change in end expiratory lung volume if the effort is not properly balanced. The aim of the study was to compare sRawtb with sRawp in children. Methods: Fifty-five children aged 6.5-11.5 years were studied. sRawtb was measured in a commercial plethysmograph. sRawp was measured with a home made equipment that allowed breath by breath analysis (sRawp1) as well as with the commercial body box (sRawp2). Results: sRawtb was significantly larger than either sRawp1 or sRawp2 (P < 0.0001). The mean (95% CI) difference sRawp1 - sRawtb was -0.374 (-0.835 to 0.088) kPa s. The difference between sRawp1 and sRawp2 was significant (P < 0.005) but not clinically relevant, and mean (95% CI) difference sRawp1 - sRawp2 was 0.115 (-0.094 to 0.324) kPa s. The breath by breath analysis showed small but significant increase in sRawp1 throughout the maneuver (P < 0.001), whatever the pattern of end expiratory level. Conclusion: Tidal breathing is associated with an overestimation of sRaw compared with panting in children. Although the latter results in small increase throughout the panting maneuver, sRawp is probably more trustful than sRawtb. © 2013 Wiley Periodicals, Inc.


Varechova S.,Service dexplorations fonctionnelles pediatriques | Varechova S.,University of Lorraine | Demoulin B.,University of Lorraine | Leblanc A.L.,Service dexplorations fonctionnelles pediatriques | And 8 more authors.
Respiratory Physiology and Neurobiology | Year: 2015

A link between cough in childhood and neonatal exposure to hyperoxia following preterm birth has been suggested. The hypothesis is tested that neonatal exposure to hyperoxia is associated with long term up regulation of cough. Airway hyperresponsiveness is also investigated because it is a frequent finding in children born preterm and may be linked to cough.Thirty nine young rabbits survived a 48. h neonatal exposure to 93% oxygen (H, n=. 26) or continued room air (A, n=. 13). Cough response to mechanical tracheal stimulation and airway responses to a mock exercise and to methacholine were studied under anaesthesia.Larger incidence of coughs and increased sensitivity to tracheal stimulation occurred in H vs A (. p<. 0.01), while bronchial responses to exercise or methacholine were similar in both groups.Neonatal hyperoxia is associated with up regulation of cough in young rabbits. The lack of a parallel increase in airway responsiveness suggests up regulation may be of central origin. © 2015 Elsevier B.V.


Coutier L.,Service dExplorations Fonctionnelles Pediatriques | Ioan I.,Service dExplorations Fonctionnelles Pediatriques | Sadegh-Eghbali A.,Service dExplorations Fonctionnelles Pediatriques | Bonabel C.,Service dExplorations Fonctionnelles Pediatriques | And 8 more authors.
Pediatric Pulmonology | Year: 2015

Panting majors turbulent flow and contribution of larger airways to the measurement of specific airway resistance (sRaw). The hypothesis was tested that the difference between asthmatic and healthy children is enhanced by narrowing the flow interval to compute sRaw. sRaw was measured during panting in 40 asthmatic and 25 healthy children and computed using all data points (full scale flow) and limited to the flow intervals ± 1L/sec and ± 0.5 L/sec. sRaw was not different between asthmatics (0.87 ± 0.20 kPa.s) and controls (0.80 ± 0.25 kPa.s) when computed full scale, while it was significantly larger in asthmatics than controls within ± 1L/sec (0.77 ± 0.16 kPa.s vs 0.65 ± 0.15 kPa.s, P < 0.004) or ± 0.5 L/sec (0.77 ± 0.21 kPa.s vs 0.61 ± 0.17 kPa.s, P < 0.002). On the other hand, the within subject coefficient of variation was significantly larger when sRaw was computed within ± 1L/sec (13.7 ± 7.2%) or ± 0.5 L/sec (28.3 ± 18.1%) than full scale (11.0 ± 6.7%), respectively P < 0.002 and P < 0.0001. It is concluded that narrowing the flow interval to compute sRaw is associated with better discrimination between asthma and health in children, although the short term variability of sRaw is increased. Pediatr Pulmonol. 2015; 50:1107-1112. © 2014 Wiley Periodicals, Inc.


Schweitzer C.,Service dExplorations Fonctionnelles Pediatriques | Schweitzer C.,University of Lorraine | Abdelkrim I.B.,Service dExplorations Fonctionnelles Pediatriques | Ferry H.,Service dExplorations Fonctionnelles Pediatriques | And 4 more authors.
Pediatric Research | Year: 2010

Forced expiratory volume in 1 s (FEV1) detection of exercise-induced bronchoconstriction (EIB) to identify asthma has good specificity but rather low sensitivity. The aim was to test whether sensitivity may be improved by measuring respiratory resistance (Rrs) by the forced oscillation technique (FOT). Forty-seven asthmatic and 50 control children (5-12 y) were studied before and after running 6 min on a treadmill. Rrs in inspiration (Rrsi) and expiration (Rrse), FEV1 and Rrsi response to a deep inhalation (DI) were measured before and after exercise. In asthmatics versus controls, exercise induced significantly larger increases in Rrsi (p < 0.001) and larger decreases in FEV1 (p = 0.004). Asthmatics but not controls showed more bronchodilation by DI after exercise (p = 0.02). At specificity >0.90, sensitivity was 0.53 with 25% increase Rrsi and 0.45 with 27% increase Rrse or 5% decrease FEV1. It is concluded that the FOT improves sensitivity of exercise challenge, and the Rrsi response to DI may prove useful in identifying the mechanism of airway obstruction. © 2010 International Pediatric Research Foundation, Inc.


PubMed | University of Lorraine and Service dExplorations Fonctionnelles Pediatriques
Type: Journal Article | Journal: Pediatric pulmonology | Year: 2015

Panting majors turbulent flow and contribution of larger airways to the measurement of specific airway resistance (sRaw). The hypothesis was tested that the difference between asthmatic and healthy children is enhanced by narrowing the flow interval to compute sRaw. sRaw was measured during panting in 40 asthmatic and 25 healthy children and computed using all data points (full scale flow) and limited to the flow intervals 1L/sec and 0.5 L/sec. sRaw was not different between asthmatics (0.87 0.20 kPa.s) and controls (0.80 0.25 kPa.s) when computed full scale, while it was significantly larger in asthmatics than controls within 1L/sec (0.77 0.16 kPa.s vs 0.65 0.15 kPa.s, P < 0.004) or 0.5 L/sec (0.77 0.21 kPa.s vs 0.61 0.17 kPa.s, P < 0.002). On the other hand, the within subject coefficient of variation was significantly larger when sRaw was computed within 1L/sec (13.7 7.2%) or 0.5 L/sec (28.3 18.1%) than full scale (11.0 6.7%), respectively P < 0.002 and P < 0.0001. It is concluded that narrowing the flow interval to compute sRaw is associated with better discrimination between asthma and health in children, although the short term variability of sRaw is increased.


PubMed | Service dExplorations Fonctionnelles Pediatriques
Type: Journal Article | Journal: Pediatric research | Year: 2011

Forced expiratory volume in 1 s (FEV1) detection of exercise-induced bronchoconstriction (EIB) to identify asthma has good specificity but rather low sensitivity. The aim was to test whether sensitivity may be improved by measuring respiratory resistance (Rrs) by the forced oscillation technique (FOT). Forty-seven asthmatic and 50 control children (5-12 y) were studied before and after running 6 min on a treadmill. Rrs in inspiration (Rrsi) and expiration (Rrse), FEV1 and Rrsi response to a deep inhalation (DI) were measured before and after exercise. In asthmatics versus controls, exercise induced significantly larger increases in Rrsi (p < 0.001) and larger decreases in FEV1 (p = 0.004). Asthmatics but not controls showed more bronchodilation by DI after exercise (p = 0.02). At specificity >0.90, sensitivity was 0.53 with 25% increase Rrsi and 0.45 with 27% increase Rrse or 5% decrease FEV1. It is concluded that the FOT improves sensitivity of exercise challenge, and the Rrsi response to DI may prove useful in identifying the mechanism of airway obstruction.


PubMed | Service dExplorations Fonctionnelles Pediatriques
Type: Comment | Journal: Pediatric pulmonology | Year: 2016

Assessing lung function in the newborn relates to the need for early markers of chronic respiratory diseases such as cystic fibrosis or asthma. Non-invasive respiratory measurements of forced oscillations mechanics are recently shown to be possible in unsedated babies. The bronchodilator effect of catecholamine release at birth, and the respiratory muscle contribution to respiratory mechanical impedance resulting in sometimes excessive variability suggest that measurements should be performed beyond the first 24 hr of life.

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