Objective: To assess the effects of wearing a protective mouthguard during exercise on ventilation and oxygen consumption. Design and Setting: All participants performed a graded maximal exercise test on a cycle ergometer to determine peak oxygen consumption (VO2peak). Each participant also performed 6 submaximal exercise tests while wearing one of two facemasks (nasal or non-nasal breathing) and one of three mouthguard conditions (no mouthguard, boil and bite, custom-fit). Steady-state VO2, rate of perceived exertion (RPE), and other ventilatory values were measured at 60% and 80% of VO2max during each submaximal exercise test. All 6 submaximal exercise tests were completed within a 2-week period using a randomized 6x6 balanced Latin square design. Subjects: Twenty-four subjects (age = 20.41 ± 1.99) who were members of the Brigham Young University lacrosse team participated in this study. Measurements: Data were analyzed using a random coefficients growth curve. The full models for all variables included fixed effects for mask, work level, mouthguard, time, and all interactions of the above. Full models were also assumed to have random subject coefficients for the intercepts and slopes relative to time. Results: For VO2 there was a significant effect for facemask type (p<.0001, F = 24.30, df = 1680), mouthguard (p = .0177, F = 4.04, df = 1680), and work (p<.0001, F = 5428.16, df = 1680). For VO2 there was also a significant interaction for mask*work (p = .0280, F = 4.84, df = 1680). For RPE there was a significant effect for facemask type (p = .0005, F = 12.28, df = 1657) and for work (p<.0001, F = 4040.53, df = 1657). For RPE there were also significant interactions for mask*mouthguard (p<.0001, F = 11.82, df = 1657) and for mask*work (p<.0001, F = 18.88, df = 1657). For VE there were significant interactions for mask (p< 0.0001, F = 16.49, df = 1680), mouthguard (p < 0.0001, F = 19.98, df = 1680), and work (p < 0.0001, F = 9122.33, df = 1680). For VE there were also significant interactions for mask*mouthguard (p < 0.002, F = 6.25, df = 1680), and mask*work (p < 0.0001, F = 17.77, df = 1680). Conclusions: Although statistical significance was found for a number of effects, we speculate that the very small differences in the physiological responses to wearing a mouthguard are of little practical significance and would not effect performance. Wearing a mouthguard during exercise does not alter physiological responses and complaints of reduced ventilation are probably psychological.

No description available.

Mokytis kvėpuoti nereikia – kiekvienas žmogus geba tai nuo pat pirmojo savo riksmo gimus (Mejeris, 1997, p. 30). Tačiau kaip kvėpuoti taisyklingai, reikia pasimokyti daugeliui. Daugelis žmonių, deja, kvėpuoja neteisingai, ir dėl to jie turi aibę ligų. Andziulis, Kriščiūnas, Volčeskas ir Rimdeikienė (1999) savo leidinyje kvėpavimo pratimus išskiria, kaip itin veiksmingą būdą, gydant kvėpavimo takų ir plaučių ligas. Bakalauro darbe, analizuojamas specifinės kvėpavimo pratimų programos poveikis vaikams, sergantiems kvėpavimo takų ligomis. Tyrimo tikslas: atskleisti specifinių kvėpavimo pratimų programos poveikį 5 – 6 metų vaikams, sergantiems kvėpavimo takų susirgimais. Tyrimui atskleisti buvo iškelti šie tikslai: atskleisti kvėpavimo pratimų svarbą vaikams, sergantiems kvėpavimo takų susirgimais, remiantis mokslinės literatūros analize; sudaryti specifinę kvėpavimo pratimų programą, skirtą vaikams, sergantiems kvėpavimo takų susirgimais; ištirti ir palyginti eksperimentinės ir kontrolinės grupės vaikų, plaučių, pilvo bei liemens raumenų funkcines galimybes, prieš ir po specifinių kvėpavimo pratimų programos taikymo, taip nustatant eksperimento poveikį. Tyrime dalyvavo dvidešimt Šiaulių sanatorinio lopšelio – darželio „Pušelė“ 5 – 6 metų vaikai, turintys įvairių kvėpavimo takų susirgimų. Buvo sudarytos dvi vaikų grupės (eksperimentinė ir kontrolinė) identiškos pagal jų skaičių. Eksperimento pagalba buvo siekiama išsiaiškinti specifinių kvėpavimo pratimų poveikį tiriamųjų... [toliau žr. visą tekstą] / There is no need to learn to breathe – every human being is able to do it starting from one’s birth and the first cry (Mejeris, 1997, p. 30). Though, to breathe properly one should put some effort in order to learn it. A lot of people breathe in a wrong way and because of this suffer from various diseases. Andziulis, Kriščiūnas, Volčeskas and Rimdeikienė (1999) in their publishing emphasize breathing exercises as a very effective means in treating breathing disorders and lungs diseases. In the study the impact of special breathing exercises on children with various breathing disorders is being analyzed. The aim of the survey is to evaluate the impact of a special program on five – six – year – old children with breathing illnesses. For carrying out the survey the following objectives were pursued: • To emphasize the significance of breathing exercises for children with breathing disorders referring to scientific literature • To create a special program of breathing exercises for sick children • To investigate and compare the results of two groups (experimental and control) in children’s lungs, stomach and waist muscle functional possibilities before and after applying the special program, to evaluate the influence of the experiment on the patients. Twenty five – six – year – old children with breathing disorders from Šiaulių sanatorium – kindergarten “Pušelė” took part in the research. There were two groups (identical according to the number) organised – experimental and... [to full text]

The aim of this research was to investigate the breathing patterns of children aged 5-9 years with asthma as they read aloud stories of increasingly difficulty. Participants were 11 children diagnosed with moderate to severe asthma recruited from an out-patient clinic and 11 gender- and age-matched controls recruited from local schools. Non-contact respiratory monitoring methods were employed to yield acoustic recordings during three non-reading tasks and three reading aloud tasks which increased in difficulty. Measurements included breathing rate, pause time in speech, and time ratio between inspiration between inspiration and expiration (I/E ratio). Pauses that occurred during the reading tasks were classified as either occurring at grammatical junctions where pausing during oral reading would be expected, or at ungrammatical junctions, where pausing was associated with either needing to breath, a reading mistake and/or upon recognition of an unknown word. The acoustic measures were recorded using a free audio editor and recorder programme (Audacity version 2.0.3’) on a Notebook laptop with an inbuilt microphone. The main result indicated that 82% of children with asthma breathed more slowly when reading books that were difficult for them, and this was negatively associated with asthma severity (p=0.046). The findings demonstrated that children with asthma appear to cope when reading more difficult materials by breathing more slowly, pausing for longer ([F(1, 16) = 5.454, p = 0.033]) and increasing expiration time. The current research is the first of its kind and provides a base for future studies to investigate the relationship between breathing and the reading of children with asthma. Questions remain whether this relationship is related to low achievement in reading. Future research to confirm, disconfirm or otherwise is necessary to add to the sparse literature on the breathing of children with asthma while reading aloud.

No description available.

Published Article / The aim of the study was to determine the influence of controlled breathing on school principals' stress relief. The research sample consisted of six primary school principals purposefully selected on the basis of years of school principal experience and the voluntary attendance of a stress alleviation workshop. Based on an interpretive paradigm employing a mixed-methods research approach, a structured questionnaire was used to compare participants' levels of stress before and after attendance of a stress alleviation workshop that focused on controlled breathing. By means of in-depth individual interviews the manifestation of the influence of controlled breathing on participants' stress relief was investigated. Data from the structured questionnaires were analysed as frequencies and mean scores. Through qualitative content analysis data from the individual interviews were analysed as emerging categories and themes. It was found that the regular practising of controlled breathing resulted in participants' stress relief with main improvements related to revitalised energy levels, restored clarity of thinking and improved interpersonal relationships. The findings contribute to research on constructive ways of stress relief within the school environment.

BACKGROUND:We tested the hypothesis that ventilatory drive in hypoxia and hypercapnia is inversely correlated with the number of hypopneas and obstructive apneas per hour of sleep (obstructive apnea hypopnea index, OAHI) in children.METHODS:Fifty children, 6 to 12 years of age were studied. Participants had an in-home unattended polysomnogram to compute the OAHI. We subsequently estimated ventilatory drive in normoxia, at two levels of isocapnic hypoxia, and at three levels of hyperoxic hypercapnia in each subject. Experiments were done during wakefulness, and the mouth occlusion pressure measured 0.1 seconds after inspiratory onset (P0.1) was measured in all conditions. The slope of the relation between P0.1 and the partial pressure of end-tidal O2 or CO2 (PETO2 and PETCO2) served as the index of hypoxic or hypercapnic ventilatory drive.RESULTS:Hypoxic ventilatory drive correlated inversely with OAHI (r = -0.31, P = 0.041), but the hypercapnic ventilatory drive did not (r = -0.19, P = 0.27). We also found that the resting PETCO2 was significantly and positively correlated with the OAHI, suggesting that high OAHI values were associated with resting CO2 retention.CONCLUSIONS:In awake children the OAHI correlates inversely with the hypoxic ventilatory drive and positively with the resting PETCO2. Whether or not diminished hypoxic drive or resting CO2 retention while awake can explain the severity of sleep-disordered breathing in this population is uncertain, but a reduced hypoxic ventilatory drive and resting CO2 retention are associated with sleep-disordered breathing in 6-12 year old children.

The autonomic nervous system (ANS) controls most involuntary functions of the body. Dysfunctions of the ANS can be life-threatening. However, several critical questions related to cardiovascular and breathing regulations remain unclear. One of the open questions is how the system lose control of the vascular tones under certain circumstances. Using the septic shock model induced by lipopolysaccharide (LPS) in isolated and perfused mesenteric arterial rings, we found the vascular hyporeactivity is attributed to the decreased vasoconstriction to α-adrenoceptor agonists. The endotoxin-induced vasodilation can be intervened with endothelin-1 (ET-1), serotonin (5-HT) or vasopressin, which have never been used in clinical treatment. It is unclear how the excitability of endothelium affects vascular tones. Using optogenetics and transgenic mice with channelrhodopsin expression in endothelial cells (ECs), we found selective activation of the ECs induces a fast, robust, reproducible and long-lasting vasoconstriction in isolated and perfused hearts and kidneys. Breathing control by the ANS within the brain becomes abnormal in certain genetic diseases, such as Rett syndrome with defected norepinephrine (NE) system in locus coeruleus (LC). The LC neurons are hyperexcitable while NE release is deficient. Using optogenetics and double transgenic mice with Mecp2 null and channelrhodopsin expression in LC neurons, we found the NE-ergic modulation of hypoglossal neurons was impaired in transgenic mice, which cannot be improved with optostimulation, suggesting that LC neuronal hyperexcitability may not benefit the NE modulation in Rett syndrome. Collectively, our results provide insight into the autonomic dysfunctions using experimental interventions that have barely been used before.

Nasal high flow (NHF) cannulae are used to deliver heated and humidified air to patients at steady flows ranging from 5-50 l/min. Knowledge of the airflow characteristics within the nasal cavity with NHF and during natural breathing is essential to understand the treatment's efficacy. In this thesis, the distribution and velocity of the airflow in the human nasal cavity have been mapped during natural and NHF assisted breathing with planar- and stereo-PIV in both steady and oscillatory flow conditions. Anatomically accurate transparent silicone models of the human nasal cavity were constructed using CT scan data and rapid prototyping. Breathing flowrates and waveforms were measured in vivo and dimensionally scaled by Reynolds and Womersley number matching to reproduce physiological conditions in vitro. Velocities of 2.8 and 3.8 m/s occurred in the nasal valve during natural breathing at peak expiration and inspiration, respectively; however on expiration the maximum velocity of 4.2 m/s occurred in the nasopharynx. Velocity magnitudes differed appreciably between the left and right sides of the nasal cavity, which were asymmetric. NHF modifies nasal cavity flow patterns significantly, altering the proportion of inspiration and expiration through each passageway and producing jets with in vivo velocities up to 20.8 m/s for 40 l/min cannula flow. The main flow stream passed through the middle airway and along the septal wall during both natural inspiration and expiration, whereas NHF inspired and expired flows remained high through the nasal cavity. Strong recirculating features are created above and below the cannula jet. Results are presented that suggest the quasi-steady flow assumption is invalid in the nasal cavity during both natural and NHF assisted breathing. The importance of using a three-component measurement technique when investigating nasal flows has been highlighted. Cannula flow has been found to continuously flush the nasopharyngeal dead space, which may enhance carbon dioxide removal and increase oxygen fraction. Close agreement was found between numerical and experimental results performed in identical conditions and geometries.

No description available.