Evaluation of Airway Volume in Cleft Lip and Palate Following Nasoalveolar Molding.

Patients with cleft lip and palate (CLP) have commonly reduced nasal airways and are more prone to snoring, mouth breathing and hypopnea during sleep. Therefore, the morphometric evaluation of pharyngeal airway in patients with CLP is crucial. The purpose of this study is to evaluate the pharyngeal airway volumes of patients with CLP who underwent nasoalveolar molding (NAM) and to compare them with a well-matched control group without NAM. The study consisted of 40 patients with CLP divided into 2 main groups (26 with NAM; 14 without NAM) and 4 subgroups (15 unilateral CLP [UCLP] with NAM, mean age: 10.13 ±â€Š1.30 years; 11 bilateral CLP [BCLP] with NAM, mean age: 10.55 ±â€Š1.51 years; 7 UCLP without NAM, mean age: 9.86 ±â€Š1.68 years; 7 BCLP without NAM, mean age: 10.28 ±â€Š1.89 years). Nasopharyngeal, oropharyngeal, and total airway volumes of all the patients were calculated 3-dimensionally with cone-beam computed tomography. There were statistically significant differences in nasopharyngeal volume (P < 0.05) of NAM group compared to control group; however, volumetric differences in oropharyngeal and total pharyngeal airway were not significant (P > 0.05). The amount of nasopharyngeal, oropharyngeal, and total pharyngeal airway size in the BCLP with NAM group was significantly larger compared to BCLP without NAM group (P < 0.05). However, UCLP did not show any significant difference in NAM group (P > 0.05). This study implies that NAM can effectively enlarge the nasopharyngeal airway size in patient with CLP. In addition, the pharyngeal airway volume enlargement is more apparent in BCLP than UCLP individuals.

Cardiovascular and respiratory effects of the neoprene wetsuit in non-immersed divers.

A neoprene wetsuit is widely used to reduce thermal dispersion during diving. Recent observations have pointed out that elastic recoil of the wetsuit might have significant compressive effects, able to affect water and electrolyte homeostasis during both dry and immersed conditions. The aim of this study was to evaluate the possible cardiovascular and respiratory effects of the neoprene wetsuit in dry conditions in a sample of experienced divers. Twenty-four (24) healthy divers were evaluated by Doppler-echocardiography and by spirometry in basal conditions and while wearing a full neoprene wetsuit. During wetsuit conditions, we observed a significant decrease in heart rate (-5%; p ⟨ 0.05) and cardiac output (-12%; p ⟨ 0.05), and a significant increase in total peripheral resistances (15%; p ⟨ 0.05). Moreover, a significant reduction of right ventricular early diastolic filling was observed (-15%; p ⟨ 0.05). As concerns pulmonary function, a significant reduction of vital capacity (-2%; p ⟨ 0.001) and expiratory reserve volume (-25%; p ⟨ 0.001), and a significant increase of inspiratory capacity (9%; p ⟨ 0.001) and tidal volume (25%; p ⟨ 0.05) were observed. These data support the hypothesis that neoprene elastic recoil, possibly due to a compression exerted on chest, might affect systemic circulation (decreasing cardiac output and impairing right ventricular filling) and respiratory function.

Efficacy and safety of once daily triamcinolone acetonide aqueous nasal spray in adults with non-allergic and allergic rhinitis.

BACKGROUND: The efficacy of corticosteroid has not been thoroughly studied in the treatment of non-allergic rhinitis. This study was designed to compare the efficacy of nasal corticosteroid in patients with allergic rhinitis (AR), and non-allergic rhinitis (NAR). METHODS: The efficacy of triamcinolone acetonide nasal spray (TANS) on total nasal symptom scores (TNSS), and nasal peak inspiratory flow rate (nPIFR) was studied in a six-week parallel-group trial of NAR (n: 25), and AR (n: 16) patients. Health-related quality of life (HRQoL) and Epworth Sleepiness Scale (ESS) were also analysed. RESULTS: The TNSSs, and symptom scores of conjunctivitis, snoring, and postnasal drainage were significantly improved in both groups, after two and six weeks of treatment. In contrast to AR, patients with NAR had statistically significant improvement in nasal obstruction, and postnasal drainage beginning from two weeks of the treatment. nPIFR slightly increased in both groups. Scores of generic (SF-36), rhinitis specific (MiniRQLQ) and ESS questionnaires generally improved better in AR than NAR. TANS was well-tolerated in AR and NAR groups with minor adverse events including headache, nasal burning, and bitter mouth taste. CONCLUSIONS: Our study disproved the idea of ineffectiveness of corticosteroid treatment in NAR, and showed that triamcinolone acetate may be an alternative drug in the treatment of NAR.

Obesity and obstructive sleep apnoea: mechanisms for increased collapsibility of the passive pharyngeal airway.

Epidemiological evidence suggests there are significant links between obesity and obstructive sleep apnoea (OSA), with a particular emphasis on the importance of fat distribution in the development of OSA. In patients with OSA, the structure of the pharyngeal airway collapses. A collapsible tube within a rigid box collapses either due to decreased intraluminal pressure or increased external tissue pressure (i.e. reduction in transmural pressure), or due to reduction in the longitudinal tension of the tube. Accordingly, obesity should structurally increase the collapsibility of the pharyngeal airway due to excessive fat deposition at two distinct locations. In the pharyngeal airway region, excessive soft tissue for a given maxillomandibular enclosure size (upper airway anatomical imbalance) can increase tissue pressure surrounding the pharyngeal airway, thereby narrowing the airway. Even mild obesity may cause anatomical imbalance in individuals with a small maxilla and mandible. Lung volume reduction due to excessive central fat deposition may decrease longitudinal tracheal traction forces and pharyngeal wall tension, changing the 'tube law' in the pharyngeal airway (lung volume dependence of the upper airway). The lung volume dependence of pharyngeal airway patency appears to contribute more significantly to the development of OSA in morbidly obese, apnoeic patients. Neurostructural interactions required for stable breathing may be influenced by obesity-related hormones and cytokines. Accumulating evidence strongly supports these speculations, but further intensive research is needed.

Poloxamer 188 facilitates the repair of alveolus resident cells in ventilator-injured lungs.

RATIONALE: Wounded alveolus resident cells are identified in human and experimental acute respiratory distress syndrome models. Poloxamer 188 (P188) is an amphiphilic macromolecule shown to have plasma membrane-sealing properties in various cell types. OBJECTIVES: To investigate whether P188 (1) protects alveolus resident cells from necrosis and (2) is associated with reduced ventilator-induced lung injury in live rats, isolated perfused rat lungs, and scratch and stretch-wounded alveolar epithelial cells. METHODS: Seventy-four live rats and 18 isolated perfused rat lungs were ventilated with injurious or protective strategies while infused with P188 or control solution. Alveolar epithelial cell monolayers were subjected to scratch or stretch wounding in the presence or absence of P188. MEASUREMENTS AND MAIN RESULTS: P188 was associated with fewer mortally wounded alveolar cells in live rats and isolated perfused lungs. In vitro, P188 reduced the number of injured and necrotic cells, suggesting that P188 promotes cell repair and renders plasma membranes more resilient to deforming stress. The enhanced cell survival was accompanied by improvement in conventional measures of lung injury (peak airway pressure, wet-to-dry weight ratio) only in the ex vivo-perfused lung preparation and not in the live animal model. CONCLUSIONS: P188 facilitates plasma membrane repair in alveolus resident cells, but has no salutary effects on lung mechanics or vascular barrier properties in live animals. This discordance may have pathophysiological significance for the interdependence of different injury mechanisms and therapeutic implications regarding the benefits of prolonging the life of stress-activated cells.

Effectiveness of breathing through nasal and oral routes in unconscious apneic adult human subjects: a prospective randomized crossover trial.

BACKGROUND: The authors hypothesized that mouth ventilation by a resuscitator via the nasal route ensures a more patent airway and more effective ventilation than does ventilation via the oral route and therefore would be the optimal manner to ventilate adult patients in emergencies, such as during cardiopulmonary resuscitation. They tested the hypothesis by comparing the effectiveness of mouth-to-nose breathing (MNB) and mouth-to-mouth breathing (MMB) in anesthetized, apneic, adult subjects without muscle paralysis. METHODS: Twenty subjects under general anesthesia randomly received MMB and MNB with their heads placed first in a neutral position and then an extended position. A single operator performed MNB and MMB at the target breathing rate of 10 breaths/min, inspiratory:expiratory ratio 1:2 and peak inspiratory airway pressure 24 cm H2O. A plethysmograph was used to measure the amplitude change during MMB and MNB. The inspiratory and expiratory tidal volumes during MMB and MNB were calculated retrospectively using the calibration curve. RESULTS: All data are presented as medians (interquartile ranges). The rates of effective ventilation (expired volume > estimated anatomic dead space) during MNB and MMB were 91.1% (42.4-100%) and 43.1% (42.5-100%) (P < 0.001), and expired tidal volume with MMB 130.5 ml (44.0-372.8 ml) was significantly lower than with MNB 324.5 ml (140.8-509.0 ml), regardless of the head position (P < 0.001). CONCLUSIONS: Direct mouth ventilation delivered exclusively via the nose is significantly more effective than that delivered via the mouth in anesthetized, apneic adult subjects without muscle paralysis. Additional studies are needed to establish whether using this breathing technique during emergency situations will improve patient outcomes.

Do commonly used ventilator settings for mechanically ventilated adults have the potential to embed secretions or promote clearance?

BACKGROUND: Intubation and mechanical ventilation can impair mucociliary clearance and cause secretion retention, airway occlusion, atelectasis, and pneumonia. Animal and laboratory work has demonstrated that mechanical ventilator settings can generate a flow bias (inspiratory or expiratory) that may result in mucus movement either away from the ventilator (deeper into the lungs) or toward the ventilator (toward the mouth), respectively. An absolute difference of 17 L/min, and a relative difference of ≥ 10%, between the expiratory and inspiratory flow have been reported as thresholds for mucus movement. METHODS: We measured baseline peak inspiratory and expiratory flows during quiet mechanical ventilation in a convenience sample of 20 intubated and ventilated adult patients. RESULTS: Nineteen patients had an inspiratory flow bias of ≥ 10%. Eight patients had an absolute mean inspiratory flow bias of ≥ 17 L/min. CONCLUSIONS: Commonly used mechanical ventilator settings generate an inspiratory flow bias that may promote secretion retention.

Test/retest reliability of maximum mouth pressure measurements with the MicroRPM in healthy volunteers.

BACKGROUND: Respiratory muscle strength is an important part of lung function. Assessment of the respiratory muscles' ability to generate force is important for recognizing respiratory muscle weakness in both sick and healthy people. OBJECTIVE: To assess the test/retest reliability of the MicroRPM portable manometer's measurements of maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) in the sitting and standing positions; the number of expiratory maneuvers needed with the MicroRPM for reliability in MIP and MEP measurement; and the MicroRPM's test/retest reliability in other respiratory function indices, such as the maximum rate of pressure development (MRPD), the time constant of relaxation (tau), and the maximum relaxation rate (MRR). METHODS: We recruited 15 healthy volunteers (mean age 21.6 ± 1.1 years). We assessed respiratory muscle strength on 3 separate occasions, each a week apart. We calculated reliability with the intraclass correlation coefficient (ICC), the standard error of measurement (SEM) and the smallest detectable difference (SDD). RESULTS: MicroRPM reliably measured MIP and MEP in both the sitting position (ICC 0.86-0.90, SEM 9-10, SDD 18-22) and standing position (ICC 0.78-0.83, SEM 12-14, SDD 23-26). After a 5-breath practice, 2 expiratory/inspiratory maneuvers on each testing occasion gave adequate MIP and MEP reliability (ICC > 0.90). MRR reliability was moderate to excellent (ICC 0.58-0.87), MRPD reliability was moderate (ICC 0.59-0.64), and tau reliability was insufficient (ICC 0.27-0.67). CONCLUSIONS: The MicroRPM reliably measures MIP and MEP, but its MRPD, MRR, and tau measurements should be considered with caution.

The assessment of maximal respiratory mouth pressures in adults.

Maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) are simple, convenient, and noninvasive indices of respiratory muscle strength at the mouth, but standards are not clearly established. We review recent literature, update the 2002 American Thoracic Society/European Respiratory Society statement, and propose as the best choice using a flanged mouthpiece for reference values and lower limit of normal (LLN) values as a function of age for adults age up to about 70 years. Because male pressures are higher than female and MEP exceeds MIP, we present 4 linear regression reference equations as a function of age for adults age up to approximately 70 years: Male MIP=120-(0.41xage), and male MIP LLN=62-(0.15xage). Male MEP=174-(0.83xage), and male MEP LLN=117-(0.83xage). Female MIP=108-(0.61xage), and female MIP LLN=62-(0.50xage). Female MEP=131-(0.86xage), and female MEP LLN=95-(0.57xage). (Pressure in cm H2O and age in years.) We discuss normal values in older subjects, estimation of LLN values, and the relationship between vital capacity and respiratory muscle strength, and offer a guide to interpretation of maximal pressure measurements. The approach should allow direct implementation of MIP and MEP in a pulmonary function laboratory.

Nasal patency and otorhinolaryngologic-orofacial features in children.

INTRODUCTION: Nasal obstruction is a common symptom in childhood, related to rhinitis and pharyngeal tonsil hypertrophy. In the presence of nasal obstruction, nasal patency may be reduced, and nasal breathing is replaced by mouth breathing. Orofacial and otorhinolaryngologic changes are related to this breathing mode. Objective evaluation of upper airways may be obtained through nasal patency measurement. OBJECTIVE: To compare nasal patency and otorhinolaryngologic-orofacial features in children. METHODS: One hundred and twenty three children, 6-12 year-old, and of both sexes underwent speech therapy evaluation, according to Orofacial Myofunctional Evaluation protocol, clinical and endoscopic otorhinolaryngologic examination and nasal patency measurement, using the absolute and predicted (%) peak nasal inspiratory flow values. RESULTS: Lower values of absolute and estimated peak nasal inspiratory flow values were found in children with restless sleep (p=0.006 and p=0.002), nasal obstruction report (p=0.027 and p=0.023), runny nose (p=0.004 and p=0.012), unsystematic lip closure during mastication (p=0.040 and p=0.026), masticatory speed reduced (p=0.006 and p=0.008) and altered solid food swallowing (p=0.006 and p=0.001). Absolute peak nasal inspiratory flow was lower in children with pale inferior turbinate (p=0.040), reduced hard palate width (p=0.037) and altered speech (p=0.004). Higher absolute values were found in children with increased tongue width (p=0.027) and, higher absolute and predicted (%) in children with mild everted lip (p=0.008 and p=0.000). CONCLUSIONS: Nasal patency was lower in children with restless sleep, rhinitis signs and symptoms, hard palate width reduced and with changes in mastication, deglutition and speech functions. It is also emphasized that most of the children presented signs and symptom of allergic rhinitis.

Chest wall dynamics and muscle recruitment during professional flute playing.

Respiratory parameters and sound were recorded during professional flute playing in order to assess what physiological processes were associated with the control of sound production that results in 'breath support' which in turn is associated with high quality playing. Four standing young professional flautists played flute excerpts with and without breath support. Recordings included optoelectronic plethysmographic measurements of chest wall volume (V(cw)) and its compartments, surface electromyography of the scalene, lateral abdominal, rectus abdominus, parasternal and sternocleidomastoid muscles, mouth pressure, and sound. Flow was estimated from differentiating V(cw) during playing. Results showed that flute support entails antagonistic contraction of non-diaphragmatic inspiratory muscles that tends to hold the rib cage at higher lung volume. This relieves the expiratory muscles from the task of producing the right mouth pressure, especially at the end of the phrases, so they can contribute more to the finer control of mouth pressure modulations required for high quality playing.

The inspiratory muscle training in elite rowers.

AIM: The aim of the investigation was to assess the effects of the resistive inspiratory muscle training (IMT) in elite male rowers. METHODS: Fifteen senior rowers were assayed for the maximal inspiratory mouth pressure (PImax) and maximal oxygen uptake (VO2max), and then randomized into two groups: the control and the experimental group. The latter athletes, in addition to basic training, were subjected to the 11-week IMT consisting of a series of 30 inspiratory efforts performed twice a day. Athletes from the control group did only the basic training. RESULTS: No significant relations were detected between the initial values of PImax and the VO2max value. After 6 weeks of IMT the PImax values increased by 20+/-10% (P < 0.05), whereas the final improvement (after 11 weeks of IMT) equaled to 34+/-19% (P < 0.05). In the control group, the final increase equaled to 4+/-9% and was statistically insignificant. Compared to the values obtained at the end of IMT, 14 weeks after cessation of the training PImax insignificantly decreased in the experimental group by 10+/-9%, but the measured values were still significantly higher than before the commencement of IMT. CONCLUSION: The data obtained corroborate the observations that in well-trained athletes the introduction of the principle of incremental inspiratory resistance allows to improve methodically the inspiratory muscles' strength. Once the essential period of IMT has been completed, the training volume should be reduced in order to secure the attained level of the inspiratory muscles' strength.

Specific inspiratory muscle training does not improve performance or VO2max levels in well trained rowers.

AIM: The purpose of this study was to examine the effects of specific inspiratory muscle training (IMT) on inspiratory muscle strength, maximal oxygen uptake (VO2max), maximal lactate accumulation (Lmax), dyspnea sensation and rowing performance in rowers. METHODS: Ninteen well-trained rowers were divided into two groups: IMT (T) and control (C). The T group, in addition to their daily rowing practice, performed IMT by means of a threshold inspiratory muscle trainer for approximately 0.5h.d(-1), 5 times a week for 6 weeks. The C group participated only in their regular daily rowing training. Prior to the initiation and at the completion of the 6-week IMT program, both groups underwent an incremental treadmill run test to determine VO2max. Maximum inspiratory mouth pressure (PImax) was measured at rest and following the VO2max test. On a separate occasion, rowing performance was evaluated by a 2000 m all-out effort on a rowing ergometer. Dyspnea sensation was assessed by a modified Borg scale and Lmax was measured by an enzymatic method. RESULTS: Six weeks of IMT significantly (P < 0.05) increased resting PImax. Moreover, inspiratory muscle training increased PImax following the VO2max test in the T group. In contrast, no changes in PImax were observed in the C group during the 6-week period. No significant differences were observed between pre- and post-test values in VO2max, dyspnea sensation, Lmax, and 2000 m race time in both groups. CONCLUSION: In conclusion, six weeks of IMT increases inspiratory muscle strength by approximately 28% in highly trained rowers. However, this increase in inspiratory muscle strength does not appear to improve VO2max, dyspnea sensation during exercise, or rowing performance in well-trained rowers.

Inspiratory muscle strength in chronic obstructive pulmonary disease depending on disease severity.

Staging criteria for COPD (chronic obstructive pulmonary disease) include symptoms and lung function parameters, but the role of reduced inspiratory muscle strength related to disease severity remains unclear. Therefore the present study tested whether inspiratory muscle strength is reduced in COPD and is related to disease severity according to GOLD (Global Initiative for Chronic Obstructive Lung Disease) criteria and assessed its clinical impact. PImax (maximal inspiratory mouth occlusion pressure), SnPna (sniff nasal pressure) and TwPmo (twitch mouth pressure) following bilateral anterior magnetic phrenic nerve stimulation were assessed in 33 COPD patients (8 GOLD(0), 6 GOLD(I), 6 GOLD(II), 7 GOLD(III) and 6 GOLD(IV)) and in 28 matched controls. Furthermore, all participants performed a standardized 6 min walking test. In comparison with controls, PImax (11.6+/-2.5 compared with 7.3+/-3.0 kPa; P<0.001), SnPna (9.7+/-2.5 compared with 6.9+/-3.3 kPa; P<0.001) and TwPmo (1.6+/-0.6 compared with 0.8+/-0.4 kPa; P<0.001) were markedly lower in COPD patients. TwPmo decreased with increasing COPD stage. TwPmo was correlated with walking distance (r=0.75; P<0.001), dyspnoea (r=-0.61; P<0.001) and blood gas values following exercise (r>0.57; P<0.001). Inspiratory muscle strength, as reliably assessed by TwPmo, decreased with increasing severity of COPD and should be considered as an important factor in rating disease severity and to reflect burden in COPD.

Effects of inspiratory muscle training on exercise responses in normoxia and hypoxia.

The purpose of this study was to determine the effects of inspiratory muscle training (IMT) on exercise in hypoxia (H) and normoxia (N). A 4-week IMT program was implemented with 12 healthy subjects using an inspiratory muscle trainer set at either 15% (C; n=5) or 50% (IMT; n=7) maximal inspiratory mouth pressure (PImax). Two treadmill tests (85% VO2max) to exhaustion and measures of diaphragm thickness (Tdi) and function were completed before and after training in H and N. Significant increases of 8-12% and 24.5+/-3.1% in Tdi and PImax, respectively, were seen in the IMT group. Time to exhaustion remained unchanged in all conditions. Inspiratory muscle fatigue (downward arrowPImax) following exercise was reduced approximately 10% (P<0.05) in IMT after both N and H. During H, IMT reduced (P<0.05) VO2 by 8-12%, cardiac output by 14+/-2%, ventilation by 25+/-3%; and increased arterial oxygen saturation by 4+/-1% and lung diffusing capacity by 22+/-3%. Ratings of perceived exertion and dyspnea were also significantly reduced. These data suggest that IMT significantly improves structural and functional physiologic measures in hypoxic exercise.

Prognostic value of mouth occlusion pressure in patients with chronic ventilatory failure.

BACKGROUND: Mouth occlusion pressure measurement is widely used for assessment of respiratory muscle function, particularly in patients with respiratory failure. However, its predictive value for long-term survival remains largely unexplored. METHODS: In 464 patients with chronic hypercapnic respiratory failure (CHRF) due to various underlying disorders and receiving non-invasive ventilation (NIV), maximal inspiratory mouth pressure (PI(max)), mouth occlusion pressure at 100 ms during quiet breathing (P(0.1)) and the ratio P(0.1)/PI(max) were assessed prior to and after treatment including NIV. Baseline data and changes at follow-up were used to evaluate their predictive value for long-term survival. RESULTS: Overall, median (quartiles) P(0.1) was 177.0 (109.2;287.0) %pred, PI(max) 35.0 (24.0;47.0) %pred, and P(0.1)/PI(max) 564.0 (275.7;1082.3) %pred. In multivariate analyses, P(0.1) was related to airflow obstruction, lung hyperinflation, haemoglobin (Hb) and leukocytes, and PI(max) to airflow obstruction and hyperinflation (p<0.05 each). All-cause mortality during follow-up (median 31.6 months) was 31.5%. Survival was associated with age, body-mass index (BMI), lung function, leukocytes, Hb, PI(max), P(0.1) and P(0.1)/PI(max) (p<0.01 each, univariate). Among these multivariate Cox regression identified age, BMI, FEV(1), leukocytes and P(0.1)/PI(max) as independent predictors (p<0.05 each). Furthermore, the decrease of P(0.1)/PI(max) at follow-up was associated with improved survival in patients with high baseline P(0.1)/PI(max) (>50th or 75th percentile; p<0.05). CONCLUSIONS: In patients with CHRF and current NIV therapy, P(0.1)/PI(max) was an independent predictor of long-term survival, in addition to previously established risk factors. Moreover, a decrease in P(0.1)/PI(max) after treatment including NIV was associated with an improved survival in patients with high baseline P(0.1)/PI(max) values.

Inspiratory muscle training: a simple cost-effective treatment for inspiratory stridor.

This case study describes the support given to a British elite athlete in the build up to the 2004 Athens Olympic Games. The athlete had complained of breathing symptoms during high intensity training that led to a reduction in performance and premature cessation of training. Following a negative eucapnic voluntary hyperpnoea challenge and observation during high intensity exercise, the athlete was diagnosed with inspiratory stridor. Inspiratory muscle training (IMT) was implemented to attenuate the inspiratory stridor. Following an 11-week IMT programme, the athlete had a 31% increase in mouth inspiratory pressure and a reduction in recovery between high intensity sprints. The athlete reported a precipitous fall in symptoms and was able to complete high intensity training without symptoms. This case shows that IMT is a suitable cost-effective intervention for athletes who present with inspiratory stridor.

[Possible effects of non invasive mechanical ventilation on respiratory drive and muscles]. / Possibili effetti della ventilazione meccanica non invasiva su drive e muscolatura respiratoria.

OBJECTIVE: To evaluate whether long-term Non-Invasive Mechanical Ventilation (NIMV) might have an effect on respiratory drive and respiratory muscles strength, measuring mouth occlusion pressure (P0,) and maximal inspiratory pressure (MIP). PATIENTS AND METHODS: 20 consecutive patients with hypercapnic respiratory failure underwent measurements of dyspnea, respiratory drive and respiratory muscles strength before hospital treatment with NIMV; those patients who showed significant improvement of gas-exchange continued home ventilation for a period of four weeks, and were readmitted to hospital for re-evaluation of Borg's scale for dyspnea, P0,1 and MIP. RESULTS: Data obtained show a mild reduction of P0,1 and a significant improvement of respiratory muscles strength, with satisfactory dyspnea relief. CONCLUSIONS: We conclude that unloading respiratory muscles through mechanical ventilation results in better muscle performance in the long-term that could act, together with normalization of gas-exchange, on neuromuscular respiratory drive and contribute to dyspnea relief.

Maximal inspiratory mouth pressure in Japanese elite female athletes.

Maximal inspiratory mouth pressure (MIP) is a common measurement of inspiratory muscle strength, which is often used in a variety of exercises to evaluate the effects of inspiratory muscle training. The characteristics of MIP in elite female athletes remain unclear. This study aimed to determine the characteristics of MIP at rest in a variety of sport-specific elite female athletes. We also aimed to clarify if there is a sex difference of MIP in elite athletes. We studied 169 Japanese elite female athletes and 301 Japanese elite male athletes. MIP was assessed using a portable autospirometer with a handheld mouth pressure meter. Female athletes who regularly experienced exercise-induced inspiratory muscle fatigue tended to have higher MIP values. The mean absolute MIP value in females was significantly lower than that in males. However, when this value was expressed relative to body mass, this difference disappeared. Our findings provide essential information for prescribed, sport-specific, inspiratory muscle training in elite female athletes.

Airflow Shape Is Associated With the Pharyngeal Structure Causing OSA.

BACKGROUND: OSA results from the collapse of different pharyngeal structures (soft palate, tongue, lateral walls, and epiglottis). The structure involved in collapse has been shown to impact non-CPAP OSA treatment. Different inspiratory airflow shapes are also observed among patients with OSA. We hypothesized that inspiratory flow shape reflects the underlying pharyngeal structure involved in airway collapse. METHODS: Subjects with OSA were studied with a pediatric endoscope and simultaneous nasal flow and pharyngeal pressure recordings during natural sleep. The mechanism causing collapse was classified as tongue-related, isolated palatal, lateral walls, or epiglottis. Flow shape was classified according to the degree of negative effort dependence (NED), defined as the percent reduction in inspiratory flow from peak to plateau. RESULTS: Thirty-one subjects with OSA (mean apnea-hypopnea index score ± SD, 54 ± 27 events/h) who were 50 ± 9 years of age were studied. NED was associated with the structure causing collapse (P < .001). Tongue-related obstruction (n = 13) was associated with a small amount of NED (median, 19; interquartile range [IQR], 14%-25%). Moderate NED was found among subjects with isolated palatal collapse (median, 45; IQR, 39%-52%; n = 8) and lateral wall collapse (median, 50; IQR, 44%-64%; n = 8). The epiglottis was associated with severe NED (median, 89; IQR, 78%-91%) and abrupt discontinuities in inspiratory flow (n = 9). CONCLUSIONS: Inspiratory flow shape is influenced by the pharyngeal structure causing collapse. Flow shape analysis may be used as a noninvasive tool to help determine the pharyngeal structure causing collapse.