Maximal Expiratory Mouth Pressures Research Articles

Association between expiratory mouth pressure and abdominal muscle activity in healthy young males.

To clarify the association between forced expiration and the abdominal muscles by assessing the relationship between expiratory mouth pressure and abdominal muscle activity in healthy young males. Twenty-five males underwent forced expiration at 20, 30, 50, 75, and 100% of the maximal expiratory mouth pressure. Mouth pressure was measured using a bridge-type transducer connected to a mouth pressure meter. Abdominal crunch, twist crunch, and abdominal hollowing at maximal voluntary contraction were also performed. During forced expiration and abdominal exercises, the activity of the rectus abdominis (RA), oblique externus abdominis/oblique internus abdominis (OE/OI), and OI/transversus abdominis (OI/TrA) was measured using surface electromyography. The determination coefficient (r2) for the linear relationship between mouth pressure and abdominal muscle activity was 0.86 ± 0.15 for the RA, 0.93 ± 0.06 for the OE/OI, and 0.90 ± 0.14 for the OE/OI. The slope of the linear relationship with r2 ≥ 0.50 showed no significant difference between the RA (0.22 ± 0.27) and the OE/OI (0.27 ± 0.21). However, it was significantly greater in the OI/TrA (1.78 ± 1.41) than in the RA and OE/OI. The OE/OI activity was significantly lower in the maximal forced expiration than in twist crunch, and the OI/TrA activity was not significantly greater in the maximal forced expiration than in twist crunch. All abdominal muscles contribute to forced expiration with a greater contribution of the OI and TrA than the RA and OE. Furthermore, the contribution of the TrA would be greater than that of the OI.

Effect of expiratory muscle training on respiratory muscle fatigue in healthy adults: a randomized controlled trial.

[Purpose] This study examined the effects of expiratory muscle training on fatigue in individual respiratory muscles. [Participants and Methods] Healthy adult males (n=31) were randomly assigned to two groups: expiratory muscle training (n=15) and normal controls (n=16). In the expiratory muscle training group, training was performed once for 15 min at 50% load of the maximum expiratory mouth pressure twice daily for 4 weeks. Respiratory muscle fatigue indicators were measured using surface electromyography as the median power frequency of each respiratory muscle at the time of measuring the maximum inspiratory mouth pressure during 20 min of inspiratory muscle loading and maximum expiratory mouth pressure. [Results] In the expiratory muscle training group, the median power frequency values of the sternocleidomastoid, rectus abdominis, and internal oblique/external oblique before expiratory muscle training significantly decreased during inspiratory muscle loading. However, no difference was observed in the median power frequency values measured before and during inspiratory muscle loading after the expiratory muscle training. In the normal controls, the median power frequency values of the sternocleidomastoid and rectus abdominis significantly decreased during inspiratory muscle loading. [Conclusion] Expiratory muscle training increased fatigue tolerance of the sternocleidomastoid, rectus abdominis, and internal and external oblique muscles in healthy individuals.

Deterioration of Cough, Respiratory, and Vocal Cord Functions in Patients with Multiple System Atrophy.

The purpose of this study was to clarify changes in cough function in patients with multiple system atrophy (MSA). Seventeen probable patients with MSA were studied. Peak cough flow (PCF), respiratory function (percentage of vital capacity, percentage of forced vital capacity, and percentage of predicted forced expiratory volume in one second), respiratory muscle strength (percentage of maximal inspiratory mouth pressure and percentage of maximal expiratory mouth pressure), and maximum phonation time (MPT) were assessed. Walking ability, disease duration, possibility of air stacking, Unified MSA Rating Scale (UMSARS), and Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III were also assessed. Data were separately analyzed for ambulatory and non-ambulatory groups categorized by Functional Ambulation Categories. PCF, respiratory function, respiratory muscle strength, and MPT were significantly lower in the non-ambulatory group than in the ambulatory group. On the other hand, no correlation between PCF and disease duration was observed. A significant number of patients in the non-ambulatory group were unable to hold their breath. The UMSARS and MDS-UPDRS Part III in the non-ambulatory group were significantly higher than in the ambulatory group. It was concluded that ambulatory dysfunction is associated with the decline of cough function and respiratory-related function in patients with MSA.

Obstructive Sleep Apnea and a Comprehensive Remotely Supervised Rehabilitation Program: Protocol for a Randomized Controlled Trial.

Obstructive sleep apnea (OSA) is characterized by recurrent, intermittent partial or complete obstruction of the upper respiratory tract during sleep, which negatively affects the patient's daily quality of life (QoL). Middle-aged and older men who smoke and have obesity are most at risk. Even though the use of continuous positive airway pressure (CPAP) during sleep remains the gold standard treatment, various rehabilitation methods, such as exercise, respiratory therapy, myofunctional therapy, and nutritional lifestyle interventions, also appear to be effective. Moreover, it is increasingly recommended to use alternative or additional therapy options in combination with CPAP therapy. This study aims to evaluate if a comprehensive home-based, remotely supervised rehabilitation program (tele-RHB), in combination with standard therapy, can improve OSA severity by decreasing the apnea-hypopnea index (AHI); improve objective parameters of polysomnographic, spirometric, anthropometric, and body composition examinations; improve lipid profile, maximal mouth pressure, and functional capacity tests; and enhance the subjective perception of QoL, as well as daytime sleepiness in male participants with moderate to severe OSA. Our hypothesis is that a combination of the tele-RHB program and CPAP therapy will be more effective by improving OSA severity and the abovementioned parameters. This randomized controlled trial aims to recruit 50 male participants between the ages of 30 and 60 years with newly diagnosed moderate to severe OSA. Participants will be randomized 1:1, either to a 12-week tele-RHB program along with CPAP therapy or to CPAP therapy alone. After the completion of the intervention, the participants will be invited to complete a 1-year follow-up. The primary outcomes will be the polysomnographic value of AHI, Epworth Sleepiness Scale score, 36-Item Short Form Health Survey (SF-36) score, percentage of body fat, 6-minute walk test distance covered, as well as maximal inspiratory and expiratory mouth pressure values. Secondary outcomes will include polysomnographic values of oxygen desaturation index, supine AHI, total sleep time, average heart rate, mean oxygen saturation, and the percentage of time with oxygen saturation below 90%; anthropometric measurements of neck, waist, and hip circumference; BMI values; forced vital capacity; forced expiratory volume in 1 second; World Health Organization's tool to measure QoL (WHOQOL-BREF) score; and lipid profile values. Study recruitment began on October 25, 2021, and the estimated study completion date is December 2024. Analyses will be performed to examine whether the combination of the tele-RHB program and CPAP therapy will be more effective in the reduction of OSA severity and improvement of QoL, body composition and circumferences, exercise tolerance, lipid profile, as well as respiratory muscle and lung function, compared to CPAP therapy alone. The study will evaluate the effect of a comprehensive tele-RHB program on selected parameters mentioned above in male participants. The results of this intervention could help the further development of novel additional therapeutic home-based options for OSA. ClinicalTrials.gov NCT04759456; https://clinicaltrials.gov/ct2/show/NCT04759456. DERR1-10.2196/47460.

Respiratory Muscle Strength in Patients with Coronary Heart Disease and Different Musculoskeletal Disorders

Aim. To measure respiratory muscle strength (RMS) in patients with coronary heart disease (CHD) and different musculoskeletal disorders (MSD).Material and methods. Patients were divided in four groups according to the MSD. Group I included 52 (13.4%) patients with sarcopenia, group II included 28 (7.2%) patients with osteopenia, group III included 25 (6.5%) patients with osteosarcopenia, group IV included 282 (72.9%) patients without MSD. All patients underwent the assessment of maximal expiratory (МЕР) and maximal inspiratory mouth pressures (MIP).Results. The mean RMS values were lower than the normative values, and the strength of the expiratory muscles was 1.25 times lower compared to the inspiratory muscles. Both of these parameters were within the normal range in 191 (49.3%) patients, and lower values were noted in 196 (50.7%). An isolated decrease in MIP was observed in 24.8% of patients, an isolated decrease in МЕР in 6.5%, a combined decrease in MIP and МЕР in 19.4% of patients. Comparative analysis of МЕР and MIP (depending on the MSD) did not demonstrate statistically significant differences. Lower МЕР (76.9%) and MIP (75%) values were noted mainly in the group of patients with sarcopenia. A similar pattern was notes in patients with osteosarcopenia and in patients without MSD. Normative values of RMS were observed in patients with osteopenia. Correlation analysis revealed a unidirectional relationship between RMS and the parameters of muscle function (hand grip strength, muscle area and musculoskeletal index) and a multidirectional relationship between МЕР and BMI (r -0.743, p=0.013), MIP and patient age (r -0.624, p=0.021).Conclusion. Respiratory muscle weakness was diagnosed in half of the patients with coronary heart disease. There were no statistically significant differences in RMS between patients with MSD and isolated CHD, despite lower values in the group with MSD. Correlation analysis revealed an association between RMS and muscle function.

The Efficacy of Expiratory Muscle Training during Inspiratory Load in Healthy Adult Males: A Randomized Controlled Trial.

This study aimed to evaluate the effects of expiratory muscle training (EMT) on respiratory muscle strength and respiratory distress during inspiratory load. Thirty-one healthy adult males were randomly divided into an EMT group who underwent EMT (n = 15) and a control group who did not undergo EMT (n = 16). The EMT group underwent EMT with a 50% load of maximum expiratory mouth pressure (PEmax) for 15 min, twice a day, every day, for 4 weeks. The parameter of respiratory muscle fatigue was a decrease in maximum inspiratory mouth pressure (PImax) and PEmax during 20 min of inspiratory load; thus, PImax and PEmax during inspiratory load were measured. Respiratory distress during inspiratory load was assessed using the Borg scale. These assessments were performed on the same subjects in each group before and after the 4 week study. In the EMT group, the PEmax values after the study were significantly higher than those before the study (p < 0.01). Furthermore, before the study, the PImax and PEmax values for the EMT group during inspiratory load were significantly lower than those before inspiratory load (p < 0.01). However, after the study, there was no difference in these values between during and before inspiratory load. In the EMT group, the Borg scale value during inspiratory load from 6 to 20 min was significantly lower after the study than before the study (p < 0.05). EMT increases expiratory muscle strength, thereby attenuating decreased respiratory muscle strength (PImax and PEmax) and respiratory distress during inspiratory load in healthy subjects.

Respiratory muscle sequelae in young university students infected by coronavirus disease 2019: an observational study.

The infection caused by coronavirus disease 2019 can lead to respiratory sequelae in individuals who have experienced severe or mild symptoms. An observational, cross-sectional study was developed, following the STROBE guidelines. Maximal inspiratory and expiratory mouth pressures were assessed in 50 healthy young students (26 women, 24 men; age 22.20±2.41 years). The inclusion criteria were as follows: aged between 18 and 35 years; control group: not diagnosed with coronavirus disease 2019; and coronavirus disease 2019 group: diagnosed with coronavirus disease 2019, at least 6 months ago. The exclusion criteria were as follows: obese/overweight; infected with coronavirus disease 2019 or coronavirus disease 2019 symptoms in the last 6 months; smokers; and asthmatics. When comparing with groups, the coronavirus disease 2019 group presented statistically significant lower maximal inspiratory pressure values compared with the control group (88.32±16.62 vs. 101.01±17.42 cm H2O; p=0.01). Regarding the maximal expiratory pressure, no significant differences were found. Similar results were found when performing a subgroup analysis by sex and group. Young students who suffered from coronavirus disease 2019 asymptomatically or mildly at least 6 months ago presented a significant decrease in the inspiratory muscle strength as a sequel, so we believe that patients affected by this disease should have a brief postinfection assessment of this musculature to detect the indication for cardiorespiratory rehabilitation.

Correlation and Predicted Equations of MIP/MEP from the Pulmonary Function, Demographics and Anthropometrics in Healthy Thai Participants aged 19 to 50 Years.

Objective:To identify the correlations and possible predicted equations of maximal inspiratory (MIP) and expiratory mouth pressure (MEP) values from pulmonary function test (PFT), demographics, and anthropometrics.Methods:This study involved 217 healthy participants (91 males and 126 females) aged 19 to 50 years. The PFT (forced vital capacity; FVC, forced expiratory volume in 1 second; FEV1, maximal mid-expiratory flow; MMEF, and peak expiratory flow; PEF) was performed by spirometry, whereas MIP and MEP were evaluated by a respiratory pressure meter. Pearson correlation and multiple linear regression, with the stepwise method, were used for statistical analysis.Results:The MIP and MEP had a significant positive correlation with weight, height, body mass index (BMI), and waist circumference. MIP had a significant positive correlation with FVC (%) and PEF (L/s and %), as well as a negative correlation with FEV1/FVC (ratio and %) and MMEF (%). Whereas, MEP showed a significant positive correlation with PEF (L/s and %) and negative correlation with FEV1/FVC (ratio and %) and MMEF (L/s). Finally, the predicted MIP and MEP equations were 103.988−97.70 × FEV1/FVC + 31.292 × Sex (male = 1 and female = 0) + 0.662 × PEF (%) and 47.384 + 3.603 × PEF (L/s)−9.514 × MMEF(L/s) + 30.458 × Sex (male = 1 and female = 0) + 0.534 × PEF (%), respectively.Conclusion:The respiratory muscle strengths can be predicted from the pulmonary function test, and gender data.

Effect of respiratory muscle strengthening on rowing performance

Background: Respiratory muscle training (RMT) has been proposed as a beneficial means of improving respiratory muscle strength (RMS) and respiratory muscle fatigue (RMF) in athletes.&#x0D; Aims and Objective: The aim of this study was to determine the effects of a 12-week specific RMT program on the RMS, RMF and rowing ergometer performance in highly- trained rowers.&#x0D; Materials and Methods: Twenty professional rowers aged 20-35 years were recruited for the study during the competitive period and randomly grouped into an experimental (n=11) or control (n=9) group. Baseline measurements of maximal inspiratory and expiratory mouth pressures were obtained with a portable handheld mouth pressure meter while performance was assessed by 2000m and 5000m rowing ergometer machine. Subsequently rowers in the experimental group were prescribed a novel RMT program comprising of specific breathing and abdominal muscle exercises while the control group was prescribed a “general exercise program” for non- respiratory muscles for a 12-week period. RMF was assessed by calculating the difference between the pre-exercise and post-exercise mouth pressures.&#x0D; Results: Respiratory muscle strength improved overtime in the experimental and the control group following the respective training programs (p&lt;0.05) with the experimental group showing higher RMS and lower RMF. However, there were no statistically significant differences in RMS and RMF between the two groups (P&gt;0.05). More importantly, rowing ergometer performance improved significantly in the experimental group compared to the control (p&lt;0.01).&#x0D; Conclusion: The results suggest that the novel RMT program had a significant effect in improving rowing performance, although the effect on RMS and RMF was not significant.

Mechanisms of improved exercise capacity following respiratory muscle training in athletes with cervical spinal cord injury.

Mechanisms of improved exercise capacity following respiratory muscle training in athletes with cervical spinal cord injury.

Respiratory muscle training in athletes with cervical spinal cord injury: effects on cardiopulmonary function and exercise capacity.

The effect of combined inspiratory and expiratory muscle training on resting and reflexive cardiac function, as well as exercise capacity, in individuals with cervical spinal cord injury (SCI) is presently unknown. Six weeks of combined inspiratory and expiratory muscle training enhances both inspiratory and expiratory muscle strength in highly-trained athletes with cervical SCI with no significant effect on lung function. There was a significant decrease in left-ventricular filling and stroke volume at rest in response to 45° head-up tilt, which is irreversible by respiratory muscle training. Combined inspiratory and expiratory muscle training increased peak aerobic work rate and reduced end-expiratory lung volumes during exercise, which may have implications for left-ventricular filling during exercise. To investigate the pulmonary, cardiovascular and exercise responses to combined inspiratory and expiratory respiratory muscle training (RMT) in athletes with tetraplegia, six wheelchair rugby athletes (five males and one female, aged 33±5years) completed 6weeks of pressure threshold RMT, 2 sessionsday-1 on 5daysweek-1 . Resting pulmonary and cardiac function, exercise capacity, exercising lung volumes and field-based exercise performance were assessed at pre-RMT, post-RMT and after a 6-week no RMT period. RMT enhanced maximal inspiratory (pre- vs. post-RMT: -76±15 to -106±23cmH2 O, P=0.002) and expiratory (59±26 to 73±32cmH2 O, P=0.007) mouth pressures, as well as peak expiratory flow (6.74±1.51vs. 7.32±1.60L/s, P<0.04). Compared to pre-RMT, peak work rate was higher at post-RMT (60±23 to 68±22W, P=0.003), whereas exercising end-expiratory lung volumes were reduced (P<0.017). Peak oxygen uptake increased in all athletes at post-RMT (1.24±0.40vs. 1.40±0.50lmin-1 , P=0.12). After 6weeks of no RMT all indices returned towards baseline, with peak work rate (P=0.037), peak oxygen uptake (P=0.041) and end-expiratory lung volume (P<0.034) being significantly lower at follow-up than at post-RMT. There was a significant decrease in left-ventricular end-diastolic volume and stroke volume in response to 45° head-up tilt (P=0.030 and 0.021, respectively); however, all cardiac indices in both supine and tilted positions were unchanged by RMT. Our findings demonstrate the efficacy of RMT with respect to enhancing respiratory muscle strength, lowering exercising lung volumes and increasing exercise capacity. Although the precise mechanisms by which RMT may enhance exercise capacity remain unclear, our data suggest that it is probably not the result of a direct cardiac adaptation associated with RMT.

Physiological and Pathophysiological Consequences of a 25-Day Ultra-Endurance Exercise Challenge.

Background: This case-report characterized the respiratory, cardiovascular, and nutritional/gastrointestinal (GI) responses of a trained individual to a novel ultra-endurance exercise challenge.Case Presentation: A male athlete (age 45 years; O2max 54.0 mL⋅kg-1⋅min-1) summited 100 mountains on foot in 25 consecutive days (all elevations >600 m).Measures: Laboratory measures of pulmonary function (spirometry, whole-body plethysmography, and single-breath rebreathe), respiratory muscle function (maximum static mouth-pressures), and cardiovascular structure and function (echocardiography, electrocardiography, large vessel ultrasound, and flow-mediated dilatation) were made at baseline and 48 h post-challenge. Dietary intake (four-day food diary), self-reported GI symptoms and plasma endotoxin concentrations were assessed at baseline, pre/post mid-point, pre/post end-point, and 48 h post-challenge.Results: The challenge was completed in a total exercise time of 142 h (5.3 ± 2.8 h⋅d-1), with a distance of 1141 km (42.3 ± 43.9 km⋅d-1), and energy expenditure of 80460 kcal (2980 ± 1451 kcal⋅d-1). Relative to baseline, there were post-challenge decreases in pulmonary capacities and expiratory flows (≤34%), maximum expiratory mouth-pressure (19%), and maximum voluntary ventilation (29%). Heart rate variability deteriorated, manifesting as a 48% decrease in the root mean square of successive differences and a 70% increase in the low-frequency/high-frequency ratio. Pre- to post-challenge endotoxin concentrations were elevated by 60%, with a maximum increase of 130% after a given stage, congruent with an increased frequency and severity of GI symptoms.Conclusion: The challenge resulted in pulmonary and autonomic dysfunction, endotoxaemia, and GI distress. The findings extend our understanding of the limits of physiological function and may inform medical best-practice for personnel supporting ultra-endurance events.

Characteristics of respiratory muscle fatigue upon inhalation resistance with a maximal inspiratory mouth pressure of 50.

[Purpose] Considering that respiratory muscle fatigue is a cause of respiratory failure, we aimed to clarify the characteristics of respiratory muscle fatigue under inhalation load and investigate its impact on individual respiratory muscles. [Participants and Methods] The study included 14 healthy adult male volunteers. Maximal inspiratory and expiratory mouth pressures were measured under inhalation load and while at rest. The statuses of the trapezius, sternocleidomastoid, pectoralis major, diaphragm, rectus abdominis, and external and internal abdominal oblique muscles were also assessed using electromyographic frequency analysis. [Results] The maximal inspiratory and expiratory mouth pressures decreased over time and recovered after rest. The median power frequency decreased significantly in the sternocleidomastoid and rectus abdominis muscles at maximal inspiratory and expiratory mouth pressures, respectively, under inhalation load. [Conclusion] As a characteristic of respiratory muscle fatigue, there is a possibility that decreases in maximal inspiratory and expiratory mouth pressures as a result of the inhalation load affect muscle fatigue in the sternocleidomastoid and rectus abdominis muscles.

Individual Variability in the Leg Blood Flow Response to Expiratory and Inspiratory Resistive Loading

BACKGROUND: Fatiguing inspiratory muscle work initiates the inspiratory muscle metaboreflex causing a time-dependent increase in muscle sympathetic nerve activity (MSNA) and a decrease in leg blood flow (Q[Combining Dot Above]L). Fatiguing contractions of the expiratory muscles also facilitates an increase in MSNA. However, the effect of fatiguing expiratory muscle work on Q[Combining Dot Above]L is somewhat unknown. PURPOSE: To determine the effect of expiratory resistive loading (ERL) compared to inspiratory resistive loading (IRL) on Q[Combining Dot Above]L in healthy humans. METHODS: Five healthy men (n = 2, 30 ± 6 y) and women (n = 3, 29 ± 5 y) performed ERL and IRL at 65% of maximal expiratory and maximal inspiratory mouth pressure (MEP; MIP) to task failure. Respiratory frequency was maintained at 15 breaths/min with an inspiratory duty cycle of 0.5. Q[Combining Dot Above]L (via Doppler ultrasound) and mean arterial pressure (MAP) (via finger photoplethysmography) were measured before, during and up to 3 min after ERL and IRL. Expiratory and inspiratory muscle fatigue was assessed by measuring the reduction in MEP and MIP from pre- to post-ERL and IRL. EMG was measured in each leg to ensure no muscular contraction occurred. RESULTS: Task failure occurred at 10.6 ± 2.4 min for ERL and at 20.6 ± 8.8 min for IRL; each subject performed ≥ 7 min of ERL and IRL. There was a 21 ± 4% reduction in MEP and a 7 ± 5% reduction in MIP from before to after ERL and IRL, respectively (P < 0.05). Despite an increase in group mean MAP from rest to during ERL (14 ± 14 mmHg, P = 0.035) and IRL (12 ± 6 mmHg, P = 0.021), there was no change in group mean Q[Combining Dot Above]L across time during either ERL or IRL (P > 0.05). There was, however, substantial individual subject variability in the Q[Combining Dot Above]L response to loaded breathing. During ERL, Q[Combining Dot Above]L decreased relative to baseline values at min 3 (−29 ± 20%) and min 7 (−17 ± 6%) in 2 of the 5 subjects; Q[Combining Dot Above]L increased by 15 ± 7% from rest to min 7 in the remaining 3 subjects. Similarly, there was a reduction in Q[Combining Dot Above]L from rest to min 3 (−23 ± 9%) and min 7 (−16 ± 3%) in 2 of the 5 subjects during IRL; Q[Combining Dot Above]L increased by 60 ± 26% from baseline to min 7 in the remaining 3 subjects. There was no significant change in MAP or Q[Combining Dot Above]L during ERL and IRL trials at 2% of MEP and MIP. CONCLUSION: Leg blood flow appears to decrease in some but not all healthy humans in response to ERL. Indeed, we report substantial individual variability in the leg blood flow response to both ERL and IRL.

Impact of Weekly Swimming Training Distance on the Ergogenicity of Inspiratory Muscle Training in Well-Trained Youth Swimmers

Lomax, M, Kapus, J, Brown, PI, and Faghy, M. Impact of weekly swimming training distance on the ergogenicity of inspiratory muscle training in well-trained youth swimmers. J Strength Cond Res 33(8): 2185-2193, 2019-The aim of this study was to examine the impact of weekly swimming training distance on the ergogenicity of inspiratory muscle training (IMT). Thirty-three youth swimmers were recruited and separated into a LOW and HIGH group based on weekly training distance (≤31 km·wk and >41 km·wk, respectively). The LOW and HIGH groups were further subdivided into control and IMT groups for a 6-week IMT intervention giving a total of 4 groups: LOWcon, LOWIMT, HIGHcon, and HIGHIMT. Before and after the intervention period, swimmers completed maximal effort 100- and 200-m front crawl swims, with maximal inspiratory and expiratory mouth pressures (PImax and PEmax, respectively) assessed before and after each swim. Inspiratory muscle training increased PImax (but not PEmax) by 36% in LOWIMT and HIGHIMT groups (p ≤ 0.05), but 100- and 200-m swims were faster only in the LOWIMT group (3 and 7% respectively, p ≤ 0.05). Performance benefits only occurred in those training up to 31 km·wk and indicate that the ergogenicity of IMT is affected by weekly training distance. Consequently, training distances are important considerations, among others, when deciding whether or not to supplement swimming training with IMT.

Respiratory Muscle Strength as a Predictive Biomarker for Survival in Amyotrophic Lateral Sclerosis.

Biomarkers for survival in amyotrophic lateral sclerosis (ALS) would facilitate the development of novel drugs. Although respiratory muscle weakness is a known predictor of poor prognosis, a comprehensive comparison of different tests is lacking. To compare the predictive power of invasive and noninvasive respiratory muscle strength assessments for survival or ventilator-free survival, up to 3 years. From a previously published report respiratory muscle strength measurements were available for 78 patients with ALS. Time to death and/or ventilation were ascertained. Receiver operating characteristic analysis was used to determine the cutoff point of each parameter. Each respiratory muscle strength assessment individually achieved statistical significance for prediction of survival or ventilator-free survival. In multivariate analysis sniff trans-diaphragmatic and esophageal pressure, twitch trans-diaphragmatic pressure (Tw Pdi), age, and maximal static expiratory mouth pressure were significant predictors of ventilation-free survival and Tw Pdi and maximal static expiratory mouth pressure for absolute survival. Although all measures had good specificity, there were differing sensitivities. All cutoff points for the VC were greater than 80% of normal, except for prediction of 3-month outcomes. Sequential data showed a linear decline for direct measures of respiratory muscle strength, whereas VC showed little to no decline until 12 months before death/ventilation. The most powerful biomarker for mortality stratification was Tw Pdi, but the predictive power of sniff nasal inspiratory pressure was also excellent. A VC within normal range suggested a good prognosis at 3 months but was of little other value.

Abdominal wall reconstruction for large incisional hernia restores expiratory lung function

Respiratory complications secondary to intermittent intra-abdominal hypertension and/or atelectasis are common after abdominal wall reconstruction for large incisional hernias. It is unknown if the respiratory function of this patient group is affected long term or impairs activities of daily living. We hypothesized that abdominal wall reconstruction for large incisional hernia would not lead to improved, long-term pulmonary function or respiratory quality of life. Eighteen patients undergoing open abdominal wall reconstruction with mesh for a large incisional hernia (horizontal fascial defect width >10cm) were compared with 18 patients with an intact abdominal wall who underwent colorectal resection. Patients were examined pre- and 1-year postoperatively. Examined measures included forced vital capacity, forced expiratory volume in first second, peak expiratory flow, maximal in- and expiratory mouth pressure, and 2 validated questionnaires on respiratory quality of life. In order to decrease heterogeneity, objectively examined parameters were presented relative to the predicted values, which were normality adjusted pulmonary measures. At 1-year follow-up, the abdominal wall reconstruction group showed significant improvement in percent predicted peak expiratory flow and maximal expiratory mouth pressure, whereas all other measurements of lung function remained unchanged. Respiratory quality of life did not change significantly. Patients who underwent abdominal wall reconstruction showed a significantly greater improvement of percent predicted peak expiratory flow compared with patients undergoing colorectal resection. Abdominal wall reconstruction for large incisional hernia improved long-term expiratory lung function. Respiratory quality of life did not change significantly after abdominal wall reconstruction.

Electrically induced mechanomyograms reflect inspiratory muscle strength in young or elderly subjects.

Respiratory muscle strength has been used as a tool for evaluating respiratory rehabilitation in chronic obstructive pulmonary disease. However, mouth pressure measurement evaluated by maximum expiratory mouth pressure (PEmax) or inspiratory mouth pressure (PImax) offers an indirect method for measuring respiratory muscle strength. We demonstrated the evaluation of diaphragm contractility using a mechanomyogram (MMG), which is the mechanical signal generated by the motion of the diaphragm induced by the electric stimulation of the phrenic nerve. Study participants were 21 young and 20 elderly subjects with no symptoms of respiratory disease. The elderly subjects were divided into non-smoker or smoker groups. The smoker group was defined as subjects having a Brinkman Index of greater than 300. We measured basic spirometric parameters, mouth pressure (PEmax, PImax), and diaphragmatic MMG. Diaphragmatic MMG showed more clear contrast between young subjects and elderly non-smoker or smoker subjects than the conventional method for respiratory muscle contraction (PEmax, PImax). In addition, the diaphragmatic MMG strongly correlated with inspiratory muscle strength. Diaphragmatic MMG may reflect diaphragmatic contractility more directly and sensitively than the conventional method.

Marine Lipid Fraction Pcso-524™ (lyprinol®/omega-xl®) Of The New Zealand Green-lipped Mussel Does Not Improve Pulmonary And Respiratory Muscle Function In Non-asthmatic Elite Runners

Habitual endurance training may be associated with mild airway inflammation and subsequent deterioration in lung function. It has been shown that PCSO-524™ (Lyprinol®/Omega-XL®), a supplement extracted from the New Zealand green-lipped mussel (Perna canaliculus) comprising of up to 90 essential fatty acids, can moderate airway inflammation in humans with asthma, and in a murine-model of allergic airway disease. PURPOSE: To determine whether supplementation with PCSO-524™ (Lyprinol®/Omega-XL®) can improve pulmonary and respiratory muscle function in non-asthmatic elite runners. METHODS: 16 male, non-asthmatic elite runners participated in the study. Participants completed baseline resting pulmonary and respiratory muscle function testing, then were randomly assigned to either a treatment (PCSO-524™; 1 capsule contains 50 mg n-3 polyunsaturated fatty acids and 100 mg olive oil, n = 8) or placebo (1 capsule contains 100 mg olive oil; n = 8) group. During the supplementation period, subjects ingested 8 capsules of either treatment or placebo per day for 12 weeks. Following baseline testing, pulmonary and respiratory muscle function was assessed every two weeks throughout the 12 week supplementation period. RESULTS: Significant between-subjects main effects were not observed in forced vital capacity (FVC), forced expiratory volume in 1-second (FEV1.0), forced expiratory flow from 25-75% of lung volume (FEF25-75), peak expiratory flow (PEF), maximal voluntary ventilation (MVV), maximal inspiratory mouth pressure (PImax), maximal expiratory mouth pressure (PEmax), lung diffusion capacity (DLCO), and closing volume (CV) (all p > 0.05). A significant within-subjects main effect was observed in PEmax (p = 0.0242) and DLCO (p < 0.0001). No significant within-subject main effects were observed in FVC, FEV1.0, FEF25-75, PEF, MVV, PImax, and CV (all p > 0.05). A significant treatment by time interaction was observed in FEF25-75 (p = 0.0264) and DLCO (p = 0.0247), but no other significant interactions were observed (all p > 0.05). CONCLUSION: Supplementation with PCSO-524™ (Lyprinol®/Omega-XL®) does not improve pulmonary or respiratory muscle function in non-asthmatic elite runners.

Effect of respiratory muscle training on pulmonary function and aerobic endurance in soccer players.

Few studies investigated the effects of the respiratory muscle training (RMT) in soccer although exhaustive high intensity exercise is known to lead to muscle fatigue in respiratory muscles. The purpose of this study was to investigate the effect of RMT on pulmonary function and aerobic endurance in soccer players. Eighteen male soccer players (mean age 22.2±1.4 years) participated in this study. Participants were assigned randomly to either an RMT or a control (CON) group. The RMT group performed a 15-minute endurance training of respiratory muscles twice a week for 5 weeks. The CON group did not receive RMT during this period. All participants were evaluated for aerobic endurance using 20-meter shuttle run test (20-MST), pulmonary function, maximal inspiratory mouth pressure (MIP), and maximal expiratory mouth pressure (MEP) using spirometry. There was a significant improvement in RMT group (14%) as compared to CON group (4%) in MIP measurement (P=0.04). No significant differences were observed in forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), maximum voluntary ventilation (MVV), and MEP after a five week of RMT (P>0.05). Similarly, there was no difference in 20-MST in the RMT group compared to CON group (P>0.05). We concluded that a five week of RMT increased MIP, but FVC, FEV1, MVV, MEP and aerobic endurance did not improve in soccer players. The RMT in addition to soccer training may improve MIP but not the tolerance to high intensity exercise.