Sustained Maximal Inspiratory Pressure Research Articles

Functional Sitting Balance and Anthropometric Measures Are Related to Inspiratory Muscle Performance in People with Spinal Cord Injury.

Respiratory complications are a leading cause of mortality post spinal cord injury (SCI). Along with breathing, respiratory muscles have a role in maintaining seated balance. Postinjury breathing influences respiratory muscle function. Preliminary evidence indicates a relation between respiratory muscle function and seated balance in people with chronic SCI dwelling in the community, but the relationship between balance and body habitus has not been explored. To explore the relationships among inspiratory muscle function, functional seated balance (FSB), and body habitus in people with SCI. A convenience sample of inpatients with SCI (C5-T12) aged 18 to 60 years who were using a wheelchair was recruited from November 2022 to March 2023. Those with additional neurological disorders or respiratory support were excluded. Respiratory muscle function measures included maximal inspiratory pressure (MIP), sustained MIP (SMIP), and Fatigue Index Test (FIT). FSB was scored using the Function in Sitting Test (FIST). Body habitus was assessed using the axillary: umbilical (A:U) ratio. Spearman correlations explored the relationships. Thirty-eight of 42 screened participants were eligible and participated (male, 32). Levels of injury ranged from C5 to T12. The mean (SD) age and duration of injury of the sample was 25.61 (6.68) years and 31.03 (28.69) months, respectively. SMIP and FIT correlated significantly with FSB (r s= .441, p = .01, and r s= .434, p = .006, respectively). A significant correlation between SMIP and A:U ratio (r s= -.330, p = .043) was observed. We observed a significant correlation between inspiratory pressure parameters and both functional seated balance and body habitus, adding to evidence on postural role of respiratory muscles.

Heterogeneous Treatment Effects after Inspiratory Muscle Training during Recovery from Postacute COVID-19 Syndrome.

The objective of this study is to investigate whether heterogeneous treatment effects occur for changes in inspiratory muscle strength, perceived dyspnea, and health-related quality of life after 8 wk of unsupervised home-based inspiratory muscle training (IMT) in adults with postacute coronavirus disease 2019 (COVID-19) syndrome. In total, 147 adults with self-reported prior COVID-19 either completed an 8-wk home-based IMT intervention ( n = 111, 92 females, 48 ± 11 yr, 9.3 ± 3.6 months postacute COVID-19 infection) or acted as "usual care" wait list controls ( n = 36, 34 females, 49 ± 12 yr, 9.4 ± 3.2 months postacute COVID-19 infection). Applying a Bayesian framework, we found clear evidence of heterogeneity of treatment response for inspiratory muscle strength: the estimated difference between standard deviations (SD) of the IMT and control groups was 22.8 cm H 2 O (75% credible interval (CrI), 4.7-37.7) for changes in maximal inspiratory pressure (MIP) and 86.8 pressure time units (75% CrI, 55.7-116.7) for sustained MIP (SMIP). Conversely, there were minimal differences in the SD between the IMT and the control group for changes in perceived dyspnea and health-related quality of life, providing no evidence of heterogeneous treatment effects. Higher cumulative power during the IMT intervention was related to changes in MIP ( β = 10.9 cm H 2 O (95% CrI, 5.3-16.8) per 1 SD) and SMIP ( β = 63.7 (32.2-95.3) pressure time units per 1 SD), clearly indicating an IMT dose response for changes in inspiratory muscle strength. Older age (>50 yr), a longer time postacute COVID-19 (>3 months), and greater severity of dyspnea at baseline were also associated with smaller improvements in inspiratory muscle strength. Heterogeneous individual responses occurred after an 8-wk home-based IMT program in people with postacute COVID-19 syndrome. Consistent with standard exercise theory, larger improvements in inspiratory muscle strength are strongly related to a greater cumulative dose of IMT.

Inspiratory Muscle and Functional Performance of Patients Entering Cardiac Rehabilitation after Cardiac Valve Replacement.

Limited research has examined inspiratory muscle performance (IMP) and functional performance (FP) of patients after valve replacement surgery (VRS). The purpose of this study was to examine IMP as well as several measures of FP in patients post-VRS. The study results of 27 patients revealed that patients undergoing transcatheter VRS were significantly (p = 0.01) older than patients undergoing minimally invasive or median sternotomy VRS with the median sternotomy VRS group performing significantly (p < 0.05) better than the transcatheter VRS group in the 6-min walk test, 5x sit-to-stand test, and sustained maximal inspiratory pressure. The 6-min walk test and IMP measures in all groups were significantly (p < 0.001) lower than predicted values. Significant (p < 0.05) relationships were found between IMP and FP with greater IMP being associated with greater FP. Pre-operative and early post-operative rehabilitation may improve IMP and FP post-VRS.

A temporal examination of inspiratory muscle strength and endurance in hospitalized COVID-19 patients

BackgroundThe two most common symptoms associated with COVID-19 are dyspnea and fatigue. One possible cause of such symptoms may be inspiratory muscle weakness. ObjectivesThe purpose of this study was to examine inspiratory muscle performance (IMP) from intensive care unit discharge (ICUD) to hospital discharge (HD) in patients with COVID-19 hypothesizing that IMP would be markedly depressed at both ICUD and HD. MethodsIMP was examined at ICUD and HD via the PrO2 device (PrO2 Health, Smithfield, RI) which provided the maximal inspiratory pressure (MIP), sustained MIP (SMIP), inspiratory duration (ID), and fatigue index test (FIT). Patient symptoms were assessed at ICUD, HD, and 1-month post-HD. Results30 patients (19 men, 11 women) with COVID-19 were included. The mean±SD age, BMI, and length of ICU and hospital stay was 71±11 yrs, 27.9 ± 6.3 kg/m, 9 ± 6 days, and 26±16 days, respectively. The mean±SD MIP, SMIP, ID, and FIT of the entire cohort at ICUD vs HD were 36±21 vs 40±20 cm H2O, 231±157 vs 297±182 PTU, 8.8 ± 4.2 vs 9.5 ± 4.6 s, and 9.0 ± 9.4 vs 13.1 ± 12.3, respectively, with only SMIP and FIT significantly greater at HD (p=.006 and 0.03, respectively). SMIP at HD was significantly related to resting dyspnea at HD (r=-0.40; p=.02). The SMIP and FIT of men were found to increase significantly from ICUD to HD, but no measure of IMP in the women increased significantly from ICUD to HD. At least one COVID-19-related symptom was present 1 month after HD with the most persistent symptoms being fatigue, cough, and dyspnea in 47%, 40%, and 37% of the patients, respectively. ConclusionsA significant reduction in IMP exists in patients with COVID-19 at both ICUD and HD and no measure of IMP in women was observed to increase significantly from ICUD to HD. Impaired inspiratory muscle endurance rather than strength was associated with greater dyspnea at HD.

Adherence to and impact of home-based high-intensity IMT in people with spinal cord injury: a pilot study

Study designThe pilot study was completed in 5 phases (Control and 4 phases of IMT) incorporating assessments at Baseline 1 (BL1), BL2, Follow-up 1 (F1), F2, F3, and F4.ObjectiveTo assess the adherence and impact of a daily high-intensity (80% of max) inspiratory muscle training (IMT) home program with once weekly supervision for people with spinal cord injury (SCI).SettingAssessments: research institution or zoom. IMT: participant’s home.MethodsParticipants completed daily IMT in IMT Phase 1 and 2, once weekly in IMT Phase 3, self-selected frequency in IMT Phase 4. All phases had one weekly supervised session except IMT Phase 4. Primary outcomes included adherence and a difficulty score [DS (0- not difficult to 10- the most difficult)]. Secondary outcomes included respiratory function and seated balance.ResultsData from 10 people with chronic SCI (>1 year) (Cervical level of injury: 6, AIS: A-B, injury duration: 10.9 years 95% CI [3.9, 18.1]) were used in the analysis. Participants completed 69% of their training days in IMT Phase 1 and 65% overall reporting an average DS of 7.4 ± 1.4. Only one participant completed training during IMT Phase 4. One participant’s training load was reduced due to suspected overtraining. Maximal inspiratory pressure (MIP), sustained MIP (SMIP), and total power (TP), improved significantly (p < 0.05) from BL2 to F1.ConclusionOur data suggest that people with SCI can perform high-intensity IMT at home to improve inspiratory performance. It is strongly recommended that participants be intermittently monitored for adherence and safety.ClinicalTrials.gov Registration number: NCT04210063.

Peak oxygen uptake and respiratory muscle performance in patients with chronic obstructive pulmonary disease: Clinical findings and implications.

The maximal oxygen uptake (VO2max) is the gold standard measure of aerobic exercise capacity and is an important outcome measure in patients with chronic obstructive pulmonary disease (COPD). And respiratory muscle performance is also an important functional parameter for COPD patients. In addition to the traditional respiratory muscle strength test, the Test of Incremental Respiratory Endurance has recently been introduced and validated in patients with COPD. However, the relationship between VO2 and respiratory muscle performance in COPD is not well understood. Therefore, this study investigated the correlations among VO2 and respiratory muscle performance and other functional markers in COPD. A total of 32 patients with COPD were enrolled. All study participants underwent the following assessments: cardiopulmonary exercise test, pulmonary function test, respiratory muscle strength test, peripheral muscle strength test, and bioelectrical impedance analysis. When comparing VO2peak and respiratory muscle parameters, the sustained maximal inspiratory pressure (SMIP) was the only factor with a significant relationship with VO2peak. Among other functional parameters, the forced expiratory volume in one second (FEV1) showed the strongest correlation with VO2peak. It was followed by phase angle values of lower limbs, leg extension peak torque, age, and total skeletal muscle mass. When comparing respiratory muscle performance with other functional parameters, the SMIP showed the strongest correlation with hand grip strength, followed by peak cough flow, forced vital capacity, maximal inspiratory pressure, and FEV1. The results showed that the SMIP was more significantly correlated with VO2peak than the static measurement of respiratory muscle strength. This suggests that TIRE may be a useful assessment tool for patients with COPD. Additionally, FEV1 and other functional markers were significantly correlated with VO2peak, suggesting that various parameters may be used to evaluate aerobic power indirectly.

Acute Respiratory Muscle Fatigue in Patients with Obesity Following Peak Aerobic Exercise

IntroductionRespiratory muscle (RM) performance has been theorized to contribute to exercise‐induced dyspnea, exercise intolerance, and low exercise capacity in patients with obesity. However, the impact of acute impairments in RM performance on exercise intolerance and exercise capacity in patients with obesity remains uncertain. We hypothesized, that following peak aerobic exercise, impairments in RM performance would be observed in patients with obesity.MethodsWe prospectively recruited 7 participants (recruitment is ongoing; 1 male, 6 female, Age: 42 ± 9 yrs; BMI: 47.7 ± 5.9 kg/m2; Waist Circumference: 126 ± 12.04 cm; Body Fat [%]: 50.91 ± 3.6). Diaphragm Thickness at expiration and Thickening Ratio (thickness at end‐inspiration – thickness at end‐expiration)/thickness at end‐expiration) were assessed via B‐mode ultrasound at the right 8th intercostal space while patients were in a semi‐recumbent position elevated 30 degrees from supine. Participants performed a cardiopulmonary exercise test (CPET) using a ramp treadmill protocol to peak exercise capacity. Measurements of RM performance were measured at baseline and repeated at 0‐minutes and 5‐minutes following CPET; which included Maximal Inspiratory Pressure (MIP), Sustained Maximal Inspiratory Pressure (SMIP), Inspiratory Duration (ID), Slope of the SMIP Plot (SMIP Slope), and Maximal Expiratory Pressure (MEP). Two‐Sided Paired T‐Tests were used to compare RM performance data before and after testing; statistical significance was set at p&lt;0.05.ResultsMean CPET Results: VO2peak: 19.37 ± 2.4 mL/kg/min; RER: 1.01 ± 0.11; Age Predicted Heart Rate Max [%] 87.57 ± 0.14; Ventilatory Reserve [%] 25.25 ± 18.32; VE/VCO2 Slope: 28.84 ± 4.50. Diaphragm Thickness: 2.8 ± 0.24 mm and Thickening Ratio: [%]: 75.47 ± 25.97. When comparing Baseline to 0‐minues following CPET significant reductions in MIP, SMIP, and MEP were observed: MIP (94.57 ± 25.01 cmH2O vs. 72.29 ± 22.09 cmH2O p = 0.02); SMIP (524.14 ± 198.85 PTU vs. 418.43 PTU p = 0.04); MEP (73.71 ± 17.10 cmH2O vs. 62.29 ± 12.83 cmH2O p= 0.02). A reduction in ID (10.6 ± 2.30 vs 8.99 sec p= 0.06) and an increase in SMIP Slope (9.2 ± 3.39 vs. 9.74 ± 3.30 p= 0.74) were observed at 0‐minutes following CPET compared to baseline but were not significant. At 5‐minutes following CPET, significant reductions in MIP (67.3 cmH2O ± 12.6 p= 0.01) and MEP (62.57 ± 14.47 cm H2O p= 0.01) were observed but not for other measures of RM performance.ConclusionOur results suggest that patients with obesity demonstrate significant reductions in RM performance following peak aerobic exercise which may persist even after recovery. Interestingly, at baseline, the patients with obesity in this study demonstrated relatively normal RM performance, diaphragm thickness and thickening ratio. Acute fatigue of the respiratory muscles may contribute to the exercise induced dyspnea, exercise intolerance and low exercise capacity observed in patients with obesity.

Inspiratory Muscle Performance Is Related to Seated Balance Function in People With Spinal Cord Injury: An Observational Study

ObjectiveTo examine the relationship between inspiratory muscle performance (IMP) and functional sitting balance (FSB) in persons with chronic spinal cord injury (SCI). We hypothesized that a moderate correlation would be found between IMP and FSB and that individuals with better balance would have better IMP. DesignThe SCI-specific modification of the Function in Sitting Test (FIST-SCI) measured FSB. The IMP measures included (1) maximal inspiratory pressure (MIP), (2) sustained MIP (SMIP), and (3) inspiratory duration. Upper extremity motor score (UEMS) and level of injury (LOI) were taken from International Standards for Neurological Classification of Spinal Cord Injury examinations. Spearman correlational analyses assessed relationships among these factors in the sample (N=37). Mann-Whitney U tests explored differences between 2 comparison group pairs (tetraplegia group [TG] vs paraplegia group [PG]; independent transfer group [ITG] vs assisted transfer group [ATG]). Regression analysis examined variables predictive of FSB in the TG. SettingResearch facility. ParticipantsVolunteers with tetraplegia (n=21, American Spinal Injury Association Impairment Scale (AIS) A=8, B=7, C=6) and paraplegia (n=16, AIS A=9, B=4, C=3) (N=37). InterventionNot applicable. Main Outcome MeasuresIMP, LOI, UEMS, FIST-SCI. ResultsUEMS, MIP, SMIP, and LOI had moderate to high correlations with FIST-SCI scores (ρ=0.720 (P<.001), 0.480 (P=.003), 0.467 (P=.004), 0.527 (P=.001), respectively). UEMS, MIP, and FIST-SCI scores were higher in the PG and ITG than the TG and ATG, respectively (PG vs. TG P values=<.001, .008, .002, respectively, and ITG vs. ATG P values=<.001, .032, <.001, respectively). Further, SMIP and UEMS predicted FIST-SCI balance scores in the TG, accounting for 55% of total variance (P<.001) (FIST-SCI=11.88+0.03 [SMIP]+0.425 [UEMS]). ConclusionsThe relationship between IMP and balance appears preserved after SCI. FSB was predicted, in part, via UEMS and SMIP in the TG. Future research should focus on the effect of SCI-based breathing interventions on FSB.

Abstract 13927: Sustained Maximal Inspiratory Pressure: A Novel Measure of Inspiratory Muscle Performance and Its Relationship to Physiology and Function in Heart Failure

Introduction: The sustained maximal inspiratory pressure (SMIP) is a novel measure of inspiratory muscle performance that reflects the ability of the inspiratory muscles to maintain force over time from residual volume (RV) to total lung capacity (TLC) and has been described as single-breath work capacity. In chronic obstructive pulmonary disease SMIP has been found to be more highly correlated to a greater number of physiologic and functional measures than maximal inspiratory pressure (MIP). This study examined the relationship of SMIP and MIP to a variety of physiologic and functional measures in patients with heart failure (HF). Methods: Fifty male Veterans (mean±SD age, BMI, LVEF = 69.9±8.0 years, 33.6±7.2 kg/m 2 , 40.1±14.4%, respectively) with HF underwent measurement of MIP and SMIP with the PrO2 device (Smithfield, RI) which were measured from RV during initial inhalation and to TLC, respectively. Pulmonary function and maximal expiratory pressure (MEP) were also assessed. Exercise capacity was assessed via cardiopulmonary exercise testing (CPET) and leg strength testing. Physical function was assessed with grip strength, 6-minute walk distance (6MWD), and sit-to-stand test (STS). Results: The mean±SD MIP and SMIP were 66.3±24.8 cmH 2 O and 351.3±151.4 PTU, respectively. Both MIP and SMIP were significantly (p&lt;0.05) correlated to many physiologic (r=.33-.48) and functional measures (r=.38-.62) with the greatest correlate to MIP being MEP (r=.58) and the greatest correlate to SMIP being FEV 1 (r=.62). The greatest physiologic correlate to MIP and SMIP was CPET peak tidal volume with identical r-values (.48). Absolute and relative peak oxygen consumption (pVO 2 ) were correlated to both MIP and SMIP with identical r-values for absolute pVO 2 (.33) and slightly higher r-values between MIP and relative pVO 2 (.37 vs .34). The greatest functional correlate to MIP and SMIP was leg strength/endurance (r=.53 and .46, respectively) followed by STS (r=.52 and .45, respectively) and 6MWD (r=.49 and .45, respectively). Conclusions: MIP and SMIP are significantly correlated in a positive direction to many physiologic and functional measures supporting the role of inspiratory muscle training and further study of SMIP and MIP in HF.

Inspiratory Muscle Performance and Anthropometric Measures—Novel Assessments Related to Pulmonary Function in People with Spinal Cord Injury: A Pilot Study

ObjectiveTo investigate the feasibility and validity of using the novel axillary:umbilical (A:U) ratio and sustained maximal inspiratory pressure (SMIP) as supplementary measures in the assessment of respiratory function in people with spinal cord injury. DesignPilot study with a single day of data collection. All measurements were taken with participants in their personal wheelchairs to best represent normal functioning and positioning for each individual. SettingResearch institution. ParticipantsA convenience sample of 30 community dwelling volunteers with chronic spinal cord injury (C2-T12, American Spinal Injury Association Impairment Scale A-D) participated. InterventionsNot applicable. Main Outcome MeasuresParticipants underwent anthropometric measurements (trunk height, abdominal circumference, axillary circumference) and assessment of inspiratory muscle performance, incluidng maximal inspiratory pressure, SMIP, and inspiratory duration, as well as standard pulmonary function tests. ResultsThe A:U ratio and SMIP were recorded for all participants. The SMIP was significantly related to more respiratory performance measures than the maximal inspiratory pressure (P<.05) and the A:U ratio was significantly related to more respiratory performance measures than any other anthropometric measure (P<.05). Additionally, an A:U ratio cutoff point detected individuals with a peak expiratory flow ≥ 80% of their predicted value with a sensitivity and specificity of 85.7% and 91.3%, respectively (area under the curve: 0.92). ConclusionsIt is feasible to capture the A:U Ratio and SMIP in individuals with spinal cord injury. Further, the strong significant relationships of SMIP and the A:U ratio to respiratory performance measures suggests their clinical importance in the pulmonary assessment and risk stratification of people with chronic spinal cord injury.

The Effect of a High-Intensity PrO2Fit Inspiratory Muscle Training Intervention on Physiological and Psychological Health in Adults with Bronchiectasis: A Mixed-Methods Study.

Bronchiectasis is characterised by airflow obstruction and hyperinflation resulting in respiratory muscle weakness, and decreased exercise capacity. Inspiratory muscle training (IMT) is potentially an alternative treatment strategy to enhance respiratory muscle strength and endurance. Therefore, the aim was to investigate the effects of IMT on those with bronchiectasis. Eighteen participants (10 bronchiectasis) took part in an eight-week, three times a week IMT programme at 80% sustained maximal inspiratory pressure (SMIP). Lung function, respiratory muscle strength and endurance, exercise capacity, physical activity and self-determination theory measures were taken. Participants also took part in a semi-structured interview to assess their perceptions and experience of an IMT intervention. After eight weeks of IMT, bronchiectasis and healthy participants exhibited significant increases in MIP (27% vs. 32%, respectively), SMIP (16% vs. 17%, respectively) and inspiratory duration (36% vs. 30%, respectively). Healthy participants exhibited further improvements in peak expiratory flow and maximal oxygen consumption. Bronchiectasis participants reported high levels of perceived competence and motivation, reporting higher adherence and improved physical ability. Eight weeks of IMT increased inspiratory muscle strength and endurance in those with bronchiectasis. IMT also had a positive effect on perceived competency and autonomy, with bronchiectasis participants reporting improved physical ability and motivation, and high adherence.

The Impact of Yoga on Inspiratory Muscle Performance in Veterans with COPD: A Pilot Study.

Chronic obstructive pulmonary disease (COPD) causes respiratory muscle weakness that leads to disabling dyspnea and poor functional performance. Therapies are often geared to improve inspiratory muscle performance. Yoga has been shown to improve exercise capacity, quality of life, and some pulmonary function measures in COPD, but little research has examined the effects of yoga training on inspiratory muscle performance. The purpose of this study was to investigate the effects of yoga training on inspiratory muscle performance in military veterans using the Test of Incremental Respiratory Endurance (TIRE). A prospective pilot study examined a 6-week yoga training program consisting of asana (poses) and pranayama (controlled breathing). Subjects had baseline inspiratory muscle weakness. The TIRE measured inspiratory muscle performance via the PrO2 device, providing maximal inspiratory pressure, sustained maximal inspiratory pressure, and inspiratory duration. Secondary measures included 6-minute walk distance, St. George Respiratory Questionnaire, Hospital Anxiety and Depression Scale, and spirometry. Mean age and BMI of subjects were 67 ± 3.6 years and 20.7 ± 3.3, respectively. The majority of subjects had severe (28.7%) or very severe (57.1%) COPD. Statistically significant improve m e n t s were seen in maximal inspiratory pressure (39.0 ± 14.1 cmH2O to 56.4 ± 20.6 cmH2O) and sustained maximal inspiratory pressure (244.1 ± 100.6 PTU to 308.1 ± 121.2 PTU). No statistically significant improvements we re observed in 6-minute walk distance, St. George Respiratory Questionnaire, Hospital Anxiety and Depression Scale, or spirometry. Yoga training has the potential in improve inspiratory muscle performance in veterans with severe to very severe COPD who present with inspiratory muscle weakness. This is of importance because improving inspira-tory muscle performance has been shown to improve COPD outcomes.

Inspiratory Muscle Training: Improvement of Exercise Performance With Acute Hypoxic Exposure.

To determine whether chronic IMT improves submaximal-exercise performance with acute hypoxic exposure. A total of 14 endurance-trained men completed a 20-km cycling time trial (TT) in normobaric hypoxia (fraction of inspired oxygen [FiO2] = 0.16) before and after either 6 wk of an IMT protocol consisting of inspiratory loads equivalent to 80% of sustained maximal inspiratory pressure (n = 9) or a SHAM protocol (30% of sustained maximal inspiratory pressure; n = 5). In the IMT group, 20-km TT performance significantly improved by 1.45 (2.0%), P = .03, after the 6-wk intervention. The significantly faster TT times were accompanied by a higher average V˙E (pre vs post: 99.3 [14.5] vs 109.9 [18.0]L·min-1, P = .01) and absolute oxygen uptake (pre vs post: 3.39 [0.52] vs 3.60 [0.58]L·min-1, P = .010), with no change in ratings of perceived exertion or dyspnea (P > .06). There were no changes in TT performance in the SHAM group (P = .45). These data suggest that performing 6 wk of IMT may benefit hypoxic endurance exercise performance lasting 30-40min.

Effects of Inspiratory Exercise With Linear and Nonlinear Load on Respiratory Variables Post-Bariatric Surgery.

Obesity leads to changes in respiratory function, causing reduced lung volumes and mechanical disadvantage of the respiratory muscles. We sought to evaluate the effect of breathing exercises using devices that impose linear and nonlinear load on reversing diaphragm dysfunction and the prevalence of atelectasis after bariatric surgery. This was a blind randomized clinical trial. Preoperatively, we assessed the subjects' maximum inspiratory pressure by measuring nasal inspiratory pressure and respiratory muscle endurance with an incremental test based on sustained maximum inspiratory pressure (sustained PImax) and the prevalence of atelectasis by chest radiograph. Subjects were then randomized into 2 groups: a linear load pressure group and nonlinear load pressure group; both groups received conventional respiratory physiotherapy. Subjects were reassessed on the second day after bariatric surgery. We included 40 morbidly obese women (body mass index > 40 kg/m2), age 25-55 years, who underwent bariatric surgery by laparotomy. The groups were homogeneous with respect to age (P = .11), body mass (P = .12), height (P = .75), body mass index (P = .75), nasal inspiratory pressure (P = .48), sustained PImax (P = .89), and absence of atelectasis at baseline. In the reassessment, both groups showed significant reduction in nasal inspiratory pressure (P < .001) and maintenance of sustained PImax (linear load pressure P = .51; nonlinear load pressure P = .055). The prevalence of atelectasis was 15% for linear load pressure and 25% for nonlinear load pressure, with no significant difference between groups (P = .69). Both groups were able to maintain respiratory muscle endurance after bariatric surgery. In addition, the treatment contributed to controlling atelectasis so that it did not cause clinical repercussions to the subjects. (ClinicalTrials.gov registration NCT02298517).

Inspiratory loading exercises on respiratory muscle function in post-operative gastroplasty patients: a randomized clinical trial

Abstract Introduction: The gastroplasty post-operative period can alter respiratory mechanics and predispose patients to respiratory complications. Objective: The objective was to evaluate the effects of exercises with inspiratory load on respiratory muscle function and on the prevalence of atelectasis after gastroplasty. Method: 40 participants were randomly allocated into two groups: Control Group (CG), its members underwent conventional respiratory physical therapy (CRP) and the Inspiratory Load Group (ILG), its members performed exercises with linear inspiratory pressure load, with 40% of the maximum inspiratory pressure (MIP), associated with CRP. Therapy procedures were conducted twice during the immediate post-operative period and thrice on the first post-operative day. In addition to evaluating the MIP, the nasal inspiratory pressure (NIP) and the sustained maximum inspiratory pressure (SMIP) were evaluated before and after treatment. Analysis of variance followed by the Bonferroni correction were applied considering a 5% significance level (p &lt; 0.05). Results: There was no significant difference in NIP and SMIP values when the pre- and post-operative periods were compared for the ILG; however, these values were significantly lower for the CG, also with intergroup differences in NIP values. Atelectasis prevalence was 5% for ILG and 15% for CG, with no intergroup difference. Conclusion: The inspiratory muscle strength and resistance of the respiratory muscles were maintained in the group that performed exercises with inspiratory load associated with CRP, with a low rate of atelectasis after gastroplasty.

The BODE index and inspiratory muscle performance in COPD: Clinical findings and implications.

Objectives:The Test of Incremental Respiratory Endurance is a novel testing method that provides a unique examination of one’s inspiratory muscle strength, work and endurance. Little is known about the relationship between inspiratory muscle performance and mortality risk in obstructive lung disease. We examined the relationship between the Test of Incremental Respiratory Endurance measures and the Body-mass index, airflow Obstruction, Dyspnea and Exercise index in chronic obstructive pulmonary disease.Methods:In all, 70 males with mild-to-very severe chronic obstructive pulmonary disease (mean ± standard deviation of 70.2 ± 5.9 years) underwent measurements of body-mass index, spirometry, dyspnea and a 6-min walk test from which the Body-mass index, airflow Obstruction, Dyspnea and Exercise score was calculated. The Test of Incremental Respiratory Endurance provided measures of maximal inspiratory pressure, sustained maximal inspiratory pressure and inspiratory duration.Results:All Test of Incremental Respiratory Endurance parameters inversely correlated with the Body-mass index, airflow Obstruction, Dyspnea and Exercise score: maximal inspiratory pressure (r = −0.355, p = 0.00), sustained maximal inspiratory pressure (r = −0.426, p = 0.00) and ID (r = −0.278, p = 0.02), with sustained maximal inspiratory pressure displaying the highest correlation. Independent significant correlations were also observed between the sustained maximal inspiratory pressure and all Body-mass index, airflow Obstruction, Dyspnea and Exercise score components, except for body-mass index. Finally, sustained maximal inspiratory pressure was significantly different among the Body-mass index, airflow Obstruction, Dyspnea and Exercise index quartiles.Discussion:The significant association between the Body-mass index, airflow Obstruction, Dyspnea and Exercise score and inspiratory muscle performance, in particular sustained maximal inspiratory pressure, suggests that these measures may have a potential prognostic value in the evaluation of chronic obstructive pulmonary disease.

Inspiratory Muscle Performance of Former Smokers and Nonsmokers Using the Test of Incremental Respiratory Endurance.

Smoking has potential deleterious effects on respiratory muscle function. Smokers may present with reduced inspiratory muscle strength and endurance. We compared inspiratory muscle performance of nonsmokers with that of former smokers without overt respiratory problems via the Test of Incremental Respiratory Endurance. This study was performed on 42 healthy subjects between the ages of 30 and 79 y (mean ± SD of 56.5 ± 14.4 y). Fourteen male and 7 female former smokers were matched to nonsmokers based on sex, age, height, and weight. Subjects completed a questionnaire about their health and current smoking status. Testing included the best of 3 or more consistent trials. The Test of Incremental Respiratory Endurance measurements included maximal inspiratory pressure measured from residual volume as well as sustained maximal inspiratory pressure and inspiratory duration measured from residual volume to total lung capacity during a maximal sustained inhalation. No significant difference in inspiratory performance of the entire group of former smokers compared with nonsmokers was found. However, separate sex analyses found a significant difference in sustained maximal inspiratory pressure between male former smokers and nonsmokers (518.7 ± 205.0 pressure time units vs 676.5 ± 255.2 pressure time units, P = .041). We found similar maximal inspiratory pressure between former smokers and nonsmokers via the Test of Incremental Respiratory Endurance, but the significant difference in sustained maximal inspiratory pressure between male former smokers and nonsmokers suggests that the sustained maximal inspiratory pressure may have greater discriminatory ability in assessing the effects of smoking on inspiratory muscle performance. Further investigation of the effects of smoking on inspiratory performance via the Test of Incremental Respiratory Endurance is warranted.

Inspiratory Muscle Performance is Significantly Related to Agility and Speed in Collegiate Tennis Players

The Illinois Agility Test (IAT) measures sport agility by combining multi-directional skills with sprints. The Test of Incremental Respiratory Endurance (TIRE) evaluates inspiratory muscle strength and endurance via Maximal Inspiratory Pressure (MIP) and Sustained Maximal Inspiratory Pressure (SMIP). The relationship between athletic agility and inspiratory muscle performance (IMP) is unclear. PURPOSE: To examine the association between IMP and IAT results of Collegiate Tennis Players (CTP). METHODS: IMP of 7 male CTP (mean ± SD age = 20.3 ± 0.8 years, height = 186.2 ± 3.4 cm, and weight = 77.7 ± 6.5 kg) and 8 female CTP (age = 20.9 ± 0.8 years, height = 168.9 ± 6.2 cm, and weight = 64.7 ± 6.5 kg) was assessed via TIRE with the best of 3–5 trials providing MIP [measured from residual volume (RV)] and SMIP (measured from RV to total lung capacity). The IAT was performed twice with a 10-min rest between trials. The first and last intervals of the IAT comprised sprints to and from cones set 10 m apart, while the second interval involved weaving back and forth through four cones placed 3.3 m apart. A custom mobile app and tablet were used to time each IAT interval. RESULTS: MIP and SMIP of men were significantly (p<.05) greater than women (134.5 ± 19.4 vs. 99.5 ± 35.3 cm H2O and 791.1 ± 193.9 vs. 471.7 ± 162.8 PTU, respectively). Men were significantly (p<.05) faster during all IAT intervals and had a significant (p<.05) negative correlation between MIP and last sprint times of both trials (r = - .77 and - .89, respectively). In women, significant (p<.05) negative correlations existed between weaving time and SMIP of the first trial (r = - .77) and MIP and SMIP of the second trial (r = - .93 and - .89, respectively). CONCLUSIONS: IMP was significantly correlated to IAT time in CTP but gender differences existed. The correlation between MIP and last sprints in men suggests that men depend on IMP for speed. MIP and SMIP were related to the weave interval in women suggesting that women depend more on IMP for agility. Stronger correlations existed between IMP and IAT during the second IAT trials suggesting that greater IMP provides less susceptibility to performance decrement associated with fatigue. Greater IMP may provide greater balance and contribute to greater agility in women and speed in men, resulting in improved performance in CTP.

Reproducibility of inspiratory muscle endurance testing using PowerBreathe for COPD patients.

Assessing the strength and endurance of respiratory muscles is fundamental for characterizing respiratory muscle dysfunction. Although a variety of tests are used to evaluate respiratory muscle endurance, not all of them are applicable in clinical practice. Assessments can be made using a practical device called PowerBreathe®, but its reproducibility has not been tested in chronic obstructive pulmonary disease (COPD) patients. To verify the reproducibility of the inspiratory muscle endurance test using a manometer and PowerBreathe® in COPD patients. A cross-sectional study was used. In total, 19 moderate-severe COPD patients, male and female, aged 50 to 80years took part in the research. This evaluation consisted of 2 tests: an incremental test and a constant one held on the same day and repeated after 48hr. The incremental test started with 10-cm H2 O, adding 10-cm H2 O every 2min and taking 1min of rest before increasing the load. The highest load that could be sustained for at least 1min was considered the sustained maximum inspiratory pressure (SMIP) value. The constant test was performed at an intensity of 80% of the SMIP and the maximum time limit was 30min. In the incremental test, there was a significant increase in the SMIP compared to the test-retest (61±24/64.7±23.8; p=.015); the value of the relative reproducibility was 0.96, the standard error of the absolute measurement was 4.7 (95% confidence interval 9.2), and the minimum detectable difference was 10.9. In the Bland-Altman analysis, the mean error was 4.2 (confidence interval -7.6 to 16.1). The constant test was not reproducible. It was observed that the incremental test was reproducible to evaluate inspiratory muscle endurance in COPD patients. Furthermore, 2 tests needed to be carried out due to the learning effect.

Special training of inspiratory muscles in fitness activities and exercise capacity in young women

PurposeThe aim of the study was to determine if an 8-week-long endurance fitness training with elastic belts would increase the strength-endurance of the inspiratory muscles and lung function characteristics, and to assess whether these changes were consistent with an increase in aerobic power and exercise capacity in healthy young women.MethodsTwenty-two females aged 20–25 years were randomly allocated into 2 groups. The experimental group preformed 8-week-long exercises on stationary bikes with an elastic belt on the lower part of the chest. The control group underwent the same workout, without elastic belts. Vital capacity, forced vital capacity, maximal voluntary ventilation, maximal inspiratory and expiratory pressure, sustained maximal inspiratory pressure, physical activity status, and perceived exertion scores were measured. In the incremental exercise test, work capacity and maximal oxygen uptake were assessed. Tidal volume, minute ventilation (VE), oxygen uptake (VO&lt;sub&gt;2&lt;/sub&gt;), VE/VO&lt;sub&gt;2&lt;/sub&gt;, heart rate (HR), and VO&lt;sub&gt;2&lt;/sub&gt;/HR were continuously monitored. The cycle performance at the power of the ventilatory threshold was evaluated on the following day.Results. The fitness training with elastic belts significantly improved the strength and strength-endurance of the inspiratory muscles, the functional cardio-respiratory capabilities, and aerobic work output. In the control group, the studied parameters were not significantly increased.ConclusionsApplying elastic belts to fitness endurance exercises improves the strength and strength-endurance of inspiratory muscles, cardio-respiratory capabilities, and aerobic power, which additionally raises aerobic work output in fitness training of young women.