Maximal Inspiratory Pressure and Maximal Expiratory Pressure in Healthy Korean Children

Unveiling the Respiratory Muscle Strength in Duchenne Muscular Dystrophy: The Impact of Nutrition and Thoracic Deformities, Beyond Spirometry

BACKGROUND/OBJECTIVES

Duchenne muscular dystrophy (DMD) is the most prevalent progressive muscular dystrophy, and the guidelines recommend the regular assessment of respiratory muscle function. This study aimed to assess the relationship between maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP) and sniff nasal inspiratory pressure (SNIP) measurements and upright-supine spirometry parameters in children with DMD, the predictability of upright-supine spirometry in terms of diaphragm involvement, and the impact of nutrition on muscle strength.

METHODS

This prospective cross-sectional study examined patients with DMD by comparing upright and supine FVC, MIP, MEP, and SNIP measurements. The effects of the ambulatory status, kyphoscoliosis, chest deformity, and low BMI on respiratory parameters were investigated.

RESULTS

Forty-four patients were included in the study. The mean patient age was 10.8 ± 2.9 years. Twenty-five patients were ambulatory. A significant decrease in FVC, FEV1, and FEF25-75 values was detected in the supine position in both ambulatory and non-ambulatory patients (p < 0.05). All patients had low MIP, MEP, and SNIP measurements (less than 60 cm H2O). MIP, MEP, and SNIP values were significantly lower in patients with a low BMI than in those without (p < 0.05).

CONCLUSIONS

To accurately assess respiratory muscle strength, supine FVC should be combined with upright FVC, MIP, MEP, and SNIP measurements. It is crucial to regularly screen patients for nutrition, as this can significantly affect respiratory muscle function during pulmonology follow-up.

Normal values for maximal respiratory pressures in children and adolescents: A systematic review with meta-analysis

BACKGROUND

The non-invasive assessment of maximal respiratory pressures (MRP) reflects the strength of the respiratory muscles.

OBJECTIVE

To evaluate the studies which have established normative values for MRP in healthy children and adolescents and to synthesize these values through a meta-analysis.

METHODS

The searches were conducted until October 2023 in the following databases: ScienceDirect, MEDLINE, CINAHL, SciELO, and Web of Science. Articles that determined normative values and/or reference equations for maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) in children and adolescents published in English, Portuguese, or Spanish regardless of the year of publication were included. Two reviewers selected titles and abstracts, in case of conflict, a third reviewer was consulted. Articles that presented sufficient data were included to conduct the meta-analysis.

RESULTS

Initially, 252 studies were identified, 28 studies were included in the systematic review and 19 in the meta-analysis. The sample consisted of 5798 individuals, and the MIP and MEP values were stratified by sex and age groups of 4-11 and 12-19 years. Values from females 4-11 years were: 65.8 cmH2O for MIP and 72.8 cmH2O for MEP, and for males, 75.4 cmH2O for MIP and 84.0 cmH2O for MEP. In the 12-19 age group, values for females were 82.1 cmH2O for MIP and 90.0 cmH2O for MEP, and for males, they were 95.0 cmH2O for MIP and 105.7 cmH2O for MEP.

CONCLUSIONS

This meta-analysis suggests normative values for MIP and MEP in children and adolescents based on 19 studies.

Reference Respiratory Muscle Strength Values and a Prediction Equation Using Physical Functions for Pulmonary Rehabilitation in Korea

BACKGROUND

In Korea, tests for evaluating respiratory muscle strength are based on other countries' clinical experience or standards, which can lead to subjective evaluations. When evaluating respiratory function based on the standards of other countries, several variables, such as the race and cultures of different countries, make it difficult to apply these standards. The purpose of this study was to propose objective respiratory muscle strength standards and predicted values for healthy Korean adults based on age, height, weight, and muscle strength, by measuring maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and peak cough flow (PCF).

METHODS

This cross-sectional study analyzed MIP, MEP, and PCF in 360 people, each group comprising 30 adult men and women aged 20-70, diagnosed as healthy after undergoing medical check-ups at a general hospital. Hand grip strength (HGS) and the five times sit-to-stand test (FTSST) results were also recorded. Correlations among respiratory muscle strength, participant demographics, and overall muscle strength were evaluated using Pearson's correlation analysis. The predicted values of respiratory muscle strength were calculated using multiple regression analysis.

RESULTS

Respiratory muscle strength differed from the values reported in studies from other countries. In the entire samples, both MIP and MEP had the highest correlations with peak HGS (r = 0.643, r = 0.693; P < 0.05), while PCF had the highest correlation with forced expiratory volume in 1 s (r = 0.753; P < 0.05). Age, body mass index, peak HGS, and FTSST results were independent variables affecting respiratory muscle strength. A predictive equation for respiratory muscle strength was developed using the multiple regression equation developed in this study.

CONCLUSION

Respiratory muscle strength index may differ by country. For more accurate diagnoses, standard values for each country are required. This study presents reference values for Korea, and a formula for estimation is proposed when no respiratory muscle strength measurement equipment is available.

TRIAL REGISTRATION

Clinical Research Information Service Identifier: KCT0006778.

Association between Anterior Surgical Approach and Dysphagia Severity in Patients with Cervical Spinal Cord Injury

INTRODUCTION

Early detection and management of dysphagia are essential for preventing aspiration pneumonia and reducing mortality in patients with cervical spinal cord injury (C-SCI). In this study, we identified risk factors for dysphagia in patients with C-SCI by analyzing the correlation between the clinical factors and the severity of dysphagia, not the presence or absence of dysphagia. Combined with the analysis results of previous studies, we thought that this additional analysis method could more accurately reveal the risk factors for dysphagia in patients with C-SCI.

METHODS

The presence and severity of dysphagia in patients with C-SCI was evaluated using a modified videofluoroscopic dysphagia scale (mVDS) and penetration-aspiration scale (PAS). All included patients with C-SCI performed a video fluoroscopic swallowing study (VFSS). Clinical factors such as age, sex, the presence of tracheostomy, spinal cord independence measure (SCIM), pulmonary function test (PFT), including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FVC/FEV1, maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP), American Spinal Cord Injury Association (ASIA) score, Berg Balance Scale (BBS), and operation method were investigated.

RESULTS

In the multivariate regression analysis, the anterior surgical approach was the only clinical factor that had a significant correlation in both mVDS and PAS, which represents the severity of dysphagia in C-SCI patients (p < 0.05).

CONCLUSION

The anterior surgical approach was correlated with the severity of dysphagia in patients with C-SCI. Considering this, as one of the risk factors affecting dysphagia in patients with C-SCI, surgical method may also need to be considered. Additionally, we recommend that clinicians should pay particular attention to the potential for development of dysphagia in patients who received anterior cervical surgery. However, further prospective studies with larger sample sizes are needed for more accurate generalization.

Respiratory Muscle Strength in Healthy Indian Children of Age 7-17 Years: A Cross-Sectional Study

Purpose

As the values of respiratory muscle strength vary according to race, ethnicity, and geographical area, there is a wide-ranging difference among different populations. Thus, the available reference values may not have an application for use in the Indian paediatric population, creating a need for generating values which will be appropriate for the Indian paediatric context.

Materials and Methods

Assessment of respiratory muscle strength was carried out by assessing maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) and synthesising predictive formulas using anthropometric variables like height, gender and age, which will be suitable for Indian children.

Results

We calculated MIP and MEP of 320 (boys=160 and girls= 160) children in the age range of 7 years to 17 years of Mangaluru city, India. Results stated that mean MIP and MEP for boys were 72.5±32.8 cm H₂O and 73±33.2 cm H₂O, while for the girls it was 67±30.2 cm H₂O and 68±30.1 cm H₂O, respectively.

Conclusion

This study concluded that there is a difference in respiratory pressure values of Indian children with respect to those of other countries. Age, gender, height and BMI have a significant role in determining respiratory muscle strength. Boys demonstrated higher MIP and MEP. As age, height, weight and BMI increases, so does MIP and MEP.

The influence of the trunk muscle activation on occlusion pressure and respiratory muscle strength in healthy participants: Randomized controlled trial

OBJECTIVES

The purpose of the study was to check if the trunk muscle activation done in accordance with rules of the Bobath concept affects the occlusion pressure and respiratory muscle efficacy in forced breathing manoeuvres in healthy participants.

DESIGN

Randomized controlled trial. Between-subjects design.

PARTICIPANTS

Seventy-four healthy volunteers, aged 20-26 years, were recruited from medical students, randomly assigned to the experimental or control groups.

INTERVENTION

The intervention in the experimental group was individual physiotherapy based on the Bobath concept. It was provided by qualified physiotherapist and lasted about 60 min. The Bobath concept is an inclusive, individualized therapeutic approach to optimize movement recovery, informed by contemporary movement and neuro-sciences. The control group participated in a 45-minute lecture on the importance of the stability of trunk muscle and the diaphragm position that is adequate for its respiratory work. The described interventions, in both groups, were performed once, between the initial and final measurement of the respiratory drive.

OUTCOME MEASURES

The subjects underwent two assessments of the following variables: occlusion pressure (P0.1) and the respiratory muscle strength: maximal inspiratory pressure (PImax), maximal expiratory pressure (PEmax), maximal occlusion pressure (P0.1max) with the use of MasterScope Spirometer. In experimental group, the physiotherapy assessment was carried out before intervention.

RESULTS

As a result of the applied intervention, P0.1 in the experimental group increased (p = 0.001; 82.45 vs 103.73), which was not observed in the control group (p = 0.629; 88.95 vs 85.83). The intervention did not change the results of all other outcomes including P0.1 max; PImax and PEmax.

CONCLUSION

The activation of trunk muscles such as transversus abdominis, multifidius and muscles of the pelvic floor was found to improve the effectiveness of diaphragmatic work during tidal breathing as measured with P0.1 values. Established abdominal pressure, which stabilizes the trunk and prevents chest mobility, might be the reason why forced measurements (PImax, PEmax, P.01 max) remain unchanged.

Impact of respiratory physical therapy on heart rate autonomic control in children with leukemia

INTRODUCTION

Considering that heart rate (HR) autonomic control is impaired in cancer and subsequent respiratory effort may overload the heart, we aimed to evaluate the effect of a respiratory physical therapy session on HR autonomic regulation in children with leukemia so as to confirm its safety.

METHODS

We selected children with leukemia (n = 10) and healthy children (n = 11), which were submitted to a session of respiratory physical therapy. We used Spiron Kids (NCS, Brazil), Children's Voldyne (HUDSON RCI, USA), and Shaker (NCS, Brazil) as respiratory devices. The respiratory exercise protocols were founded on three standardized protocols. HR variability (HRV) was analyzed before, in the first minute and 5 to 10 min after intervention.

RESULTS

We recognized no change between rest and recovery from intervention in HRV (rMSSD-square root mean square of the differences between adjacent normal R-R intervals)-Control: p = 0.8111, Leukemia: p = 0.1197, among groups: p = 0.6574; SD1-standard deviation from instantaneous beat-to-beat variability-Control: p = 0.8111, Leukemia: p = 0.131, among groups: p = 0.6556; 0V-with no variation (3 equal symbols, for example (2,2,2)-Control: p = 0.3679, Leukemia: p = 0.3553, among groups: p = 0.7421); 2UV-with two variations to the contrary (the three symbols form a peak or a valley, for instance (3,5,3)-Control: p = 0.3679, Leukemia: p = 0.2359, among groups: p = 0.4007). HF-high frequency component, range 0.15 to 0.4 Hz-decreased 0 to 1 min after intervention in the leukemia group (p = 0.0303) and no change was observed in the control group between rest versus recovery from intervention (p = 0.9761). No significant change was reported in HF between groups (p = 0.8700). Two leukemia subjects treated with vincristine presented different HRV responses to the intervention group.

CONCLUSION

A respiratory physical therapy session did not significantly change autonomic control of HR in children with leukemia. Yet, clinicians should be mindful of subjects undergoing treatment with vincristine.