The Role of Diaphragmatic Rapid Shallow Breathing Index and Maximum Inspiratory Pressure in Predicting Outcome of Weaning From Mechanical Ventilation

Background Mechanical ventilation is the defining event of intensive care unit (ICU) management. It is a lifesaving intervention in patients with acute respiratory failure and whose spontaneous ventilation is inadequate for subsequent development of life threatening hypoxia and/or respiratory acidosis. Many physicians simply look at the patient’s ability to tolerate a spontaneous breathing trial (SBT) without distress through the respiratory rate (RR) and TV during the SBT. The RR/TV ratio, i.e., the rapid shallow breathing index (RSBI), one of the most used clinical indices to predict weaning outcome, reflects the balance between mechanical load posed on the inspiratory muscles and the inspiratory muscles ability to face it during the weaning attempt. However, RSBI was found to have both variable sensitivity and specificity for predicting weaning outcome. Although the diaphragm plays a fundamental role in generating TV in healthy subjects, if the diaphragmatic efficiency is impaired the accessory inspiratory muscles mild contribute to the ventilation for a limited period of time, for example during a SBT. However, since they are by far less efficient and more fatigable than the diaphragm, their exhaustion was likely lead to weaning failure in subsequent hours. Hence, the contribution of the accessory muscles to TV could compromise the diagnostic accuracy of the RSBI by masking the underlying diaphragmatic dysfunction. Aim of the Work To assess the accuracy of Diaphragmatic Rapid shallow breathing index and Maximum inspiratory pressure in predicting the outcome of weaning from mechanical ventilation. Patients and Methods The study was conducted at Ain Shams University Hospitals over 6 months on Patients who were mechanically ventilated for more than 48 hrs who were ready for weaning. Inclusion Criteria Patients intubated & mechanically ventilated for more than 48 hrs. Patients at their first SBT.Patients with adequate cough reflex. Patients fulfilling criteria of readiness for weaning from mechanical ventilation after resolution of cause of respiratory failure: Patients with score ranging between -1 and +1 on the Richmond Agitation and sedation scale (RASS). Exclusion criteria Age < 18 yrs. Patients with thoracotomy, pneumothorax, or pneumomediastinum. Patients with presence of flail chest or rib fractures. Patients with neuromuscular disease. Use of muscle-paralyzing agents within 48 hours before the study. History or new detection of paralysis or paradoxical movement of a single hemi diaphragm on diaphragmatic ultrasonography. Pregnant females. Unconscious noncooperative patients. Patients with intra-abdominal hypertension, Long term steroid therapy. Results I- Distribution of the studied patients regarding final outcome. II- Demographic data. III. Causes of MV. IV- Days on MV. V- Patients’ data and characteristics before start of weaning trial. VI- SBT Ventilator Breathing pattern after 30 min. VII- Study predictors. Conclusion D-RSBI is a new and promising tool that is superior to the traditional RSBI in predicting weaning outcome also MIP provides appreciated data with greater accuracy to assess inspiratory muscle strength and predicting weaning success in mechanically ventilated patients. Recommendations We could recommend the measurement of MIP and DRSBI as weaning predictors should be an integral part of evaluation of patients plan for weaning from MV. All intensivists should be acquitted with the use of U/S in the evaluation of diaphragmatic function.

Inspiratory Muscle Training Program Using the PowerBreath®: Does It Have Ergogenic Potential for Respiratory and/or Athletic Performance? A Systematic Review with Meta-Analysis

This systematic review and meta-analysis aim to provide scientific evidence regarding the effects of training on respiratory muscle training’s impact with the PowerBreath®. A systematic analysis based on the PRISMA guides and a conducted research structured around the bases of Web of Science, Scopus, Medline/PubMed, SciELO y Cochrane Library Plus. Six articles published before January 2021 were included. The documentation and quantification of heterogeneity in every meta-analysis were directed through Cochran’s Q test and the statistic I2; additionally, a biased publication analysis was made using funnel plots, whose asymmetry was quantified Egger’s regression. The methodological quality was assessed through McMaster’s. PowerBreath® administering a ≥ 15% resistive load of the maximum inspiratory pressure (PIM) achieves significant improvements (54%) in said pressure within 4 weeks of commencing the inspiratory muscle training. The maximal volume of oxygen (VO2max) considerable enhancements was achieved from the 6 weeks associated with the maximum inspiratory pressure ≥ 21.5% post inspiratory muscle training onwards. Conversely, a significant blood lactate concentration decrement occurred from the 4th week of inspiratory muscle training, after a maximum inspiratory pressure ≥ 6.8% increment. PowerBreath® is a useful device to stimulate sport performance and increase pulmonary function.

Increased body mass index: what is the influence on ventilatory muscular strength?

Introduction: Ventilatory muscle strength (VMS) and anatomical/biological factors are important in the functioning and maintenance of body homeostasis. Thus, the study of respiratory mechanics and conditions that can alter them is fundamental. Studies indicate that obesity decreases the Maximum Inspiratory Pressure (MIP) and Maximum Expiratory Pressure (MEP), however, these studies are contradictory in their results. Objective: To verify if there is a difference between the VMS of obese and eutrophic individuals. Methods: Comparative observational study, in which 40 individuals of both sexes were evaluated, divided into two groups: 20 individuals with grade I obesity and 20 eutrophic individuals. Abdominal circumference was considered to be > 102 cm for men and 88 cm for women. Two-way unpaired Student's t-test was applied to compare the Maximum Inspiratory Pressure (MIP) and Maximum Expiratory Pressure (MEP) of the evaluated groups. The BioEstat 5.0 program was used and a p ˂ 0.05 was adopted as significant. Results: The mean MIP for obese and eutrophic individuals was 147 ± 73 vs 145 ± 70 cmH2O, respectively (p = 0.91). For MEP, the mean for the obese and eutrophic group was 133 ± 28 vs 135 ± 27 cmH2O, respectively (p = 0.93). Conclusion: Sedentary individuals with grade I obesity associated with increased waist circumference do not differ in MIP and MEP when compared to eutrophic individuals.Keywords: obesity, work capacity assessment, functional physical performance.

Inter and Intra-rater Reliability and Validity of an instrument made in rural set up to measure Maximum Inspiratory Pressure termed as Dhiraj Maximum Inspiratory Pressure Device

Background: Maximum Inspiratory Pressure (MIP) measures inspiratory force generated by respiratory muscles. MIP is measured with non-invasive pressure transducer device which has mouthpiece, pressure gauge, and dial showing readings. Respiratory muscle weakness is a common sign depicted in conditions like neuromuscular disorders, cardiovascular disease, and other respiratory pathologies which affect the individual’s lung volume and capacity. The devices available in the market to measure the MIP are costly. Aim: This study was undertaken to find out inter-rater and intra-rater reliability and validity of therapist made instrument in rural set up to measure maximum inspiratory pressure (DMIPD). Method: This cross-sectional study was carried out in 40 normal healthy individuals without lung diseases were recruited as per inclusion criteria. MIP values were noted by two raters using the DMIPD and were then compared between two rater values to that of the gold standard values. Validity and reliability were calculated using interclass correlation coefficients (ICC) and p-value. Result: Statistical analysis for inter-rater reliability by Kappa using SPSS 1.000 showing almost perfect agreement as per Kappa interpretation also for intra-rater analysis an ICC value of 0.96 depicting excellent validity and Cronbach alpha value of 0.97 thereby proving it to have excellent reliability. Conclusion: We conclude that DMIPD has excellent reliability and validity.

Success or failure predictive indexes of extubation in renal transplants patients under mechanical ventilation – pilot study

Introduction: Currently, chronic kidney disease (CKD) is a major health problem and in the most severe conditions, kidney transplantation is an alternative treatment. However immunosuppression induced these patients to respiratory complications and endotracheal intubation. In order to assist the decision of the best time for weaning and extubation of these patients, there are predictive indexes that should be considered in preliminary assesment. Objective: To check the capacity of predictive indexes for weaning of mechanical ventilation, rapid shallow breathing index (RSBI), oxygenation rate (PaO2 /FiO2 ) and maximum inspiratory pressure (MIP) in predicting the success or extubation failure in kidney transplant patients. Methods: This study is a prospective cohort carried out with patients aged over 18, under mechanical ventilation for more than 24 hours. The patients were submitted to the Spontaneous Breathing Test, also the assessment of the Rapid Shallow Breathing Index, oxygenation index (PaO2 /FiO2 ), and maximum inspiratory pressure (MIP) and they were observed during 48 hours after to evaluate the success and extubation failure. Results: A total of 106 patients were eligible, and 20 of these were included with mean age of 46.9 ± 3.06 years and 14 of the subjects were male. Three patients showed extubation failure, and needed to have reintubation within the period of 48 hours as considered. Conclusion: The indices to predict weaning of mechanical ventilation, when within the expected normal values, seem to be able to predict extubation, with the exception of MIP that, even in cases of success, showed itself to be at levels lower than the predicted percentage.

The study of the effects of 12 weeks of yoga training on respiratory pressures and 40 mm Hg test in healthy individuals

Background: Yogic exercises have been found to be beneficial for better maintenance of bodily functions even in normal healthy subjects. In view of this, present study was planned to evaluate the effect of Yoga on respiratory pressures and 40 mm Hg test in healthy individuals. Method: The present study included 80 healthy subjects (40 males, 40 females) of 30-40 years age group. Subjects fulfilling the inclusion and exclusion criteria attended a minimum of five Yoga classes per week for a period of twelve weeks. Age, height, weight & BMI of the subjects were recorded. The maximum expiratory pressure, maximum inspiratory pressure and 40 mm Hg test were analysed before & after twelve weeks of Yoga practice. The same subjects were chosen as both study as well as control group in order to minimize the confounding factors and make the study more reproducible. Student’s paired‘t’ test was used to compare the changes in parameters before and after Yoga training. Results: On analysis of results, there was highly significant (p<0.001) increase in maximum expiratory pressure, maximum inspiratory pressure and 40 mm Hg test after twelve weeks of Yoga practise. The response was similar in both the genders. Conclusion: Present study proved that regular practice of Yoga for minimum of 12 weeks is beneficial in improving respiratory pressures and 40 mm Hg test in normal healthy individuals and this improvement is appreciable in both genders. Results of the study would justify the incorporation of Yoga as part of our lifestyle in promoting health. Also Yoga can make an appreciable contribution to primary prevention and management of lifestyle diseases.

The Effects of Inspiratory Muscle Training in Neuromuscular Disorders: Review Article

Introduction: Progressive inspiratory muscles weakness in neuromuscular disorders (NMD) can lead to respiratory impairments, from restrictive lung to respiratory failure. Inspiratory muscle training (IMT) is an exercise with a device to increase inspiratory muscles strength and/or endurance. This article was aimed to review the effect and prescription of IMT in NMD subjects. Methods: Searching method was done in PubMed and Google Scholar using keywords: “inspiratory muscle training” AND “neuromuscular disorders” AND “MIP” OR “PImax”. Results: Seven related studies were found. These studies shown that IMT increased inspiratory muscles strength and/or endurance in chronic progressive NMD. Most studies used threshold type. The intensities varied from 30% through 70% of maximum inspiratory pressure (MIP), minimum twice a day. The repetition for strengthening was 10 times with 20-seconds rest between repetitions. Endurance trainings were done in 10 cycles of 1-minute breathing or for total 20 m inutes. Conclusion: Several evidences reported that IMT significantly improve strength and endurance of inspiratory muscles in chronic progressive NMD. It was effective in earlier phase of NMD. The minimum load intensity was 30% MIP.

The Effects of Inspiratory Muscle Training in Neuromuscular Disorders: Review Article

Introduction: Progressive inspiratory muscles weakness in neuromuscular disorders (NMD) can lead to respiratory impairments, from restrictive lung to respiratory failure. Inspiratory muscle training (IMT) is an exercise with a device to increase inspiratory muscles strength and/or endurance. This article wasaimed to review the effect and prescription of IMT in NMD subjects.Methods: Searching method was done in PubMed and Google Scholar using keywords: “inspiratory muscle training” AND “neuromuscular disorders” AND “MIP” OR “PImax”.Results: Seven related studies were found. These studies shown that IMT increased inspiratory muscles strength and/or endurance in chronic progressive NMD. Most studies used threshold type. The intensities varied from 30% through 70% of maximum inspiratory pressure (MIP), minimum twice a day. Therepetition for strengthening was 10 times with 20-seconds rest between repetitions. Endurance trainings were done in 10 cycles of 1-minute breathing or for total 20 m inutes.Conclusion: Several evidences reported that IMT significantly improve strength and endurance of inspiratory muscles in chronic progressive NMD. It was effective in earlier phase of NMD. The minimum load intensity was 30% MIP.Keywords: Inspiratory muscle training (IMT), neuromuscular disorders (NMD), maximum inspiratory pressure (MIP)