Inspiratory muscle training did not accelerate weaning from mechanical ventilation but did improve tidal volume and maximal respiratory pressures: a randomised trial

Assessing the efficacy of a graded pulmonary rehabilitation protocol in mechanically ventilated patients following brainstem hemorrhage

BACKGROUND

The objective of this study is to assess the impact of an early-graded pulmonary rehabilitation training program on patients undergoing mechanical ventilation due to brainstem hemorrhage.

METHODS

Eighty patients receiving mechanical ventilation due to brainstem hemorrhage at our hospital's neurosurgery department between August 2022 and October 2023 were enrolled as participants. A sampling table was generated based on the order of admission, and 80 random sequences were generated using SPSS software. These sequences were then sorted in ascending order, with the first half designated as the control group and the second half as the intervention group, each comprising 40 cases. The control group received standard nursing care for mechanical ventilation in brainstem hemorrhage cases, while the intervention group underwent early-graded pulmonary rehabilitation training in addition to standard care. This intervention was conducted in collaboration with a multidisciplinary respiratory critical care rehabilitation team. The study compared respiratory function indices, ventilator weaning success rates, ventilator-associated pneumonia incidence, mechanical ventilation duration, and patient discharge duration between the 2 groups.

RESULTS

The comparison between patients in the observation group and the control group regarding peak expiratory flow and maximum inspiratory pressure on days 1, 3, 5, and 7 revealed statistically significant differences (P < .05). Additionally, there was a statistically significant interaction between the main effect of intervention and the main effect of time (P < .05). The success rate of ventilator withdrawal was notably higher in the observation group (62.5%) compared to the control group (32.5%), with a statistically significant difference (P < .05). Moreover, the incidence rate of ventilator-associated pneumonia was significantly lower in the observation group (2.5%) compared to the control group (17.5%) (P < .05). Furthermore, both the duration of mechanical ventilation and hospitalization were significantly shorter in the observation group compared to the control group (P < .05).

CONCLUSION

Early-graded pulmonary rehabilitation training demonstrates effectiveness in enhancing respiratory function, augmenting the ventilator withdrawal success rate, and reducing both the duration of mechanical ventilation and hospitalization in mechanically ventilated patients with brainstem hemorrhage. These findings suggest the potential value of promoting the application of this intervention in clinical practice.

Low-Medium and High-Intensity Inspiratory Muscle Training in Critically Ill Patients: A Systematic Review and Meta-Analysis

Background and objectives: Mechanical ventilation is often used in intensive care units to assist patients' breathing. This often leads to respiratory muscle weakness and diaphragmatic dysfunction, causing weaning difficulties. Inspiratory muscle training (IMT) has been found to be beneficial in increasing inspiratory muscle strength and facilitating weaning. Over the years, different protocols and devices have been used. Materials and Methods: The aim of this systematic review and meta-analysis was to investigate the effectiveness of low-medium (LM-IMT) and high-intensity (H-IMT) threshold inspiratory muscle training in critically ill patients. A systematic literature search was performed for randomized controlled trials (RCTs) in the electronic databases Google Scholar, PubMed, Scopus, and Science Direct. The search involved screening for studies examining the effectiveness of two different intensities of threshold IMT in critically ill patients published the last 10 years. The Physiotherapy Evidence Database (PEDro) scale was chosen as the tool to assess the quality of studies. A meta-analysis was performed where possible. Results: Fourteen studies were included in the systematic review, with five of them having high methodological quality. Conclusions: When examining LM-IMT and H-IMT though, neither was able to reach statistically significant improvement in their maximal inspiratory pressure (MIP), while LM-IMT reached it in terms of weaning duration. Additionally, no statistical difference was noticed in the duration of mechanical ventilation. The application of IMT is recommended to ICU patients in order to prevent diaphragmatic dysfunction and facilitate weaning from mechanical ventilation. Therefore, further research as well as additional RCTs regarding different protocols are needed to enhance its effectiveness.

Managing respiratory muscle weakness during weaning from invasive ventilation

Weaning is a critical stage of an intensive care unit (ICU) stay, in which the respiratory muscles play a major role. Weakness of the respiratory muscles, which is associated with significant morbidity in the ICU, is not limited to atrophy and subsequent dysfunction of the diaphragm; the extradiaphragmatic inspiratory and expiratory muscles also play important parts. In addition to the well-established deleterious effect of mechanical ventilation on the respiratory muscles, other risk factors such as sepsis may be involved. Weakness of the respiratory muscles can be suspected visually in a patient with paradoxical movement of the abdominal compartment. Measurement of maximal inspiratory pressure is the simplest way to assess respiratory muscle function, but it does not specifically take the diaphragm into account. A cut-off value of -30 cmH₂O could identify patients at risk for prolonged ventilatory weaning; however, ultrasound may be better for assessing respiratory muscle function in the ICU. Although diaphragm dysfunction has been associated with weaning failure, this diagnosis should not discourage clinicians from performing spontaneous breathing trials and considering extubation. Recent therapeutic developments aimed at preserving or restoring respiratory muscle function are promising.

The effect of threshold inspiratory muscle training on the duration of weaning in intensive care unit-admitted patients: A randomized clinical trial

Background

The purpose of this study was to evaluate the effect of threshold inspiratory muscle training (IMT) on the duration of weaning in intensive care unit (ICU)-admitted patients.

Materials and Methods

This randomized clinical trial enrolled 79 ICU-admitted, mechanically ventilated patients in 2020-2021 in Imam Reza Hospital, Mashhad. Patients were randomly divided into intervention (n = 40) and control (n = 39) groups. The intervention group received threshold IMT and conventional chest physiotherapy, while the control group only received conventional chest physiotherapy once a day. Before and after the end of the intervention, the strength of inspiratory muscles and the duration of weaning were measured in both the groups.

Results

The duration of weaning was shorter in the intervention group (8.4 ± 1.1 days) versus the control group (11.2 ± 0.6 days) (P < 0.001). The rapid shallow breathing index decreased by 46.5% in the intervention group and by 27.3% in the control group after the intervention (both P < 0.001), and the between-group comparison showed a significantly higher reduction in the intervention group than control group (P < 0.001). The patients' compliance after the intervention compared to the 1^st day increased to 16.2 ± 6.6 in the intervention group and 9.6 ± 6.8 in the control group (both P < 0.001), and the between-group comparison showed a significantly higher increase in the intervention group than control group. The maximum inspiratory pressure increased by 13.7 ± 6.1 in the intervention group and by 9.1 ± 6.0 in the control group (P < 0.001). Furthermore, the weaning success was 54% more probable in the intervention group than control group (P < 0.05).

Conclusion

The results of this study showed the positive effect of IMT with threshold IMT trainer on increased strength of respiratory muscles and reduced weaning duration.

Does Wim Hof Method Improve Breathing Economy during Exercise?

(1) Background: Breathing economy during endurance sports plays a major role in performance. Poor breathing economy is mainly characterized by excessive breathing frequency (BF) and low tidal volume (VT) due to shallow breathing. The purpose of this study was to evaluate whether a 4 week intervention based on the Wim Hof breathing method (WHBM) would improve breathing economy during exercise in adolescent runners. (2) Methods: 19 adolescent (16.6 ± 1.53 years) middle- and long-distance runners (11 boys and 8 girls) participated in the study. Participants were randomly divided into experimental (n = 11) and control groups (n = 8). The study was set in the transition period between competitive race seasons and both groups had a similar training program in terms of running volume and intensity over the course of the study. The experimental group performed breathing exercises every day (~20 min/day) for 4 weeks. The control group did not perform any kind of breathing exercise. The breathing exercises consisted of three sets of controlled hyperventilation and consecutive maximum breath holds. Before and after the intervention, participants performed incremental cycle ergometer testing sessions consisting of two minute stages at 1, 2, 3, and 4 W·kg−1 with breath-by-breath metabolic analysis. During the testing sessions, BF, VT, and minute ventilation (VE) were assessed and compared. (3) Results: There were no statistically significant differences (p > 0.05) in BF, VT, or VE between experimental and control groups before or after the intervention. A nonsignificant small-to-large effect for an increase in VE and BF in both groups following the 4 week intervention period was observed, possibly due to a reduction in training volume and intensity owing to the down period between competitive seasons. (4) Conclusions: The 4 week intervention of WHBM did not appear to alter parameters of breathing economy during a maximal graded exercise test in adolescent runners.

Impact of Inspiratory Muscle Training on Weaning Parameters in Prolonged Ventilator-Dependent Patients: A Preliminary Study

Introduction

Patients require prolonged mechanical ventilation to overcome respiratory failure in the chronic respiratory care ward; however, how to facilitate ventilator weaning using a nurse-led strategy is limited.

Objectives

This study aimed to examine the impact of adjusting ventilator trigger sensitivity as inspiratory muscle training on weaning parameters in patients with prolonged ventilator dependence.

Methods

Multiple pre-test–post-test with a non-equivalent control group design was conducted at a chronic respiratory care ward in southern Taiwan. A convenience sampling method was used to recruit patients who received prolonged mechanical ventilation for more than 21 days into control (n  =  20) and intervention groups (n  =  22). Adjustment of ventilator trigger sensitivity started from 10% of the initial maximum inspiratory pressure and increased to 40% after a training period of six weeks. The weaning parameters were collected for pre-test and multiple post-tests, and statistical analysis of treatment effects was performed using the generalized estimating equation.

Results

Magnitude of weaning parameters was significantly higher in the intervention group after the six-week training, including maximum inspiratory pressure, rapid shallow breathing index, tidal volume, and ratio of arterial-to-inspired oxygen.

Conclusion

Adjustment of ventilator trigger sensitivity as inspiratory muscle training can help prolonged ventilator-dependent patients improve their respiratory muscle strength, breathing patterns, and oxygenation.

A randomized controlled trial to determine whether beta-hydroxy-beta-methylbutyrate and/or eicosapentaenoic acid improves diaphragm and quadriceps strength in critically Ill mechanically ventilated patients

Background

Intensive care unit acquired weakness is a serious problem, contributing to respiratory failure and reductions in ambulation. Currently, there is no pharmacological therapy for this condition. Studies indicate, however, that both beta-hydroxy-beta-methylbutyrate (HMB) and eicosapentaenoic acid (EPA) increase muscle function in patients with cancer and in older adults. The purpose of this study was to determine whether HMB and/or EPA administration would increase diaphragm and quadriceps strength in mechanically ventilated patients.

Methods

Studies were performed on 83 mechanically ventilated patients who were recruited from the Medical Intensive Care Units at the University of Kentucky. Diaphragm strength was assessed as the trans-diaphragmatic pressure generated by supramaximal magnetic phrenic nerve stimulation (PdiTw). Quadriceps strength was assessed as leg force generated by supramaximal magnetic femoral nerve stimulation (QuadTw). Diaphragm and quadriceps thickness were assessed by ultrasound. Baseline measurements of muscle strength and size were performed, and patients were then randomized to one of four treatment groups (placebo, HMB 3 gm/day, EPA 2 gm/day and HMB plus EPA). Strength and size measurements were repeated 11 days after study entry. ANCOVA statistical testing was used to compare variables across the four experimental groups.

Results

Treatments failed to increase the strength and thickness of either the diaphragm or quadriceps when compared to placebo. In addition, treatments also failed to decrease the duration of mechanical ventilation after study entry.

Conclusions

These results indicate that a 10-day course of HMB and/or EPA does not improve skeletal muscle strength in critically ill mechanically ventilated patients. These findings also confirm previous reports that diaphragm and leg strength in these patients are profoundly low. Additional studies will be needed to examine the effects of other anabolic agents and innovative forms of physical therapy.

Trial registration: ClinicalTrials.gov, NCT01270516. Registered 5 January 2011, https://clinicaltrials.gov/ct2/show/NCT01270516?term=Supinski&draw=2&rank=4.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03737-9.

Transcutaneous electrical diaphragmatic stimulation reduces the duration of invasive mechanical ventilation in patients with cervical spinal cord injury: retrospective case series

Study design

Retrospective case series.

Objectives

To compare individuals with cervical spinal cord injury (SCI) submitted to transcutaneous electrical diaphragmatic stimulation (TEDS) or a standard weaning protocol (SWP) according to the following variables: invasive mechanical ventilation (IMV) time, ventilator weaning time, intensive care unit (ICU) length of stay, and overall hospital length of stay.

Settings

Tertiary university hospital. Clinical Hospital of Campinas State University—UNICAMP—Campinas (SP), Brazil.

Methods

Retrospective case study investigating ICU patients submitted to tracheostomy due to cervical SCI at a tertiary university hospital (Clinical Hospital of Campinas State University, Brazil). Data were extracted from medical records of patients seen between January 2007 and December 2016. According to medical records, four patients were submitted to TEDS and six to a SWP. Provision of training to patients in the TEDS group was based on consensus medical decision, preference of the physical therapy team and availability of electrostimulation equipment in the ICU.

Results

Total IMV time in the TEDS and the SWP group was 33 ± 15 and 60 ± 22 days, respectively. Length of stay in ICU in the TEDS and the SWP group was 31 ± 18 and 63 ± 45 days, respectively.

Conclusion

TEDS appears to influence the duration of IMV as well as the length of stay in ICU. This physiotherapeutic intervention may be a potentially promising tool for treatment of patients with SCI. However, randomized clinical trials are warranted to support this assumption.

Effectiveness of Pre-operative Respiratory Muscle Training versus Conventional Treatment for Improving Post operative Pulmonary Health after Coronary Artery Bypass Grafting

Objective:

To evaluate the Effectiveness of Pre-operative Respiratory Muscle Training versus Conventional Treatment for Improving post-operative pulmonary health after Coronary Artery Bypass Graft Surgery (CABG).

Methods:

A Prospective Randomized clinical trial was performed on sixty patients who underwent elective CABG at Faisalabad Institute of Cardiology. At the time of admission all patients were subjected to 6-minutes’ walk test (6MWT) as baseline. The subjects were then divided into two groups. The Group-I was subjected to respiratory muscle training whereas the Group-2 received the routine preoperative care. The 6-minute walk test (6MWT) was then repeated a day before surgery (pre-operative) and before discharge (post-operatively). Duration of post-operative mechanical ventilation, oxygen therapy and hospital stay were also noted as outcome measures of this study.

Results:

The pre-operative and post-operative readings showed that the patients in the interventional group performed better than the control group in their 6MWT with P-value of less than 0.05. Similarly the interventional group had shorter duration of mechanical ventilation, dependence on oxygen therapy and postoperative hospital stay as compared with the control group showing P-values below 0.05.

Conclusion:

The results showed that respiratory muscle training results in improved postoperative functional capacity and reduces of hospital stay.

Effects of Inspiratory Muscle Training and Early Mobilization on Weaning of Mechanical Ventilation: A Systematic Review and Network Meta-analysis

OBJECTIVE

To compare the effectiveness and rank order of physical therapy interventions, including conventional physical therapy (CPT), inspiratory muscle training (IMT), and early mobilization (EM) on mechanical ventilation (MV) duration and weaning duration.

DATA SOURCES

PubMed, The Cochrane Library, Scopus, and CINAHL complete electronic databases were searched through August 2019.

STUDY SELECTION

Randomized controlled trials (RCTs) investigating the effect of IMT, EM, or CPT on MV duration and the weaning duration in patients with MV were included. Studies that were determined to meet the eligibility criteria by 2 independent authors were included. A total of 6498 relevant studies were identified in the search, and 18 RCTs (934 participants) were included in the final analysis.

DATA EXTRACTION

Data were extracted independently by 2 authors and assessed the study quality by the Cochrane risk-of-bias tool. The primary outcomes were MV duration and weaning duration.

DATA SYNTHESIS

Various interventions of physical therapy were identified in the eligible studies, including IMT, IMT+CPT, EM, EM+CPT, and CPT. The data analysis demonstrated that compared with CPT, IMT+CPT significantly reduced the weaning duration (mean difference; 95% confidence interval) (-2.60; -4.76 to -0.45) and EM significantly reduced the MV duration (-2.01; -3.81 to -0.22). IMT+CPT and EM had the highest effectiveness in reducing the weaning duration and MV duration, respectively.

CONCLUSION

IMT or EM should be recommended for improving the weaning outcomes in mechanically ventilated patients. However, an interpretation with caution is required due to the heterogeneity.

Inhibition of central activation of the diaphragm: a mechanism of weaning failure

During a T-tube trial following disconnection of mechanical ventilation, patients failing the trial do not develop contractile diaphragmatic fatigue despite increases in inspiratory pressure output. Studies in volunteers, patients, and animals raise the possibility of spinal and supraspinal reflex mechanisms that inhibit central-neural output under loaded conditions. We hypothesized that diaphragmatic recruitment is submaximal at the end of a failed weaning trial despite concurrent respiratory distress. Tidal transdiaphragmatic pressure (ΔP_di) and electrical activity (ΔEA_di) were recorded with esophago-gastric catheters during a T-tube trial in 20 critically ill patients. During the T-tube trial, ∆EA_di was greater in weaning failure patients than in weaning success patients (P = 0.049). Despite increases in ΔP_di, from 18.1 ± 2.5 to 25.9 ± 3.7 cm H₂O (P < 0.001), rate of transdiaphragmatic pressure development (from 22.6 ± 3.1 to 37.8 ± 6.7 cm H₂O/s; P < 0.0004), and concurrent respiratory distress, ∆EA_di at the end of a failed T-tube trial was half of maximum, signifying inhibition of central neural output to the diaphragm. The increase in ΔP_di in the weaning failure group, while ∆EA_di remained constant, indicates unexpected improvement in diaphragmatic neuromuscular coupling (from 46.7 ± 6.5 to 57.8 ± 8.4 cm H₂O/%; P = 0.006). Redistribution of neural output to the respiratory muscles characterized by a progressive increase in rib cage and accessory muscle contribution to tidal breathing and expiratory muscle recruitment contributed to enhanced coupling. In conclusion, diaphragmatic recruitment is submaximal at the end of a failed weaning trial despite concurrent respiratory distress. This finding signifies that reflex inhibition of central neural output to the diaphragm contributes to weaning failure.

NEW & NOTEWORTHY Research into pathophysiology of failure to wean from mechanical ventilation has excluded several factors, including contractile fatigue, but the precise mechanism remains unknown. We recorded transdiaphragmatic pressure and diaphragmatic electrical activity in patients undergoing a T-tube trial. Diaphragmatic recruitment was submaximal at the end of a failed trial despite concurrent respiratory distress, signifying that inhibition of central neural output to the diaphragm is an important mechanism of weaning failure.

Cambios fisiológicos relacionados con entrenamiento muscular respiratorio en pacientes con ventilación mecánica

Introducción. El entrenamiento muscular respiratorio es una técnica fisioterapéutica usada para incrementar la fuerza de la musculatura respiratoria, sin embargo pocos estudios han abordado los cambios fisiológicos relacionados con esta intervención en pacientes con ventilación mecánica.Objetivo. Determinar los cambios fisiológicos relacionados con el entrenamiento muscular respiratorio en pacientes con ventilación mecánica.Materiales y métodos. Se realizó un análisis de datos secundarios en el marco del estudio “Eficacia del entrenamiento muscular respiratorio en el destete de la ventilación mecánica en pacientes con ventilación mecánica por 48 horas o más: Un ensayo clínico controlado”. La población estuvo conformada por los 62 pacientes del grupo experimental del estudio principal, quienes recibieron entrenamiento muscular respiratorio. Los valores de frecuencia cardiaca, frecuencia respiratoria, presión arterial, saturación de oxígeno y volumen corriente fueron registrados. La diferencia entre el promedio de cada una de las variables fue analizada mediante la prueba de t pareada, mientras que para el análisis de los cambios fisiológicos entre sesiones de entrenamiento se empleó la prueba de Kruskal-Wallis.Resultados. Se observaron diferencias significativas entre las variables fisiológicas antes y después del entrenamiento muscular respiratorio (p<0.05), a excepción del volumen corriente y la presión arterial media (p>0.05). Por el contrario, no se observaron diferencias significativas en ninguna de las variables fisiológicas entre sesiones de entrenamiento (p>0.05)Conclusiones. El entrenamiento muscular respiratorio es una intervención terapéutica viable y tolerable en esta población.

Respiratory Muscle Rehabilitation in Patients with Prolonged Mechanical Ventilation: A Targeted Approach

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2020. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2020. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.

Inspiratory Muscle Rehabilitation in Critically Ill Adults. A Systematic Review and Meta-Analysis

RATIONALE

Respiratory muscle weakness is common in critically ill patients; the role of targeted inspiratory muscle training (IMT) in intensive care unit rehabilitation strategies remains poorly defined.

OBJECTIVES

The primary objective of the present study was to describe the range and tolerability of published methods for IMT. The secondary objectives were to determine whether IMT improves respiratory muscle strength and clinical outcomes in critically ill patients.

METHODS

We conducted a systematic review to identify randomized and nonrandomized studies of physical rehabilitation interventions intended to strengthen the respiratory muscles in critically ill adults. We searched the MEDLINE, Embase, HealthSTAR, CINAHL, and CENTRAL databases (inception to September Week 3, 2017) and conference proceedings (2012 to 2017). Data were independently extracted by two authors and collected on a standardized report form.

RESULTS

A total of 28 studies (N = 1,185 patients) were included. IMT was initiated during early mechanical ventilation (8 studies), after patients proved difficult to wean (14 studies), or after extubation (3 studies), and 3 other studies did not report exact timing. Threshold loading was the most common technique; 13 studies employed strength training regimens, 11 studies employed endurance training regimens, and 4 could not be classified. IMT was feasible, and there were few adverse events during IMT sessions (nine studies; median, 0%; interquartile range, 0-0%). In randomized trials (n = 20), IMT improved maximal inspiratory pressure compared with control (15 trials; mean increase, 6 cm H₂O; 95% confidence interval [CI], 5-8 cm H₂O; pooled relative ratio of means, 1.19; 95% CI, 1.14-1.25) and maximal expiratory pressure (4 trials; mean increase, 9 cm H₂O; 95% CI, 5-14 cm H₂O). IMT was associated with a shorter duration of ventilation (nine trials; mean difference, 4.1 d; 95% CI, 0.8-7.4 d) and a shorter duration of weaning (eight trials; mean difference, 2.3 d; 95% CI, 0.7-4.0 d), but confidence in these pooled estimates was low owing to methodological limitations, including substantial statistical and methodological heterogeneity.

CONCLUSIONS

Most studies of IMT in critically ill patients have employed inspiratory threshold loading. IMT is feasible and well tolerated in critically ill patients and improves both inspiratory and expiratory muscle strength. The impact of IMT on clinical outcomes requires future confirmation.

Ventilator-induced diaphragm dysfunction: translational mechanisms lead to therapeutical alternatives in the critically ill

Mechanical ventilation [MV] is a life-saving technique delivered to critically ill patients incapable of adequately ventilating and/or oxygenating due to respiratory or other disease processes. This necessarily invasive support however could potentially result in important iatrogenic complications. Even brief periods of MV may result in diaphragm weakness [i.e., ventilator-induced diaphragm dysfunction [VIDD]], which may be associated with difficulty weaning from the ventilator as well as mortality. This suggests that VIDD could potentially have a major impact on clinical practice through worse clinical outcomes and healthcare resource use. Recent translational investigations have identified that VIDD is mainly characterized by alterations resulting in a major decline of diaphragmatic contractile force together with atrophy of diaphragm muscle fibers. However, the signaling mechanisms responsible for VIDD have not been fully established. In this paper, we summarize the current understanding of the pathophysiological pathways underlying VIDD and highlight the diagnostic approach, as well as novel and experimental therapeutic options.

Expiratory muscle dysfunction in critically ill patients: towards improved understanding

Introduction

This narrative review summarizes current knowledge on the physiology and pathophysiology of expiratory muscle function in ICU patients, as shared by academic professionals from multidisciplinary, multinational backgrounds, who include clinicians, clinical physiologists and basic physiologists.

Results

The expiratory muscles, which include the abdominal wall muscles and some of the rib cage muscles, are an important component of the respiratory muscle pump and are recruited in the presence of high respiratory load or low inspiratory muscle capacity. Recruitment of the expiratory muscles may have beneficial effects, including reduction in end-expiratory lung volume, reduction in transpulmonary pressure and increased inspiratory muscle capacity. However, severe weakness of the expiratory muscles may develop in ICU patients and is associated with worse outcomes, including difficult ventilator weaning and impaired airway clearance. Several techniques are available to assess expiratory muscle function in the critically ill patient, including gastric pressure and ultrasound.

Conclusion

The expiratory muscles are the "neglected component" of the respiratory muscle pump. Expiratory muscles are frequently recruited in critically ill ventilated patients, but a fundamental understanding of expiratory muscle function is still lacking in these patients.

Temporary transvenous diaphragm pacing vs. standard of care for weaning from mechanical ventilation: study protocol for a randomized trial

BACKGROUND

Mechanical ventilation (MV) is a life-saving technology that restores or assists breathing. Like any treatment, MV has side effects. In some patients it can cause diaphragmatic atrophy, injury, and dysfunction (ventilator-induced diaphragmatic dysfunction, VIDD). Accumulating evidence suggests that VIDD makes weaning from MV difficult, which involves increased morbidity and mortality.

METHODS AND ANALYSIS

This paper describes the protocol of a randomized, controlled, open-label, multicenter trial that is designed to investigate the safety and effectiveness of a novel therapy, temporary transvenous diaphragm pacing (TTVDP), to improve weaning from MV in up to 88 mechanically ventilated adult patients who have failed at least two spontaneous breathing trials over at least 7 days. Patients will be randomized (1:1) to TTVDP (treatment) or standard of care (control) groups. The primary efficacy endpoint is time to successful extubation with no reintubation within 48 h. Secondary endpoints include maximal inspiratory pressure and ultrasound-measured changes in diaphragm thickness and diaphragm thickening fraction over time. In addition, observational data will be collected and analyzed, including 30-day mortality and time to discharge from the intensive care unit and from the hospital. The hypothesis to be tested postulates that more TTVDP patients than control patients will be successfully weaned from MV within the 30 days following randomization.

DISCUSSION

This study is the first large-scale clinical trial of a novel technology (TTVDP) aimed at accelerating difficult weaning from MV. The technology tested provides the first therapy directed specifically at VIDD, an important cause of delayed weaning from MV. Its results will help delineate the place of this therapeutic approach in clinical practice and help design future studies aimed at defining the indications and benefits of TTVDP.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03096639 . Registered on 30 March 2017.

Chest physiotherapy with early mobilization may improve extubation outcome in critically ill patients in the intensive care units

BACKGROUND

Extubation failure can lead to a longer intensive care unit (ICU) stay, higher mortality rate, and higher risk of requiring tracheostomy. Chest physiotherapy (CPT) can help patients in reducing the accumulation of airway secretion, preventing collapsed lung, improving lung compliance, and reducing comorbidities. Much research has investigated the correlation between CPT and respiratory system clearance. However, few studies have investigated the correlation between CPT and failed ventilator extubation. Therefore, this study aimed to investigate the use of CPT for reducing the rate of failed removal from mechanical ventilators.

METHODS

This study was an intervention study with mechanical control. Subjects were divided into two groups. The control group, which received routine nursing chest care, was selected from a retrospective chart review. The intervention group was prospectively taken into the chest physiotherapy program. The chest physiotherapy treatment protocol consisted of inspiratory muscle training, manual hyperinflation, chest wall mobilization, secretion removal, cough function training, and early mobilization.

RESULTS

A total of 439 subjects were enrolled in the intervention and control groups, with a mean age of 69 years. APACHE II score (P = .09) and GCS scores (P = .54) were similar between the two groups. Compared to the control group, patients in the intervention group had a significantly lower reintubation rate (8% vs 16%; P = .01).

CONCLUSIONS

The results indicate that intensive chest physiotherapy could decrease extubation failure in mechanically ventilated patients in the ICU. In addition, chest physiotherapy could also significantly improve the rapid shallow breathing index score.

Análise da força muscular expiratória e respiração espontânea de indivíduos em ventilação mecânica: estudo transversal

RESUMO Os músculos da expiração têm funções em todo o ciclo respiratório, mas não são frequentemente avaliados no desmame da ventilação mecânica. Assim, revisões e consensos não mencionam a pressão expiratória máxima (PEmáx) e o treino expiratório. Objetivou-se investigar a relação da força muscular expiratória com a respiração espontânea de indivíduos ventilados mecanicamente. Trata-se de um estudo transversal com participantes de 18 a 79 anos de idade. Foram formados os grupos PEmáx satisfatória (GPES) e PEmáx baixa (GPEB) conforme o ponto de corte de 55cmH2O e comparados a parâmetros de desmame. O GPES (n=9) teve desempenho superior ao do GPEB (n=21) no índice de respiração rápida e superficial (IRRS) (40,6±17,6rpm/L e 75,3±44,1rpm/L, respectivamente; p=0,022) e na frequência respiratória (f) (19,1±6,2rpm e 26,1±9,4rpm; p=0,044). A prevalência de PEmáx satisfatória foi pequena, observada no tamanho dos grupos. Além disso, embora a PEmáx percentual do valor predito tenha sido menor no GPEB, como esperado (67,2±15,4% vs. 45,8±14,7%; p=0,001), a pressão inspiratória máxima percentual não diferiu significantemente (82,4±21,8% vs. 67,8±18,4%; p=0,077). A PEmáx se correlacionou moderadamente com o IRRS (r=-0,406; p=0,026) e com a f (r=-0,426; p=0,017). Conclui-se que a PEmáx≥55cmH2O esteve associada à melhores valores no IRRS e na f, e que a redução da força muscular expiratória foi mais prevalente e severa que a da força muscular inspiratória.

Efficacy of respiratory muscle training in weaning of mechanical ventilation in patients with mechanical ventilation for 48hours or more: A Randomized Controlled Clinical Trial

OBJECTIVE

To evaluate the efficacy of respiratory muscular training in the weaning of mechanical ventilation and respiratory muscle strength in patients on mechanical ventilation of 48hours or more.

DESIGN

Randomized controlled trial of parallel groups, double-blind. Ambit: Intensive Care Unit of a IV level clinic in the city of Cali.

PATIENTS

126 patients in mechanical ventilation for 48hours or more.

INTERVENTIONS

The experimental group received daily a respiratory muscle training program with treshold, adjusted to 50% of maximal inspiratory pressure, additional to standard care, conventional received standard care of respiratory physiotherapy. MAIN INTEREST VARIABLES: weaning of mechanical ventilation. Other variables evaluated: respiratory muscle strength, requirement of non-invasive mechanical ventilation and frequency of reintubation.

ANALYSIS

intention-to-treat analysis was performed with all variables evaluated and analysis stratified by sepsis condition.

RESULTS

There were no statistically significant differences in the median weaning time of the MV between the groups or in the probability of extubation between groups (HR: 0.82 95% CI: 0.55-1.20 P=.29). The maximum inspiratory pressure was increased in the experimental group on average 9.43 (17.48) cmsH20 and in the conventional 5.92 (11.90) cmsH20 (P=.48). The difference between the means of change in maximal inspiratory pressure was 0.46 (P=.83 95%CI -3.85 to -4.78).

CONCLUSIONS

respiratory muscle training did not demonstrate efficacy in the reduction of the weaning period of mechanical ventilation nor in the increase of respiratory muscle strength in the study population. Registered study at ClinicalTrials.gov (NCT02469064).

Safety and efficacy of inspiratory muscle training for preventing adverse outcomes in patients at risk of prolonged hospitalisation

Background

The early institution of inspiratory muscle training on hospitalised patients with no established respiratory deficits could prevent in-hospital adverse outcomes that are directly or indirectly associated to the loss of respiratory muscle mass inherent to a prolonged hospital stay. The objective of the clinical trial is to assess the impact of inspiratory muscle training on hospital inpatient complications.

Methods

This is a double-blind randomised controlled trial. Subjects in the intervention group underwent an inspiratory muscle training loaded with 50% maximum inspiratory pressure twice daily for 4 weeks from study enrolment. Patients were randomly assigned to an inspiratory muscle training group or a sham inspiratory muscle training group. All patients received conventional physiotherapy interventions. Baseline and post-intervention respiratory and peripheral muscle strength, functionality (performance of activities of daily living), length of hospital stay, and death were evaluated. Clinical outcomes were assessed until hospital discharge. This study was approved by the Institutional Hospital Ethics Committee (03/2014).

Results

Thirty-one patients assigned to the inspiratory muscle training group and 34 to the sham inspiratory muscle training group were analysed. Patients in the inspiratory muscle training group had a shorter mean length of hospital stay (35.3 ± 2.7 vs. 41.8 ± 3.5 days, p < 0.01) and a lower risk of endotracheal intubation (relative risk (RR) = 0.36; 95% confidence interval (CI) 0.27–0.97; p = 0.03) as well as muscle weakness (RR = 0.36; 95% CI 0.19–0.98; p = 0.02) and mortality (RR = 0.23; 95% CI 0.2–0.94; p = 0.04). The risk of adverse events did not differ significantly between groups.

Conclusion

Inspiratory muscle training was a protective factor against endotracheal intubation, muscle weakness, and mortality.

Trial registration

ClinicalTrials.gov, ID: NCT02459444. Registered on 19 May 2015.

Inspiratory Muscle Training in the Intensive Care Unit: A New Perspective

Background

Prolonged use of mechanical ventilation (MV) leads to weakening of the respiratory muscles, especially in patients subjected to sedation, but this effect seems to be preventable or more quickly reversible using respiratory muscle training. The aims of the study were to assess variations in respiratory and hemodinamic parameters with electronic inspiratory muscle training (EIMT) in tracheostomized patients requiring MV and to compare these variations with those in a group of patients subjected to an intermittent nebulization program (INP).

Methods

This was a pilot, prospective, randomized study of tracheostomized patients requiring MV in one intensive care unit (ICU). Twenty-one patients were randomized: 11 into the INP group and 10 into the EIMT group. Two patients were excluded in experimental group because of hemodynamic instability.

Results

In the EIMT group, maximal inspiratory pressure (MIP) after training was significantly higher than that before (P = 0.017), there were no hemodynamic changes, and the total weaning time was shorter than in the INP group (P = 0.0192).

Conclusion

The EIMT device is safe, promotes an increase in MIP, and leads to a shorter ventilator weaning time than that seen in patients treated using INP.

Physiotherapy management of intensive care unit-acquired weakness

[Hodgson CL, Tipping CJ (2016) Physiotherapy management of intensive care unit-acquired weakness.Journal of Physiotherapy63: 4-10].

Use of Powerbreathe® in inspiratory muscle training for athletes: systematic review

Abstract Introduction: Inspiratory muscle training (IMT) has been used as part of athletic training. It is beneficial due to an increase in respiratory capacity, and can be related to the optimization of exercise tolerance. There are a growing number of publications on the subject, however the methodological rigor of these publications is still unknown. Objective: To perform a systematic literature review in order to analyze the effects of Powerbreathe® on inspiratory muscle training by athletes. Methods: Original scientific studies published in English, from 2000 to 2015, were included. Their typology was classified. The literature search was performed in the Lilacs, Medline, Pubmed, and Scielo databases using the following keywords: inspiratory muscle training, athletes, and Sports medicine (in English), treinamento muscular inspiratório, atleta, medicina esportiva (in Portuguese). Results: Inspiratory muscle training with specific linear resistance has been used in some athletic training, and its results are promising. However, its application is still recent and generally supported by experiments with limited population and which do not properly define the confounding factors for the results. Conclusion: The state of the art suggests that IMT is useful as a respiratory therapy supporting the training of athletes for some specific sports. However, there is a scarcity of studies of high methodological quality, thus requiring further experiments on the subject.

Inspiratory muscle training to enhance recovery from mechanical ventilation: a randomised trial

Background

In patients who have been mechanically ventilated, inspiratory muscles remain weak and fatigable following ventilatory weaning, which may contribute to dyspnoea and limited functional recovery. Inspiratory muscle training may improve inspiratory muscle strength and endurance following weaning, potentially improving dyspnoea and quality of life in this patient group.

Methods

We conducted a randomised trial with assessor-blinding and intention-to-treat analysis. Following 48 hours of successful weaning, 70 participants (mechanically ventilated ≥7 days) were randomised to receive inspiratory muscle training once daily 5 days/week for 2 weeks in addition to usual care, or usual care (control). Primary endpoints were inspiratory muscle strength and fatigue resistance index (FRI) 2 weeks following enrolment. Secondary endpoints included dyspnoea, physical function and quality of life, post-intensive care length of stay and in-hospital mortality.

Results

34 participants were randomly allocated to the training group and 36 to control. The training group demonstrated greater improvements in inspiratory strength (training: 17%, control: 6%, mean difference: 11%, p=0.02). There were no statistically significant differences in FRI (0.03 vs 0.02, p=0.81), physical function (0.25 vs 0.25, p=0.97) or dyspnoea (−0.5 vs 0.2, p=0.22). Improvement in quality of life was greater in the training group (14% vs 2%, mean difference 12%, p=0.03). In-hospital mortality was higher in the training group (4 vs 0, 12% vs 0%, p=0.051).

Conclusions

Inspiratory muscle training following successful weaning increases inspiratory muscle strength and quality of life, but we cannot confidently rule out an associated increased risk of in-hospital mortality.

Trial registration number

ACTRN12610001089022, results.

Strategies to optimize respiratory muscle function in ICU patients

Respiratory muscle dysfunction may develop rapidly in critically ill ventilated patients and is associated with increased morbidity, length of intensive care unit stay, costs, and mortality. This review briefly discusses the pathophysiology of respiratory muscle dysfunction in intensive care unit patients and then focuses on strategies that prevent the development of muscle weakness or, if weakness has developed, how respiratory muscle function may be improved. We propose a simple strategy for how these can be implemented in clinical care.

Influence of inspiratory muscle training on weaning patients from mechanical ventilation: a systematic review

Abstract Introduction: The inability of respiratory muscles to generate force and endurance is recognized as an important cause of failure in weaning patients from invasive mechanical ventilation (IMV). Thus, inspiratory muscle training (IMT) might be an interesting treatment option for patients with prolonged IMV weaning. Objective: The aim of this systematic literature review was to evaluate the effectiveness of inspiratory muscle training in weaning patients from mechanical ventilation and to identify the most effective type of training for this particular purpose. Methods: We searched PubMed, LILACS, PEDro and Web of Science for randomized clinical trials published in English or Portuguese from January 1990 until March 2015. Results: Eighty-nine studies were identified of which five were selected. A total of 267 patients participated in the five randomized clinical trials analyzed here. IMV duration before onset of training varied greatly among subjects. Three studies performed IMT using a threshold device and two studies used adjustments of ventilator pressure sensitivity. Four studies have shown that IMT resulted in a significant increase in inspiratory maximal pressure. Only two studies, however, have reported that IMT resulted in higher success rates in weaning patients from IMV. One study has found that patients showed a shorter ventilator weaning duration after IMT. Conclusion: IMT using pressure threshold devices results in increased inspiratory muscle strength and can therefore be considered a more effective treatment option and with the potential to optimize ventilator weaning success in patients at risk of prolonged IMV.

Inspiratory muscle training is used in some intensive care units, but many training methods have uncertain efficacy: a survey of French physiotherapists

QUESTIONS

How common is inspiratory muscle training by physiotherapists in the intensive care unit (ICU)? Which patients receive the training? What methods are used to administer the training? Is maximal inspiratory pressure used to evaluate the need for the training and the patient's outcome after training?

DESIGN

Cross-sectional survey of all ICUs in France.

PARTICIPANTS

Two hundred and sixty-five senior physiotherapists.

RESULTS

The response rate was 99% among eligible units. Therapist experience in ICU was significantly associated with the use of inspiratory muscle training (p=0.02). Therapists mainly used inspiratory muscle training either systematically or specifically in patients who failed to wean from mechanical ventilation. The training was used significantly more in non-sedated patients (p<0.0001). The most commonly nominated technique that respondents claimed to use to apply the training was controlled diaphragmatic breathing (83% of respondents), whereas 13% used evidence-based methods. Among those who applied some form of inspiratory muscle training, 16% assessed maximal inspiratory pressure. Six respondents (2%, 95% CI 1 to 5) used both an evidence-based method to administer inspiratory muscle training and the recommended technique for assessment of inspiratory muscle strength.

CONCLUSION

Most physiotherapists in French ICUs who apply inspiratory muscle training use methods of uncertain efficacy without assessment of maximal inspiratory pressure. Further efforts need to be made in France to disseminate information regarding evidence-based assessment and techniques for inspiratory muscle training in the ICU. The alignment of inspiratory muscle training practice with evidence could be investigated in other regions.

Inspiratory muscle training facilitates weaning from mechanical ventilation among patients in the intensive care unit: a systematic review

QUESTION

Does inspiratory muscle training improve inspiratory muscle strength in adults receiving mechanical ventilation? Does it improve the duration or success of weaning? Does it affect length of stay, reintubation, tracheostomy, survival, or the need for post-extubation non-invasive ventilation? Is it tolerable and does it cause adverse events?

DESIGN

Systematic review of randomised trials.

PARTICIPANTS

Adults receiving mechanical ventilation.

INTERVENTION

Inspiratory muscle training versus sham or no inspiratory muscle training.

OUTCOME MEASURES

Data were extracted regarding: inspiratory muscle strength and endurance; the rapid shallow breathing index; weaning success and duration; duration of mechanical ventilation; reintubation; tracheostomy; length of stay; use of non-invasive ventilation after extubation; survival; readmission; tolerability and adverse events.

RESULTS

Ten studies involving 394 participants were included. Heterogeneity within some meta-analyses was high. Random-effects meta-analyses showed that the training significantly improved maximal inspiratory pressure (MD 7 cmH2O, 95% CI 5 to 9), the rapid shallow breathing index (MD 15 breaths/min/l, 95% CI 8 to 23) and weaning success (RR 1.34, 95% CI 1.02 to 1.76). Although only assessed in individual studies, significant benefits were also reported for the time spent on non-invasive ventilation after weaning (MD 16 hours, 95% CI 13 to 18), length of stay in the intensive care unit (MD 4.5 days, 95% CI 3.6 to 5.4) and length of stay in hospital (MD 4.4 days, 95% CI 3.4 to 5.5). Weaning duration decreased in the subgroup of patients with known weaning difficulty. The other outcomes weren't significantly affected or weren't measured.

CONCLUSION

Inspiratory muscle training for selected patients in the intensive care unit facilitates weaning, with potential reductions in length of stay and the duration of non-invasive ventilatory support after extubation. The heterogeneity among the results suggests that the effects of inspiratory muscle training may vary; this perhaps depends on factors such as the components of usual care or the patient's characteristics.