Shrinking Lung Syndrome: A Rare Pulmonary Complication of Systemic Lupus Erythematosus.

Shrinking lung syndrome (SLS) is a rare pulmonary complication primarily associated with autoimmune diseases such as systemic lupus erythematosus (SLE). A 38-year-old female recently diagnosed with SLE on hydroxychloroquine, prednisone, and methotrexate presented with a one-week history of progressive shortness of breath, non-productive cough, and pleuritic chest pain. She was afebrile with adequate oxygen saturation. Examination revealed a few fine crackles in the lung fields. Laboratory results showed pancytopenia. Initial treatment included broad-spectrum antibiotics and intravenous methylprednisolone for a suspected lupus flare. Cultures and tests for infections, including tuberculosis, were negative. Imaging revealed bilateral airspace disease with no pulmonary embolism. Autoimmune workup showed high antinuclear antibodies, positive anticardiolipin antibody, ribonucleoprotein, and anti-Smith antibody. Diagnosed with SLS, she was started on a tapering dose of methylprednisolone and hydroxychloroquine, along with rituximab, leading to significant improvement. Pulmonary function tests (PFTs) showed a restrictive pattern. SLS, with a very low prevalence in SLE, can also occur in systemic sclerosis, Sjogren's syndrome, and rheumatoid arthritis. Typical symptoms include dyspnea, pleuritic chest pain, and cough. Diagnosis involves chest radiography showing an elevated diaphragm and restrictive PFT pattern. Treatment often includes corticosteroids such as methylprednisolone and immunosuppressive agents. Rituximab has shown improvement in cases unresponsive to conventional therapy.

The ReInvigorate Study-phrenic nerve-to-diaphragm stimulation for weaning from mechanical ventilation: a protocol for a randomized pivotal clinical trial.

BACKGROUND: In the United States in 2017, there were an estimated 903,745 hospitalizations involving mechanical ventilation (MV). Complications from ventilation can result in longer hospital stays, increased risk of disability, and increased healthcare costs. It has been hypothesized that electrically pacing the diaphragm by phrenic nerve stimulation during mechanical ventilation may minimize or reverse diaphragm dysfunction, resulting in faster weaning. METHODS: The ReInvigorate Trial is a prospective, multicenter, randomized, controlled clinical trial evaluating the safety and efficacy of Stimdia's pdSTIM System for facilitating weaning from MV. The pdSTIM system employs percutaneously placed multipolar electrodes to stimulate the cervical phrenic nerves and activate contraction of the diaphragm bilaterally. Patients who were on mechanical ventilation for at least 96 h and who failed at least one weaning attempt were considered for enrollment in the study. The primary efficacy endpoint was the time to successful liberation from mechanical ventilation (treatment vs. control). Secondary endpoints will include the rapid shallow breathing index and other physiological and system characteristics. Safety will be summarized for both primary and additional analyses. All endpoints will be evaluated at 30 days or at the time of removal of mechanical ventilation, whichever is first. DISCUSSION: This pivotal study is being conducted under an investigational device exception with the U.S. Food and Drug Administration. The technology being studied could provide a first-of-kind therapy for difficult-to-wean patients on mechanical ventilation in an intensive care unit setting. TRIAL REGISTRATION: Clinicaltrials.gov, NCT05998018 , registered August 2023.

Unilateral Diaphragmatic Paralysis: A Case Report of an Often Overlooked Diagnosis.

Unilateral diaphragmatic paralysis, resulting from nerve or muscle injuries, is an uncommon phenomenon often missed due to its asymptomatic nature. This condition can lead to decreased pulmonary function, particularly in patients with underlying comorbidities or cardiopulmonary issues. Identification and understanding of the underlying cause of the paralysis are essential for effective management and improved patient outcomes. Here, we present a case of a 49-year-old male who presented with left flank pain and complained of dyspnea on exertion. Further workup and a sniff test confirmed the diagnosis of left hemidiaphragm paralysis.

Diaphragm and Lung Transplantation.

Mutual interactions between the diaphragm and lung transplantation (LTx) are known to exist. Before LTx, many factors can exert notable impact on the diaphragmatic function, such as the underlying respiratory disease, the comorbidities, and the chronic treatments of the patient. In the post-LTx setting, even the surgical procedure itself can cause a stressful trauma to the diaphragm, potentially leading to morphological and functional alterations. Conversely, the diaphragm can significantly influence various aspects of the LTx process, ranging from graft-to-chest cavity size matching to the long-term postoperative respiratory performance of the recipient. Despite this, there are still no standard criteria for evaluating, defining, and managing diaphragmatic dysfunction in the context of LTx to date. This deficiency hampers the accurate assessment of those factors which affect the diaphragm and its reciprocal influence on LTx outcomes. The objective of this narrative review is to delve into the complex role the diaphragm plays in the different stages of LTx and into the modifications of this muscle following surgery.

Bi-parametric MRI of the Diaphragm Using Dynamic and Static Images: The Initial Experience.

BACKGROUND: With recent technological advances, magnetic resonance imaging (MRI) has offered new sequences that can evaluate the real-time motion of anatomic structures. This study aims to evaluate the interobserver agreement in the diagnosis of diaphragmatic dysfunctions using bi-parametric MRI, in which dynamic sequences for diaphragm movement and static sequences for soft tissue resolution are used together to provide a visualization of the diaphragm. METHODOLOGY: Twenty-nine cases that underwent a bi-parametric magnetic resonance examination which includes coronal T2 single-shot turbo spin echo and the coronal SENSE single-shot balanced turbo field echo real-time sequences were retrospectively evaluated. The images of the patients were assessed by two independent observers. Cohen's kappa coefficient was calculated to evaluate the interobserver agreement. RESULTS: The mean age of the patients was 44.86 ± 17.57, ranging from 18 to 80 years. The kappa value was calculated as 0.889, indicating a strong agreement between the interobservers. CONCLUSIONS: Our experience suggests that bi-parametric MRI is a promising tool in the evaluation of diaphragmatic abnormalities.

Ultrasound assessment of diaphragmatic dysfunction in non-critically ill patients: relevant indicators and update.

Diaphragm dysfunction (DD) can be classified as mild, resulting in diaphragmatic weakness, or severe, resulting in diaphragmatic paralysis. Various factors such as prolonged mechanical ventilation, surgical trauma, and inflammation can cause diaphragmatic injury, leading to negative outcomes for patients, including extended bed rest and increased risk of pulmonary complications. Therefore, it is crucial to protect and monitor diaphragmatic function. Impaired diaphragmatic function directly impacts ventilation, as the diaphragm is the primary muscle involved in inhalation. Even unilateral DD can cause ventilation abnormalities, which in turn lead to impaired gas exchange, this makes weaning from mechanical ventilation challenging and contributes to a higher incidence of ventilator-induced diaphragm dysfunction and prolonged ICU stays. However, there is insufficient research on DD in non-ICU patients, and DD can occur in all phases of the perioperative period. Furthermore, the current literature lacks standardized ultrasound indicators and diagnostic criteria for assessing diaphragmatic dysfunction. As a result, the full potential of diaphragmatic ultrasound parameters in quickly and accurately assessing diaphragmatic function and guiding diagnostic and therapeutic decisions has not been realized.

Diaphragmatic dysfunction is associated with postoperative pulmonary complications in the aged patients underwent radical resection of esophageal cancer: a prospective observational study.

Background: Diaphragmatic dysfunction escalates the susceptibility to postoperative pulmonary complications (PPCs). Currently, no study reports the occurrence of diaphragmatic dysfunction correlated with PPCs following radical resection of esophageal cancer in aged patients. We aimed to diagnose diaphragmatic dysfunction via ultrasonography and analyze diaphragmatic dysfunction's relation with PPCs after radical resection of esophageal cancer surgery in aged patients. Methods: This prospective observational study comprised 86 aged patients undergoing radical resection of esophageal cancer. Patient characteristics data and intraoperative details were collected. Ultrasonography was performed before (preoperative) and after (first, third, and fifth day postoperatively) surgery. Outcome measures included PPCs within seven days postoperative, occurrence of diaphragmatic dysfunction, and short-term prognosis. Results: After excluding 14 patients, we finally analyzed clinical data from 72 patients. The prevalence of PPCs was higher in the patients with diaphragmatic dysfunction than those without (19 of 23, 83% vs. 21 of 49, 43%, P=0.004). Postoperative diaphragmatic dysfunction was positively correlated with PPCs in patients who underwent elective radical esophageal cancer surgery (r=0.37, P=0.001). Persistent diaphragmatic dysfunction, furthermore, was positively correlated with the development of multiple PPCs (r=0.43, P<0.001). The logistic regression analysis revealed that age, total open procedure, and postoperative diaphragmatic dysfunction were identified as significant risk factors for PPCs, while total open procedure was an independent risk factor for diaphragmatic dysfunction. Conclusions: Postoperative diaphragmatic dysfunction positively correlates with developing PPCs. Continuous monitoring of postoperative diaphragmatic function can screen high-risk patients with PPCs, which has specific clinical significance. Age, total open procedure, and diaphragmatic dysfunction are identified as risk factors for developing PPCs, while total open procedure specifically increases the risk for postoperative diaphragmatic dysfunction.

Suppression of Ventilation-Induced Diaphragm Fibrosis through the Phosphoinositide 3-Kinase-γ in a Murine Bleomycin-Induced Acute Lung Injury Model.

Mechanical ventilation (MV), used in patients with acute lung injury (ALI), induces diaphragmatic myofiber atrophy and contractile inactivity, termed ventilator-induced diaphragm dysfunction. Phosphoinositide 3-kinase-γ (PI3K-γ) is crucial in modulating fibrogenesis during the reparative phase of ALI; however, the mechanisms regulating the interactions among MV, myofiber fibrosis, and PI3K-γ remain unclear. We hypothesized that MV with or without bleomycin treatment would increase diaphragm muscle fibrosis through the PI3K-γ pathway. Five days after receiving a single bolus of 0.075 units of bleomycin intratracheally, C57BL/6 mice were exposed to 6 or 10 mL/kg of MV for 8 h after receiving 5 mg/kg of AS605240 intraperitoneally. In wild-type mice, bleomycin exposure followed by MV 10 mL/kg prompted significant increases in disruptions of diaphragmatic myofibrillar organization, transforming growth factor-ß1, oxidative loads, Masson's trichrome staining, extracellular collagen levels, positive staining of α-smooth muscle actin, PI3K-γ expression, and myonuclear apoptosis (p < 0.05). Decreased diaphragm contractility and peroxisome proliferator-activated receptor-γ coactivator-1α levels were also observed (p < 0.05). MV-augmented bleomycin-induced diaphragm fibrosis and myonuclear apoptosis were attenuated in PI3K-γ-deficient mice and through AS605240-induced inhibition of PI3K-γ activity (p < 0.05). MV-augmented diaphragm fibrosis after bleomycin-induced ALI is partially mediated by PI3K-γ. Therapy targeting PI3K-γ may ameliorate MV-associated diaphragm fibrosis.

Diaphragm Ultrasound in Different Clinical Scenarios: A Review with a Focus on Older Patients.

Diaphragm muscle dysfunction is increasingly recognized as a fundamental marker of several age-related diseases and conditions including chronic obstructive pulmonary disease, heart failure and critical illness with respiratory failure. In older individuals with physical frailty and sarcopenia, the loss of muscle mass and function may also involve the diaphragm, contributing to respiratory dysfunction. Ultrasound has recently emerged as a feasible and reliable strategy to visualize diaphragm structure and function. In particular, it can help to predict the timing of extubation in patients undergoing mechanical ventilation in intensive care units (ICUs). Ultrasonographic evaluation of diaphragmatic function is relatively cheap, safe and quick and can provide useful information for real-time monitoring of respiratory function. In this review, we aim to present the current state of scientific evidence on the usefulness of ultrasound in the assessment of diaphragm dysfunction in different clinical settings, with a particular focus on older patients. We highlight the importance of the qualitative information gathered by ultrasound to assess the integrity, excursion, thickness and thickening of the diaphragm. The implementation of bedside diaphragm ultrasound could be useful for improving the quality and appropriateness of care, especially in older subjects with sarcopenia who experience acute respiratory failure, not only in the ICU setting.

Dyssynchronous diaphragm contractions impair diaphragm function in mechanically ventilated patients.

BACKGROUND: Pre-clinical studies suggest that dyssynchronous diaphragm contractions during mechanical ventilation may cause acute diaphragm dysfunction. We aimed to describe the variability in diaphragm contractile loading conditions during mechanical ventilation and to establish whether dyssynchronous diaphragm contractions are associated with the development of impaired diaphragm dysfunction. METHODS: In patients receiving invasive mechanical ventilation for pneumonia, septic shock, acute respiratory distress syndrome, or acute brain injury, airway flow and pressure and diaphragm electrical activity (Edi) were recorded hourly around the clock for up to 7 days. Dyssynchronous post-inspiratory diaphragm loading was defined based on the duration of neural inspiration after expiratory cycling of the ventilator. Diaphragm function was assessed on a daily basis by neuromuscular coupling (NMC, the ratio of transdiaphragmatic pressure to diaphragm electrical activity). RESULTS: A total of 4508 hourly recordings were collected in 45 patients. Edi was low or absent (≤ 5 µV) in 51% of study hours (median 71 h per patient, interquartile range 39-101 h). Dyssynchronous post-inspiratory loading was present in 13% of study hours (median 7 h per patient, interquartile range 2-22 h). The probability of dyssynchronous post-inspiratory loading was increased with reverse triggering (odds ratio 15, 95% CI 8-35) and premature cycling (odds ratio 8, 95% CI 6-10). The duration and magnitude of dyssynchronous post-inspiratory loading were associated with a progressive decline in diaphragm NMC (p < 0.01 for interaction with time). CONCLUSIONS: Dyssynchronous diaphragm contractions may impair diaphragm function during mechanical ventilation. TRIAL REGISTRATION: MYOTRAUMA, ClinicalTrials.gov NCT03108118. Registered 04 April 2017 (retrospectively registered).

Clinical correlates of respiratory disorders in patients with severe multiple sclerosis: A cross-sectional cohort.

BACKGROUND: Respiratory disorders remain incompletely described in multiple sclerosis (MS), even though they are a frequent cause of death. METHODS: The objective was to describe respiratory disorders in MS patients with Expanded Disability Status Score (EDSS) ⩾ 6.5. Diaphragm dysfunction was defined by at least two of the seven criteria: clinical signs, inspiratory recruitment of neck muscles during wakefulness, reduced upright vital capacity (VC) < 80%, upright-to-supine VC ⩾ 15% of upright VC, decrease in Maximal Inspiratory Pressure < 60%, phasic activation of inspiratory neck muscles during sleep, and opposition of thoracic and abdominal movements during sleep. Cough weakness was defined by a peak cough flow < 270 L/min and/or need for cough assist. Sleep apnea syndrome was defined by an apnea-hypopnea index ⩾ 15. RESULTS: Notably, 71 MS patients were included: median age 54 [48, 61] years; median disease duration 21.4 [16.0, 31.4] years. Of these, 52 patients had one or more respiratory disorders; diaphragm dysfunction was the most frequent (n = 34). Patients with diaphragm dysfunction and cough weakness were more disabled. The fatigue score and the cognitive evaluations did not differ between the groups. Five patients required non-invasive ventilation. CONCLUSION: Respiratory disorders are frequent in severe MS, mostly diaphragm dysfunction. Of interest, instrumental interventions are available to address these disorders.

Computational Drug Discovery in Diaphragm Dysfunction via Text Mining and Biomedical Database.

The diaphragm, which is crucial for ventilation, is the primary muscle responsible for inspiration. Patients with severe burns who experience diaphragmatic dysfunction have an increased risk of mortality. Unfortunately, there are currently no effective medications available to prevent or treat this condition. The objective of our study is to utilize bioinformatics to identify potential genes and drugs associated with diaphragmatic dysfunction. In this study, text-mining techniques were utilized to identify genes associated with diaphragmatic dysfunction and recovery. Common genes were then analyzed using GO and KEGG pathway analysis, as well as protein-protein interaction network analysis. The obtained hub genes were processed using Cytoscape software, and their expression levels in diaphragmatic dysfunction were validated using quantitative real-time polymerase chain reaction (qRT-PCR) in severe burn rats. Genes that were confirmed were then examined in drug-gene interaction databases to identify potential drugs associated with these genes. Our analysis revealed 96 genes that were common to both the "diaphragm dysfunction" and "functional recovery" text mining concepts. Gene enrichment analysis identified 19 genes representing 10 pathways. qRT-PCR showed a significant increase in expression levels of 13 genes, including CCL2, CCL3, CD4, EGF, HGF, IFNG, IGF1, IL17A, IL6, LEP, PTGS2, TGFB1, and TNF, in samples with diaphragmatic dysfunction. Additionally, we found that a total of 56 drugs targeted 5 potential genes. These findings provide new insights into the development of more effective drugs for treating diaphragmatic dysfunction and also present substantial opportunities for researching new target pharmacology and promoting drugs in the pharmaceutical industry.

Diaphragm atrophy during invasive mechanical ventilation is related to extubation failure in preterm infants: An ultrasound study.

BACKGROUND: Diaphragm dysfunction is associated with poor outcomes in critically ill patients. Ventilator-induced diaphragmatic dysfunction (VIDD), including diaphragm atrophy (DA), is poorly studied in newborns. We aimed to assess VIDD and its associations in newborns. METHODS: Single-center prospective study. Diaphragm thickness was measured at end-inspiration (TDI) and end-expiration (TDE) on the right midaxillary line. DA was defined as decrease in TDE ≥ 10%. Daily measurements were recorded in preterm newborns on invasive mechanical ventilation (IMV) for ≥2 days. Clinical characteristics of patients and extubation failure were recorded. Univariate analysis, logistic regression, and mixed models were performed to describe VIDD and associated factors. RESULTS: We studied 17 patients (median gestational age 270/7 weeks) and 22 IMV cycles (median duration 9 days). Median TDE decreased from 0.118 cm (interquartile range [IQR] 0.094-0.165) on the first IMV day to 0.104 cm (IQR 0.083-0.120) on the last IMV day (p = .092). DA occurred in 11 IMV cycles (50%) from 10 infants early during IMV (median: second IMV day). Mean airway pressure (MAP) and lung ultrasound score (LUS) on the first IMV day were significantly higher in patients who developed DA. DA was more frequent in patients with extubation failure than in those with extubation success within 7 days (83.3 vs. 33.3%, p = .038). CONCLUSIONS: DA, significantly associated with extubation failure, occurred in 58.8% of the study infants on IMV. Higher MAP and LUS at IMV start were associated with DA. Our results suggest a potential role of diaphragm ultrasound to assess DA and predict extubation failure in clinical practice.

Rapid review of ventilator-induced diaphragm dysfunction.

Ventilator-induced diaphragm dysfunction is gaining increased recognition. Evidence of diaphragm weakness can manifest within 12 h to a few days after the initiation of mechanical ventilation. Various noninvasive and invasive methods have been developed to assess diaphragm function. The implementation of diaphragm-protective ventilation strategies is crucial for preventing diaphragm injuries. Furthermore, diaphragm neurostimulation emerges as a promising and novel treatment option. In this rapid review, our objective is to discuss the current understanding of ventilator-induced diaphragm dysfunction, diagnostic approaches, and updates on strategies for prevention and management.

Effect of post-extubation inspiratory muscle training on diaphragmatic function in mechanically ventilated patients: A randomized controlled trial.

BACKGROUND: Diaphragmatic dysfunction is a common problem in patients who have been mechanically ventilated. OBJECTIVES: The study aimed to evaluate the effectiveness of inspiratory muscle training (IMT) on diaphragm muscle thickness and function in mechanically ventilated patients. MATERIAL AND METHODS: A single-blind trial was conducted. Twenty patients were randomly assigned to either the conventional physiotherapy (CP) group or to the IMT group for 5 days following extubation. The CP group received only CP, while the IMT group received CP in addition to IMT. Ten healthy controls (HCs) underwent IMT. Maximum inspiratory pressure (MIP) and physical function were recorded. Diaphragm excursion (DE), diaphragm thickness at the end of inspiration (Tdi), diaphragm thickness at the end of expiration (Tde), peak contraction velocity (PCV), and peak relaxation velocity (PRV) were evaluated with ultrasonography before and after the intervention. RESULTS: The IMT group and HCs showed significant improvements in DE (p = 0.005; p = 0.005, respectively), PCV (p = 0.028; p = 0.015, respectively) and PRV (p = 0.029; p = 0.020, respectively) after 5 days of IMT. A significant increase in MIP was recorded in all groups after the intervention (CP: p = 0.044; IMT: p = 0.005; HC: p < 0.001). There was a significant improvement in the Medical Research Council (MRC) and the Physical Function in Intensive Care Test (PFIT) scores in both the CP and IMT groups (p < 0.001 and p < 0.001, respectively). CONCLUSIONS: Inspiratory muscle training improves diaphragmatic functions, including MIP, diaphragm excursion, PCV, and PRV. We think that IMT applied after extubation may serve as a tool to prevent and facilitate the recovery of diaphragmatic function.

Respiratory Muscle Contraction Characteristics and Potential Mechanisms in Severely Burned Rats.

Postburn hypermetabolism remains an important clinical problem. During this phase, there is a significant loss of diaphragmatic proteins. Better understanding of respiratory muscle dynamics and potential mechanisms affecting respiratory muscle function is necessary for the development of effective therapeutic approaches. Male Wistar rats were subjected to 50% TBSA burns and sham injuries, and respiratory muscle function was assessed with 0, 1, 4, 7, and 14 days postinjury, including pulmonary function, blood gas analysis, transdiaphragmatic pressure, diaphragm ultrasonography, isolated diaphragm contractility, fatigue index, protein oxidative stress content, and ATP levels. Burned rats had significantly reduced inspiratory time, expiratory time, and tidal volume and significantly increased respiratory rate and minute ventilation. At the same time, the isolated diaphragm contractility, specific force during fatigue, and fatigue index were significantly decreased in the burned rats. Pdi, Pdimax, diaphragm thickness, diaphragm thickening fraction, and diaphragm excursion also decreased significantly postburn, whereas the Pdi/Pdimax ratio increased significantly. Finally, the content of protein carbonyls and lactic acid of burned rats was increased, and ATP levels of burned rats were decreased. The present study demonstrates the dynamic changes in diaphragm contractile properties postburn from both in vivo and in vitro perspectives, while cursorily exploring the possibility that protein oxidative stress and reduced ATP production may be the cause of diaphragm dysfunction. This understanding contributes to the development of methods to mitigate the extent of diaphragmatic function loss after severe burns.

Closed-loop parameter optimization for patient-specific phrenic nerve stimulation.

BACKGROUND: Ventilator-induced diaphragm dysfunction occurs rapidly following the onset of mechanical ventilation and has significant clinical consequences. Phrenic nerve stimulation has shown promise in maintaining diaphragm function by inducing diaphragm contractions. Non-invasive stimulation is an attractive option as it minimizes the procedural risks associated with invasive approaches. However, this method is limited by sensitivity to electrode position and inter-individual variability in stimulation thresholds. This makes clinical application challenging due to potentially time-consuming calibration processes to achieve reliable stimulation. METHODS: We applied non-invasive electrical stimulation to the phrenic nerve in the neck in healthy volunteers. A closed-loop system recorded the respiratory flow produced by stimulation and automatically adjusted the electrode position and stimulation amplitude based on the respiratory response. By iterating over electrodes, the optimal electrode was selected. A binary search method over stimulation amplitudes was then employed to determine an individualized stimulation threshold. Pulse trains above this threshold were delivered to produce diaphragm contraction. RESULTS: Nine healthy volunteers were recruited. Mean threshold stimulation amplitude was 36.17 ± 14.34 mA (range 19.38-59.06 mA). The threshold amplitude for reliable nerve capture was moderately correlated with BMI (Pearson's r = 0.66, p = 0.049). Repeating threshold measurements within subjects demonstrated low intra-subject variability of 2.15 ± 1.61 mA between maximum and minimum thresholds on repeated trials. Bilateral stimulation with individually optimized parameters generated reliable diaphragm contraction, resulting in significant inhaled volumes following stimulation. CONCLUSION: We demonstrate the feasibility of a system for automatic optimization of electrode position and stimulation parameters using a closed-loop system. This opens the possibility of easily deployable individualized stimulation in the intensive care setting to reduce ventilator-induced diaphragm dysfunction.

Effect of sling exercise therapy on ventilator-induced diaphragm dysfunction in patients with mechanical ventilation / 中国实用护理杂志

Objective:To investigate the intervention effect of sling exercise therapy on ventilator-induced diaphragm dysfunction (VIDD) in patients with mechanical ventilation, and to provide the reference for prevention and treatment of VIDD.Methods:By a prospective randomized controlled study method, a total of 74 mechanical ventilation patients in Guangzhou Red Cross Hospital from July 2022 to July 2023 were convenient selected, they were divided into the experimental group and the control group according to the random number table method with 37 cases in each group. Both groups were given routine nursing care, the control group carried out early rehabilitation exercise, the experimental group implemented sling exercise therapy. The diaphragm function, respiratory function after the different time of intervention, and outcome events were compared between two groups.Results:Finally, the experimental group included 34 cases, 22 males and 12 females, aged (55.50 ± 12.03) years old. The control group included 36 cases, 25 males and 11 females, aged (54.78 ± 12.81) years old. There was no significant difference in the diaphragm function, respiratory function before intervention(all P>0.05). After 7 d of intervention, the diaphragmatic excursion, diaphragm thickening fraction were (1.59 ± 0.21) cm, (45.90 ± 5.20) % in the experimental group, which were higher than those in the control group (1.49 ± 0.21) cm, (42.78 ± 5.51) %, the differences were statistically significant ( t=2.13, 2.44, both P<0.05). After 5, 7 d of intervention, the rapid shallow breathing index was (81.47 ± 6.97), (77.29 ± 8.91) times. min -1.L -1 in the experimental group, which were lower than those in the control group (88.36 ± 9.04), (84.67 ± 9.64) times.min -1.L -1; after 3, 5, 7 d on intervention, the oxygenation index was (230.79 ± 44.79), (241.59 ± 23.79), (258.56 ± 23.09) mmHg(1 mmHg=0.133 kPa) in the experimental group, which were higher than those in the control group (197.25 ± 21.21), (212.72 ± 21.81), (242.75 ± 24.37) mmHg, the differences were statistically significant ( t values were 2.78-5.30, all P<0.05). The mechanical ventilator time and the length of stay in ICU were (225.29 ± 47.31) h, (12.47 ± 3.71) d in the experimental group, which were lower than those in the control group (260.53 ± 56.32) h, (14.64 ± 4.53) d, the differences were statistically significant ( t=2.83, 2.18, both P<0.05). The incidence rate of VIDD was 5.9%(2/34) in the experimental group, which was lower than that in the control group 22.2%(8/36), and the weaning success rate was 91.2%(31/34) in the experimental group, which was higher than that in the control group 72.2% (26/36), the differences were statistically significant ( χ2=4.18, 4.15, both P<0.05). Conclusions:Sling exercise therapy can effectively promote diaphragm function and respiratory function, shorten mechanical ventilator time and the length of stay in ICU of patients with mechanical ventilation, and reduce the occurrence of VIDD.

Research progress on the pathogenesis and treatment of ventilator-induced diaphragm dysfunction.

Prolonged controlled mechanical ventilation (CMV) can cause diaphragm fiber atrophy and inspiratory muscle weakness, resulting in diaphragmatic contractile dysfunction, called ventilator-induced diaphragm dysfunction (VIDD). VIDD is associated with higher rates of in-hospital deaths, nosocomial pneumonia, difficulty weaning from ventilators, and increased costs. Currently, appropriate clinical strategies to prevent and treat VIDD are unavailable, necessitating the importance of exploring the mechanisms of VIDD and suitable treatment options to reduce the healthcare burden. Numerous animal studies have demonstrated that ventilator-induced diaphragm dysfunction is associated with oxidative stress, increased protein hydrolysis, disuse atrophy, and calcium ion disorders. Therefore, this article summarizes the molecular pathogenesis and treatment of ventilator-induced diaphragm dysfunction in recent years so that it can be better served clinically and is essential to reduce the duration of mechanical ventilation use, intensive care unit (ICU) length of stay, and the medical burden.

Cellular senescence contributes to mechanical ventilation-induced diaphragm dysfunction by upregulating p53 signalling pathways.

BACKGROUND: Mechanical ventilation can cause acute atrophy and injury in the diaphragm, which are related to adverse clinical results. However, the underlying mechanisms of ventilation-induced diaphragm dysfunction (VIDD) have not been well elucidated. The current study aimed to explore the role of cellular senescence in VIDD. METHODS: A total of twelve New Zealand rabbits were randomly divided into 2 groups: (1) spontaneously breathing anaesthetized animals (the CON group) and (2) mechanically ventilated animals (for 48 h) in V-ACV mode (the MV group). Respiratory parameters were collected during ventilation. Diaphragm were collected for further analyses. RESULTS: Compared to those in the CON group, the percentage and density of sarcomere disruption in the MV group were much higher (p < 0.001, both). The mRNA expression of MAFbx and MuRF1 was upregulated in the MV group (p = 0.003 and p = 0.006, respectively). Compared to that in the CON group, the expression of MAFbx and MuRF1 detected by western blotting was also upregulated (p = 0.02 and p = 0.03, respectively). Moreover, RNA-seq showed that genes associated with senescence were remarkably enriched in the MV group. The mRNA expression of related genes was further verified by q-PCR (Pai1: p = 0.009; MMP9: p = 0.008). Transverse cross-sections of diaphragm myofibrils in the MV group showed more intensive positive staining of SA-ßGal than those in the CON group. p53-p21 axis signalling was elevated in the MV group. The mRNA expression of p53 and p21 was significantly upregulated (p = 0.02 and p = 0.05, respectively). The western blot results also showed upregulation of p53 and p21 protein expression (p = 0.03 and p = 0.05, respectively). Moreover, the p21-positive staining in immunofluorescence and immunohistochemistry in the MV group was much more intense than that in the CON group (p < 0.001, both). CONCLUSIONS: In a rabbit model, we demonstrated that mechanical ventilation in A/C mode for 48 h can still significantly induce ultrastructural damage and atrophy of the diaphragm. Moreover, p53-dependent senescence might play a role in mechanical ventilation-induced dysfunction. These findings might provide novel therapeutic targets for VIDD.