Diaphragmatic Dysfunction Research Articles

Ventilator-induced diaphragm dysfunction: phenomenology and mechanism(s) of pathogenesis.

Mechanical ventilation (MV) is used to support ventilation and pulmonary gas exchange in patients during critical illness and surgery. Although MV is a life-saving intervention for patients in respiratory failure, an unintended side-effect of MV is the rapid development of diaphragmatic atrophy and contractile dysfunction. This MV-induced diaphragmatic weakness is labelled as 'ventilator-induced diaphragm dysfunction' (VIDD). VIDD is an important clinical problem because diaphragmatic weakness is a risk factor for the failure to wean patients from MV. Indeed, the inability to remove patients from ventilator support results in prolonged hospitalization and increased morbidity and mortality. The pathogenesis of VIDD has been extensively investigated, revealing that increased mitochondrial production of reactive oxygen species within diaphragm muscle fibres promotes a cascade of redox-regulated signalling events leading to both accelerated proteolysis and depressed protein synthesis. Together, these events promote the rapid development of diaphragmatic atrophy and contractile dysfunction. This review highlights the MV-induced changes in the structure/function of diaphragm muscle and discusses the cell-signalling mechanisms responsible for the pathogenesis of VIDD. This report concludes with a discussion of potential therapeutic opportunities to prevent VIDD and suggestions for future research in this exciting field.

Predicting Successful Weaning through Sonographic Measurement of the Rapid Shallow Breathing Index.

Background: Diaphragmatic dysfunction correlates with weaning failure, highlighting the need to independently assess the diaphragm's effects on weaning. We modified the rapid shallow breathing index (RSBI), a predictor of successful weaning, by incorporating temporal variables into existing ultrasound-derived diaphragm index to create a simpler index closer to tidal volume. Methods: We conducted a prospective observational study of patients who underwent a spontaneous breathing trial in the medical intensive care unit (ICU) at Severance Hospital between October 2022 and June 2023. Diaphragmatic displacement (DD) and diaphragm inspiratory time (Ti) were measured using lung ultrasonography. The modified RSBI was defined as follows: respiratory rate (RR) divided by DD was defined as D-RSBI, and RR divided by the sum of the products of DD and Ti on both sides was defined as DTi-RSBI. Results: Among the sonographic indices, DTi-RSBI had the highest area under the receiver operating characteristic (ROC) curve of 0.774 in ROC analysis, and a correlation was found between increased DTi-RSBI and unsuccessful extubation in a multivariable logistic regression analysis (adjusted odds ratio 0.02, 95% confidence interval 0.00-0.97). Conclusions: The DTi-RSBI is beneficial in predicting successful weaning in medical ICU patients.

Diaphragmatic muscle dysfunction associated with artificial mechanical ventilation: a narrative review of the literature

Mechanical ventilation is a respiratory support therapy that can cause diaphragm muscle injury and induce dysfunction, which is associated with prolonged ventilation, weaning failure and mortality. Protecting the diaphragm during ventilation requires the use of tools to monitor diaphragmatic effort. The aim of this review was to address current and relevant elements about the pathophysiology of diaphragmatic function in ventilated patients. For this purpose, a narrative review of the literature available in Google Scholar, Pumed/Medline, regional SciELO, and academic Google was carried out under the terms: diaphragmatic function-diaphragmatic function in ventilated patients/diaphragmatic ultrasound in ventilated patients pathophysiology/ diaphragmatic function and others. Fundamental theoretical contents on the clinic of diaphragmatic muscle dysfunction, its relationship with artificial ventilation and related structures, such as the lung, are addressed. It is concluded that the diaphragm represents the main muscle involved in respiration and diaphragmatic muscle dysfunction represents a frequent complication in critically ill patients. Diaphragmatic ultrasound is a tool that aids decision making on artificial ventilation, potentially reduces the duration of respiratory support and associated complications

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

BackgroundIn 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.MethodsThe 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.DiscussionThis 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 registrationClinicaltrials.gov, NCT05998018, registered August 2023.

Automated evaluation of diaphragm configuration based on chest CT in COPD patients

BackgroundSevere chronic obstructive pulmonary disease (COPD) often results in hyperinflation and flattening of the diaphragm. An automated computed tomography (CT)-based tool for quantifying diaphragm configuration, a biomarker for COPD, was developed in-house and tested in a large cohort of COPD patients.MethodsWe used the LungQ platform to extract the lung-diaphragm intersection, as direct diaphragm segmentation is challenging. The tool computed the diaphragm index (surface area/projected surface area) as a measure of diaphragm configuration on inspiratory scans in a COPDGene subcohort. Visual inspection of 250 randomly selected segmentations served as a quality check. Associations between the diaphragm index, Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages, forced expiratory volume in 1 s (FEV1) % predicted, and CT-derived emphysema scores were explored using analysis of variance and Pearson correlation.ResultsThe tool yielded incomplete segmentation in 9.2% (2.4% major defect, 6.8% minor defect) of 250 randomly selected cases. In 8431 COPDGene subjects (4240 healthy; 4191 COPD), the diaphragm index was increasingly lower with higher GOLD stages (never-smoked 1.83 ± 0.16; GOLD-0 1.79 ± 0.18; GOLD-1 1.71 ± 0.15; GOLD-2: 1.67 ± 0.16; GOLD-3 1.58 ± 0.14; GOLD-4 1.54 ± 0.11) (p < 0.001). Associations were found between the diaphragm index and both FEV1% predicted (r = 0.44, p < 0.001) and emphysema score (r = −0.36, p < 0.001).ConclusionWe developed an automated tool to quantify the diaphragm configuration in chest CT. The diaphragm index was associated with COPD severity, FEV1%predicted, and emphysema score.Relevance statementDue to the hypothesized relationship between diaphragm dysfunction and diaphragm configuration in COPD patients, automatic quantification of diaphragm configuration may prove useful in evaluating treatment efficacy in terms of lung volume reduction.Key PointsSevere COPD changes diaphragm configuration to a flattened state, impeding function.An automated tool quantified diaphragm configuration on chest-CT providing a diaphragm index.The diaphragm index was correlated to COPD severity and may aid treatment assessment.Graphical

Exploring diaphragmatic response to high-flow nasal cannula in patients with COVID-19 pneumonia using ultrasound: a proof of concept study.

Recent studies have highlighted the recognition of diaphragmatic dysfunction as a significant factor contributing to respiratory disturbances in severely ill COVID-19 patients. In the field of noninvasive respiratory support, high-flow nasal cannula (HFNC) has shown effectiveness in relieving diaphragm dysfunction. This study aims to investigate the diaphragmatic response to HFNC in patients with COVID-19 pneumonia by utilizing ultrasound. This retrospective study was conducted in a medical-surgical intensive care unit (ICU) at a tertiary care center in Buenos Aires, Argentina (Sanatorio de Los Arcos) over a 16-month period (January 2021-June 2022). The study included patients admitted to the ICU with a diagnosis of COVID-19 pneumonia who were deemed suitable candidates for HFNC therapy by the attending physician. Diaphragm ultrasound was conducted, measuring diaphragmatic excursion (DE) both before and during the utilization of HFNC for these patients. A total of 10 patients were included in the study. A statistically significant decrease in respiratory rate was observed with the use of HFNC (p = 0.02), accompanied by a significant increase in DE (p = 0.04). HFNC leads to a reduction in respiratory rate and an increase in DE as observed by ultrasound in patients with COVID-19 pneumonia, indicating promising enhancements in respiratory mechanics. However, further research is required to validate these findings.

Diaphragmatic Myopathy Associated with Dual Immune Checkpoint Inhibitors in a Patient with Renal Cell Carcinoma

ABSTRACT Immune-related adverse events (irAEs) have become increasingly prevalent with immune checkpoint inhibitor (ICI) cancer treatment. We present a 79-year-old man with metastatic renal cell carcinoma who developed shortness of breath and hypercapnic respiratory insufficiency after his first cycle of nivolumab and ipilimumab. Laboratory data showed elevated creatinine kinase, troponins, and transaminases. Computed tomography of the chest demonstrated bilateral lower lobe atelectasis. Heart catheterization and endomyocardial biopsy were unremarkable. Electromyogram (EMG) and nerve conduction studies (NCS) of the limb muscles revealed mild diffuse myopathy, normal sensory nerve conductions, and low-amplitude motor responses. Subsequent diaphragmatic EMG and NCS demonstrated severe myopathy. ICI-mediated myopathy predominantly affecting diaphragmatic muscles was diagnosed. Treatment included intravenous methylprednisolone, infliximab, abatacept, rituximab, and plasmapheresis. He underwent tracheostomy placement on hospital day 11 due to minimal improvement. He was discharged to a long-term acute care hospital, but unfortunately, he died less than 1 month later due to recurrent infections. irAEs can affect any organ system, but diaphragmatic dysfunction is uncommon. Use of diaphragmatic EMG, NCS, ultrasound study, or biopsy can support the diagnosis. Treatment includes systemic steroids, plasmapheresis, immunosuppressive medications, respiratory support, and cessation of causative medications. ICI-related diaphragmatic dysfunction should be suspected in those patients at risk with hypoxia, hypercapnia, or prolonged invasive or noninvasive ventilation without a distinct etiology. This case report exemplifies the importance of multidisciplinary workup and management of respiratory symptoms and insufficiency to identify and ameliorate irAEs. Diaphragmatic involvement can be associated with significant morbidity and mortality despite early aggressive multimodal therapy.

Weaning failure due to isolated residual diaphragmatic paralysis after cervical spinal cord ischemia following aortic surgery- a case report

BackgroundBilateral diaphragmatic dysfunction can lead to dyspnea and recurrent respiratory failure. In rare cases, it may result from high cervical spinal cord ischemia (SCI) due to anterior spinal artery syndrome (ASAS). We present a case of a patient experiencing persistent isolated diaphragmatic paralysis after SCI at level C3/C4 following thoracic endovascular aortic repair (TEVAR) for Kommerell’s diverticulum. This is, to our knowledge, the first documented instance of a patient fully recovering from tetraplegia due to SCI while still exhibiting ongoing bilateral diaphragmatic paralysis.Case presentationThe patient, a 67-year-old male, presented to the Vascular Surgery Department for surgical treatment of symptomatic Kommerell’s diverticulum in an aberrant right subclavian artery. After successful surgery in two stages, the patient presented with respiratory insufficiency and flaccid tetraparesis consistent with anterior spinal artery syndrome with maintained sensibility of all extremities. A computerized tomography scan (CT) revealed a high-grade origin stenosis of the left vertebral artery, which was treated by angioplasty and balloon-expandable stenting. Consecutively, the tetraparesis immediately resolved, but weaning remained unsuccessful requiring tracheostomy. Abdominal ultrasound revealed a residual bilateral diaphragmatic paralysis. A repeated magnetic resonance imaging (MRI) 14 days after vertebral artery angioplasty confirmed SCI at level C3/C4. The patient was transferred to a pulmonary clinic with weaning center for further recovery.ConclusionsThis novel case highlights the need to consider diaphragmatic paralysis due to SCI as a cause of respiratory failure in patients following aortic surgery. Diaphragmatic paralysis may remain as an isolated residual in these patients.

Ultrasound Diaphragmatic Assessment as a Predictor of Successful Non-Invasive Mechanical Ventilation in Patients with Acute Exacerbation COPD: an Observational Study

Abstract Background Non-invasive ventilation (NIV) is successful as first-line treatment for patients admitted to hospital with hypercapnic respiratory failure due to AECOPD. Significant diaphragmatic muscle dysfunction (DD) exits in different disease-related and physiological conditions, including COPD. Ultrasonography is considered as a non- invasive and bedside method and commonly applied in intensive care unit (ICU) to assess diaphragmatic function. Objective To demonstrate the value of diaphragmatic ultrasound assessment for patients with AECOPD undergoing NIMV. Patients and Methods A population of 24 consecutive patients with AECOPD admitted to Ain Shams University Hospitals’ Intensive Care units (ICU) were enrolled. Change in diaphragmatic thickness fraction (ΔDTF) &amp;lt; 20% and diaphragm excursion&amp;lt; 10 mm during tidal volume was the predefined cut-off for identifying DD. Correlations between ΔDTF &amp;lt; 20%, diaphragm excursion&amp;lt; 10 mm and NIV failure and other clinical outcomes were investigated. Results 24 cases with AECOPD, 33.3% of them (8 cases) had diaphragm dysfunction (DD+) but after NICPAP 2 cases improved and only 6 cases remain with DD and 16 Patients without DD (DD−). DD+ patients had a higher risk for NIV failure than DD−patients (p &amp;lt; 0.011), and this finding was significantly associated with higher in-hospital, and 30-day mortality rates; longer mechanical ventilation duration; higher tracheostomy rate; and longer ICU stay. Conclusion AECOPD patients with diaphragmatic dysfunction as diagnosed by US showed higher incidence of NIMV failure, longer MV, ICU length of stay, In- hospital mortality, ICU and MV duration were significantly longer in group with DD. Insignificant difference was found considering mortality after 30 days in patients with or without diaphragm dysfunction.

Impact of Pressure Targeted Modes of Ventilation on Diaphragmatic Function as Assessed Using Ultrasonography in Critically Ill Patients with Cerebral Insult

Abstract Background Mechanical ventilation (MV) causes diaphragmatic atrophy and reduces diaphragmatic efficiency. Patients with diaphragmatic dysfunction (DD) have longer MV durations and intensive care unit (ICU) stay. There is currently a scarcity of data on the effect of different modes of MV on diaphragmatic function and ultrasound-guided assessment of diaphragmatic efficiency. Methodology Sixty mechanically ventilated patients were randomly divided into four equal groups (15 each), patients were ventilated using either Assist Control Pressure Controlled mode (ACPC group)(Group A), Synchronized Intermittent Mandatory Ventilation Pressure Controlled mode (SIMV)(Group S), Bi-level Positive Airway Pressure mode (BiPAP)(Group B), or Pressure Support Ventilation mode (PSV)(Group P). The primary outcomes were diaphragmatic motion &amp; structure in terms of Diaphragmatic Excursion (DE) &amp; Diaphragmatic Thickness Fraction (DTF) respectively. The duration of the ICU stay was the secondary outcome. Results The PSV group had the highest DE indicating better diaphragmatic function. In addition, MV for longer durations led to diaphragmatic thinning and decreased DTF resulting in DD. Conclusion Among the various modes of ventilation employed in the study, PSV was found to be the mode with the lowest risk of DD. Trial Registry PACTR202112653971335.

Predictive Value of Ultrasonic Diaphragm Thickening Fraction on Successful Weaning in Postoperative Cardiothoracic Surgery Patients with Chronic Obstructive Pulmonary Disease (COPD)

Abstract Background The diaphragm is the most important muscle of respiration and is largely responsible for the change in the intra thoracic pressure. In mechanically ventilated patients, the diaphragm can develop atrophy and weakness leading to prolonged duration of mechanical ventilation. Many studies reported a high prevalence of diaphragm dysfunction during weaning, and it was found to be associated with poorer clinical outcomes. Objective To assess the predictive value of diaphragm thickening fraction (DTF) by bedside ultrasound on successful weaning in postoperative cardiothoracic surgery patients with COPD. Subjects and Methods This prospective study was conducted on 40 subjects at cardiothoracic ICU unit at Elmaadi Military hospital during the period from (September,2021) to (July,2022) after approval of the research Ethical committee at faculty of medicine, Ain shams university. Results Regarding the relation between the two studied groups and diaphragmatic thickness, the thickness was decreased in the failed group than the successful group during inspiration, expiration and thickness fraction %, with significant difference between two groups as p-Value was &amp;lt;0.05. There was an increase in the duration of ICU stay &amp; mechanical ventilation in the failed group compared to the successful group, with significant difference between two groups as p-Value was &amp;lt;0.05. Regarding the correlation between ICU stay &amp; mechanical ventilation and diaphragmatic thickness, there were negative correlation between ICU stay &amp; MV duration and all parameters of the diaphragmatic thickness, with significant difference as p-Value was &amp;lt;0.05. Conclusion Weaning success in mechanically ventilated postoperative cardiothoracic surgery patients with COPD can be predicted by ultrasonography-based evaluation of diaphragm function by analyzing diaphragmatic thickness fraction. It is a practical, feasible, non-invasive technique that may be used at the bedside to rule out diaphragmatic dysfunction.

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

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. 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. 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. 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.

Paradoxical thinning of the diaphragm on ultrasound is a risk factor for requiring non-invasive ventilation in patients with neuromuscular diaphragmatic dysfunction.

Point-of-care ultrasound of the diaphragm is highly sensitive and specific in the detection of neuromuscular diaphragmatic dysfunction. In some patients with neuromuscular diaphragmatic dysfunction, paradoxical thinning of the diaphragm during inspiration is observed on ultrasound; however, its frequency, electrodiagnostic associations, and prognostic significance remain uncertain. Medical records of patients presenting to two electrodiagnostic laboratories (Mayo Clinic, Rochester, Minnesota and University of Alberta, Edmonton, Alberta) from January 1, 2022 to December 31, 2022, for evaluation of suspected neuromuscular respiratory failure, were reviewed. 214 patients were referred and 19 patients excluded due to incomplete information. Of 195 patients (384 hemidiaphragms), 104 had phrenic neuropathy, 12 had myopathy, and 79 had no evidence of neuromuscular disease affecting the diaphragm. Paradoxical thinning occurred in 31 (27%) patients with neuromuscular diaphragmatic dysfunction and was unilateral in 30, the majority (83%) having normal contralateral ultrasound. Phrenic nerve conduction studies and diaphragm electromyography results did not distinguish patients with paradoxical thinning versus without. Most patients (71%) with paradoxical thinning required non-invasive ventilation (NIV), including 16 with unilateral paradoxical thinning. Paradoxical thinning and BMI ≥30 kg/m2 were risk factors for requiring NIV in multivariable logistic regression analysis, with odds ratios of 2.887 (95% CI:1.166, 7.151) and 2.561 (95% CI: 1.186, 5.532), respectively. Paradoxical thinning of the diaphragm occurs in patients with prominent neuromuscular diaphragmatic dysfunction, most commonly from phrenic neuropathy, and is a significant risk factor for requiring NIV. Unilateral paradoxical thinning is sufficient for needing NIV. BMI ≥30 kg/m2 additionally increases risk of requiring NIV in patients with neuromuscular diaphragmatic dysfunction.

CAS3D: 3D quantitative morphometry on Second Harmonic Generation image volumes from single skeletal muscle fibers

The CAS3D image processing method intuitively applies a combination of Fourier space and real space 3D analysis algorithms to volumetric images of single skeletal muscle fiber Myosin II Second Harmonic Generation (SHG) XYZ image data. Our developed tool automatically quantifies the myofibrillar orientation in muscle samples by determining the cosine angle sum of intensity gradients in 3D (CAS3D) while determining the mean sarcomere length (SL) and sample orientation. The expected CAS3D values could be reproduced from ideal artificial data sets. Applied random noise in artificial images lowers the detected CAS3D value, and for noise levels below 20%, the correlation can be approximated by a linear function with a slope of −0.006 CAS3D/noise%. The deviations in SL and orientation detection were determined on ideal and noisy artificial data sets and were statistically indistinguishable from 0 (null hypothesis t-test P > 0.1). The software was applied to a previously published data set of single skeletal muscle fiber volumetric SHG image data from a rat intensive care unit (ICU) model of ventilator-induced diaphragm dysfunction (VIDD) with treatment regimens involving the small anti-inflammatory molecules BGP-15, vamorolone, or prednisolone. Our method reliably reproduced the results of the previous work and improved the standard deviation of the cosine angle sum detection in all sample groups from a mean of 0.03 to 0.008. This improvement is achieved by applying analysis algorithms to the whole volumetric images in 3D in contrast to the previously common method of slice-wise XY analysis.

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.

The ratio of parasternal intercostal muscle-thickening fraction-to-diaphragm thickening fraction for predicting weaning failure

BackgroundDiaphragm dysfunction is associated with weaning outcomes in mechanical ventilation patients, in the case of diaphragm dysfunction, the accessory respiratory muscles would be recruited. The main purpose of this study is to explore the performance of parasternal intercostal muscle thickening fraction in relation to diaphragmatic thickening fraction ratio (TFic1/TFdi2) for predicting weaning outcomes, and compare its accuracy with D-RSBI in predicting weaning failure. Materials and methodsWe prospectively enrolled consecutive patients from 7/2022–5/2023. We measured TFic, TFdi, and diaphragmatic excursion (DE3) by ultrasound and calculated the TFic/TFdi ratio and diaphragmatic rapid shallow breathing index (D-RSBI4). Receiver-operator characteristic (ROC5) curves evaluated the accuracy of the TFic/TFdi ratio and D-RSBI in predicting weaning failure. Results161 were included in the final analysis, 114 patients (70.8%) were successfully weaned from mechanical ventilation. The TFic/TFdi ratio (AUROC = 0.887 (95% CI: 0.821–0.953)) was superior to the D-RSBI (AUROC = 0.875 (95% CI: 0.807–0.944)) for predicting weaning failure. ConclusionsThe TFic/TFdi ratio predicted weaning failure with high accuracy and outperformed the D-RSBI.

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.

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 and Pulmonary Functions Following an Ultrasound-Guided Supraclavicular Approach Versus a Costoclavicular Approach of a Brachial Plexus Block: A Randomized Study.

A costoclavicular brachial plexus block is an emerging infraclavicular approach that targets the cords lateral to the axillary artery, providing rapid onset of sensory-motor blockade. However, the incidence of hemi-diaphragmatic paralysis (HDP), a potential complication, remains unclear compared to the widely used supraclavicular (SC) approach. This study aimed to compare the incidence of HDP between ultrasound-guided costoclavicular and SC brachial plexus blocks. To compare the influence of ultrasound-guided SC and costoclavicular brachial plexus blocks on diaphragmatic excursion, thickness, and contractility along with pulmonary function. This prospective, randomized, observer-blinded controlled trial included 60 patients undergoing below-shoulder surgeries. Patients were randomized to receive either ultrasound-guided SC (Group S) or costoclavicular (Group C) brachial plexus block with 0.5% levobupivacaine. The diaphragmatic function was assessed using ultrasonographic evaluation of diaphragm thickness and diaphragmatic thickness fraction (DTF) pre- and postblock. Pulmonary function tests (PFTs) (forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and peak expiratory flow rate (PEFR)) were performed preblock and two hours postblock. Block characteristics were compared. The SC group exhibited a significantly larger reduction in DTF from preblock to postblock compared to the costoclavicular group (mean ΔDTF: 34.38% vs. 14.01%, p<0.01). Both groups showed significant declines in FVC, FEV1, and PEFR postblock, but the magnitude of deterioration was significantly greater in the SC group, displaying no significant difference in block characteristics. The costoclavicular brachial plexus block demonstrated superior preservation of diaphragmatic contractility and lesser deterioration of PFTs compared to the SC approach while being equally effective. These findings highlight the potential benefits of the costoclavicular technique in minimizing diaphragmatic dysfunction and respiratory impairment, particularly in patients at risk for respiratory complications.

Ultrasound examination in assessing the functional state of the diaphragm in patients with respiratory failure requiring respiratory support

Diaphragm dysfunction (DD) is diagnosed in 60% patients 24 hours after intubation. Diaphragm ultrasound (DU) facilitates non-invasive assessment of excursion and thickness of the diaphragm throughout the breathing cycle. Sonographically measured excursion and thickening fraction (TF) of the diaphragm show moderate correlation with reference methods for diaphragm dysfunction detection. Both increase and decrease in diaphragm thickness in mechanically ventilated patients are associated with prolonged mechanical ventilation. TF exceeding 25% increases probability of successful weaning. Maintaining TF within 15–40 % might shorten the duration of mechanical ventilation.