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.

Modulation of Titin and Contraction-Regulating Proteins in a Rat Model of Heart Failure with Preserved Ejection Fraction: Limb vs. Diaphragmatic Muscle.

Heart failure with preserved ejection fraction (HFpEF) is characterized by biomechanically dysfunctional cardiomyocytes. Underlying cellular changes include perturbed myocardial titin expression and titin hypophosphorylation leading to titin filament stiffening. Beside these well-studied alterations at the cardiomyocyte level, exercise intolerance is another hallmark of HFpEF caused by molecular alterations in skeletal muscle (SKM). Currently, there is a lack of data regarding titin modulation in the SKM of HFpEF. Therefore, the aim of the present study was to analyze molecular alterations in limb SKM (tibialis anterior (TA)) and in the diaphragm (Dia), as a more central SKM, with a focus on titin, titin phosphorylation, and contraction-regulating proteins. This study was performed with muscle tissue, obtained from 32-week old female ZSF-1 rats, an established a HFpEF rat model. Our results showed a hyperphosphorylation of titin in limb SKM, based on enhanced phosphorylation at the PEVK region, which is known to lead to titin filament stiffening. This hyperphosphorylation could be reversed by high-intensity interval training (HIIT). Additionally, a negative correlation occurring between the phosphorylation state of titin and the muscle force in the limb SKM was evident. For the Dia, no alterations in the phosphorylation state of titin could be detected. Supported by data of previous studies, this suggests an exercise effect of the Dia in HFpEF. Regarding the expression of contraction regulating proteins, significant differences between Dia and limb SKM could be detected, supporting muscle atrophy and dysfunction in limb SKM, but not in the Dia. Altogether, these data suggest a correlation between titin stiffening and the appearance of exercise intolerance in HFpEF, as well as a differential regulation between different SKM groups.

Study on Stamping-Bulging Process of Thin-Walled Superalloy Diaphragm for S-Shaped Bellows.

A combined stamping-bulging forming process was proposed to achieve high-precision forming of large-diameter, ultra-thin-walled, superalloy welded S-type corrugated diaphragms. The underlying principle is to enhance the diaphragm's forming accuracy by increasing the plastic deformation region and reducing springback. Using the ABAQUS version 6.14 finite element analysis software, finite element models were constructed for the stamping, hydraulic bulging, and combined stamping-bulging forming processes of the welded S-type metal corrugated diaphragms. A comparative analysis was conducted on the forming processes of the welded S-type metal corrugated diaphragms under the three forming methods, focusing on equivalent stress, distribution of wall thickness, and forming accuracy. This analysis determined the optimal forming process and the corresponding process parameters for superalloy welded S-type metal corrugated diaphragms. The results show that under a constant drawing force, as the bulging pressure increases, the plastic deformation of the straight sections of the diaphragm becomes more pronounced, resulting in improved shape accuracy. The combined stamping-bulging forming process guarantees the highest degree of shape accuracy for the diaphragm. The optimal process parameters were identified as a 30 t force and a 5 MPa pressure, with a maximum shape error of 0.02 mm. Concerning a plate thickness of 0.3 mm, the maximum deviation rate was found to be 6.7%, which represents a 30% improvement over traditional stamping processes. The maximum wall thinning rate was found to be 3.3%, a 1% reduction compared to traditional stamping processes, confirming the process's feasibility.

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

INTRODUCTION/AIMS: 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. METHODS: 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. RESULTS: 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. DISCUSSION: 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.

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.

Nonsteroidal anti-inflammatory drug-induced small bowel strictures (diaphragm disease) - an under-recognized cause of small bowel obstruction.

BACKGROUND: Small bowel obstruction is a major source of morbidity and mortality that carries a significant economic burden. Recurrent small bowel obstruction may be secondary to circumferential strictures (small bowel diaphragm disease), an under-recognized entity secondary to long-term nonsteroidal anti-inflammatory drug (NSAID) use. We aimed to describe the sensitivity of preoperative computed tomography (CT) enterography in patients with surgically treated small bowel diaphragm disease. METHODS: We retrospectively reviewed adult patients who underwent elective small bowel resection for small bowel obstruction performed by a single minimally invasive surgeon between 2010 and 2023. Patient history, radiographic, endoscopic, operative, and pathology reports were reviewed for reference to NSAID use, small bowel strictures, diaphragms, and enteropathy. Exclusion criteria were prior radiation, inflammatory bowel disease, malignancy, adhesive disease, and anastomotic strictures. RESULTS: A total of 225 patients were identified, 22 (10%) of whom met the inclusion criteria. The mean age was 60.7 years (range 29-78), with 15 women (68%). All patients underwent minimally invasive small bowel resection for obstruction with histopathologic evidence of stricture without evidence of transmural inflammation, granuloma, or dysplasia and confirmed NSAID use (n = 22, 100%). Anemia was present in 36% (n = 8). Preoperative CT or magnetic resonance (MR) enterography was performed in 18 patients (82%), of which stricturing was reported in 13 (72%). Intraoperatively, palpation identified strictures in all patients. CONCLUSION: NSAID-induced small bowel injury is an under-recognized condition that, in severe cases, can present as small bowel obstruction. Surgeons should consider diaphragm disease in patients with obstruction and NSAID use, in which preoperative CT or MR enterography may be useful but cannot rule out disease.

Phospholipid scramblase 1: an essential component of the nephrocyte slit diaphragm.

Blood ultrafiltration in nephrons critically depends on specialized intercellular junctions between podocytes, named slit diaphragms (SDs). Here, by studying a homologous structure found in Drosophila nephrocytes, we identify the phospholipid scramblase Scramb1 as an essential component of the SD, uncovering a novel link between membrane dynamics and SD formation. In scramb1 mutants, SDs fail to form. Instead, the SD components Sticks and stones/nephrin, Polychaetoid/ZO-1, and the Src-kinase Src64B/Fyn associate in cortical foci lacking the key SD protein Dumbfounded/NEPH1. Scramb1 interaction with Polychaetoid/ZO-1 and Flotillin2, the presence of essential putative palmitoylation sites and its capacity to oligomerize, suggest a function in promoting SD assembly within lipid raft microdomains. Furthermore, Scramb1 interactors as well as its functional sensitivity to temperature, suggest an active involvement in membrane remodeling processes during SD assembly. Remarkably, putative Ca2+-binding sites in Scramb1 are essential for its activity raising the possibility that Ca2+ signaling may control the assembly of SDs by impacting on Scramb1 activity.

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.

Artificial ascites­assisted microwave ablation for liver cancer adjacent to the diaphragm and perioperative nursing care.

Liver cancer near the deep diaphragm can be difficult to visualize due to the effects of lung gas, which presents a challenge for microwave ablation (MWA). The present study aimed to investigate the feasibility and efficacy of artificial ascites-assisted MWA for treating liver cancer near the deep diaphragm, as well as the significance of perioperative nursing. A retrospective analysis was conducted on patients who underwent artificial ascites-assisted MWA for liver cancer located near the deep diaphragm between January 2016 and December 2022. Normal saline was utilized as artificial ascites to safeguard the deep diaphragm during MWA. The study recorded the procedural success rate, incidence of major complications, technical efficacy of ablation and local tumor progression (LTP). A total of 62 lesions in 54 patients were included, with 44 men and 10 women, and a mean (± SD) age of 55.64±10.33 years. The ultrasound image quality scores for liver cancer before and after ascites were 3.57±0.79 and 4.89±0.33, respectively, showing a statistically significant difference between the two groups (t=16.324; P<0.05). No diaphragm injury, skin burns at the puncture site or abdominal hemorrhage occurred during the procedure. A single patient developed right-sided pleural effusion, which did not require drainage. The complete ablation rate was 94.4% (51/54) at 1 month post-ablation, with 3 patients experiencing recurrence and receiving additional MWA treatment. The median follow-up time for the patients in this study was 21 months (range, 12-45 months), with a LTP rate of 5.6% (3/54). In conclusion, MWA assisted by artificial ascites is a safe and effective treatment for liver cancer near the deep diaphragm. Furthermore, perioperative treatment and rehabilitation of the patients with high-quality nursing is beneficial.

Improvement in respiratory function and exercise tolerance following video-assisted thoracoscopic diaphragm plication for symptomatic iatrogenic persistent diaphragm paralysis after radiofrequency catheter ablation.

Hemidiaphragm paralysis, a complication of catheter ablation for atrial fibrillation, can severely affect respiratory function and can lead to paradoxical breathing and dyspnea on exertion. A 75-year-old woman with iatrogenic diaphragm paralysis showed improved symptoms, respiratory function, and exercise tolerance after video-assisted thoracoscopic diaphragm plication.

Phrenitis and the pathology of the mind in western medical thought (fifth century BCE to twentieth century cE).

Phrenitis is ubiquitous in ancient medicine and philosophy. Galen mentions the disease innumerable times, Patristic authors take it as a favourite allegory of human flaws, and no ancient doctor fails to diagnose it and attempt its cure. Yet the nature of this once famous disease has not been properly understood by scholars. My book provides the first full history of phrenitis. In doing so, it surveys ancient ideas about the interactions between body and soul, both in health and in disease. It also addresses ancient ideas about bodily health, mental soundness and moral 'goodness', and their heritage in contemporary psychiatry, offering a chance to reflect critically on contemporary ideas about what it means to be 'insane'.

Chronic N-acetyl cysteine treatment does not improve respiratory system performance in the mdx mouse model of Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is characterised by respiratory muscle injury, inflammation, fibrosis and weakness, ultimately culminating in respiratory failure. The dystrophin-deficient mouse model of DMD (mdx) shows evidence of respiratory muscle remodelling and dysfunction contributing to impaired respiratory system performance. The antioxidant N-acetylcysteine (NAC) has been shown to exert anti-inflammatory and anti-fibrotic effects leading to improved respiratory muscle performance in a range of animal models of muscle dysfunction, including mdx mice, following short-term administration (2 weeks). We sought to build on previous work by exploring the effects of chronic NAC administration (3 months) on respiratory system performance in mdx mice. One-month-old male mdx mice were randomised to receive normal drinking water (n = 30) or 1% NAC in the drinking water (n = 30) for 3 months. At 4 months of age, we assessed breathing in conscious mice by plethysmography followed by ex vivo assessment of diaphragm force-generating capacity. Additionally, diaphragm histology was performed. In separate studies, in anaesthetised mice, respiratory electromyogram (EMG) activity and inspiratory pressure across a range of behaviours were determined, including assessment of peak inspiratory pressure-generating capacity. NAC treatment did not affect force-generating capacity of the mdx diaphragm. Collagen content and immune cell infiltration were unchanged in mdx + NAC compared with mdx diaphragms. Additionally, there was no significant effect of NAC on breathing, ventilatory responsiveness, inspiratory EMG activity or inspiratory pressure across the range of behaviours from basal conditions to peak system performance. We conclude that chronic NAC treatment has no apparent beneficial effects on respiratory system performance in the mdx mouse model of DMD suggesting limited potential of NAC treatment alone for human DMD.

Transabdominal Minimally Invasive Repair of a Left Chronic Traumatic Diaphragmatic Hernia.

Although the exact incidence of traumatic diaphragmatic hernia (TDH) is unknown, it can carry significant morbidity if not treated promptly. TDH is thought to be more common in penetrating thoracoabdominal trauma compared to blunt trauma. The left side is thought to be more commonly affected than the right due to the protective effects of the liver on the right hemidiaphragm in trauma. Although large defects are evident on CT imaging and the detection rate is improved with higher resolution CT scanners, smaller ruptures may require laparoscopy for definitive diagnosis if there is a high index of suspicion. In this case report, we present a case of a missed left TDH on CT imaging, with eventual herniation of the omentum and stomach. Although TDH traditionally is approached via thoracotomy or laparotomy, we demonstrate that a transabdominal minimally invasive approach with robot-assisted laparoscopic repair is a viable option, with the potential to reduce the morbidities associated with the open approach.

Open left diaphragm method enables safe surgery with a good visual field in a laparoscopic transhiatal approach for esophagogastric junction adenocarcinoma laparoscopic transhiatal reconstruction via an open left diaphragm method.

BACKGROUND: Despite being oncologically acceptable for esophagogastric junction adenocarcinoma with an esophageal invasion length of 3-4 cm, the transhiatal approach has not yet become a standard method given the difficulty of reconstruction in a narrow space and the risk of severe anastomotic leakage. This study aimed to clarify the safety and feasibility of the open left diaphragm method during the transhiatal approach for esophagogastric junction adenocarcinoma. METHODS: This retrospective study compared the clinical outcomes of patients who underwent proximal or total gastrectomy with lower esophagectomy for Siewert type II/III adenocarcinomas with esophageal invasion via the laparoscopic transhiatal approach with or without the open left diaphragm method from April 2013 to December 2021. RESULTS: Overall, 42 and 13 patients did and did not undergo surgery with the open left diaphragm method, respectively. The median operative time was only slightly shorter in the open left diaphragm group than in the non-open left diaphragm group (369 vs. 482 min; P = 0.07). Grade ≥ II postoperative respiratory complications were significantly less common in the open left diaphragm group than in the non-open left diaphragm group (17% vs. 46%, P = 0.03). Neither group had grade ≥ IV anastomotic leakage, and two cases of anastomotic leakage requiring reoperation were drained using the left diaphragmatic release technique. CONCLUSIONS: Transhiatal lower esophagectomy with gastrectomy using the open left diaphragm method is safe, highlighting its advantages for Siewert type II/III esophagogastric junction adenocarcinoma with an esophageal invasion length of ≤ 4 cm.

Analysis of Hemorrhagic Shock Following Percutaneous Nephrolithotomy Resulting from Diaphragm Injury: A Case Report.

BACKGROUND: Percutaneous nephrolithotomy (PCNL) is the first treatment for complex renal and/or ureteral calculi. This paper presents a case of hemorrhagic shock resulting from diaphragm injury due to PCNL, which has not been reported so far. CASE PRESENTATION: A 55-year-old Asian woman presented with a 2 × 2 cm calculus located in the upper calyx of the right kidney. After her uncomplicated PCNL operation, the patient's blood pressure decreased to less than 90/60 mmHg, and her hemoglobin level dropped from 128 g/L to 76 g/L. Physical examination and bedside ultrasound indicated a small amount of pleural effusion. Subsequently, a diagnostic puncture of the chest cavity was performed and revealed the presence of fresh blood. Therefore, thoracic closed drainage was conducted, and 950 mL of fresh blood was drained through a drainage tube. Intraoperatively, observation showed that the nephrostomy tube had penetrated the kidney through the diaphragm. The nephrostomy tube was subsequently removed, and the diaphragm was repaired. CONCLUSIONS: Hemorrhagic shock due to diaphragm injury is an unusual complication after PCNL. This complication should be considered if pleural effusion is present and if blood pressure progressively drops with no other obvious explanation. The recommended treatments include diagnostic thoracentesis and thoracic exploration.

Diaphragm reconstruction using a TachoSil patch as alternative to intrasellar packing for small focal diaphragm defects in pituitary surgery: a cohort study.

BACKGROUND: During pituitary surgery, CSF leaks are often treated by intrasellar packing, using muscle or fat grafts. However, this strategy may interfere with the interpretation of postoperative MRI and may impact the quality of resection in cases of second surgery, due to the existence of additional fibrous tissue. We present an alternative technique, using a diaphragm reconstruction with a heterologous sponge combining fibrinogen and thrombin (TachoSil), applied in selected patients with low-flow CSF leaks. This study investigates the surgical outcome of patients treated with this strategy. METHODS: From a cohort of 2231 patients treated from June 2011 to June 2023 by endoscopic endonasal approach for pituitary surgery, the surgical technique of diaphragm repair with TachoSil patch performed in 55 patients (2.6%) was detailed, and the rate of closure failure was analyzed at 6 months postoperatively. No intrasellar packing was used and sellar floor reconstruction was performed whenever possible. The rate of postoperative CSF leak was compared with that reported in three previous publications that also used the TachoSil patch technique. RESULTS: Patients were mostly women (F/M ratio: 1.2) with a median age of 53.6 years. Surgery was indicated for non-functioning adenomas, Cushing's disease, acromegaly, and Rathke's cleft cysts in 38/55 (69.1%), 6/55 (10.9%), 5/55 (9.1%) and 6/55 (10.9%) patients respectively. The rate of postoperative CSF leak was 1.8% (n = 1/55), which was not significantly different from that reported in the three cohorts from the literature (2.8%, p > 0.05). No postoperative meningitis was recorded. CONCLUSIONS: In highly selected patients with low-flow CSF leaks related to small focal diaphragm defects, diaphragm reconstruction using a TachoSil patch can be a safe and valuable alternative to intrasellar packing.

Diagnosis of hemidiaphragm paralysis: refine ultrasound criteria.

Background: Ultrasound has demonstrated its interest in the analysis of diaphragm function in patients with respiratory failure. The criteria used to diagnose hemidiaphragm paralysis are not well defined. Methods: The aim of this observational retrospective study was to describe the ultrasound findings in 103 patients with diaphragm paralysis, previously diagnosed by conventional methods after various circumstances such as trauma or surgery. The ultrasound study included the recording of excursions of both diaphragmatic domes and the measurement of inspiratory thickening. Results: On paralyzed hemidiaphragm, thickening was less than 20% in all patients during deep inspiration. Thinning was recorded in 53% of cases. In some cases, the recording of the thickening could be difficult. The study of motion during voluntary sniffing reported a paradoxical excursion in all but one patient. During quiet breathing, an absence of movement or a paradoxical displacement was observed. During deep inspiration, a paradoxical motion at the beginning of inspiration followed by a reestablishment of movement in the cranio-caudal direction was seen in 82% of cases. In some patients, there was a lack of movement followed, after an average delay of 0.4 s, by a cranio-caudal excursion. Finally, in 4 patients no displacement was recorded. Evidence of hyperactivity (increased inspiratory thickening and excursion) of contralateral non-paralyzed hemidiaphragm was observed. Conclusion: To accurately detect hemidiaphragm paralysis, it would be interesting to combine the ultrasound study of diaphragm excursion and thickening. The different profiles reported by our study must be known to avoid misinterpretation.

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

BACKGROUND: Diaphragm 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 METHODS: We 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. RESULTS: 161 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. CONCLUSIONS: The TFic/TFdi ratio predicted weaning failure with high accuracy and outperformed the D-RSBI.