Lung Volume Research Articles

Assessing the Severity of Connective Tissue-Related Interstitial Lung Disease Using Computed Tomography Quantitative Analysis Parameters

Objectives The aims of the study are to predict lung function impairment in patients with connective tissue disease (CTD)-associated interstitial lung disease (ILD) through computed tomography (CT) quantitative analysis parameters based on CT deep learning model and density threshold method and to assess the severity of the disease in patients with CTD-ILD. Methods We retrospectively collected chest high-resolution CT images and pulmonary function test results from 105 patients with CTD-ILD between January 2021 and December 2023 (patients staged according to the gender-age-physiology [GAP] system), including 46 males and 59 females, with a median age of 64 years. Additionally, we selected 80 healthy controls (HCs) with matched sex and age, who showed no abnormalities in their chest high-resolution CT. Based on our previously developed RDNet analysis model, the proportion of the lung occupied by reticulation, honeycombing, and total interstitial abnormalities in CTD-ILD patients (ILD% = total interstitial abnormal volume/total lung volume) were calculated. Using the Pulmo-3D software with a threshold segmentation method of −260 to −600, the overall interstitial abnormal proportion (AA%) and mean lung density were obtained. The correlations between CT quantitative analysis parameters and pulmonary function indices were evaluated using Spearman or Pearson correlation coefficients. Stepwise multiple linear regression analysis was used to identify the best CT quantitative predictors for different pulmonary function parameters. Independent risk factors for GAP staging were determined using multifactorial logistic regression. The area under the ROC curve (AUC) differentiated between the CTD-ILD groups and HCs, as well as among GAP stages. The Kruskal-Wallis test was used to compare the differences in pulmonary function indices and CT quantitative analysis parameters among CTD-ILD groups. Results Among 105 CTD-ILD patients (58 in GAP I, 36 in GAP II, and 11 in GAP III), results indicated that AA% distinguished between CTD-ILD patients and HCs with the highest AUC value of 0.974 (95% confidence interval: 0.955–0.993). With a threshold set at 9.7%, a sensitivity of 98.7% and a specificity of 89.5% were observed. Both honeycombing and ILD% showed statistically significant correlations with pulmonary function parameters, with honeycombing displaying the highest correlation coefficient with Composite Physiologic Index (CPI, r = 0.612). Multiple linear regression results indicated honeycombing was the best predictor for both the Dlco% and the CPI. Furthermore, multivariable logistic regression analysis identified honeycombing as an independent risk factor for GAP staging. Honeycombing differentiated between GAP I and GAP II + III with the highest AUC value of 0.729 (95% confidence interval: 0.634–0.811). With a threshold set at 8.0%, a sensitivity of 79.3% and a specificity of 57.4% were observed. Significant differences in honeycombing and ILD% were also noted among the disease groups (P < 0.05). Conclusions An AA% of 9.7% was the optimal threshold for differentiating CTD-ILD patients from HCs. Honeycombing can preliminarily predict lung function impairment and was an independent risk factor for GAP staging, offering significant clinical guidance for assessing the severity of the patient's disease.

Peritoneal Catheters Malposition/Dysfunction and Their Approach with Catheterography and Radiologic Manipulation in Peritoneal Dialysis: A Minireview and Case Series

Peritoneal catheter dysfunction is one of the most frequent complications of peritoneal dialysis. The malposition of a peritoneal catheter may cause one- or two-way obstruction with fluid outflow or inflow problems, large residual volumes, and, therefore, reduced ultrafiltration and sometimes abdominal pain. Standard procedures may often fail to solve the dysfunction. Catheterography is an interventional radiologic procedure based on the infusion under aseptic conditions of iodated contrast into the peritoneal catheter, followed by the introduction of a guidewire into the catheter for guidewire manipulation. The available literature about catheterography is quite scarce and mainly based on case reports, case series, and small retrospective studies. In this minireview, we describe the guidewire manipulation techniques explored so far and their pros and cons. In addition, four interesting cases of catheterography performed in our center are also reported. In conclusion, in this minireview, the pros and cons of catheterography have been outpointed. Radiologic manipulation of peritoneal catheters may represent an effective and safe solution for malfunctioning peritoneal catheters and may also be exploited as “bridge therapy” to laparotomy in patients temporarily unsuitable for surgery. The advantages of this procedure are that it does not require long-term hospitalization and allows immediate resume of peritoneal dialysis.

Abstract 4135534: Total and Regional Lung Volumes And Pulmonary Blood Flow In Repaired Tetralogy Of Fallot - Smaller Lungs And A Maldistribution of Flow

Introduction: Many pts with repaired tetralogy of Fallot (rTOF) are left with residual pulmonary regurgitation (PR) and poor exercise performance. Small studies in young children suggest that the total lung volume of rTOF pts are smaller than normal and may contribute to these sequelae. As exercise and cardiac performance are intimately related to lung function, it’s surprising that few rTOF studies have investigated cardiopulmonary interactions. Aims: To determine if regional and total lung volumes in rTOF pts are the same size as normals and if the larger amount of forward blood flow courses to the bigger lung. We hypothesized that this may not be the case. Methods: rTOF patients undergoing clinically indicated cardiac magnetic resonance (CMR) were evaluated for lung volumes using dark blood imaging (figure) and blood flow to the branch pulmonary arteries (bPA) using velocity mapping. Significance < P=0.05. Results: Eleven rTOF patients and 25 normal controls were studied. Total control lung volume was significantly larger than those of rTOF. Regional rTOF right and left lung volumes were smaller than their respective control lung volumes, barely missed statistical significance (table). In 6 rTOF pts with CMR prior to and after pulmonary valve replacement (PVR), lung volumes did not differ between the 2 timepoints (1034 vs 998 cc/m 2 respectively). Only 3/11 (27%) rTOF pts had the higher bPA flow coursing to the higher regional lung. The ratio of right bPA forward flow/right lung volume to left bPA forward flow/left lung volume ranged from 0.72-1.51 (ideal balanced flow to each lung would be 1), implying a maldistribution of flow. Conclusion: rTOF patients have smaller total lung volumes than controls with no change after PVR in our study. In addition, only a small proportion of rTOF patients have the larger amount of flow coursing to the larger lung. The ratio of individual bPA flow to individual lung volume implies a maldistribution of pulmonary flow relative to the respective lung volume. Our findings may have implications for timing of PVR, partially explaining PR and poor exercise performance. Flow limiters placed by cath or surgery may be able to redistribute the appropriate flow to regional lung fields.

The prognostic importance of glioblastoma size and shape

Abstract Purpose Extent of resection, MGMT promoter methylation status, age, functional level, and residual tumor volume are established prognostic factors for overall survival in glioblastoma patients. Preoperative tumor volume has also been investigated, but the results have been inconclusive. We hypothesized that the surface area and the shape were more representative of the tumor’s infiltrative capacities, and thus, the purpose of this study was to assess the prognostic value of tumor size and shape in patients with glioblastoma. Methods In total, 271 patients with primary, unifocal glioblastoma were included from two centers in Norway and Sweden, respectively. All tumors were automatically segmented on preoperative MRI scans and manually validated. Tumor volume was used as a measurement of size, whereas sphericity index and area-to-volume ratio defined the shape complexity of the tumor. Contact surface area of the tumor was considered a measurement of both size and shape. Multivariable Cox proportional hazards models were used to assess the prognostic value of the respective tumor measurements, with previously established prognostic factors as covariates. Results There were no associations between preoperative tumor volume and overall survival. Contact surface area (HR = 1.013, p = 0.002) and sphericity index (HR = 2.223, p = 0.001) were both significant independent prognostic factors for survival in the multivariable Cox models. Contact surface area was also associated with MGMT promoter methylation (p = 0.039) and extent of resection (p = 0.017). Conclusion Tumor shape complexity appears to be an independent prognostic factor in glioblastoma patients and may also be associated with MGMT promoter methylation status and extent of surgical resection.

Chronic airway diseases: a new frontier in interventional pulmonology

As medical science has advanced, the incidence of central airway lesions, traditionally the primary focus of interventional pulmonology, has decreased significantly. However, the large population suffering from chronic airway diseases, coupled with unmet treatment needs and a high demand for new technologies and methods, has greatly driven the innovation and application of interventional respiratory techniques. The development and clinical application of techniques such as lung volume reduction, targeted lung denervation, pulsed electric field technology, bronchial thermoplasty, and regenerative medicine for chronic airway diseases are providing new treatment options. Chronic airway diseases are becoming a new frontier in interventional pulmonology.

Clinical application and challenges of thermal vapor lung volume reduction

There are major clinical challenges in the management of chronic obstructive pulmonary disease (COPD). Recent studies suggest that thermal vapor lung volume reduction may be an important interventional method in the treatment of emphysema phenotype of COPD. In this article, we reviewed and summarized the research and development, the current situation of clinical application, and the clinical challenges of thermal vapor lung volume reduction, to provide further clinical evidence for the standardized application of thermal vapor lung volume reduction.

Application and innovation of bronchoscopic lung volume reduction with endobronchial valve

Bronchoscopic lung volume reduction with endobronchial valve (BLVR-EBV) involves the placement of an endobronchial valve (EBV) in the emphysema area of patients with chronic obstructive pulmonary disease (COPD) via bronchoscopy, resulting in the collapse of the target lung lobe. This procedure has been shown to improve pulmonary function, quality of life, and activity endurance in COPD patients. Strict selection criteria and thorough preoperative evaluation are essential to ensure the success of BLVR-EBV. Due to its excellent postoperative performance, BLVR-EBV has been widely used in the treatment of patients with end-stage COPD, including those with conditions such as pulmonary tuberculosis cavities or those requiring surgical treatment. This paper provided a brief overview of the application and innovation of BLVR-EBV in patient assessment, perioperative management, and postoperative outcomes.

Cigarette Smoking Impairs Cardiorespiratory and Metabolic Response at Peak Incremental Exercise and during Recovery in Young, Physically Active Adults

ABSTRACT Purpose: Cigarette smoking (CS) induces systemic changes that impair cardiorespiratory and muscular function both at rest and during exercise. Although these abnormalities are reported in sedentary, middle-aged smokers (SM) with pulmonary disease, few and controversial studies focused on young, physically active SM at the early stage of smoking history. This study aimed at assessing the impact CS on cardiorespiratory and metabolic response during an incremental test and the subsequent recovery in young, physically active SM without known lung or cardiovascular disease. Methods: After pulmonary function evaluation, 12 SM (age: 22±2 yr; body mass: 75±8 kg; stature: 1.78±0.06 m; 12±4 cigarette/day for 6±2 years; mean±SD) and 12 non-smokers (CTRL; age: 23±1 yr; body mass: 76±8 kg; stature: 1.79±0.08 m) matched for age and exercise habits, underwent an exhaustive incremental step test (25 W/2 min) on a cycle ergometer. Pulmonary O2 uptake (V’O2), expiratory ventilation (V’E), heart rate (f H) responses and lactate concentration were assessed during the test and subsequent recovery. Results: Despite similar static lung volumes, SM reported lower peak expiratory flow (-23%; P = 0.003) and maximal voluntary ventilation (-10%; P = 0.003). At submaximal exercise, no differences in the cardiorespiratory and metabolic were noted between the two groups. However, SM exhibited ventilatory (P < 0.01) and lactate thresholds at lower work rates (P = 0.01). At peak exercise, SM exhibited lower V’O2 (-8%; P = 0.02), mechanical power (-11%; P = 0.02) and V’E (-9%; P = 0.01). During recovery, SM showed longer time constants (τ) in V’O2 (+52%; P = 0.002), V’E (+19%; P = 0.027) and f H (+21%; P = 0.022) and smaller f H at 30 s of recovery (HRR30; -31%; P = 0.032). Conclusions: These results are compatible with an early CS-related impairment of the cardiorespiratory and metabolic function even in young individuals with relatively short smoking history.

NIMG-24. PRECISION GLIOBLASTOMA MANAGEMENT USING MET AND FMISO PET SCANS

Abstract OBJECTIVE Positron Emission Tomography (PET) may be useful in diagnosing glioblastoma, determining resection areas, and evaluating therapeutic efficacy. This study evaluated the usefulness of PET scans using 11C-Methionine (MET) to assess amino acid metabolism and 18F-Fluoromisonidazole (FMISO) to assess hypoxic regions in glioblastoma treatment. METHODS Thirty glioblastoma patients who underwent MET and FMISO PET studies from July 2013 to March 2024 were included. Patients underwent the Stupp regimen post-tumor resection and were treated with temozolomide (TMZ) and bevacizumab (Bev) upon recurrence. PET scans were performed before and after two courses of Bev treatment. Changes in tumor to normal ratio (TNR) for MET, tumor to blood ratio (TBR) for FMISO, and metabolic tumor volume (MTV) for both MET and FMISO were evaluated. Progression-free survival (PFS) and overall survival (OS) were compared based on the rate of change in MTV for MET and FMISO. RESULTS The residual volumes (contrast-enhanced MRI, MET, and FMISO) with a MET removal rate of >90% were 0.08 ml, 0.1 ml, and 0.08 ml, respectively. For FMISO removal rates of >90%, residual volumes were 0.36 ml, 1.54 ml, and 0.05 ml, respectively. Groups with a decreased rate of change in MET MTV had significantly better outcomes: PFS (months) 10.7 vs. 2.8 (p=0.19) and OS (months) 18.6 vs. 4.9 (p=0.09). In the FMISO groups, decreased TBR change rates correlated with better outcomes: PFS (months) 16.6 vs. 2.5 (p<0.01) and OS (months) 22.8 vs. 4.9 (p<0.01). MTV change rates also showed significant differences in outcomes: PFS (months) 10.5 vs. 3.7 (p=0.76) and OS (months) 14.9 vs. 7.0 (p=0.87). CONCLUSION Higher MET removal rates correlate with fewer contrast-enhanced MRI and FMISO accumulation areas, suggesting MET as a reliable tumor removal indicator. Both MET and FMISO PET scans are valuable in determining glioblastoma treatment response.

A Programmatic Approach to En Bloc Transurethral Enucleation of the Prostate with Bipolar System (TUEB): A Single-Center Retrospective Report

Introduction: This study presents a systematic approach for en bloc transurethral enucleation of the prostate utilizing a bipolar system (TUEB), evaluating its effectiveness and safety. Furthermore, the research aims to pinpoint risk factors contributing to early stress urinary incontinence (SUI) after undergoing en bloc TUEB. Methods: The en bloc TUEB procedure is visually demonstrated through images and videos. A retrospective analysis was conducted based on the data of 88 patients diagnosed with benign prostatic hyperplasia (BPH) who underwent en bloc TUEB between January 2018 and April 2023. Detailed perioperative and follow-up clinical data were collected and analyzed. Patients were categorized based on the occurrence of SUI, and their clinical characteristics were analyzed. Results: The mean surgical duration was 113.1 ± 50.0 minutes, resulting in an excised prostate gland weighing 58.0 ± 34.3 g and a hemoglobin drop of 14.3 ± 11.2 g/L. The average enucleation rate was 79.00 ± 11.01 %, enucleation efficiency was 0.54 ± 0.26 g/min and prostate specific antigen (PSA) reduction rate was 42.08 ± 22.85 %. There were no major complications during operation. Twenty-three patients (26.13%) developed early SUI after catheter removal, and 74% of them were in remission within 1 month. Importantly, no cases of persistent SUI were observed. Lower urinary tract symptoms (LUTS) duration was significantly different between patients with and without post-operative SUI. Residual urine volume, International Prostate Symptom Score (IPSS) and Quality of Life (QoL) score were significantly improved in BPH patients after surgery (P < 0.05). Twelve months after surgery, only 2 patients (2.27%) had urethral stricture, although it recovered after transurethral dilation. Conclusions: En bloc TUEB is proven to be effective, practical, efficient and safe with minimal complications. This procedure could be standardized and widely adopted. LUTS duration can predict the risk of early SUI.

NCMP-10. EFFECT OF EXTENT OF RESECTION ON GLIOMA SEIZURE OUTCOMES BASED ON MOLECULAR GROUPS

Abstract INTRODUCTION Increased extent of resection (EOR) is a known predictor of seizure freedom in glioma patients. However, it is unknown how tumor genomic alterations affect EOR-induced seizure control. OBJECTIVE To evaluate the genotype-specific impact of EOR on post-operative seizure control METHODS Records of 553 glioma patients who underwent tumor resection from 2012-2023 were reviewed. All patient tumors were analyzed with next generation sequencing and FISH analysis. The unsupervised machine learning algorithm non-negative matrix factorization (NMF) was used to cluster the genomic data. Clinical variables including extent of resection of contrast enhancing tumor and non-enhancing tumor, temozolomide therapy, and radiation therapy were analyzed using Cox Proportional Hazards models. RESULTS NMF clustering of tumor sequencing data revealed four molecular groups: Group 1 (n=56): CDKN2a loss, EGFR copy number gain or mutation, TERT promoter (TERTp) mutation, and MGMT methylated; Group 2 (n=27): IDH mutation, TP53 mutation, and MGMT methylated; Group 3 (n=60): TP53 mutation, TERTp mutation and MGMT methylated; Group 4 (n=244): MGMT unmethylated. Thresholds in the post-operative residual non-enhancing tumor volume (NETV) were identified which marked the most difference in seizure control. For patients in Group 1, the NETV threshold that led to improved epilepsy outcomes was <94.7 cc (p=0.047), whereas the threshold for Group 4 was <89.1 cc (p=0.016). When analysis was conducted for Group 2, the threshold of 10.2 cc failed to reach significance (p=0.1). Interestingly, the threshold analysis for Group 3 found that having a NETV of > 10.1 cc showed improved seizure outcomes (p=0.016). A multivariable cox proportional hazard analysis found that twelve-month seizure freedom was predictive of better OS in group 1 (HR 0.02, p=0.05) and group 4 (HR 0.21, p=1.63e-9). CONCLUSION Our study reveals clinically distinct molecular groups of glioma that display different seizure responses. This data suggests a tumor-specific approach to aggressiveness of extent of resection in order to achieve optimal seizure control.

SURG-42. THE T1/T2 RATIO IS ASSOCIATED WITH RESECTABILITY IN PATIENTS WITH IDH-MUTANT ASTROCYTOMAS CNS WHO GRADES 2 AND 3

Abstract PURPOSE IDH-mutant astrocytomas CNS WHO grade 2 and 3 show heterogenous appearance on magnetic resonance imaging (MRI). In the pre-molecular era, the discrepancy between T1 hypointense and T2 hyperintense tumor volume in absolute values has been proposed as a marker for diffuse tumor growth. We set out to investigate if a ratio of T1 to T2 tumor volume (T1/T2 ratio) is associated with resectability and overall survival in patients with IDH-mutant astrocytomas. METHODS Patient data from two centers (Center A: Sahlgrenska University Hospital, Gothenburg, Sweden; Center B: LMU University Hospital, Munich, Germany) were collected retrospectively. Inclusion criteria were as follows: pre- and postoperative MRI scans available for volumetric analysis (I), diagnosis of an IDH-mutant astrocytoma between 2003-2021 (II), and tumor resection at initial diagnosis (III). Tumor volumes were manually segmented. The T1/T2 ratio was calculated and correlated with extent of resection, residual T2 tumor volume, and overall survival. RESULTS The study comprised 134 patients with 65 patients included from Center A and 69 patients from Center B. The median overall survival was 134 months and did not differ between the cohorts (p=0.29). Overall, the median T1/T2 ratio was 0.79 (range 0.15-1.0). Tumors displaying a T1/T2 ratio of 0.33 or lower showed significantly larger residual tumor volumes postoperatively (median 17.9 cm3 versus 4.6 cm3, p=0.03). The median extent of resection in these patients was 65% versus 90% (p=0.03). The ratio itself did not correlate with overall survival. In multivariable analyses, larger postoperative tumor volumes were associated with shorter survival times (HR 1.02, 95% CI 1.01-1.03, p<0.01). CONCLUSION The T1/T2 ratio might be a good indicator for diffuse tumor growth on MRI and is associated with resectability in patients with IDH-mutant astrocytoma. This ratio might aid to identify patients in which an oncologically relevant tumor volume reduction cannot be safely achieved.

NIMG-39. THE “RESECTABILITY INDEX” AS A NOVEL OBJECTIVE PREDICTOR OF SURVIVAL FOR PATIENTS WITH ADULT-TYPE DIFFUSE GLIOMAS

Abstract Extent of resection (EOR) is a strong prognostic factor for patients with adult-type diffuse gliomas. Whole brain tractography (WBT) allows visualization of tumors in relation to functional subcortical white matter tracts connecting eloquent cortex. We developed a preoperative metric, the resectability index (RI), to estimate tumor resectability based on pre-resection volume (PRV) and unresectable tumor volume (UTV). We explore if RI predicts progression-free survival (PFS) and overall survival (OS). We retrospectively reviewed the charts of consecutive patients with adult-type diffuse gliomas resected from 2013-2020. Only patients with pre-operative DTI MRIs were included. UTV was the total overlapping volume of tumor with functionally significant tracts (corticospinal, arcuate, optic, fornix) and deep structures (basal ganglia, thalamus, brainstem). RI was (PRV-UTV)/PRV. Seventy-nine patients were included with an average age of 56 years at time of surgery. Glioblastoma was the most common histology (68%). Tumors were located in the left hemisphere (LH) (48%), right hemisphere (RH) (39%), and bilateral hemispheres or midline (BHM) (13%). EOR for LH, RH, and BHM tumors was 0.8, 0.91, and 0.29, respectively (P = 0.1^7). RI for LH, RH, and BHM tumors was 0.86, 0.912, and 0.44, respectively (P = 0.00021). Cox regression was used to model PFS and OS based on age, preoperative KPS, WHO grade, EOR, and RI. Age, recurrent status, bilaterality, residual tumor volume (RTV) and UTV predicted PFS (CI = 1.01 – 1.06, P = 0.002). For OS, UTV and RI were more strongly predictive than RTV or EOR. In a Cox regression model consisting only of preoperative variables, RI was independently predictive of OS. RI is a novel metric with potential efficacy for preoperative survival prognostication in patients with diffuse gliomas. RI may enable neurosurgeons to provide HGG patients with more accurate information about expected benefits of surgical intervention than is currently possible. RI will also enable more valid comparisons of HGG patient cohorts treated at different institutions.

Understanding the link between interstitial lung disease and obstructive sleep apnea: is lung volume involved?

Understanding the link between interstitial lung disease and obstructive sleep apnea: is lung volume involved?

Quando lo shock ipovolemico... è una malattia esantematica

A 9-year-old boy presented with fever, vomiting and respiratory distress. He was diagnosed with left pleural effusion and reduced lung capacity, confirmed by ultrasound and CT. Treatment included rehydration, oxygen and antibiotics. Cultures revealed Streptococcus pyogenes. The case highlights the rise in invasive GAS infections, especially post-COVID-19.

Decreases in lung volume and lung height among ankylosing spondylitis patients with pulmonary function impairment: a 3D CT investigation

BackgroundRespiratory compromise among ankylosing spondylitis (AS) patients is characterized by restrictive pulmonary function, leading to the need for a meticulous assessment of lung volume. Compared with conventional pulmonary function tests (PFTs), CT-based lung volume measurements have superior accuracy and are crucial for understanding functional limitations in AS. This study investigated the correlation between CT lung volume and PFT parameters in AS patients, with a focus on changes in CT parameters and lung volume in patients with compromised pulmonary function.MethodsA total of 79 AS patients were included, and their full-length radiographs, thoracic CT scans, and PFT data were analysed. Specialized software was used to estimate the total and lobar lung volumes from the CT scans. The relationship between lung volume and PFT results was examined, and a multiple linear regression model was constructed to determine the influence of radiographic and CT parameters on total lung volume (TLV). Patients were classified into normal or impaired pulmonary function groups based on PFT outcomes, thus facilitating comparative analyses of radiographic and CT parameters and lung volumes between these groups.ResultsAmong the 79 AS patients, 19 had normal function, 4 had mixed dysfunction, and 56 experienced restrictive dysfunction. PFT parameters, including FVC, FEV1, TLC, FEV1%, and TLC%, showed varying correlations with TLV and individual lobe volume. Patients with compromised pulmonary function exhibited more pronounced spinal kyphosis and experienced a decline in TLV. Multiple regression analysis revealed that lung height and horizontal and vertical lung diameters independently influenced TLV. Notably, a decrease in lung height was observed in patients with impaired pulmonary function, whereas the horizontal and vertical diameters of the lungs remained stable.ConclusionsIn AS patients, TLV was found to be correlated with pulmonary function, particularly parameter such as FVC, FEV1, and TLC. A significant reduction in TLV was observed in those with impaired pulmonary function, with the primary contributing factor being a decrease in lung height.

Manifestations of toxic pulmonary edema during respiratory support in an experiment

BACKGROUND: Currently, respiratory support is successfully used to treat pulmonary edema of non-toxic origin. The manifestations of pulmonary edema of non-toxic origin and toxic pulmonary edema have similar features, so respiratory support can be effective in treating the latter. AIM: To describe the manifestations of toxic pulmonary edema in rabbits and demonstrate the effectiveness of artificial pulmonary ventilation with support of positive end-expiratory pressure (PEEP) in case of severe intoxication with thermal destruction products of fluoroplastic-4. MATERIALS AND METHODS: Three rabbits were used in the study: rabbit N 1 (control), rabbit N 2 (intoxication) and rabbit N 3 (treatment). Rabbits N 2 and 3 were subjected to severe intoxication with thermal destruction products of fluoroplastic-4 (1,5 HLC50, 15 min). For treatment, rabbit N 3 (treatment), an hour after exposure, underwent mechanical ventilation with PEEP (pressure-controlled mode; oxygen fraction — 0,3; starting PEEP — 5 cm H2O, tidal volume — 20–25 ml). At various times, chest radiography was performed, oxygenation index, hemoglobin saturation (SaO2), and partial pressure of carbon dioxide in exhaled air (PetCO2) were determined. Posthumously, pathological changes in lung tissue, pulmonary coefficient were determined, and histological examination was performed. RESULTS: Exposure of rabbit N 2 (intoxication) to the thermal destruction products of fluoroplastic-4 led to the sequential formation of the interstitial and alveolar phases of toxic pulmonary edema, which contributed to its death 13 hours after exposure. As SaO2 decreased and PetCO2 increased (3 and 5 hours after exposure), in rabbit N 3 (treatment), during respiratory support, PEEP was increased twice by 2 cm H2O (maintaining a given respiratory volume), which led to the normalization of the studied parameters. On the 7th day after exposure, the condition of rabbit N 3 (treatment) did not differ from the condition of rabbit N 1 (control); no pathological changes in the respiratory system were detected. CONCLUSION: Carrying out mechanical ventilation with PEEP, started an hour after exposure (with a stepwise increase in PEEP as the condition worsens), is effective for correcting toxic pulmonary edema in rabbits caused by severe intoxication with the thermal destruction products of fluoroplastic-4.

Comparison of enteral prucalopride versus intravenous metoclopramide for feeding intolerance in patients with critical illness: a randomized double-blinded study

BackgroundFeeding intolerance is commonly experienced during enteral feeding, necessitating cessation. Metoclopramide may be given to assist gastric emptying, but patients experience adverse effects and gradual loss of efficacy. Prucalopride, a safer prokinetic, may play a role in gastric emptying. Therefore, the current study aimed to assess its effectiveness and safety in feeding intolerance developed in critically ill patients.Materials and MethodsIn this prospective randomized double-blinded study, patients with feeding intolerance were randomized to receive 2 mg prucalopride enterally once daily or 10 mg metoclopramide intravenously every 6–8 h for 7 days. Patients were monitored for treatment failure, successful feeding, gastric residual volume (GRV), and the development of medication-related adverse effects.ResultsA total of 70 patients (35 in the metoclopramide group and 35 in the prucalopride group) completed the study. The average daily GRV in the prucalopride group was significantly lower compared to the metoclopramide group (p=<0.001) on day 7. Additionally, the percentage change in GRV from day 1 to day 7 showed a greater significant change in the prucalopride arm versus the metoclopramide arm (p=<0.001). The treatment groups were comparable in terms of ICU length of stay (p = 0.094). Moreover, there was a significantly higher successful caloric intake in the prucalopride group compared to the metoclopramide group on day 7 (p = 0.039).ConclusionPrucalopride administration in enterally fed patients with feeding intolerance may reduce GRV and improve feeding success rates compared to metoclopramide treatment. The use of prucalopride was found to be tolerable and safe in critically ill patients.Clinical Trial Registrationclinicaltrials.gov, identifier NCT05496179

Multi-level digital-twin models of pulmonary mechanics: correlation analysis of 3D CT lung volume and 2D Chest motion

Creating multi-level digital-twin models for mechanical ventilation requires a detailed estimation of regional lung volume. An accurate generic map between 2D chest surface motion and 3D regional lung volume could provide improved regionalisation and clinically acceptable estimates localising lung damage. This work investigates the relationship between CT lung volumes and the forced vital capacity (FVC) a surrogate of tidal volume proven linked to 2D chest motion. In particular, a convolutional neural network (CNN) with U-Net architecture is employed to build a lung segmentation model using a benchmark CT scan dataset. An automated thresholding method is proposed for image morphology analysis to improve model performance. Finally, the trained model is applied to an independent CT dataset with FVC measurements for correlation analysis of CT lung volume projection to lung recruitment capacity. Model training results show a clear improvement of lung segmentation performance with the proposed automated thresholding method compared to a typically suggested fixed value selection, achieving accuracy greater than 95% for both training and independent validation sets. The correlation analysis for 160 patients shows a good correlation ofRsquared value of 0.73 between the proposed 2D volume projection and the FVC value, which indicates a larger and denser projection of lung volume relative to a greater FVC value and lung recruitable capacity. The overall results thus validate the potential of using non-contact, non-invasive 2D measures to enable regionalising lung mechanics models to equivalent 3D models with a generic map based on the good correlation. The clinical impact of improved lung mechanics digital twins due to regionalising the lung mechanics and volume to specific lung regions could be very high in managing mechanical ventilation and diagnosing or locating lung injury or dysfunction based on regular monitoring instead of intermittent and invasive lung imaging modalities.

Update of prognosis and characteristics of chronic obstructive pulmonary disease in a real-world setting: a 5-year follow-up analysis of a multi-institutional registry

BackgroundWe conducted a prospective observational study to elucidate the long-term prognosis and management of chronic obstructive pulmonary disease (COPD) in clinical practice in Japan in the mid-2010s.MethodsThis prospective cohort study included 29 facilities. Data from 427 patients clinically diagnosed with COPD, enrolled between September 2013 and April 2016, were analyzed. Interstitial pneumonia was excluded through a central multidisciplinary discussion. Follow-up data were collected for up to 5 years after patient registration.ResultsAt the time of registration, 53 patients clinically diagnosed with COPD did not have airflow limitation (AFL). In the cohort with AFL (n = 374), 232 patients completed a 5-year follow-up, while 49 patients died during the 1576.6 person-years of observation. The mean age was 71.7 years with an overall 5-year survival rate of 85.4%. Stratified by % forced expiratory volume in one second (FEV1), survival rates were 93.6% in the mild and moderate AFL group, 82.5% in the severe AFL group, and 66.1% in the very severe AFL group. The prognosis of the subpopulation without AFL was poor with a 5-year survival of 81.6%. This subpopulation exhibited respiratory symptoms, low vital capacity and total lung capacity, and emphysematous changes.ConclusionsOur study presents the 5-year survival and real-world clinical practice scenario of a prospective cohort of patients clinically diagnosed with COPD in Japan in the mid-2010s. The survival rates of our cohort were numerically better than the Japanese cohort in the 1990s, regardless of the high median age of this cohort. Overall, 12.4% of the patients in this cohort with no AFL at registration exhibited respiratory symptoms and distinct spirometric patterns, and had a poor prognosis.