Lung Volume Research Articles

Reduced lung function during childhood in identical twins with discordant fetal growth: a cohort study

Fetal growth restriction (FGR) can negatively affect lung development, leading to increased respiratory morbidity and reduced lung function later in life. Studies regarding the impact of FGR on lung function in singletons are influenced by genetic, obstetric, and maternal factors. To overcome these confounding factors, we aim to investigate lung function in identical twins with selective FGR (sFGR). Lung function assessments were performed in identical twins with sFGR born in our centre between March 1, 2002, and December 31, 2017, aged between 5 and 17 years. sFGR was defined as birthweight discordance ≥20%. Outcome measures consisted of forced expiratory volume in 1s (FEV1), forced vital capacity (FVC), and transfer factor for carbon monoxide (DLCO) and were compared between the smaller and larger twin. Thirty-nine twin pairs performed spirometry of sufficient quality. Median gestational age at birth was 34.3 (interquartile range (IQR) 32.1-36.0) weeks with median birthweights of 1500 (IQR 1160-1880) grams and 2178 (IQR 1675-2720) grams for the smaller and larger twin, respectively. Smaller twins had significantly lower z-scores for FEV1 (-0.94 versus-0.41, p=0.0015), FVC (-0.56 versus-0.06, p<0.0001) and DLCO (-0.50 versus 0.00, p<0.0001) compared to larger co-twins. Although being genetically identical, sFGR in identical twins is associated with a reduction in static and dynamic lung volume and a reduction in lung diffusion, even when taking the reduced lung volume into account. This indicates that adverse growth conditions in utero negatively affect lung development and function, potentially contributing to an increase in respiratory morbidities later in life. The Dutch Heart Foundation and The Bontius Foundation.

The impact of reducing the frequency of gastric residual volume monitoring on nutritional adequacy in critically ill patients

The impact of reducing the frequency of gastric residual volume monitoring on nutritional adequacy in critically ill patients

Brine Valorisation Using Mechanical Vapor Compression Desalination: Approaches to Consider.

Water scarcity is one of the biggest challenges we are facing due to climate change: lack of rainfall and polluted water sources are an increasing reality worldwide. Sustainable Development Goals reinforce the urgency of dealing with this issue, targeting scientific community’s efforts towards solutions for this trending topic, where desalination of seawater is one of the main proposals. However, concerns regarding to the environmental effects of residual brines, generated in the desalination process, are emerging on the spots where this technology has been applied.To contribute to the implementation of desalination technologies, the valorisation of these residual brines brings the opportunity not only to reduce the volume of wastewater generated, but increasing its final concentrations and producing more freshwater from a residue. Nevertheless, it comes with the cost of higher energy demands than in the previous stage: the higher the concentration of the fluid, the higher its energy consumption. We can approach this challenge from two different perspectives, focusing on the final amount of concentrated residue or focusing on the energy demand of the installation.While focusing on reducing the volume of residue to its minimum expression is the most attractive option for concentrating the dissolved salts, it comes with the cost of excessive energy demands. On the other hand, focusing on reducing the power consumption of the installation allows the usage of variable renewables, in a more efficient way, allowing the carbon neutrality of emissions during its operation but obtaining a lower concentrated residue. By using a computational model of the installation, we can replicate its operation and compare results from both perspectives.In this paper we will use two scenarios with fixed conditions for a basic mechanical vapor compression (MVC) desalination plant modelled in TRNSYS, where we can observe the correlations between the final volume of residual brine and the energy consumption required for achieving those results. One of the scenarios will show the biggest final concentration, while the other one will consider the minimum operating conditions for the desalination plant. Apart from those results, there will be an analysis of environmental and economic advantages that can be achieved by the implementation of this technology, as well as an early approach towards the technical aspects involving the development of the model used for these calculations.

Design of the multicentre randomised controlled BENTO trial to demonstrate patient-relevant benefit of bronchoscopic lung volume reduction using thermal vapour ablation in the German healthcare system for patients with upper lobe emphysema: a study protocol

IntroductionApplication of vapour ablation as a novel approach to lung volume reduction has positive effects in patients with severe emphysema. The BENTO study is a randomised, controlled, open, multicentre trial,...

Longitudinal changes in the volume of residual lung lobes after lobectomy for lung cancer: a retrospective cohort study.

It is unclear how the residual lobe volume changes over time after lobectomy. This study aims to clarify the temporal patterns of volume changes in each remaining lung lobe post-lobectomy. A retrospective review was conducted on patients who underwent lobectomy for lung cancer at Yueyang Central Hospital from January to December 2021. Lung CT images were reconstructed in three dimensions to calculate the volumes of each lung lobe preoperatively and at 1, 6, and 12months postoperatively. A total of 182 patients were included. Postoperatively, the median total lung volume change rates relative to preoperative values were -20.1%, -9.3%, and -5.9% at 1, 6, and 12months, respectively. Except for the right middle lobe in patients who underwent right upper lobectomy, the volumes of individual lung lobes exceeded preoperative values. The volume growth of the lung on the side of the resection was significantly more than that of the lung on the opposite side. For left lobectomy patients, the right lower lobe's volume change rate exceeded that of the right upper and middle lobes. Among right lobectomy patients, the left lower lobe and the relatively inferior lobe of right lung had higher volume change rates than the superior one. Right middle lobe change rate was more in patients with right lower lobectomy than right upper lobectomy. Six months postoperatively, FEV1% and right middle lobectomy were positively correlated with the overall volume change rate. One year postoperatively, only age was negatively correlated with the overall volume change rate. 75 patients had pulmonary function tests. Postoperative FEV1 change linearly correlated with 1-year lung volume change rate, but not with theoretical total lung volume change rate or segmental method calculated FEV1 change. Time-dependent compensatory volume changes occur in remaining lung lobe post-lobectomy, with stronger compensation observed in the relatively inferior lobe compared to the superior one(s). Preoperative lung function and age may affect compensation level.

Structured reporting in fetal magnetic resonance imaging with congenital diaphragmatic hernia.

We aim to provide a template structured report of fetal Magnetic Resonance Imaging in congenital diaphragmatic hernia (CDH) that was locally validated by the CDH study group in Mannheim. A selection of 50 fetal MRIs of patients with an isolated diaphragmatic hernia and associated radiology reports from five different senior radiologists from a single center resulted in a primary structured report, which was put into practice by using dedicated software. A questionnaire survey of the interdisciplinary CDH study group Mannheim was used to adapt the report to the clinical requirements. There was a huge variability in how deep the free text reports go into detail. The side of the hernia was named in 94% of cases. In 58%, both the lung volume and the total lung volume were reported. A comparison with the expected lung volume was reported in 66% of cases. Additional findings, such as herniated organs, were reported in 96% of cases. Overall satisfaction with the newly established structured report was high within the CDH study group with a mean of 4.7. The use of the structured report of this study can optimize the interdisciplinary dialog, the standardization of report content, increase report completeness and improve quality.

Comparison of current to past outcomes in congenital diaphragmatic hernia using mri observed-to-expected total fetal lung volume.

Fetal Centers use imaging studies to predict congenital diaphragmatic hernia (CDH) prognosis and the need for fetal therapy. Given improving CDH survival, we hypothesized that current fetal imaging severity predictions no longer reflect true outcomes and fail to justify the risks of fetal therapy. We analyzed our single-center contemporary data in a left-sided CDH cohort (n = 58) by prognostic criteria determined by MRI observed-to-expected total fetal lung volumes: severe <25%, moderate 25-35%, and mild >35%. We compared contemporary survival to prior studies and the TOTAL trials. Contemporary survival was significantly higher than past studies for all prognostic classifications (mild 100% vs 80-94%, moderate 95% vs 59-75%, severe 79% vs 13-25%; P < 0.01), and to either control or fetal therapy arms of the TOTAL trials. Current fetal imaging criteria are overly pessimistic and may lead to unwarranted fetal intervention. Fetal therapies remain experimental. Future studies will require updated prognostic criteria.

Lower urinary tract dysfunction in the central nervous system neurogenic bladder and the real-life treatment outcome of botulinum toxin A

ABSTRACT Neurogenic lower urinary tract dysfunction (NLUTD) is common in patients with central nervous system (CNS) lesions. Cases of cerebrovascular accidents (CVA), Parkinson’s disease, dementia, and other intracranial lesions develop poor bladder control with or without urinary difficulty due to loss of cortical perception of bladder filling sensation and poor coordination of urethral sphincter relaxation during reflex micturition. Patients with CNS lesions usually have overactive bladder (OAB) symptoms, including urgency, frequency, incontinence, voiding symptoms of dysuria, large postvoid residual volume, and retention. In elderly patients with severe CNS disease the OAB symptoms are usually difficult to adequately relieve by medical treatment, and thus, their quality of life is greatly. Botulinum toxin A (BoNT-A) is currently licensed and has been applied in patients with idiopathic and neurogenic OAB due to spinal cord injury or multiple sclerosis. However, the application of BoNT-A in the treatment of urinary incontinence due to NLUTD in chronic CNS lesions has not been well-documented. Although cohort studies and case series support BoNT-A treatment for neurogenic OAB, chronic urine retention after intravesical BoNT-A injection for OAB and exacerbated urinary incontinence after urethral BoNT-A injection for voiding dysfunction have greatly limited its application among patients with NLUTD due to CNS lesions. This article reviews the pathophysiology and clinical characteristics of NLUTD in patients with CNS lesions and the clinical effects and adverse events of BoNT-A injection for patients with NLUTD. A flowchart was created to outline the patient selection and treatment strategy for neurogenic OAB.

#201 Bedside lung ultrasound and bioimpedance spectroscopy for assessment of volume status in chronic kidney disease patients on hemodialysis

Abstract Background and Aims Fluid balance is important in patients with chronic kidney disease undergoing hemodialysis (HD). Majority of HD treatment incorporate a prescription for fluid removal targeted to patient's dry weight. Overestimation of dry weight causes hypertension, left ventricular hypertrophy and heart failure, while underestimation is responsible for chronic dehydration leading to the risk of hypotension. Both complications have a significant impact on the overall morbidity and mortality. Dry weight of the patient is usually assessed by using clinical parameters (edema, BP, JVP etc.), Biochemical parameters (BNP, ANP), Bioimpedance Spectroscopy (BIS) or IVC diameter and collapsibility on ultrasound (VCI index). The use of chest ultrasound to detect lung water has recently received growing attention in clinical research. Ultrasonographic lung comets (counting B-lines artifact) evaluate extravascular lung water and hence is considered as a useful tool to evaluate the hydration status of hemodialysis patients. This study aims to compare the efficacy of body fluid volume status and lung water assessment by clinical methods, Ultrasound chest and Bioimpedance Spectroscopy in chronic kidney disease patients on hemodialysis. Method A cross-sectional study was conducted over a period of 6 months. Dry weight of the patient was assessed by the attending nephrologist based on clinical criteria such as: weight, blood pressure, presence of edema or vascular congestion. A Longitudinal Ultrasound scan of the chest was performed using MicroMaxx Ultrasound System with patient in supine position from second to fourth intercostal space of left hemi-thorax and second to fifth intercostal space of right hemi-thorax along parasternal, midclavicular, anterior axillary and midaxillary lines of each side in a total of 28 sectors. B-lines were defined as hyperechogenic linear artifact emerging from the pleural line, up to the bottom of the screen. Pre and Post dialysis comet score was determined by calculating the total B-lines in each sector. Bioimpedance spectroscopy using Bodystat QuadScan 4000 was performed. Pre and post dialysis total body water (TBW), intracellular water (ICW), extracellular water (ECW) and residual fluid overload (ECW pre HD- ECW post HD) were recorded. Results We conducted 100 assessments on 34 patients presenting to the hospital for maintenance hemodialysis. The mean age of the study population was 54.3 + 11 years with a sex ratio (M/F) of 6:1. Mean systolic blood pressure was 141.1 + 19 mmHg and diastolic blood pressure was 83 + 9.3 mmHg with 3 episodes of intradialytic hypotension. The mean dry weight was 59.8 + 10 Kg and weight gain by clinical assessment was 2.1 + 1.5 Kg. Comet score assessed by ultrasound chest had a mean of 4.54 + 2.53 before dialysis and 1.73 ± 1.36 after dialysis. Residual fluid overload on Bio impedance spectroscopy was 1.11 ± 0.85 litre. The residual fluid overload on Bio impedance spectroscopy and lung ultrasound comet score after dialysis had a significant correlation (p value &amp;lt;0.0001). Of the 100 assessments, 40% had fluid overload after dialysis on Bio impedance and 35% had lung congestion on ultrasound chest even after achieving euvolemia according to the dry weight assessed clinically. Conclusion Lung comets on ultrasound chest and residual volume on bio impedance spectroscopy may precede the development of clinical sign and symptoms in a patient. Therefore, these methods are superior to clinical volume status assessment in chronic kidney disease patients on hemodialysis.

Fabrication and in vitro biological performance of a double-layered nanoparticles-microarc oxidation composite coating on titanium for dental implant application

Abstract Sufficient residual alveolar bone volume plays an important role in the success rate and service life of dental implants. However, alveolar bone deficiency is a common clinical phenomenon, and the alveolar bone would be further absorbed by peri-implant infection. Therefore, it is highly desirable to promote peri-implant alveolar bone regeneration and inhibit alveolar bone resorption when the alveolar bone mass is insufficient. For this purpose, a pH-sensitive double-layered nanoparticles-microarc oxidation (MAO) composite coating was fabricated on titanium for dental implant application in this study. The pH-sensitive double-layered nanoparticles were prepared by a poly(L-lactic acid) inner layer and a chitosan outer shell, containing stromal cell derived factor 1, recombinant human bone morphogenetic protein 2 and osteoprotegerin. The composite coating was fabricated on MAO coating by cross-linking the pH-sensitive double-layered nanoparticles with gelatin. The surface morphology of the composite coating showed that the pH-sensitive double-layered nanoparticles were well distributed and tightly cross-linked in the pores of MAO coating. The composite coating could sustain release the three drugs for more than 30 days. With decreasing pH, the release of osteoprotegerin from the composite coating increased (p&lt;0.05). In vitro biological studies suggested that the composite coating exhibited no cytotoxicity, and can recruit bone marrow-derived mesenchymal stem cells (BMSCs), promote BMSC differentiation into osteoblasts, and inhibit osteoclast generation. Moreover, with decreasing pH, the inhibitory effect on osteoclast generation was enhanced (p&lt;0.05). It can be concluded that the fabricated composite coating, which can promote bone regeneration and inhibit bone resorption, has the potential to be applied on the surface of dental implant, especially when the residual alveolar bone is in poor condition.

#1112 A simplified lung ultrasound guided management protocol of pulmonary congestion in hemodialysis

Abstract Background and Aims Pulmonary congestion PC is frequent in Hemodialysis HD and holds a negative prognostic value. Lung ultrasound LUS is accurate in detecting and quantification PC, however, there are many methods to use LUS to evaluate PC. Here we validate a simplified LUS guided pulmonary congestion management protocol in HD patients that can be easily integrated in clinical practice, while studying at the same time the impact of such method on blood pressure control. Methods A prospective randomized multi-centric trial including stable HD patients in 3 countries. Patients were randomized into two groups: active and control group. All patients had a bedside LUS at the end of their mid-week session every two weeks according to the following time-line: Day 1, 15, 30, 45, 60. Lung ultrasound was performed according to the 8-zone method, and a B line score BLS was obtained. A global BLS of more than 6 was considered reflecting a significant PC level. The dry weight was adapted according to the standard of care in the control group. In the active group, in addition to the standard of care, if BLS was more than 6 at day 1 then the dry weight was reduced by 500 g. The same procedure was repeated at Day 15. (The maximum global dry weight modification per patient was 1 kg) (Fig. 1). Home blood pressure monitoring HBPM was also obtained weekly all through the study period. Results 28 stable HD patients (21 males) were enrolled in the study up until now. Mean age was 66.4 years, 14 were diabetics, 4 with stable ischemic heart disease, 1 heart failure and 27 were suffering from hypertension. Mean dialysis vintage was 35.8 months, and mean residual urine volume was 548 ml/24H. Mean session time was 4 hours. Main study population characteristics are described in Table 1. In the active group, mean BLS at day 1 (13.5) was significantly reduced, and reached (7.57) at day 60. (P &amp;lt; 0.001, ES:1.55) (Fig. 2). This was in parallel with a little but significant reduction in the dry weight (P: 0.03, ES: 0.6) but without a statistically greater UF values (P: 0.23) (Table 2). A significant reduction in home blood pressure was also observed by the HBPM readings, especially in the diastolic BP (P: 0.004). In the control group, the mean BLS at day 1 was (12.1). This level did not change all through the study time line, as it was (12.1) at day 60. No significant difference was observed in the dry weight, or ultrafiltration rate UF or home blood pressure values (Table 3). Conclusion Our simplified LUS guided management protocol was able to safely reduce the pulmonary congestion in HD patients in addition to better controlling their blood pressure. This protocol can be applied easily in every HD unit, and may be added to the standard of care to better estimate the dry weight in HD patients.

Timing of magnetic resonance imaging in pregnancy for outcome prediction in congenital diaphragmatic hernia.

To evaluate the impact of the timing of MRI on the prediction of survival and morbidity in patients with CDH, and whether serial measurements have a beneficial value. This retrospective cohort study was conducted in two perinatal centers, in Germany and Italy. It included 354 patients with isolated CDH having at least one fetal MRI. The severity was assessed with the observed-to-expected total fetal lung volume (o/e TFLV) measured by two experienced double-blinded operators. The cohort was divided into three groups according to the gestational age (GA) at which the MRI was performed (< 27, 27-32, and > 32weeks' gestation [WG]). The accuracy for the prediction of survival at discharge and morbidity was analyzed with receiver operating characteristic (ROC) curves. Multiple logistic regression analyses and propensity score matching examined the population for balance. The effect of repeated MRI was evaluated in ninety-seven cases. There were no significant differences in the prediction of survival when the o/e TFLV was measured before 27, between 27 and 32, and after 32 WG (area under the curve [AUC]: 0.77, 0.79, and 0.77, respectively). After adjustment for confounding factors, it was seen, that GA at MRI was not associated with survival at discharge, but the risk of mortality was higher with an intrathoracic liver position (adjusted odds ratio [aOR]: 0.30, 95% confidence interval [95%CI] 0.12-0.78), lower GA at birth (aOR 1.48, 95%CI 1.24-1.78) and lower o/e TFLV (aOR 1.13, 95%CI 1.06-1.20). ROC curves showed comparable prediction accuracy for the different timepoints in pregnancy for pulmonary hypertension, the need of extracorporeal membrane oxygenation, and feeding aids. Serial measurements revealed no difference in change rate of the o/e TFLV according to survival. The timing of MRI does not affect the prediction of survival rate or morbidity as the o/e TFLV does not change during pregnancy. Clinicians could choose any gestational age starting mid second trimester for the assessment of severity and counseling.

The effect of medium-tension bandage and stump stocking on residual limb maturation in earthquake survivors.

Residual limb maturation is a crucial stage in postamputation care. It was aimed to examine the effect of medium tension bandages and stump stockings on postamputation stump maturation in patients who underwent lower extremity amputations. In this prospective observational study, patients who were earthquake survivors and had undergone emergency amputation of their lower extremities were included. Medium-tension elastic bandage or personalized stump stockings were used for stump maturation. Residual limb volume was measured once a week for 3 weeks. The study included 23 patients and 29 amputated limbs. Because of the larger stump volume of transfemoral amputations and the higher number of these patients in the stocking group (p < 0.001), the stump volume differed across groups before and during the follow-up (p < 0.001). There was no difference in mean volumetric measurement between the bandage and stocking groups over time (p = 0.272). Although the group interaction was significant (p < 0.001), the group × time interaction was not (p = 0.306). Medium-tension bandages and stump stockings had a similar effect on postamputation stump maturation in patients with lower extremity amputations. So, depending on the patient's and physician's preferences, both procedures can be used for stump maturation.

FITNESS LEVEL OF SECONDARY SCHOOL STUDENTS ENGAGED IN SPORTS

School physical education is effective means of providing children with the knowledge for lifelong physical activity. The research was aimed to examine the influence of different sports activities (badminton, basketball, football) on fitness level of boys aged 10-11. 72 boys aged 10-11 were engaged in the research. Evaluation of children’s fitness level involved anthropometric parameters of body length (cm); body mass (kg); hand dynamometry (kg). Cardiovascular and respiratory systems were also assessed: heart rate (HR, bpm) – method of palpation; blood pressure – systolic (SBP, mm Hg) and diastolic (DBP, mm Hg) – method of Korotkoff sounds; vital capacity of lungs (VC, L) – spirometer measuring. The Ruffier index, life index, strength index, the Robinson index and the Quetelet index were considered as well. Summing the points of five parameters, fitness levels were defined as low, below average, average, above average, and high. Comparative analysis of ball games influence on children’s fitness level revealed the highest growth rate among badminton players, though their initial and final parameters were the lowest ones. Research findings made it possible to conclude that extramural engagement in ball games throughout school year had beneficial effect on fitness levels of boys aged 10-11.

Impact of neonatal noninvasive resuscitation strategies on lung mechanics, tracheal pressure, and tidal volume in preterm lambs.

This study investigated the relationship between three respiratory support approaches on lung volume recruitment during the first two hours of postnatal life in preterm lambs. We estimated changes in lung aeration, measuring respiratory resistance and reactance by oscillometry at 5 Hz. We also measured intratracheal pressure in subsets of lambs. The first main finding is that sustained inflation (SI) applied noninvasively (Mask SI; n=7) or invasively (endotracheal tube, ETT SI; n=6) led to similar rapid lung volume recruitment (~6 min). In contrast, Mask continuous positive airway pressure (CPAP) without SI (n=6) resuscitation took longer (~30-45 min) to reach similar lung volume recruitment. The second main finding is that, in the first 15 min of postnatal life, the Mask CPAP without SI group closed their larynx during custom ventilator-driven expiration, leading to intratracheal positive end-expiratory pressure of ~17 cmH2O (instead of 8 cmH2O provided by the ventilator). In contrast, the Mask SI group used the larynx to limit inspiratory pressure to ~26 cmH2O (instead of 30 cmH2O provided by the ventilator). These different responses affected tidal volume, being larger in the Mask CPAP without SI group (8.4 ml/Kg, 6.7-9.3 IQR) compared to the Mask SI (5.0 ml/Kg, 4.4-5.2 IQR), and ETT SI groups (3.3 ml/Kg 2.6-3.7 IQR). Distinct physiological responses suggest that spontaneous respiratory activity of the larynx of preterm lambs at birth can uncouple pressure applied by the ventilator to that applied to the lung, leading to unpredictable lung pressure and tidal volumes delivery independently from the ventilator settings.

Physiological Effects of High-Flow Tracheal Oxygen in Tracheostomized Patients Weaning From Mechanical Ventilation.

High-flow tracheal oxygen (HFTO) is being used as supportive therapy during weaning in tracheostomized patients difficult to wean from invasive mechanical ventilation. There is, however, no clinical evidence for such a strategy. Therefore, we conducted a systematic review to summarize studies evaluating the physiologic effects of HFTO during tracheostomy-facilitated weaning and to identify potential areas for future research in this field. Observational and interventional studies on critically ill subjects weaning from mechanical ventilation via tracheostomy published until December 22, 2022, were eligible. Studies on high-flow oxygen, only in children, non-human models or animals, on clinical outcome only, abstracts without full-text availability, case reports, and reviews were excluded. Main outcomes were end-expiratory lung volume (EELV) and tidal volume using electrical impedance tomography, respiratory effort assessed by esophageal manometry, work of breathing and neuroventilatory drive as assessed by electrical activity of the diaphragm (EAdi) signal, airway pressure (Paw), oxygenation (PaO2 /FIO2 or SpO2 /FIO2 ), breathing frequency, tidal volume, and PaCO2 . In total, 1,327 references were identified, of which 5 were included. In all studies, HFTO was administered with flow 50 L/min and compared to conventional O2 therapy in a crossover design. The total average duration of invasive ventilation at time of measurements ranged from 11-27 d. In two studies, PaO2 /FIO2 and mean Paw were higher with HFTO. EELV, tidal volumes, esophageal pressure swings, and EAdi were similar during high-flow tracheal oxygen and conventional O2 therapy. The main physiological effect of HFTO as compared to conventional O2 therapy in tracheostomized subjects weaning from mechanical ventilation was improved oxygenation that is probably flow-dependent. Respiratory effort, lung aeration, neuroventilatory drive, and ventilation were similar for HFTO and conventional O2 therapy. Future studies on HFTO should be performed early in the weaning process and should evaluate its effect on sputum clearance and patient-centered outcomes like dyspnea.

Expiratory braking defines the breathing patterns of asphyxiated neonates during therapeutic hypothermia

IntroductionAlthough neonatal breathing patterns vary after perinatal asphyxia, whether they change during therapeutic hypothermia (TH) remains unclear. We characterized breathing patterns in infants during TH for hypoxic-ischemic encephalopathy (HIE) and normothermia after rewarming.MethodsIn seventeen spontaneously breathing infants receiving TH for HIE and in three who did not receive TH, we analyzed respiratory flow and esophageal pressure tracings for respiratory timing variables, pulmonary mechanics and respiratory effort. Breaths were classified as braked (inspiratory:expiratory ratio ≥1.5) and unbraked (&amp;lt;1.5).ResultsAccording to the expiratory flow shape braked breaths were chategorized into early peak expiratory flow, late peak expiratory flow, slow flow, and post-inspiratory hold flow (PiHF). The most braked breaths had lower rates, larger tidal volume but lower minute ventilation, inspiratory airway resistance and respiratory effort, except for the PiHF, which had higher resistance and respiratory effort. The braked pattern predominated during TH, but not during normothermia or in the uncooled infants.ConclusionsWe speculate that during TH for HIE low respiratory rates favor neonatal braked breathing to preserve lung volume. Given the generally low respiratory effort, it seems reasonable to leave spontaneous breathing unassisted. However, if the PiHF pattern predominates, ventilatory support may be required.

Dynamic inflation prevents and standardized lung recruitment reverts volume loss associated with percutaneous tracheostomy during volume control ventilation: results from a Neuro-ICU population.

To determine how percutaneous tracheostomy (PT) impacts on respiratory system compliance (Crs) and end-expiratory lung volume (EELV)during volume control ventilation and to test whether a recruitment maneuver (RM) at the end of PT may reverse lung derecruitment. This is a single center, prospective, applied physiology study. 25 patients with acute brain injury who underwent PT were studied. Patients were ventilated in volume control ventilation. Electrical impedance tomography (EIT) monitoring and respiratory mechanics measurements were performed in three steps: (a) baseline, (b) after PT, and (c) after a standardized RM (10 sighs of 30 cmH2O lasting 3s each within 1min). End-expiratory lung impedance (EELI) was used as a surrogate of EELV. PT determined a significant EELI loss (mean reduction of 432 arbitrary units p = 0.049) leading to a reduction in Crs (55 ± 13 vs. 62 ± 13 mL/cmH2O; p < 0.001) as compared to baseline. RM was able to revert EELI loss and restore Crs (68 ± 15 vs. 55 ± 13 mL/cmH2O; p < 0.001). In a subgroup of patients (N = 8, 31%), we observed a gradual but progressive increase in EELI. In this subgroup, patients did not experience a decrease of Crs after PT as compared to patients without dynamic inflation. Dynamic inflation did not cause hemodynamic impairment nor raising of intracranial pressure. We propose a novel and explorative hyperinflation risk index (HRI) formula. Volume control ventilation did not prevent the PT-induced lung derecruitment. RM could restore the baseline lung volume and mechanics. Dynamic inflation is common during PT, it can be monitored real-time by EIT and anticipated by HRI. The presence of dynamic inflation during PT may prevent lung derecruitment.

Inhibiting SHP2 reduces glycolysis, promotes microglial M1 polarization, and alleviates secondary inflammation following spinal cord injury in a mouse model

Abstract Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2 (SHP2), encoded by PTPN11, is widely expressed in the human body and plays a role in inflammation through various mechanisms. Therefore, SHP2 is considered a potential target for the treatment of inflammation-related diseases. However, its role in secondary inflammation after spinal cord injury remains unclear. In this study, SHP2 was found to be abundantly expressed in microglia at the site of spinal cord injury. Inhibition of SHP2 expression using siRNA and SHP2 inhibitors attenuated the microglial inflammatory response in an in vitro lipopolysaccharide-induced model of inflammation. Notably, after treatment with SHP2 inhibitors, mice with spinal cord injury exhibited significantly improved hind limb locomotor function and reduced residual urine volume in the bladder. Subsequent in vitro experiments showed that, in microglia stimulated with lipopolysaccharide, inhibiting SHP2 expression promoted M2 polarization and inhibited M1 polarization. Finally, a co-culture experiment was conducted to assess the effect of microglia treated with SHP2 inhibitors on neuronal cells. The results demonstrated that inflammatory factors produced by microglia promoted neuronal apoptosis, while inhibiting SHP2 expression mitigated these effects. Collectively, our findings suggest that SHP2 enhances secondary inflammation and neuronal damage subsequent to spinal cord injury by modulating microglial phenotype. Therefore, inhibiting SHP2 alleviates the inflammatory response in mice with spinal cord injury and promotes functional recovery postinjury.

Persistent disabilities 28 months after COVID-19 hospitalization, a prospective cohort study

BackgroundLimited data are available on long-term respiratory disabilities in patients following acute COVID-19.Patients and MethodsThis prospective, monocentric, observational cohort study included patients admitted to our hospital with acute COVID-19 between March 3 and April 24, 2020. Clinical, functional, and radiological data were collected up to 28 months after hospital discharge.ResultsAmong 715 patients hospitalized for COVID-19, 493 (69.0%) were discharged alive. We could access complete medical records for 268/493 patients (54.4%); 138/268 (51.5%) exhibited persistent respiratory symptoms and agreed with the data collection and follow-up. Patients were predominantly male (64.5%), with a mean (±sd) age of 58.9±15.3 years. At the last follow-up, the leading symptoms were asthenia (31.5%), dyspnoea (29.8%), and neuropsychological symptoms (17.7%). Lung function improved up to the last visit. Mean diffusing capacity of the lung for carbon monoxide (DLCO) was 77.8% of predicted value, total lung capacity (TLC) 83.5%, and O2desaturation during exercise (O2desaturation) −2.3%. While DLCO improved over the entire period, TLC improved in the early phase and O2desaturation in the late phase. Except for those with lung comorbidities, only one patient presented with minor functional and chest radiological alterations at 28-months.ConclusionPatients with acute COVID-19 discharged alive showed improved clinical symptoms, lung function parameters and radiological signs up to 28 months post infection. Persistent symptoms consisted mainly of asthenia and dyspnoea, with lung function returning to normal. One patient without prior respiratory issues exhibited moderate pulmonary fibrosis.