E-learning-an interventional element of the PRiVENT project to improve weaning expertise

BACKGROUND

PRiVENT (PRevention of invasive VENTilation) is an evaluation of a bundle of interventions aimed at the prevention of long-term invasive mechanical ventilation. One of these elements is an e-learning course for healthcare professionals to improve weaning expertise. The aim of our analysis is to examine the implementation of the course in cooperating intensive care units.

METHODS

The course has been developed through a peer review process by pulmonary and critical care physicians in collaboration with respiratory therapists, supported by health services researchers and a professional e-learning agency. The e-learning platform "weLearn" was made available online to participating healthcare professionals. Feedback on the e-learning programme was obtained and discussed in quality circles (QCs). We measured the acceptance and use of the programme through access statistics.

RESULTS

The e-learning course "Joint Prevention of Long-Term Ventilation" consists of 7 separate modules with practice-oriented training units as well as a cross-module area and corresponding interactive case studies. Users can receive 23 CME (continuing medical education) credits. The platform was released on July 1, 2021. By June 28, 2023, 214 users from 33 clinics had registered. Most users (77-98%) completed the modules, thus performing well in the test, where 90-100% passed. In the QCs, the users commended the structure and practical relevance of the programme, as well as the opportunity to earn CME credits.

CONCLUSION

Especially for medical staff in intensive care units, where continuous training is often a challenge during shift work, e-learning is a useful supplement to existing medical training.

TRIAL REGISTRATION

The PRiVENT study is registered at ClinicalTrials.gov (NCT05260853) on 02/03/2022.

[Interprofessional weaning boards and weaning consults for long-term ventilated patients: A qualitative study of perceived potential for patient care]

BACKGROUND

The PRiVENT project aims to improve the care of invasively ventilated patients and to reduce the number of out-of-hospital long-term ventilated patients. PRiVENT offers intensive care units the opportunity to exchange information with experts from specialized weaning centers in interprofessional weaning boards and weaning consults and to exploit the full weaning potential of the patients. In the context of the accompanying process evaluation, the PRiVENT intervention components will be examined for sustainability, scalability and effectiveness, and the interprofessional collaboration between intensive care units and the responsible weaning centers will be investigated in order to identify potentials for the care of invasively managed patients.

METHODS

In a qualitative cross-sectional study, semistructured, problem-oriented interviews were conducted with care providers of participating ICUs. The data were digitally recorded, pseudonymized and verbatim transcribed. Data analysis was based on Brown and Clarke's Thematic Analysis and the Consolidated Framework for Implementation Research. MAXQDA 2020 software was used to organize the data.

RESULTS

Fourteen interviews were conducted with ICU care providers. The early transfer of patients to a weaning center and the integration of pulmonary expertise into routine care were identified as positively perceived potentials of the weaning boards and weaning consults. Especially in critically ill, multimorbid patients suffering from COVID-19, the expertise of the weaning centers was considered helpful. Due to heavy workloads, nurses were unable to participate in weaning boards and weaning consults.

CONCLUSION

Interprofessional collaboration between weaning centers and ICUs in weaning boards and weaning consults can improve the care of invasively ventilated patients. Strategies to promote the involvement of nurses should be discussed and developed.

Causes and Risk Factors for Absenteeism among Medical Staff in German Specialized Lung Clinics during the COVID Pandemic

BACKGROUND

Staff shortages pose a major challenge to the health system.

OBJECTIVES

The objective of this study was to clarify the role of different causative factors we investigated on staff absenteeism during the COVID pandemic.

METHODS

The prospective multicentre cohort study assessed the private and professional impact of the pandemic on health care workers (HCWs) using a specially developed questionnaire. HCWs from 7 specialist lung clinics throughout Germany were surveyed from December 1 to December 23, 2021. The current analysis addresses pandemic-related absenteeism.

RESULTS

1,134 HCW (55% female; 18.4% male, 26.3% not willing to provide information on age or gender) participated. 72.8% had received at least one vaccination dose at the time of the survey, and 9.4% reported a COVID infection. Of those with positive tests, 98% reported home quarantine for median (IQR) 14 (12-17) days; 10.3% of those who ultimately tested negative also reported quarantine periods of 14 (7-14) days. 32.2% of vaccinated respondents reported absenteeism due to vaccine reactions of 2 (1-3) days. Overall, 37% (n = 420) of HCW reported pandemic-related absenteeism, with 3,524 total days of absenteeism, of which 2,828 were due to illness/quarantine and 696 to vaccination effects. Independent risk factors for COVID-related absenteeism ≥5 days included already having COVID, but also concern about long-term effects of COVID (OR 1,782, p = 0.014); risk factors for vaccine-related absenteeism ≥2 days included concerns of late effects of vaccination (OR 2.2, 95% CI: 1.4-3.1, p < 0.000).

CONCLUSION

Staff shortages due to quarantine or infections and vaccine reactogenicity have put a strain on German respiratory specialists. The fact that staff concerns also contributed to absenteeism may be helpful in managing future pandemic events to minimize staff absenteeism.

Mechanical Power Density Predicts Prolonged Ventilation Following Double Lung Transplantation

Prolonged mechanical ventilation (PMV) after lung transplantation poses several risks, including higher tracheostomy rates and increased in-hospital mortality. Mechanical power (MP) of artificial ventilation unifies the ventilatory variables that determine gas exchange and may be related to allograft function following transplant, affecting ventilator weaning. We retrospectively analyzed consecutive double lung transplant recipients at a national transplant center, ventilated through endotracheal tubes upon ICU admission, excluding those receiving extracorporeal support. MP and derived indexes assessed up to 36 h after transplant were correlated with invasive ventilation duration using Spearman's coefficient, and we conducted receiver operating characteristic (ROC) curve analysis to evaluate the accuracy in predicting PMV (>72 h), expressed as area under the ROC curve (AUROC). PMV occurred in 82 (35%) out of 237 cases. MP was significantly correlated with invasive ventilation duration (Spearman's ρ = 0.252 [95% CI 0.129-0.369], p < 0.01), with power density (MP normalized to lung-thorax compliance) demonstrating the strongest correlation (ρ = 0.452 [0.345-0.548], p < 0.01) and enhancing PMV prediction (AUROC 0.78 [95% CI 0.72-0.83], p < 0.01) compared to MP (AUROC 0.66 [0.60-0.72], p < 0.01). Mechanical power density may help identify patients at risk for PMV after double lung transplantation.

Ventilatory ratio and mechanical power in prolonged mechanically ventilated COVID-19 patients versus respiratory failures of other etiologies

BACKGROUND

Evidence suggests differences in ventilation efficiency and respiratory mechanics between early COVID-19 pneumonia and classical acute respiratory distress syndrome (ARDS), as measured by established ventilatory indexes, such as the ventilatory ratio (VR; a surrogate of the pulmonary dead-space fraction) or mechanical power (MP; affected, e.g., by changes in lung-thorax compliance).

OBJECTIVES

The aim of this study was to evaluate VR and MP in the late stages of the disease when patients are ready to be liberated from the ventilator after recovering from COVID-19 pneumonia compared to respiratory failures of other etiologies.

DESIGN

A retrospective observational cohort study of 249 prolonged mechanically ventilated, tracheotomized patients with and without COVID-19-related respiratory failure.

METHODS

We analyzed each group's VR and MP distributions and trajectories [repeated-measures analysis of variance (ANOVA)] during weaning. Secondary outcomes included weaning failure rates between groups and the ability of VR and MP to predict weaning outcomes (using logistic regression models).

RESULTS

The analysis compared 53 COVID-19 cases with a heterogeneous group of 196 non-COVID-19 subjects. VR and MP decreased across both groups during weaning. COVID-19 patients demonstrated higher values for both indexes throughout weaning: median VR 1.54 versus 1.27 (p < 0.01) and MP 26.0 versus 21.3 Joule/min (p < 0.01) at the start of weaning, and median VR 1.38 versus 1.24 (p < 0.01) and MP 24.2 versus 20.1 Joule/min (p < 0.01) at weaning completion. According to the multivariable analysis, VR was not independently associated with weaning outcomes, and the ability of MP to predict weaning failure or success varied with lung-thorax compliance, with COVID-19 patients demonstrating consistently higher dynamic compliance along with significantly fewer weaning failures (9% versus 30%, p < 0.01).

CONCLUSION

COVID-19 patients differed considerably in ventilation efficiency and respiratory mechanics among prolonged ventilated individuals, demonstrating significantly higher VRs and MP. The differences in MP were linked with higher lung-thorax compliance in COVID-19 patients, possibly contributing to the lower rate of weaning failures observed.

Risk Factors for Prolonged Mechanical Ventilation and Weaning Failure: A Systematic Review

INTRODUCTION

Prolonged mechanical ventilation (PMV) and weaning failure are factors associated with prolonged hospital length of stay and increased morbidity and mortality. In addition to the burden these places on patients and their families, it also imposes high costs on the public health system. The aim of this systematic review was to identify risk factors for PMV and weaning failure.

METHODS

The study was conducted according to PRISMA guidelines. After a comprehensive search of the COCHRANE Library, CINHAL, Web of Science, MEDLINE, and the LILACS Database a PubMed request was made on June 8, 2020. Studies that examined risk factors for PMV, defined as mechanical ventilation ≥96 h, weaning failure, and prolonged weaning in German and English were considered eligible; reviews, meta-analyses, and studies in very specific patient populations whose results are not necessarily applicable to the majority of ICU patients as well as pediatric studies were excluded from the analysis. This systematic review was registered in the PROSPERO register under the number CRD42021271038.

RESULTS

Of 532 articles identified, 23 studies with a total of 23,418 patients met the inclusion criteria. Fourteen studies investigated risk factors of PMV including prolonged weaning, 9 studies analyzed risk factors of weaning failure. The concrete definitions of these outcomes varied considerably between studies. For PMV, a variety of risk factors were identified, including comorbidities, site of intubation, various laboratory or blood gas parameters, ventilator settings, functional parameters, and critical care scoring systems. The risk of weaning failure was mainly related to age, previous home mechanical ventilation (HMV), cause of ventilation, and preexisting underlying diseases. Elevated PaCO2 values during spontaneous breathing trials were indicative of prolonged weaning and weaning failure.

CONCLUSION

A direct comparison of risk factors was not possible because of the heterogeneity of the studies. The large number of different definitions and relevant parameters reflects the heterogeneity of patients undergoing PMV and those discharged to HMV after unsuccessful weaning. Multidimensional scores are more likely to reflect the full spectrum of patients ventilated in different ICUs than single risk factors.

Incidence, causes, and predictors of unsuccessful decannulation following prolonged weaning

Background

Liberation from prolonged tracheostomy ventilation involves ventilator weaning and removal of the tracheal cannula (referred to as decannulation). This study evaluated the incidence, causes, and predictors of unsuccessful decannulation following prolonged weaning.

Methods

Observational retrospective cohort study of 532 prolonged mechanically ventilated, tracheotomized patients treated at a specialized weaning center between June 2013 and January 2021. We summarized the causes for unsuccessful decannulations and used a binary logistic regression analysis to derive and validate associated predictors.

Results

Failure to decannulate occurred in 216 patients (41%). The main causes were severe intensive care unit (ICU)-acquired dysphagia (64%), long-term ventilator dependence following weaning failure (41%), excessive respiratory secretions (12%), unconsciousness (4%), and airway obstruction (3%). Predictors of unsuccessful decannulation from any cause were age [odds ratio (OR) = 1.04 year^-1; 95% confidence interval (CI), 1.02-1.06; p < 0.01], body mass index [0.96 kg/m² (0.93-1.00); p = 0.027], Acute Physiology and Chronic Health Evaluation II (APACHE-II) score [1.05 (1.00-1.10); p = 0.036], pre-existing non-invasive home ventilation [3.57 (1.51-8.45); p < 0.01], percutaneous tracheostomies [0.49 (0.30-0.80); p < 0.01], neuromuscular diseases [4.28 (1.21-15.1); p = 0.024], and total mechanical ventilation duration [1.02 day^-1 (1.01-1.02); p < 0.01]. Regression models examined in subsets of patients with severe dysphagia and long-term ventilator dependence as the main reason for failure revealed little overlapping among predictors, which even showed opposite effects on the outcome. The application of non-invasive ventilation as a weaning technique contributed to successful decannulation in 96 of 221 (43%) long-term ventilator-dependent patients following weaning failure.

Conclusion

Failure to decannulate after prolonged weaning occurred in 41%, mainly resulting from persistent ICU-acquired dysphagia and long-term ventilator dependence following weaning failure, each associated with its own set of predictors.

Impact of Lung Function Decline on Mortality in Lung Transplant Recipients: Long-Term Results From the L-CsA-i Study for the Prevention of Bronchiolitis Obliterans Syndrome

Background

Chronic lung allograft dysfunction (CLAD) is defined by a progressive loss of FEV1 and is associated with premature mortality. The aim of this study was to investigate the direct association between FEV1 decline and risk of mortality in patients after lung transplantation (LTx).

Methods

10-year follow up data from lung transplant recipients participating in randomized placebo-controlled clinical trial investigating the role of liposomal Cyclosporine A for inhalation (L-CsA-i) in the prevention of bronchiolitis obliterans syndrome (NCT01334892) was used. The association between the course of FEV1 over time and the risk of mortality was assessed using joint modeling and Cox regression analysis.

Results

A total of 130 patients were included. Predictors of FEV1 decline were a higher absolute FEV1 at baseline and male sex. The joint model analysis indicated a significant association of change of FEV1 and risk of mortality (p < 0.001), with a predicted 3.4% increase in mortality risk for each 1% decline in FEV1. Significant predictors of a progressive phenotype were single LTx and treatment with placebo (as opposed to L-CsA-i). At the end of follow-up, 82 patients (63.1%) were still alive. Cox regression analyses for mortality identified only single LTx as a predictor of higher risk.

Conclusion

Based on our observation of a close association between FEV1 and mortality over a period of 10 years we suggest FEV1 as a valid predictor of mortality and a suitable surrogate endpoint in the investigation of early interventions.

Oxygenated Hemoglobin Predicts Outcome in Patients with Chronic Lung Allograft Dysfunction

BACKGROUND

Long-term outcome of lung transplantation (LTx) recipients is limited by chronic lung allograft dysfunction (CLAD). In this setting of new onset respiratory failure, the amount of oxygenated hemoglobin (OxyHem; hemoglobin (Hb) concentration × fractional oxygen saturation) may provide valuable information.

OBJECTIVE

We hypothesized that OxyHem predicts survival of LTx recipients at the onset of CLAD.

METHODS

Data from 292 LTx recipients with CLAD were analyzed. After excluding patients with missing data or supplemental oxygen, the final population comprised 218 patients. The relationship between survival upon CLAD and OxyHem was analyzed by Cox regression analyses and ROC curves.

RESULTS

Among the 218 patients (102 males, 116 females), 128 (58.7%) died, median survival time after CLAD onset being 1,156 days. Survival was significantly associated with type of transplantation, time to CLAD, CLAD stage at onset, and OxyHem, which was superior to Hb or oxygen saturation. The risk for death after CLAD increased by 14% per reduction of OxyHem by 1 g/dL, and values below 11 g/dL corresponded to an 80% increase in mortality risk.

CONCLUSION

Thus, OxyHem was identified as an independent predictor of mortality after CLAD onset. Whether it is useful in supporting therapeutic decisions and potentially home monitoring in the surveillance of lung transplant recipients has to be studied further.

Tracheal stenosis in prolonged mechanically ventilated patients: prevalence, risk factors, and bronchoscopic management

Background

Various complications may arise from prolonged mechanical ventilation, but the risk of tracheal stenosis occurring late after translaryngeal intubation or tracheostomy is less common. This study aimed to determine the prevalence, type, risk factors, and management of tracheal stenoses in mechanically ventilated tracheotomized patients deemed ready for decannulation following prolonged weaning.

Methods

A retrospective observational study on 357 prolonged mechanically ventilated, tracheotomized patients admitted to a specialized weaning center over seven years. Flexible bronchoscopy was used to discern the type, level, and severity of tracheal stenosis in each case. We described the management of these stenoses and used a binary logistic regression analysis to determine independent risk factors for stenosis development.

Results

On admission, 272 patients (76%) had percutaneous tracheostomies, and 114 patients (32%) presented mild to moderate tracheal stenosis following weaning completion, with a median tracheal cross-section reduction of 40% (IQR 25–50). The majority of stenoses (88%) were located in the upper tracheal region, most commonly resulting from localized granulation tissue formation at the site of the internal stoma (96%). The logistic regression analysis determined that obesity (OR 2.16 [95%CI 1.29–3.63], P < 0.01), presence of a percutaneous tracheostomy (2.02 [1.12–3.66], P = 0.020), and cricothyrotomy status (5.35 [1.96–14.6], P < 0.01) were independently related to stenoses. Interventional bronchoscopy with Nd:YAG photocoagulation was a highly effective first-line treatment, with only three patients (2.6%) ultimately referred to tracheal surgery.

Conclusions

Tracheal stenosis is commonly observed among prolonged ventilated patients with tracheostomies, characterized by localized hypergranulation and mild to moderate airway obstruction, with interventional bronchoscopy providing satisfactory results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01821-6.

A randomized controlled trial of liposomal cyclosporine A for inhalation in the prevention of bronchiolitis obliterans syndrome following lung transplantation

Long-term survival after lung transplantation is limited by chronic allograft dysfunction. The aim of this study was to investigate the effect of locally augmented immunosuppression with liposomal cyclosporine A for inhalation (L-CsA-i) for the prevention of bronchiolitis obliterans syndrome (BOS). In a randomized, double-blind, placebo-controlled, multi-center Phase 3 study, 180 LT recipients in BOS grade 0 were planned to receive L-CsA-i or placebo in addition to triple-drug immunosuppression. L-CsA-i was administered twice daily via an Investigational eFlow nebulizer to recipients of single (SLT) and bilateral lung transplants (BLT) within 6-32 weeks posttransplant, and continued for 2 years. The primary endpoint was BOS-free survival. 130 patients were enrolled before the study was prematurely terminated for business reasons. Despite a 2-year actuarial difference in BOS-free survival of 14.1% in favor of L-CsA-i in the overall study population, the primary endpoint was not met (p = .243). The pre-defined per protocol analysis of SLT recipients (n = 24) resulted in a treatment difference of 58.2% (p = .053). No difference was observed in the BLT (n = 48) subpopulation (p = .973). L-CsA-i inhalation was well tolerated. Although this study failed to meet its primary endpoint, the results warrant additional investigation of L-CsA-i in lung transplant recipients.

Polyomavirus exerts detrimental effects on renal function in patients after lung transplantation

INTRODUCTION

Chronic kidney disease (CKD) is associated with significant morbidity and mortality after lung transplantation (LTX). Calcineurin inhibitor (CNI) nephrotoxicity is the leading cause of CKD. After kidney transplantation, polyomavirus-associated nephropathy (PyVAN) is a well-recognized problem. This study aims to evaluate the role of polyomavirus in patients after LTX.

METHODS

From January 2017 to January 2020, all lung transplant recipients who performed follow-up visits in our center were included in the study and retrospectively assessed. We measured renal function (creatinine levels before and after transplantation), JCPyV, and BKPyV load by polymerase chain reaction (PCR) in serum and urine samples after transplantation.

RESULTS

In total, 104 consecutive patients (59 males, 56.7%) with a mean age of 49.6 ± 11.1 years were identified. JCPyV was found in urine of 36 patients (34.6%) and serum of 3 patients (2.9%). BKPyV was found in urine of 40 patients (38.5%) and serum of 4 patients (3.8%), respectively. Urine evidence for JCPyV (p < 0.001, coefficient: +21.44) and BKPyV (p < 0.001, coefficient: +29.65) correlated highly with further kidney function decline.

CONCLUSION

Kidney function deterioration is associated with JCPyV and BKPyV viruria in patients after LTX. This might indicate a role of PyVAN in lung transplant recipients.

Pulmonary function impairment of asymptomatic and persistently symptomatic patients 4 months after COVID-19 according to disease severity

Objective

Evaluation of pulmonary function impairment after COVID-19 in persistently symptomatic and asymptomatic patients of all disease severities and characterisation of risk factors.

Methods

Patients with confirmed SARS-CoV-2 infection underwent prospective follow-up with pulmonary function testing and blood gas analysis during steady-state cycle exercise 4 months after acute illness. Pulmonary function impairment (PFI) was defined as reduction below 80% predicted of DLCOcSB, TLC, FVC, or FEV1. Clinical data were analyzed to identify risk factors for impaired pulmonary function.

Results

76 patients were included, hereof 35 outpatients with mild disease and 41 patients hospitalized due to COVID-19. Sixteen patients had critical disease requiring mechanical ventilation, 25 patients had moderate–severe disease. After 4 months, 44 patients reported persisting respiratory symptoms. Significant PFI was prevalent in 40 patients (52.6%) occurring among all disease severities. The most common cause for PFI was reduced DLCOcSB (n = 39, 51.3%), followed by reduced TLC and FVC. The severity of PFI was significantly associated with mechanical ventilation (p < 0.001). Further risk factors for DLCO impairment were COPD (p < 0.001), SARS-CoV-2 antibody-Titer (p = 0.014) and in hospitalized patients CT score. A decrease of paO2 > 3 mmHg during cycle exercise occurred in 1/5 of patients after mild disease course.

Conclusion

We characterized pulmonary function impairment in asymptomatic and persistently symptomatic patients of different severity groups of COVID-19 and identified further risk factors associated with persistently decreased pulmonary function. Remarkably, gas exchange abnormalities were revealed upon cycle exercise in some patients with mild disease courses and no preexisting pulmonary condition.

Supplementary Information

The online version contains supplementary material available at 10.1007/s15010-021-01669-8.

Mechanical power normalized to lung-thorax compliance predicts prolonged ventilation weaning failure: a prospective study

Background

Mechanical power (MP) of artificial ventilation, the energy transferred to the respiratory system, is a chief determinant of adequate oxygenation and decarboxylation. Calculated MP, the product of applied airway pressure and minute ventilation, may serve as an estimate of respiratory muscle workload when switching to spontaneous breathing. The aim of the study was to assess MP’s discriminatory performance in predicting successful weaning from prolonged tracheostomy ventilation.

Methods

Prospective, observational study in 130 prolonged mechanically ventilated, tracheotomized patients in a specialized weaning center. Predictive weaning outcome ability of arterial blood gas analyses and indices derived from calculated MP at beginning and end of weaning was determined in terms of area under receiver operating characteristic curve (AUROC) and measures derived from k-fold cross-validation (likelihood ratios, diagnostic odds ratio, F₁ score, and Matthews correlation coefficient [MCC]).

Results

Forty-four (33.8%) patients experienced weaning failure. Absolute MP showed poor discrimination in predicting outcome; whereas specific MP (MP normalized to dynamic lung-thorax compliance, LTC_dyn-MP) had moderate diagnostic accuracy (MCC 0.38; AUROC 0.79, 95%CI [0.71‒0.86], p < 0.001), further improved by correction for corresponding mechanical ventilation P_aCO₂ (termed the power index of the respiratory system [PI_rs]: MCC 0.52; AUROC 0.86 [0.79‒0.92], p < 0.001). Diagnostic performance of MP indices increased over the course of weaning, with maximum accuracy immediately before completion (LTC_dyn-MP: MCC 0.49; AUROC 0.86 [0.78‒0.91], p < 0.001; PI_rs: MCC 0.68; AUROC 0.92 [0.86‒0.96], p < 0.001).

Conclusions

MP normalized to dynamic lung-thorax compliance, a surrogate for applied power per unit of ventilated lung volume, accurately discriminated between low and high risk for weaning failure following prolonged mechanical ventilation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01566-8.

Diagnostic yield, safety, and impact of transbronchial lung biopsy in mechanically ventilated, critically ill patients: a retrospective study

Background

Pulmonary infiltrates of variable etiology are one of the main reasons for hypoxemic respiratory failure leading to invasive mechanical ventilation. If pulmonary infiltrates remain unexplained or progress despite treatment, the histopathological result of a lung biopsy could have significant impact on change in therapy. Surgical lung biopsy is the commonly used technique, but due to its considerable morbidity and mortality, less invasive bronchoscopic transbronchial lung biopsy (TBLB) may be a valuable alternative.

Methods

Retrospective, monocentric, observational study in mechanically ventilated, critically ill patients, subjected to TBLB due to unexplained pulmonary infiltrates in the period January 2014 to July 2019. Patients’ medical records were reviewed to obtain data on baseline clinical characteristics, modality and adverse events (AE) of the TBLB, and impact of the histopathological results on treatment decisions. A multivariable binary logistic regression analysis was performed to identify predictors of AE and hospital mortality, and survival curves were generated using the Kaplan-Meier method.

Results

Forty-two patients with in total 42 TBLB procedures after a median of 12 days of mechanical ventilation were analyzed, of which 16.7% were immunosuppressed, but there was no patient with prior lung transplantation. Diagnostic yield of TBLB was 88.1%, with AE occurring in 11.9% (most common pneumothorax and minor bleeding). 92.9% of the procedures were performed as a forceps biopsy, with organizing pneumonia (OP) as the most common histological diagnosis (54.8%). Variables independently associated with hospital mortality were age (odds ratio 1.070, 95%CI 1.006–1.138; p = 0.031) and the presence of OP (0.182, [0.036–0.926]; p = 0.040), the latter being confirmed in the survival analysis (log-rank p = 0.040). In contrast, a change in therapy based on histopathology alone occurred in 40.5%, and there was no evidence of improved survival in those patients.

Conclusions

Transbronchial lung biopsy remains a valuable alternative to surgical lung biopsy in mechanically ventilated critically ill patients. However, the high diagnostic yield must be weighed against potential adverse events and limited consequence of the histopathological result regarding treatment decisions in such patients.

Interstitial and Granulomatous Lung Disease in Inflammatory Bowel Disease Patients

BACKGROUND

Interstitial lung [ILD] disease and granulomatous lung disease [GLD] are rare respiratory disorders that have been associated with inflammatory bowel disease [IBD]. Clinical presentation is polymorphic and aetiology is unclear.

METHODS

This was an ECCO-CONFER project. Cases of concomitant ILD or GLD and IBD, or drug-induced ILD/GLD, were collected. The criteria for diagnosing ILD and GLD were based on definitions from the American Thoracic Society and the European Respiratory Society and on the discretion of reporting clinician.

RESULTS

We identified 31 patients with ILD. The majority had ulcerative colitis [UC] [n = 22]. Drug-related ILD was found in 64% of these patients, 25 patients [80.6%] required hospitalisation, and one required non-invasive ventilation. The causative drug was stopped in all drug-related ILD, and 87% of patients received systemic steroids. At follow-up, 16% of patients had no respiratory symptoms, 16% had partial improvement, 55% had ongoing symptoms, and there were no data in 13%. One patient was referred for lung transplantation, and one death from lung fibrosis was reported. We also identified 22 GLD patients: most had Crohn's disease [CD] [n = 17]. Drug-related GLD was found in 36% of patients and 10 patients [45.4%] required hospitalisation. The causative drug was stopped in all drug-related GLD, and 81% of patients received systemic steroids. Remission of both conditions was achieved in almost all patients.

CONCLUSIONS

ILD and GLD, although rare, can cause significant morbidity. In our series, over half of cases were drug-related and therefore focused pharmacovigilance is needed to identify and manage these cases.

Variables predicting weaning outcome in prolonged mechanically ventilated tracheotomized patients: a retrospective study

Background

Several studies have assessed predictors of weaning and extubation outcome in short-term mechanically ventilated patients, but there are only few studies on predictors of weaning from prolonged mechanical ventilation.

Methods

Retrospective, single-center, observational study at a specialized national weaning center in Germany. Patients’ medical records were reviewed to obtain data on demographics, comorbidities, respiratory indices, and the result of a prospectively documented, standardized spontaneous breathing trial (SBT) upon admission to the weaning center. Respiratory indices assessed were the ventilatory ratio (VR) and parameters derived from calculated mechanical power (MP). Predictors associated with failure of prolonged weaning and failure of the SBT were assessed using a binary logistic regression model.

Results

A total of 263 prolonged mechanically ventilated, tracheotomized patients, treated over a 5-year period were analyzed. After 3 weeks of mechanical ventilation, patients with unsuccessful weaning failed a SBT more frequently and showed significantly increased values for inspiratory positive airway pressure, driving pressure, VR, absolute MP, and MP normalized to predicted body weight and dynamic lung-thorax compliance (LTC-MP). In the logistic regression analyses, variables independently correlated with weaning failure were female gender (adjusted odds ratio 0.532 [95% CI 0.291–0.973]; p = 0.040), obesity (body mass index ≥ 30 kg/m²) (2.595 [1.210–5.562]; p = 0.014), COPD (3.209 [1.563–6.589]; p = 0.002), LTC-MP (3.470 [1.067–11.284]; p = 0.039), P_aCO₂ on mechanical ventilation (1.101 [95% CI 1.034–1.173]; p = 0.003), and failure of the SBT (4.702 [2.250–9.825]; p < 0.001). In addition, female gender (0.401 [0.216–0.745]; p = 0.004), LTC-MP (3.017 [1.027–8.862]; p = 0.046), and P_aCO₂ on mechanical ventilation (1.157 [1.083–1.235]; p < 0.001) were independent risk factors for an unsuccessful SBT.

Conclusions

In the present study, the derived predictors of weaning point to a crucial role of the workload imposed on respiratory muscles during spontaneous breathing. Mechanical power normalized to lung-thorax compliance was independently correlated with weaning outcome and may identify patients at high risk for weaning failure.

Anemia and red blood cell transfusion practice in prolonged mechanically ventilated patients admitted to a specialized weaning center: an observational study

Background

The impact of anemia and red blood cell (RBC) transfusion on weaning from mechanical ventilation is not known. In theory, transfusions could facilitate liberation from the ventilator by improving oxygen transport capacity. In contrast, retrospective studies of critically ill patients showed a positive correlation of transfusions with prolonged mechanical ventilation, increased mortality rates, and increased risk of nosocomial infections, which in turn could adversely affect weaning outcome.

Methods

Retrospective, observational study on prolonged mechanically ventilated, tracheotomized patients (n = 378), admitted to a national weaning center over a 5 year period. Medical records were reviewed to obtain data on patients’ demographics, comorbidities, blood counts, transfusions, weaning outcome, and nosocomial infections, defined according to the criteria of the U.S. Centers for Disease Control and Prevention. The impact of RBC transfusion on outcome measures was assessed using regression models.

Results

Ninety-eight percent of all patients showed anemia on admission to the weaning center. Transfused and non-transfused patients differed significantly regarding disease severity and comorbidities. In multivariate analyses, RBC transfusion, but not mean hemoglobin concentration in the course of weaning, was independently correlated with weaning duration (adjusted β 12.386, 95% CI 9.335–15.436; p <  0.001) and hospital length of stay (adjusted β 16.116, 95% CI 8.925–23.306; p <  0.001); there was also a trend toward increased hospital mortality (adjusted odds ratio [OR] 2.050, 95% CI 0.995–4.224; p = 0.052), but there was no independent correlation with weaning outcome or nosocomial infections. In contrast, hemoglobin level on the day of admission to the weaning center was independently associated with hospital mortality (adjusted OR 0.956, 95% CI 0.924–0.989; p = 0.010), appearing significantly elevated at values below 8.5 g/dl (AUC 0.670, 95% CI 0.593–0.747; p <  0.001).

Conclusions

A high percentage of prolonged mechanically ventilated patients showed anemia on admission to the weaning center. RBC transfusion was independently correlated with worse outcomes. Since transfused patients differed significantly regarding their clinical characteristics and comorbidities, RBC transfusion might be an indicator of disease severity rather than directly impacting patient prognosis.

Gender and age differences in eating and drinking risk behaviors in Italian high school students

Drunkorexia, limiting food intake before alcohol consumption, increases teenagers and young adults’ risk for negative alcohol-related health consequences.

The purpose of the present study is to explore gender and age differences regarding weight management behaviors and alcohol consumption among 3004 students aged 13 to 24 years.

The following questionnaires were administered: Eating Disorder Inventory-3 (EDI-3), Alcohol Use Disorders Identification Test (AUDIT) and Compensatory Eating and Behaviors in Response to Alcohol Consumption Scale (CEBRACS).

EDI-3 showed that 11.3% of the sample met the threshold on the “Drive for Thinness” (DT) scale, 28.9% on the “Bulimia” (B) scale, 17.2% on the “Body Dissatisfaction” (BD) scale. Females presented a higher risk at DT, B and BD scales (P < 0.001), and the risk of bulimia was higher in those aged ≤ 16 years (P = 0.028). AUDIT revealed a greater clinical risk of alcohol-related problems in males (P < 0.001) and in those aged > 16 years (P < 0.001). Drunkorexia was found in 44% of the sample, without significant difference in relation to gender and age.

Girls and younger students have more weight concerns, while boys and older students are at greater risk of alcohol use disorders. Therefore, no specific group should be considered risk-free with respect to drunkorexia.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Specific Changes of Exocarp and Mesocarp Occurring during Softening Differently Affect Firmness in Melting (MF) and Non Melting Flesh (NMF) Fruits

Melting (MF) and non melting flesh (NMF) peaches differ in their final texture and firmness. Their specific characteristics are achieved by softening process and directly dictate fruit shelf life and quality. Softening is influenced by various mechanisms including cell wall reorganization and water loss. In this work, the biomechanical properties of MF Spring Crest's and NMF Oro A's exocarp and mesocarp along with the amount and localization of hydroxycinnamic acids and flavonoids were investigated during fruit ripening and post-harvest. The objective was to better understand the role played by water loss and cell wall reorganization in peach softening. Results showed that in ripe Spring Crest, where both cell turgor loss and cell wall dismantling occurred, mesocarp had a little role in the fruit reaction to compression and probe penetration response was almost exclusively ascribed to the epidermis which functioned as a mechanical support to the pulp. In ripe Oro A's fruit, where cell wall disassembly did not occur and the loss of cell turgor was observed only in mesocarp, the contribution of exocarp to fruit firmness was consistent but relatively lower than that of mesocarp, suggesting that in addition to cell turgor, the integrity of cell wall played a key role in maintaining NMF fruit firmness. The analysis of phenols suggested that permeability and firmness of epidermis were associated with the presence of flavonoids and hydroxycinnamic acids.

Ragweed pollen collected along high-traffic roads shows a higher allergenicity than pollen sampled in vegetated areas

BACKGROUND

Pollutants may affect pollen allergenicity and thus the prevalence of allergies. Although a few studies are available in literature, the connection between pollution and the allergenic potential of pollen has yet to be clearly defined. The objective of this study was to evaluate the effect of traffic-related pollution on the allergenicity of ragweed (Ambrosia artemisiifolia L.) pollen through a field-based experiment.

METHODS

Mature pollen grains were collected from ragweed plants grown along main roadsides and in vegetated areas of Po river plain. The percentage of sub-pollen particle-releasing grains (SPPGs) was evaluated immediately after sampling by microscope and image analysis. Immunochemistry and LC-MS/MS were applied to assess the whole allergenicity and the allergen pattern characterizing the different pollen samples.

RESULTS

No statistical difference was detected in the percentage of SPPGs among pollen samples. Specifically, after hydration, the mean percentage was very low (<4%) in all the samples, regardless of the site of origin. On the contrary, pollen collected along high-traffic roads showed a higher whole allergenicity than pollen from low-traffic roads and vegetated areas which showed a reactivity similar to that of the commercial pollen 'Allergon', used as a standard. The detected higher allergenicity levels were attributed to both quantitative and qualitative differences in allergen pattern.

CONCLUSION

Our findings show that pollen collected at different sites contains different amount and number of allergens and suggest that traffic-related pollution enhances ragweed pollen allergenicity, which may contribute to the increasing prevalence of ragweed allergy in Lombardy plain.

A comparative study of melting and non-melting flesh peach cultivars reveals that during fruit ripening endo-polygalacturonase (endo-PG) is mainly involved in pericarp textural changes, not in firmness reduction

Peach softening is usually attributed to the dismantling of the cell wall in which endo-polygalacturonase (endo-PG)-catalysed depolymerization of pectins plays a central role. In this study, the hypothesis that the function of endo-PG is critical for achieving a melting flesh fruit texture but not for reducing fruit firmness was tested by comparing pericarp morphology and endo-PG expression and localization in melting (MF) and non-melting flesh (NMF) fruit at successive stages of ripening. MF Bolero, Springbelle, and Springcrest, and NMF Oro-A and Jonia cultivars were analysed. Both MF and NMF fruit were left to ripen on the tree and reached a firmness of <10 Newtons (N). The image analysis of pericarp tissues revealed that during softening the loss of cell turgidity was a process common to mesocarp cells of all MF and NMF fruit and was clearly visible in peaches with a firmness of less than ∼20 N. In contrast, the loss of cell adhesion was a feature exclusively observed in ripe MF fruit pericarp. In this ripe fruit, large numbers of endo-PG isoforms were highly expressed and the enzyme localization corresponded to the middle lamella. As a consequence, wide apoplastic spaces characterized the pericarp of ripe MF peaches. In contrast, no loss of cell adhesion was observed in any NMF fruit or in unripe MF peaches. Accordingly, no endo-PG was detected in unripe NMF fruit, whereas few and poorly expressed enzyme isoforms were revealed in ripe NMF and in unripe MF peaches. In this fruit, the poorly expressed endo-PG localized mainly in vesicles within the cytoplasm and inner primary cell wall. On the whole the results suggested that endo-PG function was needed to achieve melting flesh texture, which was characterized by wide apoplastic spaces and partially deflated mesocarp cells. Conversely, endo-PG activity had no critical influence on the reduction of fruit firmness given the capacity of NMF peaches to soften, reaching values of 5-10 N. As in tomato, the change of symplast/apoplast water status seems to be the main process through which peach fruit regulates its firmness.

Exposure to cadmium-contaminated soils increases allergenicity of Poa annua L. pollen

BACKGROUND

Pollution is considered as one main cause for the increase of allergic diseases. Air pollutants may cause and worsen airway diseases and are probably able to make pollen allergens more aggressive. Previous studies looked at traffic-related air pollution, but no data about the effects of polluted soils on pollen allergens are available. We aimed to assess the effects of plant exposure to cadmium-contaminated soil on allergenicity of the annual blue grass, Poa annua L, pollen.

METHODS

Poa plants were grown in soil contaminated or not contaminated (control) with cadmium. At flowering, mature pollen was analyzed by microscopy, to calculate the percentage of pollen grains releasing cytoplasmic granules, and by proteomic techniques to analyze allergen proteins. Allergens were identified by sera from grass pollen-allergic patients and by mass spectrometry.

RESULTS

Pollen from Cd-exposed plants released a higher amount of allergenic proteins than control plants. Moreover, Cd-exposed pollen released allergens-containing cytoplasmic grains much more promptly than control pollen. Group 1 and 5 allergens, the major grass pollen allergens, were detected both in control and Cd-exposed extracts. These were the only allergens reacting with patient's sera in control pollen, whereas additional proteins strengthening the signal in the gel region reacting with patient's sera were present in Cd-exposed pollen. These included a pectinesterase, a lipase, a nuclease, and a secretory peroxydase. Moreover, a PR3 class I chitinase-like protein was also immunodetected in exposed plants.

CONCLUSION

Pollen content of plants grown in Cd-contaminated soils is more easily released in the environment and also shows an increased propensity to bind specific IgE.

Changes in endopolygalacturonase levels and characterization of a putative endo-PG gene during fruit softening in peach genotypes with nonmelting and melting flesh fruit phenotypes

The changes in endopolygalacturonase (endo-PG) levels and endo-PG expression in nonmelting flesh (NMF) and melting flesh (MF) peach fruits (Prunus persica) during softening were studied. The endo-PG gene was analysed to identify polymorphisms exploitable for early marker-assisted selection (MAS) of flesh texture. The role of endo-PG in softening was assessed by western and northern blotting and by biochemical analyses. Polymorphisms in the endo-PG gene were revealed by reverse transcription-polymerase chain reaction (RT-PCR) and sequencing. An endo-PG protein was detected in both NMF and MF fruits. The levels of this endo-PG protein were higher and increased with softening in MF fruits, but remained lower and were constant in NMF fruits. The different levels of endo-PG appeared to be caused by the differential expression of an endo-PG gene, whose open-reading frame (ORF) showed five single nucleotide polymorphisms (SNPs) in NMF 'Oro A' compared with MF 'Bolero'. One of these SNPs allowed us to determine the allelic configuration at the melting flesh (M) locus and also seemed to be exploitable for early MAS in other NMF/MF phenotypes. The NMF phenotype does not seem to be caused by a large deletion of the endo-PG gene.

Resolution of viable and membrane-compromised bacteria in freshwater and marine waters based on analytical flow cytometry and nucleic acid double staining

The membrane integrity of a cell is a well-accepted criterion for characterizing viable (active or inactive) cells and distinguishing them from damaged and membrane-compromised cells. This information is of major importance in studies of the function of microbial assemblages in natural environments, in order to assign bulk activities measured by various methods to the very active cells that are effectively responsible for the observations. To achieve this task for bacteria in freshwater and marine waters, we propose a nucleic acid double-staining assay based on analytical flow cytometry, which allows us to distinguish viable from damaged and membrane-compromised bacteria and to sort out noise and detritus. This method is derived from the work of S. Barbesti et al. (Cytometry 40:214-218, 2000) which was conducted on cultured bacteria. The principle of this approach is to use simultaneously a permeant (SYBR Green; Molecular Probes) and an impermeant (propidium iodide) probe and to take advantage of the energy transfer which occurs between them when both probes are staining nucleic acids. A full quenching of the permeant probe fluorescence by the impermeant probe will point to cells with a compromised membrane, a partial quenching will indicate cells with a slightly damaged membrane, and a lack of quenching will characterize intact membrane cells identified as viable. In the present study, this approach has been adapted to bacteria in freshwater and marine waters of the Mediterranean region. It is fast and easy to use and shows that a large fraction of bacteria with low DNA content can be composed of viable cells. Admittedly, limitations stem from the unknown behavior of unidentified species present in natural environments which may depart from the established permeability properties with respect to the fluorescing dyes.

Elliptic fourier analysis of cell and nuclear shapes

The elliptic Fourier analysis (EFA) is proposed to characterize the cell and nuclear shape. The principal feature of this method is that it decomposes shapes with a closed contour into subshapes each of which maintains a closed contour. A set of homogeneous, nonredundant descriptors, independent of the contour rotation and translation, is computed from the elliptic Fourier coefficients. These descriptors also account for the contour size and resolution. The paired analysis of the cell and nuclear shape provides an exhaustive and accurate definition of the nucleoplasmic configuration.