Management of acute respiratory failure in interstitial lung diseases: overview and clinical insights

High-Flow Nasal Cannula System in Respiratory Failure Associated with Interstitial Lung Diseases: A Systematic Review and Narrative Synthesis

Background: High-flow nasal cannula (HFNC) therapy has emerged as a promising treatment modality for interstitial lung disease (ILD)-related respiratory failure. This systematic review aims to evaluate the efficacy and safety of HFNC therapy in patients with ILDs. Methods: A comprehensive literature search was conducted using major electronic databases to identify relevant studies investigating the use of HFNC therapy in ILD patients with respiratory failure. Outcome measures of interest included improvements in oxygenation, dyspnea relief, respiratory rate control, hospital length of stay, and mortality. Results: Twelve studies were analyzed with an overall population of 715 patients included. Idiopathic Pulmonary Fibrosis (IPF) was the most prevalent type of ILD. Evaluated clinical settings were acute (7 studies), chronic (2 studies), and end-stage (3 studies) ILDs. The HFNC as a support for acute respiratory failure seems not inferior to non-invasive ventilation while offering better comfort and patient's perception. Poor data are available about use in chronic/long-term or rehabilitative settings. In end of life/palliative care, an HFNC might improve quality of life. Despite the promising results, further research is warranted to establish optimal HFNC protocols, identify patient subgroups most likely to benefit, and explore long-term outcomes. Conclusions: Overall, the HFNC appears to be a valuable therapeutic option for managing respiratory failure in ILD patients, offering potential improvements in oxygenation and symptom relief.

[Palliative aspects in clinical acute and emergency medicine as well as intensive care medicine : Consensus paper of the DGIIN, DGK, DGP, DGHO, DGfN, DGNI, DGG, DGAI, DGINA and DG Palliativmedizin]

The integration of palliative medicine is an important component in the treatment of various advanced diseases. While a German S3 guideline on palliative medicine exists for patients with incurable cancer, a recommendation for non-oncological patients and especially for palliative patients presenting in the emergency department or intensive care unit is missing to date. Based on the present consensus paper, the palliative care aspects of the respective medical disciplines are addressed. The timely integration of palliative care aims to improve quality of life and symptom control in clinical acute and emergency medicine as well as intensive care.

Effect of noninvasive respiratory support on interstitial lung disease with acute respiratory failure: A systematic review and meta-analysis

Background

Primary studies have demonstrated the effectiveness of noninvasive respiratory supports, including noninvasive positive pressure ventilation (NIPPV) and high flow nasal cannula (HFNC), for improving oxygenation and ventilation in patients with interstitial lung diseases (ILDs) and acute respiratory failure (ARF). These studies have not been synthesized and are not included in current practice guidelines. This systematic review with meta-analysis synthesizes studies that compared the effectiveness of NIPPV, HFNC and conventional oxygen therapy (COT) for improving oxygenation and ventilation in ILD patients with ARF.

Methods

MEDLINE, EMBASE and the Cochrane Library searches were conducted from inception to August 2023. An additional search of relevant primary literature and review articles was also performed. A random effects model was used to estimate the PF ratio (ratio of arterial oxygen partial pressure to fractional inspired oxygen), PaCO2 (partial pressure of carbon dioxide), mortality, intubation rate and hospital length of stay.

Results

Ten studies were included in the systematic review and meta-analysis. Noninvasive respiratory supports demonstrated a significant improvement in PF ratio compared to conventional oxygen therapy (COT); the mean difference was 55.92 (95% CI [18.85-92.99]; p=0.003). Compared to HFNC, there was a significant increase in PF ratio in NIPPV (mean difference 0.45; 95% CI [0.12-0.79]; p=0.008). There were no mortality and intubation rate benefits when comparing NIPPV and HFNC; the mean difference was 1.1; 95% CI [0.83-1.44]; p=0.51 and 1.86; 95% CI [0.42-8.33]; p=0.42, respectively. In addition, there was a significant decrease in hospital length of stay in HFNC compared to NIPPV (mean difference 9.27; 95% Cl [1.45 - 17.1]; p=0.02).

Conclusions

Noninvasive respiratory supports might be an alternative modality in ILDs with ARF. NIPPV demonstrated a potential to improve the PF ratio compared to HFNC. There was no evidence to support the benefit of NIPPV or HFNC in terms of mortality and intubation rate.

[Non-invasive Mechanical Ventilation in Acute Respiratory Failure. Clinical Practice Guidelines - on behalf of the German Society of Pneumology and Ventilatory Medicine]

The guideline update outlines the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.Non-invasive ventilation (NIV) has a high value in therapy of hypercapnic acute respiratory failure, as it significantly reduces the length of ICU stay and hospitalization as well as mortality.Patients with cardiopulmonary edema and acute respiratory failure should be treated with continuous positive airway pressure (CPAP) and oxygen in addition to necessary cardiological interventions. This should be done already prehospital and in the emergency department.In case of other forms of acute hypoxaemic respiratory failure with only mild or moderately disturbed gas exchange (PaO2/FiO2 > 150 mmHg) there is no significant advantage or disadvantage compared to high flow nasal oxygen (HFNO). In severe forms of ARDS NIV is associated with high rates of treatment failure and mortality, especially in cases with NIV-failure and delayed intubation.NIV should be used for preoxygenation before intubation. In patients at risk, NIV is recommended to reduce extubation failure. In the weaning process from invasive ventilation NIV essentially reduces the risk of reintubation in hypercapnic patients. NIV is regarded useful within palliative care for reduction of dyspnea and improving quality of life, but here in concurrence to HFNO, which is regarded as more comfortable. Meanwhile NIV is also recommended in prehospital setting, especially in hypercapnic respiratory failure and pulmonary edema.With appropriate monitoring in an intensive care unit NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency.

Integrative analyses for the identification of idiopathic pulmonary fibrosis-associated genes and shared loci with other diseases

BACKGROUND

Although genome-wide association studies (GWAS) have identified many genomic regions associated with idiopathic pulmonary fibrosis (IPF), the causal genes and functions remain largely unknown. Many single-cell expression data have become available for IPF, and there is increasing evidence suggesting a shared genetic basis between IPF and other diseases.

METHODS

We conducted integrative analyses to improve the power of GWAS. First, we calculated global and local genetic correlations to identify IPF genetically associated traits and local regions. Then, we prioritised candidate genes contributing to local genetic correlation. Second, we performed transcriptome-wide association analysis (TWAS) of 44 tissues to identify candidate genes whose genetically predicted expression level is associated with IPF. To replicate our findings and investigate the regulatory role of the transcription factors (TF) in identified candidate genes, we first conducted the heritability enrichment analysis in TF binding sites. Then, we examined the enrichment of the TF target genes in cell-type-specific differentially expressed genes (DEGs) identified from single-cell expression data of IPF and healthy lung samples.

FINDINGS

We identified 12 candidate genes across 13 genomic regions using local genetic correlation, including the POT1 locus (p value=0.00041), which contained variants with protective effects on lung cancer but increasing IPF risk. We identified another 13 novel genes using TWAS. Two TFs, MAFK and SMAD2, showed significant enrichment in both partitioned heritability and cell-type-specific DEGs.

INTERPRETATION

Our integrative analysis identified new genes for IPF susceptibility and expanded the understanding of the complex genetic architecture and disease mechanism of IPF.

Repurposing of carvedilol to alleviate lung fibrosis in rats: Repressing of TGF-β1/α-SMA/Smad2/3 and STAT3 gene expressions

Idiopathic pulmonary fibrosis (IPF) is the most widely studied interstitial lung disease. IPF eventually leads to respiratory insufficiency, lung cancer, and death. Carvedilol (CAR) is a third-generation β-adrenergic receptor antagonist with α1-blocking effect. CAR demonstrates antifibrotic activities in various experimental models of organ fibrosis.

AIMS

This work is designed to explore the possible alleviating effects of CAR on bleomycin (BLM)-induced lung fibrosis in rats.

MAIN METHODS

The BLM rat model of lung fibrosis was achieved by intratracheal delivery of a single dose of 5 mg/kg of BLM. Seven days following BLM injection, either prednisolone or CAR was orally administered at doses of 10 mg/kg once daily for 21 days to rats. The actions of CAR were evaluated by lung oxidant/antioxidant parameters, protein concentration and total leucocyte count (TLC) in bronchoalveolar lavage fluid (BALF), fibrosis regulator-related genes along with the coexistent lung histological changes.

KEY FINDINGS

CAR effectively decreased lung malondialdehyde level, increased superoxide dismutase activity, declined both protein concentration and TLC in BALF, downregulated TGF-β1/α-SMA/Smad2/3 and STAT3 gene expressions, and repaired the damaged lung tissues.

SIGNIFICANCE

CAR conferred therapeutic potential against BLM-induced lung fibrosis in rats, at least in part, to its antioxidant, anti-inflammatory, and antifibrotic activities. CAR could be utilized as a prospective therapeutic option in patients with lung fibrosis in clinical practice.

Peptide-guided delivery improves the therapeutic efficacy and safety of glucocorticoid drugs for treating acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are life-threatening conditions with excessive inflammation in the lung. Glucocorticoids had been widely used for ALI/ARDS, but their clinical benefit remains unclear. Here, we tackled the problem by conjugating prednisolone (PSL) with a targeting peptide termed CRV. Systemically administered CRV selectively homes to the inflamed lung of a murine ALI model, but not healthy organs or the lung of healthy mice. The expression of the CRV receptor, retinoid X receptor β, was elevated in the lung of ALI mice and patients with interstitial lung diseases, which may be the basis of CRV targeting. We then covalently conjugated PSL and CRV with a reactive oxygen species (ROS)-responsive linker in the middle. While being intact in blood, the ROS linker was cleaved intracellularly to release PSL for action. In vitro, CRV-PSL showed an anti-inflammatory effect similar to that of PSL. In vivo, CRV conjugation increased the amount of PSL in the inflamed lung but reduced its accumulation in healthy organs. Accordingly, CRV-PSL significantly reduced lung injury and immune-related side effects elsewhere. Taken together, our peptide-based strategy for targeted delivery of glucocorticoids for ALI may have great potential for clinical translation.

Interstitial Lung Disease: A Focused Review for the Emergency Clinician

BACKGROUND

Interstitial lung disease (ILD) is a group of restrictive pulmonary diseases associated with diffuse interstitial and parenchymal inflammation. Patients can present to the emergency department with severe exacerbation.

OBJECTIVE

This narrative review provides emergency clinicians with the most recent evidence concerning acute exacerbation of ILD (AE-ILD).

DISCUSSION

AE-ILD can present as acute respiratory distress in a patient with a pre-existing ILD diagnosis or as a de novo presentation of ILD, and is associated with significant morbidity and mortality. A variety of underlying triggers may result in AE-ILD. Emergency clinicians must first assess for extraneous causes of respiratory decompensation prior to diagnosing AE-ILD. For a de novo presentation of ILD, emergency physicians should also assess for possible reversible causes. AE-ILD is managed with systemic steroids, immunosuppressants, intravenous antibiotics, supplemental oxygen, and extracorporeal membrane oxygenation in severe cases. Given the high mortality rates in the absence of lung transplantation, early referral to transplant centers is essential to increase chances of survival.

CONCLUSIONS

Emergency clinician knowledge of AE-ILD can improve the evaluation and management of these patients.

Idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis is defined as a chronic progressive fibrosing interstitial pneumonia of unknown etiology. There are intrinsic and extrinsic risk factors that could favor the development of the disease in individuals with a genetic predisposition. The diagnosis is made by characteristic radiological and/or histological findings on high-resolution computed tomography and lung biopsy, respectively, in the absence of a specific identifiable cause. The median survival of the disease for patients without treatment is 3-5years from the onset of symptoms, although its natural history is variable and unpredictable. Currently, there are two antifibrotic drugs that reduce disease progression. The multidisciplinary approach will consider the nutritional and emotional status, physical conditioning, and treatment of comorbidities, as well as lung transplantation and palliative care in advanced stages. The following article reviews the fundamental aspects for the diagnosis and treatment of idiopathic pulmonary fibrosis.

IPF Respiratory Symptoms Management — Current Evidence

Idiopathic pulmonary fibrosis (IPF) is a progressive, chronic disease of the lungs which is characterized by heavy symptom burden, especially in the last year of life. Despite recently established anti-fibrotic treatment IPF prognosis is one of the worst among interstitial lung diseases. In this review available evidence regarding pharmacological and non-pharmacological management of the main IPF symptoms, dyspnea and cough, is presented.

Inpatient Management of the Acutely Decompensating Lung Transplant Candidate

Lung allocation in the US changed nearly 15 years ago from time accrued on the waiting list to disease severity and likelihood of posttransplant survival, represented by the lung allocation score (LAS). Notably, the risk of death within a year plays a stronger role on the score calculation than posttransplant survival. While this change was associated with the intended decrease in waitlist mortality (most recently reported at 14.6%), it was predictable that transplant teams would have to care for increasingly older and complex candidates and recipients. This urgency-based allocation also led centers to routinely consider transplanting patients with higher acuity, often hospitalized and, not infrequently, in the intensive care unit (ICU). According to the Scientific Registry for Transplant Recipients, from 2009 to 2019, the proportion of lung recipients hospitalized and those admitted to the ICU at the time of transplant increased from 18.9% to 26.8% and from 9.2% to 16.5%, respectively..

6-Gingerol, a functional polyphenol of ginger, reduces pulmonary fibrosis by activating Sirtuin1

Pulmonary fibrosis in general is the final common outcome of various interstitial lung diseases. In recent years, the incidence of pulmonary fibrosis has been rising with poor prognosis. 6-gingerol is deemed as a functional polyphenol of ginger. The aim of the present study was to investigate the effect of 6-gingerol, on pulmonary fibrosis. Mice were randomly divided into four groups: control, bleomycin, bleomycin + 6-gingerol 100 mg/kg, bleomycin + 6-gingerol 250 mg/kg, and the survival rates of the groups were recorded. Pathological and fibrotic changes in the lungs were identified by H&E and Masson staining, respectively. The levels of hydroxyproline and protein deposited in lung tissues were then, respectively, determined by colorimetry and western blotting. Subsequently, the proportion of cells and inflammatory factors in the alveolar lavage fluid were estimated. Following the identification of the possibility of Sirtuin1 (SIRT1) in the pharmacological mechanism through molecular docking and western blotting, human embryonic lung fibroblasts MRC-5 were treated with TGF-β1 and SIRT1 inhibitor to study the role of SIRT1 in the regulatory effect of 6-gingerol. From the results, 6-gingerol was found to increase the survival rate of mice and reduce lung pathology and fibrosis in mice. And, it significantly reduced the levels of hydroxyproline and the proteins deposited in lung tissues. Moreover, the number of neutrophils, basophils, monocytes, and the levels of inflammatory factors in the alveolar lavage fluid were also reduced. SIRT1 inhibitor blocked the function of 6-gingerol to inhibit fibrosis. To sum up, 6-gingerol relieves pulmonary fibrosis via activating SIRT1. This finding expands the pharmacological effect of 6-gingerol, and it is expected to advance the development of treatments for pulmonary fibrosis.

Acute exacerbation of interstitial lung disease in the intensive care unit

Acute exacerbations of interstitial lung disease (AE-ILD) represent an acute, frequent and often highly morbid event in the disease course of ILD patients. Admission in the intensive care unit (ICU) is very common and the need for mechanical ventilation arises early. While non-invasive ventilation has shown promise in staving off intubation in selected patients, it is unclear whether mechanical ventilation can alter the exacerbation course unless it is a bridge to lung transplantation. Risk stratification using clinical and radiographic findings, and early palliative care involvement, are important in ICU care. In this review, we discuss many of the pathophysiological aspects of AE-ILD and raise the hypothesis that ventilation strategies used in acute respiratory distress syndrome might be implemented in AE-ILD. We present possible decision-making and management algorithms that can be used by the intensivist when caring for these patients.

Acute Exacerbation of Idiopathic Pulmonary Fibrosis

Acute exacerbation is a major cause of morbidity and mortality in patients with idiopathic pulmonary fibrosis. Although the real nature of it is still not clear and there is no proven effective therapy, progress has been made since the consensus definition and diagnostic criteria were proposed. The trial results of several new innovative therapies in idiopathic pulmonary fibrosis have suggested a potential for benefit in acute exacerbation of idiopathic pulmonary fibrosis, leading to double blind randomized clinical trials in this area. This article reviews the present knowledge on acute exacerbation of idiopathic pulmonary fibrosis, focusing on the triggering factors and treatment.

Interstitial lung disease on the acute take for the non-respiratory physician

Interstitial lung diseases (ILDs) are a heterogeneous group of diseases characterised by varying degrees of fibrotic and/or inflammatory abnormalities of the lung parenchyma. Management of ILD is often challenging for non-respiratory physicians. We discuss the respiratory assessment and management of patients with ILD presenting with acute breathlessness on the acute take, including acute exacerbations of ILD.

Efficacy of extracorporeal membrane oxygenation for acute respiratory failure with interstitial lung disease: a case control nationwide dataset study in Japan

Background

Whether acute respiratory failure in patients with interstitial lung disease is reversible remains uncertain. Consequently, indications for extracorporeal membrane oxygenation in these patients are still controversial, except as a bridge to lung transplantation. The objective of this study was to clarify in-hospital mortality and prognostic factors in interstitial lung disease patients undergoing extracorporeal membrane oxygenation.

Methods

In this case–control study using the Japanese Diagnosis Procedure Combination database, hospitalized interstitial lung disease patients receiving invasive mechanical ventilation and extracorporeal membrane oxygenation from 2010 to 2017 were reviewed. Patients’ characteristics and treatment regimens were compared between survivors and non-survivors to identify prognostic factors. To avoid selection biases, patients treated with extracorporeal membrane oxygenation as a bridge to lung transplantation were excluded.

Results

A total of 164 interstitial lung disease patients receiving extracorporeal membrane oxygenation were included. Their in-hospital mortality was 74.4% (122/164). Compared with survivors, non-survivors were older and received high-dose cyclophosphamide, protease inhibitors, and antifungal drugs more frequently, but macrolides and anti-influenza drugs less frequently. On multivariate analysis, the following factors were associated with in-hospital mortality: advanced age (odds ratio [OR] 1.043; 95% confidence interval [CI] 1.009–1.078), non-use of macrolides (OR 0.305; 95% CI 0.134–0.698), and use of antifungal drugs (OR 2.416; 95% CI 1.025–5.696).

Conclusions

Approximately three-quarters of interstitial lung disease patients undergoing extracorporeal membrane oxygenation died in hospital. Moreover, advanced age, non-use of macrolides, and use of antifungal drugs were found to correlate with a poor prognosis.

Outcome and prognostic factors of interstitial lung disease patients with acute respiratory failure in the intensive care unit

Background:

There are few studies reporting the clinical characteristics and outcomes of interstitial lung disease (ILD) patients with acute respiratory failure (ARF). The goal of this study is to investigate the clinical features, management, mortality, and associated factors in ILD patients with ARF requiring mechanical ventilation (MV).

Methods:

This was a retrospective, observational study conducted in a 24-bed intensive care unit (ICU) of a medical center in Taiwan during a 3-year period. Patients admitted to the ICU with a diagnosis of ILD with ARF needing MV were included for analysis. Patient characteristics, including demographics, critical-illness factors, and outcome data, were collected and analyzed.

Results:

A total of 82 patients with ILD who developed ARF were admitted to the ICU during the study period. At the onset of ARF, 38 patients received invasive MV, while 44 patients were treated with noninvasive MV. Overall in-hospital mortality was 65.9%, and 90-day and 1-year mortality were 69.5% and 76.8%, respectively. The independent risk factors for in-hospital mortality were worse oxygenation on days 5 and 7 after the onset of ARF. Invasive MV patients had significantly lower albumin levels, had higher Acute Physiology and Chronic Health Evaluation (APACHE) II scores at the onset of ARF, and received more vasopressors, sedatives, and corticosteroid pulse therapy during hospitalization compared with noninvasive MV patients.

Conclusion:

High in-hospital and long-term mortality rates were observed in ILD patients with ARF requiring MV. Poor oxygenation during hospitalization could serve as a predictive factor of poor prognosis.

The reviews of this paper are available via the supplemental material section.

Critical Care of Patients With Cardiopulmonary Complications of Sarcoidosis

Sarcoidosis is a systemic inflammatory disease defined by the presence of aberrant granulomas affecting various organs. Due to its multisystem involvement, care of patients with established sarcoidosis becomes challenging, especially in the intensive care setting. While the lungs are typically involved, extrapulmonary manifestations also occur either concurrently or exclusively within a significant proportion of patients, complicating diagnostic and management decisions. The scope of this review is to focus on what considerations are necessary in the evaluation and management of patients with known sarcoidosis and their associated complications within a cardiopulmonary and critical care perspective.

Precision medicine in acute respiratory distress syndrome: workshop report and recommendations for future research

Acute respiratory distress syndrome (ARDS) is a devastating critical illness that can be triggered by a wide range of insults and remains associated with a high mortality of around 40%. The search for targeted treatment for ARDS has been disappointing, possibly due to the enormous heterogeneity within the syndrome. In this perspective from the European Respiratory Society research seminar on "Precision medicine in ARDS", we will summarise the current evidence for heterogeneity, explore the evidence in favour of precision medicine and provide a roadmap for further research in ARDS. There is evident variation in the presentation of ARDS on three distinct levels: 1) aetiological; 2) physiological and 3) biological, which leads us to the conclusion that there is no typical ARDS. The lack of a common presentation implies that intervention studies in patients with ARDS need to be phenotype aware and apply a precision medicine approach in order to avoid the lack of success in therapeutic trials that we faced in recent decades. Deeper phenotyping and integrative analysis of the sources of variation might result in identification of additional treatable traits that represent specific pathobiological mechanisms, or so-called endotypes.

Modulating the Barrier Function of Human Alveolar Epithelial (hAELVi) Cell Monolayers as a Model of Inflammation

The incidence of inflammatory lung diseases such as acute respiratory distress syndrome (ARDS) remains an important problem, particularly in the present time with the Covid-19 pandemic. However, an adequate in vitro test system to monitor the barrier function of the alveolar epithelium during inflammation and for assessing anti-inflammatory drugs is urgently needed. Therefore, we treated human Alveolar Epithelial Lentivirus-immortalised cells (hAELVi cells) with the pro-inflammatory cytokines TNF-α (25 ng/ml) and IFN-γ (30 ng/ml), in the presence or absence of hydrocortisone (HC). While TNF-α and IFN-γ are known to reduce epithelial barrier properties, HC could be expected to protect the barrier function and result in an anti-inflammatory effect. We investigated the impact of anti-inflammatory/inflammatory treatment on transepithelial electrical resistance (TEER) and the apparent permeability coefficient (P app) of the low permeability marker sodium fluorescein (NaFlu). After incubating hAELVi cells for 48 hours with a combination of TNF-α and IFN-γ, there was a significant decrease in TEER and a significant increase in the P app. The presence of HC maintained the TEER values and barrier properties, so that no significant P app change was observed. By using hAELVi cells to study anti-inflammatory drugs in vitro, the need for animal experiments could be reduced and pulmonary drug development accelerated.

Corticosteroids are associated with reduced skeletal muscle function in interstitial lung disease patients with mild dyspnea

BACKGROUND

Interstitial lung diseases (ILDs) patients receiving steroid treatment tend to be immobilized by dyspnea and muscle weakness as the disease progresses. We therefore expected that steroid treatment for ILDs would have a greater effect on muscle function under severe dyspnea. To test this hypothesis, we evaluated whether the effect of corticosteroid treatment on peripheral muscle force and exercise capacity varied according to patients' dyspnea severity.

METHODS

In this retrospective cross-sectional study of 87 ILD patients enrolled between 2008 and 2017, quadriceps force (QF), handgrip force (HF), and 6-min walk distance (6 MWD) were compared between a low (grades 0-2) and a high (grades 3-4) modified-Medical Research Council (mMRC) dyspnea scale score group.

RESULTS

In patients with lower levels of dyspnea, corticosteroid treatments were associated with lower QF and HF (20.0 vs. 30.0 kgf, p = 0.01; 22.5 vs. 28.4 kgf, p = 0.03, respectively) values; however, no significant differences were observed between the corticosteroid and control subgroups in the high mMRC group (QF: 18.5 vs. 17.3 kgf, p = 0.64; HF: 21.0 vs. 17.1 kgf, p = 0.24, respectively). Analysis of covariance indicated that both corticosteroid treatment and mMRC dyspnea scale interacted with QF, HF, and 6 MWD. The effects of the corticosteroid treatment varied according to the level of dyspnea (interaction β = 7.52, p = 0.034; interaction β = 8.78, p = 0.048; interaction β = 131.08, p < 0.001).

CONCLUSIONS

Muscle weakness and exercise capacity in ILD patients in the low mMRC group were associated with corticosteroid treatment.

A Pathophysiological Perspective on COVID-19's Lethal Complication: From Viremia to Hypersensitivity Pneumonitis-like Immune Dysregulation

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the coronavirus responsible for our recent coronavirus disease 2019 pandemic, is driving a lung immunopathology that strongly resembles a severe form of hypersensitivity pneumonitis (HP). A review of recent Severe acute respiratory syndrome-related coronavirus (SARS-CoV) and SARS-CoV-2 medical reports, as well as described characteristics of HP, lead us to postulate a theory for SARS-CoV-2 severe disease. We propose that the novel SARS-CoV-2 can act as a trigger and substrate of an HP-like severe immune reaction especially in genetically vulnerable individuals in addition to those with immune senescence and dysregulation. Accordingly, the purpose of our letter is to shift the emphasis of concern surrounding immune activity from viral infection to an HP-like severe immune reaction. We review similarities in disease presentation between infection and allergy, relevant immunopathology, and outline phases of SARS-CoV-2 disease with perspectives on therapy and critical care. Altogether, the favored course is to begin treatments that address the disease at the earliest phase before immune dysregulation leading to uncontrolled pulmonary inflammation.

Acute exacerbation of idiopathic pulmonary fibrosis: international survey and call for harmonisation

Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is an often deadly complication of IPF. No focussed international guidelines for the management of AE-IPF exist. The aim of this international survey was to assess the global variability in prevention, diagnostic and treatment strategies for AE-IPF.

Pulmonologists with ILD expertise were invited to participate in a survey designed by an international expert panel.

509 pulmonologists from 66 countries responded. Significant geographical variability in approaches to manage AE-IPF was found. Common preventive measures included antifibrotic drugs and vaccination. Diagnostic differences were most pronounced regarding use of Krebs von den Lungen-6 and viral testing, while high-resolution computed tomography, brain natriuretic peptide and D-dimer are generally applied. High-dose steroids are widely administered (94%); the use of other immunosuppressant and treatment strategies is highly variable. Very few (4%) responders never use immunosuppression. Antifibrotic treatments are initiated during AE-IPF by 67%. Invasive ventilation or extracorporeal membrane oxygenation are mainly used as a bridge to transplantation. Most physicians educate patients comprehensively on the severity of AE-IPF (82%) and consider palliative care (64%).

Approaches to the prevention, diagnosis and treatment of AE-IPF vary worldwide. Global trials and guidelines to improve the prognosis of AE-IPF are needed.

Acute Respiratory Failure in Interstitial Lung Disease Complicated by Pulmonary Hypertension

Interstitial lung disease represents a group of diffuse parenchymal lung diseases with overwhelming morbidity and mortality when complicated by acute respiratory failure. Recently, trials investigating outcomes and their determinants have provided insight into these high mortality rates. Pulmonary hypertension is a known complication of interstitial lung disease and there is high prevalence in idiopathic pulmonary fibrosis, connective tissue disease, and sarcoidosis subtypes. Interstitial lung disease associated pulmonary hypertension has further increased mortality with acute respiratory failure, and there is limited evidence to guide management. This review describes investigations and management of interstitial lung disease associated acute respiratory failure complicated by pulmonary hypertension. Despite the emerging attention on interstitial lung disease associated acute respiratory failure and the influence of pulmonary hypertension, critical care management remains a clinical and ethical challenge.

High-flow nasal cannula oxygen therapy to treat acute respiratory failure in patients with acute exacerbation of idiopathic pulmonary fibrosis

Background:

Some patients with idiopathic pulmonary fibrosis (IPF) develop acute exacerbation (AE-IPF) leading to severe acute respiratory failure (ARF); despite conventional supportive therapy, the mortality rate remains extremely high. The aim of this study was to assess how a treatment algorithm incorporating high-flow nasal cannula (HFNC) oxygen therapy affects the short-term mortality of patients with AE-IPF who develop ARF.

Method and design:

A retrospective cohort analysis was conducted.

Patients and interventions:

The study consisted of 17 patients with AE-IPF admitted to a respiratory intensive care unit (RICU) for ARF managed using a treatment algorithm incorporating HFNC. The outcome measure was mortality rate during their stay in the RICU.

Results:

Implementation of the treatment algorithm led to a successful outcome in nine patients and to a negative one in eight patients (47.1%) who died within 39 days of being admitted to the RICU. The survival rate was 70.6% (±0.1 %) at 15 days, 52.9% (±0.1%) at 30 days, 35.3% (±0.1%) at 90 days, and 15.6% (±9.73 %) at 365 days. Overall, 4 out of 10 patients who did not respond to conventional oxygen therapy showed a satisfactory response to HFNC.

Conclusions:

Short-term mortality fell to below 50% when a treatment algorithm incorporating HFNC was implemented in a group of patients with AE-IPF admitted to a RICU for ARF. Patients not responding to conventional oxygen therapy seemed to benefit from HFNC.

The reviews of this paper are available via the supplementary material section.

De novo lung biofabrication: clinical need, construction methods, and design strategy

Chronic lung disease is the 4th leading cause of death in the United States. Due to a shortage of donor lungs, alternative approaches to support failing, native lungs have been attempted, including mechanical ventilation and various forms of artificial lungs. However, each of these support methods causes significant complications when used for longer than a few days and are thus not capable of long-term support. For artificial lungs, complications arise due to interactions between the artificial materials of the device and the blood of the recipient. A potential new approach is the fabrication of lungs from biological materials, such that the gas exchange membranes provide a more biomimetic blood-contacting interface. Recent advancements with three-dimensional, soft-tissue biofabrication methods and the engineering of thin, basement membranes demonstrate the potential of fabricating a lung scaffold from extracellular matrix materials. This scaffold could then be seeded with endothelial and epithelial cells, matured within a bioreactor, and transplanted. In theory, this fully biological lung could provide improved, long-term biocompatibility relative to artificial lungs, but significant work is needed to perfect the organ design and construction methods. Like artificial lungs, biofabricated lungs do not need to follow the shape and structure of a native lung, allowing for simpler manufacture. However, various functional requirements must still be met, including stable, efficient gas exchange for a period of years. Design decisions depend on the disease state, how the organ is implanted, and the latest biofabrication methods available in a rapidly evolving field.

Management of Chronic Respiratory Failure in Interstitial Lung Diseases: Overview and Clinical Insights

Interstitial lung diseases (ILDs) may be complicated by chronic respiratory failure (CRF), especially in the advanced stages. Aim of this narrative review is to evaluate the current evidence in management of CRF in ILDs. Many physiological mechanisms underlie CRF in ILDs, including lung restriction, ventilation/perfusion mismatch, impaired diffusion capacity and pulmonary vascular damage. Intermittent exertional hypoxemia is often the initial sign of CRF, evolving, as ILD progresses, into continuous hypoxemia. In the majority of the cases, the development of CRF is secondary to the worsening of the underlying disease; however, associated comorbidities may also play a role. When managing CRF in ILDs, the need for pulmonary rehabilitation, the referral to lung transplant centers and palliative care should be assessed and, if necessary, promptly offered. Long-term oxygen therapy is commonly prescribed in case of resting or exertional hypoxemia with the purpose to decrease dyspnea and improve exercise tolerance. High-Flow Nasal Cannula oxygen therapy may be used as an alternative to conventional oxygen therapy for ILD patients with severe hypoxemia requiring both high flows and high oxygen concentrations. Non-Invasive Ventilation may be used in the chronic setting for palliation of end-stage ILD patients, although the evidence to support this application is very limited.

Risk factors for mortality and mortality rates in interstitial lung disease patients in the intensive care unit

Data on interstitial lung disease (ILD) outcomes in the intensive care unit (ICU) is of limited value due to population heterogeneity. The aim of this study was to examine risk factors for mortality and ILD mortality rates in the ICU.We performed a systematic review using five databases. 50 studies were identified and 34 were included: 17 studies on various aetiologies of ILD (mixed-ILD) and 17 on idiopathic pulmonary fibrosis (IPF). In mixed-ILD, elevated APACHE score, hypoxaemia and mechanical ventilation are risk factors for mortality. No increased mortality was found with steroid use. Evidence is inconclusive on advanced age. In IPF, evidence is inconclusive for all factors except mechanical ventilation and hypoxaemia. The overall in-hospital mortality was available in 15 studies on mixed-ILD (62% in 2001-2009 and 48% in 2010-2017) and 15 studies on IPF (79% in 1993-2004 and 65% in 2005-2017). Follow-up mortality rate at 1 year ranged between 53% and 100%.Irrespective of ILD aetiology, mechanical ventilation is associated with increased mortality. For mixed-ILD, hypoxaemia and APACHE scores are also associated with increased mortality. IPF has the highest mortality rate among ILDs, but since 1993 the rate appears to be declining. Despite improving in-hospital survival, overall mortality remains high.

Comorbidities, Complications and Non-Pharmacologic Treatment in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and fatal disease. The treatment is challenging and nowadays a comprehensive approach based not only in pharmacological strategies is necessary. Identification and control of comorbidities, non-pharmacological treatment, prevention and management of exacerbations as well as other areas of care (social, psychological) are fundamental for a holistic management of IPF. Gastroesophageal reflux, pulmonary hypertension, obstructive sleep apnea, combined with emphysema, lung cancer and cardiovascular involvement are the main comorbidities associated with IPF. Non-pharmacological treatment includes the use of oxygen in patients with rest or nocturnal hypoxemia and other support therapies such as non-invasive ventilation or even a high-flow nasal cannula to improve dyspnea. In some patients, lung transplant should be considered as this enhances survival. Pulmonary rehabilitation can add benefits in outcomes such control of dyspnea, exercise capacity distance and, overall, improve the quality of life; therefore it should be considered in patients with IPF. Also, multidisciplinary palliative care programs could help with symptom control and psychological support, with the aim of maintaining quality of life during the whole process of the disease. This review intends to provide clear information to help those involved in IPF follow up to improve patients’ daily care.