Physiological effects of lung-protective ventilation in patients with lung fibrosis and usual interstitial pneumonia pattern versus primary ARDS: a matched-control study.

BACKGROUND: Although patients with interstitial pneumonia pattern (ILD-UIP) and acute exacerbation (AE) leading to severe acute respiratory failure may require invasive mechanical ventilation (MV), physiological data on lung mechanics during MV are lacking. We aimed at describing the physiological effect of lung-protective ventilation in patients with AE-ILD-UIP compared with primary ARDS. METHODS: Partitioned lung and chest wall mechanics were assessed in a series of AE-ILD-UIP patients matched 1:1 with primary ARDS as controls (based on BMI and PaO2/FiO2 ratio). Three PEEP levels (zero = ZEEP, 4-8 cmH2O = PEEPLOW, and titrated to achieve positive end-expiratory transpulmonary pressure PL,EE = PEEPTITRATED) were used for measurements. RESULTS: Ten AE-ILD-UIP patients and 10 matched ARDS were included. In AE-ILD-UIP median PL,EE at ZEEP was - 4.3 [- 7.6- - 2.3] cmH2O and lung elastance (EL) 44 [40-51] cmH2O/L. At PEEPLOW, PL,EE remained negative and EL did not change (p = 0.995) versus ZEEP. At PEEPTITRATED, PL,EE increased to 0.8 [0.3-1.5] cmH2O and EL to 49 [43-59] (p = 0.004 and p < 0.001 compared to ZEEP and PEEPLOW, respectively). ΔPL decreased at PEEPLOW (p = 0.018) and increased at PEEPTITRATED (p = 0.003). In matched ARDS control PEEP titration to obtain a positive PL,EE did not result in significant changes in EL and ΔPL. CONCLUSIONS: In mechanically ventilated AE-ILD-UIP patients, differently than in patients with primary ARDS, PEEP titrated to obtain a positive PL,EE significantly worsened lung mechanics.

Molecular Biology and Therapeutic Targets of Primitive Tracheal Tumors: Focus on Tumors Derived by Salivary Glands and Squamous Cell Carcinoma.

Primary tracheal tumors are rare, constituting approximately 0.1-0.4% of malignant diseases. Squamous cell carcinoma (SCC) and adenoid cystic carcinoma (ACC) account for about two-thirds of these tumors. Despite most primary tracheal cancers being eligible for surgery and/or radiotherapy, unresectable, recurrent and metastatic tumors may require systemic treatments. Unfortunately, the poor response to available chemotherapy as well as the lack of other real therapeutic alternatives affects the quality of life and outcome of patients suffering from more advanced disease. In this condition, target therapy against driver mutations could constitute an alternative to chemotherapy, and may help in disease control. The past two decades have seen extraordinary progress in developing novel target treatment options, shifting the treatment paradigm for several cancers such as lung cancer. The improvement of knowledge regarding the genetic and biological alterations, of major primary tracheal tumors, has opened up new treatment perspectives, suggesting the possible role of biological targeted therapies for the treatment of these rare tumors. The purpose of this review is to outline the state of knowledge regarding the molecular biology, and the preliminary data on target treatments of the main primary tracheal tumors, focusing on salivary-gland-derived cancers and squamous cell carcinoma.

Nasal pressure swings as the measure of inspiratory effort in spontaneously breathing patients with de novo acute respiratory failure.

BACKGROUND: Excessive inspiratory effort could translate into self-inflicted lung injury, thus worsening clinical outcomes of spontaneously breathing patients with acute respiratory failure (ARF). Although esophageal manometry is a reliable method to estimate the magnitude of inspiratory effort, procedural issues significantly limit its use in daily clinical practice. The aim of this study is to describe the correlation between esophageal pressure swings (ΔPes) and nasal (ΔPnos) as a potential measure of inspiratory effort in spontaneously breathing patients with de novo ARF. METHODS: From January 1, 2021, to September 1, 2021, 61 consecutive patients with ARF (83.6% related to COVID-19) admitted to the Respiratory Intensive Care Unit (RICU) of the University Hospital of Modena (Italy) and candidate to escalation of non-invasive respiratory support (NRS) were enrolled. Clinical features and tidal changes in esophageal and nasal pressure were recorded on admission and 24 h after starting NRS. Correlation between ΔPes and ΔPnos served as primary outcome. The effect of ΔPnos measurements on respiratory rate and ΔPes was also assessed. RESULTS: ΔPes and ΔPnos were strongly correlated at admission (R2 = 0.88, p < 0.001) and 24 h apart (R2 = 0.94, p < 0.001). The nasal plug insertion and the mouth closure required for ΔPnos measurement did not result in significant change of respiratory rate and ΔPes. The correlation between measures at 24 h remained significant even after splitting the study population according to the type of NRS (high-flow nasal cannulas [R2 = 0.79, p < 0.001] or non-invasive ventilation [R2 = 0.95, p < 0.001]). CONCLUSIONS: In a cohort of patients with ARF, nasal pressure swings did not alter respiratory mechanics in the short term and were highly correlated with esophageal pressure swings during spontaneous tidal breathing. ΔPnos might warrant further investigation as a measure of inspiratory effort in patients with ARF. TRIAL REGISTRATION: NCT03826797 . Registered October 2016.

Molecular Mechanisms and Physiological Changes behind Benign Tracheal and Subglottic Stenosis in Adults.

Laryngotracheal stenosis (LTS) is a complex and heterogeneous disease whose pathogenesis remains unclear. LTS is considered to be the result of aberrant wound-healing process that leads to fibrotic scarring, originating from different aetiology. Although iatrogenic aetiology is the main cause of subglottic or tracheal stenosis, also autoimmune and infectious diseases may be involved in causing LTS. Furthermore, fibrotic obstruction in the anatomic region under the glottis can also be diagnosed without apparent aetiology after a comprehensive workup; in this case, the pathological process is called idiopathic subglottic stenosis (iSGS). So far, the laryngotracheal scar resulting from airway injury due to different diseases was considered as inert tissue requiring surgical removal to restore airway patency. However, this assumption has recently been revised by regarding the tracheal scarring process as a fibroinflammatory event due to immunological alteration, similar to other fibrotic diseases. Recent acquisitions suggest that different factors, such as growth factors, cytokines, altered fibroblast function and genetic susceptibility, can all interact in a complex way leading to aberrant and fibrotic wound healing after an insult that acts as a trigger. However, also physiological derangement due to LTS could play a role in promoting dysregulated response to laryngo-tracheal mucosal injury, through biomechanical stress and mechanotransduction activation. The aim of this narrative review is to present the state-of-the-art knowledge regarding molecular mechanisms, as well as mechanical and physio-pathological features behind LTS.

Endobronchial valve positioning for alveolar-pleural fistula following ICU management complicating COVID-19 pneumonia.

BACKGROUND: The main clinical consequences of severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) infection are pneumonia and respiratory failure even requiring mechanical ventilation. In this context, the lung parenchyma is highly prone to ventilator-related injury, with pneumothorax and persistent air leak as the most serious adverse events. So far, endobronchial valve (EBV) positioning has proved efficacious in treating air leaks with a high success rate. CASE PRESENTATION: We report, for the first time, two cases of patients affected by SARS-CoV-2-related pneumonia complicated with bacterial super-infection, experiencing pneumothorax and persistent air leaks after invasive mechanical ventilation. Despite the severity of respiratory failure both patients underwent rigid interventional bronchoscopy and were successfully treated through EBV positioning. CONCLUSIONS: Persistent air leaks may result from lung tissue damage due to a complex interaction between inflammation and ventilator-related injury (VILI), especially in the advanced stages of ARDS. EBV positioning seems to be a feasible and effective minimally invasive therapeutic option for treating this subset of patients.

Fibrotic Idiopathic Interstitial Lung Disease: The Molecular and Cellular Key Players.

Interstitial lung diseases (ILDs) that are known as diffuse parenchymal lung diseases (DPLDs) lead to the damage of alveolar epithelium and lung parenchyma, culminating in inflammation and widespread fibrosis. ILDs that account for more than 200 different pathologies can be divided into two groups: ILDs that have a known cause and those where the cause is unknown, classified as idiopathic interstitial pneumonia (IIP). IIPs include idiopathic pulmonary fibrosis (IPF), non-specific interstitial pneumonia (NSIP), cryptogenic organizing pneumonia (COP) known also as bronchiolitis obliterans organizing pneumonia (BOOP), acute interstitial pneumonia (AIP), desquamative interstitial pneumonia (DIP), respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), and lymphocytic interstitial pneumonia (LIP). In this review, our aim is to describe the pathogenic mechanisms that lead to the onset and progression of the different IIPs, starting from IPF as the most studied, in order to find both the common and standalone molecular and cellular key players among them. Finally, a deeper molecular and cellular characterization of different interstitial lung diseases without a known cause would contribute to giving a more accurate diagnosis to the patients, which would translate to a more effective treatment decision.

Pulmonary Stretch and Lung Mechanotransduction: Implications for Progression in the Fibrotic Lung.

Lung fibrosis results from the synergic interplay between regenerative deficits of the alveolar epithelium and dysregulated mechanisms of repair in response to alveolar and vascular damage, which is followed by progressive fibroblast and myofibroblast proliferation and excessive deposition of the extracellular matrix. The increased parenchymal stiffness of fibrotic lungs significantly affects respiratory mechanics, making the lung more fragile and prone to non-physiological stress during spontaneous breathing and mechanical ventilation. Given their parenchymal inhomogeneity, fibrotic lungs may display an anisotropic response to mechanical stresses with different regional deformations (micro-strain). This behavior is not described by the standard stress-strain curve but follows the mechano-elastic models of "squishy balls", where the elastic limit can be reached due to the excessive deformation of parenchymal areas with normal elasticity that are surrounded by inelastic fibrous tissue or collapsed induration areas, which tend to protrude outside the fibrous ring. Increasing evidence has shown that non-physiological mechanical forces applied to fibrotic lungs with associated abnormal mechanotransduction could favor the progression of pulmonary fibrosis. With this review, we aim to summarize the state of the art on the relation between mechanical forces acting on the lung and biological response in pulmonary fibrosis, with a focus on the progression of damage in the fibrotic lung during spontaneous breathing and assisted ventilatory support.

Molecular Mechanisms and Cellular Contribution from Lung Fibrosis to Lung Cancer Development.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrosing interstitial lung disease (ILD) of unknown aetiology, with a median survival of 2-4 years from the time of diagnosis. Although IPF has unknown aetiology by definition, there have been identified several risks factors increasing the probability of the onset and progression of the disease in IPF patients such as cigarette smoking and environmental risk factors associated with domestic and occupational exposure. Among them, cigarette smoking together with concomitant emphysema might predispose IPF patients to lung cancer (LC), mostly to non-small cell lung cancer (NSCLC), increasing the risk of lung cancer development. To this purpose, IPF and LC share several cellular and molecular processes driving the progression of both pathologies such as fibroblast transition proliferation and activation, endoplasmic reticulum stress, oxidative stress, and many genetic and epigenetic markers that predispose IPF patients to LC development. Nintedanib, a tyrosine-kinase inhibitor, was firstly developed as an anticancer drug and then recognized as an anti-fibrotic agent based on the common target molecular pathway. In this review our aim is to describe the updated studies on common cellular and molecular mechanisms between IPF and lung cancer, knowledge of which might help to find novel therapeutic targets for this disease combination.

When sarcoidosis hits down: a case of prostatic sarcoidosis.

A 69-year-old North African male with established diagnosis of sarcoidosis underwent a stereotactic prostate biopsy with fusion technique. At the histological analysis, non-necrotizing micro-granulomas were highlighted in 2 samples, while the immunohistochemical staining resulted negative for CK903/p63/racemase. To the best of our knowledge, only 16 cases of prostatic sarcoidosis have been reported in literature. With this case report we describe an incidental diagnosis of prostatic involvement of sarcoidotic disease and briefly review and discuss the available literature on the topic.

Expression of HOXB7 in the Lung of Patients with Idiopathic Pulmonary Fibrosis: A Proof-of-Concept Study.

BACKGROUND: The molecular pathways involved in the onset and progression of idiopathic pulmonary fibrosis (IPF) still need to be fully clarified as some are shared with lung cancer development. HOXB7, a member of the homeobox (Hox) gene family, has been found involved in various cancers. METHODS: Immunohistochemical (IHC) analysis was run on lung tissue samples from surgical lung biopsy (SLB) of 19 patients with IPF, retrospectively selected from the IPF database of the University Hospital of Modena. HOXB7 expression was analyzed and compared with that of five patients with no evidence of pulmonary fibrosis as controls. RESULTS: The semi-quantitative analysis of IHC showed that HOXB7 protein expression was higher in IPF patients compared to controls (difference between means = 6.2 ± 2.37, p = 0.0157). Further, HOXB7 expression was higher in IPF patients with a higher extent of fibrosis (50-75%)-measured with high-resolution computer tomography-compared to those with a lower extent (0-25%) (difference between means = 25.74 ± 6.72, p = 0.004). CONCLUSIONS: The expression of HOXB7 is higher in the lung of IPF patients compared to controls, and was represented in different cellular compartments within the lung niche. Further investigations are needed to clarify its role in the pathogenesis and progression of IPF.

Integrated endoscopic treatment of primitive unresectable tracheal tumor: the INTACT retrospective cohort study.

Background: Primitive tracheal tumors represent a rare entity whose management, when unresectable, remains challenging. Primary aim of this study was to explore the survival and the factors influencing prognosis of patients with unresectable primitive tracheal tumor undergoing multimodal treatment integrating interventional bronchoscopy and radiotherapy. Methods: This retrospective cohort study was conducted at the University Hospital of Modena (Italy) over a 12-year period (January 2010 to January 2022) analyzing patients with unresectable primary tracheal tumor receiving interventional bronchoscopy treatment followed by radiotherapy. Survival analysis was conducted for the whole population and according to histology, development of metastasis, stent placement and the onset of disease relapse. The raw and independent association between potential risk factor and 5-year mortality and the reported complications were investigated. Results: A total of 12 patients were included. Five-year survival rate was 42% with a median survival time of 26.7 (interquartile range, 4.1-82) months. Survivors showed a higher prevalence of cystic-adenoid histology (80% vs. 14%), while patients who were dead at 5 years were those with a more advanced T (prevalence of T2: 71% vs. 0%) and a lower response to first line treatment (57% vs. 0%). Treatment complications accounted for stent dislocation (33%) and the onset of granuloma (18%), while no major side effects were reported. The presence of cystic-adenoid histology resulted in significantly improved 5-year survival rate (80% vs. 14%). The onset of distal metastasis, the occurrence of disease relapse and the placement of tracheal stent did not result significantly associated with lower survival. Among analysed variables, only the presence of cystic-adenoid histology resulted independently associated with survival (odds ratio =0.1, P=0.04). Conclusions: Multimodal treatment including interventional bronchoscopy and associated radiotherapy for unresectable primary tracheal tumors seems not burdened by significant complications and may provide benefits in terms of survival for those patients with cystic-adenoid histology.

Effect of high flow nasal oxygen on inspiratory effort of patients with acute hypoxic respiratory failure and do not intubate orders.

High flow nasal oxygen (HFNO) is recommended as a first-line respiratory support during acute hypoxic respiratory failure (AHRF) and represents a proportionate treatment option for patients with do not intubate (DNI) orders. The aim of the study is to assess the effect of HFNO on inspiratory effort as assessed by esophageal manometry in a population of DNI patients suffering from AHRF. Patients with AHRF and DNI orders admitted to Respiratory intermediate Care Unit between January 1st, 2018 and May 31st, 2023 to receive HFNO and subjected to esophageal manometry were enrolled. Esophageal pressure swing (ΔPes), clinical variables before and after 2 h of HFNO and clinical outcome (including HFNO failure) were collected and compared as appropriate. The change in physiological and clinical parameters according to the intensity of baseline breathing effort was assessed and the correlation between baseline ΔPes values and the relative change in breathing effort and clinical variables after 2 h of HFNO was explored. Eighty-two consecutive patients were enrolled according to sample size calculation. Two hours after HFNO start, patients presented significant improvement in ΔPes (12 VS 16 cmH2O, p < 0.0001), respiratory rate (RR) (22 VS 28 bpm, p < 0.0001), PaO2/FiO2 (133 VS 126 mmHg, p < 0.0001), Heart rate, Acidosis, Consciousness, Oxygenation and respiratory rate (HACOR) score, (4 VS 6, p < 0.0001), Respiratory rate Oxygenation (ROX) index (8.5 VS 6.1, p < 0.0001) and BORG (1 VS 4, p < 000.1). Patients with baseline ΔPes below 20 cmH2O where those who improved all the explored variables, while patients with baseline ΔPes above 30 cmH2O did not report significant changes in physiological or clinical features. A significant correlation was found between baseline ΔPes values and after 2 h of HFNO (R2 = 0.9, p < 0.0001). ΔPes change 2 h after HFNO significantly correlated with change in BORG (p < 0.0001), ROX index (p < 0.0001), HACOR score (p < 0.001) and RR (p < 0.001). In DNI patients with AHRF, HFNO was effective in reducing breathing effort and improving respiratory and clinical variables only for those patients with not excessive inspiratory effort.

Stress-strain curve and elastic behavior of the fibrotic lung with usual interstitial pneumonia pattern during protective mechanical ventilation.

Patients with acute exacerbation of lung fibrosis with usual interstitial pneumonia (EUIP) pattern are at increased risk for ventilator-induced lung injury (VILI) and mortality when exposed to mechanical ventilation (MV). Yet, lack of a mechanical model describing UIP-lung deformation during MV represents a research gap. Aim of this study was to develop a constitutive mathematical model for UIP-lung deformation during lung protective MV based on the stress-strain behavior and the specific elastance of patients with EUIP as compared to that of acute respiratory distress syndrome (ARDS) and healthy lung. Partitioned lung and chest wall mechanics were assessed for patients with EUIP and primary ARDS (1:1 matched based on body mass index and PaO2/FiO2 ratio) during a PEEP trial performed within 24 h from intubation. Patient's stress-strain curve and the lung specific elastance were computed and compared with those of healthy lungs, derived from literature. Respiratory mechanics were used to fit a novel mathematical model of the lung describing mechanical-inflation-induced lung parenchyma deformation, differentiating the contributions of elastin and collagen, the main components of lung extracellular matrix. Five patients with EUIP and 5 matched with primary ARDS were included and analyzed. Global strain was not different at low PEEP between the groups. Overall specific elastance was significantly higher in EUIP as compared to ARDS (28.9 [22.8-33.2] cmH2O versus 11.4 [10.3-14.6] cmH2O, respectively). Compared to ARDS and healthy lung, the stress/strain curve of EUIP showed a steeper increase, crossing the VILI threshold stress risk for strain values greater than 0.55. The contribution of elastin was prevalent at lower strains, while the contribution of collagen was prevalent at large strains. The stress/strain curve for collagen showed an upward shift passing from ARDS and healthy lungs to EUIP lungs. During MV, patients with EUIP showed different respiratory mechanics, stress-strain curve and specific elastance as compared to ARDS patients and healthy subjects and may experience VILI even when protective MV is applied. According to our mathematical model of lung deformation during mechanical inflation, the elastic response of UIP-lung is peculiar and different from ARDS. Our data suggest that patients with EUIP experience VILI with ventilatory setting that are lung-protective for patients with ARDS.

Proteomic profiling of formalin-fixed paraffine-embedded tissue reveals key proteins related to lung dysfunction in idiopathic pulmonary fibrosis.

Introduction: Idiopathic pulmonary fibrosis (IPF) severely affects the lung leading to aberrant deposition of extracellular matrix and parenchymal stiffness with progressive functional derangement. The limited availability of fresh tissues represents one of the major limitations to study the molecular profiling of IPF lung tissue. The primary aim of this study was to explore the proteomic profiling yield of archived formalin-fixed paraffin-embedded (FFPE) specimens of IPF lung tissues. Methods: We further determined the protein expression according to respiratory functional decline at the time of biopsy. The total proteins isolated from 11 FFPE samples of IPF patients compared to 3 FFPE samples from a non-fibrotic lung defined as controls, were subjected to label-free quantitative proteomic analysis by liquid chromatography-mass spectrometry (LC-MS/MS) and resulted in the detection of about 400 proteins. Results: After the pairwise comparison between controls and IPF, functional enrichment analysis identified differentially expressed proteins that were involved in extracellular matrix signaling pathways, focal adhesion and transforming growth factor ß (TGF-ß) signaling pathways strongly associated with IPF onset and progression. Five proteins were significantly over- expressed in the lung of IPF patients with either advanced disease stage (Stage II) or impaired pulmonary function (FVC<75, DLCO<55) compared to controls; these were lymphocyte cytosolic protein 1 (LCP1), peroxiredoxin-2 (PRDX2), transgelin 2 (TAGLN2), lumican (LUM) and mimecan (OGN) that might play a key role in the fibrogenic processes. Discussion: Our work showed that the analysis of FFPE samples was able to identify key proteins that might be crucial for the IPF pathogenesis. These proteins are correlated with lung carcinogenesis or involved in the immune landscape of lung cancer, thus making possible common mechanisms between lung carcinogenesis and fibrosis progression, two pathological conditions at risk for each other in the real life.

Risk Factors for Pulmonary Air Leak and Clinical Prognosis in Patients With COVID-19 Related Acute Respiratory Failure: A Retrospective Matched Control Study.

Background: The role of excessive inspiratory effort in promoting alveolar and pleural rupture resulting in air leak (AL) in patients with SARS-CoV-2 induced acute respiratory failure (ARF) while on spontaneous breathing is undetermined. Methods: Among all patients with COVID-19 related ARF admitted to a respiratory intensive care unit (RICU) and receiving non-invasive respiratory support, those developing an AL were and matched 1:1 [by means of PaO2/FiO2 ratio, age, body mass index-BMI and subsequent organ failure assessment (SOFA)] with a comparable population who did not (NAL group). Esophageal pressure (ΔPes) and dynamic transpulmonary pressure (ΔPL) swings were compared between groups. Risk factors affecting AL onset were evaluated. The composite outcome of ventilator-free-days (VFD) at day 28 (including ETI, mortality, tracheostomy) was compared between groups. Results: Air leak and NAL groups (n = 28) showed similar ΔPes, whereas AL had higher ΔPL (20 [16-21] and 17 [11-20], p = 0.01, respectively). Higher ΔPL (OR = 1.5 95%CI[1-1.8], p = 0.01), positive end-expiratory pressure (OR = 2.4 95%CI[1.2-5.9], p = 0.04) and pressure support (OR = 1.8 95%CI[1.1-3.5], p = 0.03), D-dimer on admission (OR = 2.1 95%CI[1.3-9.8], p = 0.03), and features suggestive of consolidation on computed tomography scan (OR = 3.8 95%CI[1.1-15], p = 0.04) were all significantly associated with AL. A lower VFD score resulted in a higher risk (HR = 3.7 95%CI [1.2-11.3], p = 0.01) in the AL group compared with NAL. RICU stay and 90-day mortality were also higher in the AL group compared with NAL. Conclusion: In spontaneously breathing patients with COVID-19 related ARF, higher levels of ΔPL, blood D-dimer, NIV delivery pressures and a consolidative lung pattern were associated with AL onset.

Stenting versus balloon dilatation in patients with tracheal benign stenosis: The STROBE trial.

Background: It is well known that benign tracheal stenosis represents an obstacle to open surgery, and that its treatment could be challenging. Two endoscopic techniques have so far been adopted to restore tracheal patency: balloon dilatation (BA) through laryngoscopy, and tracheal stenting (ST) with rigid bronchoscopy. The main objective of this study was to compare the efficacy of BA and ST to treat benign tracheal stenosis not eligible for surgery. We also compared the rate of adverse events in the two treatment groups. Methods: A retrospective, observational cohort study was carried out at the University Hospital of Modena (Italy) from November 2012 to November 2017 in two separate departments. Patients were considered to be "stabilized" (primary outcome) if they did not report significant respiratory symptoms, or restenosis in the long-term (2 years) following the endoscopic procedure. Results: Sixty-six patients were included in the study (33 in the BA and 33 in the ST group, respectively). Unadjusted Kaplan-Meier estimates showed a greater therapeutic effect of ST compared to BA at 2 years (hazard ratio = 3.9 95%CI [1.5-9.8], p = .01). After adjusting for confounders, stratified analyses showed that this effect was significant in patients with complex stenosis, idiopathic etiology, and degree of stenosis >70%. Compared with BA, ST showed a higher rate of adverse events (p = .01). Conclusions: Compared to BA, ST seems to be more effective in achieving stabilization of tracheal patency in complex benign tracheal stenosis, although burdened with a significantly higher number of adverse effects. These findings warrant future prospective study for confirmation. Level of evidence: 3.

Delirium incidence and risk factors in patients undergoing non-invasive ventilation for acute respiratory failure: a multicenter observational trial.

BACKGROUND: Noninvasive ventilation (NIV) still has high failure rate when used for de novo acute respiratory failure (ARF). Delirium may impact the outcome, however data regarding its incidence, timing of occurrence and clinical predictors in this subset of patients are scarce. METHODS: Consecutive patients with de novo ARF subjected to NIV were recruited in 10 Italian Respiratory Intensive Care Units (RICUs) and Intensive Care Units (ICUs). Demographics and clinical features, including tolerance to interface and NIV setting were recorded on admission and during stay, whereas delirium onset and type was assessed by the Confusion Assessment Method for ICU (CAM-ICU)-7 scale and Richmond Agitation Sedation Scale (RASS) twice/per day up to a week. The association between clinical variables and the occurrence of delirium and its influence on NIV failure and other clinical outcomes were analyzed. RESULTS: Thirty-two out of 90 enrolled patients (36%) developed delirium over seven days upon admission; median time to onset was 48 hours (24-60). Older age (OR=2.7 [1.9-9], P=0.01), the presence of cancer OR=3.7 [2-5.4], P=0.002), sepsis (OR=1.7 [1.1-3.4], P=0.01), SOFA Score (OR=1.8 [1.1-3.1], P=0.01), low tolerance to interface (OR=3.2 [2.1-5], P=0.002), use of helmet (OR=1.9 [1.2-4.3] P=0.04), and higher PRE-DELIRIC (OR=3.5 [1.3-15], P=0.03) and BORG (OR=1.7 [1.1-4.6], P=0.02] scores were significantly associated with delirium. Delirium had high risk for NIV failure (HR=3.5 95% CI: [1.4-8.6], P=0.0002) and it significantly associated with longer RICU/ICU stay and higher mortality. CONCLUSIONS: Delirium onset in acute hypoxic patients undergoing NIV is frequent and negatively affects the outcome. Multiple related clinical factors should be addressed early on admission to prevent the delirium-related risk of NIV failure in these patients.

Early awake proning in critical and severe COVID-19 patients undergoing noninvasive respiratory support: A retrospective multicenter cohort study.

BACKGROUND/MATERIALS AND METHODS: This retrospective cohort study was conducted in two teaching hospitals over a 3-month period (March 2010-June 2020) comparing severe and critical COVID-19 patients admitted to Respiratory Intensive Care Unit for non-invasive respiratory support (NRS) and subjected to awake prone position (PP) with those receiving standard care (SC). Primary outcome was endotracheal intubation (ETI) rate. In-hospital mortality, time to ETI, tracheostomy, length of RICU and hospital stay served as secondary outcomes. Risk factors associated to ETI among PP patients were also investigated. RESULTS: A total of 114 patients were included, 76 in the SC and 38 in the PP group. Unadjusted Kaplan-Meier estimates showed greater effect of PP compared to SC on ETI rate (HR = 0.45 95% CI [0.2-0.9], p = 0.02) even after adjustment for baseline confounders (HR = 0.59 95% CI [0.3-0.94], p = 0.03). After stratification according to non-invasive respiratory support, PP showed greater significant benefit for those on High Flow Nasal Cannulae (HR = 0.34 95% CI [0.12-0.84], p = 0.04). Compared to SC, PP patients also showed a favorable difference in terms of days free from respiratory support, length of RICU and hospital stay while mortality and tracheostomy rate were not significantly different. CONCLUSIONS: Prone positioning in awake and spontaneously breathing Covid-19 patients is feasible and associated with a reduction of intubation rate, especially in those patients undergoing HFNC. Although our results are intriguing, further randomized controlled trials are needed to answer all the open questions remaining pending about the real efficacy of PP in this setting.