45 research outputs found
Acute exacerbation of idiopathic pulmonary fibrosis: Lessons learned from acute respiratory distress syndrome?
Idiopathic pulmonary fibrosis (IPF) is a fibrotic lung disease characterized by progressive loss of lung function and poor prognosis. The so-called acute exacerbation of IPF (AE-IPF) may lead to severe hypoxemia requiring mechanical ventilation in the intensive care unit (ICU). AE-IPF shares several pathophysiological features with acute respiratory distress syndrome (ARDS), a very severe condition commonly treated in this setting. A review of the literature has been conducted to underline similarities and differences in the management of patients with AE-IPF and ARDS. During AE-IPF, diffuse alveolar damage and massive loss of aeration occurs, similar to what is observed in patients with ARDS. Differently from ARDS, no studies have yet concluded on the optimal ventilatory strategy and management in AE-IPF patients admitted to the ICU. Notwithstanding, a protective ventilation strategy with low tidal volume and low driving pressure could be recommended similarly to ARDS. The beneficial effect of high levels of positive end-expiratory pressure and prone positioning has still to be elucidated in AE-IPF patients, as well as the precise role of other types of respiratory assistance (e.g., extracorporeal membrane oxygenation) or innovative therapies (e.g., polymyxin-B direct hemoperfusion). The use of systemic drugs such as steroids or immunosuppressive agents in AE-IPF is controversial and potentially associated with an increased risk of serious adverse reactions. Common pathophysiological abnormalities and similar clinical needs suggest translating to AE-IPF the lessons learned from the management of ARDS patients. Studies focused on specific therapeutic strategies during AE-IPF are warranted
Respiratory mechanics and diaphragmatic dysfunction in COPD patients who failed non-invasive mechanical ventilation
Background. Although non-invasive mechanical ventilation (NIV) is the gold standard treatment for patients with acute exacerbation of COPD (AECOPD) developing respiratory acidosis, failure rates still range from 5% to 40%. Recent studies have shown that the onset of severe diaphragmatic dysfunction (DD) during AECOPD increases risk of NIV failure and mortality in this subset of patients. Although the imbalance between the load and the contractile capacity of inspiratory muscles seems the main cause of AECOPD-induced hypercapnic respiratory failure, data regarding the influence of mechanical derangement on DD in this acute phase are lacking. With this study we investigate the impact of respiratory mechanics on diaphragm function in AECOPD patients experiencing NIV failure. Methods. Twelve AECOPD with respiratory acidosis admitted to the Respiratory ICU of the University Hospital of Modena from 2017-2018 undergoing mechanical ventilation (MV) due to NIV failure were enrolled. Static respiratory mechanics and end expiratory lung volume (EELV) were measured after 30 minutes of volume control mode MV. Subsequently transdiaphragmatic pressure (Pdi) was calculated by means of a sniff maneuver (Pdisniff) after 30 minutes of spontaneous breathing trial. Linear regression analysis and Pearsonâs correlation coefficient served to assess associations. Results. Average Pdisniff was 23.3 (standard deviation, SD=29) cmH20 with 3 patients presenting bilateral diaphragm palsy. Pdisniff was directly correlated with static lung elastance (r=0.69, p=0.001) while inverse correlation was found with dynamic intrinsic PEEP (r=-0.73, p=0.007). No significant correlation was found with static intrinsic PEEP (r=-0.55, p=0.06), EELV (r=-0.4, p=0.3), airway resistance (r=-0.2, p=0.54), chest wall and total elastance (r=-0-01, p=0.96 and r=0.3, p=0.36 respectively). Significant linear inverse correlation was found between Pdi/Pdisniff and Pdisniff (r=-0.82, p=0.02). Conclusion. The causes of extreme DD in AECOPD patients who experienced NIV failure might be predominantly mechanical, driven by a severe dynamic hyperinflation that overlaps on an elastic lung substrate favoring volume overload
Prevalence and development of chronic critical illness in acute patients admitted to a respiratory intensive care setting
Introduction- Chronic Critical Illness (chronic CI) is a condition associated to patients surviving an episode of acute respiratory failure (ARF). The prevalence and the factors associated with the development of chronic CI in the population admitted to a Respiratory Intensive Care Unit (RICU) have not been yet elucidated. Methods- An observational prospective cohort study was undertaken at the RICU of the University Hospital of Modena (Italy). Patients mechanically ventilated with ARF in RICU were enrolled. Demographics, severity scores (APACHEII, SOFA, SAPSII), and clinical condition (septic shock, pneumonia, ARDS) were recorded on admission. Respiratory mechanics and inflammatory-metabolic blood parameters were measured both on admission and over the first week of stay. All variables were tested as predictors of chronic CI through univariate and multivariate analysis. Results- chronic CI occurred in 33 out of 100 patients observed. Higher APACHEII, the presence of septic shock, diaphragmatic dysfunction (DD) at sonography, multidrug-resistant (MDR) bacterial infection, the occurrence of a second infection during stay, and a C-reactive protein (CRP) serum level inceasing 7 days over admission were associated with chronic CI. Septic shock was the strongest predictor of chronic CI (AUC=0.92 p<0.0001). Conclusions- Chronic CI is frequent in patients admitted to RICU and mechanically ventilated due to ARF. Infection-related factors seem to play a major role as predictors of this syndrome
Early inspiratory effort assessment by esophageal manometry early predicts noninvasive ventilation outcome in de novo respiratory failure: a pilot study.
Rationale: The role of inspiratory effort has still to be determined as a potential predictors of non-invasive mechanical ventilation (NIV) failure in acute hypoxic de novo respiratory failure (AHRF). Objectives: We explore the hypothesis that inspiratory effort might be a major determinant of NIV failure in these patients. Methods: Thirty consecutive patients with AHRF admitted to a single center and candidates for a 24-hour NIV trial were enrolled. Clinical features, tidal changes in esophageal (ÎPes) and dynamic transpulmonary pressure (ÎPL), expiratory tidal volume, and respiratory rate were recorded on admission and 2-4-12-24 hours after NIV start, and were tested for correlation with outcomes. Measurements and Main Results: ÎPes and ÎPes/ÎPL were significantly lower 2 hours after NIV start in patients who successfully completed the NIV trial (n=18) compared to those who needed endotracheal intubation (n=12) [median=11 (IQR=8â15) cmH2O vs 31.5 (30â36) cmH2O, p<0.0001] while other variables differed later. ÎPes was not related to other predictors of NIV failure at baseline. NIV-induced reduction in ÎPes of 10 cmH2O or more after 2 hours of treatment was strongly associated to avoidance of intubation, and represented the most accurate predictor of treatment success (OR=15, 95%CI 2.8-110, p=0.001, AUC=0.97, 95%CI 0.91â1, p<0.0001). Conclusions: The magnitude of inspiratory effort relief as assessed by ÎPes variation within the first 2 hours of NIV was an early and accurate predictor of NIV outcome at 24 hours
Serial Ultrasound Assessment of Diaphragmatic Function and Clinical Outcome in Patients with Amyotrophic Lateral Sclerosis.
Background: Ultrasound (US) evaluation of the diaphragm may be a non-volitional useful tool in the clinical management of patients with ALS. Aim of the present study was then to evaluate the impact of serial assessment of ÎTmax index on clinical outcomes during the follow-up in these patients and to correlate non-volitional US indices and other volitional measures with these outcomes.
Methods: A cohort of 39 consecutive patients with ALS was followed up to 24 months. At baseline and every 3-month spirometry (forced vital capacity-FVC), sniff inspiratory nasal pressure (SNIP), and US of the diaphragm (ÎTdi and ÎTmax) were recorded. These parameters were correlated with clinical outcomes (hypercapnia, nocturnal hypoventilation, NIV start in the following 6 month, and death within 1 year).
Results: The occurrence of ÎTmax >0.75 during follow-up increased the risk for NIV (HR=5.6, p=0.001) and death (HR=3.7, p=0.0001) compared with patients with stable lower values. The evidence of diaphragmatic dysfunction, i.e. ÎTmax >0.75, occurs 3.2 month earlier than the onset of NIV. Moreover, ÎTmax >0.75 correlated with onset of nocturnal hypoventilation, NIV initiation within 6 months, and death within 12 months, similarly to FVC <50% predicted and better than other functional indices.
Conclusions: Serial monitoring of diaphragmatic ÎTmax by US may be useful to predict initiation of NIV and death in patients with ALS. The occurrence of an abnormal ÎTmax value in the follow-up precedes the decision for starting NIV
Ventilatory support and mechanical properties of the fibrotic lung acting as a "squishy ball"
Protective ventilation is the cornerstone of treatment of patients with the acute respiratory distress syndrome (ARDS); however, no studies have yet established the best ventilatory strategy to adopt when patients with acute exacerbation of interstitial lung disease (AE-ILD) are admitted to the intensive care unit. Due to the severe impairment of the respiratory mechanics, the fibrotic lung is at high risk of developing ventilator-induced lung injury, regardless of the lung fibrosis etiology. The purpose of this review is to analyze the effects of mechanical ventilation in AE-ILD and to increase the knowledge on the characteristics of fibrotic lung during artificial ventilation, introducing the concept of "squishy ball lung". The role of positive end-expiratory pressure is discussed, proposing a "lung resting strategy" as opposed to the "open lung approach". The review also discusses the practical management of AE-ILD patients discussing illustrative clinical cases
Molecular mechanisms and cellular contribution from lung fibrosis to lung cancer development.
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrosing interstitial lung 28 disease (ILD) of unknown etiology, with a median survival of 2-4 years from the time of diagnosis. 29 Although IPF has unknown etiology by definition, there have been identified several risks factors 30 increasing the probability of the onset and progression of the disease in IPF patients such as cigarette 31 smoking and environmental risks factors associated to domestic and occupational exposure. Among 32 them, cigarette smoking together with concomitant emphysema might predispose IPF patients to 33 lung cancer (LC), mostly to non-small cell lung cancer (NSCLC), increasing the risk of lung cancer 34 development. To this purpose, IPF and LC share several cellular and molecular processes driving 35 the progression of both pathologies such as fibroblast transition proliferation and activation, endo- 36 plasmic reticulum stress, oxidative stress, and many genetic and epigenetic markers that predispose 37 the IPF patients to LC development. Nintedanib, a tyrosine-kinase inhibitor, was firstly developed 38 as an anticancer drug and then recognized as an anti-fibrotic agent based on the common target 39 molecular pathway. In this review our aim is to describe the updated studies on common cellular 40 and molecular mechanisms between IPF and lung cancer, whose knowledge might help to find 41 novel therapeutic targets for this disease combination
Stress-strain curve and elastic behavior of the fibrotic lung with usual interstitial pneumonia pattern during protective mechanical ventilation
Background- 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.
Methods- 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. Patientâs 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.
Results- 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 â 33.2] cmH2O versus 11.4 [10.3 â 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.
Conclusions- 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
Dissecting the Role of Mesenchymal Stem Cells in Idiopathic Pulmonary Fibrosis:Cause or Solution
Idiopathic pulmonary fibrosis (IPF) is one of the most aggressive forms of idiopathic interstitial pneumonias, characterized by chronic and progressive fibrosis subverting the lungâs architecture, pulmonary functional decline, progressive respiratory failure, and high mortality (median survival 3Â years after diagnosis). Among the mechanisms associated with disease onset and progression, it has been hypothesized that IPF lungs might be affected either by a regenerative deficit of the alveolar epithelium or by a dysregulation of repair mechanisms in response to alveolar and vascular damage. This latter might be related to the progressive dysfunction and exhaustion of the resident stem cells together with a process of cellular and tissue senescence. The role of endogenous mesenchymal stromal/stem cells (MSCs) resident in the lung in the homeostasis of these mechanisms is still a matter of debate. Although endogenous MSCs may play a critical role in lung repair, they are also involved in cellular senescence and tissue ageing processes with loss of lung regenerative potential. In addition, MSCs have immunomodulatory properties and can secrete anti-fibrotic factors. Thus, MSCs obtained from other sources administered systemically or directly into the lung have been investigated for lung epithelial repair and have been explored as a potential therapy for the treatment of lung diseases including IPF. Given these multiple potential roles of MSCs, this review aims both at elucidating the role of resident lung MSCs in IPF pathogenesis and the role of administered MSCs from other sources for potential IPF therapies
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 (ÎPes) and dynamic transpulmonary pressure (ÎPL) 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- AL and NAL groups (n=28) showed similar ÎPes, whereas AL had higher ÎPL (20 [16â21] and 17 [11â20], p=0.01 respectively). Higher ÎPL (OR=1.5 95%CI[1â1.8], p=0.01), positive endâexpiratory pressure (OR=2.4 95%CI[1.2â5.9], 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.
Conclusions- In spontaneously breathing patients with COVIDâ19 related ARF, higher levels of ÎPL, blood Dâdimer, NIV delivery pressures and a consolidative lung pattern were associated with AL onset