The Effect of Pressure Changes During Mechanical Insufflation-Exsufflation on Respiratory and Airway Physiology.

BACKGROUND: Respiratory muscle weakness can impair cough function, leading to lower respiratory tract infections. These infections are an important contributor to morbidity and mortality in patients with neuromuscular disease. Mechanical insufflation-exsufflation (MIE) is used to augment cough function in these patients. Although MIE is widely used, there are few data to advise on the optimal technique. Since the introduction of MIE, the recommended pressures to be delivered have increased. There are concerns regarding the use of higher pressures and their potential to cause lung derecruitment and upper airway closure. RESEARCH QUESTION: What is the impact of high-pressure MIE (HP-MIE) on lung recruitment, respiratory drive, upper airway flow, and patient comfort, compared with low-pressure MIE (LP-MIE), in patients with respiratory muscle weakness? STUDY DESIGN AND METHODS: Clinically stable patients using domiciliary MIE with respiratory muscle weakness secondary to Duchenne muscle dystrophy, spinal cord injury, or long-term tracheostomy ventilation received LP-MIE (30/-30 cm H2O) and HP-MIE (60/-60 cm H2O) in a random sequence. Lung recruitment, neural respiratory drive, and cough peak expiratory flow were measured throughout, and patients reported comfort and breathlessness following each intervention. RESULTS: A total of 29 patients (10 with Duchenne muscle dystrophy, eight with spinal cord injury, and 11 with long-term tracheostomy ventilation) were included in this study. HP-MIE augmented cough peak expiratory flow compared with LP-MIE (mean cough peak expiratory flow HP-MIE 228 ± 81 L/min vs LP-MIE 179 ± 67 L/min; P = .0001) without any significant change in lung recruitment, neural respiratory drive, or patient-reported breathlessness. However, in patients with more pronounced respiratory muscle weakness, HP-MIE resulted in an increased rate of upper airway closure and patient discomfort that may have an impact on clinical efficacy. INTERPRETATION: HP-MIE did not lead to lung derecruitment or breathlessness compared with LP-MIE. However, it was poorly tolerated in individuals with advanced respiratory muscle weakness. HP-MIE generates more upper airway closure than LP-MIE, which may be missed if cough peak expiratory flow is used as the sole titration target. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov; No.: NCT02753959; URL: www. CLINICALTRIALS: gov.

Respiratory muscle metabolic activity on PET/CT correlates with obstructive ventilatory defect severity and prognosis in patients undergoing lung cancer surgery.

BACKGROUND AND OBJECTIVE: Respiratory muscle activity is increased in patients with chronic respiratory disease. 18 F-FDG-PET/CT can assess respiratory muscle activity. We hypothesized that respiratory muscles metabolism was correlated to lung function impairment and was associated to prognosis in patients undergoing lung cancer surgery based on the research question whether respiratory muscle metabolism quantitatively correlates with the severity of lung function impairment in patients? Does respiratory muscle hypermetabolism have prognostic value? METHODS: Patients undergoing 18 F-FDG-PET/CT and pulmonary function tests prior to lung cancer surgery were identified. Maximum Standardized Uptake Value (SUVm) were measured in each respiratory muscle group (sternocleidomastoid, scalene, intercostal, diaphragm), normalized against deltoid SUVm. Respiratory muscle hypermetabolism was defined as SUVm >90th centile in any respiratory muscle group. Clinical outcomes were collected from a prospective cohort. RESULTS: One hundred fifty-six patients were included, mostly male [110 (71%)], 53 (34%) with previous diagnosis of COPD. Respiratory muscle SUVm were: scalene: 1.84 [1.51-2.25], sternocleidomastoid 1.64 [1.34-1.95], intercostal 1.01 [0.84-1.16], diaphragm 1.79 [1.41-2.27]. Tracer uptake was inversely correlated to FEV1 for the scalene (r = -0.29, p < 0.001) and SCM (r = -0.17, p = 0.03) respiratory muscle groups and positively correlated to TLC for the scalene (r = 0.17, p = 0.04). Respiratory muscle hypermetabolism was found in 45 patients (28.8%), who had a lower VO2 max (15.4 [14.2-17.5] vs. 17.2 mL/kg/min [15.2-21.1], p = 0.07) and poorer overall survival when adjusting to FEV1% (p < 0.01). CONCLUSION: Our findings show respiratory muscle hypermetabolism is associated with lung function impairment and has prognostic significance. 18 F-FDG/PET-CT should be considered as a tool for assessing respiratory muscle activity and to identify high-risk patients.

ERS International Congress 2020 Virtual: highlights from the Respiratory Intensive Care Assembly.

During the virtual European Respiratory Society Congress 2020, early career members summarised the sessions organised by the Respiratory Intensive Care Assembly. The topics covered included diagnostic strategies in patients admitted to the intensive care unit with acute respiratory failure, with a focus on patients with interstitial lung disease and for obvious reasons, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. These sessions are summarised in this article, with take-home messages highlighted.

Long-term survival following initiation of home non-invasive ventilation: a European study.

INTRODUCTION: Although home non-invasive ventilation (NIV) is increasingly used to manage patients with chronic ventilatory failure, there are limited data on the long-term outcome of these patients. Our aim was to report on home NIV populations and the long-term outcome from two European centres. METHODS: Cohort analysis including all patients established on home NIV from two European centres between 2008 and 2014. RESULTS: Home NIV was initiated in 1746 patients to treat chronic ventilatory failure caused by (1) obesity hypoventilation syndrome±obstructive sleep apnoea (OHS±OSA) (29.5%); (2) neuromuscular disease (NMD) (22.7%); and (3) obstructive airway diseases (OAD) (19.1%). Overall cohort median survival following NIV initiation was 6.6 years. Median survival varied by underlying aetiology of respiratory failure: rapidly progressive NMD 1.1 years, OAD 2.7 years, OHS±OSA >7 years and slowly progressive NMD >7 years. Multivariate analysis demonstrated higher mortality in patients with rapidly progressive NMD (HR 4.78, 95% CI 3.38 to 6.75), COPD (HR 2.25, 95% CI 1.64 to 3.10), age >60 years at initiation of home NIV (HR 2.41, 95% CI 1.92 to 3.02) and NIV initiation following an acute admission (HR 1.38, 95% CI 1.13 to 1.68). Factors associated with lower mortality were NIV adherence >4 hours per day (HR 0.64, 95% CI 0.51 to 0.79), OSA (HR 0.51, 95% CI 0.31 to 0.84) and female gender (HR 0.79, 95% CI 0.65 to 0.96). CONCLUSION: The mortality rate following initiation of home NIV is high but varies significantly according to underlying aetiology of respiratory failure. In patients with chronic respiratory failure, initiation of home NIV following an acute admission and low levels of NIV adherence are poor prognostic features and may be amenable to intervention.

Neural respiratory drive predicts long-term outcome following admission for exacerbation of COPD: a post hoc analysis.

Neural respiratory drive (NRD), as reflected by change in parasternal muscle electromyogram (EMGpara), predicts clinical deterioration and safe discharge in patients admitted to hospital with an acute exacerbation of COPD (AECOPD). The clinical utility of NRD to predict the long-term outcome of patients following hospital admission with an AECOPD is unknown. We undertook a post hoc analysis of a previously published prospective observational cohort study measuring NRD in 120 patients with AECOPD. Sixty-nine (57.5%) patients died during follow-up (median 3.6 years). Respiratory failure was the most common cause of death (n=29; 42%). In multivariate analysis, factors independently associated with an increased mortality included NRD (HR 2.14, 95% CI 1.29 to 3.54, p=0.003), age (HR 2.03, 95% CI 1.23 to 3.34, p=0.006), PaCO2 at admission (HR 1.83, 95% CI 1.06 to 3.06, p=0.022) and long-term oxygen use (HR 2.98, 95% CI 1.47 to 6.03, p=0.002). NRD at hospital discharge could be measured in order to assess efficacy of interventions targeted to optimise COPD and reduce mortality following an AECOPD. Original clinicaltrial.gov number: NCT01361451.

[Post-transplant pulmonary complications: Guidelines from the francophone Society of bone marrow transplantation and cellular therapy (SFGM-TC)]. / Complications pulmonaires post-greffe : recommandations de la Société francophone de greffe de moelle et de thérapie cellulaire (SFGM-TC).

Pulmonary complications after allogeneic hematopoietic stem cell transplantation occur frequently (30-75%), vary in severity, and sometimes prove lethal. They may occur at an early stage post-transplant before D100 but may also surface later. Etiological support for these complications has shown a beneficial impact on survival. When faced with early complications, non-invasive tests, scans, and microbiological tests must be rapidly implemented. In the majority of cases, these tests facilitate diagnosis. In cases where microbiological non-invasive tests are negative, and the patient shows a steady respiratory condition, bronchoalveolar lavage can be effective if it is implemented in the first four days following the onset of pulmonary symptoms. This diagnostic approach should in no way occlude the introduction of broad-spectrum antibiotics in these profoundly immunocompromised patients. Later pulmonary complications are the most often not infectious. They include different anatomo-clinical conditions: cryptogenic organizing pneumonia; interstitial lung disease; idiopathic pleuroparenchymal fibroelastosis. Vascular disorders may include hypertension, thrombotic microangiopathy, venous thromboembolism, and pleural effusions. These conditions must be monitored using RFE (respiratory functional exploration) which allows early detection and therapeutic intervention. A combination of RFE and thoracic radiology scans will provide diagnostic assessment. Bronchoalveolar lavage is indicated when an infection is suspected or before systemic corticosteroid therapy. A lung biopsy should be discussed on a case-by-case basis, such as in cases of interstitial pulmonary disorders.

Lung transplantation after allogeneic stem cell transplantation: a pan-European experience.

Late-onset noninfectious pulmonary complications (LONIPCs) affect 6% of allogeneic stem cell transplantation (SCT) recipients within 5 years, conferring subsequent 5-year survival of 50%. Lung transplantation is rarely performed in this setting due to concomitant extrapulmonary morbidity, excessive immunosuppression and concerns about recurring malignancy being considered contraindications. This study assesses survival in highly selected patients undergoing lung transplantation for LONIPCs after SCT.SCT patients undergoing lung transplantation at 20 European centres between 1996 and 2014 were included. Clinical data pre- and post-lung transplantation were reviewed. Propensity score-matched controls were generated from the Eurotransplant and Scandiatransplant registries. Kaplan-Meier survival analysis and Cox proportional hazard regression models evaluating predictors of graft loss were performed.Graft survival at 1, 3 and 5 years of 84%, 72% and 67%, respectively, among the 105 SCT patients proved comparable to controls (p=0.75). Sepsis accounted for 15 out of 37 deaths (41%), with prior mechanical ventilation (HR 6.9, 95% CI 1.0-46.7; p<0.001) the leading risk factor. No SCT-specific risk factors were identified. Recurring malignancy occurred in four patients (4%). Lung transplantation <2 years post-SCT increased all-cause 1-year mortality (HR 7.5, 95% CI 2.3-23.8; p=0.001).Lung transplantation outcomes following SCT were comparable to other end-stage diseases. Lung transplantation should be considered feasible in selected candidates. No SCT-specific factors influencing outcome were identified within this carefully selected patient cohort.

Neural respiratory drive and cardiac function in patients with obesity hypoventilation syndrome following initiation of non-invasive ventilation.

BACKGROUND: Chronic hypercapnic respiratory failure (HRF) in obesity hypoventilation syndrome (OHS) is commonly treated using non-invasive ventilation (NIV). We hypothesised that treatment of OHS would improve neural respiratory drive index (NRDI) and cardiac function. METHODS: Fourteen patients (8 females) with OHS, who were admitted for initiation of domiciliary NIV, were prospectively studied. Patients had (mean ± SD): age (53±10 years), body mass index (BMI) (50.1±10.8 kg/m2), and pCO2 (7.3±0.9 kPa). NRDI was assessed by surface electromyogram of the parasternal intercostals. Cardiac function was assessed by transthoracic echocardiography (TTE). All measurements were performed at baseline, 6 weeks, and 3 months. RESULTS: NRDI improved on day one following NIV set-up comparing to baseline (484.2±214.8 vs. 316.5±106.5 AU) and this improvement was maintained at 6 weeks (369.1±173.2 AU) and at 3 months (351.2±167.1 AU) (P=0.004). No significant differences were identified in terms of cardiac function between baseline and 3 months [tricuspid annular plane systolic excursion (TAPSE) (24.6±5.8 vs. 23.0±4.0 mm, P=0.317); systolic pulmonary artery (PA) pressures (36.7±15.2 vs. 44.5±23.9 mmHg, P=0.163]. CONCLUSIONS: NIV improves NRDI in patients with OHS, while the cardiac function over a three-month period remains unchanged.

Inhibition of T Cell Alloreactivity by Bronchial Epithelium Is Impaired in Lung Transplant Recipients, Through Pathways Involving TGF-ß, IL-10 and HLA-G.

BACKGROUND: Bronchiolitis obliterans syndrome (BOS) after lung transplantation (LTx) results from bronchial epithelial cell (BECs) damages, thought to be orchestrated by T cells primed by antigen-presenting cell presenting alloantigens. In this cell cross-talk, BECs are also suspected to play a pivotal immunosuppressive role in T cell alloreactivity. We studied the immunomodulating role of BECs in a human ex vivo model of allogeneic T cell response, both in healthy subjects and LTx recipients. METHODS: BECs from 35 LTx recipients (n = 22 stable, n = 13 BOS) and healthy controls (n = 25) were cultured as primary cell cultures. Their inhibitory capacities through the involvement of tolerogenic molecules (HLA-G, TGF-ß, and IL-10) were tested on a mixed lymphocyte reaction between antigen-presenting cells and recipient T cells. RESULTS: Control BECs inhibited T cell alloproliferation by a mean of 53 ± 7%. This inhibitory effect of BECs was significantly reduced in the stable LTx group (24 ± 8%, P = 0.009), but not in the BOS TxP group (53 ± 10%, P = 0.97). Neutralization of HLA-G, TGF-ß, and IL-10 partially restored T cell alloproliferation, arguing for their involvement in the immunosuppressive effect of BECs. BECs culture supernatant from stable LTx patients with impaired BEC properties showed a skewed Th2-type secretion profile (high IL-4/IFN-γ ratio). CONCLUSIONS: The inhibitory properties of BECs are dysregulated in stable LTx recipients, which could suggest their instrumental role in the initiation of BOS process and potential targeted therapies.

A Randomized Controlled Trial on the Effect of Needle Gauge on the Pain and Anxiety Experienced during Radial Arterial Puncture.

BACKGROUND: Arterial punctures for assessment of arterial blood-gases can be a painful procedure. Lidocaine can be used to reduce pain prior to needle insertion but it is not a widely accepted practice. The purpose of this study was to determine whether a large size needle induces more pain compared to a smaller size needle for radial arterial puncture and to assess the anxiety associated with radial arterial punctures. METHODS: We conducted a prospective, double-blind, randomized, controlled, monocentric study including all outpatients who had a planned assessment of arterial blood gas analysis. Patients were randomized to have the arterial puncture performed with a 23 or a 25 G needle. The main judgement criteria was pain during arterial puncture. Visual analogue scale for pain (VAS-P) and visual analogue scale for anxiety (VAS-A) were used to assess pain and anxiety during radial arterial puncture. RESULTS: Two hundred consecutive patients were randomized. The 25 G needle was as painful as the 23 G needle (6.63 mm [0-19 mm] vs. 5.21 mm [0-18.49 mm], respectively, p = 0.527). Time for arterial puncture was longer with the 25 G needle than with the 23 G needle (42 s [35-55 s] vs. 33 s [24.5-35 s], respectively, p = 0.002). There was a correlation between the level of anxiety prior to the arterial puncture and the pain experienced by the patients (p: 0.369, p<0.0001). There was a correlation between the pain experienced by patients and the anxiety experienced in anticipation of another arterial puncture (p: 0.5124, p<0.0001). CONCLUSIONS: The use of 23 G needle allows quicker arterial sampling and is not associated with increased pain and symptoms. Anxiety was correlated with the pain experienced by patients during arterial punctures. TRIAL REGISTRATION: Clinicaltrials.gov: NCT02320916.

Lung transplantation in patients with pretransplantation donor-specific antibodies detected by Luminex assay.

BACKGROUND: New methods of solid-phase assays, such as Luminex assay, with high sensitivity in detecting anti-human leukocyte antigen (HLA) antibodies (Abs), have increased the proportion of sensitized candidates waiting for lung transplantation (LTx). However, how to apply these results clinically during graft allocation is debated: strict exclusion of candidates with Luminex-positive results can lead to lost opportunities for Tx. We retrospectively analyzed the clinical impact of pre-LTx Luminex-detected Abs on post-LTx outcomes for patients who underwent LTx before the availability of Luminex assay. METHODS: We analyzed data for 56 successive patients who underwent LTx before 2008 and were considered to not have anti-HLA Abs by then-available methods of detection at the date of their LTx. Pre-LTx sera from these patients were retested by Luminex assay. Using log-rank test, freedom from bronchiolitis obliterans syndrome (BOS) and graft survival were compared between patients with and without pre-LTx Luminex-detected anti-HLA Abs classes I and II and donor-specific Abs (DSA) classes I and II. RESULTS: Freedom from bronchiolitis obliterans syndrome was lower, and mortality was higher for patients with than those without pre-LTx Luminex-detected DSA class II (P=0.004 and P=0.007, respectively) but did not differ for patients with and without DSA class I or anti-HLA Abs class I or II. CONCLUSIONS: It suggests to avoid attributing graft with forbidden antigens to sensitized candidates with Luminex-detected DSA class II and to evaluate the role of specific posttransplantation protocols for LTx candidates who require emergency LTx.

Relapsing Mycobacterium genavense infection as a cause of late death in a lung transplant recipient: case report and review of the literature.

Mycobacterium genavense is recognized as a life-threatening pathogen in severely immunocompromised patients, mostly in those with advanced human immunodeficiency virus infection. We report a case of M. genavense infection in a lung-transplant recipient with late-onset death occurring from disseminated infection. In human immunodeficiency virus-negative patients, there exist only about 10 reports of disseminated M. genavense infection in immunocompromised hosts; and to our knowledge, this is a first reported case of M. genavense infection after a lung transplant. Diagnosis of M. genavense was obtained only with nucleic acid-based identification technique, as frequently observed in a few cases of human immunodeficiency virus-negative patients. A striking feature was the recurrence of this infection in our patient after a seemingly infection-free period of 3 years. Because M. genavense infection can be life-threatening, clinicians must be aware of the frequent requirement for nucleic-acid-based identification for its diagnosis.