Predictors of survival in patients receiving domiciliary oxygen therapy or mechanical ventilation. A 10-year analysis of ANTADIR Observatory

Cohort study to evaluate prognostic factors in idiopathic pulmonary fibrosis patients introduced to oxygen therapy

While high-level evidence is lacking, numerous retrospective studies have depicted the value of supplemental oxygen in idiopathic pulmonary fibrosis (IPF) and other interstitial lung diseases, and its use should be encouraged where necessary. The clinical course and survival of patients with IPF who have been introduced to oxygen therapy is still not fully understood. The objective of this study was to clarify overall survival, factors associated with prognosis, and causes of death in IPF patients after the start of oxygen therapy. This is a prospective cohort multicenter study, enrolling patients with IPF who started oxygen therapy at 19 hospitals with expertise in interstitial lung disease. Baseline clinical data at the start of oxygen therapy and 3-year follow-up data including death and cause of death were assessed. Factors associated with prognosis were analyzed using univariable and multivariable analyses. One hundred forty-seven eligible patients, of whom 86 (59%) were prescribed ambulatory oxygen therapy and 61 (41%) were prescribed long-term oxygen therapy, were recruited. Of them, 111 died (76%) during a median follow-up of 479 days. The median survival from the start of oxygen therapy was 537 ± 74 days. In the univariable analysis, low body mass index (BMI), low forced vital capacity (FVC), low diffusion capacity (DLCO), resting hypoxemia, short 6 min-walk distance, and high COPD assessment test (CAT) score were significantly associated with poor prognosis. Multivariable analysis revealed low BMI, low FVC, low DLCO, low minimum SpO2 on 6MWT, and high CAT score were independent factors for poor prognosis. The overall survival of IPF patients after starting oxygen therapy is about 1.5 years. In addition to pulmonary function tests, 6MWT and patient reported outcomes can be used to predict prognosis more accurately.Clinical Trial Registration: UMIN000009322.

Mental health and quality of life among patients with chronic respiratory failure on domiciliary oxygen: a prospective cohort study from a tertiary care centre in India

OBJECTIVES

The study aims to assess the prevalence of anxiety, depression and the quality of life among patients with chronic respiratory failure and the changes in anxiety and depression scores after initiating domiciliary oxygen.

DESIGN AND SETTING

Prospective, single-centre cohort study conducted in a tertiary care hospital in India.

PARTICIPANTS

Patients of Indian origin with chronic respiratory failure who visited the hospital where domiciliary oxygen is indicated were included in the study. Patients with acute respiratory failure on a mechanical ventilator, haemodynamic instability and already-diagnosed psychiatric conditions were excluded from the study.

INTERVENTIONS

Patients who met the inclusion criteria were assessed at baseline, at 3 and 6 months, for anxiety and depression using the 7-item Generalised Anxiety Disorder questionnaire (GAD-7) and 9-item Patient Health Questionnaire (PHQ-9). Quality of life was evaluated using the WHO Quality of Life-BREF questionnaire.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome is the proportion of patients with chronic respiratory failure having depression and anxiety and assessing the changes in anxiety and depression scores after initiating domiciliary oxygen. The secondary outcome is the change in health-related quality of life (HRQOL) of patients on domiciliary oxygen.

RESULTS

121 patients who met the inclusion criteria were included in the study. Of 102 patients who completed the study, 36.2% (n=37) had anxiety and 44.1% (n=45) had depression at baseline. There is a worsening trend in the mean GAD-7 (p=0.003) and PHQ-9 score (p=0.015) in patients over 6 months while on domiciliary oxygen. HRQOL is poor in all the domains at baseline, and there is a progressive worsening during follow-up while on oxygen.

CONCLUSIONS

The worsening trend in anxiety and depression in patients after initiating domiciliary oxygen may be related to social isolation, restricted mobility, economic issues, addictions and frequency of exacerbations. Screening for psychological problems in these patients at baseline and on follow-ups helps early detection, and prompt intervention could improve the quality of life and survival.

Investigating the differences in nutritional status between successfully weaned and unsuccessfully weaned respirator patients

Long-term respirator users admitted to intensive care units need to be transferred to a respiratory care center (RCC) for weaning. It may cause malnutrition in critical care patients, which may manifest as a reduction in respiratory muscle mass, lower ventilatory capacity, and decreased respiratory tolerance. This study aimed to assess that if the patients' nutritional status were improved, it could help RCC patients to wean from respirators. All participants were recruited from the RCC of a medical foundation in the city and Taipei Tzu Chi Hospital. The indicators include serum albumin level, respirator detachment index, maximum inspiratory pressure (PImax), rapid shallow breathing index, and body composition measurements. We recorded the length of hospital stay, mortality, and RCW (respiratory care ward) referral rate for these participants and analyzed the differences in relevant research indicators between those who were and weren't weaned off. 43 of 62 patients were weaned from respirators, while 19 failed. The resuscitation rate was 54.8%. Patients with respirator weaning had a lower number of RCC admission days (23.1 ± 11.1 days) than respirator-dependent patients (35.6 ± 7.8 days, P < 0.05). The PImax of successfully weaned patients had a greater reduction (- 27.09 ± 9.7 cmH₂O) than unsuccessful ones (- 21.4 ± 10.2 cmH₂O, P < 0.05). The Acute Physiology and Chronic Health Evaluation II (APACHE II) scores of successfully weaned patients (15.8 ± 5.0) were lower than those who were not (20.4 ± 8.4, P < 0.05). There was no significant difference in serum albumin levels between the two groups. In the successfully weaned patients, the serum albumin concentration was increased from 2.2 ± 0.3 to 2.5 ± 0.4 mg/dL, P < 0.05. Improved nutritional status can help RCC patients to wean from respirators.

COPD: Providing the right treatment for the right patient at the right time

Chronic Obstructive Pulmonary Disease (COPD) is a common disease associated with significant morbidity and mortality that is both preventable and treatable. However, a major challenge in recognizing, preventing, and treating COPD is understanding its complexity. While COPD has historically been characterized as a disease defined by airflow limitation, we now understand it as a multi-component disease with many clinical phenotypes, systemic manifestations, and associated co-morbidities. Evidence is rapidly emerging in our understanding of the many factors that contribute to the pathogenesis of COPD and the identification of "early" or "pre-COPD" which should provide exciting opportunities for early treatment and disease modification. In addition to breakthroughs in our understanding of the origins of COPD, we are optimizing treatment strategies and delivery of care that are showing impressive benefits in patient-centered outcomes and healthcare utilization. This special issue of Respiratory Medicine, "COPD: Providing the Right Treatment for the Right Patient at the Right Time" is a summary of the proceedings of a conference held in Stresa, Italy in April 2022 that brought together international experts to discuss emerging evidence in COPD and Pulmonary Rehabilitation in honor of a distinguished friend and colleague, Claudio Ferdinando Donor (1948-2021). Claudio was a true pioneer in the field of pulmonary rehabilitation and the comprehensive care of individuals with COPD. He held numerous leadership roles in in the field, provide editorial stewardship of several respiratory journals, authored numerous papers, statement and guidelines in COPD and Pulmonary Rehabilitation, and provided mentorship to many in our field. Claudio's most impressive talent was his ability to organize spectacular conferences and symposia that highlighted cutting edge science and clinical medicine. It is in this spirit that this conference was conceived and planned. These proceedings are divided into 4 sections which highlight crucial areas in the field of COPD: (1) New concepts in COPD pathogenesis; (2) Enhancing outcomes in COPD; (3) Non-pharmacologic management of COPD; and (4) Optimizing delivery of care for COPD. These presentations summarize the newest evidence in the field and capture lively discussion on the exciting future of treating this prevalent and impactful disease. We thank each of the authors for their participation and applaud their efforts toward pushing the envelope in our understanding of COPD and optimizing care for these patients. We believe that this edition is a most fitting tribute to a dear colleague and friend and will prove useful to students, clinicians, and researchers as they continually strive to provide the right treatment for the right patient at the right time. It has been our pleasure and a distinct honor to serve as editors and oversee such wonderful scholarly work.

Quality of Life and Stress Levels in Patients under Home Mechanical Ventilation: What Can We Do to Improve Functioning Patients at Home? A Survey Study

BACKGROUND

Home mechanical ventilation (HMV) is becoming more widely available in many countries.

OBJECTIVES

The aim of this study was to measure the health-related quality of life and stress levels of patients ventilated mechanically at home. The relation between quality of life and stress levels was investigated including multiple regression analysis.

METHODS

100 patients treated with HMV in Poland were surveyed with the WHOQOL-BREF questionnaire and Perceived Stress Scale (PSS-10).

RESULTS

26% of patients assessed their quality of life as bad or very bad and 34% as good or very good. Stress levels measured with PSS-10 Scale were high level. For the group of patients with neurological disorders, stress levels were significantly higher than for the group of patients with pulmonological disorders.

CONCLUSIONS

The higher the stress levels of patients, the lower the quality of life in particular domains. Improving the living conditions of HMV patients can influence improving their quality of life.

Long-term home noninvasive ventilation (LTHNIV) in restrictive thoracic diseases: the Italian snapshot

Long-term home noninvasive ventilation (LTHNIV) in restrictive thoracic diseases was explored via the recently published international REINVENT ERS survey. The Italian subset of respondents (ITA-r), the highest above all participating nations, was analyzed and compared to non-Italian respondents (NO-ITA-r). The ITA-r represented 20% of the total answers examined. Ninety-four percent were physicians, whose half worked in a respiratory ICU (RICU). ITA-r mainly worked in community hospitals vs NO-ITA-r who are largely affiliated with university hospitals (p<0.0001). Amyotrophic lateral sclerosis (ALS) was considered the most common medical condition leading to NIV indication by both ITA-r and NO-ITA-r (93% vs 78%, p>0.5). A greater proportion of ITA-r considered MIP/MEP the most important test for NIV initiation as compared to NO-ITA-r (p<0.05). There was no significant difference for both ITA-r and NO-ITA-r as regards the other questions. This study illustrates Italian LTHNIV practices in patients with NMD and it shows some important differences with the other countries' practices but agreement in terms of goals to achieve, reasons to initiate NIV, and practices among the two communities.

Causes of adverse events in home mechanical ventilation: a nursing perspective

Background

Adverse events (AE) are ubiquitous in home mechanical ventilation (HMV) and can jeopardise patient safety. One particular source of error is human interaction with life-sustaining medical devices, such as the ventilator. The objective is to understand these errors and to be able to take appropriate action. With a systematic analysis of the hazards associated with HMV and their causes, measures can be taken to prevent damage to patient health.

Methods

A systematic adverse events analysis process was conducted to identify the causes of AE in intensive home care. The analysis process consisted of three steps. 1) An input phase consisting of an expert interview and a questionnaire. 2) Analysis and categorisation of the data into a root-cause diagram to help identify the causes of AE. 3) Derivation of risk mitigation measures to help avoid AE.

Results

The nursing staff reported that patient transportation, suction and tracheostomy decannulation were the main factors that cause AE. They would welcome support measures such as checklists for care activities and a reminder function, for e.g. tube changes. Risk mitigation measures are given for many of the causes listed in the root-cause diagram. These include measures such as device and care competence, as well as improvements to be made by the equipment providers and manufacturers. The first step in addressing AE is transparency and an open approach to errors and near misses. A systematic error analysis can prevent patient harm through a preventive approach.

Conclusion

Risks in HMV were identified based on a qualitative approach. The collected data was systematically mapped onto a root-cause diagram. Using the root-cause diagram, some of the causes were analysed for risk mitigation. For manufacturers, caregivers and care services requirements for intervention offers the possibility to create a checklist for particularly risky care activities.

Long-term home non-invasive ventilation in chronic hypercapnic chronic obstructive pulmonary disease patients: Real-world impact on lung function, acute exacerbations and survival

INTRODUCTION

Although long-term home non-invasive ventilation (H-NIV) has been used among chronic hypercapnic COPD patients, its clinical benefit is still on debate. We aim to assess the impact of H-NIV in chronic hypercapnic COPD patients.

METHODS

COPD patients who initiated H-NIV between January 2010 and December 2017 were included. Patients with concomitant respiratory disorders were excluded. Acute exacerbation (AE) before and 2 years after H-NIV initiation was assessed as main outcome. Secondary outcomes included lung function and gas exchange parameters. Survival since H-NIV initiation was determined, and factors related with survival were explored.

RESULTS

Seventy-two patients were enrolled. A decrease in partial pressure of carbon dioxide (PaCO₂ ) in arterial blood (p < 0.001) and an improvement of partial pressure of oxygen (PaO₂ ) (p < 0.001) were achieved using a high-intensity H-NIV. Regarding lung function, residual volume (RV) reduced (p = 0.010) and forced-expiratory volume in 1 s (FEV₁ ) improved (p = 0.043) after H-NIV initiation. No significant differences in 6-min walking test (6MWT) were found. Compared with the year before H-NIV initiation, the number of AE diminished in the first and in the second years of follow-up (p < 0.001). The median survival was 79.0 months (95% confidence interval [CI], 52.9-105.1), and the covered distance in 6MWT predicted survival (hazard ratio [HR] = 0.026, p = 0.003) in the multivariate analysis.

CONCLUSIONS

High-intensity H-NIV significantly improved FEV1 and hyperinflation, decreased frequency of AEs and led to a remarkable median survival, which was independently predicted by the walking distance in 6MWT.

REINVENT: ERS International survey on REstrictive thoracic diseases IN long term home noninvasive VENTilation

Background and aim

Little is known about the current use of long-term home noninvasive ventilation (LTHNIV) in restrictive thoracic diseases, including chest wall disorders and neuromuscular disorders (NMD). This study aimed to capture the pattern of LTHNIV in patients with restrictive thoracic diseases via a web-based international survey.

Methods

The survey involved European Respiratory Society (ERS) Assembly 2.02 (NIV-dedicated group), from October to December 2019.

Results

166 (22.2%) out of 748 members from 41 countries responded; 80% were physicians, of whom 43% worked in a respiratory intermediate intensive care unit. The ratio of NMD to chest wall disorders was 5:1, with amyotrophic lateral sclerosis the most frequent indication within NMD (78%). The main reason to initiate LTHNIV was diurnal hypercapnia (71%). Quality of life/sleep was the most important goal to achieve. In 25% of cases, clinicians based their choice of the ventilator on patients' feedback. Among NIV modes, spontaneous-timed pressure support ventilation (ST-PSV) was the most frequently prescribed for day- and night-time. Mouthpieces were the preferred daytime NIV interface, whereas oro-nasal masks the first choice overnight. Heated humidification was frequently added to LTHNIV (72%). Single-limb circuits with intentional leaks (79%) were the most frequently prescribed. Follow-up was most often provided in an outpatient setting.

Conclusions

This ERS survey illustrates physicians' practices of LTHNIV in patients with restrictive thoracic diseases. NMD and, specifically, amyotrophic lateral sclerosis were the main indications for LTHNIV. NIV was started mostly because of diurnal hypoventilation with a primary goal of patient-centred benefits. Bi-level ST-PSV and oro-nasal masks were more likely to be chosen for providing NIV. LTHNIV efficacy was assessed mainly in an outpatient setting.

Home Mechanical Ventilation: A Patient's Perspective Survey Study

Background: An increasing number of patients included in home mechanical ventilation (HMV) care has been under observation for many years. The study aimed to assess the patients opinion concerning the expected and perceived quality of care in an HMV system and a patient’s satisfaction with care. Methods: In 2017, patients treated with HMV were surveyed in Poland with the modified SERVQUAL questionnaire. Results: One hundred correctly completed surveys were analyzed. Patient Satisfaction Index was high. In every examined area, the expectations were statistically significant larger than the perception of the services. The biggest gap was in the tangibility dimension and the smallest gap was in the empathy dimension. Perceived respect and understanding for a patient’s needs are close to the expectations. Conclusions: The level of satisfaction with health care among patients treated with HMV in majority of investigated components is high. Moreover, the difference between perceived and expected quality of health care in the HMV system was relatively small in the opinion of the patients themselves. Further investigations with alternative methods are needed.

Mortality outcomes of patients on chronic mechanical ventilation in different care settings: A systematic review

Objectives

To determine the outcomes of chronically ventilated patients outside the setting of intensive care units.

Design

Systematic review.

Setting and participants

Studies evaluating patients on chronic invasive mechanical ventilation in different care settings.

Methods

A systematic literature search of the PubMed, Embase, Cochrane Library, CINAHL (EBSCOhost), LILACS and Scopus databases from inception to March 27, 2020. Studies reporting mortality outcomes of patients ≥18 years of age on chronic invasive mechanical ventilation in intensive care units and other care settings were eligible for inclusion.

Results

Sixty studies were included in the systematic review. Mortality rates ranged from 13.7% to 77.8% in ICUs (n = 17 studies), 7.8%-51.0% in non-ICUs including step-down units and inpatient wards (n = 26 studies), and 12.0%-91.8% in home or nursing home settings (n = 19 studies). Age was associated with mortality in all care settings. Weaning rates ranged from 10.0% to 78.2% across non-ICU studies. Studies reporting weaning as their primary outcome demonstrated higher success rates in weaning. Home care studies reported low incidences of ventilator failure. None of the studies reported ventilator malfunction as the primary cause of death.

Conclusions and implications

Mortality outcomes across various settings were disparate due to methodological and clinical heterogeneity among studies. However, there is evidence to suggest non-ICU venues of care as a comparable alternative to ICUs for stable, chronically ventilated patients, with the additional benefit of providing specialized weaning programs. By synthesizing the global data on managing chronically ventilated patients in various care settings, this study provides health care systems and providers alternative venue options for the delivery of prolonged ventilatory care in the context of limited ICU resources.

KDIGO Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation

The 2020 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation is intended to assist health care professionals worldwide who evaluate and manage potential candidates for deceased or living donor kidney transplantation. This guideline addresses general candidacy issues such as access to transplantation, patient demographic and health status factors, and immunological and psychosocial assessment. The roles of various risk factors and comorbid conditions governing an individual's suitability for transplantation such as adherence, tobacco use, diabetes, obesity, perioperative issues, causes of kidney failure, infections, malignancy, pulmonary disease, cardiac and peripheral arterial disease, neurologic disease, gastrointestinal and liver disease, hematologic disease, and bone and mineral disorder are also addressed. This guideline provides recommendations for evaluation of individual aspects of a candidate's profile such that each risk factor and comorbidity are considered separately. The goal is to assist the clinical team to assimilate all data relevant to an individual, consider this within their local health context, and make an overall judgment on candidacy for transplantation. The guideline development process followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Guideline recommendations are primarily based on systematic reviews of relevant studies and our assessment of the quality of that evidence, and the strengths of recommendations are provided. Limitations of the evidence are discussed with differences from previous guidelines noted and suggestions for future research are also provided.

Long-Term Mechanical Ventilation: Recommendations of the Swiss Society of Pulmonology

Long-term mechanical ventilation is a well-established treatment for chronic hypercapnic respiratory failure (CHRF). It is aimed at improving CHRF-related symptoms, health-related quality of life, survival, and decreasing hospital admissions. In Switzerland, long-term mechanical ventilation has been increasingly used since the 1980s in hospital and home care settings. Over the years, its application has considerably expanded with accumulating evidence of beneficial effects in a broad range of conditions associated with CHRF. Most frequent indications for long-term mechanical ventilation are chronic obstructive pulmonary disease, obesity hypoventilation syndrome, neuromuscular and chest wall diseases. In the current consensus document, the Special Interest Group of the Swiss Society of Pulmonology reviews the most recent scientific literature on long-term mechanical ventilation and provides recommendations adapted to the particular setting of the Swiss healthcare system with a focus on the practice of non-invasive and invasive home ventilation in adults.

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.

Hypercapnia at Hospital Admission as a Predictor of Mortality

Introduction

Hypercapnia is an indicator of ventilatory exhaustion. There is some disagreement regarding whether hypercapnia is also a predictor of mortality. In this prospective study, we aimed to investigate whether hypercapnia can predict in-hospital and 1-year mortality rates in patients with dyspnea or pulmonary diseases.

Patients and Methods

All patients with dyspnea or pulmonary diseases underwent routine blood gas analysis at hospital admission. During the 12-month enrollment period, 2710 patients were enrolled, and 588 patients with hypercapnia at admission were identified. Of the 1626 normocapnic patients, 62 were randomly selected as controls. In-hospital and 1-year mortality rates were determined.

Results

There were significant increases in mortality rate between acute hypercapnic patients and both chronic hypercapnic patients and normocapnic controls. Their in-hospital mortality rates were 17%, 6.7% and 3.2%, respectively. Their 1-year mortality rates were 32%, 20.2% and 14.5%, respectively. The 1-year mortality rates of hypercapnic patients with different underlying diseases were 24.6% (chronic obstructive pulmonary disease), 28.4% (congestive heart disease), 1.6% (obstructive sleep apnea syndrome/obesity hypoventilation syndrome), 50.9% (pneumonia), 0% (suppressed central respiratory drive, primarily due to opiate abuse) and 22.8% (other conditions).

Discussion

The 1-year mortality rate of patients with acute hypercapnia at hospital admission was 32%, with significant differences compared to chronic hypercapnic patients (20.2%) and normocapnic patients (14.5%). There was a wide range of 1-year mortality rates between the hypercapnic patients with different underlying diseases.

Oxygen therapy in COPD and interstitial lung disease: navigating the knowns and unknowns

Domiciliary oxygen therapy is often prescribed for patients with hypoxaemia due to advanced lung disease, most commonly chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD). Long-term oxygen therapy (LTOT) trials conducted in patients with COPD in the 1980s remain the basis for clinical decisions and guideline recommendations regarding LTOT for patients with non-COPD conditions as there is a lack of high-quality evidence concerning its use in the non-COPD population. There is also a lack of evidence for the use of ambulatory and nocturnal oxygen therapy in patients with isolated exertional and nocturnal hypoxaemia. These deficiencies pose significant challenges in patient care, with consequent discrepancies in guideline recommendations and clinical approaches. In recent years, new studies have been and are currently being conducted to fill the gaps in our understanding and use of domiciliary oxygen therapy for other indications, including ILD. This article provides a comparison of the epidemiology and significance of hypoxaemia in patients with COPD and ILD, with an up-to-date review of current evidence regarding the role of different types of domiciliary oxygen therapy in these conditions.

Despite the significance of hypoxaemia in patients with chronic lung diseases, an up-to-date review shows current evidence for clinical use of domiciliary oxygen therapy remains limitedhttp://bit.ly/33aW31n

Transplant options for end stage chronic obstructive pulmonary disease in the context of multidisciplinary treatments

Lung transplantation (LTx) in advanced stage chronic obstructive pulmonary disease (COPD) patients is associated with significant improvement in lung function and exercise capacity. However, demonstration that the procedure also provides a survival benefit has been more elusive compared to other respiratory conditions. Identification of patients with increased risk of mortality is crucial: a low forced expiratory volume in 1 second (FEV₁) is perhaps the most common reason for referral to a lung transplant center, but in itself is insufficient to identify which COPD patients will benefit from LTx. Many variables have to be considered in the selection of candidates, time for listing, and choice of procedure: age, patient comorbidities, secondary pulmonary hypertension, the balance between individual and community benefit. This review will discuss patient selection, transplant listing, potential benefits and critical issues of bilateral (BLTx) and single lung (SLTx) procedure, donor-to-recipient organ size-matching; furthermore, it will describe LTx outcomes and its effects on recipient survival and quality of life.

[Home non-invasive ventilation for chronic obstructive pulmonary disease]

INTRODUCTION

The benefits of long-term non-invasive ventilation (NIV) in the management of chronic obstructive pulmonary disease (COPD) patients remain controversial.

AIM

To analyze the characteristics of COPD patients under home NIV and to evaluate its impact among this population.

METHODS

We carried out a retrospective study between January 2002 and April 2016 of COPD patients under long-term NIV at "la Rabta" and the Military Hospital.

RESULTS

There were 27 patients with an average age of 64 and a sex ratio (M/F) of 0.92. Active smoking was reported in 96.3%. A persistent hypercapnia following an acute exacerbation of COPD with failure to wean the NIV was the main indication of long-term NIV. We noted a reduction in hospital admissions in the first year of 60% and in intensive care of 83.3% (P<10^-3). There was no non-significant decrease of PaCO₂ (4.5mmHg). There was no modification in FEV 1 and in FVC (P>0.05). The survival rate was 96.3% at 1 year, 83.3% at 2 years and a median survival of 24 months.

CONCLUSIONS

Our study suggests that home NIV contributes to the stabilization of some COPD patients by reducing the hospitalizations rates for exacerbation. More prospective studies are needed to better assess the impact of NIV on survival and quality of life and to better define the COPD patients who require NIV.

Nutritional status and muscle dysfunction in chronic respiratory diseases: stable phase versus acute exacerbations

Nutritional abnormalities are frequent in different chronic respiratory diseases such as chronic obstructive pulmonary disease (COPD), bronchiectasis, cystic fibrosis (CF), interstitial fibrosis and lung cancer, having important clinical consequences. However, nutritional abnormalities often remained underdiagnosed due to the relative lack of awareness of health professionals. Therefore, systematic anthropometry or even better, assessment of body composition, should be performed in all patients with chronic respiratory conditions, especially following exacerbation periods when malnutrition becomes more accentuated. Nutritional abnormalities very often include the loss of muscle mass, which is an important factor for the occurrence of muscle dysfunction. The latter can be easily detected with the specific assessment of muscle strength and endurance, and also negatively influences patients' quality of life and prognosis. Both nutritional abnormalities and muscle dysfunction result from the interaction of several factors, including tobacco smoking, low physical activity-sedentarism, systemic inflammation and the imbalance between energy supply and requirements, which essentially lead to a negative balance between protein breakdown and synthesis. Therapeutic approaches include improvements in lifestyle, nutritional supplementation and training. Anabolic drugs may be administered in some cases.

Respiratory parameters predict poor outcome in COPD patients, category GOLD 2017 B

Background

Respiratory parameters are important predictors of prognosis in the COPD population. Global Initiative for Obstructive Lung Disease (GOLD) 2017 Update resulted in a vertical shift of patients across COPD categories, with category B being the most populous and clinically heterogeneous. The aim of our study was to investigate whether respiratory parameters might be associated with increased all-cause mortality within GOLD category B patients.

Methods

The data were extracted from the Czech Multicentre Research Database, a prospective, noninterventional multicenter study of COPD patients. Kaplan-Meier survival analyses were performed at different levels of respiratory parameters (partial pressure of oxygen in arterial blood [PaO₂], partial pressure of arterial carbon dioxide [PaCO₂] and greatest decrease of basal peripheral capillary oxygen saturation during 6-minute walking test [6-MWT]). Univariate analyses using the Cox proportional hazard model and multivariate analyses were used to identify risk factors for mortality in hypoxemic and hypercapnic individuals with COPD.

Results

All-cause mortality in the cohort at 3 years of prospective follow-up reached 18.4%. Chronic hypoxemia (PaO₂ <7.3 kPa), hypercapnia (PaCO₂ >7.0 kPa) and oxygen desaturation during the 6-MWT were predictors of long-term mortality in COPD patients with forced expiratory volume in 1 second ≤60% for the overall cohort and for GOLD B category patients. Univariate analyses confirmed the association among decreased oxemia (<7.3 kPa), increased capnemia (>7.0 kPa), oxygen desaturation during 6-MWT and mortality in the studied groups of COPD subjects. Multivariate analysis identified PaO₂ <7.3 kPa as a strong independent risk factor for mortality.

Conclusion

Survival analyses showed significantly increased all-cause mortality in hypoxemic and hypercapnic GOLD B subjects. More important, PaO₂ <7.3 kPa was the strongest risk factor, especially in category B patients. In contrast, the majority of the tested respiratory parameters did not show a difference in mortality in the GOLD category D cohort.

Patterns of use, survival and prognostic factors in patients receiving home mechanical ventilation in Western Australia: A single centre historical cohort study

Home mechanical ventilation (HMV) is used in a wide range of disorders associated with chronic hypoventilation. We describe the patterns of use, survival and predictors of death in Western Australia. We identified 240 consecutive patients (60% male; mean age 58 years and body mass index 31 kg m^-2) referred for HMV between 2005 and 2010. The patients were grouped into four categories: motor neurone disorders (MND; 39%), pulmonary disease (PULM; 25%, mainly chronic obstructive pulmonary disease), non-MND neuromuscular and chest wall disorders (NMCW; 21%) and the obesity hypoventilation syndrome (OHS; 15%). On average, the patients had moderate ventilatory impairment (forced vital capacity: 51%predicted), sleep apnoea (apnoea-hypopnea index: 25 events h^-1), sleep-related hypoventilation (transcutaneous carbon dioxide rise of 20 mmHg) and daytime hypercarbia (PCO₂: 54 mmHg). Median durations of survival from HMV initiation were 1.0, 4.2, 9.9 and >11.5 years for MND, PULM, NMCW and OHS, respectively. Independent predictors of death varied between primary indications for HMV; the predictors included (a) age in all groups except for MND (hazard ratios (HRs) 1.03-1.10); (b) cardiovascular disease (HR: 2.35, 95% confidence interval (CI): 1.08-5.10) in MND; (c) obesity (HR: 0.28, 95% CI: 0.13-0.62) and oxygen therapy (HR: 0.33, 95% CI: 0.14-0.79) in PULM; and (d) forced expiratory volume in 1 s (%predicted; HR: 0.93, 95% CI: 0.88-1.00) in OHS.

[Cohort of patients initiated to home ventilation. Observational and prospective study]

Cohort of patients initiated to home ventilation. Observational and prospective study. The effectiveness of home noninvasive ventilation (NIV) for chronic respiratory failure (CRF) is well established. However, few data are available about home NIV prescription and utilization according to the different etiologies of respiratory failure. The ANTADIR Federation, in partnership with the Ventilatory Support Group of the French Speaking Pulmonary Society, has set up a national, observational and multicenter cohort study. The main goal of this study is to analyze the clinical data justifying home NIV prescription in patients with chronic respiratory insufficiency. The secondary objectives will be to assess: the evolution of comorbidities or their occurrence, hospitalizations, NIV compliance, dropout and survival. The population includes patients with chronic respiratory failure newly initiated onto NIV, both in a stable state and following an acute exacerbation who qualify for long-term NIV. Data collected include: diagnosis and comorbidities, age, sex, BMI, biomarkers (hematocrit, arterial blood gases, total CO₂) and functional data (FEV1, VC, TLC), nocturnal results (SaO₂, PtcCO₂), type of ventilator used, ventilator parameters and mask type. Follow-up data will be collected at 4 months, 1 year and 2 years and will include: hospitalizations, changes in prescription, adherence, dropouts and deaths. This work will make it possible to obtain new scientific information on long-term NIV use in France.

A nationwide structure for valid long-term oxygen therapy: 29-year prospective data in Sweden

Background

Long-term oxygen therapy (LTOT) improves prognosis in COPD with severe hypoxemia. However, adherence to criteria for eligibility and quality of LTOT is often insufficient and varies between countries. The aim of this study was to evaluate a national structure for prescription and management of LTOT over three decades in Sweden.

Methods

The study was a prospective, population-based study of 23,909 patients on LTOT from 1987 to 2015 in the Swedish National Register of Respiratory Failure (Swedevox). We assessed the prevalence, incidence, and structure of LTOT; completeness of registration in Swedevox; and validity of prescription and management of LTOT in Sweden according to seven published quality indicators.

Results

LTOT was prescribed by 48 respiratory or medicine units and managed mainly by specialized oxygen nurses. Swedevox had a stable completeness of 85% of patients starting LTOT since 1987. The national incidence of LTOT increased from 3.9 to 14.7/100,000 inhabitants over the time period. In 2015, 2,596 patients had ongoing therapeutic LTOT in the registry, a national prevalence of 31.6/100,000. Adherence to prescription recommendations and fulfillment of quality criteria was stable or improved over time. Of patients starting LTOT in 2015, 88% had severe hypoxemia (partial pressure of arterial oxygen [PaO₂] <7.4 kPa) and 97% had any degree of hypoxemia (PaO₂ <8.0 kPa); 98% were prescribed oxygen ≥15 hours/day or more; 76% had both stationary and mobile oxygen equipment; 75% had a mean PaO₂ >8.0 kPa breathing oxygen; and 98% were non-smokers.

Conclusion

We present a structure for prescription, management, and follow-up of LTOT. The national registry effectively monitored adherence to prescription recommendations and most likely contributed to improved quality of care.

Effects of Hypercapnia and Hypercapnic Acidosis on Hospital Mortality in Mechanically Ventilated Patients

OBJECTIVES

Lung-protective ventilation is used to prevent further lung injury in patients on invasive mechanical ventilation. However, lung-protective ventilation can cause hypercapnia and hypercapnic acidosis. There are no large clinical studies evaluating the effects of hypercapnia and hypercapnic acidosis in patients requiring mechanical ventilation.

DESIGN

Multicenter, binational, retrospective study aimed to assess the impact of compensated hypercapnia and hypercapnic acidosis in patients receiving mechanical ventilation.

SETTINGS

Data were extracted from the Australian and New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation Adult Patient Database over a 14-year period where 171 ICUs contributed deidentified data.

PATIENTS

Patients were classified into three groups based on a combination of pH and carbon dioxide levels (normocapnia and normal pH, compensated hypercapnia [normal pH with elevated carbon dioxide], and hypercapnic acidosis) during the first 24 hours of ICU stay. Logistic regression analysis was used to identify the independent association of hypercapnia and hypercapnic acidosis with hospital mortality.

INTERVENTIONS

Nil.

MEASUREMENTS AND MAIN RESULTS

A total of 252,812 patients (normocapnia and normal pH, 110,104; compensated hypercapnia, 20,463; and hypercapnic acidosis, 122,245) were included in analysis. Patients with compensated hypercapnia and hypercapnic acidosis had higher Acute Physiology and Chronic Health Evaluation III scores (49.2 vs 53.2 vs 68.6; p < 0.01). The mortality was higher in hypercapnic acidosis patients when compared with other groups, with the lowest mortality in patients with normocapnia and normal pH. After adjusting for severity of illness, the adjusted odds ratio for hospital mortality was higher in hypercapnic acidosis patients (odds ratio, 1.74; 95% CI, 1.62-1.88) and compensated hypercapnia (odds ratio, 1.18; 95% CI, 1.10-1.26) when compared with patients with normocapnia and normal pH (p < 0.001). In patients with hypercapnic acidosis, the mortality increased with increasing PCO2 until 65 mm Hg after which the mortality plateaued.

CONCLUSIONS

Hypercapnic acidosis during the first 24 hours of intensive care admission is more strongly associated with increased hospital mortality than compensated hypercapnia or normocapnia.

Oxygen therapy for interstitial lung disease: a systematic review

This review aims to establish the impact of oxygen therapy on dyspnoea, health-related quality of life (HRQoL), exercise capacity and mortality in interstitial lung disease (ILD).

We included studies that compared oxygen therapy to no oxygen therapy in adults with ILD. No limitations were placed on study design or intervention type. Two reviewers independently evaluated studies for inclusion, assessed risk of bias and extracted data. The primary outcome was dyspnoea.

Eight studies evaluated the acute effects of oxygen (n=1509). There was no effect of oxygen therapy on modified Borg dyspnoea score at end exercise (mean difference (MD) −0.06 units, 95% CI −0.24–0.13; two studies, n=27). However, effects on exercise outcomes consistently favoured oxygen therapy. One study showed reduction in dyspnoea at rest with oxygen in patients who were acutely unwell (MD visual analogue scale 30 mm versus 48 mm, p<0.05; n=10). Four studies of long-term oxygen therapy (n=2670) had high risk of bias and no inferences could be drawn.

This systematic review showed no effects of oxygen therapy on dyspnoea during exercise in ILD, although exercise capacity was increased. Future trials should evaluate whether acute improvements in exercise capacity with oxygen can be translated into improved physical activity and HRQoL.

Outdoor activity and performance status as predictors of survival in hypoxaemic chronic obstructive pulmonary disease (COPD)

Background: Performance status has been associated with survival in hypoxaemic chronic obstructive pulmonary disease (COPD) patients on long-term oxygen therapy.

Objective: To determine whether self-reported outdoor activity and performance status are independent predictors of survival in hypoxaemic COPD patients on long-term oxygen therapy.

Design, subjects and main measure: In a prospective design, survival over an eight-year period was studied in 226 Danish patients on long-term oxygen therapy. They were subdivided according to self-reported mobility (&plusmn;outdoor activity) and World Health Organization (WHO) performance status (score 0-4).

Results: A total of 148 patients (65.5%) reported outdoor activity. Compared to the immobile patients, those reporting outdoor activity had higher performance status, higher body mass index and lower duration of oxygen administration. In multivariate analyses adjusting for body mass index, gender and age, both poor performance status and lack of outdoor activity were associated with poor survival (p-levels 0.006 and 0.045, respectively). Lack of outdoor activity was associated with increased mortality (relative risk (RR) and 95% confidence interval of dying was 1.39 (1.01-1.91)) and significantly higher risk was found among those with age in the youngest tertile (less than 66.4 years), the relative risk of dying was 2.18 (1.20-3.95).

Conclusions: This study shows that self-reported performance status and outdoor activity are independent predictors of survival in hypoxaemic COPD patients on long-term oxygen therapy. However, our study suggests that in the most elderly patients, outdoor activity does not predicting survival. Further studies are needed to determine whether interventions that facilitate outdoor activity (e.g., pulmonary rehabilitation) have an effect on survival in this group of patients.

Chronic respiratory care and rehabilitation in France

The development of chronic respiratory care in France faces the same problems of ageing population, technological advancement and budgeting difficulties as other industrially developed countries. We describe the intermediate and home-care systems for treatment of chronic respiratory diseases.

The cost-effectiveness of domiciliary non-invasive ventilation in patients with end-stage chronic obstructive pulmonary disease: a systematic review and economic evaluation

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic progressive lung disease characterised by non-reversible airflow obstruction. Exacerbations are a key cause of morbidity and mortality and place a considerable burden on health-care systems. While there is evidence that patients benefit from non-invasive ventilation (NIV) in hospital during an acute exacerbation, evidence supporting home use for more stable COPD patients is limited. In the U.K., domiciliary NIV is considered on health economic grounds in patients after three hospital admissions for acute hypercapnic respiratory failure.

OBJECTIVE

To assess the clinical effectiveness and cost-effectiveness of domiciliary NIV by systematic review and economic evaluation.

DATA SOURCES

Bibliographic databases, conference proceedings and ongoing trial registries up to September 2014.

METHODS

Standard systematic review methods were used for identifying relevant clinical effectiveness and cost-effectiveness studies assessing NIV compared with usual care or comparing different types of NIV. Risk of bias was assessed using Cochrane guidelines and relevant economic checklists. Results for primary effectiveness outcomes (mortality, hospitalisations, exacerbations and quality of life) were presented, where possible, in forest plots. A speculative Markov decision model was developed to compare the cost-effectiveness of domiciliary NIV with usual care from a UK perspective for post-hospital and more stable populations separately.

RESULTS

Thirty-one controlled effectiveness studies were identified, which report a variety of outcomes. For stable patients, a modest volume of evidence found no benefit from domiciliary NIV for survival and some non-significant beneficial trends for hospitalisations and quality of life. For post-hospital patients, no benefit from NIV could be shown in terms of survival (from randomised controlled trials) and findings for hospital admissions were inconsistent and based on limited evidence. No conclusions could be drawn regarding potential benefit from different types of NIV. No cost-effectiveness studies of domiciliary NIV were identified. Economic modelling suggested that NIV may be cost-effective in a stable population at a threshold of £30,000 per quality-adjusted life-year (QALY) gained (incremental cost-effectiveness ratio £28,162), but this is associated with uncertainty. In the case of the post-hospital population, results for three separate base cases ranged from usual care dominating to NIV being cost-effective, with an incremental cost-effectiveness ratio of less than £10,000 per QALY gained. All estimates were sensitive to effectiveness estimates, length of benefit from NIV (currently unknown) and some costs. Modelling suggested that reductions in the rate of hospital admissions per patient per year of 24% and 15% in the stable and post-hospital populations, respectively, are required for NIV to be cost-effective.

LIMITATIONS

Evidence on key clinical outcomes remains limited, particularly quality-of-life and long-term (> 2 years) effects. Economic modelling should be viewed as speculative because of uncertainty around effect estimates, baseline risks, length of benefit of NIV and limited quality-of-life/utility data.

CONCLUSIONS

The cost-effectiveness of domiciliary NIV remains uncertain and the findings in this report are sensitive to emergent data. Further evidence is required to identify patients most likely to benefit from domiciliary NIV and to establish optimum time points for starting NIV and equipment settings.

FUTURE WORK RECOMMENDATIONS

The results from this report will need to be re-examined in the light of any new trial results, particularly in terms of reducing the uncertainty in the economic model. Any new randomised controlled trials should consider including a sham non-invasive ventilation arm and/or a higher- and lower-pressure arm. Individual participant data analyses may help to determine whether or not there are any patient characteristics or equipment settings that are predictive of a benefit of NIV and to establish optimum time points for starting (and potentially discounting) NIV.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012003286.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Predictors of Mortality in Patients with COPD and Chronic Respiratory Failure: The Quality-of-Life Evaluation and Survival Study (QuESS): A Three-Year Study

Previous studies sought to identify survival or outcome predictors in patients with COPD and chronic respiratory failure, but their findings are inconsistent. We identified mortality-associated factors in a prospective study in 21 centers in 7 countries. Follow-up data were available in 221 patients on home mechanical ventilation and/or long-term oxygen therapy.

MEASUREMENTS

diagnosis, co-morbidities, medication, oxygen therapy, mechanical ventilation, pulmonary function, arterial blood gases, exercise performance were recorded. Health status was assessed using the COPD-specific SGRQ and the respiratory-failure-specific MRF26 questionnaires. Date and cause of death were recorded in those who died. Overall mortality was 19.5%. The commonest causes of death were related to the underlying respiratory diseases. At baseline, patients who subsequently died were older than survivors (p = 0.03), had a lower forced vital capacity (p = 0.03), a higher use of oxygen at rest (p = 0.003) and a worse health status (SGRQ and MRF26, both p = 0.02). Longitudinal analyses over a follow-up period of 3 years showed higher median survival times in patients with use of oxygen at rest less than 1.75 l/min and with a better health status. In contrast, an increase from baseline levels of 1 liter in O2 flow at rest, 1 unit in SGRQ or MRF26, or 1 year increase in age resulted in an increase of mortality of 68%, 2.4%, 1.3%, and 6%, respectively. In conclusion, the need for oxygen at rest, and health status assessment seems to be the strongest predictors of mortality in COPD patients with chronic respiratory failure.

Lung transplantation in chronic obstructive pulmonary disease: patient selection and special considerations

Chronic obstructive pulmonary disease (COPD) is a leading cause of mortality and morbidity. Lung transplantation is one of the few treatments available for end-stage COPD with the potential to improve survival and quality of life. The selection of candidates and timing of listing present challenges, as COPD tends to progress fairly slowly, and survival after lung transplantation remains limited. Though the natural course of COPD is difficult to predict, the use of assessments of functional status and multivariable indices such as the BODE index can help identify which patients with COPD are at increased risk for mortality, and hence which are more likely to benefit from lung transplantation. Patients with COPD can undergo either single or bilateral lung transplantation. Although many studies suggest better long-term survival with bilateral lung transplant, especially in younger patients, this continues to be debated, and definitive recommendations about this cannot be made. Patients may be more susceptible to particular complications of transplant for COPD, including native lung hyperinflation, and development of lung cancer.

Update: Non-Invasive Positive Pressure Ventilation in Chronic Respiratory Failure Due to COPD

Long-term non-invasive positive pressure ventilation (NPPV) has widely been accepted to treat chronic hypercapnic respiratory failure arising from different etiologies. Although the survival benefits provided by long-term NPPV in individuals with restrictive thoracic disorders or stable, slowly-progressing neuromuscular disorders are overwhelming, the benefits provided by long-term NPPV in patients with chronic obstructive pulmonary disease (COPD) remain under question, due to a lack of convincing evidence in the literature. In addition, long-term NPPV reportedly failed in the classic trials to improve important physiological parameters such as arterial blood gases, which might serve as an explanation as to why long-term NPPV has not been shown to substantially impact on survival. However, high intensity NPPV (HI-NPPV) using controlled NPPV with the highest possible inspiratory pressures tolerated by the patient has recently been described as a new and promising approach that is well-tolerated and is also capable of improving important physiological parameters such as arterial blood gases and lung function. This clearly contrasts with the conventional approach of low-intensity NPPV (LI-NPPV) that uses considerably lower inspiratory pressures with assisted forms of NPPV. Importantly, HI-NPPV was very recently shown to be superior to LI-NPPV in terms of improved overnight blood gases, and was also better tolerated than LI-NPPV. Furthermore, HI-NPPV, but not LI-NPPV, improved dyspnea, lung function and disease-specific aspects of health-related quality of life. A recent study showed that long-term treatment with NPPV with increased ventilatory pressures that reduced hypercapnia was associated with significant and sustained improvements in overall mortality. Thus, long-term NPPV seems to offer important benefits in this patient group, but the treatment success might be dependent on effective ventilatory strategies.

Nocturnal mechanical ventilation for chronic hypoventilation in patients with neuromuscular and chest wall disorders

BACKGROUND

Chronic alveolar hypoventilation is a common complication of many neuromuscular and chest wall disorders. Long-term nocturnal mechanical ventilation is commonly used to treat it. This is a 2014 update of a review first published in 2000 and previously updated in 2007.

OBJECTIVES

To examine the effects on mortality of nocturnal mechanical ventilation in people with neuromuscular or chest wall disorders. Subsidiary endpoints were to examine the effects of respiratory assistance on improvement of chronic hypoventilation, sleep quality, hospital admissions and quality of life.

SEARCH METHODS

We searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE and EMBASE on 10 June 2014. We contacted authors of identified trials and other experts in the field.

SELECTION CRITERIA

We searched for quasi-randomised or randomised controlled trials of participants of all ages with neuromuscular or chest wall disorder-related stable chronic hypoventilation of all degrees of severity, receiving any type and any mode of long-term nocturnal mechanical ventilation. The primary outcome measure was one-year mortality and secondary outcomes were unplanned hospital admission, short-term and long-term reversal of hypoventilation-related clinical symptoms and daytime hypercapnia, improvement of lung function and sleep breathing disorders.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology to select studies, extract data and assess the risk of bias in included studies.

MAIN RESULTS

The 10 eligible trials included a total of 173 participants. Roughly half of the trials were at low risk of selection, attrition or reporting bias, and almost all were at high risk of performance and detection bias. Four trials reported mortality data in the long term. The pooled risk ratio (RR) of dying was 0.62 (95% confidence interval (CI) 0.42 to 0.91, P value = 0.01) in favour of nocturnal mechanical ventilation compared to spontaneous breathing. There was considerable and significant heterogeneity between the trials, possibly related to differences between the study populations. Information on unplanned hospitalisation was available from two studies. The corresponding pooled RR was 0.25 (95% CI 0.08 to 0.82, P value = 0.02) in favour of nocturnal mechanical ventilation. For most of the outcome measures there was no significant long-term difference between nocturnal mechanical ventilation and no ventilation. Most of the secondary outcomes were not assessed in the eligible trials. Three out of the 10 trials, accounting for 39 participants, two with a cross-over design and one with two parallel groups, compared volume- and pressure-cycled non-invasive mechanical ventilation in the short term. From the only trial (16 participants) on parallel groups, there was no difference in mortality (one death in each arm) between volume- and pressure-cycled mechanical ventilation. Data from the two cross-over trials suggested that compared with pressure-cycled ventilation, volume-cycled ventilation was associated with less sleep time spent with an arterial oxygen saturation below 90% (mean difference (MD) 6.83 minutes, 95% CI 4.68 to 8.98, P value = 0.00001) and a lower apnoea-hypopnoea (per sleep hour) index (MD -0.65, 95% CI -0.84 to -0.46, P value = 0.00001). We found no study that compared invasive and non-invasive mechanical ventilation or intermittent positive pressure versus negative pressure ventilation.

AUTHORS' CONCLUSIONS

Current evidence about the therapeutic benefit of mechanical ventilation is of very low quality, but is consistent, suggesting alleviation of the symptoms of chronic hypoventilation in the short term. In four small studies, survival was prolonged and unplanned hospitalisation was reduced, mainly in participants with motor neuron diseases. With the exception of motor neuron disease and Duchenne muscular dystrophy, for which the natural history supports the survival benefit of mechanical ventilation against no ventilation, further larger randomised trials should assess the long-term benefit of different types and modes of nocturnal mechanical ventilation on quality of life, morbidity and mortality, and its cost-benefit ratio in neuromuscular and chest wall diseases.

Systematic analysis of blood cell transcriptome in end-stage chronic respiratory diseases

Background

End-stage chronic respiratory diseases (CRD) have systemic consequences, such as weight loss and susceptibility to infection. However the mechanisms of such dysfunctions are as yet poorly explained. We hypothesized that the genes putatively involved in these mechanisms would emerge from a systematic analysis of blood mRNA profiles from pre-transplant patients with cystic fibrosis (CF), pulmonary hypertension (PAH), and chronic obstructive pulmonary disease (COPD).

Methods

Whole blood was first collected from 13 patients with PAH, 23 patients with CF, and 28 Healthy Controls (HC). Microarray results were validated by quantitative PCR on a second and independent group (7PAH, 9CF, and 11HC). Twelve pre-transplant COPD patients were added to validate the common signature shared by patients with CRD for all causes. To further clarify a role for hypoxia in the candidate gene dysregulation, peripheral blood mononuclear cells from HC were analysed for their mRNA profile under hypoxia.

Results

Unsupervised hierarchical clustering allowed the identification of 3 gene signatures related to CRD. One was common to CF and PAH, another specific to CF, and the final one was specific to PAH. With the common signature, we validated T-Cell Factor 7 (TCF-7) and Interleukin 7 Receptor (IL-7R), two genes related to T lymphocyte activation, as being under-expressed. We showed a strong impact of the hypoxia on modulation of TCF-7 and IL-7R expression in PBMCs from HC under hypoxia or PBMCs from CRD. In addition, we identified and validated genes upregulated in PAH or CF, including Lectin Galactoside-binding Soluble 3 and Toll Like Receptor 4, respectively.

Conclusions

Systematic analysis of blood cell transcriptome in CRD patients identified common and specific signatures relevant to the systemic pathologies. TCF-7 and IL-7R were downregulated whatever the cause of CRD and this could play a role in the higher susceptibility to infection of these patients.

Overweight and obesity may lead to under-diagnosis of airflow limitation: findings from the Copenhagen City Heart Study

BACKGROUND

The prevalence of obesity has increased during the last decades and varies from 10-20% in most European countries to approximately 32% in the United States. However, data on how obesity affects the presence of airflow limitation (AFL) defined as a reduced ratio between forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) are scarce.

METHODS

Data was derived from the third examination of the Copenhagen City Heart Study from 1991 until 1994 (n = 10,135). We examine the impact of different adiposity markers (weight, body mass index (BMI), waist circumference, waist-hip ratio, and abdominal height) on AFL. AFL was defined in four ways: FEV1/FVC ratio < 0.70, FEV1/FVC ratio < lower limit of normal (LLN), FEV1/FVC ratio <0.70 including at least one respiratory symptom, and FEV1/FVC ratio < LLN and FEV1% of predicted < LLN.

RESULTS

All adiposity markers were positively and significantly associated with FEV1/FVC independent of age, sex, height, smoking status, and cumulative tobacco consumption. Among all adiposity markers, BMI was the strongest predictor of FEV1/FVC. FEV1/FVC increased with 0.04 in men and 0.03 in women, as BMI increased with 10 units (kg · m-2). Consequently, diagnosis of AFL was significantly less likely in subjects with BMI ≥ 25 kg · m-2 with odds ratios 0.63 or less compared to subjects with BMI between 18.5-24.9 kg · m-2 when AFL was defined as FEV1/FVC < 0.70.

CONCLUSION

High BMI reduces the probability of AFL. Ultimately, this may result in under-diagnosis and under-treatment of COPD among individuals with overweight and obesity.

Serial Measurements of Arterial Oxygen Tension are Associated with Mortality in COPD

BACKGROUND

Knowledge on factors associated with mortality can help identify patients with COPD that might benefit from close monitoring and intervention. Arterial blood gases (ABGs) are related to mortality, but both arterial tension of oxygen (PaO2) and arterial tension of carbon dioxide (PaCO2) vary over time. The aim of our study was to investigate the association between repeatedly measured ABGs and mortality in men and women with COPD.

METHODS

A cohort of 419 Norwegian subjects with COPD, GOLD stage II-IV, aged 40-75, was followed up with up to seven ABGs, measured during stable phase for three years. Cox proportional hazard models were used to quantify the relationship between both single and repeatedly measured ABGs and all-cause mortality after five years, adjusting for age, sex, and the updated BODE index.

RESULTS

A total of 64 subjects died during follow-up. Mean initial arterial oxygen tension (standard deviation) was significantly higher in survivors compared to deceased, with PaO2 (in kPa) 9.4 (1.1) versus 8.8 (1.2), p<0.001. Corresponding numbers for PaCO2 were 5.3 (0.5) and 5.5 (0.7), p < 0.001. In analyses adjusting for age, sex, and the updated BODE index hazard ratios - HR(95% confidence intervals) - for all-cause mortality were 0.73 (0.55, 0.97) and 1.58 (0.90, 2.76) for repeated measures of PaO2 and PaCO2, respectively.

CONCLUSION

Both arterial oxygen and carbon dioxide tension were related to mortality in this study, and arterial oxygen tension added prognostic information to the updated BODE index in COPD.

Survival of patients with chronic respiratory failure on long-term oxygen therapy and or non-invasive ventilation at home

BACKGROUND & AIMS

Chronic respiratory failure (CRF) is the common fate of respiratory diseases where systemic effects contribute to outcomes. In a prospective cohort of home-treated patients with CRF, we looked for predictors of long-term survival including respiratory, nutritional and inflammatory dimensions.

METHODS

637 stable outpatients with CRF, 397 men, 68 ± 11 years, on long-term oxygen therapy and/or non-invasive ventilation from 21 chest clinics were enrolled and followed over 53 ± 31 months. CRF resulted from Chronic Obstructive Pulmonary Disease (COPD) in 48.5%, restrictive disorders 32%, mixed (obstructive and restrictive patterns) respiratory failure 13.5%, bronchiectasis 6%. Demographic characteristics, smoking habits, underlying respiratory diseases, forced expiratory volume in one second (FEV1), forced vital capacity (FVC), arterial blood gases, 6-min walking distance (6MWD), hemoglobin, body mass index (BMI), serum albumin, transthyretin, C-reactive protein (CRP), history of respiratory assistance, antibiotic and oral corticosteroid use during the previous year were recorded.

RESULTS

322 deaths occurred during the follow-up. One-, five- and 8-year actuarial survival was 89%, 56% and 47%. By Cox univariate analysis, age, respiratory disease, PaO2, PaCO2, FEV1/FVC, BMI, 6MWD, activity score, type and length of home respiratory assistance, smoking habits, oral corticosteroid and antibiotic uses, albumin, transthyretin, hemoglobin and CRP levels were associated with survival. Multivariate analysis identified eight independent markers of survival: age, FEV1/FVC, PaO2, PaCO2, 6MWD, BMI, serum transthyretin, CRP ≥ 5 mg/l.

CONCLUSIONS

In CRF, whatever the underlying diseases, besides the levels of obstructive ventilatory defect and gas exchange failure, 6MWD, BMI, serum transthyretin and CRP ≥ 5 mg/l predicted long-term survival identifying potential targets for nutritional rehabilitation.

Identification of three exercise-induced mortality risk factors in patients with COPD

The survival rate of chronic obstructive pulmonary disease (COPD) patients with severely reduced exercise capacity is extremely low. We recently identified three life-threatening pathophysiological conditions during cardiopulmonary exercise testing (CPET): (1) exercise-induced hypoxemia, (2) sympathetic overactivity, and (3) progressive respiratory acidosis at low-intensity exercise. The present prospective observation study aimed to determine whether these parameters constitute risk factors of mortality in moderate-to-very severe COPD. Ninety-six COPD patients were followed-up, monthly, for >3 years. Subsequently, spirometry and CPET were performed to examine parameters of exercise-induced hypoxemia ([PaO2 slope, mmHg/L · min(-1)] = Decrease in PaO2/ΔV˙ O2 (Difference in ΔV˙ O2 between at rest and at peak exercise)), progression of acidosis ([ΔpH/ΔV˙ O2,/L · min(-1)] = Decrease in pH/ΔV˙ O2), and sympathetic overactivity ([Δnorepinephrine (NE)/ΔV˙ O2, ng/mL/L · min(-1)] = Increase in NE/ΔV˙ O2). Univariate analysis revealed a significant association between the three conditions with increased mortality. Kaplan-Meier analysis showed that the quartile combining the steepest PaO2 slope (≤-55 mmHg/ΔV˙ O2 [L/min]), steepest decrease in arterial blood pH (≤ -1.72/ΔV˙ O2 [L/min]), and most rapid increase in plasma NE level (≥ 5.2 ng/VO2 [L/min]) during incremental exercise was associated with higher all-cause mortality. These conditions showed cumulative effects on COPD patients' survival. Multivariate analyses revealed that these three life-threatening factors are also independent predictors of mortality based on age, heart rate and PaO2 at rest, body mass index, and forced expiratory volume in 1 s. Thus, these new exercise-induced mortality risk factors may lead to more efficient pulmonary rehabilitation programs for COPD patients based on patient-specific exercise-induced pathophysiological profiles.

[Long-term oxygen therapy in France, 2006-2011]

OBJECTIVE

The study aimed to describe the main characteristics of people treated with long-term oxygen therapy (LTOT) and the trends between 2006 and 2011 for prevalence and incidence.

METHODS

Data were provided from a sample comprising 1/97 of the permanent beneficiaries of the French health insurance. The sample contains anonymous socio-demographic characteristics and data on health care reimbursements. The analyses were carried out among adults aged 20 years and above who had received benefits on account of LTOT.

RESULTS

In 2011, 2.6% of adults were treated with LTOT, corresponding to around 135,000 people. The crude incidence rate was 0.9‰. The prescription of LTOT included LTOT alone (70%), LTOT associated with assisted ventilation (23%) and LTOT associated with continuous positive airway pressure (7%). About 45% of the patients were supported financially in the long-term illness program of the French Social Security because of severe chronic respiratory failure. Between 2006 and 2011, the age-adjusted prevalence rates increased by 2.9% per year in men and by 6.7% per year in women. The age-adjusted incidence rates remained stable in men (+1.6% per year, P=0.45) but increased in women (+4.7% per year, P=0.04). The median survival was 27 months.

CONCLUSION

This analysis of the data demonstrates an increasing burden associated with LTOT in France from 2006 to 2011.

Hypo- and hypercapnia predict mortality in oxygen-dependent chronic obstructive pulmonary disease: a population-based prospective study

BACKGROUND

The prognostic role of the arterial blood gas tension of carbon dioxide (PaCO2) in severe Chronic Obstructive Pulmonary Disease (COPD) remains unknown. The aim of this study was to estimate the association between PaCO2 and mortality in oxygen-dependent COPD.

METHODS

National prospective study of patients starting long-term oxygen therapy (LTOT) for COPD in Sweden between October 1, 2005 and June 30, 2009, with all-cause mortality as endpoint. The association between PaCO2 while breathing air, PaCO2 (air), and mortality was estimated using Cox regression adjusted for age, sex, arterial blood gas tension of oxygen (PaO2), World Health Organization performance status, body mass index, comorbidity, and medications.

RESULTS

Of 2,249 patients included, 1,129 (50%) died during a median 1.1 years (IQR 0.6-2.0 years) of observation. No patient was lost to follow-up. PaCO2 (air) independently predicted adjusted mortality (p < 0.001). The association with mortality was U-shaped, with the lowest mortality at approximately PaCO2 (air) 6.5 kPa and increased mortality at PaCO2 (air) below 5.0 kPa and above 7.0 kPa.

CONCLUSION

In oxygen-dependent COPD, PaCO2 (air) is an independent prognostic factor with a U-shaped association with mortality.

Trends in long-term oxygen therapy for COPD in Denmark from 2001 to 2010

OBJECTIVES

To evaluate changes in demographics, incidence, prevalence, treatment modalities, and survival of COPD patients on long-term oxygen therapy (LTOT) from year 2001-2010 in Denmark.

METHODS

All 14,965 COPD patients with COPD treated LTOT in Denmark in the period 2001-2010.

RESULTS

During the study period, the incidence and prevalence of COPD patients on LTOT increased from 30.5 to 32.2 per 100.000, and from 42.0 to 48.1 per 100.000, respectively. Mean age of patients increased from 73.4 to 74.8 years, P < 0.001. An increasing number of patients were prescribed LTOT in connection with discharge after hospitalisation for an exacerbation (2001 vs. 2010: 76.5% vs. 91.7%, P < 0.001); were prescribed oxygen 15-24 h/day (85.8% vs. 89.5%, P < 0.001); had mobile oxygen (56.4% vs. 94.2%, P < 0.001), and stopped LTOT alive within 6 months (20.6% vs. 30.8%, P < 0.001). Ninety-nine percent of the patients received oxygen concentrator or liquid oxygen with no change in the study period (P = 0.66). The median survival on LTOT increased insignificantly from 16.5 to 17.8 months (P = 0.12). Women had a lower risk of dying compared with men, with an adjusted hazard ratio of 0.81 (95% confidence interval (CI) 0.78-0.84), P < 0.001). During the study period, the risk of death for women, compared to men, decreased significantly with a hazard ratio of 0.978 (95% CI: 0.964-0.992) per calendar year.

CONCLUSIONS

The incidence of COPD patients on LTOT in Denmark has levelled of during recent years, and the quality of prescribing LTOT and follow up has improved. Women had better survival than men, and this difference has increased during the study period.

Continuous positive airway pressure and noninvasive ventilation adherence in children

BACKGROUND

Adherence to continuous positive airway pressure (CPAP) and noninvasive ventilation (NIV) is crucial for the successful treatment of sleep-disordered breathing. The aim of our study was to analyze the adherence of children to long-term home CPAP/NIV treatment.

METHODS

We analyzed data from all consecutive patients older than the age of 2years, in whom CPAP/NIV treatment was initiated in a specialized pediatric NIV and in those who were receiving CPAP/NIV treatment at home for at least 1month. Data of the memory cards of the ventilators and nocturnal gas exchange were analyzed during a routine CPAP/NIV overnight control in the hospital. CPAP/NIV adherence during the previous month was analyzed according to patient's age, ventilatory mode, type of interface, nocturnal gas exchange, and duration of treatment.

RESULTS

The data of 62 children (mean age, 10±5years) with obstructive sleep apnea (n=51) treated with CPAP and neuromuscular disease (n=6) or lung diseases (n=5) treated with NIV were analyzed. Mean adherence was 8:17±2:30h:min per night, and the results did not significantly differ between CPAP and NIV adherence. Seventy-two percent of the patients used their device >8h per night. The mean number of nights of CPAP/NIV use during the last month was 26±5 nights per month. Treatment adherence was not correlated to age, the type of underlying disease, the type of interface (nasal, facial mask, or nasal cannula), nocturnal gas exchange, and duration of CPAP/NIV treatment.

CONCLUSION

Long-term CPAP/NIV adherence at home was extremely high in this group of children followed in a pediatric NIV unit. This finding may explain the lack of effect of the interface, nocturnal gas exchange, and duration of CPAP/NIV treatment.