The Severe Respiratory Insufficiency Questionnaire scored best in the assessment of health-related quality of life in chronic obstructive pulmonary disease

Clinical evidence and technical aspects of innovative technology and monitoring of chronic NIV in COPD: a narrative review

INTRODUCTION

Chronic nocturnal noninvasive ventilation (NIV) improves outcomes in COPD patients with chronic hypercapnic respiratory failure. The aim of chronic NIV in COPD is to control chronic hypercapnic respiratory insufficiency and reduce symptoms of nocturnal hypoventilation, thereby improving quality of life. Chronic NIV care is more and more offered exclusively at home, enabling promising outcomes in terms of patient and caregiver satisfaction, hospital care consumption and cost reduction. Yet, to achieve and maintain optimal ventilation, during adaptation and follow-up, effective feasible (home) monitoring poses a significant challenge.

AREAS COVERED

Comprehensive monitoring of COPD patients receiving chronic NIV requires integrating data from ventilators and assessment of the patient's status including gas exchange, sleep quality, and patient-reported outcomes. The present article describes the physiological background of monitoring during NIV and aims to provide an overview of existing methods for monitoring, assessing their reliability and clinical relevance.

EXPERT OPINION

Patients on chronic NIV are 'ideal' candidates for home monitoring; the advantages of transforming hospital to home care are huge for patients and caregivers and for healthcare systems facing increasing patient numbers. Despite the multitude of available monitoring methods, identifying and characterizing the most relevant parameters associated with optimal patient well-being remains unclear.

Validity and reliability of the Dutch version of the S3-NIV questionnaire to evaluate long-term noninvasive ventilation

OBJECTIVES

Noninvasive ventilation (NIV) is an effective treatment for chronic respiratory failure (CRF). Patient-centered outcomes need to be evaluated regularly and the S3-NIV questionnaire seems an applicable tool. We translated this short, self-administered questionnaire into a Dutch version and tested its construct validity and reliability.

METHODS

An observational study was conducted, including 127 stable long-term NIV users with CRF or complex sleep related breathing disorders due to different underlying diseases: chronic obstructive pulmonary disease (25%), slowly progressive neuromuscular disorders (35%), rapidly progressive neuromuscular disorders (12%) and 'other disorders' (28%) including complex sleep apnea and obesity hypoventilation syndrome. Construct validity and reliability were tested.

RESULTS

The Dutch version of the questionnaire was obtained after a translation and back-translation process. Internal consistency of the total score was good (Cronbach's α coefficient of 0.78) as well as for the 'respiratory symptoms' subdomain and the 'sleep and side effects' subdomain (Cronbach's α coefficient of 0.78 and 0.69, respectively). The reproducibility was excellent with an intraclass correlation of 0.89 (95% CI 0.87-0.93). Construct validity was good for the 'respiratory symptoms' subdomain.

CONCLUSION

The Dutch S3-NIV questionnaire is a reliable and valid tool to evaluate symptoms, sleep, and NIV related side effects in long-term NIV users.

Home ventilation for patients with end-stage chronic obstructive pulmonary disease

PURPOSE OF THE REVIEW

The number of patients with end-stage chronic obstructive pulmonary disease (COPD) treated with chronic non-invasive ventilation (NIV) has greatly increased. In this review, the authors summarize the evidence for nocturnal NIV and NIV during exercise. The authors discuss the multidisciplinary and advanced care of patients with end-stage COPD treated with NIV.

RECENT FINDINGS

Nocturnal NIV improves gas exchange, health-related quality of life and survival in stable hypercapnic COPD patients. Improvements in care delivery have been achieved by relocating care from the hospital to home based; home initiation of chronic NIV is feasible, non-inferior regarding efficacy and cost-effective compared to in-hospital initiation. However, the effect of NIV on symptoms is variable, and applying optimal NIV for end-stage COPD is complex. While exercise-induced dyspnoea is a prominent complaint in end-stage COPD, nocturnal NIV will not change this. However, NIV applied solely during exercise might improve exercise tolerance and dyspnoea. While chronic NIV is often a long-standing treatment, patient expectations should be discussed early and be managed continuously during the treatment. Further, integration of advance care planning requires a multidisciplinary approach.

SUMMARY

Although chronic NIV is an effective treatment in end-stage COPD with persistent hypercapnia, there are still important questions that need to be answered to improve care of these severely ill patients.

New insights into acute and chronic respiratory failure: highlights from the Respiratory Failure and Mechanical Ventilation Conference 2022

The European Respiratory Society (ERS) is home to clinicians, scientists and students interested in respiratory medicine. In June 2022, the Society organised the second edition of the “Respiratory Failure and Mechanical Ventilation Conference”. This event focuses on clinical and scientific aspects of acute and chronic respiratory failure. Faculty and participants from 50 countries around the globe met in Berlin, although this time most of the sessions could also be accessed online. Participants with very diverse backgrounds, including medicine, nursing, physiotherapy and industry, discussed all aspects of respiratory failure including physiology, interventions for respiratory support, advanced diagnostic techniques, quality of life, and end of life care. Our common ground was passion for respiratory failure. The quality of the sessions during this 3-day conference was outstanding, and many of the presentations are still available for conference participants through the ERS website. However, the conference organisers felt that many of the topics discussed deserved an even broader audience.

Highlights from the Respiratory Failure and Mechanical Ventilation Conference 2022 https://bit.ly/3HMWKTp

Cost-effectiveness of home non-invasive ventilation in COPD group GOLD D patients

Introduction. Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality, estimated to be the third most common cause of death by 2020. The natural evolution of the disease is characterized by frequent exacerbations, severe exacerbations evolving with respiratory acidosis. Introducing home non-invasive ventilation (NIV) in the management of COPD group GOLD (Global Initiative for Chronic Obstructive Lung Disease) D patients generates supplementary costs, but the decreasing of the number of severe exacerbations will decrease the costs of drug treatment and hospitalization. This balance can be verified through a careful study of cost-effectiveness through modern methods of assessing the costs and years of life gained in relation to quality of life. Material and method. This prospective study took place in the Emergency Department of the Bihor County Clinical Emergency Hospital, Oradea, between 01 October 2017 – 31 October2018, with a follow-up period of 2 years. We included 36 Group risk D COPD patients, presented with severe exacerbation that required NIV; the patients were divided into two study groups according to the treatment scheme after discharge (standard medication according to GOLD guidelines and long-term oxygen therapy - LTOT vs. LTOT + NIV). We follow-up at 2 years with the study group, and analyze the following: number of exacerbations (moderate and severe), number of hospitalizations, mortality rate in two years, average costs for the treatment of exacerbations and for stable COPD periods, quality adjusted life year (QALY). Results and discussions. From 36 enrolled, 10 patients benefited from home NIV. The number of exacerbations was significantly lower in the NIV group compared with the LTOT group (1.72±0.79 vs 3.54±1.18). The incremental cost-effectiveness ratio (ICER) showed a net gain of 31% from gross product (GDP) per capita (5,641.71 ± 1,737.0-euro vs 9,272.3 ± 3,681.9 euro) per quality adjusted life year (QALY) for each patient. Conclusions. Introduction home-NIV demonstrated clinical improvement and higher cost-effectiveness over LTOT alone in Class Risk D, COPD patients after discharge following a severe exacerbation. Keywords: chronic obstructive pulmonary disease, non-invasive ventilation, cost-effectiveness, quality adjusted life year,

A home-based pulmonary rehabilitation mHealth system to enhance the exercise capacity of patients with COPD: development and evaluation

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) experience deficits in exercise capacity and physical activity as their disease progresses. Pulmonary rehabilitation (PR) can enhance exercise capacity of patients and it is crucial for patients to maintain a lifestyle which is long-term physically active. This study aimed to develop a home-based rehabilitation mHealth system incorporating behavior change techniques (BCTs) for COPD patients, and evaluate its technology acceptance and feasibility.

METHODS

Guided by the medical research council (MRC) framework the process of this study was divided into four steps. In the first step, the prescription was constructed. The second step was to formulate specific intervention functions based on the behavior change wheel theory. Subsequently, in the third step we conducted iterative system development. And in the last step two pilot studies were performed, the first was for the improvement of system functions and the second was to explore potential clinical benefits and validate the acceptance and usability of the system.

RESULTS

A total of 17 participants were enrolled, among them 12 COPD participants completed the 12-week study. For the clinical outcomes, Six-Minute Walk Test (6MWT) showed significant difference (P = .023) over time with an improvement exceeded the minimal clinically important difference (MCID). Change in respiratory symptom (CAT score) was statistically different (P = .031) with a greater decrease of - 3. The mMRC levels reduced overall and showed significant difference. The overall compliance of this study reached 82.20% (± 1.68%). The results of questionnaire and interviews indicated good technology acceptance and functional usability. The participants were satisfied with the mHealth-based intervention.

CONCLUSIONS

This study developed a home-based PR mHealth system for COPD patients. We showed that the home-based PR mHealth system incorporating BCTs is a feasible and acceptable intervention for COPD patients, and COPD patients can benefit from the intervention delivered by the system. The proposed system played an important auxiliary role in offering exercise prescription according to the characteristics of patients. It provided means and tools for further individuation of exercise prescription in the future.

Chronic non-invasive ventilation for chronic obstructive pulmonary disease

BACKGROUND

Chronic non-invasive ventilation (NIV) is increasingly being used to treat people with COPD who have respiratory failure, but the evidence supporting this treatment has been conflicting.

OBJECTIVES

To assess the effects of chronic non-invasive ventilation at home via a facial mask in people with COPD, using a pooled analysis of IPD and meta-analysis.

SEARCH METHODS

We searched the Cochrane Airways Register of Trials, MEDLINE, Embase, PsycINFO, CINAHL, AMED, proceedings of respiratory conferences, clinical trial registries and bibliographies of relevant studies. We conducted the latest search on 21 December 2020.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing chronic NIV for at least five hours per night for three consecutive weeks or more (in addition to standard care) versus standard care alone, in people with COPD. Studies investigating people initiated on NIV in a stable phase and studies investigating NIV commenced after a severe COPD exacerbation were eligible, but we reported and analysed them separately. The primary outcomes were arterial blood gases, health-related quality of life (HRQL), exercise capacity (stable COPD) and admission-free survival (post-exacerbation COPD). Secondary outcomes for both populations were: lung function, COPD exacerbations and admissions, and all-cause mortality. For stable COPD, we also reported respiratory muscle strength, dyspnoea and sleep efficiency.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. After inclusion of a study, we requested the IPD. We analysed continuous and time-to-event data using linear- and cox-regression mixed-effect models with a random effect on study level. We analysed dichotomous IPD using generalised estimating equations. We adjusted all models for age and sex. We assessed changes in outcomes after three and 12 months.  We also conducted a meta-analysis on aggregated trial data.

MAIN RESULTS

We included 14 new RCTs in this review update, in addition to the seven previously included. Seventeen studies investigated chronic NIV in stable COPD and four studies investigated chronic NIV commenced after a severe COPD exacerbation. Three studies compared NIV to sham continuous positive airway pressure (2 to 4 cmH₂O). Seven studies used a nasal mask, one study used an oronasal mask and eight studies used both interfaces. Five studies did not report the interface. The majority of trials (20/21) were at high risk of performance bias due to an unblinded design. We considered 11 studies to have a low risk of selection bias and 13 to have a low risk of attrition bias. We collected and analysed the IPD from 13 stable COPD studies (n = 778, 68% of the participants included) and from three post-exacerbation studies (n = 364, 96% of the participants included). In the stable COPD group, NIV probably results in a minor benefit on the arterial partial pressure of oxygen (PaO₂) after three months (adjusted mean difference (AMD) 0.27 kPa, 95% CI 0.04 to 0.49; 9 studies, 271 participants; moderate-certainty evidence), but there was little to no benefit at 12 months (AMD 0.09 kPa, 95% CI -0.23 to 0.42; 3 studies, 171 participants; low-certainty evidence). The arterial partial pressure of carbon dioxide (PaCO₂) was reduced in participants allocated to NIV after three months (AMD -0.61 kPa, 95% CI -0.77 to -0.45; 11 studies, 475 participants; high-certainty evidence) and persisted up to 12 months (AMD -0.42 kPa, 95% CI -0.68 to -0.16; 4 studies, 232 participants; high-certainty evidence).  Exercise capacity was measured with the 6-minute walking distance (minimal clinical important difference: 26 m). There was no clinically relevant effect of NIV on exercise capacity (3 months: AMD 15.5 m, 95% CI -0.8 to 31.7; 8 studies, 330 participants; low-certainty evidence; 12 months: AMD 26.4 m, 95% CI -7.6 to 60.5; 3 studies, 134 participants; very low-certainty evidence). HRQL was measured with the Severe Respiratory Insufficiency and the St. Georges's Respiratory Questionnaire and may be improved by NIV, but only after three months (3 months: standardised mean difference (SMD) 0.39, 95% CI 0.15 to 0.62; 5 studies, 259 participants; very low-certainty evidence; 12 months: SMD 0.15, 95% CI -0.13 to 0.43; 4 studies, 200 participants; very low-certainty evidence). Lastly, the risk for all-cause mortality is likely reduced by NIV (adjusted hazard ratio (AHR) 0.75, 95% CI 0.58 to 0.97; 3 studies, 405 participants; moderate-certainty evidence). In the post-exacerbation COPD group, there was little to no benefit on the PaO₂ after three months, but there may be a slight decrease after 12 months (3 months: AMD -0.10 kPa, 95% CI -0.65 to 0.45; 3 studies, 234 participants; low-certainty evidence; 12 months: -0.27 kPa, 95% CI -0.86 to 0.32, 3 studies; 170 participants; low-certainty evidence). The PaCO₂ was reduced by NIV at both three months (AMD -0.40 kPa, 95% CI -0.70 to -0.09; 3 studies, 241 participants; moderate-certainty evidence) and 12 months (AMD -0.52 kPa, 95% CI -0.87 to -0.18; 3 studies, 175 participants; high-certainty evidence). NIV may have little to no benefit on HRQL (3 months: SMD 0.25, 95% CI -0.01 to 0.51; 2 studies, 219 participants; very low-certainty evidence; 12 months: SMD 0.25, 95% -0.06 to 0.55; 2 studies, 164 participants; very low-certainty evidence). Admission-free survival seems improved with NIV (AHR 0.71, 95% CI 0.54 to 0.94; 2 studies, 317 participants; low-certainty evidence), but the risk for all-cause mortality does not seem to improve (AHR 0.97, 95% CI 0.74 to 1.28; 2 studies, 317 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

Regardless of the timing of initiation, chronic NIV improves daytime hypercapnia. In addition, in stable COPD, survival seems to be improved and there might be a short term HRQL benefit. In people with persistent hypercapnia after a COPD exacerbation, chronic NIV might prolong admission-free survival without a beneficial effect on HRQL. In stable COPD, future RCTs comparing NIV to a control group receiving standard care might no longer be warranted, but research should focus on identifying participant characteristics that would define treatment success. Furthermore, the optimal timing for initiation of NIV after a severe COPD exacerbation is still unknown.

Defining successful non-invasive ventilation initiation: Data from a real-life cohort

BACKGROUND AND OBJECTIVE

When home non-invasive ventilation (NIV) is initiated, five goals need to be achieved: a daily use >4 h/day, an improvement in gas exchange, health-related quality of life (HRQL) and sleep quality without side effects. Our aim was to assess how frequently these five goals were reached and the factors predictive of achievement.

METHODS

We conducted a monocentric cohort study that included patients electively established on home NIV over 2 years. HRQL was assessed at baseline and follow-up by the Severe Respiratory Insufficiency questionnaire. Adequate initiation was defined as the achievement of at least three of five goals and successful initiation as the achievement of all.

RESULTS

Two-hundred and fifty patients were included at baseline. NIV was initiated for: obesity hypoventilation syndrome (n = 95; 38%), neuromuscular disease (n = 70; 28%), chronic obstructive pulmonary disease (n = 66; 26%) and chest wall disease (n = 19; 8%). At follow-up, measures of all five goals were available in 141 (56%) patients. NIV initiation was adequate for 96 (68%) patients and successful for 12 (9%) patients. In multivariate analysis, a tidal volume ≥ 7.8 ml/kg of ideal body weight was associated with an increased likelihood of adequate NIV initiation (hazard ratio: 5.765 [95% CI:1.824-18.223], p = 0.006]. Improvement in daytime partial arterial carbon dioxide pressure (PaCO₂ ) was not correlated to improvement in HRQL or sleep quality. Severe to very severe NIV-related side effects occurred in 114 (47%) patients and were associated with higher daytime PaCO₂ (6.35 ± 1.08 vs. 5.92 ± 0.79 kPa, p < 0.001).

CONCLUSION

Successful home NIV initiation is rarely achieved in real life. HRQL and NIV tolerance should be assessed to improve patient-centred outcomes.

Impact of Confinement in Patients under Long-Term Noninvasive Ventilation during the First Wave of the SARS-CoV-2 Pandemic: A Remarkable Resilience

Background

During the first wave of the SARS-CoV-2 pandemic in Switzerland, confinement was imposed to limit transmission and protect vulnerable persons. These measures may have had a negative impact on perceived quality of care and symptoms in patients with chronic disorders.

Objectives

To determine whether patients under long-term home noninvasive ventilation (LTHNIV) for chronic respiratory failure (CRF) were negatively affected by the 56-day confinement (March–April 2020).

Methods

A questionnaire-based survey exploring mood disturbances (HAD), symptom scores related to NIV (S³-NIV), and perception of health-care providers during confinement was sent to all patients under LTHNIV followed up by our center. Symptom scores and data obtained by ventilator software were compared between confinement and the 56 days prior to confinement.

Results

Of a total of 100 eligible patients, 66 were included (median age: 66 years [IQR: 53–74]): 35 (53%) with restrictive lung disorders, 20 (30%) with OHS or SRBD, and 11 (17%) with COPD or overlap syndrome. Prevalence of anxiety (n = 7; 11%) and depressive (n = 2; 3%) disorders was remarkably low. Symptom scores were slightly higher during confinement although this difference was not clinically relevant. Technical data regarding ventilation, including compliance, did not change. Patients complained of isolation and lack of social contact. They felt supported by their relatives and caregivers but complained of the lack of regular contact and information by health-care professionals.

Conclusions

Patients under LTHNIV for CRF showed a remarkable resilience during the SARS-CoV-2 confinement period. Comments provided may be helpful for managing similar future health-care crises.

The Severe Respiratory Insufficiency Application (SRI App): a pilot randomised controlled trial

An application (app) for the Severe Respiratory Insufficiency Questionnaire (SRI) has been designed and developed for mobile devices. In a randomised controlled trial comprising 60 patients with chronic respiratory failure, the app was compared with the classic paper SRI. Thereby, it was shown that the SRI app is a practical tool that is well accepted. Missing values can be completely avoided by using the SRI app. Finally, reliability, convergent and discriminant validities were established. Accordingly, for the individual SRI subscales, Cronbach's alpha ranged between 0.56 and 0.81 (app) and between 0.54 and 0.83 (paper), respectively. The multilingual SRI app is accessible free of charge for non-profit research purposes.

Long-term noninvasive ventilation in COPD: current evidence and future directions

Introduction: Long-term noninvasive ventilation (NIV) is an established treatment for end-stage COPD patients suffering from chronic hypercapnic respiratory failure. This is reflected by its prominent position in national and international medical guidelines. Areas covered: In recent years, novel developments in technology such as auto-titrating machines and hybrid modes have emerged, and when combined with advances in information and communication technologies, these developments have served to improve the level of NIV-based care. Such progress has largely been instigated by the fact that healthcare systems are now confronted with an increase in the number of patients, which has led to the need for a change in current infrastructures. This article discusses the current practices and recent trends, and offers a glimpse into the future possibilities and requirements associated with this form of ventilation therapy. Expert opinion: Noninvasive ventilation is an established and increasingly used treatment option for patients with chronic hypercapnic COPD and those with persistent hypercapnia following acute hypercapnic lung failure. The main target is to augment alveolar hypoventilation by reducing P_aCO₂ to relieve symptoms. Nevertheless, when dealing with severely impaired patients, it appears necessary to switch the focus to patient-related outcomes such as health-related quality of life.

Home mechanical ventilation: quality of life patterns after six months of treatment

Background

It has been shown that home mechanical ventilation improves quality of life, but it has not been widely studied which particular patient groups benefit the most from starting this type of therapy. The purpose of this prospective observational study was to evaluate quality of life change patterns 6 months after initiation of home mechanical ventilation in patients suffering from chronic respiratory failure using patient reported outcomes.

Methods

We enrolled 74 chronic respiratory failure patients starting invasive or noninvasive home mechanical ventilation through the Semmelweis University Home Mechanical Ventilation Program. Quality of life was evaluated at baseline and at 6 months after initiation of home mechanical ventilation using the Severe Respiratory Insufficiency Questionnaire.

Results

Overall quality of life showed 10.5% improvement 6 months after initiation of home mechanical ventilation (p < 0.001). The greatest improvement was observed in Respiratory complaint (20.4%, p = 0.015), Sleep and attendant symptoms (19.3%, p < 0.001), and Anxiety related subscales (14.4%, p < 0.001). Interface (invasive versus noninvasive ventilation) was not associated with improvement in quality of life (p = 0.660). Severely impaired patients showed the greatest improvement (CC = -0.328, p < 0.001). Initial diagnosis contributed to the observed change (p = 0.025), with chronic obstructive pulmonary disease and obesity hypoventilation syndrome patients showing the greatest improvement, while amyotrophic lateral sclerosis patients showed no improvement in quality of life. We found that patients who were started on long term ventilation in an acute setting, required oxygen supplementation and had low baseline quality of life, showed the most improvement during the six-month study period.

Conclusions

Our study highlights the profound effect of home mechanical ventilation on quality of life in chronic respiratory failure patients that is indifferent of ventilation interface but is dependent on initial diagnosis and some baseline characteristics, like acute initiation, oxygen supplementation need and baseline quality of life.

Trial registration

This study was approved by and registered at the ethics committee of Semmelweis University (SE TUKEB 251/2017; 20th of December, 2017).

Determinants of Clinical COPD Questionnaire in Patients with COPD: A Cross-Sectional Observational Study

BACKGROUND

The Clinical COPD Questionnaire (CCQ) has been suggested by the Global Initiative of Chronic Obstructive Lung Disease (GOLD) as a comprehensive symptom measurement tool, which helps to classify patients in order to direct pharmacological treatment. Therefore, it is essential to understand its determinants.

OBJECTIVES

To identify the determinants of the overall CCQ score and scores of its 3 subdomains among chronic obstructive pulmonary disease (COPD) patients from China.

METHODS

A total of 1,241 COPD patients in the outpatient department of the Second Xiangya Hospital in China were recruited. Basic information and clinical data were collected. Differences in the GOLD categories based on Modified Medical Research Council Dyspnea Scale (mMRC), COPD Assessment Test (CAT), and CCQ were compared. Multiple linear regression analyses were performed to evaluate determinant factors of the total CCQ and subdomain scores.

RESULTS

The total CCQ and/or separate domain scores significantly differed with sex, age, BMI, smoking status, biomass fuel exposure, exacerbation frequency, mMRC, CAT, and GOLD grades and groups. Subjects with asthma-COPD overlap (ACO) had worse health status based on CCQ than those with COPD alone. As for the 16 subgroups based on GOLD 2017, statistical differences in the total CCQ and functional domain scores were found among subgroups 1A-4A, 1B-4B, and 1D-4D. The mMRC classified much more patients into more symptom groups than CAT and CCQ. No significant difference was observed in the GOLD categories between the CAT and CCQ (cut point = 1.5). Multiple linear regression analysis showed that smoking status, underweight, ACO, post-bronchodilator FEV1% predicted <50%, exacerbation history, and mMRC were independently associated with the total CCQ score. Only 3 variables were significantly associated with the symptom domain: ACO, exacerbations, and mMRC; for the functional domain, age ≥75 years, ACO, post-bronchodilator FEV1% predicted <50%, exacerbation history, and mMRC were significant; female sex, underweight, frequent exacerbations (≥2), and mMRC were significantly associated with higher scores in the mental domain.

CONCLUSIONS

The classification of COPD produced by mMRC, CAT, and CCQ was not identical. Smoking status, underweight, ACO, post-bronchodilator FEV1% predicted <50%, exacerbation history, and mMRC were associated with lower health-related quality of life assessed by the total CCQ score, while different subdomains of CCQ had different determinant factors.

Validation of the Hungarian version of the SRI Questionnaire

BACKGROUND

Home mechanical ventilation is a reliable treatment for patients suffering from chronic respiratory failure, improving survival and quality of life. Prevalence has been increasing worldwide as a result of evolving technical possibilities, telemedicine and improving national guidelines. Projects to establish a national guideline and registry for patients treated with home mechanical ventilation are currently under way in Hungary and our aim was to validate a quality of life questionnaire suited for evaluation and follow up in this specific patient group. The Severe Respiratory Insufficiency Questionnaire (SRI) is a quality of life tool designed to evaluate patients receiving home mechanical ventilation and has been validated both in patient groups receiving invasive and noninvasive ventilation.

METHODS

The Hungarian version of the SRI was created using the translation-backtranslation method, which was then tested for validity, viability and reliability in a cohort involving patients from three centers, receiving long-term home mechanical ventilation for chronic respiratory failure through an invasive or noninvasive interface. Patient data was collected (demographic data, lung function test, arterial blood gas, ventilation settings) and quality of life was measured with the previously validated SF-36 and newly created Hungarian SRI Questionnaires at two time points.

RESULTS

One hundred four patients receiving home mechanical ventilation were enrolled. The time to complete the SRI Questionnaire was 8.6 (±3.1) minutes, 69.2% questionnaires were self-administered. Exploratory factor analysis explained 73.8% of the variance of the questionnaire, but resulted in 13 scales. We found correlations between the SRI subscale scores to corresponding scales of the previously validated general quality of life survey SF-36. The Cronbach alpha coefficient was 0.928 for the Summary Scale of the SRI Questionnaire, proving high internal consistency. Reproducibility was high for most scales, resulting in a high overall correlation for the summary score (0.877, p < 0.001).

CONCLUSIONS

The Hungarian version of the SRI Questionnaire is a viable, valid, reliable and reproduceable quality of life tool applicable for patients treated with home mechanical ventilation.

Validation of the Finnish severe respiratory insufficiency questionnaire

INTRODUCTION

Chronic respiratory insufficiency impacts patients' lives and reduces quality of life. The Severe Respiratory Insufficiency (SRI) questionnaire examines health-related quality of life and is designed specifically for patients receiving home mechanical ventilation (HMV) for chronic respiratory failure (CRF).

OBJECTIVES

The aim of this study was to validate the Finnish version of the SRI and study its reproducibility in patients with CRF.

METHODS

Our 74 patients receiving HMV or long-term oxygen treatment for CRF or both completed the SRI and St George's Respiratory questionnaires (SGRQ) three times (at baseline, and then one week and one month later). Reliability and validity of the questionnaires was analysed with Cronbach's alpha and intraclass correlation coefficient. Patients were prospectively followed up for 5 years, with data collected on their use of hospital services and mortality.

RESULTS

Cronbach's alpha in the SRI ranged from 0.67 to 0.88 and was >0.7 on all subscales except the "attendant symptoms and sleep". On four subscales, Cronbach's alpha was >0.8, and on the summary scale, 0.95. The SRI showed high correlation with SGRQ. Both tests showed good reproducibility. During the 5-year follow-up, 27 (36%) patients died.

CONCLUSIONS

The Finnish SRI proved valid, reliable and reproducible. Its psychometric properties were good and similar to those of the original questionnaire and of other validation studies.

Respiratory Failure, Noninvasive Ventilation, and Symptom Burden: An Observational Study

BACKGROUND

Noninvasive ventilation (NIV) is commonly used to manage acute respiratory failure due to decompensated cardiorespiratory disease. We describe symptom burden in this population.

MEASURES

Fifty consecutive, consenting, English-speaking, cognitively intact patients, admitted to wards other than the intensive care unit in a tertiary teaching hospital and treated with NIV for hypercapnic respiratory failure, were recruited. The 14-item Condensed Memorial Symptom Assessment Scale was used to assess physical and psychological symptoms within 36 hours of commencing NIV. Breathlessness (using Borg score), pain location and intensity using a numerical rating scale, and four symptoms potentially prevalent in patients undergoing NIV (cough, sputum, gastric bloating, and dry eyes) were also assessed.

OUTCOMES

Patients reported a median of 10 symptoms (IQR 9-13). A median of five symptoms (IQR 3-7) were rated as severe. Breathlessness was the most prevalent and most distressing symptom, with participants reporting a mean maximum Borg score of 7.55 over the 24 hours before admission. Dry mouth, lack of energy, cough, sputum, difficulty sleeping, and psychological symptoms were prevalent. Pain, when reported, was of moderate intensity and contributed to distress.

CONCLUSIONS/LESSONS LEARNED

This study describes the patient-reported symptoms occurring during an episode of acute respiratory failure. Understanding the symptom profile of patients in this setting may allow clinicians to target symptom relief while simultaneously managing respiratory failure, enhancing care.

Health-related quality of life as predictor for mortality in patients treated with long-term mechanical ventilation

Background

The Severe Respiratory Insufficiency (SRI) questionnaire is a specific measure of health-related quality of life (HRQoL) in patients treated with long-term mechanical ventilation (LTMV). The aim of the present study was to examine whether SRI sum scores and related subscales are associated with mortality in LTMV patients.

Methods

The study included 112 LTMV patients (non-invasive and invasive) from the Norwegian LTMV registry in Western Norway from 2008 with follow-up in August 2014. SRI data were obtained through a postal questionnaire, whereas mortality data were obtained from the Norwegian Cause of Death Registry. The SRI questionnaire contains 49 items and seven subscales added into a summary score (range 0–100) with higher scores indicating a better HRQoL. The association between the SRI score and mortality was estimated as hazard ratios (HRs) with 95% confidence intervals (95% CI) using Cox regression models and HRs were estimated per one unit change in the SRI score.

Results

Of the 112 participating patients in 2008, 52 (46%) had died by August 2014. The mortality rate was the highest in patients with chronic obstructive pulmonary disease (75%), followed by patients with neuromuscular disease (46%), obesity hypoventilation syndrome (31%) and chest wall disease (25%) (p < 0.001). Higher SRI sum scores in 2008 were associated with a lower mortality risk after adjustment for age, education, hours a day on LTMV, time since initiation of LTMV, disease category and comorbidity (HR 0.98, 95% CI: 0.96–0.99). In addition, SRI-Physical Functioning (HR 0.98, 95% CI: 0.96–0.99), SRI-Psychological Well-Being (HR 0.98, 95% CI: 0.97–0.99), and SRI-Social Functioning (HR 0.98, 95% CI: 0.97–0.99) remained significant risk factors for mortality after covariate adjustment. In the subgroup analyses of patient with neuromuscular diseases we found significant inverse associations between some of the SRI subscales and mortality.

Conclusions

SRI score is associated with mortality in LTMV-treated patients. We propose the use of SRI in the daily clinic with repeated measurements as part of individual follow-up. Randomized clinical trials with interventions aimed to improve HRQoL in LTMV patients should consider the SRI questionnaire as the standard HRQoL measurement.

Electronic supplementary material

The online version of this article (10.1186/s12890-018-0768-4) contains supplementary material, which is available to authorized users.

Improvement in hypercapnia does not predict survival in COPD patients on chronic noninvasive ventilation

Purpose

It has recently been shown that chronic noninvasive ventilation (NIV) improves a number of outcomes including survival, in patients with stable hypercapnic COPD. However, the mechanisms responsible for these improved outcomes are still unknown. The aim of the present study was to identify parameters associated with: 1) an improved arterial partial pressure of carbon dioxide (PaCO₂) and 2) survival, in a cohort of hypercapnic COPD patients treated with chronic NIV.

Patients and methods

Data from 240 COPD patients treated with chronic NIV were analyzed. Predictors for the change in PaCO₂ and survival were investigated using multivariate linear and Cox regression models, respectively.

Results

A higher level of bicarbonate before NIV initiation, the use of higher inspiratory ventilator pressures, the presence of anxiety symptoms, and NIV initiated following an exacerbation compared to NIV initiated in stable disease were associated with a larger reduction in PaCO₂. A higher body mass index, a higher FEV₁, a lower bicarbonate before NIV initiation, and younger age and NIV initiation in stable condition were independently associated with better survival. The change in PaCO₂ was not associated with survival, neither in a subgroup of patients with a PaCO₂ >7.0 kPa before the initiation of NIV.

Conclusion

Patients with anxiety symptoms and a high bicarbonate level at NIV initiation are potentially good responders in terms of an improvement in hypercapnia. Also, higher inspiratory ventilator pressures are associated with a larger reduction in PaCO₂. However, the improvement in hypercapnia does not seem to be associated with an improved survival and emphasizes the need to look beyond PaCO₂ when considering NIV initiation.

Chinese version of the severe respiratory insufficiency questionnaire for patients with COPD receiving long-term oxygen therapy

Purpose

Patients with advanced-stage COPD often experience severe hypoxemia. Treatment with long-term oxygen therapy (LTOT) may relieve patients' symptoms and increase survival. As COPD is incurable, improving patients' health-related quality of life is important. The Chinese version of the Severe Respiratory Insufficiency Questionnaire (SRI) is valid for patients with hypercapnic COPD undergoing noninvasive positive airway pressure ventilation at home. However, the reliability and validity of the Chinese SRI for patients with COPD undergoing LTOT have not been investigated.

Patients and methods

We analyzed reliability using Cronbach's α coefficient. Construct validity was assessed with principal, exploratory, and confirmatory factor analysis. Concurrent validity was evaluated through the correlation between SRI domains and Chronic Respiratory Disease Questionnaire (CRQ) domains. Content validity was assessed by calculating the correlation between each SRI item score and the total score for the relevant domain.

Results

In total, 161 patients participated in this study. The Cronbach's α coefficient for all SRI domains was >0.7, except for the attendant symptoms and sleep domain. Exploratory and confirmatory factor analysis showed a good model fit for each domain, but the factors extracted from each domain were correlated. SRI and CRQ domains correlated well with respect to similar aspects of health-related quality of life, indicating good concurrent validity. Content validity was indirectly shown by a good correlation between each item score and the total score of the relevant domain.

Conclusion

The Chinese version of the SRI has a good reliability and validity for patients with COPD undergoing LTOT in China.

Health-related quality of life measurement in patients with chronic respiratory failure

The improvement of health-related quality of life (HRQL) is an important goal in managing patients with chronic respiratory failure (CRF) receiving long-term oxygen therapy (LTOT) and/or domiciliary noninvasive ventilation (NIV). Two condition-specific HRQL questionnaires have been developed to specifically assess these patients: the Maugeri Respiratory Failure Questionnaire (MRF) and the Severe Respiratory Insufficiency Questionnaire (SRI). The MRF is more advantageous in its ease of completion; conversely, the SRI measures diversified health impairments more multi-dimensionally and discriminatively with greater balance, especially in patients receiving NIV. The SRI is available in many different languages as a result of back-translation and validation processes, and is widely validated for various disorders such as chronic obstructive pulmonary disease, restrictive thoracic disorders, neuromuscular disorders, and obesity hypoventilation syndrome, among others. Dyspnea and psychological status were the main determinants for both questionnaires, while the MRF tended to place more emphasis on activity limitations than SRI. In comparison to existing generic questionnaires such as the Medical Outcomes Study 36-item short form (SF-36) and disease-specific questionnaires such as the St. George's Respiratory Questionnaire (SGRQ) and the Chronic Respiratory Disease Questionnaire (CRQ), both the MRF and the SRI have been shown to be valid and reliable, and have better discriminatory, evaluative, and predictive features than other questionnaires. Thus, in assessing the HRQL of patients with CRF using LTOT and/or NIV, we might consider avoiding the use of the SF-36 or even the SGRQ or CRQ alone and consider using the CRF-specific SRI and MRF in addition to existing generic and/or disease-specific questionnaires.

Evaluating the Clinical COPD Questionnaire: A systematic review

The Clinical COPD Questionnaire (CCQ) is recommended by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) to evaluate health status in patients with COPD. The objective of this work was to systemically assess the reliability, validity, responsiveness and minimum clinically important difference (MCID) of the CCQ. A structured search was conducted in three databases to identify articles that evaluated the psychometric properties of the CCQ in individuals with COPD. Two investigators screened the title, abstract and full text of the articles to determine study eligibility and performed the data extraction. Quality assessment of included studies was assessed by the COSMIN (Consensus-Based Standards for the Selection of Health Measurement Instruments) checklist. Finally, 43 studies were included, over half of which had fair methodological quality. Internal consistency (reliability) of the CCQ total score ranged from 0.84 to 0.94, and test-retest reliability was 0.70-0.99. The overall CCQ had a better correlation with St George's Respiratory Questionnaire (SGRQ; from 0.71 to 0.88) and COPD Assessment Test (CAT; from 0.64 to 0.88) than modified Medical Research Council (mMRC; from 0.392 to 0.668) and forced expiratory volume in 1 s (FEV₁ % predicted; from -0.31 to -0.68). Scores were different within GOLD stages, groups, composite events and co-morbidities. CCQ was sensitive to exacerbations, pulmonary rehabilitation and smoking cessation with the MCID of 0.4. The CCQ is a very useful and practical tool that can be used in clinical populations with good reliability, validity and responsiveness to interventions.

Factors associated with change in health-related quality of life among individuals treated with long-term mechanical ventilation, a 6-year follow-up study

AIMS

To examine changes and explanatory variables for changes in health-related quality of life in patients treated with long-term mechanical ventilation over a 6-year period.

BACKGROUND

Long-term mechanical ventilation is a treatment for individuals with chronic hypercapnic respiratory failure, primarily caused by neuromuscular diseases, obesity hypoventilation syndrome, chronic obstructive pulmonary and restrictive thoracic diseases. Studies on long-term outcome on health-related quality of life and factors influencing it are lacking.

DESIGN

Prospective cohort study.

METHODS

Data were collected from the Norwegian Long-Term-Mechanical-Ventilation Registry and from patient-reported questionnaire in 2008 and 2014. Health-related quality of life was measured by the Severe Respiratory Insufficiency questionnaire, containing 49 items and seven subdomains. Linear mixed effects models were used to measure changes and identify factors for changes.

RESULTS

After 6 years, 60 patients were still participating, out of 127 at baseline. Health-related quality of life improved significantly in the total score and in four subdomains of the questionnaire. Satisfaction with training in long-term mechanical ventilation was an explanatory variable for improved 'psychological well-being' and follow-up for improvement of 'anxiety'. Side effects of the treatment like facial soreness were associated with the total score. High age and high forced vital capacity were related to lower 'physical function' and improved 'social functioning', respectively.

CONCLUSION

Long-term mechanical ventilation over 6 years improved health-related quality of life in most patients. Patient training, follow-up and reduction of side effects, largely delivered by trained nurses, contribute to achieve the main goal of the treatment-improved health-related quality of life.

The Chinese version of the Severe Respiratory Insufficiency questionnaire for patients with chronic hypercapnic chronic obstructive pulmonary disease receiving non-invasive positive pressure ventilation

OBJECTIVES

The Severe Respiratory Insufficiency (SRI) questionnaire is the best assessment tool for health-related quality of life in patients with chronic obstructive pulmonary disease (COPD) receiving non-invasive positive pressure ventilation (NIPPV). This study aimed to translate the SRI Questionnaire into Chinese and to validate it.

DESIGN

Prospective validation study.

SETTING AND PARTICIPANTS

A total of 149 participants with chronic hypercapnic COPD receiving NIPPV completed the study.

METHODS

The SRI questionnaire was translated into Chinese using translation and back-translation. Reliability was gauged using Cronbach's α coefficient. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used to assess construct validity. Content validity was confirmed by evaluating the relationship between the score of each item and the total score of the relevant subscale.

RESULTS

Cronbach's α coefficients for each subscale and summary scale were above 0.7. Using EFA, one factor was extracted from the anxiety and summary scales and two factors were extracted from the remaining six subscales. Based on the EFA results, subsequent CFA revealed a good model fit for each subscale, but the extracted factors of each subscale were correlated. Content validity was confirmed by the good relationship between the score of each item and the total score of the relevant subscale.

CONCLUSION

The Chinese version of the SRI questionnaire is valid and reliable for patients with chronic hypercapnic COPD receiving NIPPV in China.

TRIAL REGISTRATION NUMBER

NCT02499718.

The frequent and underrecognised co-occurrence of acute exacerbated COPD and depression warrants screening: a systematic review

Patients with acute exacerbated chronic obstructive pulmonary disease (AECOPD) and concurrent depression suffer significant psychological stress and decreased quality of life. The aim of this study was to collate data, guidelines and recommendations from publications on the screening and management of depressive mood disorders in patients hospitalised with AECOPD.We systematically searched four databases for publications reporting screening or management of depression in patients hospitalised for AECOPD. The identification of articles was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.Out of 1494 original articles screened, 35 met all inclusion criteria. These report a prevalence of depression in AECOPD ranging between 9.5% and 85.6%. Some studies report high postadmission mortality rates for depressive AECOPD patients, and higher readmission rates in depressive versus nondepressive AECOPD patients. Importantly, none of the 35 publications included suggestions on the screening and management of depression in AECOPD.Depression and AECOPD frequently co-occur, and this worsens outcomes. Yet we did not find recommendations on management, and few interventional studies. Patients hospitalised with AECOPD should be systematically screened for depression and treatment recommendations should be developed for these patients. Randomised studies on how to screen and treat depression in hospitalised AECOPD are necessary.

Comparison of Different Disease-Specific Health-Related Quality of Life Measurements in Patients with Long-Term Noninvasive Ventilation

BACKGROUND

Two disease-specific questionnaires have been developed to assess health-related quality of life (HRQL) in patients with chronic respiratory failure: the Severe Respiratory Insufficiency (SRI) Questionnaire and the Maugeri Respiratory Failure (MRF) Questionnaire. We aimed to compare the characteristics of the SRI, MRF-26, and St. George's Respiratory Questionnaire (SGRQ) for use in patients with home noninvasive ventilation (NIV).

METHODS

Fifty-six outpatients receiving long-term NIV were recruited and underwent assessments of pulmonary function, arterial blood gas, HRQL, dyspnea, and psychological status.

RESULTS

Correlations of the SRI and MRF-26 with the SGRQ were modest. While pulmonary function was weakly related to only some domains of the SRI and MRF-26, the modified Medical Research Council (mMRC) dyspnea scale and Hospital Anxiety and Depression Scale (HADS) were significantly related to all domains of the SRI and MRF-26. Multiple regression analyses showed that HADS depression and mMRC accounted for 34% and 27% of the variance in the SRI, 24% and 37% in the MRF-26, and 17% and 46% in the SGRQ, respectively.

CONCLUSIONS

The SRI and MRF-26 were reliable questionnaires for patients receiving long-term NIV. Dyspnea and psychological status were their main common determinants. The SRI covers more psychological health impairments than the MRF. This trial is registered with ClinicalTrials.gov Identifier: NCT00905476.

Validation of the Portuguese Severe Respiratory Insufficiency Questionnaire for home mechanically ventilated patients

The aim of this study was to develop and validate the professional translation and cultural adaptation of the Portuguese Severe Respiratory Insufficiency (SRI) Questionnaire. The sample was composed of 93 patients (50 male patients, 53.8%) with a mean age of 66.3 years. The most frequent diagnostic groups were chronic obstructive pulmonary disease, obesity hypoventilation syndrome and restrictive chest wall disorders. The patients were asked to fill in both the SRI and SF-36 questionnaires. Factor analysis of the SRI questionnaire was performed leading to an explained variance of 73%, and resulted in 13 components. When analyzing the reliability, we obtained values for Cronbach's alpha above 0.70 for most subscales with the reliability of the summary scale being even higher (0.84). This professional translation and cultural adaptation of the Portuguese SRI Questionnaire has good psychometric properties which are similar, not only to the original, but also to other translations. These characteristics make this questionnaire applicable to the Portuguese population receiving home mechanical ventilation for severe respiratory insufficiency.

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.

Nocturnal non-invasive ventilation in COPD patients with prolonged hypercapnia after ventilatory support for acute respiratory failure: a randomised, controlled, parallel-group study

INTRODUCTION

The effectiveness of non-invasive positive pressure ventilation (NIV) in COPD patients with prolonged hypercapnia after ventilatory support for acute respiratory failure (ARF) remains unclear. We investigated if nocturnal NIV in these patients prolongs the time to readmission for respiratory causes or death (primary endpoint) in the following 12 months.

METHODS

201 COPD patients admitted to hospital with ARF and prolonged hypercapnia >48 h after termination of ventilatory support were randomised to NIV or standard treatment. Secondary outcomes were daytime arterial blood gasses, transcutaneous PCO2 during the night, lung function, health-related quality-of-life (HRQL), mood state, daily activities and dyspnoea.

RESULTS

1 year after discharge, 65% versus 64% of patients (NIV vs standard treatment) were readmitted to hospital for respiratory causes or had died; time to event was not different (p=0.85). Daytime PaCO2 was significantly improved in NIV versus standard treatment (PaCO2 0.5 kPa (95% CI 0.04 to 0.90, p=0.03)) as was transcutaneous PCO2 during the night. HRQL showed a trend (p=0.054, Severe Respiratory Insufficiency questionnaire) in favour of NIV. Number of exacerbations, lung function, mood state, daily activity levels or dyspnoea was not significantly different.

DISCUSSIONS

We could not demonstrate an improvement in time to readmission or death by adding NIV for 1 year in patients with prolonged hypercapnia after an episode of NIV for ARF. There is no reason to believe the NIV was not effective since daytime PaCO2 and night-time PCO2 improved. The trend for improvement in HRQL favouring NIV we believe nevertheless should be explored further.

TRIAL REGISTRATION NUMBER

NTR1100.

Nocturnal noninvasive positive pressure ventilation in stable COPD: a systematic review and individual patient data meta-analysis

INTRODUCTION

The effects of nocturnal noninvasive positive pressure ventilation (NIPPV) in patients with stable chronic obstructive pulmonary disease (COPD) remain controversial.

METHODS

The Cochrane Airways group Register of Trials, MEDLINE, EMBASE and CINAHL were searched up to August 2012. Individual patient data from randomised controlled trials on NIPPV outcomes were selected for two separate meta-analyses: the first with follow-up of 3 months and the second with 12 months of follow-up. Additionally, subgroup analyses within the NIPPV group comparing IPAP levels, compliance and levels of hypercapnia on change in PaCO2 after 3 months were performed.

RESULTS

Seven trials (245 patients) were included. All studies were considered of moderate to high quality. No significant difference was found between NIPPV and control groups after 3 or 12 months of follow-up when looking at PaCO2 and PaO2, 6-minute walking distance, health-related quality-of-life, forced expiratory volume in 1 s, forced vital capacity, maximal inspiratory pressure and sleep efficiency. Significant differences in change in PaCO2 after 3 months were found for patients ventilated with IPAP levels of at least 18 cm H2O, for patients who used NIPPV for at least 5 h per night as well as for patients with baseline PaCO2 of at least 55 mm Hg when compared to patients with lower IPAP levels, poorer compliance or lower levels of hypercapnia.

DISCUSSION

At present, there is insufficient evidence to support the application of routine NIPPV in patients with stable COPD. However, higher IPAP levels, better compliance and higher baseline PaCO2 seem to improve PaCO2.