Outcome of COPD patients performing nocturnal non-invasive mechanical ventilation

Supplemental oxygen and noninvasive ventilation

The respiratory system attempts to maintain normal levels of oxygen and carbon dioxide. However, airflow limitation, parenchymal abnormalities and dysfunction of the respiratory pump may be compromised in individuals with advanced COPD, eventually leading to respiratory failure, with reduced arterial oxygen tension (hypoxaemia) and/or increased arterial carbon dioxide tension (P aCO2 ; hypercapnia). Hypoxaemia may persist in individuals with severe COPD despite smoking cessation and optimisation of pharmacotherapy. Long-term oxygen therapy (LTOT) can improve survival in those with severe daytime hypoxaemia, whereas those with less severe hypoxaemia may only have improved exercise capacity and dyspnoea. Changes in respiratory physiology that occur during sleep further predispose to hypoxaemia, particularly in individuals with COPD. However, the major cause of hypoxaemia is hypoventilation. Noninvasive ventilation (NIV) may reduce mortality and need for intubation in individuals with COPD and acute hypercapnic respiratory failure. However, NIV may also improve survival and quality of life in individuals with stable, chronic hypercapnia and is now suggested for those with prolonged hypercapnia (e.g. P aCO2 >55 mmHg 2-6 weeks after hospital discharge) when clinically stable and after optimisation of medical therapy including LTOT if indicated. Many questions remain about the optimal mode, settings and goal of NIV therapy.

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.

Nocturnal non invasive ventilation in normocapnic cystic fibrosis patients: a pilot study

BACKGROUND AND AIM

In patients with cystic fibrosis (CF) non-invasive ventilation (NIV) improves lung mechanics and gas exchange, and decreases the work of breathing. Domiciliary NIV is mainly used in hypercapnic patients with severe disease, because it counteracts the progression of lung functional impairment and it is often used as a useful "bridge" to lung transplantation. However, to date, there are no standardized criteria to indicate the effect of a precocious starting of NIV in patients with functional ventilation inhomogeneity without hypercapnia. In this pilot study we assessed whether an early NIV treatment might influence functional and clinical outcomes in CF patients.

METHODS

Six normocapnic CF patients were treated for one year with NIV. At baseline and after 1 year of NIV treatment, arterial gas analysis, spirometry, MBW to derive LCI, nocturnal cardio-respiratory polygraphy (PG), and Pittsburgh Sleep Quality Index (PSQI) were perfomed in all enrolled patients.

RESULTS

After one year, despite spirometric and LCI values remain statistically not modified, the number of infectious exacerbations was reduced by 50%.

CONCLUSIONS

These results suggest that nocturnal NIV improves clinical conditions of stable CF patients. Finally, we suggest that this procedure can be useful to counteract the progression of lung disease even in normocapnic patients.

Patient's treatment burden related to care coordination in the field of respiratory diseases

The management of respiratory diseases requires various levels of care: multidisciplinary teams, educational and behavioural interventions, self-management and home-based technical support are vital to ensure adequate care management. However, it is often difficult to access these networks due to fragmentation of patient care and treatment burden. Care coordination aims to ensure patients have a central role and that there is continuity of care among various levels and professionals involved. Moreover, the coronavirus disease pandemic has caused strain on the global healthcare system, with care coordination becoming increasingly important in increasing the resilience of health systems, supporting healthcare professionals and ensuring the right treatment and adequate level of care for these patients.

Association of Home Noninvasive Positive Pressure Ventilation With Clinical Outcomes in Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-analysis

IMPORTANCE

The association of home noninvasive positive pressure ventilation (NIPPV) with outcomes in chronic obstructive pulmonary disease (COPD) and hypercapnia is uncertain.

OBJECTIVE

To evaluate the association of home NIPPV via bilevel positive airway pressure (BPAP) devices and noninvasive home mechanical ventilator (HMV) devices with clinical outcomes and adverse events in patients with COPD and hypercapnia.

DATA SOURCES

Search of MEDLINE, EMBASE, SCOPUS, Cochrane Central Registrar of Controlled Trials, Cochrane Database of Systematic Reviews, National Guideline Clearinghouse, and Scopus for English-language articles published from January 1, 1995, to November 6, 2019.

STUDY SELECTION

Randomized clinical trials (RCTs) and comparative observational studies that enrolled adults with COPD with hypercapnia who used home NIPPV for more than 1 month were included.

DATA EXTRACTION AND SYNTHESIS

Data extraction was completed by independent pairs of reviewers. Risk of bias was evaluated using the Cochrane Collaboration risk of bias tool for RCTs and select items from the Newcastle-Ottawa Scale for nonrandomized studies.

MAIN OUTCOMES AND MEASURES

Primary outcomes were mortality, all-cause hospital admissions, need for intubation, and quality of life at the longest follow-up.

RESULTS

A total of 21 RCTs and 12 observational studies evaluating 51 085 patients (mean [SD] age, 65.7 [2.1] years; 43% women) were included, among whom there were 434 deaths and 27 patients who underwent intubation. BPAP compared with no device was significantly associated with lower risk of mortality (22.31% vs 28.57%; risk difference [RD], -5.53% [95% CI, -10.29% to -0.76%]; odds ratio [OR], 0.66 [95% CI, 0.51-0.87]; P = .003; 13 studies; 1423 patients; strength of evidence [SOE], moderate), fewer patients with all-cause hospital admissions (39.74% vs 75.00%; RD, -35.26% [95% CI, -49.39% to -21.12%]; OR, 0.22 [95% CI, 0.11-0.43]; P < .001; 1 study; 166 patients; SOE, low), and lower need for intubation (5.34% vs 14.71%; RD, -8.02% [95% CI, -14.77% to -1.28%]; OR, 0.34 [95% CI, 0.14-0.83]; P = .02; 3 studies; 267 patients; SOE, moderate). There was no significant difference in the total number of all-cause hospital admissions (rate ratio, 0.91 [95% CI, 0.71-1.17]; P = .47; 5 studies; 326 patients; SOE, low) or quality of life (standardized mean difference, 0.16 [95% CI, -0.06 to 0.39]; P = .15; 9 studies; 833 patients; SOE, insufficient). Noninvasive HMV use compared with no device was significantly associated with fewer all-cause hospital admissions (rate ratio, 0.50 [95% CI, 0.35-0.71]; P < .001; 1 study; 93 patients; SOE, low), but not mortality (21.84% vs 34.09%; RD, -11.99% [95% CI, -24.77% to 0.79%]; OR, 0.56 [95% CI, 0.29-1.08]; P = .49; 2 studies; 175 patients; SOE, insufficient). There was no statistically significant difference in the total number of adverse events in patients using NIPPV compared with no device (0.18 vs 0.17 per patient; P = .84; 6 studies; 414 patients).

CONCLUSIONS AND RELEVANCE

In this meta-analysis of patients with COPD and hypercapnia, home BPAP, compared with no device, was associated with lower risk of mortality, all-cause hospital admission, and intubation, but no significant difference in quality of life. Noninvasive HMV, compared with no device, was significantly associated with lower risk of hospital admission, but there was no significant difference in mortality risk. However, the evidence was low to moderate in quality, the evidence on quality of life was insufficient, and the analyses for some outcomes were based on small numbers of studies.

Non invasive ventilation in patients with chronic obstructive pulmonary disease in a hospital and at home

Last two decades, active use of non-invasive ventilation (NIV) has provided a significant improvement in the management of chronic obstructive pulmonary disease (COPD), both in patients with acute exacerbation and in stable patients. Currently, NIV is the first-line treatment for patients with acute exacerbation of COPD and acute hypercapnic respiratory failure. This method of respiratory support is also effective after extubation, as it could facilitate weaning from the ventilator and affects positively prevention and treatment of postextubation respiratory failure. Also, NIV has been successfully used in co-morbidity of COPD and sleep apnea syndrome, COPD and pneumonia, and in early postoperative period after thoracic surgery. NIV can be used in COPD patients with chronic respiratory failure. Long-term NIV at home is more reasonable in patients with daytime hypercapnia. The most effective strategy of respiratory support in COPD is thought to be decrease in the partial pressure of carbon dioxide in the arterial blood, i.e. high-intensity NIV. Currently available portable non-invasive ventilators could improve significantly physical activity of patients with severe COPD.

Clinical management of chronic obstructive pulmonary disease patients with muscle dysfunction

Muscle dysfunction is frequently observed in chronic obstructive pulmonary disease (COPD) patients, contributing to their exercise limitation and a worsening prognosis. The main factor leading to limb muscle dysfunction is deconditioning, whereas respiratory muscle dysfunction is mostly the result of pulmonary hyperinflation. However, both limb and respiratory muscles are also influenced by other negative factors, including smoking, systemic inflammation, nutritional abnormalities, exacerbations and some drugs. Limb muscle weakness is generally diagnosed through voluntary isometric maneuvers such as handgrip or quadriceps muscle contraction (dynamometry); while respiratory muscle loss of strength is usually recognized through a decrease in maximal static pressures measured at the mouth. Both types of measurements have validated reference values. Respiratory muscle strength can also be evaluated determining esophageal, gastric and transdiaphragmatic maximal pressures although there is a lack of widely accepted reference equations. Non-volitional maneuvers, obtained through electrical or magnetic stimulation, can be employed in patients unable to cooperate. Muscle endurance can also be assessed, generally using repeated submaximal maneuvers until exhaustion, but no validated reference values are available yet. The treatment of muscle dysfunction is multidimensional and includes improvement in lifestyle habits (smoking abstinence, healthy diet and a good level of physical activity, preferably outside), nutritional measures (diet supplements and occasionally, anabolic drugs), and different modalities of general and muscle training.

The effect of domiciliary noninvasive ventilation on clinical outcomes in stable and recently hospitalized patients with COPD: a systematic review and meta-analysis

Introduction

Noninvasive ventilation (NIV) improves survival among patients with hypercapnic respiratory failure in hospital, but evidence for its use in domiciliary settings is limited. A patient’s underlying risk of having an exacerbation may affect any potential benefit that can be gained from domiciliary NIV. This is the first comprehensive systematic review to stratify patients based on a proxy for exacerbation risk: patients in a stable state and those immediately post-exacerbation hospitalization.

Methods

A systematic review of nonrandomized and randomized controlled trials (RCTs) was undertaken in order to compare the relative effectiveness of different types of domiciliary NIV and usual care on hospital admissions, mortality, and health-related quality of life. Standard systematic review methods were used for identifying studies (until September 2014), quality appraisal, and synthesis. Data were presented in forest plots and pooled where appropriate using random-effects meta-analysis.

Results

Thirty-one studies were included. For stable patients, there was no evidence of a survival benefit from NIV (relative risk [RR] 0.88 [0.55, 1.43], I²=60.4%, n=7 RCTs), but there was a possible trend toward fewer hospitalizations (weighted mean difference −0.46 [−1.02, 0.09], I²=59.2%, n=5 RCTs) and improved health-related quality of life. For posthospital patients, survival benefit could not be demonstrated within the three RCTs (RR 0.89 [0.53, 1.49], I²=25.1%), although there was evidence of benefit from four non-RCTs (RR 0.45 [0.32, 0.65], I²=0%). Effects on hospitalizations were inconsistent. Post hoc analyses suggested that NIV-related improvements in hypercapnia were associated with reduced hospital admissions across both populations. Little data were available comparing different types of NIV.

Conclusion

The effectiveness of domiciliary NIV remains uncertain; however, some patients may benefit. Further research is required to identify these patients and to explore the relevance of improvements in hypercapnia in influencing clinical outcomes. Optimum time points for commencing domiciliary NIV and equipment settings need to be established.

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.

Long-term non-invasive ventilation reduces readmissions in COPD patients with two or more episodes of acute hypercapnic respiratory failure

BACKGROUND

Chronic obstructive pulmonary disease (COPD) patients who have had an episode of acute hypercapnic respiratory failure (AHRF) have a large 1-year risk of death or readmission. Acute non-invasive ventilation (NIV) has been shown to be an effective treatment of AHRF; and long-term NIV (LTNIV) has been shown to be an effective treatment of chronic respiratory failure in stable hypercapnic COPD. We investigated the effects of LTNIV in a group of patients with severe, unstable COPD: frequent admissions and multiple previous episodes of AHRF treated with NIV.

METHODS

We conducted a retrospective analysis of 20 COPD patients treated with LTNIV after two or more episodes of AHRF during 1 year.

RESULTS

The mean number of AHRF episodes decreased from 2.44 in the year prior to LTNIV initiation to 0.44 in the year following (p<0.0001). The median number of admissions decreased from 5.19 to 1.88 (p=0.0092). Four patients (20%) died in 1 year. LTNIV tended to reduce arterial CO2. No changes were found in lung function.

CONCLUSIONS

LTNIV seems effective in reducing recurrent AHRF and readmissions in a highly select group of patients with severe, unstable COPD and frequent AHRF.

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.

Nocturnal non-invasive positive pressure ventilation for stable chronic obstructive pulmonary disease

BACKGROUND

Non-invasive positive pressure ventilation (NIPPV) is effective in treating acute exacerbations of chronic obstructive pulmonary disease (COPD). Nocturnal non-invasive positive pressure ventilation (nocturnal-NIPPV) has been proposed as an intervention for stable hypercapnic patients with COPD.

OBJECTIVES

To assess the effects of nocturnal-NIPPV at home via nasal mask or face mask in people with COPD by using a meta-analysis based on individual patient data (IPD).

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register. We performed the latest search in August 2012.

SELECTION CRITERIA

Randomised controlled trials in people with stable COPD that compared nocturnal-NIPPV at home for at least five hours per night, for at least three consecutive weeks plus standard therapy with standard therapy alone.

DATA COLLECTION AND ANALYSIS

IPD were collected and two review authors assessed risk of bias independently.

MAIN RESULTS

This update of the systematic review on nocturnal-NIPPV in COPD (Wijkstra 2002), has led to the inclusion of three new studies, leading to seven included studies on 245 people. We obtained IPD for all participants in all included studies. The 95% confidence interval (CI) of all outcomes included zero. These included partial pressure of CO2 and O2 in arterial blood, six-minute walking distance (6MWD), health-related quality of life (HRQoL), forced expiratory volume in one second (FEV1), forced vital capacity (FVC), maximal inspiratory pressure (PImax) and sleep efficiency. The mean effect on 6MWD was small at 27.7 m and not statistically significant. Given the width of the 95% CI (-28.1 to 66.3 m), the real effect of NIPPV on 6MWD is uncertain and we cannot exclude an effect that is clinically significant (considering that the minimal clinically difference on 6MWD is around 26 m).

AUTHORS' CONCLUSIONS

Nocturnal-NIPPV at home for at least three months in hypercapnic patients with stable COPD had no consistent clinically or statistically significant effect on gas exchange, exercise tolerance, HRQoL, lung function, respiratory muscle strength or sleep efficiency. Meta-analysis of the two new long-term studies did not show significant improvements in blood gases, HRQoL or lung function after 12 months of NIPPV. However, the small sample sizes of these studies preclude a definite conclusion regarding the effects of NIPPV in COPD.

Effects of long-term non-invasive home mechanical ventilation on chronic respiratory failure

OBJECTIVE

Chronic respiratory failure (CRF) is a syndrome defined by certain disturbances in arterial blood gases. Non-invasive mechanical ventilation (NIMV) is an increasingly used treatment modality in respiratory failure. The aim of this study was to investigate the long-term effects of NIMV on pulmonary function and survival of patients with CRF.

METHODS

The study enrolled 170 CRF patients who it was decided should receive long-term home mechanical ventilation. Patients were stratified into two distinct groups - Group I (patients for whom NIMV was recommended and who had used it) and Group II (patients for whom NIMV was recommended at least 1 year ago but who had not used it for various reasons). Best arterial blood gas and pulmonary function test values in the year before the NIMV recommendation were obtained from patient records. The same tests were performed at least 1 year (1-5 years) after initiation of NIMV therapy in Group I patients and at least 1 year (1-5 years) after prescription of the device in Group II.

RESULTS

In the assessments performed 1 year after NIMV recommendation, no difference was found between groups in terms of hospital admissions. However, in Group I, intra-group analysis showed a reduction in the number of hospitalizations 1 year after NIMV. A marked reduction in PaCO(2) level was found in Group I patients 1 year after NIMV therapy. Mean survival after NIMV recommendation was 40.27 +/- 3.56 months in Group I, and 27.35 +/- 3.68 months in Group II (log rank = 7.79; p = 0.005). It was found that survival time increased as duration of NIMV usage increased.

CONCLUSION

NIMV therapy has some important and significant benefits in patients with hypercapnic chronic respiratory failure. This study has some limitations in terms of patient selection, power analysis and survival analysis. To assess the effects of NIMV on mortality and pulmonary functions, the authors believe that there is need for prospective, controlled, multicentre studies with longer follow-up periods, improved adherence and novel ventilator modes and settings.

Noninvasive ventilation in patients with chronic obstructive airway disease

Recent years have seen the emergence of noninvasive ventilation (NIV) as an important tool for management of patients with acute exacerbation of chronic obstructive pulmonary disease (COPD). Several well conducted studies in the recent years have established its role in the initial, as well as later management of these patients. However, some grey areas remain. Moreover, data is emerging on the role of long term nocturnal NIV use in patients with very severe stable COPD. This review summarizes the evidence supporting the use of NIV in various stages of COPD, discuss the merits as well as demerits of this novel ventilatory strategy and highlight the grey areas in the current body of knowledge.

[Follow-up criteria for community acquired pneumonias and acute exacerbations of chronic obstructive pulmonary disease]

The follow-up of Community Acquired Pneumonias (CAP) and Acute Exacerbations of Chronic Obstructive Pulmonary Diseases (AECOPD) differs with the setting of care, but overall calls upon the same investigations as the initial evaluations. In the event of initial ambulatory care, the evaluation is carried out primarily on clinical data, at the 2 or 3rd day for the CAP, at the 2nd to 5th day for the AECOPD. In the event of unfavourable evolution, or from the start in the most severe cases, the follow-up is carried out in hospital; clinical evaluation is readily daily, and all the more frequent that the clinical condition is worrying because of the severity or risk factors. The investigations will be limited to those initially abnormal in the event of favourable evolution; on the contrary, unfavourable evolution can justify new investigations which depend on clinical characteristics. Remotely, i.e. 4 to 8 weeks later, must be checked the return at the baseline clinical state, a chest X-ray (CAP), spirometry and arterial blood gas (AECOPD), even bronchoscopy and thoracic CT-scan.

Devenir des patients BPCO traités par ventilation non invasive prolongée à domicile

BACKGROUND

The use of domiciliary non-invasive positive pressure ventilation (NIPPV) is still controversial in stable hypercapnic COPD.

METHODS

Records of COPD patients who received home NIPPV from 1990 to 2002 either following an acute exacerbation or because of stable hypercapnia were retrospectively reviewed.

RESULTS

Thirty-seven patients receiving long term oxygen therapy for 50 +/- 47 months were included. At inclusion, their mean +/- SD: FEV1 was 27 +/- 9% predicted, inspiratory capacity was 45 +/- 14% predicted, PaO2 breathing room air was 50 +/- 10 mm Hg, PaCO2 breathing room air = 53 +/- 8 mm Hg, PaCO2 with oxygen was 60 +/- 9 mm Hg. Median survival with NIPPV was 41 months. The 1-year, 3-year and 5-year survival rates with NIPPV were 92%, 62% and 24% respectively. Twelve months after onset of home NIPPV, PaCO2 breathing room air and with oxygen were significantly lower (47 +/- 8 mm Hg, p = 0.028 and 53 +/- 8 mm Hg, p = 0.005, respectively), inspiratory capacity was significantly improved (54 +/- 18% predicted, p = 0.033).

CONCLUSION

This study suggests that home NIPPV allows a lasting physiological stabilization in selected COPD patients, particularly those with an advanced disease, by reducing hypercapnia and improving inspiratory capacity.

Long-term mechanical ventilation and nutrition

Mechanical ventilation (MV) in chronic situations is commonly used, either delivered invasively or by means of non-invasive interfaces, to control hypoventilation in patients with chest wall, neuromuscular or obstructive lung diseases (either in adulthood or childhood). The global prevalence of ventilator-assisted individuals (VAI) in Europe ranges from 2 to 30 per 100000 population according to different countries. Nutrition is a common problem to face with in patients with chronic respiratory diseases: nonetheless, it is a key component in the long-term management of underweight COPD patients whose muscular disfunction may rapidly turn to peripheral muscle waste. Since long-term mechanical ventilation (LTMV) is usually prescribed in end-stage respiratory diseases with poor nutritional status, nutrition and dietary intake related problems need to be carefully assessed and corrected in these patients. This paper aims to review the most recent innovations in the field of nutritional status and food intake-related problems of VAI (both in adulthood and in childhood).

A meta-analysis of nocturnal noninvasive positive pressure ventilation in patients with stable COPD

STUDY OBJECTIVES

The potential benefits of noninvasive positive pressure ventilation (NIPPV) for patients with COPD remains inconclusive, as most studies have included only a small number of patients. We therefore undertook a meta-analysis of randomized controlled trials (RCTs) that compared nocturnal NIPPV with conventional management in patients with COPD and stable respiratory failure.

DESIGN

RCTs were identified from several sources, such as MEDLINE, EMBASE, and CINAHL. In addition, records were identified through hand searching of abstracts from meetings of the American Thoracic Society, the American College of Chest Physicians, and the European Respiratory Society.

PATIENTS

Patients with COPD according to the definition of the American Thoracic Society.

INTERVENTIONS

NIPPV applied via a nasal or facemask for at least 5 h/d for at least 3 weeks. Patients in the actively treated group continued to receive the usual management for COPD. The control group received the same management as the study group but did not receive NIPPV.

MEASUREMENTS AND RESULTS

PaCO(2), PaO(2), 6-min walking distance (6MWD), respiratory muscle function, FEV(1), vital capacity, and sleep efficiency (time asleep as a percentage of total time in bed) were used as outcome measures. The publications were reduced to 10 potentially eligible articles from 164 publications retrieved from computer searches and 8 further abstracts. Four trials were finally included in the meta-analysis. The only outcome for which the confidence intervals excluded zero was maximal inspiratory pressure (PImax). The confidence intervals for the other outcomes included zero. The mean treatment effects for FEV(1) and PImax were small, whereas it was moderate for the 6MWD. Small negative effects were found for the outcomes of vital capacity, PaCO(2), and sleep efficiency.

CONCLUSIONS

This meta-analysis of 3 months of NIPPV in patients with stable COPD showed that ventilatory support did not improve lung function, gas exchange, or sleep efficiency. The high upper limit of the confidence interval for the 6MWD suggested that some people do improve their walking distance. The small overall sample size precluded a clear clinical direction regarding the effects of NIPPV in patients with COPD.

Lack of additional effect of adjunct of assisted ventilation to pulmonary rehabilitation in mild COPD patients

Different modalities of assisted ventilation improve breathlessness and exercise tolerance in patients with chronic obstructive pulmonary disease (COPD). The aim of this study was to evaluate the effects of the addition of assisted ventilation during exercise training on the outcome of a structured pulmonary rehabilitation programme (PRP) in COPD patients. Thirty-three male patients with stable COPD (mean (SD) forced expiratory volume in 1 s (FEV1) 44 (16) % pred), without chronic ventilatory failure, undergoing a 6-week multidisciplinary outpatient PRP including exercise training, were randomised to training during either mask proportional assist ventilation (PAV: 18 patients) or spontaneous breathing (SB: 15 patients). Assessment included exercise tolerance, dyspnoea, leg fatigue, and health-related quality of life (HRQL). Five out of 18 patients (28%) in the PAV group dropped out due to lack of compliance with the equipment. Both groups showed significant post-PRP improvements in exercise tolerance (peak work rate difference: 20 (95% Cl 2.4-37.6) and 14 (3.8% CI to 24.2) W in PAV and SB group, respectively), dyspnoea and leg fatigue, but not in HRQL, without any significant difference between groups. It is concluded that with the modality and in the patients assessed in this study assisted ventilation during training sessions included in a multidisciplinary PRP was not well tolerated by all patients and gave no additional physiological benefit in comparison with exercise training alone.

Ventilation of patients with asthma and chronic obstructive pulmonary disease

Ventilatory intervention is often life-saving when patients with asthma or chronic obstructive pulmonary disease (COPD) experience acute respiratory compromise. Although both noninvasive and invasive ventilation methods may be viable initial choices, which is better depends upon the severity of illness, the rapidity of response, coexisting disease, and capacity of the medical environment. In addition, noninvasive ventilation often relieves dyspnea and hypoxemia in patients with stable severe COPD. On the basis of current evidence, the general principles of ventilatory management common to patients with acutely exacerbated asthma/COPD are these: noninvasive ventilation is suitable for a relatively simple condition, but invasive ventilation is usually required in patients with more complex or more severe disease. It is crucial to provide controlled hypoventilation, longer expiratory time, and titrated extrinsic positive end-expiratory pressure to avoid dynamic hyperinflation and its attendant consequences. Controlled sedation helps achieve synchrony of triggering, power, and breath timing between patient and ventilator. When feasible, noninvasive ventilation often facilitates the weaning of ventilator-dependent patients with COPD and shortens the patient's stay in the intensive care unit.

Nocturnal non-invasive positive pressure ventilation for stable chronic obstructive pulmonary disease

BACKGROUND

Nocturnal non-invasive positive pressure ventilation (NIPPV) might be beneficial in stable hypercapnic patients with chronic obstructive pulmonary disease (COPD). However, evidence remains equivocal as conflicting results have been published.

OBJECTIVES

To determine the effect of nocturnal non-invasive positive pressure ventilation via nasal mask or face mask in patients with COPD.

SEARCH STRATEGY

An initial search was carried out using the Cochrane Airways Group COPD RCT register using the search terms: (nasal ventilat* OR positive pressure OR NIPPV). An additional search was done by hand searching of abstracts from meetings of the American Thoracic Society, British Thoracic Society and European Respiratory Society.

SELECTION CRITERIA

Randomised controlled trials in stable patients with COPD that compared nocturnal non-invasive positive pressure ventilation plus standard therapy with standard therapy alone.

DATA COLLECTION AND ANALYSIS

Data extraction was performed by two independent reviewers.

MAIN RESULTS

The only outcome for which the 95% confidence interval excluded zero was PI max. The 95% confidence interval (CI) of the other outcomes included zero. These included FEV1,FVC, PaCO2, sleep efficiency and 6-minute walking distance (6MWD). The mean effect on 6MWD was modest at 27.5 m, but the 95% CI were wide (-28.1, 81.8 m) suggesting that some patients had a big improvement. Such patients could not be identified a priori.

REVIEWER'S CONCLUSIONS

Nocturnal NIPPV for at least 3 months in hypercapnic patients with stable COPD had no consistent clinically or statistically significant effect on lung function, gas exchange, respiratory muscle strength, sleep efficiency or exercise tolerance. However, the small sample sizes of these studies precludes a definite conclusion regarding the effects of NIPPV in COPD.

Noninvasive mechanical ventilation improves endurance performance in patients with chronic respiratory failure due to thoracic restriction

OBJECTIVE

Treatment with noninvasive mechanical ventilation (NMV) alleviates hypoventilation and improves gas exchange in patients with chronic respiratory failure (CRF) due to thoracic restriction. However, little is known about the effects of NMV on respiratory and peripheral muscle endurance.

DESIGN

Prospective case-control study.

SUBJECTS

Ten patients in clinically stable condition (age, 53.5 +/- 8.2 years [mean +/- SD]) with mild-to-moderate CRF due to thoracic restriction (PCO(2) between 45 mm Hg and 55 mm Hg) were treated with NMV during the night for 3 months. Ten matched patients (age, 52.2 +/- 9.5 years) receiving 3 months of normal care without NMV served as a control group.

INTERVENTION AND MEASUREMENTS

After a 3-day period of familiarization with the endurance tests, all patients performed a baseline preintervention inspiratory threshold loading test, cycle ergometer test, and shuttle walking test on the same day. The endurance tests were then repeated following the 3-month intervention period.

RESULTS

NMV was used on average for 7.1 +/- 0.9 h/d during the 3-month period. There was a significant improvement in endurance time (p < 0.0001) in all three endurance tests in the NMV group compared with the control group. In the NMV group, endurance time increased by 278 +/- 269% during the inspiratory threshold loading test, by 176 +/- 159% during the cycle ergometer test, and by 32 +/- 22% during the shuttle walking test. Significant improvements (p < 0.01) in both PO(2) and PCO(2) were also observed in the NMV group but not in the control group.

CONCLUSIONS

Three months of treatment with NMV increases both respiratory and peripheral muscle endurance in patients with CRF due to thoracic restriction.

Noninvasive ventilation and obstructive lung diseases

The key role of noninvasive positive pressure ventilation (NPPV) is well documented in chronic obstructive pulmonary disease (COPD) patients with acute respiratory failure (ARF) since it may avoid endotrachal intubation in >50% of cases when used as the initial treatment. However, currently only minimal data is available to assess usefulness of NPPV in COPD patients on a long-term basis. Even if such studies are difficult to manage, there is clearly a need for prospective studies comparing long-term oxygen therapy (LTOT) and NPPV in the most severe COPD in a large amount of patients and on a real long-term basis of several years. Two randomized prospective studies are being completed in Europe and the first preliminary results show that NPPV is associated with a reduction of hospitalization for chronic respiratory failure decompensation. The main beneficial effect of long-term mechanical ventilation in COPD patients with chronic respiratory failure implies a correction of nocturnal hypoventilation that could persist beyond the ventilation period because of a temporary improvement in carbon dioxide sensitivity that is often blunted in these patients. A synthesis from the literature suggest to consider NPPV for severe COPD patients who present with chronic hypoxia and hypercapnia and develop an unstable respiratory condition. Instability may be appreciated on a clinical basis and confirmed by a progressive worsening of arterial blood gas tensions, leading to frequent cardiorespiratory decompensations with ominous ARF episodes. NPPV should also be considered after an ARF episode successfully treated by noninvasive ventilation but with the impossibility to wean the patient from the ventilator. Thus, noninvasive positive pressure ventilation could be proposed as a preventive treatment in severe chronic obstructive pulmonary disease patients with unstable respiratory condition associated with fluctuating hypercapnia before, during and after an acute respiratory failure episode, avoiding the need for a tracheotomy. Adjunction of noninvasive ventilation to exercise rehabilitation is under evaluation.

Long-term controlled trial of nocturnal nasal positive pressure ventilation in patients with severe COPD

STUDY OBJECTIVES

To determine the 1-year efficacy of noninvasive positive pressure ventilation (NPPV) added to long-term oxygen therapy (LTOT) in patients with stable severe COPD. PATIENT SELECTION AND METHODS: We prospectively randomized 52 patients with severe COPD (FEV(1) < 45%) to either NPPV plus "standard care" (96% patients with LTOT) or to standard care alone (93% patients with LTOT). The outcomes measured included the following: rate of acute COPD exacerbations; hospital admissions; intubations; and mortality at 3 months, 6 months, and 12 months. The patients were also evaluated at 3 months and 6 months for dyspnea using the Medical Research Council and Borg scales, gas exchange, hematocrit, pulmonary function, cardiac function with echocardiogram, and neuropsychological performance.

RESULTS

One-year survival was similar in both groups (78%). The number of acute exacerbations was similar at all time points in patients receiving NPPV, compared with control subjects. The number of hospital admissions was decreased at 3 months in the NPPV group (5% vs 15% of patients, p < 0.05), but this difference was not seen at 6 months (18% vs 19%, respectively). The only beneficial differences were observed in the Borg dyspnea rating, which dropped from 6 to 5 (p < 0.039), and in one of the neuropsychological tests (psychomotor coordination) for the NPPV group at 6 months.

CONCLUSIONS

Our study indicates that over 1 year, NPPV does not affect the natural course of the disease and is of marginal benefit in outpatients with severe COPD who are in stable condition.

The appropriate setting of noninvasive pressure support ventilation in stable COPD patients

STUDY OBJECTIVE

To evaluate the short-term physiologic effects of two settings of nasal pressure-support ventilation (NPSV) in stable COPD patients with chronic hypercapnia.

DESIGN

Randomized controlled physiologic study.

SETTING

Lung function units and outpatient clinic of two affiliated pulmonary rehabilitation centers.

PATIENTS

Twenty-three patients receiving domiciliary nocturnal NPSV for a mean (+/- SD) duration of 31 +/- 20 months.

METHODS

Evaluation of arterial blood gases, breathing pattern, respiratory muscles, and dynamic intrinsic positive end-expiratory pressure (PEEPi,dyn) during both unassisted and assisted ventilation. Two settings of NPSV were randomly applied for 30 min each: (1) usual setting (U), the setting of NPSV actually used by the individual patient at home; and (2) physiologic setting (PHY), the level of inspiratory pressure support (IPS) and external positive end-expiratory pressure (PEEPe) tailored to patient according to invasive evaluation of respiratory muscular function and mechanics.

RESULTS

All patients tolerated NPSV well throughout the procedure. Mean U was IPS, 16 +/- 3 cm H(2)O and PEEPe, 3.6 +/- 1.4 cm H(2)O; mean PHY was IPS, 15 +/- 3 cm H(2)O and PEEPe, 3.1 +/- 1.6 cm H(2)O. NPSV was able to significantly (p < 0.01) improve arterial blood gases independent of the setting applied. When compared with spontaneous breathing, both settings induced a significant increase in minute ventilation (p < 0.01). Both settings were able to reduce the diaphragmatic pressure-time product, but the reduction was significantly greater with PHY (by 64%; p < 0.01) than with U (56%; p < 0.05). Eleven of 23 patients (48%) with U and 7 of 23 patients (30%) with PHY showed ineffective efforts (IE); the prevalence of IE (20 +/- 39% vs 6 +/- 11% of their respiratory rate with U and PHY, respectively) was statistically different (p < 0.05).

CONCLUSION

In COPD patients with chronic hypercapnia, NPSV is effective in improving arterial blood gases and in unloading inspiratory muscles independent of whether it is set on the basis of patient comfort and improvement in arterial blood gases or tailored to a patient's respiratory muscle effort and mechanics. However, setting of inspiratory assistance and PEEPe by the invasive evaluation of lung mechanics and respiratory muscle function may result in reduction in ineffective inspiratory efforts. These short-term results must be confirmed in the long-term clinical setting.

Randomized controlled trial of domiciliary noninvasive positive pressure ventilation and physical training in severe chronic obstructive pulmonary disease

The addition of noninvasive positive pressure ventilation (NPPV) to an exercise training (ET) program in severe chronic obstructive pulmonary disease (COPD) may produce greater benefits in exercise tolerance and quality of life than after training alone. Forty-five patients with severe stable COPD-mean (SD) FEV(1) 0.96 (0.31) L, Pa(O(2)) 65.4 (9.07) mm Hg, Pa(CO(2)) 45.6 (7.89) mm Hg-were randomized to domiciliary NPPV + ET (n = 23) or ET alone (n = 22). Exercise capacity and health status were assessed at baseline and after an 8-wk training program. There was a significant improvement in mean shuttle walk test (SWT) in the NPPV + ET group: from 169 (112) to 269 (124) m (p = 0.001), compared with the ET group: 205 (100) to 233 (123) m (p = 0.19); mean difference (95% confidence interval [CI]): 72 (12.9 to 131) m. Repeated measures analysis of variance (ANOVA) showed that the differences between the two groups became evident only in the final 4 wk of the training program with a mean end study difference (95% 1CI) of 65.8 (17.1 to 114) m. There was a significant improvement in the Chronic Respiratory Disease Questionnaire (CRDQ) of mean (SD) 24.0 (17.4) (p = < 0.001) in the NPPV + ET group and 11.8 (15.8) (p = 0.003) points in the ET group; mean difference: 12.3 (1.19 to 23.4). Only the NPPV + ET group demonstrated a significant improvement in arterial oxygenation; mean difference: 3.70 mm Hg (0.37 to 7.27). This study suggests that domiciliary NPPV can be used successfully to augment the effects of rehabilitation in severe COPD.