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

The Role of Obstructive Sleep Apnea in Hypercapnic Respiratory Failure Identified in Critical Care, Inpatient, and Outpatient Settings

An emerging body of literature describes the prevalence and consequences of hypercapnic respiratory failure. While device qualifications, documentation practices, and previously performed clinical studies often encourage conceptualizing patients as having a single "cause" of hypercapnia, many patients encountered in practice have several contributing conditions. Physiologic and epidemiologic data suggest that sleep-disordered breathing-particularly obstructive sleep apnea (OSA)-often contributes to the development of hypercapnia. In this review, the authors summarize the frequency of contributing conditions to hypercapnic respiratory failure among patients identified in critical care, emergency, and inpatient settings with an aim toward understanding the contribution of OSA to the development of hypercapnia.

Does PaCO2 correction have an impact on survival of patients with chronic respiratory failure and long-term non-invasive ventilation?

Background and objective

Non-invasive ventilation (NIV) improves survival of patients with chronic respiratory failure (CRF). Most often, pressure settings are made to normalize arterial blood gases. However, this objective is not always achieved due to intolerance to increased pressure or poor compliance. Few studies have assessed the effect of persistent hypercapnia on ventilated patients' survival. Data from the Pays de la Loire Respiratory Health Research Institute cohort were analyzed to answer this question.

Study design and methods

NIV-treated adults enrolled between 2009 and 2019 were divided into 5 subgroups: obesity-hypoventilation syndrome (OHS), COPD, obese COPD, neuromuscular disease (NMD) and chest wall disease (CWD). PaCO2 correction was defined as the achievement of a PaCO2 < 6 kPa or a 20% decrease in baseline PaCO₂ in COPD patients. The endpoint was all-cause mortality. Follow-up was censored in case of NIV discontinuation.

Results

Data from 431 patients were analyzed. Median survival was 103 months and 148 patients died. Overall, PaCO2 correction was achieved in 74% of patients. Bivariate analysis did not show any survival difference between patients who achievedPaCO₂ correction and those who remained hypercapnic: overall population: p = 0.74; COPD: p = 0.97; obese COPD: p = 0.28; OHS: p = 0.93; NMD: p = 0.84; CWD: p = 0.28.

Conclusion

Moderate residual hypercapnia under NIV does not negatively impact survival in CRF patients. In individuals with poor tolerance of pressure increases, residual hypercapnia can therefore be tolerated under long-term NIV. Larger studies, especially with a higher number of patients with residual PaCO2 > 7 kPa, are needed to confirm these results.

Sleep disordered breathing assessment in patient with slowly progressive neuromuscular disease

BACKGROUND

Sleep-disordered breathing (SDB) is common in patients with neuromuscular diseases (NMD). Focusing on hypercapnia may lead to the neglect of other SDB such as obstructive and/or central sleep apnea syndrome (SAS). Our objectives were to assess the risk of inappropriate SDB management according to different screening strategies and to evaluate the prevalence and determinants of isolated and overlapping sleep apnea in patients with slowly progressive NMD.

METHODS

This monocentric, cross-sectional, retrospective study analyzed medical records of adult NMD patients referred to a sleep department. Diagnostic strategies, including respiratory polygraphy (RP), nocturnal transcutaneous capnography (tcCO2), and blood gases (BG), were assessed for their performance in diagnosing SDB. Demographics and pulmonary function test results were compared between patients with or without SDB to identify predictors.

RESULTS

Among the 149 patients who underwent a full diagnostic panel (RP + tcCO2 + BG), 109 were diagnosed with SDB. Of these, 33% had isolated SAS, and central apneas were predominant. Using single diagnostic strategies would lead to inappropriate SDB management in two thirds of patients. A combination of 2 diagnostic tools resulted respectively in 21.1, 22.9 and 42.2 % of inappropriate SDB management for RP + tcCO2, RP + BG and tcCO2 + BG.

CONCLUSION

The significant prevalence of sleep apnea syndrome in patients with slowly progressive NMD highlights the need for increased awareness among clinicians. Improved diagnostics involve a systematic approach addressing both sleep apnea and diurnal and nocturnal alveolar hypoventilation to avoid inappropriate management and limit the consequences of SDB.

Respiratory Management of Patients With Neuromuscular Weakness: An American College of Chest Physicians Clinical Practice Guideline and Expert Panel Report

BACKGROUND

Respiratory failure is a significant concern in neuromuscular diseases (NMDs). This CHEST guideline examines the literature on the respiratory management of patients with NMD to provide evidence-based recommendations.

STUDY DESIGN AND METHODS

An expert panel conducted a systematic review addressing the respiratory management of NMD and applied the Grading of Recommendations, Assessment, Development, and Evaluations approach for assessing the certainty of the evidence and formulating and grading recommendations. A modified Delphi technique was used to reach a consensus on the recommendations.

RESULTS

Based on 128 studies, the panel generated 15 graded recommendations, one good practice statement, and one consensus-based statement.

INTERPRETATION

Evidence of best practices for respiratory management in NMD is limited and is based primarily on observational data in amyotrophic lateral sclerosis. The panel found that pulmonary function testing every 6 months may be beneficial and may be used to initiate noninvasive ventilation (NIV) when clinically indicated. An individualized approach to NIV settings may benefit patients with chronic respiratory failure and sleep-disordered breathing related to NMD. When resources allow, polysomnography or overnight oximetry can help to guide the initiation of NIV. The panel provided guidelines for mouthpiece ventilation, transition to home mechanical ventilation, salivary secretion management, and airway clearance therapies. The guideline panel emphasizes that NMD pathologic characteristics represent a diverse group of disorders with differing rates of decline in lung function. The clinician's role is to add evaluation at the bedside to shared decision-making with patients and families, including respect for patient preferences and treatment goals, considerations of quality of life, and appropriate use of available resources in decision-making.

Medical Electronic Prescription for Home Respiratory Care Services (PEM-CRD) at a Portuguese University Tertiary Care Centre (2014–2018): A Case Study

Home respiratory care (HRC) is the provision of healthcare services at the place of residence of patients or their families, with the aim of meeting needs mainly resulting from chronic respiratory conditions, permanent disability, or terminal illness. In 2016, an innovative electronic prescription system, PEM-CRD, was fully implemented for HRC services in Portugal. To date, no study has addressed the impact of the execution of this digital innovation. For this purpose, we carried out an analysis of the prevalence and number of prescriptions for people with chronic respiratory diseases receiving HRC in the Lisbon metropolitan area, during 2014–2018, using the information obtained from the PEM-CRD database. The data analysis shows that while the number of patients receiving HRC treatment with a prescription has remained stable over the last four years, the number of prescriptions has significantly dropped since 2016 (2016–2018), with consequent paper and processes efficiency. The implementation of the digital Medical Electronic Prescription for Home Respiratory Care tool (PEM-CRD) and consequent dematerialization of these processes has increased the efficiency of prescribing in HRC. Additionally, the possibility of obtaining data through the PEM-CRD allows the monitoring of the evolving prevalence of therapies, improving the health services optimization and allowing reporting on data other than medicines.

Development in PaCO2 over 12 months in patients with COPD with persistent hypercapnic respiratory failure treated with high-flow nasal cannula-post-hoc analysis from a randomised controlled trial

Introduction

Persistent hypercapnic failure in chronic obstructive pulmonary disease (COPD) is associated with poor prognosis. Long-term home non-invasive ventilation is recommended for patients with PaCO₂ >7.0 kPa. Domiciliary high-flow nasal cannula (HFNC) reduces PaCO₂ in short-term studies. This post-hoc analysis examines the effect of HFNC on PaCO₂ levels, exacerbations and admissions in patients with COPD with persistent hypercapnic and hypoxic failures.

Methods

The original trial included 74 long-term oxygen-treated patients (31 HFNC treated/43 controls) with persistent hypercapnic failure (PaCO₂ >6 kPa) who completed the 12-month study period. Baseline data included age, sex, blood gases, exacerbations and hospital admissions in the previous year. Data on blood gases were also recorded at 6 and 12 months for all patients. In addition, acute changes in blood gases after 30 min of HFNC use at site visits were examined, as were exacerbations and hospital admissions during study.

Results

Patients were comparable at baseline. After 12 months there was a 1.3% decrease in PaCO₂ in patients using HFNC and a 7% increase in controls before HFNC use on site (p=0.003). After 30 min of HFNC at visits PaCO₂ changed significantly, with comparable reductions, at 0, 6 and 12 months, including for controls who tried HFNC at study end (p<0.001). The exacerbation rate increased, compared with 12 months prestudy, by 2.2/year for controls (p<0.001) and 0.15/year for HFNC-treated patients (p=0.661). Hospital admission rates increased in the control group,+0.3/year from prestudy (p=0.180), And decreased by 0.67/year (p=0.013)for HFNC-treated patients.

Conclusion

This post-hoc analysis indicates that HFNC stabilises patients with COPD with persistent hypoxic and hypercapnic failures, in terms of PaCO₂, exacerbations and number of hospitalisations, whereas those not receiving HFNC worsened. This suggests that HFNC is a possible treatment for patients with persistent hypercapnic COPD.

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

INTRODUCTION

Although home non-invasive ventilation (NIV) is increasingly used to manage patients with chronic ventilatory failure, there are limited data on the long-term outcome of these patients. Our aim was to report on home NIV populations and the long-term outcome from two European centres.

METHODS

Cohort analysis including all patients established on home NIV from two European centres between 2008 and 2014.

RESULTS

Home NIV was initiated in 1746 patients to treat chronic ventilatory failure caused by (1) obesity hypoventilation syndrome±obstructive sleep apnoea (OHS±OSA) (29.5%); (2) neuromuscular disease (NMD) (22.7%); and (3) obstructive airway diseases (OAD) (19.1%). Overall cohort median survival following NIV initiation was 6.6 years. Median survival varied by underlying aetiology of respiratory failure: rapidly progressive NMD 1.1 years, OAD 2.7 years, OHS±OSA >7 years and slowly progressive NMD >7 years. Multivariate analysis demonstrated higher mortality in patients with rapidly progressive NMD (HR 4.78, 95% CI 3.38 to 6.75), COPD (HR 2.25, 95% CI 1.64 to 3.10), age >60 years at initiation of home NIV (HR 2.41, 95% CI 1.92 to 3.02) and NIV initiation following an acute admission (HR 1.38, 95% CI 1.13 to 1.68). Factors associated with lower mortality were NIV adherence >4 hours per day (HR 0.64, 95% CI 0.51 to 0.79), OSA (HR 0.51, 95% CI 0.31 to 0.84) and female gender (HR 0.79, 95% CI 0.65 to 0.96).

CONCLUSION

The mortality rate following initiation of home NIV is high but varies significantly according to underlying aetiology of respiratory failure. In patients with chronic respiratory failure, initiation of home NIV following an acute admission and low levels of NIV adherence are poor prognostic features and may be amenable to intervention.

The pattern of use and survival outcomes of a dedicated adult Home Ventilation and Respiratory Support Service in Singapore: a 7-year retrospective observational cohort study

Background

In Singapore, a dedicated adult multidisciplinary Home Ventilation and Respiratory Support Service (HVRSS) was set-up to assist individuals with chronic ventilatory failure. We aimed to study the use, survival outcomes and identify factors influencing survival in our cohort of ventilator-assisted individuals (VAIs).

Methods

We retrospectively reviewed all referrals to HVRSS from 2009 to 2015. All VAIs were included and divided into 4 categories: (I) amyotrophic lateral sclerosis (ALS); (II) other neuromuscular and chest wall disease (NMCW); (III) spinal cord injury (SCI); and (IV) complex intensive care unit (ICU) groups for comparison of baseline characteristics, co-morbidities, therapy details and survival outcomes. Cox proportional analysis was used to identify important factors influencing survival for ALS and non-ALS VAIs.

Results

There were 112 VAIs; most were male (63%) and ethnic Chinese (83%). At baseline, median [interquartile range (IQR)] age was 61 [46-69] years, body mass index was 20.2 (17.1-23.8) kg/m² and forced vital capacity was 38 [24-65] %predicted. The three most common diseases were ALS (43%), SCI (13%) and congenital muscular dystrophies (6%). Seventy-four (66%) VAIs received non-invasive ventilation (NIV). Median survival for ALS, Complex ICU, SCI and NMCW VAIs were 1.8, 2.6, 4.2 and 6.7 years respectively. In ALS, NIV conversion to invasive mechanical ventilation (IMV) was associated with longer survival [hazard ratio (HR) 0.24]. In non-ALS VAIs, older age (HR 1.40) and cardiovascular comorbidities (HR 2.61) were poor prognostic factors.

Conclusions

The HVRSS managed a heterogenous group of VAIs in Singapore and survival is comparable to published cohorts. ALS had the worst survival whereas NMCW had the best survival with Complex ICU and SCI groups in between. Transition from NIV to IMV, age and cardiovascular disease were important prognostic factors.

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.

National survey: current prevalence and characteristics of home mechanical ventilation in Hungary

BACKGROUND

Home mechanical ventilation is an established treatment for chronic respiratory failure resulting in improved survival and quality of life. Technological advancement, evolving health care reimbursement systems and newly implemented national guidelines result in increased utilization worldwide. Prevalence shows great geographical variations and data on East-Central European practice has been scarce to date. The aim of the current study was to evaluate prevalence and characteristics of home mechanical ventilation in Hungary.

METHODS

We conducted a nationwide study using an online survey focusing on patients receiving ventilatory support at home. The survey focused on characterization of the site (affiliation, type), experience with home mechanical ventilation, number of patients treated, indication for home mechanical ventilation (disease type), description of home mechanical ventilation (invasive/noninvasive, ventilation hours, duration of ventilation) and description of the care provided (type of follow up visits, hospitalization need, reimbursement).

RESULTS

Our survey uncovered a total of 384 patients amounting to a prevalence of 3.9/100,000 in Hungary. 10.4% of patients received invasive, while 89.6% received noninvasive ventilation. The most frequent diagnosis was central hypopnea syndromes (60%), while pulmonary (20%), neuromuscular (11%) and chest wall disorders (7%) were less frequent indications. Daily ventilation need was less than 8 h in 74.2%, between 8 and 16 h in 15.4% and more than 16 h in 10.4% of patients reported. When comparing sites with a limited (< 50 patients) versus substantial (> 50 patients) case number, we found the former had significantly higher ratio of neuromuscular conditions, were more likely to ventilate invasively, with more than 16 h/day ventilation need and were more likely to provide home visits and readmit patients (p < 0,001).

CONCLUSIONS

Our results show a reasonable current estimate and characterization of home mechanical ventilation practice in Hungary. Although a growing practice can be assumed, current prevalence is still markedly reduced compared to international data reported, the duality of current data hinting to a possible gap in diagnosis and care for more dependent patients. This points to the importance of establishing home mechanical ventilation centers, where increased experience will enable state of the art care to more dependent patients as well, increasing overall prevalence.