Clinical impact of episodic nocturnal hypercapnia and its treatment with noninvasive positive pressure ventilation in patients with stable advanced COPD

Detection of episodic nocturnal hypercapnia in patients with neurodegenerative disorders

PURPOSE

Episodic nocturnal hypercapnia (eNH) in transcutaneous carbon dioxide pressure (PtcCO2) corresponding to rapid eye movement sleep hypoventilation is a useful biomarker for detecting nocturnal hypoventilation. However, the relationship between eNH and neurodegenerative diseases with sleep-related breathing disorders (SRBDs) is unknown. The aim of this study was to evaluate the relationship between eNH and nocturnal hypoventilation in neurodegenerative diseases.

METHODS

Patients with neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), multiple system atrophy (MSA), Parkinson's disease, progressive supranuclear palsy, corticobasal syndrome, and idiopathic normal pressure hydrocephalus, were enrolled and received overnight PtcCO2 monitoring. The patients were divided into groups for eNH and sleep-associated hypoventilation (SH) prevalence analysis: A (ALS), B (MSA), and C (others).

RESULTS

Among 110 patients, twenty-three (21%) and 10 (9%) of the patients met eNH and SH criteria, respectively. eNH and SH were significantly more frequent in groups A and B than in C. The prevalence of SH in the patients with eNH was 39% whereas most of patients with SH (90%) presented with eNH. Among patients with daytime carbon dioxide pressure in arterial blood ≤ 45 mmHg, eNH frequency was 13%, whereas none of the patients met SH criteria. The frequency of noninvasive positive pressure ventilation after PtcCO2 monitoring was significantly higher in those with than without eNH.

CONCLUSIONS

eNH is common in patients with MSA and ALS who present with SRBD. eNH with overnight PtcCO2 monitoring is a useful biomarker to detect hypoventilation among neurodegenerative diseases with different SRBD mechanisms.

Sleep Hypoventilation is Common in Diurnal Normocapnic COPD Patients with Severe or Very Severe Obstruction and is Not Associated with Body Mass Index

Sleep hypoventilation (SH) is common in COPD patients with diurnal hypercapnia, however there are little data on the presence of SH in COPD patients with diurnal normocapnia. In this study the prevalence of SH in stable normocapnic COPD patients with severe or very severe obstruction (GOLD stages III and IV) was evaluated across body mass index (BMI) classes and associations between SH and body composition measures were explored. A total of 56 diurnal normocapnic COPD patients, of whom 17 normal-weight (COPD_NW), 18 overweight (COPD_OW) and 21 obese (COPD_OB), underwent polysomnography to objectify SH and bioelectrical impedance analysis to assess body composition. The overall prevalence of SH was 66.1% and was not different across BMI classes. Logistic regression models indicated that SH was not associated with waist-to-hip ratio, body fat percentage and fat-free mass index. Our data indicate that SH is common in diurnal normocapnic COPD patients with severe or very severe obstruction and is not associated with BMI or body composition.

The Overlap Syndrome of Obstructive Sleep Apnea and Chronic Obstructive Pulmonary Disease: A Systematic Review

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) are common diseases that strongly impact the quality and length of life. Their coexistence is determined by overlap syndrome (OS). This systematic review aims to define the significance of these comorbidities according to the current state of knowledge. For this systematic review, we searched PubMed, Scopus, and Cochrane for studies published between 2018 and 26 October 2022, to find original, observational, human studies published in English, where the diagnosis of COPD was according to the Global Initiative for Obstructive Lung Disease guidelines and the diagnosis of OSA was based on polysomnography. The quality of studies was assessed using the Newcastle-Ottawa quality assessment tool for cohort and case-control studies, as well as its modification for cross-sectional studies. Of the 1548 records identified, 38 were eligible and included in this systematic review. The included studies covered a total population of 27,064 participants. This paper summarizes the most important, up-to-date information regarding OS, including the prevalence, meaning of age/gender/body mass index, polysomnography findings, pulmonary function, comorbidities, predicting OSA among COPD patients, and treatment of this syndrome.

Relationship Between Episodic Nocturnal Hypercapnia and History of Exacerbations in Patients with Advanced Chronic Obstructive Pulmonary Disease

Purpose

An episodic increase in transcutaneous carbon dioxide pressure (PtcCO₂) is often recognized in patients with advanced chronic obstructive pulmonary disease (COPD) by overnight PtcCO₂ monitoring. This phenomenon, called episodic nocturnal hypercapnia (eNH), mainly corresponds to rapid eye movement (REM) sleep-related hypoventilation. However, it is unclear whether eNH is associated with the frequency of COPD exacerbation. We aimed to investigate whether a relationship exists between COPD exacerbation and eNH.

Patients and Methods

We enrolled consecutive patients with stable, severe, or very severe COPD with a daytime arterial carbon dioxide pressure (PaCO₂) <55.0 mmHg who underwent overnight PtcCO₂ monitoring from April 2013 to January 2017. We retrospectively analyzed the prevalence of eNH and sleep-associated hypoventilation (SH) as defined by the American Academy of Sleep Medicine. Moreover, we compared the relationship between the frequency of COPD exacerbations in the previous year and eNH or SH.

Results

Twenty-four patients were included in this study. The study patients had a mean daytime PaCO₂ and nocturnal PtcCO₂ of 43.3 ± 6.8 mmHg and 42.9 ± 9.6 mmHg, respectively. Six (25.0%) and 11 (45.9%) of the 24 patients met the SH and eNH criteria, respectively. The odds ratios of SH and eNH for at least one annual exacerbation were 1.0 [95% confidence interval (CI): 0.16–6.00] and 11.1 [95% CI: 1.39–87.7], respectively. The odds ratios of SH and eNH for at least two annual exacerbations were 0.3 [95% CI: 0.04–2.64] and 6.6 [95% CI: 1.06–39.4], respectively.

Conclusion

In patients with advanced COPD and a daytime PaCO₂ <55.0 mmHg, eNH may be associated with a history of more frequent exacerbations than SH. Further studies are required to validate these findings.

Impact of sleep-related hypoventilation in patients with pleuroparenchymal fibroelastosis

BACKGROUND

Pleuroparenchymal fibroelastosis (PPFE) is a rare fibrosing lung disease with a predilection for the upper lobe and its progression causes hypoventilation, resulting in hypercapnia. Even though the association between sleep-related hypoventilation (SRH) and chronic obstructive pulmonary disease was well documented, its impact in patients with PPFE was not evaluated. The aim of this study is to clarify the impact of SRH on prognosis in PPFE.

METHODS

A retrospective review of the medical records of 52 patients with PPFE who underwent transcutaneous carbon dioxide monitoring during sleep was done. Patients were stratified into SRH (n = 28) and non-SRH (n = 24) groups based on American Academy of Sleep Medicine criteria. The impact of SRH on the prognosis of PPFE, as well as the clinical factors and comorbidities of PPFE associated with SRH, were evaluated.

RESULTS

Forced expiratory volume in the first second (FEV₁), forced vital capacity (FVC), total lung capacity (TLC), and carbon monoxide diffusing capacity (DLco) in the SRH group were significantly lower than the non-SRH group (P < .01). Chronic pulmonary aspergillosis (CPA) was found at a higher rate in the SRH group (P = .02). The median survival time for SRH patients was 330 days, whereas roughly 80% of non-SRH patients were alive during the 3-year observation period (P < .01). Body mass index was a significant prognostic factor in PPFE patients with SRH (HR .78; 95% CI; .64-.94; P < .01). Home oxygen therapy (HOT) during the day and noninvasive positive pressure ventilation (NPPV) at night while sleeping tended to improve prognosis in the SRH group, as indicated by HR of .25 (P = .07).

CONCLUSIONS

SRH may be a poor prognostic factor for PPFE. Additionally, SRH may modify susceptibility to Aspergillosis in patients with PPFE. HOT plus NPPV may improve the disease outcomes in patients with SRH.

Characteristics of the nocturnal desaturation waveform pattern of SpO2 in COPD patients: an observational study

BACKGROUND

Nocturnal desaturation is common in patients with chronic obstructive pulmonary disease (COPD) and impacts disease exacerbation and prognosis. In our previous study, we developed a diagnostic algorithm to classify nocturnal desaturation from SpO₂ waveform patterns based on data from patients receiving home oxygen therapy. In this study, we aimed to investigate nocturnal desaturation in patients with COPD based on SpO₂ waveform patterns and the associations between the waveforms and clinical data.

METHODS

We investigated patients diagnosed with COPD and measured SpO₂ and nasal airflow with a type 4 portable long-term recordable pulse oximeter. Then, we classified the SpO₂ waveforms with the algorithm and compared the clinical data.

RESULTS

One hundred fifty-three patients (136 male and 17 female) were analysed. One hundred twenty-eight of the 153 (83.7%) patients had nocturnal desaturation, with an intermittent pattern (70.6%), sustained pattern (13.1%) and periodic pattern (68.0%). Intriguingly, desaturation with an intermittent pattern was associated with the apnoea-hypopnea index obtained with the portable monitor, and desaturation with a sustained pattern was associated with the cumulative percentage of time at a SpO₂ below 90%.

CONCLUSIONS

We found that nocturnal desaturation was frequently observed in patients with COPD and could be classified into 3 types of waveform patterns.

Prospective Study of Nocturnal Desaturation in Patients Receiving Home Oxygen Therapy

Objective Nocturnal desaturation is common in patients with chronic respiratory disease and often worsens the prognosis. Therefore, it should be diagnosed accurately and appropriately treated. The aim of this study was to clarify the diversity of nocturnal desaturation. Methods We prospectively enrolled 58 outpatients diagnosed with chronic respiratory disease receiving home oxygen therapy and measured nocturnal SpO₂ using a portable oximeter. We classified nocturnal desaturation (3% decrease in SpO₂ from baseline) into three patterns: periodic pattern (desaturation duration of <655 seconds), sustained pattern (desaturation duration of ≥655 seconds), and intermittent pattern (desaturation and recovery of SpO₂ repeated with a cycle of several minutes). Results Nocturnal hypoxemia (SpO₂≤88% for more than 5 minutes) was found in 23.8% of patients. The percentage of patients with chronic obstructive pulmonary disease (COPD) was significantly higher in the nocturnal hypoxemia group than in the non-hypoxemia group (80% vs. 40.6%, p=0.03). Desaturation with a periodic pattern was found in 81% of patients, desaturation with a sustained pattern was found in 40.5% of patients, and desaturation with an intermittent pattern was found in 59.5% of patients. In patients with COPD, desaturation with a periodic pattern was found in 85.7%, desaturation with a sustained pattern was found in 47.6%, and desaturation with an intermittent pattern was found in 57.1%. Conclusion The SpO₂ waveform of nocturnal hypoxemia was able to be classified into three patterns. Suitable treatment for each pattern might improve the prognosis of these patients.

Sleep disordered breathing and chronic obstructive pulmonary disease: a narrative review on classification, pathophysiology and clinical outcomes

Chronic obstructive pulmonary disease (COPD) causes load-capacity-drive imbalance in both wakefulness and sleep, principally driven by expiratory flow limitation and hyperinflation. Sleep imposes additional burdens to the respiratory muscle pump, driven by changes in respiratory muscle tone, neural respiratory drive and consequences of the supine position. COPD patients are therefore at higher risk of decompensation during sleep, which may manifest as altered sleep architecture, isolated nocturnal desaturation, sleep hypoventilation and restless legs. Each form of sleep disordered breathing in COPD is associated with adverse clinical and patient-reported outcomes, including increased risk of exacerbations, hospitalisation, cardiovascular events, reduced survival and poorer quality of life. COPD-obstructive sleep apnoea (OSA) overlap syndrome represents a distinct clinical diagnosis, in which clinical outcomes are significantly worse than in either disease alone, including increased mortality, risk of cardiovascular events, hospitalisation and exacerbation frequency. Sleep disordered breathing is under-recognised by COPD patients and their clinicians, however early diagnosis and management is crucial to reduce the risk of adverse clinical outcomes. In this narrative review, we describe the pathophysiology of COPD and physiological changes that occur during sleep, manifestations and diagnosis of sleep disordered breathing in COPD and associated clinical outcomes.

Treatment of severe stable COPD: the multidimensional approach of treatable traits

Now that additional treatment options for severe chronic obstructive pulmonary disease (COPD) have emerged in recent years, patients with severe COPD should not be left in the rather hopeless situation of “there is nothing to improve” any more. Inertia or fatalism is a disservice to our patients. Ranging from advanced care planning to quite intense and demanding therapies such as multidisciplinary pulmonary rehabilitation, (endoscopic) lung volume reduction, chronic noninvasive ventilation and lung transplantation, caregivers should try to provide a personalised treatment for every severe COPD patient. In this review, we aim to describe the multidimensional approach to these patients at our centre along the lines of treatable traits leading to specific additional treatment modalities on top of standard care.

Severe COPD is not hopeless; in light of treatment options such as pulmonary rehabilitation, bronchoscopic lung volume reduction, chronic noninvasive ventilation and lung transplantation, every patient deserves a personalised assessment of treatable traitshttps://bit.ly/2TO7jxB

Noninvasive volume-assured pressure support for chronic respiratory failure: a review

PURPOSE OF REVIEW

Noninvasive ventilation (NIV) is an established treatment for chronic hypercapnic respiratory failure (CRF). Volume-assured pressure support (VAPS) is a mode of NIV that automatically adjusts inspiratory pressure in order to maintain a constant respiratory volume. We aim to discuss the role and application of VAPS in CRF.

RECENT FINDINGS

Recently published meta-analyses and reviews fail to demonstrate a significant difference in gas exchange, sleep, or quality-of-life improvement between VAPS and bilevel positive airway pressure (BPAP) in patients with CRF. A recent manuscript suggests that VAPS therapy in chronic obstructive pulmonary disease patients may reduce the number of exacerbations. It has been shown that with a protocol-driven approach BPAP and VAPS can both be successfully titrated during a single split-night polysomnography.

SUMMARY

VAPS is as effective as other modes of NIV at improving ventilation and sleep in CRF. The potential advantage is a more consistent ventilatory support through daytime-nighttime variations and progression of disease over time. However, the impact on long-term outcomes, such as survival, has not been studied.

European Respiratory Society guidelines on long-term home non-invasive ventilation for management of COPD

Background

While the role of acute non-invasive ventilation (NIV) has been shown to improve outcome in acute life-threatening hypercapnic respiratory failure in COPD, the evidence of clinical efficacy of long-term home NIV (LTH-NIV) for management of COPD is less. This document provides evidence-based recommendations for the clinical application of LTH-NIV in chronic hypercapnic COPD patients.

Materials and methods

The European Respiratory Society task force committee was composed of clinicians, methodologists and experts in the field of LTH-NIV. The committee developed recommendations based on the GRADE (Grading, Recommendation, Assessment, Development and Evaluation) methodology. The GRADE Evidence to Decision framework was used to formulate recommendations. A number of topics were addressed under a narrative format which provides a useful context for clinicians and patients.

Results

The task force committee delivered conditional recommendations for four actionable PICO (target population-intervention-comparator-outcome) questions, 1) suggesting for the use of LTH-NIV in stable hypercapnic COPD; 2) suggesting for the use of LTH-NIV in COPD patients following a COPD exacerbation requiring acute NIV 3) suggesting for the use of NIV settings targeting a reduction in carbon dioxide and 4) suggesting for using fixed pressure support as first choice ventilator mode.

Conclusions

Managing hypercapnia may be an important intervention for improving the health outcome of COPD patients with chronic respiratory failure. The task force conditionally supports the application of LTH-NIV to improve health outcome by targeting a reduction in carbon dioxide in COPD patients with persistent hypercapnic respiratory failure. These recommendations should be applied in clinical practice by practitioners that routinely care for chronic hypercapnic COPD patients.

Home mechanical ventilation for chronic obstructive pulmonary disease: What next after the HOT-HMV trial?

The benefits of acute non-invasive ventilation to treat acidotic exacerbations of chronic obstructive pulmonary disease (COPD) are well-established. Until recently, the evidence for home mechanical ventilation (HMV) to treat patients with stable COPD had been lacking. This has subsequently been addressed by the application of higher levels of pressure support combined with targeted management of chronic respiratory failure, which demonstrated a reduction in all-cause mortality. Similarly, the previous trial of home oxygen therapy (HOT) and HMV delivered following an acute exacerbation failed to demonstrate an improvement in outcome. With the focus on patients with persistent hypercapnic respiratory failure in the recovery phase following a life-threatening exacerbation combined with targeted reduction in carbon dioxide, HOT and HMV (HOT-HMV) was shown to be clinically effective in reducing the time to readmission or death and cost effective in both the United Kingdom and United States healthcare systems. Future work will need to focus on promoting adherence to home ventilation and novel auto-titrating ventilator modes to facilitate and optimize the set-up of overnight ventilatory support in different target population such as COPD patients with obstructive sleep apnoea and COPD patients with episodic nocturnal hypoventilation.

Prevalence and Predictors of Obstructive Sleep Apnea in Patients with Chronic Obstructive Pulmonary Disease Undergoing Inpatient Pulmonary Rehabilitation

The aim of our study was to evaluate the prevalence and predictors of obstructive sleep apnea (OSA) in patients with chronic obstructive pulmonary disease (COPD) undergoing inpatient pulmonary rehabilitation programs (PRPs). A retrospective data review of consecutive stable patients with a known diagnosis of COPD, admitted for PRP between January 2007 and December 2013. Full overnight polysomnography (PSG) and Epworth Sleepiness Scale (ESS) were assessed in all patients. Out of 422 evaluated patients, 190 (45%) showed an Apnea Hypopnea Index (AHI) ≥ 15 events/hour and underwent OSA treatment. Patients with OSA were significantly younger and had a less severe airway obstruction as compared to patients without OSA. There were no significant differences in cardiac comorbidities nor in arterial blood gases. As expected, patients with OSA showed significantly more severe diurnal symptoms, as assessed by the ESS and higher body mass index (BMI). However, only 69 out of 190 patients with OSA (36.3%) showed an ESS >10, whereas 25% of them had BMI ≤25 and 41% of them had a BMI <30. In all, 68% of patients with OSA were discharged with continuous positive airway pressure (CPAP), 15% with Bilevel ventilation, and 17% without any ventilatory treatment. In conclusion, in the population studied, the combination of OSA and COPD was frequent. BMI and ESS values commonly considered cutoff values for the prediction of OSA in the general population may not be accurate in a subgroup of patients with COPD.