Effect of morphine on breathlessness and exercise endurance in advanced COPD: a randomised crossover trial

Lung Hyperinflation as Treatable Trait in Chronic Obstructive Pulmonary Disease: A Narrative Review

Lung hyperinflation (LH) is a common clinical feature in patients with chronic obstructive pulmonary disease (COPD). It results from a combination of reduced elastic lung recoil as a consequence of irreversible destruction of lung parenchyma and expiratory airflow limitation. LH is an important determinant of morbidity and mortality in COPD, partially independent of the degree of airflow limitation. Therefore, reducing LH has become a major target in the treatment of COPD over the last decades. Advances were made in the diagnostics of LH and several effective interventions became available. Moreover, there is increasing evidence suggesting that LH is not only an isolated feature in COPD but rather part of a distinct clinical phenotype that may require a more integrated management. This narrative review focuses on the pathophysiology and adverse consequences of LH, the assessment of LH with lung function measurements and imaging techniques and highlights LH as a treatable trait in COPD. Finally, several suggestions regarding future studies in this field are made.

European Respiratory Society clinical practice guideline on symptom management for adults with serious respiratory illness

Respiratory symptoms are ubiquitous and impair health-related quality of life in people with respiratory disease. This European Respiratory Society (ERS) task force aimed to provide recommendations for symptomatic treatment in people with serious respiratory illness. The ERS task force comprised 16 members, including representatives of people with serious respiratory illness and informal caregivers. Seven questions were formulated, six in the PICO (Population, Intervention, Comparison, Outcome) format, which were addressed with full systematic reviews and evidence assessed using GRADE (Grading of Recommendations Assessment, Development and Evaluation). One question was addressed narratively. An "evidence-to-decision" framework was used to formulate recommendations. To treat symptoms in people with serious respiratory illness, the task force suggests the use of graded exercise therapy (conditional recommendation, low certainty of evidence); and suggests the use of a multicomponent services, handheld fan and breathing techniques (conditional recommendations, very low certainty of evidence). The task force suggests not to use opioids (conditional recommendation, very low certainty of evidence); and suggests either administering or not administering supplemental oxygen therapy (conditional recommendation, low certainty of evidence). The task force suggests that needs assessment tools may be used as part of a comprehensive needs assessment, but do not replace patient-centred care and shared decision making (conditional recommendation, low certainty of evidence). The low certainty of evidence, modest impact of interventions on patient-centred outcomes, and absence of effective strategies to ameliorate cough highlight the need for new approaches to reduce symptoms and enhance wellbeing for individuals who live with serious respiratory illness.

Management of Refractory Chronic Obstructive Pulmonary Disease: A Review

Chronic obstructive pulmonary disease (COPD) is a common condition with an estimated prevalence of 12% in adults over the age of 30 years worldwide. COPD is a leading cause of morbidity and mortality globally, with a substantial economic and social burden. There are an estimated 3 million deaths annually due to COPD. However, most of the patients with COPD respond to routine interventions like bronchodilator therapy, assessing supplemental oxygen needs, smoking cessation, vaccinations, and pulmonary rehabilitation. There is a significant number of patients who unfortunately progress to have persistent symptoms despite these interventions. Refractory COPD is not yet formally defined. Patients with severe persistent symptoms or exacerbations despite appropriate care can be considered to have refractory COPD. Managing refractory COPD needs a multidimensional approach. In this review article, we will discuss essential interventions like ensuring adequate inhaler techniques, exploring the need for non-invasive ventilatory support, use of chronic antibiotics and phosphodiesterase inhibitors to advanced therapies like bronchoscopic lung volume reduction surgery, and the upcoming role of anti-IL5 agents in managing patients with refractory COPD. We will also discuss non-pharmacologic interventions like psycho-social support and nutritional support. We will conclude by discussing the palliative care aspect of managing patients with refractory COPD. Through this review article, we aim to better the approach to managing patients with refractory COPD and discuss new upcoming therapies.

Effectiveness and safety of opioids on breathlessness and exercise endurance in patients with chronic obstructive pulmonary disease: A systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Opioids are recommended to treat advanced refractory dyspnoea despite optimal therapy by the American Thoracic Society clinical practice guidelines, while newly published randomised controlled trials of opioids in chronic obstructive pulmonary disease yield conflicting results.

AIM

This study aimed to evaluate the effectiveness and safety of opioids for patients with chronic obstructive pulmonary disease.

DESIGN

Systematic review and meta-analysis (PROSPERO CRD42021272556).

DATA SOURCES

Databases of PubMed, EMBASE and CENTRAL were searched from inception to 2022 for eligible randomised controlled trials.

RESULTS

Twenty-four studies including 975 patients, were included. In cross-over studies, opioids improved breathlessness (standardised mean difference, -0.43; 95% CI, -0.55 to -0.30; I2 = 18%) and exercise endurance (standardised mean difference, 0.22; 95% CI, 0.02-0.41; I2 = 70%). However, opioids failed to improve dyspnoea (standardised mean difference, -0.02; 95% CI, -0.22 to 0.19; I2 = 39%) and exercise endurance (standardised mean difference, 0.00; 95% CI, -0.27 to 0.27; I2 = 0%) in parallel control studies that administered sustained-release opioids for more than 1 week. The opioids used in most crossover studies were short-acting and rarely associated with serious adverse effects. Only minor side effects such as dizziness, nausea, constipation and vomiting were identified for short-acting opioids.

CONCLUSIONS

Sustained-release opioids did not improve dyspnoea and exercise endurance. Short-acting opioids appeared to be safe, have potential to lessen dyspnoea and improve exercise endurance, supporting benefit in managing episodes of breathlessness and providing prophylactic treatment for exertional dyspnoea.

Fixed-intensity exercise tests to measure exertional dyspnoea in chronic heart and lung populations: a systematic review

INTRODUCTION

Exertional dyspnoea is the primary diagnostic symptom for chronic cardiopulmonary disease populations. Whilst a number of exercise tests are used, there remains no gold standard clinical measure of exertional dyspnoea. The aim of this review was to comprehensively describe and evaluate all types of fixed-intensity exercise tests used to assess exertional dyspnoea in chronic cardiopulmonary populations and, where possible, report the reliability and responsiveness of the tests.

METHODS

A systematic search of five electronic databases identified papers that examined 1) fixed-intensity exercise tests and measured exertional dyspnoea, 2) chronic cardiopulmonary populations, 3) exertional dyspnoea reported at isotime or upon completion of fixed-duration exercise tests, and 4) published in English.

RESULTS

Searches identified 8785 papers. 123 papers were included, covering exercise tests using a variety of fixed-intensity protocols. Three modes were identified, as follows: 1) cycling (n=87), 2) walking (n=31) and 3) other (step test (n=8) and arm exercise (n=2)). Most studies (98%) were performed on chronic respiratory disease patients. Nearly all studies (88%) used an incremental exercise test. 34% of studies used a fixed duration for the exercise test, with the remaining 66% using an exhaustion protocol recording exertional dyspnoea at isotime. Exertional dyspnoea was measured using the Borg scale (89%). 7% of studies reported reliability. Most studies (72%) examined the change in exertional dyspnoea in response to different interventions.

CONCLUSION

Considerable methodological variety of fixed-intensity exercise tests exists to assess exertional dyspnoea and most test protocols require incremental exercise tests. There does not appear to be a simple, universal test for measuring exertional dyspnoea in the clinical setting.

Caring for patients with advanced COPD: beyond the inhalers…

COPD affects millions of people worldwide. Patients with advanced COPD have a high symptom burden. Breathlessness, cough and fatigue are frequent daily symptoms. Guidelines often focus on pharmacological treatment, especially inhaler therapy, but other approaches in combination with medications offer symptomatic benefit. In this review, we take a multidisciplinary approach with contributions from pulmonary physicians, cardiothoracic surgeons and a physiotherapist. The following areas are addressed: oxygen therapy and noninvasive ventilation (NIV), dyspnoea management, surgical and bronchoscopic options, lung transplantation and palliative care. Oxygen therapy prescribed within guidelines improves mortality in patients with COPD. NIV guidelines offer only low-certainty instruction on the use of this therapy on the basis of the limited available evidence. Dyspnoea management can take place through pulmonary rehabilitation. Specific criteria aid decisions on referral for lung volume reduction treatments through surgical or bronchoscopic approaches. Lung transplantation requires precise disease severity assessment to determine which patients have the most urgent need for lung transplantation and are likely to have the longest survival. The palliative approach runs in parallel with these other treatments, focusing on symptoms and aiming to improve the quality of life of patients and their families facing the problems associated with life-threatening illness. In combination with appropriate medication and an individual approach to symptom management, patients' experiences can be optimised.

Educational aims

To understand the multidisciplinary approach to management of patients with advanced COPD.To recognise the parallel approaches to oxygen, NIV and dyspnoea management with consideration of more interventional options with lung volume reduction therapy or lung transplantation.To understand the high level of symptomatology present in advanced COPD and the relevance of palliative care alongside optimal medical management.

Current pharmacological strategies for symptomatic reduction of persistent breathlessness - a literature review

INTRODUCTION

Persistent breathlessness is a debilitating symptom that is prevalent in the community, particularly in people with chronic and life-limiting illnesses. Treatment includes different steps, including pharmacological treatment aiming to improve the symptom and optimize people's wellbeing.

AREAS COVERED

PubMed and Google Scholar were screened using 'chronic breathlessness' OR 'persistent breathlessness,' AND 'pharmacological treatment,' OR 'opioids.' This review focuses on pharmacological treatments to reduce persistent breathlessness and discusses possible mechanisms involved in the process of breathlessness reduction through pharmacotherapy. Research gaps in the field of persistent breathlessness research are outlined, and future research directions are suggested.

EXPERT OPINION

Regular, low-dose (≤30 mg/day), sustained-release morphine is recommended as the first-line pharmacological treatment for persistent breathlessness. Inter-individual variation in response needs to be investigated in future studies in order to optimize clinical outcomes. This includes 1) better understanding the centrally mediated mechanisms associated with persisting breathlessness and response to pharmacological therapies, 2) understanding benefit from the perspective of people experiencing persistent breathlessness, small and meaningful gains in physical activity.

Differential control of respiratory frequency and tidal volume during exercise

The lack of a testable model explaining how ventilation is regulated in different exercise conditions has been repeatedly acknowledged in the field of exercise physiology. Yet, this issue contrasts with the abundance of insightful findings produced over the last century and calls for the adoption of new integrative perspectives. In this review, we provide a methodological approach supporting the importance of producing a set of evidence by evaluating different studies together-especially those conducted in 'real' exercise conditions-instead of single studies separately. We show how the collective assessment of findings from three domains and three levels of observation support the development of a simple model of ventilatory control which proves to be effective in different exercise protocols, populations and experimental interventions. The main feature of the model is the differential control of respiratory frequency (f_R) and tidal volume (V_T); f_R is primarily modulated by central command (especially during high-intensity exercise) and muscle afferent feedback (especially during moderate exercise) whereas V_T by metabolic inputs. Furthermore, V_T appears to be fine-tuned based on f_R levels to match alveolar ventilation with metabolic requirements in different intensity domains, and even at a breath-by-breath level. This model reconciles the classical neuro-humoral theory with apparently contrasting findings by leveraging on the emerging control properties of the behavioural (i.e. f_R) and metabolic (i.e. V_T) components of minute ventilation. The integrative approach presented is expected to help in the design and interpretation of future studies on the control of f_R and V_T during exercise.

Opioid Prescription Method for Breathlessness Due to Non-Cancer Chronic Respiratory Diseases: A Systematic Review

A previous pooled analysis demonstrated significant relief of breathlessness following opioid administration in patients with chronic obstructive pulmonary disease. However, in clinical practice, it is important to know the characteristics of patients responding to opioids, the best prescription methods, and the evaluation measures that can sufficiently reflect these effects. Thus, we performed a systematic review of systemic opioids for non-cancer chronic respiratory diseases. Fifteen randomized controlled studies (RCTs), four non-randomized studies, two observational studies, and five retrospective studies were included. Recent RCTs suggested that regular oral opioid use would decrease the worst breathlessness in patients with a modified Medical Research Council score ≥ 3 by a degree of 1.0 or less on a scale of 1–10. Ergometer or treadmill tests indicated mostly consistent significant acute effects of morphine or codeine. In two non-randomized studies, about 60% of patients responded to opioids and showed definite improvement in symptoms and quality of life. Furthermore, titration of opioids in these studies suggested that a major proportion of these responders had benefits after administration of approximately 10 mg/day of morphine. However, more studies are needed to clarify the prescription method to reduce withdrawal due to adverse effects, which would lead to significant improvements in overall well-being.

Dyspnea

The clinical term dyspnea (a.k.a. breathlessness or shortness of breath) encompasses at least three qualitatively distinct sensations that warn of threats to breathing: air hunger, effort to breathe, and chest tightness. Air hunger is a primal homeostatic warning signal of insufficient alveolar ventilation that can produce fear and anxiety and severely impacts the lives of patients with cardiopulmonary, neuromuscular, psychological, and end-stage disease. The sense of effort to breathe informs of increased respiratory muscle activity and warns of potential impediments to breathing. Most frequently associated with bronchoconstriction, chest tightness may warn of airway inflammation and constriction through activation of airway sensory nerves. This chapter reviews human and functional brain imaging studies with comparison to pertinent neurorespiratory studies in animals to propose the interoceptive networks underlying each sensation. The neural origins of their distinct sensory and affective dimensions are discussed, and areas for future research are proposed. Despite dyspnea's clinical prevalence and impact, management of dyspnea languishes decades behind the treatment of pain. The neurophysiological bases of current therapeutic approaches are reviewed; however, a better understanding of the neural mechanisms of dyspnea may lead to development of novel therapies and improved patient care.

A critical review of the respiratory benefits and harms of orally administered opioids for dyspnea management in COPD

INTRODUCTION

Dyspnea occurring in chronic obstructive pulmonary disease (COPD) that is refractory to traditional management strategies is a common and challenging problem. Considerable attention has been paid to the off-label use of orally administered opioids as a pharmacotherapy option for refractory dyspnea in COPD. Multiple professional respiratory society guidelines express support for the application of oral opioids for this purpose.

AREAS COVERED

This manuscript will critically review randomized controlled trials undertaken to date that evaluate the efficacy of oral opioids for dyspnea in COPD, as well as phase IV observational studies that examine for potential opioid-related respiratory harms in the COPD population (literature was searched on PubMed up to June 2021). COPD guideline recommendations relating to opioids for dyspnea will subsequently be critiqued.

EXPERT OPINION

Opioid efficacy trials demonstrate at best a small improvement in dyspnea in limited numbers of individuals with COPD, whereas safety trials consistently show an increased risk of respiratory-related exacerbation, hospitalization and death in association with opioid use. In contrast to what is expressed in guidelines, the current body of evidence does not the support the wide application of opioids to manage refractory dyspnea among individuals with COPD, but instead, a highly selective and careful approach.

Opioids in patients with COPD and refractory dyspnea: literature review and design of a multicenter double blind study of low dosed morphine and fentanyl (MoreFoRCOPD)

Background

Refractory dyspnea or breathlessness is a common symptom in patients with advanced chronic obstructive pulmonary disease (COPD), with a high negative impact on quality of life (QoL). Low dosed opioids have been investigated for refractory dyspnea in COPD and other life-limiting conditions, and some positive effects were demonstrated. However, upon first assessment of the literature, the quality of evidence in COPD seemed low or inconclusive, and focused mainly on morphine which may have more side effects than other opioids such as fentanyl. For the current publication we performed a systematic literature search. We searched for placebo-controlled randomized clinical trials investigating opioids for refractory dyspnea caused by COPD. We included trials reporting on dyspnea, health status and/or QoL. Three of fifteen trials demonstrated a significant positive effect of opioids on dyspnea. Only one of four trials reporting on QoL or health status, demonstrated a significant positive effect. Two-thirds of included trials investigated morphine. We found no placebo-controlled RCT on transdermal fentanyl. Subsequently, we hypothesized that both fentanyl and morphine provide a greater reduction of dyspnea than placebo, and that fentanyl has less side effects than morphine.

Methods

We describe the design of a robust, multi-center, double blind, double-dummy, cross-over, randomized, placebo-controlled clinical trial with three study arms investigating transdermal fentanyl 12 mcg/h and morphine sustained-release 10 mg b.i.d. The primary endpoint is change in daily mean dyspnea sensation measured on a numeric rating scale. Secondary endpoints are change in daily worst dyspnea, QoL, anxiety, sleep quality, hypercapnia, side effects, patient preference, and continued opioid use. Sixty patients with severe stable COPD and refractory dyspnea (FEV₁ < 50%, mMRC ≥ 3, on optimal standard therapy) will be included.

Discussion

Evidence for opioids for refractory dyspnea in COPD is not as robust as usually appreciated. We designed a study comparing both the more commonly used opioid morphine, and transdermal fentanyl to placebo. The cross-over design will help to get a better impression of patient preferences. We believe our study design to investigate both sustained-release morphine and transdermal fentanyl for refractory dyspnea will provide valuable information for better treatment of refractory dyspnea in COPD.

Trial registration NCT03834363 (ClinicalTrials.gov), registred at 7 Feb 2019, https://clinicaltrials.gov/ct2/show/NCT03834363.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01647-8.

Benefits, for patients with late stage chronic obstructive pulmonary disease, of being cared for in specialized palliative care compared to hospital. A nationwide register study

BACKGROUND

In early stage chronic obstructive pulmonary disease (COPD), dyspnea has been reported as the main symptom; but at the end of life, patients dying from COPD have a heavy symptom burden. Still, specialist palliative care is seldom offered to patients with COPD; they more often receive end of life care in hospitals. Furthermore, symptoms, symptom relief and care activities in the last week of life for COPD patients are rarely studied. The aim of this study was to compare patient and care characteristics in late stage COPD patients treated in specialized palliative care (SPC) versus hospital.

METHODS

Two nationwide registers were merged, the Swedish National Airway Register (SNAR) and the Swedish Register of Palliative Care (SRPC). Patients with COPD and < 50% of predicted forced expiratory volume in 1 s (FEV1), who had died in inpatient or outpatient SPC (n = 159) or in hospital (n = 439), were identified. Clinical COPD characteristics were extracted from the SNAR, and end of life (EOL) care characteristics from the SRPC. Descriptive statistics were used to describe the sample and the registered care and treatments. Independent samples t-test, Mantel-Haenszel chi-square test and Fisher's exact test was used to compare variables. To examine predictors of place of death, bivariate and multivariate logistic regression analyses were performed with a dependent variable with demographic and clinical variables used as independent variables.

RESULTS

The patients in hospitals were older and more likely to have heart failure or hypertension. Pain was more frequently reported and relieved in SPC than in hospitals (p = 0.001). Rattle, anxiety, delirium and nausea were reported at similar frequencies between the settings; but rattle, anxiety, delirium, and dyspnea were more frequently relieved in SPC (all p < 0.001). Compared to hospital, SPC was more often the preferred place of care (p < 0.001). In SPC, EOL discussions with patients and families were more frequently held than in hospital (p < 0.001). Heart failure increased the probability of dying in hospital while lung cancer increased the probability of dying in SPC.

CONCLUSION

This study provides evidence for referring more COPD patients to SPC, which is more focused on symptom management and psychosocial and existential support.

Predictors of Opioid-related Adverse Pulmonary Events among Older Adults with Chronic Obstructive Pulmonary Disease

Rationale: Although opioids are frequently prescribed in chronic obstructive pulmonary disease (COPD), there is poor understanding regarding which individuals will experience pulmonary harm upon exposure.Objectives: We sought to identify patient characteristics and opioid drug properties predictive of opioid-related adverse pulmonary events among older adults with chronic COPD.Methods: A retrospective, population-based, cohort study design was used, analyzing Ontario heath administrative data. Individuals aged 66 years and older, with validated, physician-diagnosed COPD receiving a new opioid drug were included. Adverse pulmonary events (defined as an emergency room visit, hospitalization, or death related to either COPD or pneumonia) occurring within 30 days following new opioid receipt were considered. Multivariable-adjusted, cause-specific hazard modeling was used to identify predictors of adverse pulmonary events.Results: Out of 169,517 older adults with COPD receiving a new opioid, 4,861 (2.9%) experienced an adverse pulmonary event within 30 days. Factors independently predisposing to adverse pulmonary events included older age (≥85 yr old: hazard ratio [HR], 1.37; 95% confidence interval [CI], 1.26-1.49), long-term-care home residence (HR, 1.32; 95% CI, 1.21-1.44), severe COPD exacerbation within the preceding year (HR, 2.96; 95% CI, 2.77-3.17), comorbidities (including non-COPD lung disease [HR, 1.16; 95% CI, 1.09-1.23], congestive heart failure [HR, 1.22; 95% CI, 1.14-1.30], sleep disorder [HR, 1.22; 95% CI, 1.15-1.30], and dementia [HR, 1.14; 95% CI, 1.05-1.24]); other psychoactive medication receipt, including benzodiazepines (HR, 1.27; 95% CI, 1.19-1.35) and serotonergic antidepressants (HR, 1.10; 95% CI, 1.03-1.19), and receipt of an opioid-only agent (HR, 1.35; 95% CI, 1.26-1.46). Factors that independently protected from adverse pulmonary events included female sex (HR, 0.78; 95% CI, 0.73-0.82), surgery within the preceding year (HR, 0.70; 95% CI, 0.64-0.77), and musculoskeletal disease (HR, 0.75; 95% CI, 0.70-0.80). No significant associations were observed between adverse pulmonary events and opioid half-life duration or opioid daily dosage.Conclusions: Patient and opioid drug factors predictive of opioid-related adverse pulmonary events among older adults with COPD were identified, which may assist with safer opioid prescribing.

How to Assess Breathlessness in Chronic Obstructive Pulmonary Disease

Activity-related breathlessness is the most problematic symptom of chronic obstructive pulmonary disease (COPD), arising from complex interactions between peripheral pathophysiology (both pulmonary and non-pulmonary) and central perceptual processing. To capture information on the breathlessness experienced by people with COPD, many different instruments exist, which vary in applicability depending on the purpose and context of assessment. We reviewed common breathlessness assessment instruments, providing recommendations around how to assess the severity of, or change in, breathlessness in people with COPD in daily life or in response to exercise provocation. A summary of 14 instruments for the assessment of breathlessness severity in daily life is presented, with 11/14 (79%) instruments having established minimal clinically importance differences (MCIDs) to assess and interpret breathlessness change. Instruments varied in their scope of assessment (functional impact of breathlessness or the severity of breathlessness during different activities, focal periods, or alongside other common COPD symptoms), dimensions of breathlessness assessed (uni-/multidimensional), rating scale properties and intended method of administration (self-administered versus interviewer led). Assessing breathlessness in response to an acute exercise provocation overcomes some limitations of daily life assessment, such as recall bias and lack of standardized exertional stimulus. To assess the severity of breathlessness in response to an acute exercise provocation, unidimensional or multidimensional instruments are available. Borg's 0-10 category rating scale is the most widely used instrument and has estimates for a MCID during exercise. When assessing the severity of breathlessness during exercise, measures should be taken at a standardized submaximal point, whether during laboratory-based tests like cardiopulmonary exercise testing or field-based tests, such as the 3-min constant rate stair stepping or shuttle walking tests. Recommendations are provided around which instruments to use for breathlessness assessment in daily life and in relation to exertion in people with COPD.

Research and Healthcare Priorities of Individuals Living with COPD

This study describes the research and healthcare priorities of individuals living with COPD. On an online survey, individuals living with COPD assigned a percentage of funding to 22 research priorities and a percentage of time spent communicating with a healthcare provider to 24 healthcare priorities, indicating which topics were most important. For each research and healthcare priority, we examined the selection frequency of the priority and used chi-square analyses to examine differences in priority selection by quartiles of airflow obstruction (percent predicted forced expiratory volume in 1-sec (FEV₁%predicted)) and breathlessness burden and exacerbation risk. Based on participants' responses (N = 148, 47% women; Mean ± Standard Deviation age = 68 ± 9 yrs) relief of breathlessness was the most often selected research (76% of respondents) and healthcare priority (61% of respondents). It was selected most often, regardless of disease severity or breathlessness burden and exacerbation risk. We found differences for disease severity and breathlessness burden and exacerbation risk in some research priorities (e.g., to improve the maximal amount of exercise of adults living with COPD in and out of the home (χ²₍₃₎ = 9.97, Cramer's V =.28) and healthcare priorities (e.g., increase your ability to exercise (χ²₍₃₎ = 9.72, Cramer's V =.27)). This study provides empirical evidence that relief of breathlessness is a top research and healthcare priority for individuals living with COPD. Future healthcare and research activities should align with the priorities of individuals with COPD to improve their care by minimizing disease/symptom burden and optimizing health-related quality of life.

High-Flow Nasal Cannula Therapy for Exertional Dyspnea in Patients with Cancer: A Pilot Randomized Clinical Trial

BACKGROUND

Exertional dyspnea is common in patients with cancer and limits their function. The impact of high-flow nasal cannula on exertional dyspnea in nonhypoxemic patients is unclear. In this double-blind, parallel-group, randomized trial, we assessed the effect of flow rate (high vs. low) and gas (oxygen vs. air) on exertional dyspnea in nonhypoxemic patients with cancer.

PATIENTS AND METHODS

Patients with cancer with oxygen saturation >90% at rest and exertion completed incremental and constant work (80% maximal) cycle ergometry while breathing low-flow air at 2 L/minute. They were then randomized to receive high-flow oxygen, high-flow air, low-flow oxygen, or low-flow air while performing symptom-limited endurance cycle ergometry at 80% maximal. The primary outcome was modified 0-10 Borg dyspnea intensity scale at isotime. Secondary outcomes included dyspnea unpleasantness, exercise time, and adverse events.

RESULTS

Seventy-four patients were enrolled, and 44 completed the study (mean age 63; 41% female). Compared with low-flow air at baseline, dyspnea intensity was significantly lower at isotime with high-flow oxygen (mean change, -1.1; 95% confidence interval [CI], -2.1, -0.12) and low-flow oxygen (-1.83; 95% CI, -2.7, -0.9), but not high-flow air (-0.2; 95% CI, -0.97, 0.6) or low-flow air (-0.5; 95% CI, -1.3, 0.4). Compared with low-flow air, high-flow oxygen also resulted in significantly longer exercise time (difference + 2.5 minutes, p = .009), but not low-flow oxygen (+0.39 minutes, p = .65) or high-flow air (+0.63 minutes, p = .48). The interventions were well tolerated without significant adverse effects.

CONCLUSION

Our preliminary findings support that high-flow oxygen improved both exertional dyspnea and exercise duration in nonhypoxemic patients with cancer. (ClinicalTrials.gov ID: NCT02357134).

IMPLICATIONS FOR PRACTICE

In this four-arm, double-blind, randomized clinical trial examining the role of high-flow nasal cannula on exertional dyspnea in patients with cancer without hypoxemia, high-flow oxygen, but not high-flow air, resulted in significantly lower dyspnea scores and longer exercise time. High-flow oxygen delivered by high-flow nasal cannula devices may improve clinically relevant outcomes even in patients without hypoxemia.

Pulmonary Rehabilitation

Pulmonary rehabilitation (PR) is an essential intervention in the management of patients with chronic obstructive pulmonary disease. To guide health care professionals in the implementation and evaluation of a PR program, this article discusses the current key concepts regarding exercise testing, prescription, and training, as well as self-management intervention as essential parts of PR and post-rehabilitation maintenance. Moreover, new approaches (alternative forms of organization and delivery, tele-rehabilitation, exercise adjuncts) and unique and challenging situations (patients experiencing acute exacerbations, advanced disease) are thoroughly reviewed. Finally, validated point-of-care resources and online tools are provided.

Clinical Utility of Measuring Inspiratory Neural Drive During Cardiopulmonary Exercise Testing (CPET)

Cardiopulmonary exercise testing (CPET) has traditionally included ventilatory and metabolic measurements alongside electrocardiographic characterization; however, research increasingly acknowledges the utility of also measuring inspiratory neural drive (IND) through its surrogate measure of diaphragmatic electromyography (EMGdi). While true IND also encompasses the activation of non-diaphragmatic respiratory muscles, the current review focuses on diaphragmatic measurements, providing information about additional inspiratory muscle groups for context where appropriate. Evaluation of IND provides mechanistic insight into the origins of dyspnea and exercise limitation across pathologies; yields valuable information reflecting the integration of diverse mechanical, chemical, locomotor, and metabolic afferent signals; and can help assess the efficacy of therapeutic interventions. Further, IND measurement during the physiologic stress of exercise is uniquely poised to reveal the underpinnings of physiologic limitations masked during resting and unloaded breathing, with important information provided not only at peak exercise, but throughout exercise protocols. As our understanding of IND presentation across varying conditions continues to grow and methods for its measurement become more accessible, the translation of these principles into clinical settings is a logical next step in facilitating appropriate and nuanced management tailored to each individual's unique physiology. This review provides an overview of the current state of understanding of IND measurement during CPET: its origins, known patterns of behavior and links with dyspnea in health and major respiratory diseases, and the possibility of expanding this approach to applications beyond exercise.

Managing Severe Chronic Breathlessness in Chronic Obstructive Pulmonary Disease Is Challenging for General Practitioners

CONTEXT

Patients with advanced chronic obstructive pulmonary disease (COPD) can develop increasing breathlessness, which can persist despite optimal medical management-refractory breathlessness. Management can be challenging for all clinicians and requires a broad approach that includes optimization of disease directed therapies, non-pharmacological strategies to manage breathlessness and for some patients opioids.

OBJECTIVES

To explore the approaches to breathlessness management and palliative care undertaken by Australian General Practitioners (GP) for patients with severe COPD and refractory breathlessness.

METHODS

A case-vignette based survey was conducted with Australian GPs to determine their approaches to breathlessness management and palliative care in COPD.

RESULTS

Of the 137 GPs, 66% recommended commencing an additional medication to manage refractory breathlessness. Thirty-eight GPs (28%) recommended opioids and 26 (19%) recommended guideline discordant treatments. Two-thirds of GPs had concerns regarding the use of opioids in COPD. Half (55%) of GPs were comfortable providing general palliative care to patients with COPD and 62 (45%) had referred patients with COPD to specialist palliative care services. Most respondents wanted further training to manage severe COPD and severe chronic breathlessness.

CONCLUSION

Most GPs recognized and were willing to add specific treatments for severe chronic breathlessness. However, experience prescribing opioids for severe chronic breathlessness was low, with many practitioners holding significant concerns regarding adverse effects. Many GPs are uncomfortable offering a palliative approach to their COPD patients, yet these patients are not routinely referred to specialist palliative care services despite their immense needs. GPs therefore desire education and support to overcome these barriers.

Standardized measurement of breathlessness during exercise

PURPOSE OF REVIEW

Exertional breathlessness is common and pervasive across various chronic disease populations. To accurately assess response to intervention and optimize clinical (symptom) management, detailed assessment of exertional breathlessness is imperative. This review provides an update on current approaches to assess exertional breathlessness and presents the need for individualized assessment of breathlessness standardized for the level of exertion.

RECENT FINDINGS

Breathlessness assessment tools commonly invite people to recall their breathlessness while at rest with reference to activities of daily living. To directly quantify breathlessness, however, requires assessment of the dimensions of breathlessness (e.g., sensory intensity, quality, and unpleasantness) in response to a standardized exercise stimulus. Different exercise stimuli (e.g., self-paced, incremental, and constant work rate exercise tests) have been used to elicit a breathlessness response. Self-paced (e.g., 6-min walk test) and incremental exercise tests assess exercise tolerance or endurance, and are not recommended for assessment of exertional breathlessness. Constant work rate tests, however, including recently validated 3-min constant-rate stair stepping and walking tests, standardize the exercise stimulus to enable the breathlessness response to be directly quantified and monitored over time.

SUMMARY

To adequately guide symptom management and assess intervention efficacy, clinicians and researchers should assess breathlessness with multidimensional assessment tools in response to a standardized and individualized exercise stimulus.

Why treatment efficacy on breathlessness in laboratory but not daily life trials? The importance of standardized exertion

PURPOSE OF REVIEW

Treatments for chronic breathlessness, including opioids and oxygen, have shown efficacy in the controlled laboratory setting, whereas effects have been inconsistent or absent in trials in daily life. This review discusses the lack of standardized exertion as a potential cause of false negative findings for breathlessness in daily life.

RECENT FINDINGS

The level of breathlessness can be modified by patients by changing their level of physical activity. Effects of opioids and oxygen have been shown at standardized level of exertion (iso-time) but not at the end of symptom-limited (peak) exertion. Trials in daily life reporting no effects on breathlessness did not standardize the exertion or employed insensitive methods, such as the 6-min walk test that should not be used for measuring breathlessness. Novel tests - the 3-min walk and stepping tests have been validated in chronic obstructive pulmonary disease and are responsive for measuring change in breathlessness.

SUMMARY

Breathlessness should be measured at standardized exertion, otherwise treatment effects may be biased or overlooked. Tests for valid measurement of breathlessness in clinical practice and daily life are available and emerging.

Use of short-acting opioids in the management of breathlessness: an evidence-based review

PURPOSE OF REVIEW

To provide an evidence-based review on the use of short-acting opioids for management of breathlessness in patients with advanced diseases.

RECENT FINDINGS

We identified 28 randomized controlled trials that examined the effect of short-acting opioids on breathlessness under three study settings: as a prophylactic dose given prior to exertion; as a rescue dose for treatment of breathlessness at rest or episodic breathlessness; or as a scheduled medication for overall reduction of breathlessness. These trials varied widely in regard to patient population (opioid naive or tolerant), opioid (formulation, dose, timing of administration, and scheduling) and control intervention. Taken together, there is good evidence to support that short-acting opioids can reduce breathlessness and improve activity level when given before exertion. There is some evidence that parenteral opioids are efficacious for the as needed treatment of episodic breathlessness or breathlessness at rest. However, there is only limited evidence to support scheduled short-acting opioids for overall relief of breathlessness.

SUMMARY

There is evidence to support that short-acting opioids have a pharmacologic effect on breathlessness. More research is needed to clarify how opioids can be prescribed to optimize breathlessness relief, function, and quality of life.

Experimental dyspnoea interferes with locomotion and cognition: a randomised trial

BACKGROUND

Chronic respiratory diseases are associated with cognitive dysfunction, but whether dyspnoea by itself negatively impacts on cognition has not been demonstrated. Cortical networks engaged in subjects experiencing dyspnoea are also activated during other tasks that require cognitive input and this may provoke a negative impact through interference with each other.

METHODS

This randomised, crossover trial investigated whether experimentally-induced dyspnoea would negatively impact on locomotion and cognitive function among 40 healthy adults. Crossover conditions were unloaded breathing or loaded breathing using an inspiratory threshold load. To evaluate locomotion, participants were assessed by the Timed Up and Go (TUG) test. Cognitive function was assessed by categorical and phonemic verbal fluency tests, the Trail Making Tests (TMTs) A and B (executive function), the CODE test from the Wechsler Adult Intelligence Scale (WAIS)-IV (processing speed) and by direct and indirect digit span (working memory).

RESULTS

The mean time difference to perform the TUG test between unloaded and loaded breathing was -0.752 s (95% CI -1.012 to -0.492 s) (p<0.001). Executive function, processing speed and working memory performed better during unloaded breathing, particularly for subjects starting first with the loaded breathing condition.

CONCLUSION

Our data suggest that respiratory threshold loading to elicit dyspnoea had a major impact on locomotion and cognitive function in healthy adults.

Dyspnea in COPD: New Mechanistic Insights and Management Implications

Dyspnea is the most common symptom experienced by patients with chronic obstructive pulmonary disease (COPD). To avoid exertional dyspnea, many patients adopt a sedentary lifestyle which predictably leads to extensive skeletal muscle deconditioning, social isolation, and its negative psychological sequalae. This "dyspnea spiral" is well documented and it is no surprise that alleviation of this distressing symptom has become a key objective highlighted across COPD guidelines. In reality, this important goal is often difficult to achieve, and successful symptom management awaits a clearer understanding of the underlying mechanisms of dyspnea and how these can be therapeutically manipulated for the patients' benefit. Current theoretical constructs of the origins of activity-related dyspnea generally endorse the classical demand-capacity imbalance theory. Thus, it is believed that disruption of the normally harmonious relationship between inspiratory neural drive (IND) to breathe and the simultaneous dynamic response of the respiratory system fundamentally shapes the expression of respiratory discomfort in COPD. Sadly, the symptom of dyspnea cannot be eliminated in patients with advanced COPD with relatively fixed pathophysiological impairment. However, there is evidence that effective symptom palliation is possible for many. Interventions that reduce IND, without compromising alveolar ventilation (VA), or that improve respiratory mechanics and muscle function, or that address the affective dimension, achieve measurable benefits. A common final pathway of dyspnea relief and improved exercise tolerance across the range of therapeutic interventions (bronchodilators, exercise training, ambulatory oxygen, inspiratory muscle training, and opiate medications) is reduced neuromechanical dissociation of the respiratory system. These interventions, singly and in combination, partially restore more harmonious matching of excessive IND to ventilatory output achieved. In this review we propose, on the basis of a thorough review of the recent literature, that effective dyspnea amelioration requires combined interventions and a structured multidisciplinary approach, carefully tailored to meet the specific needs of the individual.

Effect of Vaporized Cannabis on Exertional Breathlessness and Exercise Endurance in Advanced Chronic Obstructive Pulmonary Disease. A Randomized Controlled Trial

RATIONALE

A series of studies conducted approximately 40 years ago demonstrated an acute bronchodilator effect of smoked cannabis in healthy adults and adults with asthma. However, the acute effects of vaporized cannabis on airway function in adults with advanced chronic obstructive pulmonary disease (COPD) remain unknown.

OBJECTIVES

To test the hypothesis that inhaled vaporized cannabis would alleviate exertional breathlessness and improve exercise endurance by enhancing static and dynamic airway function in COPD.

METHODS

In a randomized controlled trial of 16 adults with advanced COPD (forced expiratory volume in 1 second [FEV₁], mean ± SD: 36 ± 11% predicted), we compared the acute effect of 35 mg of inhaled vaporized cannabis (18.2% Δ⁹-tetrahydrocannabinol, <0.1% cannabidiol) versus 35 mg of a placebo control cannabis (CTRL; 0.33% Δ⁹-tetrahydrocannabinol, <0.99% cannabidiol) on physiological and perceptual responses during cardiopulmonary cycle endurance exercise testing; spirometry and impulse oscillometry at rest; and cognitive function, psychoactivity, and mood.

RESULTS

Compared with CTRL, cannabis had no effect on breathlessness intensity ratings during exercise at isotime (cannabis, 2.7 ± 1.2 Borg units vs. CTRL, 2.6 ± 1.3 Borg units); exercise endurance time (cannabis, 3.8 ± 1.9 min vs. CTRL, 4.2 ± 1.9 min); cardiac, metabolic, gas exchange, ventilatory, breathing pattern, and/or operating lung volume parameters at rest and during exercise; spirometry and impulse oscillometry-derived pulmonary function test parameters at rest; and cognitive function, psychoactivity, and mood.

CONCLUSIONS

Single-dose inhalation of vaporized cannabis had no clinically meaningful positive or negative effect on airway function, exertional breathlessness, and exercise endurance in adults with advanced COPD. Clinical trial registered with www.clinicaltrials.gov (NCT03060993).

Physiological and perceptual responses to exercise according to locus of symptom limitation in COPD

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease, with pulmonary and extra-pulmonary factors contributing to exercise intolerance. The primary self-reported exercise-limiting symptom may reflect the primary pathophysiological factor contributing to exercise intolerance. We compared physiological and perceptual responses at the symptom-limited peak of incremental cardiopulmonary cycle exercise testing between people with COPD reporting breathlessness (B, n = 34), leg discomfort (LD, n = 16), or a combination of B and LD (BOTH, n = 42) as their main exercise-limiting symptom(s). Despite similarly impaired health status, symptomology and peak exercise capacity, the B group had greater restrictive constraints on tidal volume expansion at end-exercise and was more likely to report unpleasant qualities of exertional breathlessness than LD and BOTH groups. In conclusion, reporting breathlessness as the primary exercise-limiting symptom indicated the presence of distinct lung pathophysiology and symptom perception during exercise in people with COPD.

Isolating peripheral effects of endogenous opioids in modulating exertional breathlessness in people with moderate or severe COPD: a randomised controlled trial

QUESTION ADDRESSED BY THE STUDY

Endogenous opioids (endorphins) have been reported to modulate exercise-induced breathlessness, but the relative contribution of peripheral opioid receptors has not been tested.

MATERIALS PARTICIPANTS AND METHODS

This was a double-blind, randomised, three-arm, cross-over trial in outpatients with spirometry-verified moderate to severe chronic obstructive pulmonary disease. Participants undertook an incremental symptom-limited treadmill test followed by five endurance treadmill tests at 75% of their maximal work rate; two tests for familiarisation and three tests 30 min after intravenous injection of either methylnaltrexone 0.3 mg·kg-1 (blocking peripheral opioid receptors only) or naloxone 0.1 mg·kg-1 (blocking both central and peripheral opioid receptors) or normal saline, in randomised order. The primary end-point was the regression slope between breathlessness intensity (0-10 numerical rating scale) and oxygen consumption (V'O2 ) during the walk tests, comparing methylnaltrexone and placebo using a paired t-test.

RESULTS

17 participants completed the trial: median (range) 66 (55-82) years; 15 males; mean±sd forced expiratory volume (FEV1) 53.8±17.6% predicted; FEV1/forced vital capacity ratio 0.55±15.9. There was no statistically or clinically significant difference in the primary end-point (regression slope of breathlessness intensity and V'O2 ) for methylnaltrexone (p=0.498) or naloxone (p=0.804), compared to placebo. Secondary outcomes were similar between the three treatment groups, including peak and mean breathlessness intensity and unpleasantness, exercise capacity, endurance time and leg fatigue.

ANSWER TO THE QUESTION

Blocking peripheral opioid receptors (methylnaltrexone) or peripheral and central opioid receptors (naloxone) did not appear to modulate breathlessness intensity nor exercise capacity when compared with placebo (no blockade).

Opioids for breathlessness: psychological and neural factors influencing response variability

Chronic breathlessness is a multidimensional and aversive symptom, which is often poorly explained by underlying pathophysiology [1]. For many sufferers, breathlessness is refractory to maximal medical therapies that target disease processes [2]. However, opioids are thought to be a possible therapeutic avenue to treat symptomology independently of disease [3]. Importantly, research in chronic pain has demonstrated that qualities such as anxiety and depression (collectively termed negative affect here) can both exacerbate symptoms [4] and reduce opioid efficacy [5, 6]. Therefore, it may be pertinent to consider such behavioural factors when contemplating the use of opioids for breathlessness.

Diminished opioid efficacy in the treatment of breathlessness is related to negative affect and anticipatory brain activity in the anterior cingulate and medial prefrontal cortex.http://bit.ly/2LXyyDo

Differences between experienced and recalled breathlessness: a review

PURPOSE OF REVIEW

Experienced breathlessness and recalled breathlessness are two different entities, which may be associated with different factors and might have different impacts on function for the individual. The aim was to review the knowledge from the last 2 years concerning experienced breathlessness and recalled breathlessness and related factors.

RECENT FINDINGS

Experienced breathlessness was most often induced or measured during exercise testing in a lab environment using a modified Borg scale. It was associated with both psychological factors, such as social rejection, presence of others, psychosocial stress and prenatal exposure to stress, as well as physical factors, such as hypoxia and frequent exacerbations.Recalled breathlessness was most often measured in epidemiological studies, most commonly using the modified Medical Research Council scale. It was associated with lung volumes, overweight, exercise training, frailty, smoking, personality traits, behavior and marital and occupational status.

SUMMARY

No studies during the review period had directly compared experienced breathlessness and recalled breathlessness. Several factors were related to either experienced breathlessness or recalled breathlessness but no clear differences between factors were found in this review. There is a need for comparative studies using the same measurement methods and in the same settings in order to examine their relation.

Updates in opioid and nonopioid treatment for chronic breathlessness

PURPOSE OF REVIEW

Chronic breathlessness is a troublesome symptom experienced by people with advanced malignant and nonmalignant disease. Disease-directed therapies are often insufficient in the management of chronic breathlessness. Therefore, pharmacological and nonpharmacological breathlessness-specific interventions should be considered for select patients.

RECENT FINDINGS

There is some evidence to support the use of low-dose opioids (≤30 mg morphine equivalents per day) for the relief of breathlessness in the short term. However, additional studies are needed to understand the efficacy of opioids for chronic breathlessness in the long term.Nonopioid therapies, including inspiratory muscle training, fan-to-face therapy, L-menthol and inhaled nebulized furosemide show some promise for the relief of breathlessness in advanced disease. There is insufficient evidence to support the use of anxiolytics and benzodiazepines and cannabis for chronic breathlessness.

SUMMARY

More research is needed to identify therapies for the management of chronic breathlessness.

Extended-Release Morphine for Chronic Breathlessness in Pulmonary Arterial Hypertension-A Randomized, Double-Blind, Placebo-Controlled, Crossover Study

CONTEXT

Pulmonary arterial hypertension (PAH) affects people of all ages and is associated with poor prognosis. Chronic breathlessness affects almost all people with PAH.

OBJECTIVES

This randomized, placebo-controlled, double-blind, crossover study aimed to evaluate the effects of regular, low-dose, extended-release (ER) morphine for PAH-associated chronic breathlessness.

METHODS

Participants with PAH-associated chronic breathlessness were randomized to 1) seven days of ER morphine 20 mg, 2) seven-day washout, and 3) seven days of identically looking placebo, or vice versa. Primary end points were breathlessness "right now"-morning and evening-measured with a Visual Analogue Scale. Secondary end points included additional breathlessness measures, quality of life, function, harms, and blinded treatment preference (ACTRN12609000209291).

RESULTS

Within a period of seven years, 50 patients were assessed in detail and 23 (46%) were randomized (despite broad eligibility criteria). Four participants withdrew while taking morphine. Nineteen participants completed the study. Breathlessness "right now" was higher on morphine compared with placebo both for morning [mean (M) ± SD 31.7 ± 25 mm vs. 26.9 ± 22 mm; effect size (80% CI) = -0.22 (-0.6 to 0.2)] and evening [(M ± SD 33.5 ± 28 mm vs. 25.6 ± 21 mm; effect size (80% CI) = -0.33 (-0.8 to 0.1)]. All secondary measures of breathlessness were higher with morphine as were nausea and constipation.

CONCLUSION

This study does not support a Phase III study of ER morphine for people with PAH-associated chronic breathlessness. Recruiting to the target sample size was difficult, the direction of effect in every measure of breathlessness favored placebo and morphine generated more harms.

Differing Approaches to Managing the Chronic Breathlessness Syndrome in Advanced COPD: A Multi-National Survey of Specialists

This study explored the approaches of respiratory and palliative medicine specialists to managing the chronic breathlessness syndrome in patients with severe chronic obstructive pulmonary disease. A voluntary, online survey was emailed to all specialists and trainees in respiratory medicine in Australia and New Zealand (ANZ), and to all palliative medicine specialists and trainees in ANZ and the United Kingdom (UK). Five hundred and seventy-seven (33.0%) responses were received from 1,749 specialists, with 440 (25.2%) complete questionnaires included from 177 respiratory and 263 palliative medicine doctors. Palliative medicine doctors in ANZ and the UK had similar approaches to managing chronic breathlessness, whereas respiratory and palliative medicine doctors had significantly different approaches (p < 0.0001). Both specialties most commonly recommended a combination of non-pharmacological and pharmacological breathlessness management strategies. Respiratory doctors focussed more on pulmonary rehabilitation, whereas palliative medicine doctors recommended breathing techniques, anxiety management and the handheld fan. Palliative medicine doctors (197 (74.9%)) recommended short acting oral morphine for breathlessness, as compared with 73 (41.2%) respiratory doctors (p < 0.0001). Respiratory doctors cited opioid concerns related to respiratory depression and lack of knowledge. Nineteen (10.7%) respiratory doctors made no specific recommendations for managing chronic breathlessness. Both specialties reported actively managing chronic breathlessness, albeit with differing approaches. Integrated services, which combine the complementary knowledge and approaches of both specialities, may overcome current gaps in care and improve the management of distressing, chronic breathlessness.