Chronic breathlessness: re-thinking the symptom

Explain Breathlessness: Could 'Usual' Explanations Contribute to Maladaptive Beliefs of People Living with Breathlessness?

BACKGROUND

Explanations provided by healthcare professionals contribute to patient beliefs. Little is known about how healthcare professionals explain chronic breathlessness to people living with this adverse sensation.

METHODS

A purpose-designed survey disseminated via newsletters of Australian professional associations (physiotherapy, respiratory medicine, palliative care). Respondents provided free-text responses for their usual explanation and concepts important to include, avoid, or perceived as difficult to understand by recipients. Content analysis coded free text into mutually exclusive categories with the proportion of respondents in each category reported.

RESULTS

Respondents (n = 61) were predominantly clinicians (93%) who frequently (80% daily/weekly) conversed with patients about breathlessness. Frequent phrases included within usual explanations reflected breathlessness resulting from medical conditions (70% of respondents) and physiological mechanisms (44%) with foci ranging from multifactorial to single-mechanism origins. Management principles were important to include and phrases encouraging maladaptive beliefs were important to avoid. The most frequent difficult concept identified concerned inconsistent relationships between oxygenation and breathlessness. Where explanations included the term 'oxygen', a form of cognitive shortcut (heuristic) may contribute to erroneous beliefs.

CONCLUSIONS

This study presents examples of health professional explanations for chronic breathlessness as a starting point for considering whether and how explanations could contribute to adaptive or maladaptive breathlessness beliefs of recipients.

Post-COVID breathlessness: a mathematical model of respiratory processing in the brain

Breathlessness is among the most common post-COVID symptoms. In a considerable number of patients, severe breathlessness cannot be explained by peripheral organ impairment. Recent concepts have described how such persistent breathlessness could arise from dysfunctional processing of respiratory information in the brain. In this paper, we present a first quantitative and testable mathematical model of how processing of respiratory-related signals could lead to breathlessness perception. The model is based on recent theories that the brain holds an adaptive and dynamic internal representation of a respiratory state that is based on previous experiences and comprises gas exchange between environment, lung and tissue cells. Perceived breathlessness reflects the brain's estimate of this respiratory state signaling a potentially hazardous disequilibrium in gas exchange. The internal respiratory state evolves from the respiratory state of the last breath, is updated by a sensory measurement of CO2 concentration, and is dependent on the current activity context. To evaluate our model and thus test the assumed mechanism, we used data from an ongoing rebreathing experiment investigating breathlessness in patients with post-COVID without peripheral organ dysfunction (N = 5) and healthy control participants without complaints after COVID-19 (N = 5). Although the observed breathlessness patterns varied extensively between individual participants in the rebreathing experiment, our model shows good performance in replicating these individual, heterogeneous time courses. The model assumes the same underlying processes in the central nervous system in all individuals, i.e., also between patients and healthy control participants, and we hypothesize that differences in breathlessness are explained by different weighting and thus influence of these processes on the final percept. Our model could thus be applied in future studies to provide insight into where in the processing cascade of respiratory signals a deficit is located that leads to (post-COVID) breathlessness. A potential clinical application could be, e.g., the monitoring of effects of pulmonary rehabilitation on respiratory processing in the brain to improve the therapeutic strategies.

Puzzled by dysfunctional breathing disorder(s)? Consider the Bayesian brain hypothesis!

There is currently growing clinical concern regarding dysfunctional breathing disorder(s) (DBD), an umbrella term for a set of multidimensional clinical conditions that are characterized by altered breathing pattern associated with a variety of intermittent or chronic symptoms, notably dyspnea, in the absence or in excess of, organic disease. However, several aspects of DBD remain poorly understood and/or open to debate, especially the inconsistent relationship between the array of experienced symptoms and their supposedly underlying mechanisms. This may be partly due to a more general problem, i.e., the prevailing way we conceptualize symptoms. In the present article, after a brief review of the different aspects of DBD from the current perspective, I submit a call for considering DBD under the innovating perspective of the Bayesian brain hypothesis, i.e., a potent and novel model that fundamentally changes our views on symptom perception.

Breathlessness in a virtual world: An experimental paradigm testing how discrepancy between VR visual gradients and pedal resistance during stationary cycling affects breathlessness perception

INTRODUCTION

The sensation of breathlessness is often attributed to perturbations in cardio-pulmonary physiology, leading to changes in afferent signals. New evidence suggests that these signals are interpreted in the light of prior "expectations". A misalignment between afferent signals and expectations may underly unexplained breathlessness. Using a novel immersive virtual reality (VR) exercise paradigm, we investigated whether manipulating an individual's expectation of effort (determined by a virtual hill gradient) may alter their perception of breathlessness, independent from actual effort (the physical effort of cycling).

METHODS

Nineteen healthy volunteers completed a single experimental session where they exercised on a cycle ergometer while wearing a VR headset. We created an immersive virtual cycle ride where participants climbed up 100 m hills with virtual gradients of 4%, 6%, 8%, 10% and 12%. Each virtual hill gradient was completed twice: once with a 4% cycling ergometer resistance and once with a 6% resistance, allowing us to dissociate expected effort (virtual hill gradient) from actual effort (power). At the end of each hill, participants reported their perceived breathlessness. Linear mixed effects models were used to examine the independent contribution of actual effort and expected effort to ratings of breathlessness (0-10 scale).

RESULTS

Expectation of effort (effect estimate ± std. error, 0.63 ± 0.11, P < 0.001) and actual effort (0.81 ± 0.21, P < 0.001) independently explained subjective ratings of breathlessness, with comparable contributions of 19% and 18%, respectively. Additionally, we found that effort expectation accounted for 6% of participants' power and was a significant, independent predictor (0.09 ± 0.03; P = 0.001).

CONCLUSIONS

An individuals' expectation of effort is equally important for forming perceptions of breathlessness as the actual effort required to cycle. A new VR paradigm enables this to be experimentally studied and could be used to re-align breathlessness and enhance training programmes.

Breathing control, brain, and bodily self-consciousness: Toward immersive digiceuticals to alleviate respiratory suffering

Breathing is peculiar among autonomic functions through several characteristics. It generates a very rich afferent traffic from an array of structures belonging to the respiratory system to various areas of the brain. It is intimately associated with bodily movements. It bears particular relationships with consciousness as its efferent motor control can be automatic or voluntary. In this review within the scope of "respiratory neurophysiology" or "respiratory neuroscience", we describe the physiological organisation of breathing control. We then review findings linking breathing and bodily self-consciousness through respiratory manipulations using virtual reality (VR). After discussing the currently admitted neurophysiological model for dyspnea, as well as a new Bayesian model applied to breathing control, we propose that visuo-respiratory paradigms -as developed in cognitive neuroscience- will foster insights into some of the basic mechanisms of the human respiratory system and will also lead to the development of immersive VR-based digital health tools (i.e. digiceuticals).

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.

Objects of safety and imprisonment: Breathless patients' use of medical objects in a palliative setting

In this article, the authors consider breathless adults with advanced non-malignant lung disease and their relationship with health objects. This issue is especially relevant now during the Covid-19 pandemic, where the experiences of breathlessness and dependence on related medical objects have sudden and global relevance. These objects include ambulatory oxygen, oxygen concentrators and inhalers, and non-pharmacological objects such as self-monitoring devices and self-management technologies. The authors consider this relationship between things and people using an interdisciplinary approach employing psychoanalytic theory (in particular Winnicott's theory of object relations and object use), Science and Technology Studies (STS) and phenomenology. This collaborative approach allows them to relate patient use of health objects to ways of thinking about the body, dependency, autonomy, safety and sense-making within the context of palliative care. The authors illustrate the theoretical discussion with three reflective vignettes from therapeutic practice and conclude by suggesting further interdisciplinary research to develop the conceptual and practice-based links between psychoanalytic theory, STS and phenomenology to better understand individual embodied experiences of breathlessness. They call for palliative care-infused, psychoanalytically informed interventions that acknowledge breathless patients' dependence on things and people, concomitant with the need for autonomy in being-towards-dying.

Bearing witness to the challenges of breathlessness

The community respiratory nurse specialist (CRNS) supports patients at different stages of lung disease, witnessing the challenge of living with chronic obstructive pulmonary disease (COPD), a progressive illness for which there is no cure. Breathlessness is the most prominent and debilitating symptom experienced; it is frightening, distressing and very difficult to manage. Little is known about the experience of CRNSs in witnessing the distress of patients, specifically those experiencing breathlessness. The nurse may have cared for such patients over many months or years. In witnessing this distress, CRNSs engage in emotional labour, which is associated with burnout and poor-quality care. This paper seeks to identify bearing witness to suffering and vulnerability as components of emotional labour in the context of the CRNS role. It highlights the need for research to explore the experience of CRNSs and insights into supporting people with long-term breathlessness. It is more likely that well-supported staff can provide sustained, supportive care to patients living with breathlessness.

Multidimensional breathlessness response to exercise: Impact of COPD and healthy ageing

This study compared the multidimensional breathlessness response to incremental cardiopulmonary cycle exercise testing (CPET) in people with chronic obstructive pulmonary disease (COPD; n = 14, aged 69 ± 9 years, forced expiratory volume in 1-sec = 54 ± 16 % predicted) and healthy older (OA) (n = 35, aged 68 ± 5 years) and younger (YA) (n = 19, aged 28 ± 8 years) adults. Participants performed CPET and successively rated overall breathlessness intensity, unsatisfied inspiration, breathing too shallow, work/effort of breathing, and breathlessness-related unpleasantness, fear, and anxiety using the 0-10 Borg scale. At any given percent predicted peak minute ventilation, people with COPD rated all breathlessness sensations higher than OA and YAs, who were similar. Most between group differences disappeared when examined in relation to inspiratory reserve volume, except people with COPD reported higher levels of unsatisfied inspiration and breathing too shallow (vs YA), and breathlessness-related fear and anxiety (vs OA and YAs). Multidimensional ratings of breathlessness sensations during CPET provides further insight into differences in exertional symptom perceptions among people with COPD and without COPD.

Taking Charge: A Proposed Psychological Intervention to Improve Pulmonary Rehabilitation Outcomes for People with COPD

Pulmonary rehabilitation (PR) is an important, evidence-based treatment that improves outcomes for people with COPD. Individualized exercise programmes aim to improve exercise capacity; self-management education and psychological support are also provided. Translating increased exercise capacity into sustained behavioural change of increased physical activity is difficult. Other unresolved problems with PR programmes include improving uptake, completion, response and sustaining long-term benefit. We offer a different perspective drawn from clinical experience of PR, quantitative and qualitative studies of singing groups for people with COPD, and stroke rehabilitation research that gives psychological factors a more central role in determining outcomes after PR. We discuss Take Charge; a simple but effective psychological intervention promoting self-management--that could be used as part of a PR programme or in situations where PR was declined or unavailable. This may be particularly relevant now when traditional face-to-face group programmes have been disrupted by COVID-19 precautions.

En Pointe: Dancers Report Their Pain Less Variably Than Do Controls

The subjective nature of pain and the lack of a gold standard for objective measurement hinders effective assessment, diagnosis, and treatment. Some individuals, such as professional dancers, are better in assessing and reporting bodily sensations. This observational study aimed to assess whether dancers report their pain less variably, than other people do. After consenting, subjects completed the focused analgesia selection test (FAST), which assesses subjects' variability of pain reports. FAST outcomes, ICC and R² reflect the magnitude of variability of pain reports observed. In addition, subjects underwent a taste task, which similarly assesses variability of tastes (salty and sweet) intensity reports and completed the Multidimensional Assessment of Interoceptive Awareness questionnaire. Thirty-three professional dancers and 33 healthy aged-matched controls were recruited. The dancers exhibited less variability of pain reports then controls (P = .013), but not in case of tastes-reports. Years of practice was positively correlated with pain reporting variability (r = .447, P = .009, and r = .380, P = .029; for FAST ICC and R², respectively). Multidimensional Assessment of Interoceptive Awareness subscores correlated with pain reporting variability: R² and ICC with emotional awareness (r = .260, P = .040, and r = .274, P = .030, respectively), and R² with trusting [r = .254, P = .044]). PERSPECTIVE: The difference between dancers and controls in the magnitude of variability of pain reports is probably due to the dancers' extensive training, which focuses on attention to body signals. Our results suggest that training can improve subjective pain reports, which are essential for quality clinical care.

Disrupted breath, songlines of breathlessness: an interdisciplinary response

Health research is often bounded by disciplinary expertise. While cross-disciplinary collaborations are often forged, the analysis of data which draws on more than one discipline at the same time is underexplored. Life of Breath, a 5-year project funded by the Wellcome Trust to understand the clinical, historical and cultural phenomenology of the breath and breathlessness, brings together an interdisciplinary team, including medical humanities scholars, respiratory clinicians, medical anthropologists, medical historians, cultural theorists, artists and philosophers. While individual members of the Life of Breath team come together to share ongoing work, collaborate and learn from each other's approach, we also had the ambition to explore the feasibility of integrating our approaches in a shared response to the same piece of textual data. In this article, we present our pluralistic, interdisciplinary analysis of an excerpt from a single cognitive interview transcript with a patient with chronic obstructive pulmonary disease. We discuss the variation in the responses and interpretations of the data, why research into breathlessness may particularly benefit from an interdisciplinary approach, and the wider implications of the findings for interdisciplinary research within health and medicine.

Improving the quality of life of people with advanced respiratory disease and severe breathlessness

Advanced respiratory disease imposes a greater symptom burden than many cancers but not does have comparable recognition of the need for supportive and palliative care or the infrastructure for its systematic delivery. Consequently, many people with advanced respiratory disease (and those closest to them) have a poor quality of life, disabled by chronic breathlessness, fatigue and other symptoms. They are socially isolated by the consequences of long-term illness and are often financially impoverished. The past decade has seen an increasing realisation that care for this group must improve and that symptom management must be prioritised. Clinical guidelines recommend person-centred care, including access to supportive and palliative care as needed, as part of standard medical practice. Advanced lung disease clinics and specialist breathlessness services (pioneered within palliative care) are developing within respiratory medicine services but are provided inconsistently. This review covers the comprehensive assessment of the patient with advanced respiratory disease, the importance of supporting carers and the current best practice in the management of breathlessness, fatigue and cough. It also suggests ways to incorporate person-centred care into the general respiratory clinic, assisted by better liaison with specialist palliative and primary care. Emerging evidence shows that excellent symptom management leads to better clinical outcomes and reduces inappropriate use of emergency medical services.

KEY POINTS

People living with advanced respiratory disease and severe chronic breathlessness (and those closest to them) have a poor quality of life.Chronic breathlessness is a disabling symptom, and acute-on-chronic/episodic breathlessness is frightening to experience and observe.Chronic breathlessness imposes profound physical limitations and psychosocial burdens on those suffering from it or living with someone experiencing it.Fatigue and cough are two other cardinal symptoms of advanced respiratory disease, with very detrimental effects on quality of life.The impact of all these symptoms can be alleviated to a variable extent by a predominantly non-drug complex intervention.Many of the interventions are delivered primarily by allied health or nursing professionals.Doctors, nurses and other health professionals also need to play an active part in promoting quality of life as part of excellent medical care.A person-centred, psychologically informed approach is needed by all clinicians treating patients with advanced respiratory disease.

EDUCATIONAL AIMS

To give specialist respiratory clinicians practical clinical tools to help improve the quality of life of their patients with advanced respiratory disease and chronic breathlessness.To outline the evidence base for these interventions with reference to definitive sources.To highlight the importance of person-centred care in people with respiratory disease at all stages of illness.