Relieving dyspnoea by non-invasive ventilation decreases pain thresholds in amyotrophic lateral sclerosis

Dyspnoea-12 and Multidimensional Dyspnea Profile: Systematic Review of Use and Properties

CONTEXT

The Dyspnoea-12 (D-12) and Multidimensional Dyspnea Profile (MDP) were specifically developed for assessment of multiple sensations of breathlessness.

OBJECTIVES

This systematic review aimed to identify the use and measurement properties of the D-12 and MDP across populations, settings and languages.

METHODS

Electronic databases were searched for primary studies (2008-2020) reporting use of the D-12 or MDP in adults. Two independent reviewers completed screening and data extraction. Study and participant characteristics, instrument use, reported scores and minimal clinical important differences (MCID) were evaluated. Data on internal consistency (Cronbach's α) and test-retest reliability (intraclass correlation coefficient, ICC) were pooled using random effects models between settings and languages.

RESULTS

A total 75 publications reported use of D-12 (n = 35), MDP (n = 37) or both (n = 3), reflecting 16 chronic conditions. Synthesis confirmed two factor structure, internal consistency (Cronbach's α mean, 95% CI: D-12 Total = 0.93, 0.91-0.94; MDP Immediate Perception [IP] = 0.88, 0.85-0.90; MDP Emotional Response [ER] = 0.86, 0.82-0.89) and 14 day test-rest reliability (ICC: D-12 Total = 0.91, 0.88-0.94; MDP IP = 0.85, 0.70-0.93; MDP ER = 0.84, 0.73-0.90) across settings and languages. MCID estimates for clinical interventions ranged between -3 and -6 points (D-12 Total) with small variability in scores over 2 weeks (D-12 Total 2.8 (95% CI: 2.0 to 3.7), MDP-A1 0.8 (0.6 to 1.1) and six months (D-12 Total 2.9 (2.0 to 3.7), MDP-A1 0.8 (0.6 to 1.1)).

CONCLUSION

D-12 and MDP are widely used, reliable, valid and responsive across various chronic conditions, settings and languages, and could be considered standard instruments for measuring dimensions of breathlessness in international trials.

Air Hunger: A Primal Sensation and a Primary Element of Dyspnea

The sensation that develops as a long breath hold continues is what this article is about. We term this sensation of an urge to breathe "air hunger." Air hunger, a primal sensation, alerts us to a failure to meet an urgent homeostatic need maintaining gas exchange. Anxiety, frustration, and fear evoked by air hunger motivate behavioral actions to address the failure. The unpleasantness and emotional consequences of air hunger make it the most debilitating component of clinical dyspnea, a symptom associated with respiratory, cardiovascular, and metabolic diseases. In most clinical populations studied, air hunger is the predominant form of dyspnea (colloquially, shortness of breath). Most experimental subjects can reliably quantify air hunger using rating scales, that is, there is a consistent relationship between stimulus and rating. Stimuli that increase air hunger include hypercapnia, hypoxia, exercise, and acidosis; tidal expansion of the lungs reduces air hunger. Thus, the defining experimental paradigm to evoke air hunger is to elevate the drive to breathe while mechanically restricting ventilation. Functional brain imaging studies have shown that air hunger activates the insular cortex (an integration center for perceptions related to homeostasis, including pain, food hunger, and thirst), as well as limbic structures involved with anxiety and fear. Although much has been learned about air hunger in the past few decades, much remains to be discovered, such as an accepted method to quantify air hunger in nonhuman animals, fundamental questions about neural mechanisms, and adequate and safe methods to mitigate air hunger in clinical situations. © 2021 American Physiological Society. Compr Physiol 11:1449-1483, 2021.

Terminological Usage Related to Dyspnea by Nursing Staff: A Cross-Sectional Questionnaire Survey

In recent years, additional expressions such as 'sensation of breathing discomfort' and 'discomfort of dyspnea' are being used in daily nursing care in Japan. To better understand the current status of the use of these terms by nurses, and to ascertain what the term 'dyspnea' may not express, we designed an original questionnaire and conducted a study with all nurses at our hospital. The questionnaire included questions to determine if nurses used these terms, and in what context. Of the 279 nurses in our hospital, 225 (80.6%) responded. Three-quarters of nurses indicated that they use these terms in clinical nursing practice. There was no difference in the usage of these terms between nurses who had or had not worked in a respiratory outpatients/ward. However, the percentage of nurses using these terms was higher amongst those with 10 years or less nursing experience compared with those with more than 10 years' experience. Open-ended questions revealed that these terms were used to communicate information between nurses and between nurses and patients' families. Our observations need to be verified in large-scale studies to determine if these terms are meaningful for nursing practice in that they describe something not expressed with 'dyspnea'. There is the possibility of confusion due to the use of inappropriate terms and a lack of education on the subject. Many nurses used these terms, and there may be things that the term 'dyspnea' could not express. The results of this study can be used to identify something that is lacking in communication about dyspnea between nurses, nurses and patients, and nurses and patients' families.

Single-inhaler triple therapy in patients with chronic obstructive pulmonary disease: a systematic review

Background

Guidelines recommend that treatment with a long-acting β₂ agonist (LABA), a long-acting muscarinic antagonist (LAMA), and inhaled corticosteroids (ICS), i.e. triple therapy, is reserved for a select group of symptomatic patients with chronic obstructive pulmonary disease (COPD) who continue to exacerbate despite treatment with dual therapy (LABA/LAMA). A number of single-inhaler triple therapies are now available and important clinical questions remain over their role in the patient pathway. We compared the efficacy and safety of single-inhaler triple therapy to assess the magnitude of benefit and to identify patients with the best risk-benefit profile for treatment. We also evaluated and compared study designs and population characteristics to assess the strength of the evidence base.

Methods

We conducted a systematic search, from inception to December 2018, of randomised controlled trials (RCTs) of single-inhaler triple therapy in patients with COPD. The primary outcome was the annual rate of moderate and severe exacerbations.

Results

We identified 523 records, of which 15 reports/abstracts from six RCTs were included. Triple therapy resulted in the reduction of the annual rate of moderate or severe exacerbations in the range of 15–52% compared with LAMA/LABA, 15–35% compared to LABA/ICS and 20% compared to LAMA. The patient-based number needed to treat for the moderate or severe exacerbation outcome ranged between approximately 25–50 (preventing one patient from having an event) and the event-based number needed to treat of around 3–11 (preventing one event). The absolute benefit appeared to be greater in patients with higher eosinophil counts or historical frequency of exacerbations and ex-smokers. In the largest study, there was a significantly higher incidence of pneumonia in the triple therapy arm. There were important differences in study designs and populations impacting the interpretation of the results and indicating there would be significant heterogeneity in cross-trial comparisons.

Conclusion

The decision to prescribe triple therapy should consider patient phenotype, magnitude of benefit and increased risk of adverse events. Future research on specific patient phenotype thresholds that can support treatment and funding decisions is now required from well-designed, robust, clinical trials.

Trial registration

PROSPERO #CRD42018102125.

Highlights from the 2018 European Respiratory Society International Congress: sleep and clinical physiology

The 2018 European Respiratory Society (ERS) International Congress held in Paris, France, served as a platform to discover the latest research on respiratory diseases, the improvement in their treatments and patient care. Specifically, the scientific sessions organised by ERS Assembly 4 provided novel insights into sleep disordered breathing and fresh knowledge in respiratory physiology, stressing its importance to understanding and treating respiratory diseases. This article, divided by session, will summarise the most relevant studies presented at the ERS International Congress. Each session has been written by early career members specialised in the different fields of this interdisciplinary assembly.

NIV in amyotrophic lateral sclerosis: The 'when' and 'how' of the matter

Non-invasive ventilation (NIV) has become an essential part of the treatment of amyotrophic lateral sclerosis (ALS) since 2006. NIV very significantly improves survival, quality of life and cognitive performances. The initial NIV settings are simple, but progression of the disease, ventilator dependence and upper airway involvement sometimes make long-term adjustment of NIV more difficult, with a major impact on survival. Unique data concerning the long-term adjustment of NIV in ALS show that correction of leaks, management of obstructive apnoea and adaptation to the patient's degree of ventilator dependence improve the prognosis. Non-ventilatory factors also impact the efficacy of NIV and various solutions have been described and must be applied, including cough assist techniques, control of excess salivation and renutrition. NIV in ALS has been considerably improved as a result of application of all of these measures, avoiding the need for tracheostomy in the very great majority of cases. More advanced use of NIV also requires pulmonologists to master the associated end-of-life palliative care, as well as the modalities of discontinuing ventilation when it becomes unreasonable.

Long-Term Ventilation in Neuromuscular Patients: Review of Concerns, Beliefs, and Ethical Dilemmas

BACKGROUND

Noninvasive mechanical ventilation (NIV) is an effective treatment in patients with neuromuscular diseases (NMD) to improve symptoms, quality of life, and survival.

SUMMARY

NIV should be used early in the course of respiratory muscle involvement in NMD patients and its requirements may increase over time. Therefore, training on technical equipment at home and advice on problem solving are warranted. Remote monitoring of ventilator parameters using built-in ventilator software is recommended. Telemedicine may be helpful in reducing hospital admissions. Anticipatory planning and palliative care should be carried out to lessen the burden of care, to maintain or withdraw from NIV, and to guarantee the most respectful management in the last days of NMD patients' life. Key Message: Long-term NIV is effective but challenging in NMD patients. Efforts should be made by health care providers in arranging a planned transition to home and end-of-life discussions for ventilator-assisted individuals and their families.

Interferences between breathing, experimental dyspnoea and bodily self-consciousness

Dyspnoea, a subjective experience of breathing discomfort, is a most distressing symptom. It implicates complex cortical networks that partially overlap with those underlying bodily self-consciousness, the experience that the body is one's own within a given location (self-identification and self-location, respectively). Breathing as an interoceptive signal contributes to bodily self-consciousness: we predicted that inducing experimental dyspnoea would modify or disrupt this contribution. We also predicted that manipulating bodily self-consciousness with respiratory-visual stimulation would possibly attenuate dyspnoea. Twenty-five healthy volunteers were exposed to synchronous and asynchronous respiratory-visual illumination of an avatar during normal breathing and mechanically loaded breathing that elicited dyspnoea. During normal breathing, synchronous respiratory-visual stimulation induced illusory self-identification with the avatar and an illusory location of the subjects' breathing towards the avatar. This did not occur when respiratory-visual stimulation was performed during dyspnoea-inducing loaded breathing. In this condition, the affective impact of dyspnoea was attenuated by respiratory-visual stimulation, particularly when asynchronous. This study replicates and reinforces previous studies about the integration of interoceptive and exteroceptive signals in the construction of bodily self-consciousness. It confirms the existence of interferences between experimental dyspnoea and cognitive functions. It suggests that respiratory-visual stimulation should be tested as a non-pharmacological approach of dyspnoea treatment.