Inhaled furosemide for relief of air hunger versus sense of breathing effort: a randomized controlled trial

Medical hypnosis mitigates laboratory dyspnoea in healthy humans: a randomised, controlled experimental trial

QUESTION

Dyspnoea persisting despite treatments of underlying causes requires symptomatic approaches. Medical hypnosis could provide relief without the untoward effects of pharmacological approaches. We addressed this question through experimentally induced dyspnoea in healthy humans (inspiratory threshold loading (excessive inspiratory effort) and carbon dioxide stimulation (air hunger)).

MATERIAL AND METHODS

20 volunteers (10 women, aged 21-40 years) were studied on four separate days. The order of the visits was randomised in two steps: firstly, the "inspiratory threshold loading first" versus "carbon dioxide first" group (n=10 in each group); secondly, the "medical hypnosis first" versus "visual distraction first" subgroup (n=5 in each subgroup). Each visit comprised three 5-min periods (reference, intervention, washout) during which participants used visual analogue scales (VAS) to rate the sensory and affective dimensions of dyspnoea, and after which they completed the Multidimensional Dyspnea Profile.

RESULTS

Medical hypnosis reduced both dimensions of dyspnoea significantly more than visual distraction (inspiratory threshold loading: sensory reduction after 5 min 34% of full VAS versus 8% (p=0.0042), affective reduction 17.6% versus 2.4% (p=0.044); carbon dioxide: sensory reduction after 5 min 36.9% versus 3% (p=0.0015), affective reduction 29.1% versus 8.7% (p=0.0023)). The Multidimensional Dyspnea Profile showed more marked sensory effects during inspiratory threshold loading and more marked affective effects during carbon dioxide stimulation.

ANSWER TO THE QUESTION

Medical hypnosis was more effective than visual distraction at attenuating the sensory and affective dimensions of experimentally induced dyspnoea. This provides a strong rationale for clinical studies of hypnosis in persistent dyspnoea patients.

Blunted perception of breathlessness in three cases of low grade insular-glioma

Better understanding of breathlessness perception addresses an unmet clinical need for more effective treatments for intractable dyspnoea, a prevalent symptom of multiple medical conditions. The insular-cortex is predominantly activated in brain-imaging studies of dyspnoea, but its precise role remains unclear. We measured experimentally-induced hypercapnic air-hunger in three insular-glioma patients before and after surgical resection. Tests involved one-minute increments in inspired CO2, raising end-tidal PCO2 to 7.5 mmHg above baseline (38.5 ± 5.7 mmHg), whilst ventilation was constrained (10.7 ± 2.3 L/min). Patients rated air-hunger on a visual analogue scale (VAS). Patients had lower stimulus-response (2.8 ± 2 vs. 11 ± 4 %VAS/mmHg; p = 0.004), but similar threshold (40.5 ± 3.9 vs. 43.2 ± 5.1 mmHg), compared to healthy individuals. Volunteered comments implicated diminished affective valence. After surgical resection; sensitivity increased in one patient, decreased in another, and other was unable to tolerate the ventilatory limit before any increase in inspired CO2.We suggest that functional insular-cortex is essential to register breathlessness unpleasantness and could be targeted with neuromodulation in chronically-breathless patients. Neurological patients with insula involvement should be monitored for blunted breathlessness to inform clinical management.

Nebulized Furosemide for Pulmonary Inflammation in Intubated Patients With COVID-19: A Phase 2 Randomized Controlled Double-Blind Study

OBJECTIVES

Respiratory failure secondary to COVID-19 is associated with morbidity and mortality. Current anti-inflammatory therapies are effective but are given systemically and have significant side effects. Furosemide has anti-inflammatory properties, can be administered by inhalation, and is inexpensive. We investigated the efficacy of nebulized furosemide as an adjunctive therapy for COVID-19 respiratory failure.

DESIGN

A double-blind, randomized, placebo-controlled trial.

SETTING

Multicenter ICU study.

PATIENTS

Adults requiring invasive mechanical ventilation secondary to COVID-19.

INTERVENTION

Patients were randomized within 48 hours of intubation to receive inhaled furosemide or placebo until day 28, death, or liberation from mechanical ventilation.

MEASUREMENTS AND MAIN RESULTS

The study was stopped early due to waning incidence of COVID-19; 39 patients were available for analysis with mean ± sd age of 70.5 (10.8) years, Acute Physiology and Chronic Health Evaluation II 26.1 (7.8) and Fio2 60.0% (21.9). Baseline characteristics were similar between the groups. For the primary outcome of change in Pao2/Fio2 ratio between day 1 and day 6, it was +31.4 (83.5) in the furosemide arm versus +20.1 (92.8) in the control (p = 0.58). For secondary outcomes, furosemide versus control: 60-day mortality was 48% versus 71% (p = 0.20), hospital stay was 25.6 (21.9) versus 27.4 (25.0) days, p = 0.94 and VFD was 6.0 (9.1) versus 3.1 (7.1), p value of equals to 0.28. A post hoc analysis of the hierarchical composite outcome, alive and ventilator-free favored furosemide. There were no adverse events.

CONCLUSIONS

In this trial of inhaled furosemide for COVID-19 respiratory failure, differences in Pao2/Fio2 ratio to day 6 and other clinical outcomes were not significantly different, although the trial was underpowered due to early termination. Given the favorable profile of inhaled furosemide, further study is warranted in disease states where acute pulmonary inflammation contributes to the underlying pathophysiology.

Nebulised furosemide for the treatment of patients with obstructive lung disease: a systematic review protocol

INTRODUCTION

Obstructive lung diseases (OLDs) such as asthma and chronic obstructive pulmonary disease are major global sources of morbidity and mortality. Current treatments broadly include bronchodilators such as beta agonists/antimuscarinics and anti-inflammatory agents such as steroids. Despite therapy patients still experience exacerbations of their diseases and overall decline over time. Nebulised furosemide may have a novel use in the treatment of OLD. Multiple small studies have shown improvement in pulmonary function as well as dyspnoea. This systematic review will aim to summarise and analyse the existing literature on nebulised furosemide use in OLD to guide treatment and future studies.

METHODS AND ANALYSIS

We will identify all experimental studies using nebulised/inhaled furosemide in patients with asthma or chronic obstructive pulmonary disease that report any outcome. Databases will include EMBASE, MEDLINE, Cochrane Database of Systematic Reviews, ACP Journal Club, Database of Abstracts of Reviews of Effects, Cochrane Clinical Answers, Cochrane Central Register of Controlled Trials, Cochrane Methodology Register, Health Technology Assessment and the NHS Economic Evaluation Database (1995-2015). We will also search ClinicalTrials.gov and the WHO-International Clinical Trials Registry Platform. Two reviewers will independently determine trial eligibility. For each included trial, we will perform duplicate independent data extraction, risk of bias assessment and evaluation of the quality of evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.

ETHICS AND DISSEMINATION

Ethical approval will not be applicable to this systematic review. The results of the study will be communicated through publication in peer-reviewed journals.

PROSPERO REGISTRATION NUMBER

CRD42021284680.

Optimal Management of Heart Failure and Chronic Obstructive Pulmonary Disease: Clinical Challenges

Heart failure (HF) and chronic obstructive pulmonary disease (COPD) are common causes of breathlessness which frequently co-exist; one potentially exacerbating the other. Distinguishing between the two can be challenging due to their similar symptomatology and overlapping risk factors, but a timely and correct diagnosis is potentially lifesaving. Modern treatment for HF can substantially improve symptoms and prognosis for many patients and may have beneficial effects for patients with COPD. Conversely, while many inhaled treatments for COPD can improve symptoms and reduce exacerbations, there is conflicting evidence regarding the safety of some inhaled treatments for COPD in patients with HF. Here we explore the overlap between HF and COPD, examine the effect of one condition on the other, and address the challenges of managing patients with both conditions.

Effects of inhaled furosemide on dyspnea and pulmonary function in people with COPD: A literature review

PURPOSE

To determine whether inhaled furosemide can be effectively used in patients with chronic obstructive pulmonary disease (COPD) to improve feelings of dyspnea and improve pulmonary function values.

METHODS

This literature review was conducted using randomized control trials and a literature review in which the participants consisted of or included patients with COPD receiving inhaled furosemide as a potential treatment option for their dyspnea and low pulmonary function values.

RESULTS

Searches in four databases and secondary sources using five key terms yielded 83 unduplicated articles. Ultimately, four studies, one of which was a literature review, were included which studied the short-term result of inhaled furosemide on dyspnea and pulmonary function values. All studies measured dyspnea as an outcome and three found a statistically significant improvement in patient reported symptoms. Pulmonary function values were measured in all studies which all found improvements.

CONCLUSION

The effect of inhaled furosemide on the dyspnea and pulmonary function values in people with COPD remains uncertain, and questions have emerged regarding the long-term impact on these patients. While this therapy is promising for dyspnea relief and improvement of pulmonary function values in people with COPD, further consideration and additional data still need to be gathered.

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).

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.

Pharmacologic and Non-Pharmacologic Dyspnea Management in Advanced Cancer Patients

As there is a high propensity for patients with advanced malignancy to experience refractory dyspnea, it is necessary for physicians to be well-versed in the management of these patients' dyspneic symptoms. For symptomatic treatment of cancer patients with dyspnea, both pharmacologic and non-pharmacologic methods should be considered. The main source of pharmacologic symptom management for dyspnea is oral and parenteral opioids; benzodiazepines and corticosteroids may serve as helpful adjuncts alongside opioid treatments. However, oxygen administration and nebulized loop diuretics have not been shown to clinically benefit dyspneic cancer patients. Applying non-pharmacologic dyspnea management methods may be valuable palliative therapies for advanced cancer patients, as they provide benefit with negligible harm to the patient. Advantageous and minimally harmful non-pharmacologic dyspnea therapies include facial airflow, acupuncture and/or acupressure, breathing exercises, cognitive behavioral therapy, music therapy, and spiritual interventions. Thus, it is vital that physicians are prepared to provide symptomatic care for dyspnea in advanced cancer patients as to minimize suffering in this patient population during definitive cancer treatments or hospice care.

Inhalation Delivery for the Treatment and Prevention of COVID-19 Infection

Coronavirus disease-2019 (COVID-19) is caused by coronavirus-2 (SARS-CoV-2) and has produced a global pandemic. As of 22 June 2021, 178 million people have been affected worldwide, and 3.87 million people have died from COVID-19. According to the Centers for Disease Control and Prevention (CDC) of the United States, COVID-19 virus is primarily transmitted between people through respiratory droplets and contact routes. Since the location of initial infection and disease progression is primarily through the lungs, the inhalation delivery of drugs directly to the lungs may be the most appropriate route of administration for treating COVID-19. This review article aims to present possible inhalation therapeutics and vaccines for the treatment of COVID-19 symptoms. This review covers the comparison between SARS-CoV-2 and other coronaviruses such as SARS-CoV/MERS, inhalation therapeutics for the treatment of COVID-19 symptoms, and vaccines for preventing infection, as well as the current clinical status of inhaled therapeutics and vaccines.

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.

Pharmacotherapeutic principles of fluid management in heart failure

Introduction: Heart failure is a major public health concern that is expected to increase over the decades to come. Despite significant advances, fluid overload and congestion remain a major therapeutic challenge. Vascular congestion and neurohormonal activation are intricately linked and the goal of therapy fundamentally aims to reduce both.Areas covered: The authors briefly review a number of core concepts that elucidate the link between fluid overload and neuro-hormonal activation. This is followed by a review of heart-kidney interactions and the impact of diuresis in this setting. Following an in-depth review of currently available pharmacological agents, the rationale and evidence behind their use, the authors end with a brief note on novel agents/approaches to aid volume management in HF.Expert opinion: A number of non-pharmacological advances in the management of volume overload in heart failure, though promising - are associated with a number of shortcomings. Pharmacological therapy remains the cornerstone of volume management. A number of novel approaches, utilizing existing therapies as well as the emergence of new agents over the past decade bode well for the vulnerable HF population.

Small molecule therapeutics for COVID-19: repurposing of inhaled furosemide

The novel coronavirus SARS-CoV-2 has become a global health concern. The morbidity and mortality of the potentially lethal infection caused by this virus arise from the initial viral infection and the subsequent host inflammatory response. The latter may lead to excessive release of pro-inflammatory cytokines, IL-6 and IL-8, as well as TNF-α ultimately culminating in hypercytokinemia (“cytokine storm”). To address this immuno-inflammatory pathogenesis, multiple clinical trials have been proposed to evaluate anti-inflammatory biologic therapies targeting specific cytokines. However, despite the obvious clinical utility of such biologics, their specific applicability to COVID-19 has multiple drawbacks, including they target only one of the multiple cytokines involved in COVID-19’s immunopathy. Therefore, we set out to identify a small molecule with broad-spectrum anti-inflammatory mechanism of action targeting multiple cytokines of innate immunity. In this study, a library of small molecules endogenous to the human body was assembled, subjected to in silico molecular docking simulations and a focused in vitro screen to identify anti-pro-inflammatory activity via interleukin inhibition. This has enabled us to identify the loop diuretic furosemide as a candidate molecule. To pre-clinically evaluate furosemide as a putative COVID-19 therapeutic, we studied its anti-inflammatory activity on RAW264.7, THP-1 and SIM-A9 cell lines stimulated by lipopolysaccharide (LPS). Upon treatment with furosemide, LPS-induced production of pro-inflammatory cytokines was reduced, indicating that furosemide suppresses the M1 polarization, including IL-6 and TNF-α release. In addition, we found that furosemide promotes the production of anti-inflammatory cytokine products (IL-1RA, arginase), indicating M2 polarization. Accordingly, we conclude that furosemide is a reasonably potent inhibitor of IL-6 and TNF-α that is also safe, inexpensive and well-studied. Our pre-clinical data suggest that it may be a candidate for repurposing as an inhaled therapy against COVID-19.

Is Inhaled Furosemide a Potential Therapeutic for COVID-19?

The potentially lethal infection caused by the novel Severe Acute Respiratory Disease Coronavirus-2 (SARS-CoV-2) has evolved into a global crisis. Following the initial viral infection is the host inflammatory response that frequently results in excessive secretion of inflammatory cytokines (e.g., IL-6 and TNFα), developing into a self-targeting, toxic "cytokine storm" causing critical pulmonary tissue damage. The need for a therapeutic that is available immediately is growing daily but the de novo development of a vaccine may take years. Therefore, repurposing of approved drugs offers a promising approach to address this urgent need. Inhaled furosemide, a small molecule capable of inhibiting IL-6 and TNFα, may be an agent capable of treating the Coronavirus Disease 2019 cytokine storm in both resource-rich and developing countries. Furosemide is a "repurpose-able" small molecule therapeutics, that is safe, easily synthesized, handled, and stored, and is available in reasonable quantities worldwide.

Controlled Delivery of 80 mg Aerosol Furosemide Does Not Achieve Consistent Dyspnea Relief in Patients

PURPOSE

Aerosol furosemide may be an option to treat refractory dyspnea, though doses, methods of delivery, and outcomes have been variable. We hypothesized that controlled delivery of high dose aerosol furosemide would reduce variability of dyspnea relief in patients with underlying pulmonary disease.

METHODS

Seventeen patients with chronic exertional dyspnea were recruited. Patients rated recently recalled breathing discomfort on a numerical rating scale (NRS) and the multidimensional dyspnea profile (MDP). They then performed graded exercise using an arm-ergometer. The NRS was completed following each exercise grade, and the MDP was repeated after a pre-defined dyspnea threshold was reached. During separate visits, patients received either aerosol saline or 80 mg of aerosol furosemide in a randomized, double-blind, crossover design. After treatment, graded exercise to the pre-treatment level was repeated, followed by completion of the NRS and MDP. Treatment effect was defined as the difference between pre- and post-treatment NRS at end exercise, expressed in absolute terms as % Full Scale. "Responders" were defined as those showing treatment effect ≥ 20% of full scale.

RESULTS

Final analysis included 15 patients. Neither treatment produced a statistically significant change in NRS and there was no significant difference between treatments (p = 0.45). There were four "responders" and one patient whose dyspnea worsened with furosemide; two patients were responders with saline, of whom one also responded to furosemide. No adverse events were reported.

CONCLUSIONS

High dose controlled delivery aerosol furosemide was not statistically different from saline placebo at reducing exercise-induced dyspnea. However, a clinically meaningful improvement was noted in some patients.

Non-linear regulation of cardiac autonomic modulation in obese youths: interpolation of ultra-short time series

BACKGROUND

In this study, we applied ultra-short time series of interbeat intervals (RR-intervals) to evaluate heart rate variability through default chaotic global techniques with the purpose of discriminating obese youths from non-obese youth patients.

METHOD

Chaotic global analysis of the RR-intervals from the electrocardiogram and pre-processing adjustments was undertaken. The effect of cubic spline interpolations was assessed, while the spectral parameters remained fixed. Exactly, 125 RR-intervals of data were recorded.

RESULTS

CFP1, CFP3, and CFP6 were the only significant combinations of chaotic globals when the standard conditions were enforced and at the level p<0.01 (or <1%). These significances were acheived via Kruskal-Wallis and Cohen's ds effects sizes tests of significance after Anderson-Darling and Lilliefors statistical tests indicated non-normal distributions in the majority of cases. Adjustments of the cubic spline interpolation from 1 to 13 Hz were revealed to be inconsequential when measured by Kruskal-Wallis and Cohen's ds, regarding the outcome between the two datasets.

CONCLUSION

Chaotic global analysis was offered as a robust technique to distinguish autonomic dysfunction in obese youths. It can discriminate the two different groups using ultra-short data lengths, and no cubic spline interpolations need be applied.

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.

Strategies to relieve dyspnoea in patients with advanced chronic respiratory diseases. A narrative review

BACKGROUND AND OBJECTIVE

The management of symptoms in patients with advanced chronic respiratory diseases needs more attention. This review summarizes the latest evidence on interventions to relieve dyspnoea in these patients.

METHODS

We searched randomised controlled trials, observational studies, systematic reviews, and meta-analyses published between 1990 and 2019 in English in PubMed data base using the keywords. Dyspnoea, Breathlessness AND: pharmacological and non pharmacological therapy, oxygen, non invasive ventilation, pulmonary rehabilitation, alternative medicine, intensive care, palliative care, integrated care, self-management. Studies on drugs (e.g. bronchodilators) or interventions (e.g. lung volume reduction surgery, lung transplantation) to manage underlying conditions and complications, or tools for relief of associated symptoms such as pain, are not addressed.

RESULTS

Relief of dyspnoea has received relatively little attention in clinical practice and literature. Many pharmacological and non pharmacological therapies are available to relieve dyspnoea, and improve patients' quality of life. There is a need for greater knowledge of the benefits and risks of these tools by doctors, patients and families to avoid unnecessary fears which might reduce or delay the delivery of appropriate care. We need services for multidisciplinary care in early and late phases of diseases. Early integration of palliative care with respiratory, primary care, and rehabilitation services can help patients and caregivers.

CONCLUSION

Relief of dyspnoea as well as of any distressing symptom is a human right and an ethical duty for doctors and caregivers who have many potential resources to achieve this.