Aerosol furosemide for dyspnea: High-dose controlled delivery does not improve effectiveness

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.

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.

Integrating Palliative Care Into Heart Failure Management

BACKGROUND

The World Health Organization defines palliative care as an approach that improves the quality of life of patients and their families through the prevention and relief of suffering by assessment and treatment of physical, psychosocial, and spiritual problems. Any patient with chronic debilitating disease, including heart failure, is a candidate for interdisciplinary palliative care to manage their complex physical and psychosocial needs.

CLINICAL RELEVANCE

The philosophy of palliative care has evolved to include a vision of holistic care extended to all individuals with serious illness and their families or caregivers that should be integrated throughout the continuum of care, including the acute phase. The critical care nurse will likely encounter patients with heart failure who are receiving or are eligible to receive palliative care at various time points during their illness. Critical care nurses therefore play a pivotal role in symptom palliation affecting the heart failure patient's quality of life.

PURPOSE

To review the models of palliative care and the role that the critical care nurse plays in symptom palliation and preparation of the patient and their family for transition to other levels and settings of care.

CONTENT COVERED

This review addresses the principles and models of palliative care along with how to integrate these principles into all phases of the heart failure disease continuum. Also included are recommendations for palliation of symptoms specific to heart failure patients as well as a discussion of the role of the critical care nurse and the importance of shared decision-making.

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.

Efficiency of Nebulizing Furosemide in the Treatment of Chronic Pulmonary Obstructive Disease: A Systematic Review and Meta-Analysis of Clinical Trials

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is one of the most common chronic illnesses in humans. Among both oral and intravenous diuretics, nebulizing furosemide (Lasix) is the most commonly used agent. The purpose of this study was to ascertain the therapeutic effects of nebulizing furosemide compared with placebo in the treatment of COPD using a systematic review and meta-analysis of clinical trials.

MATERIALS AND METHODS

This review was performed based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) protocol. The databases of Web of Science, Google Scholar, PubMed, and Scopus were independently searched by two researchers using MeSH keywords. Studies published between 2002 and 2018 in different parts of the world were considered. The meta-analysis was performed through STATA 14 software and the heterogeneity was assessed using Q statistic or I² index.

RESULTS

From 40 selected articles, 8 articles were finally included in the systematic review process. The analyses were performed considering two groups; nebulizing furosemide treatment (i.e. case) and placebo (i.e. control). Based on the forest plots, the average values of PaCO₂ were 48.3 (39.04-57.56) and 46.56 (39.94-53.18) in the case and control groups, respectively. Also, the mean forced expiratory volume in the first second (FEV1) was 49 (31.32-66.67) and 46.87 (31.44-62.30) in the case and control groups, respectively. Meta-regression analysis showed that both heart and pulse rates in the nebulizing furosemide group decreased by increasing the year of study and sample size (P <0.001). The heterogeneity among the studies was found to be 72.2%, which is classified as severe heterogeneity.

CONCLUSION

nebulizing furosemide can improve and normalize the vital signs and other respiratory variables in patients with COPD.

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.

Development and Characterization of Eudragit®-Based Electrospun Nanofibrous Mats and Their Formulation into Nanofiber Tablets for the Modified Release of Furosemide

Furosemide, a chloride channel blocker ordinarily used as a high-ceiling or loop diuretic, is practically insoluble in water and dilute acids. Due to its acidic nature, furosemide is mostly absorbed in the stomach and in the upper small intestine. Efforts have focused on the development of sustained release systems of furosemide in order to improve the effectiveness of the drug, which exhibits poor aqueous solubility and poor permeability. Recently, electrospun nanofibrous drug delivery systems have emerged as promising alternative solid-dosage forms due to their advantages of high porosity, high surface to volume ratio, and high drug-loading efficacy. Herein, a number of nanofibrous mats composed of different types of Eudragit® polymers in various concentrations and combinations loaded with furosemide were designed, successfully electrospun, and characterized using SEM, FTIR, DSC, and TGA analyses. The nanofibrous nonwovens were formulated in nanofiber tablets and the release profile of furosemide from them was evaluated at pH 1.2 and 6.8 and compared to that of physical mixture matrix tablets of analogous composition as well as to that of a commercial formulation. It was found that the release of furosemide was compatible with the gastroretentive and slower intestinal release requirements with a well-defined absorption window, while some nanofiber formulations could act as furosemide carriers in emergency situations where a relatively fast onset of its action is required, as in the case of critically ill post-traumatic patients.

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.

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

Background

Inhaled furosemide offers a potentially novel treatment for dyspnoea, which may reflect modulation of pulmonary stretch receptor feedback to the brain. Specificity of relief is unclear because different neural pathways may account for different components of clinical dyspnoea. Our objective was to evaluate if inhaled furosemide relieves the air hunger component (uncomfortable urge to breathe) but not the sense of breathing work/effort of dyspnoea.

Methods

A randomised, double blind, placebo-controlled crossover trial in 16 healthy volunteers studied in a university research laboratory. Each participant received 3 mist inhalations (either 40 mg furosemide or 4 ml saline) separated by 30–60 min on 2 test days. Each participant was randomised to mist order ‘furosemide-saline-furosemide’ (n- = 8) or ‘saline-furosemide-saline’ (n = 8) on both days. One day involved hypercapnic air hunger tests (mean ± SD PCO₂ = 50 ± 3.7 mmHg; constrained ventilation = 9 ± 1.5 L/min), the other involved work/effort tests with targeted ventilation (17 ± 3.1 L/min) and external resistive load (20cmH₂O/L/s). Primary outcome was ratings of air hunger or work/effort every 15 s on a visual analogue scale. During saline inhalations, 1.5 mg furosemide was infused intravenously to match the expected systemic absorption from the lungs when furosemide is inhaled. Corresponding infusions of saline during furosemide inhalations maintained procedural blinding. Average visual analogue scale ratings (%full scale) during the last minute of air hunger or work/effort stimuli were analysed using Linear Mixed Methods.

Results

Data from all 16 participants were analysed. Inhaled furosemide relative to inhaled saline significantly improved visual analogues scale ratings of air hunger (Least Squares Mean ± SE − 9.7 ± 2%; p = 0.0015) but not work/effort (+ 1.6 ± 2%; p = 0.903). There were no significant adverse events.

Conclusions

Inhaled furosemide was effective at relieving laboratory induced air hunger but not work/effort in healthy adults; this is consistent with the notion that modulation of pulmonary stretch receptor feedback by inhaled furosemide leads to dyspnoea relief that is specific to air hunger, the most unpleasant quality of dyspnoea.

Funding

Oxford Brookes University Central Research Fund.

Trial registration

ClinicalTrials.gov Identifier: NCT02881866. Retrospectively registered on 29th August 2018.

Effect of Inhaled Nebulized Furosemide (40 and 120 mg) on Breathlessness during Exercise in the Presence of External Thoracic Restriction in Healthy Men

Inhalation of nebulized furosemide has been shown to alleviate breathlessness provoked experimentally in health and disease; however, it remains unclear whether the efficacy of nebulized furosemide on breathlessness is dose-dependent. We tested the hypothesis that inhaled nebulized furosemide would be associated with a dose-dependent relief of breathlessness during exercise testing in the setting of abnormal restrictive constraints on tidal volume (V_T) expansion. In a randomized, double-blind, crossover study, 24 healthy men aged 25.3 ± 1.2 years (mean ± SE) completed a symptom-limited constant-load cycle endurance exercise test in the setting of external thoracic restriction via chest wall strapping to reduce vital capacity by ~20% following single-dose inhalation nebulized furosemide (40 and 120 mg) and 0.9% saline. Compared with 0.9% saline, neither 40 nor 120 mg of inhaled nebulized furosemide had an effect on ratings of perceived breathlessness during exercise or an effect on cardiometabolic, ventilatory, breathing pattern, or dynamic operating lung volume responses during exercise. Urine production rate, the percentage of participants reporting an "urge to urinate" and the intensity of perceived "urge to urinate" were all significantly greater after inhaling the 120 mg furosemide solution compared with both 0.9% saline and 40 mg furosemide solutions. We concluded that, under the experimental conditions of this study, inhalation of nebulized furosemide at doses of 40 and 120 mg did not alleviate breathlessness during exercise in healthy men.