Oxygen use--patients define symptomatic benefit discerningly

Does home oxygen therapy (HOT) in addition to standard care reduce disease severity and improve symptoms in people with chronic heart failure? A randomised trial of home oxygen therapy for patients with chronic heart failure

BACKGROUND

Home oxygen therapy (HOT) is commonly used for patients with severe chronic heart failure (CHF) who have intractable breathlessness. There is no trial evidence to support its use.

OBJECTIVES

To detect whether or not there was a quality-of-life benefit from HOT given as long-term oxygen therapy (LTOT) for at least 15 hours per day in the home, including overnight hours, compared with best medical therapy (BMT) in patients with severely symptomatic CHF.

DESIGN

A pragmatic, two-arm, randomised controlled trial recruiting patients with severe CHF. It included a linked qualitative substudy to assess the views of patients using home oxygen, and a free-standing substudy to assess the haemodynamic effects of acute oxygen administration.

SETTING

Heart failure outpatient clinics in hospital or the community, in a range of urban and rural settings.

PARTICIPANTS

Patients had to have heart failure from any aetiology, New York Heart Association (NYHA) class III/IV symptoms, at least moderate left ventricular systolic dysfunction, and be receiving maximally tolerated medical management. Patients were excluded if they had had a cardiac resynchronisation therapy device implanted within the past 3 months, chronic obstructive pulmonary disease fulfilling the criteria for LTOT or malignant disease that would impair survival or were using a device or medication that would impede their ability to use LTOT.

INTERVENTIONS

Patients received BMT and were randomised (unblinded) to open-label LTOT, prescribed for 15 hours per day including overnight hours, or no oxygen therapy.

MAIN OUTCOME MEASURES

The primary end point was quality of life as measured by the Minnesota Living with Heart Failure (MLwHF) questionnaire score at 6 months. Secondary outcomes included assessing the effect of LTOT on patient symptoms and disease severity, and assessing its acceptability to patients and carers.

RESULTS

Between April 2012 and February 2014, 114 patients were randomised to receive either LTOT or BMT. The mean age was 72.3 years [standard deviation (SD) 11.3 years] and 70% were male. Ischaemic heart disease was the cause of heart failure in 84%; 95% were in NYHA class III; the mean left ventricular ejection fraction was 27.8%; and the median N-terminal pro-B-type natriuretic hormone was 2203 ng/l. The primary analysis used a covariance pattern mixed model which included patients only if they provided data for all baseline covariates adjusted for in the model and outcome data for at least one post-randomisation time point (n = 102: intervention, n = 51; control, n = 51). There was no difference in the MLwHF questionnaire score at 6 months between the two arms [at baseline the mean score was 54.0 (SD 18.4) for LTOT and 54.0 (SD 17.9) for BMT; at 6 months the mean score was 48.1 (SD 18.5) for LTOT and 49.0 (SD 20.2) for BMT; adjusted mean difference -0.10, 95% confidence interval (CI) -6.88 to 6.69; p = 0.98]. At 3 months, the adjusted mean MLwHF questionnaire score was lower in the LTOT group (-5.47, 95% CI -10.54 to -0.41; p = 0.03) and breathlessness scores improved, although the effect did not persist to 6 months. There was no effect of LTOT on any secondary measure. There was a greater number of deaths in the BMT arm (n = 12 vs. n = 6). Adherence was poor, with only 11% of patients reporting using the oxygen as prescribed.

CONCLUSIONS

Although the study was significantly underpowered, HOT prescribed for 15 hours per day and subsequently used for a mean of 5.4 hours per day has no impact on quality of life as measured by the MLwHF questionnaire score at 6 months. Suggestions for future research include (1) a trial of patients with severe heart failure randomised to have emergency oxygen supply in the house, supplied by cylinders rather than an oxygen concentrator, powered to detect a reduction in admissions to hospital, and (2) a study of bed-bound patients with heart failure who are in the last few weeks of life, powered to detect changes in symptom severity.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN60260702.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 75. See the NIHR Journals Library website for further project information.

The evidence base for oxygen for chronic refractory breathlessness: issues, gaps, and a future work plan

Breathlessness or "shortness of breath," medically termed dyspnea, is a common and distressing symptom featuring strongly in advanced lung, cardiac, and neuromuscular diseases; its prevalence and intensity increase as death approaches. However, despite the increasing understanding in the genesis of breathlessness, as well as an increasing portfolio of treatment options, breathlessness is still difficult to manage and engenders helplessness in caregivers and health care professionals and fear for patients. Although hypoxemia does not appear to be the dominant driver for breathlessness in advanced disease, the belief that oxygen is important for the relief of acute, chronic, and acute-on-chronic shortness of breath is firmly embedded in the minds of patients, caregivers, and health care professionals. This article presents current understanding of the use of oxygen for treating refractory breathlessness in advanced disease. The objective is to highlight what is still unknown, set a research agenda to resolve these questions, and highlight methodological issues for consideration in planned studies.

The clinical and social dimensions of prescribing palliative home oxygen for refractory dyspnea

BACKGROUND

Chronic breathlessness is a significant problem in palliative care and oxygen is often prescribed in an attempt to ameliorate it. Often, this prescription falls outside the current funding guidelines for long-term home oxygen use. The aim of this qualitative study was to understand the factors that most influence Australian specialist palliative care nurses' initiation of home oxygen for their patients.

METHODS

A series of focus groups were held across three states in Australia in 2011 involving specialist palliative care nurses. The invitation to the nurses was sent by e-mail through their national association. Recorded and transcribed data were coded for themes and subthemes. A summary, which included quotes, was provided to participants to confirm.

RESULTS

Fifty-one experienced palliative care nurses participated in seven focus groups held in three capital cities. Two major themes were identified: 1) logistic/health service issues (not reported in this paper as specific to the Australian context) involving the local context of prescribing and, 2) clinical care issues that involved assessing the patient's need for home oxygen and ongoing monitoring concerns. Palliative care nurses involved in initiating or prescribing oxygen often reported using oxygen as a second-line treatment after other interventions had been trialed and these had not provided sufficient symptomatic benefit. Safety issues were a universal concern and a person living alone did not emerge as a specific issue among the nurses interviewed.

CONCLUSION

The role of oxygen is currently seen as a second-line therapy in refractory dyspnea by specialist palliative care nurses.

Improving the management of dyspnea in the community using rapid learning approaches

Patients with chronic pulmonary disease often suffer from breathlessness or dyspnea. Traditional evidence generation techniques to expand upon current treatment paradigms are limited by the significant delay between study initiation and clinical implementation of findings. Rapid learning health care is a novel approach to health care delivery that relies on intelligent and continuous integration of clinical and research data sets to deliver personalized medicine using the most current evidence available. Results of important studies in the management of chronic respiratory disease are presented in brief; however, the focus of this review is on evidence supporting the implementation of a rapid learning model for symptom management. Recent findings suggest that a rapid learning system is feasible and acceptable to patients with advanced illness, helps monitor symptoms overtime, facilitates study of the impact of novel interventions, and can identify unrecognized needs and concerns. A rapid learning model improves comprehensive assessment, timeliness of intervention, and accrual of contemporaneous data to support best practice that tailors care specific to the needs of patients as their disease and lifestyle change overtime. Using the rapid learning health care model, data collected in the process of routine care can simultaneously function both as clinical information and as a resource for research on patient-centered experiences and outcomes.

Dyspnea review for the palliative care professional: treatment goals and therapeutic options

Although dyspnea is frequently encountered in the palliative care setting, its optimal management remains uncertain. Clinical approaches begin with accurate assessment, as delineated in part one of this two-part series. Comprehensive dyspnea assessment, which encompasses the physical, emotional, social, and spiritual aspects of this complex symptom, guide the clinician in choosing therapeutic approaches herein presented as part two. Global management of dyspnea is appropriate both as complementary to disease-targeted treatments that target the underlying etiology, and as the sole focus when the symptom has become intractable, disease is maximally treated, and goals of care shift to comfort and quality of life. In this setting, current evidence supports the use of oral or parenteral opioids as the mainstay of dyspnea management, and of inhaled furosemide and anxiolytics as adjuncts. Nonpharmacologic interventions such as acupuncture and pulmonary rehabilitation have potential effectiveness, although further research is needed, and use of a simple fan warrants consideration given its potential benefit and minimal burden and cost.

Symptomatic oxygen for non-hypoxaemic chronic obstructive pulmonary disease

BACKGROUND

Dyspnoea is a common symptom in chronic obstructive pulmonary disease (COPD). People who are hypoxaemic may be given long-term oxygen relief therapy (LTOT) to improve their life expectancy and quality of life. However, the symptomatic benefit of home oxygen therapy in mildly or non-hypoxaemic people with COPD with dyspnoea who do not meet international funding criteria for LTOT (PaO(2)< 55 mmHg or other special cases) is unknown.

OBJECTIVES

To determine the efficacy of oxygen versus medical air for relief of subjective dyspnoea in mildly or non-hypoxaemic people with COPD who would not otherwise qualify for home oxygen therapy. The main outcome was patient-reported dyspnoea and secondary outcome was exercise tolerance.

SEARCH STRATEGY

We searched the Cochrane Airways Group Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE, to November 2009, to identify randomised controlled trials. We handsearched reference lists of included articles.

SELECTION CRITERIA

We only included randomised controlled trials of oxygen versus medical air in mildly or non-hypoxaemic people with COPD. Two review authors independently assessed articles for inclusion.

DATA COLLECTION AND ANALYSIS

One review author completed data extraction and methodological quality assessment. A second review author then over-read evidence tables to assess for accuracy.

MAIN RESULTS

Twenty-eight trials on 702 patients met the criteria for inclusion; 18 trials (431 participants) were included in the meta-analysis. Oxygen reduced dyspnoea with a standardised mean difference (SMD) of -0.37 (95% confidence interval (CI) -0.50 to -0.24, P < 0.00001). We observed significant heterogeneity.

AUTHORS' CONCLUSIONS

Oxygen can relieve dyspnoea in mildly and non-hypoxaemic people with COPD who would not otherwise qualify for home oxygen therapy. Given the significant heterogeneity among the included studies, clinicians should continue to evaluate patients on an individual basis until supporting data from ongoing, large randomised controlled trials are available.

Effect of palliative oxygen versus room air in relief of breathlessness in patients with refractory dyspnoea: a double-blind, randomised controlled trial

BACKGROUND

Palliative oxygen therapy is widely used for treatment of dyspnoea in individuals with life-limiting illness who are ineligible for long-term oxygen therapy. We assessed the effectiveness of oxygen compared with room air delivered by nasal cannula for relief of breathlessness in this population of patients.

METHODS

Adults from outpatient clinics at nine sites in Australia, the USA, and the UK were eligible for enrolment in this double-blind, randomised controlled trial if they had life-limiting illness, refractory dyspnoea, and partial pressure of oxygen in arterial blood (PaO(2)) more than 7.3 kPa. Participants were randomly assigned in a 1:1 ratio by a central computer-generated system to receive oxygen or room air via a concentrator through a nasal cannula at 2 L per min for 7 days. Participants were instructed to use the concentrator for at least 15 h per day. The randomisation sequence was stratified by baseline PaO(2) with balanced blocks of four patients. The primary outcome measure was breathlessness (0-10 numerical rating scale [NRS]), measured twice a day (morning and evening). All randomised patients who completed an assessment were included in the primary analysis for that data point (no data were imputed). This study is registered, numbers NCT00327873 and ISRCTN67448752.

FINDINGS

239 participants were randomly assigned to treatment (oxygen, n=120; room air, n=119). 112 (93%) patients assigned to receive oxygen and 99 (83%) assigned to receive room air completed all 7 days of assessments. From baseline to day 6, mean morning breathlessness changed by -0.9 points (95% CI -1.3 to -0.5) in patients assigned to receive oxygen and by -0.7 points (-1.2 to -0.2) in patients assigned to receive room air (p=0.504). Mean evening breathlessness changed by -0.3 points (-0.7 to 0.1) in the oxygen group and by -0.5 (-0.9 to -0.1) in the room air group (p=0.554). The frequency of side-effects did not differ between groups. Extreme drowsiness was reported by 12 (10%) of 116 patients assigned to receive oxygen compared with 14 (13%) of 108 patients assigned to receive room air. Two (2%) patients in the oxygen group reported extreme symptoms of nasal irritation compared with seven (6%) in the room air group. One patient reported an extremely troublesome nose bleed (oxygen group).

INTERPRETATION

Since oxygen delivered by a nasal cannula provides no additional symptomatic benefit for relief of refractory dyspnoea in patients with life-limiting illness compared with room air, less burdensome strategies should be considered after brief assessment of the effect of oxygen therapy on the individual patient.

FUNDING

US National Institutes of Health, Australian National Health and Medical Research Council, Duke Institute for Care at the End of Life, and Doris Duke Charitable Foundation.

Patients' experience of oxygen therapy and dyspnea: a qualitative study in home palliative care

BACKGROUND

Dyspnea is a common and distressing symptom in advanced cancer patients. Our preliminary work shows that in the home palliative care population sampled for this study, the prevalence of dyspnea is 29.5% and of those, 26.2% used oxygen therapy. Previous studies suggested that oxygen therapy can be a burden to patients.

PURPOSE

This study seeks to report the prevalence and describe the experience of dyspnea, pattern of oxygen use, and patients' perceived benefits and/or burdens of oxygen therapy in home palliative care patients receiving oxygen therapy.

METHODS

Qualitative in-depth interviews, using an interview guide, were conducted with eight participants in their homes. Thematic analysis was performed using a framework approach.

RESULTS

All patients in this project used oxygen most of the time. The descriptions of shortness of breath varied and were nonspecific. The patients identified more advantages than disadvantages. The advantages of oxygen use included increased functional capacity, patients' perceiving oxygen as a life-saving intervention, as well as a symptom-management tool. The identified disadvantages were decreased mobility, discomfort related to the nasal prongs, barriers to accessing oxygen therapy and noise related to the equipment.

CONCLUSION

The advantages of oxygen usage outweighed the disadvantages for this sample of patients in the home palliative setting.

Does palliative home oxygen improve dyspnoea? A consecutive cohort study

Palliative oxygen for refractory dyspnoea is frequently prescribed, even when the criteria for long-term home oxygen (based on survival, rather than the symptomatic relief of breathlessness) are not met. Little is known about how palliative home oxygen affects symptomatic breathlessness. A 4-year consecutive cohort from a regional community palliative care service in Western Australia was used to compare baseline breathlessness before oxygen therapy with dyspnoea sub-scales on the symptom assessment scores (SAS; 0-10) 1 and 2 weeks after the introduction of oxygen. Demographic and clinical characteristics of people who responded were included in a multi-variable logistic regression model. Of the study population (n = 5862), 21.1% (n = 1239) were prescribed oxygen of whom 413 had before and after data that could be included in this analysis. The mean breathlessness before home oxygen was 5.3 (SD 2.5; median 5; range 0-10). There were no significant differences overall at 1 or 2 weeks (P = 0.28) nor for any diagnostic sub-groups. One hundred and fifty people (of 413) had more than a 20% improvement in mean dyspnoea scores. In multi-factor analysis, neither the underlying diagnosis causing breathlessness nor the demographic factors predicted responders at 1 week. Oxygen prescribed on the basis of breathlessness alone across a large population predominantly with cancer does not improve breathlessness for the majority of people. Prospective randomised trials in people with cancer and non-cancer are needed to determine whether oxygen can reduce the progression of breathlessness compared to a control arm.

Symptom control and palliative care: management of breathlessness

Breathlessness remains a common and significant problem in palliative care. This article reviews the most commonly used interventions and discusses strategies to improve this symptom.

Oxygen for relief of dyspnea: what is the evidence?

PURPOSE OF REVIEW

Refractory dyspnea is a common and distressing symptom complicating respiratory illness, including chronic obstructive pulmonary disease, and life-limiting illnesses in general, including cancer. Oxygen is often prescribed for relief of dyspnea and several consensus guidelines support this practice. The goal of this review is to outline the evidence for the use of oxygen for relief of dyspnea, with specific attention to situations in which oxygen is not already funded through long-term oxygen treatment guidelines (i.e., when PaO2 is >/=55 mmHg; also known as palliative oxygen).

RECENT FINDINGS

Several recent systematic reviews, two focusing on people with chronic obstructive pulmonary disease and the other focusing on people with cancer, strengthen the evidence base behind the use of palliative oxygen for relief of refractory dyspnea, and support the observation that there are subgroups of people who benefit from oxygen, such as individuals with chronic obstructive pulmonary disease.

SUMMARY

The data highlighted in this review support the belief that certain individuals benefit from the use of palliative oxygen but continue to suggest that definitive randomized trials are required to fully establish the benefit of palliative oxygen and to delineate characteristics predictive of benefit.

Oxygen for relief of dyspnoea in mildly- or non-hypoxaemic patients with cancer: a systematic review and meta-analysis

The aim of this study was to determine the efficacy of palliative oxygen for relief of dyspnoea in cancer patients. MEDLINE and EMBASE were searched for randomised controlled trials, comparing oxygen and medical air in cancer patients not qualifying for home oxygen therapy. Abstracts were reviewed and studies were selected using Cochrane methodology. The included studies provided oxygen at rest or during a 6-min walk. The primary outcome was dyspnoea. Standardised mean differences (SMDs) were used to combine scores. Five studies were identified; one was excluded from meta-analysis due to data presentation. Individual patient data were obtained from the authors of the three of the four remaining studies (one each from England, Australia, and the United States). A total of 134 patients were included in the meta-analysis. Oxygen failed to improve dyspnoea in mildly- or non-hypoxaemic cancer patients (SMD=-0.09, 95% confidence interval -0.22 to 0.04; P=0.16). Results were stable to a sensitivity analysis, excluding studies requiring the use of imputed quantities. In this small meta-analysis, oxygen did not provide symptomatic benefit for cancer patients with refractory dyspnoea, who would not normally qualify for home oxygen therapy. Further study of the use of oxygen in this population is warranted given its widespread use.