Use Of Long-term Oxygen Therapy Research Articles

Validation of a novel device to objectively measure adherence to long-term oxygen therapy

We have developed a novel oxygen adherence monitor that objectively measures patient use of long-term oxygen therapy. The monitor attaches to the oxygen source and detects whether or not the patient is wearing the nasal cannula. The study's purpose was to validate the monitor's performance in patients with chronic obstructive pulmonary disease during wakefulness and sleep. Ten adult males with stable chronic obstructive pulmonary disease (mean +/- SD FEV1 37.7 +/- 14.9% of predicted) on long-term continuous oxygen therapy were tested in a sleep laboratory over a 12-13 hour period that included an overnight polysomnogram. The monitor's measurements were obtained at 4-minute intervals and compared to actual oxygen use determined by review of time-synchronized video recordings. The monitor made 1504/1888 (79.7%) correct detections (unprocessed data) across all participants: 957/1,118 (85.6%) correct detections during wakefulness and 546/770 (70.9%) during sleep. All errors were false negatives, ie, the monitor failed to detect that the participant was actually wearing the cannula. Application of a majority-vote filter to the raw data improved overall detection accuracy to 84.9%. The results demonstrate the monitor's ability to objectively measure whether or not men with chronic obstructive pulmonary disease are receiving their oxygen treatment. The ability to objectively measure oxygen delivery, rather than oxygen expended, may help improve the management of patients on long-term oxygen therapy.

Long-term oxygen therapy: are we prescribing appropriately?

Long-term oxygen therapy (LTOT) is the treatment proven to improve survival in chronic obstructive pulmonary disease (COPD) patients with chronic respiratory failure. It also appears to reduce the number of hospitalizations, increase effort capacity, and improve health-related quality of life. Standard LTOT criteria are related to COPD patients who have PaO2 < 60 mmHg, are in a clinical stable situation, and are receiving optimal pharmacological treatment. According to LTOT guidelines, oxygen should be prescribed for at least 18 hours per day although some authors consider 24 hours would be more beneficial. The benefits of LTOT depend on correction of hypoxemia. Arterial blood gases should be measured at rest. During exercise, an effort test should be done to assure adequate SaO2. During sleep, continuous monitoring of SaO2 and PaCO2 should be performed to confirm correction of SaO2 overnight. An arterial blood gas sample should be taken at awakening to assess PaCO, in order to prevent hypoventilation from the oxygen therapy. Several issues that need to be addressed are the use of LTOT in COPD patients with moderate hypoxemia, the efficacy of LTOT in patients who desaturate during exercise or during sleep, the optimal dosage of oxygen supplementation, LTOT compliance, and the LTOT prescription in diseases other than COPD.

Importance of Noninvasively Measured Respiratory Muscle Overload Among the Causes of Hospital Readmission of COPD Patients

To evaluate the influence of respiratory muscle overload and right cardiac overload among the possible risk factors of hospital readmission in a 1-year follow-up of a cohort of patients with moderate-to-severe COPD. A total of 112 COPD patients who were admitted consecutively to the hospital for acute exacerbation. At hospital discharge, we evaluated the conventional clinical and functional determinations in addition to the pressure-time index (PTI), which is obtained using the equation PTI = (Pawo/Pimax) x (Ti/Ttot) x 100, where Pawo represents the mean airway pressure measured at the mouth during spontaneous breathing, Pimax is the maximal inspiratory pressure, Ti is the inspiratory time, and Ttot is the total breathing cycle time. A cardiac echo-Doppler examination was carried out when patients were in stable condition and presented clinical signs of right cardiac overload prior to inclusion in the study. Multivariate analysis showed that the use of long-term oxygen therapy (LTOT) and high PTI (> 0.25) were independently related to the risk of hospital readmission. Patients receiving LTOT had higher Paco(2) (p < 0.05), FEV(1) percent predicted (p < 0.05), FVC percent predicted (p < 0.05), and Pao(2) (p < 0.05), and had higher Paco(2) (p < 0.05). An elevated systolic pulmonary arterial pressure (> 40 mm Hg) was also independently related, but only 28 patients had echo-Doppler data that could be used. At hospital discharge, noninvasively measured respiratory muscle overload as well as the use of LTOT were associated with an increased risk of hospital readmission for exacerbation in patients with moderate-to-severe COPD.

Drugs (including oxygen) in severe COPD

Access to comprehensive guidelines on the management of chronic obstructive pulmonary disease (COPD) is now available, and several treatment goals of therapy have been identified from these guidelines, which have since been studied in clinical trials. Drug therapy is a key component of an individual patient's management plan, particularly in more severe disease. During the past few years, a number of new drug treatments have become available, although these are not always appropriately prescribed; this is particularly the case for oxygen. For patients with a history of exacerbations, there is good evidence for the use of inhaled long-acting anticholinergic agents or combined inhaled steroids and long-acting beta-agonists. Evidence for prophylactic antibiotics and antioxidant agents is lacking. Nutritional and calorie supplementation have not been shown to improve exercise capacity. Statins may improve outcomes in COPD, but prospective trials are needed to confirm this. The evidence for the use of long-term oxygen therapy in hypoxaemic patients is robust. Ambulatory oxygen improves exercise capacity, but whether it is used appropriately is in doubt. Overall, short burst oxygen therapy does not offer a benefit and therefore cannot be recommended.

Influência do sistema de fornecimento de oxigênio na qualidade de vida de pacientes com hipoxemia crônica

To evaluate the health-related quality of life of patients with chronic obstructive pulmonary disease receiving long-term oxygen therapy (LTOT) at home through oxygen cylinders and compare these results with those obtained six months after the transition from oxygen cylinders to oxygen concentrators. A total of 45 patients were evaluated. Of those, 24 had chronic hypoxemia and 21 presented no evidence of hypoxemia. The patients with chronic hypoxemia had been regularly receiving LTOT for at least the last six months and were evaluated at baseline, while using cylinders, and six months after the transition from cylinders to concentrators. The non-hypoxemic patients were evaluated at the same time points as were the hypoxemic patients. In order to evaluate quality of life, a version of the Saint George's Respiratory Questionnaire (SGRQ), translated and validated for use in Brazil, was administered. At baseline, quality of life, as evaluated using the total score and the symptom and impact domain scores of the SGRQ, was more impaired in the hypoxemic patients than in the non-hypoxemic patients. After six months of using the concentrators, the hypoxemic patients presented a significant improvement in the quality of life, and, at that time, no difference was found between the patients with and without hypoxemia. Our findings show that quality of life is impaired in patients with chronic obstructive pulmonary disease and chronic hypoxemia, that their quality of life can be improved through regular use of LTOT, and that the oxygen delivery system has an influence on this improvement.

Exacerbations, Hospital Admissions and Impaired Health Status in Chronic Obstructive Pulmonary Disease

Impaired health status may be a risk factor for frequent exacerbations and hospital admission and, in turn, exacerbations and admissions may further impair the health status of patients with COPD. We have investigated the variables associated with frequent exacerbations (3 or more per year) and admission, with particular interest in health status, in a cohort of ambulatory patients with moderate to severe COPD attended by chest physicians in Spain. A total of 227 investigators included 1057 patients with a mean predicted FEV1 of 41.8%. The mean total score on the St. George's Respiratory Questionnaire (SGRQ) was 47.9 units, and 300 patients (28.4%) had 3 or more exacerbations the previous year and 344 (32.6%) were admitted at least once during the same period. In multivariate analysis only the SGRQ total score was significantly associated with both frequent exacerbations (OR = 1.04; 95% CI = 1.01-2.12; p<0.0001) and admission (OR = 1.01; 95% CI = 1.00-1.02; p = 0.0008). Other variables significantly associated with frequent exacerbations were chronic mucus hypersecretion, increased baseline dyspnea, comorbidity, GOLD stage IV and treatment with inhaled corticosteroids. Variables associated with admission were lower educational level, increased number of exacerbations, use of long-term oxygen therapy and use of short acting beta-2 agonists. An impaired health status is associated with an increased number of exacerbations and with admission to hospital in the previous year. These results, together with previous studies, confirm that impairment in health status in COPD is both a marker of risk for, and a consequence of, frequent exacerbations and admissions.

Predictors of 1-year mortality in patients discharged from hospital following acute exacerbation of chronic obstructive pulmonary disease

acute exacerbation of COPD (AECOPD) is a major cause of hospital admission, and predicts subsequent medium-term mortality. We aimed to examine mortality predictors in patients discharged from hospital after AECOPD. we obtained baseline demographic and clinical data from 100 patients (mean age (range)=73 (60-98) years; 48 males) admitted with AECOPD. All completed the following validated questionnaires: a quality of life questionnaire (Breathing Problems Questionnaire; BPQ); a screening questionnaire for depression (Brief Assessment Schedule Depression Cards; BASDEC); a disability questionnaire (Manchester Respiratory Activities of Daily Living questionnaire; MRADL). Following discharge all were prospectively followed and survival/mortality at 12 months confirmed from hospital notes and by contacting general practitioners. the prevalence of depression at recruitment was 56%. One-year mortality in the whole group was 36%. Odds ratios (95% confidence intervals) for mortality predictors (univariate logistic regression analysis) were: use of long-term oxygen therapy=2.72 (1.06-6.97); subsequent readmission=2.57 (1.08-6.12); MRADL score=0.87 (0.80-0.94) (disability predicting death); BASDEC score=1.13 (1.02-1.26) (depression predicting death); BPQ score=1.08 (1.04-1.12) (low quality of life predicting death); length of original hospital stay=1.03 (1.00-1.07). On multivariate logistic regression analysis the only mortality predictor was BPQ with an odds ratio (95% confidence limits) of 1.13 (1.04-1.22). In terms of mortality prediction for individuals, a threshold MRADL score of <12 gave a sensitivity of 86%, specificity of 55%, positive predictive value of 88% and negative predictive value of 52%, with similar predictive values using BPQ as an independent variable. 1-year mortality after AECOPD admission is high. The presence of depressive illness (which is extremely common), and levels of both disability and impairment of quality of life are univariate predictors of 1-year mortality in this patient group. This model may be useful in predicting prognosis for individuals and thus in guiding treatment decisions.

Survival of Patients With Bronchiectasis After the First ICU Stay for Respiratory Failure

Respiratory failure (RF) is a frequent cause of death among patients with bilateral bronchiectasis. An ICU admission is commonly required, and neither short-term or long-term outcomes have been studied. We performed a retrospective study over a 10-year period (January 1990 to March 2000). All patients with bilateral bronchiectasis admitted for the first time in the medical ICU for RF were reviewed. Patients with cystic fibrosis were excluded. Forty-eight patients (mean age +/- SD, 63 +/- 11 years; mean simplified acute physiology score [SAPS] II, 32 +/- 12) of whom 25% received long-term oxygen therapy (LTOT) were identified. All the patients were treated with intensive medical care, associated with noninvasive ventilation in 13 patients (27%), and 26 patients (54%) required intubation. Nine patients (19%) died in the ICU. The 1-year mortality rate was 40%. Among the variables recorded at ICU admission, age > 65 years (p = 0.002), SAPS II score > 32 (p = 0.012), use of LTOT (p = 0.047), and intubation (p = 0.027) were associated with reduced survival in univariate analysis by Cox regression. Multivariate analysis by Cox proportional hazard model showed that age > 65 years (relative risk [RR], 2.70; 95% confidence interval [CI], 1.15 to 6.29) and use of LTOT (RR, 2.52; 95% CI, 1.15 to 5.54) were independently associated with reduced survival. We performed the first study providing information related to the impact of the first ICU stay for RF on long-term outcomes for patients with bilateral bronchiectasis. Age > 65 years and prior use of LTOT were associated with reduced survival.

Paradoxical results in the study of risk factors of chronic obstructive pulmonary disease (COPD) re-admission

We have previously reported an apparently paradoxical association between medical care related factors and an increased risk of chronic obstructive pulmonary disease (COPD) re-hospitalisation, in a cohort of 346 COPD subjects from Barcelona, Spain. Confounding by severity or by indication is a plausible explanation. We tested the confounding effect of severity-related variables on these paradoxical associations. Forced expiratory volume in one second (FEV 1), arterial oxygen pressure ( PO 2) and previous COPD admissions were associated with: (1) the presence of medical care related factors, and (2) re-admission during follow-up. Risks of re-admission associated with most of the medical care related factors were reduced after adjustment for the severity variables. The risk associated with long-term oxygen therapy use changed from a crude OR of 2.36 (95% CI: 1.79–3.11) to an adjusted OR of 1.38 (0.95–2.00), while that associated with anticholinergics use varied from 3.52 (2.37–5.21) to 2.10 (1.32–3.36)). We concluded that the excess risk of COPD re-admission associated with medical care related factors might be partially due to confounding by indication. Residual confounding may still account for part of the remaining excess risk. True adverse effects of some pharmacological treatments cannot be excluded.

Mortality predictors in disabling chronic obstructive pulmonary disease in old age.

prospectively to evaluate predictors of mortality in elderly patients with disabling chronic obstructive pulmonary disease. 137 (69 men) outpatients, aged 60-89 (mean 73) years with symptomatic disabling chronic obstructive pulmonary disease. We collected baseline demographic and physiological data. Subjects completed the Manchester Respiratory Activities of Daily Living Questionnaire, the Brief Assessment Schedule Depression Cards a screening questionnaire for depression, the Breathing Problems Questionnaire measuring quality of life, and the Montgomery Asberg Depression Rating Scale measuring severity of depression. All subjects were followed prospectively and survival and mortality data were confirmed by contacting general practitioners and scrutinising hospital notes at 30 months. the mean (standard deviation) of one second forced expiratory volume was 0.89 (0.3) litres. At 30 months, 44 patients (21 men, aged 61-89 [mean 75] years: 32% of the total) had died. Mean (standard deviation) baseline one second forced expiratory volume of those dying was 0.71 (0.2) litres. On logistic regression analysis, predictors of mortality were: Manchester Respiratory Activities Of Daily Living Questionnaire score (odds ratio=0.88, 95% confidence interval=0.80-0.97); pre-bronchodilator one second forced expiratory volume (odds ratio=0.04, confidence interval=0.005-0.32); body mass index (odds ratio=0.87, confidence interval=0.79-0.97); and long term oxygen therapy (odds ratio=3.17, confidence interval=1.04-8.36). Current smoking status, pack-years smoked, depression scores, quality of life scores, co-morbid diseases and social class did not predict mortality. disability, use of long-term oxygen therapy, pre-bronchodilator lung function and body-mass index were independent predictors of mortality in elderly patients with severe chronic obstructive pulmonary disease.

Corticosteroids and obstructive lung disease

In the first of two articles, Anne Baird examines the issues surrounding the use of inhaled therapy for COPD and considers the experience of Mrs White.The use of long-term oxygen therapy will be discussed in the forthcoming article.

A review of long-term oxygen therapy for chronic obstructive pulmonary disease

This study aimed to review the evidence for the use of long-term oxygen therapy for patients with chronic obstructive pulmonary disease (COPD).The design was a systematic Cochrane review of randomized controlled trials (RCTs) of long-term oxygen therapy for COPD and main outcome measure was survival on home oxygen therapy.Five RCTs were identified. Data from two trials of nocturnal oxygen therapy in mild to moderate hypoxaemia were aggregated. Data from the other three trials could not be aggregated because of differences in trial design and patient selection. Treatment with continuous versus nocturnal oxygen therapy produced a significant improvement in mortality after 24 months [Peto odds ratio 0·45, 95% confidence interval (95% CI) 0·25–0·81] for the continuous therapy group. Treatment with oxygen therapy versus no oxygen therapy showed a significant improvement in mortality after five years in the group receiving oxygen therapy (Peto odds ratio 0·42, 95% CI 0·18–0·98). There was no difference in mortality for patients with COPD and mild to moderate daytime hypoxaemia and nocturnal desaturation receiving nocturnal oxygen therapy versus no oxygen therapy or sham treatment. Long-term oxygen therapy versus no oxygen therapy in patients with COPD and moderate hypoxaemia had no effect on survival.In conclusion, long-term oxygen therapy improved survival in a selected group of COPD patients with severe hypoxaemia but few co-morbidities. Long-term oxygen therapy did not improve survival in patients with moderate hypoxaemia or in those with mild to moderate hypoxaemia and arterial desaturation at night.

Long-term oxygen therapy.

The role of long-term oxygen therapy in the management of patients with hypoxemia is discussed. A brief history of the use of long-term oxygen therapy and its benefits is provided. The actual prescription of long-term oxygen therapy and reimbursement issues are reviewed. The use of long-term oxygen therapy, particularly in the home and for travel is addressed. In recent times, the focus of oxygen therapy delivery has shifted to allow patients receiving repeated oxygen therapy to have increased mobility. Lighter and more portable equipment is now used, and oxygen-conserving devices have been developed that allow the patient's oxygen supply to last longer. An update on this equipment and these devices is provided.

Long-term Oxygen Therapy at Home: Compliance With Medical Prescription and Effective Use of Therapy

Daily duration of oxygen administration is an important factor in the effectiveness of long-term oxygen therapy (LTOT) for hypoxic chronic pulmonary disease. We have assessed the daily use of oxygen therapy in 930 patients with COPD and examined factors associated with the effective use of this treatment. Objective daily duration of oxygen use over a 3-month period was prospectively measured using the counter clock of the oxygen concentrators or by weighing the liquid oxygen container at each delivery. A questionnaire was filled in by an independent investigator asking about home situation, lifestyle, and whether oxygen therapy was used during all domestic and outside activities. In addition, prescribing physicians were asked about the duration and modalities of oxygen prescribed in each case. The patients had been receiving LTOT for 36 +/- 24 months and had hypoxemia (PaO2 = 56 +/- 9 mm Hg), hypercapnia (PaCO2 = 47 +/- 8 mm Hg), and severe airflow obstruction (FEV1/VC = 42 +/- 14%). The mean duration of oxygen treatment prescribed was 16 +/- 3 h/d. The mean duration of oxygen therapy achieved was 14.5 +/- 5 h, but only 45% of the patients achieved oxygen therapy for 15 h or more per day. Patients with effective use of LTOT, ie receiving oxygen therapy for at least 15 h/d, were significantly more hypoxic (PaO2 = 54 +/- 9 vs 57 +/- 9 mm Hg; p < 0.001), more hypercapnic (PaCO2 = 48 +/- 8 vs 46 +/- 7 mm Hg; p < 0.005), and also more obstructed (FEV1/VC = 39.5 +/- 13 vs 45 +/- 14%; p < 0.001) than the rest of the patients under treatment. Other factors associated with effective use of oxygen were (1) initial prescription for 15 h or more per day, (2) supplementary education on oxygen therapy by a nurse or physiotherapist, (3) cessation of smoking, (4) use of oxygen in all domestic situations (toilet, meals, leisure, etc.), and (5) absence of side effects from oxygen treatment. Attention by the prescribing physicians to such factors could optimize oxygen prescription and constitute goals for education of patients.

Domiciliary oxygen--by liquid or concentrator? Working Group on Oxygen Therapy of IUATLD

A few hypoxaemic and even less non-hypoxaemic patients with chronic obstructive pulmonary disease (COPD) benefit from portable oxygen. For these few, selected by double-blind tests against compressed air, liquid oxygen would seem more convenient and efficient. The extra cost of treating all hypoxaemic COPD patients with liquid oxygen by displacing the oxygen concentrator is not justified on the basis of current knowledge. The application of differing oxygen delivery systems to COPD patients requires more evaluation. The selection of patients for long-term oxygen therapy (LTOT) still presents major difficulties, which reflects on the numbers of patients likely to benefit from portable oxygen. No studies have yet shown the benefit of LTOT to chronic respiratory failure in other disorders such as lung fibrosis. As the pathophysiology is quite different, extension of the use of LTOT and portable oxygen to non-COPD patients must be treated with great caution.

Long-Term Oxygen Therapy in COPD

Over the last decade, there has been substantial expansion in the use of chronically-administered oxygen among patients with chronic obstructive pulmonary disease (COPD). Such expansion reflects the following two facts: (1) the major mortality and disability impact of COPD; and (2) the frequency of demonstrable hypoxemia among such patients. Ranking as the sixth cause of death in the United States, COPD is also second only to coronary artery disease as a cause of permanent disability among American adults. 1 Lertzman MM Cherniack RM Rehabilitation of patients with chronic obstructive pulmonary disease. Am Rev Respir Dis. 1976; 114: 1145-1165 PubMed Google Scholar The frequency of arterial hypoxemia among COPD patients is widely-appreciated and well-documented. 2 Block AJ Burrows B Kanner RF Lilker E Mithoefer C Petty T Oxygen administration in the home. Am Rev Respir Dis. 1977; 115: 897-899 PubMed Google Scholar , 3 Flick MR Block AJ Chronic oxygen therapy. Med Clin N Am. 1977; 61: 1397-1408 Crossref Scopus (4) Google Scholar , 4 Block AJ Low flow oxygen therapy: treatment of the ambulant patient. Am Rev Respir Dis. 1974; 110: 71-84 Google Scholar However, the use of long-term oxygen therapy implies a linkage between these two facts, one that has been difficult to establish. Put simply, that linkage requires a positive answer to the following question: Does relief of arterial hypoxemia alter either the mortality or the extent of disability among COPD patients?