Hyperbaric oxygen therapy and mortality from carbon monoxide poisoning: A nationwide observational study

BackgroundThe effects of hyperbaric oxygen therapy (HBOT) on mortality or morbidity in patients with carbon monoxide (CO) poisoning remain unknown. We examined the effects of HBOT on CO poisoning and further strived to delineate its inherent effects on specific subgroups of patients using a nationwide inpatient database.MethodsWe identified adult patients with CO poisoning who were registered in the Japanese Diagnosis Procedure Combination inpatient database from 2010 to 2016. Propensity score-matching was performed to compare patients who received HBOT within 1 day of admission (HBOT group) with those who did not receive HBOT (control group). The primary outcome was in-hospital mortality. The secondary outcomes were a depressed mental status and reduced activities of daily living (ADL) at discharge. We also performed subgroup analyses divided according to severity of CO poisoning.ResultsEligible patients were categorized into the HBOT group (n = 2034) or the control group (n = 4701). One-to-one propensity score-matching created 2034 pairs. In-hospital mortality was not significantly different between the HBOT and control groups (0.8% vs. 1.2%, risk difference: −0.4%, 95% confidence interval: −1.0 to 0.2). Patients in the HBOT group had significantly lower proportions of a depressed mental status and reduced ADL at discharge than did those in the control group. Similar associations were shown in the non-severe poisoning subgroup.ConclusionsAlthough HBOT was not significantly associated with reduced mortality, it was significantly associated with a favorable consciousness level and ADL in patients with CO poisoning. HBOT may be beneficial even for patients with non-severe CO poisoning.     

Technological dependency--the experience of using home ventilators and long-term oxygen therapy: patients' and families' perspective

Technological dependency is defined as a short or long‐term reliance on machines and techniques to evaluate, satisfy or resolve health problems. In nursing technological dependency has been explored in the context of caring. Hitherto it has been maintained that technology and caring are contradictory, but a more prominent view is that technology and caring can and must be reconciled to provide high‐quality care. This study describes patients’ and families’ experience of long‐term home treatment with noninvasive ventilation during sleep with or without additional oxygen therapy. Considering the potential burden of undergoing this treatment the research question is: What is patients’ and families’ experience of being dependent on technical breathing assistance during sleep? The methodological approach draws from interpretive phenomenology and narrative analysis. Participants were six patients aged 45–70, five spouses and one daughter. Data, generated through two 1‐hour semi‐structured interviews with each pair of participants, were analysed into themes. Results are presented by the following narratives: (i) mixed blessing: life‐saving treatment – meaningless exertion; (ii) compassion and understanding central amid use of complex machines; (iii) listening to the body; (iv) wanting to be seen as healthy; (v) dominance of technological thinking; and (vi) sustained work in maintaining the treatment. It is concluded that being dependent on technical breathing assistance during sleep, with or without oxygen, was a major life event for participants. The treatment was experienced as constraining and intrusive, particularly at the beginning, but concurrently it dramatically relieved difficulties for most participants. Regardless of its usefulness it provoked questions on purpose, indicating that the way to implement the treatment is crucial. Professionals need to pay close attention to how they introduce noninvasive ventilation technique, putting caring concern and respect for unique needs of patients and their families at the forefront.     

A case report of data monitoring experience: the nocturnal oxygen therapy trial

The monitoring of accumulating data in a clinical trial is a challenging endeavor, yet one that must be undertaken to fulfill the ethical responsibility to the participating subject. This paper, using the Nocturnal Oxygen Therapy Trial as an example, discusses three issues often faced by data monitoring committees. These are (1) the multiplicity of outcomes, (2) decisions about extension of the patient recruitment period in order to achieve specified sample size goals, and (3) problems in monitoring survival data with a lag in the reporting of events. The decision process can be quite complex and existing statistical methodology can at best serve as a guide in this decision process.     

Patients' experiences of long-term oxygen therapy

The aim of this study, which was undertaken in patients' homes in Sweden, was to describe patients' experiences in the self-management of continuous oxygen therapy and their view of managing their chronic disease. A phenomenological approach was used. Data were collected in interviews and analysis produced four categories. The findings show that the patients need help with relief for different physiological and psychological difficulties and from social isolation. The patients had insufficient resources for daily life. They were restricted to their homes, had mobility problems and were dependent upon a continuous life rhythm. Dependence upon another family member is therefore an important factor. But even with the presence of a significant other, social isolation is prevalent.     

Historical highlights of long-term oxygen therapy

The story of the development of oxygen and its role in mitigating the ravages of chronic stable hypoxemia have been fascinating. Today, over one million Americans receive home oxygen each day, usually for COPD, from one of the three available systems. The future requires less expensive, highly portable, and practical devices for use during all activities of daily living.     

Delivery systems for long-term oxygen therapy

Table 5 summarizes my current perspective on home oxygen delivery systems in the United States. As I already indicated, scoring for cost and labor may be very different in other countries. As noted, all things considered, today the most reasonable system for home oxygen therapy is the concentrator. Problems with FIO2, liter flow, and portability are clearly overshadowed by cost, labor, ease of use, and lack of potential hazard, as well as potential for future innovation. I would expect with future development that the concentrator will score higher on FIO2, liter flow, and portability. As a result of the anticipated large number of patients worldwide expected to require home oxygen therapy, ongoing improvement in this technology will be evident in the next few years.     

The history of long-term oxygen therapy.

Early investigators of oxygen therapy reported an overall clinical improvement in persons with chronic lung disease who received oxygen. Later American and British studies showed that oxygen therapy could decrease pulmonary vascular pressures and red cell mass in some patients with pulmonary hypertension and polycythemia secondary to severe hypoxemia. The British Research Council Study showed that survival rates were significantly higher in patients receiving 15 hours of oxygen than in those receiving no oxygen. The Nocturnal Oxygen Therapy Trial showed that survival rates for persons receiving continuous oxygen therapy has also been shown to improve exercise tolerance and neuropsychiatric function. Further advances in the administration of long-term oxygen therapy and studies in the criteria for its use are needed.     

Nonmedical hazards of long-term oxygen therapy.

Oxygen is neither explosive nor combustible, but because it does support combustion its potential fire hazards must be recognized. The principal fire hazards of long-term oxygen therapy are (1) the ignition potential of plastic delivery devices and (2) oxygen leaks (a) from high-pressure cylinders and cryogenic reservoirs into nearby combustible materials; (b) from oxygen concentrators, which are electrical devices; and (c) within piping systems. We found that with 100% oxygen a nasal cannula ignited and burned in about 2 minutes. With 60% oxygen the burning rate was slower, and with 40% the cannula did not ignite. We also studied various sizes of oxygen delivery tubing and found that tubing 3/16" or smaller with 40% oxygen flowing self-extinguished a flame. The safe use of oxygen in the home requires that patients and their families be knowledgeable about the hazards.     

A novel device for measuring long-term oxygen therapy adherence: a preliminary validation

INTRODUCTION: Current methods for measuring patient adherence to long-term oxygen therapy fail to measure the actual amount of time the patient is inhaling oxygen and the pattern of oxygen use within the day. We have developed a novel oxygen-adherence monitor to address these limitations, and this report introduces the monitor and provides preliminary data validating its use. METHODS: This battery-powered monitor attaches to the oxygen source and detects respiratory-related pressure fluctuations transmitted through the nasal cannula. The monitor takes a measurement over a 25-second period, at 4-min intervals. It detects and stores data on 4 different states that describe the patient's actual use of the oxygen source and nasal cannula: source-off/cannula-off, source-off/cannula-on, source-on/cannula-off, and source-on/cannula-on. We studied the monitor's performance with 10 patients with chronic obstructive pulmonary disease, during a directly-observed sequence of using and not using supplemental oxygen via nasal cannula, while sitting and walking. RESULTS: The monitor correctly detected 122 out of 129 measurements among all participants, yielding a 95\% detection accuracy. CONCLUSION: A monitor that objectively measures oxygen inhalation, rather than oxygen expenditure, may help improve the management of patients on long-term oxygen therapy.     

Long-term oxygen therapy vs long-term ventilatory assistance

The use of positive-pressure nasal ventilation in combination with LTOT in stable COPD patients with hypercapnic respiratory failure controls hypoventilation and improves daytime ABGs, sleep, and quality of life. Nasal ventilation in COPD is unlikely to produce benefit unless used with supplemental oxygen therapy at night. The patients who show the greatest reduction in overnight PaCO2 with ventilation are the patients most likely to benefit from long-term ventilatory support. Although there is now evidence for short-term benefit from NPPV in hypercapnic COPD, large multicenter studies with survival, exacerbations, and hospital admissions as the primary end points are required to evaluate longer-term effects of this potentially important intervention.     

Cost-effectiveness and efficacy in long-term oxygen therapy

Changes to the new home oxygen service have raised awareness among health professionals of the potential hazards and benefits of oxygen therapy. Annette Duck reviews the use of long-term oxygen therapy and highlights the importance of assessment in selecting both patients and suitable delivery systems.     

The demographics and economics of long-term oxygen therapy

Home oxygen therapy represents a scientifically validated and universally accepted therapeutic regimen for the treatment of chronic hypoxemia secondary to COPD. The clinical benefits of home oxygen, including a decrease in morbidity and often a concomitant increase in the quality of life have been repeatedly confirmed through rigorous worldwide trials, studies, and investigations. However, since home oxygen is an expensive treatment modality, important questions continue to be raised about the overall cost-benefit of the intervention. Such scrutiny is expected to continue, especially in the United States, as the entire issue of health care cost-containment remains atop the domestic political agenda. Providers of home oxygen therapy have traditionally realized quite favorable reimbursement for home oxygen equipment, especially for those patient-customers covered under the Medicare program. However, recent Medicare reimbursement reductions of more than 30% have raised serious questions about the ability of home oxygen providers, especially those with annual revenues less than $1 million, to sustain their historical high level of support services to home oxygen patient-customers. Of particular concern is the economic hardship of supplying portable oxygen, especially for those patient-customers with unusually high ambulatory needs. The use of oxygen-conserving devices is viewed by some as one strategy to better control the costs of supplying portable oxygen, although there are those who still question whether or not oxygen-conserving devices can effectively forestall arterial oxygen desaturation across the entire spectrum of ambulation. Given the evidence now being reported that compliance in using home oxygen as prescribed may well be much lower than originally believed, the time is probably right to revisit the role played by home oxygen providers in determining continuing need through the performance of periodic reassessments. Such reassessments, if designed according to prescribed and validated protocols and conducted by home respiratory therapists under orders of the prescribing physician, would be a valuable tool to ensure continued medical need and identifying noncompliance. This would help ensure that those needing and using home oxygen would continue to receive the benefit. At the same time, patient-customers who, for one reason or another, stop using their oxygen equipment despite repeated encouragement, would have the equipment removed. The net result would be that reimbursement dollars currently wasted on home oxygen equipment that is not being used could be reallocated for those patient-customers willing and able to use the equipment as prescribed.     

Effects of long-term oxygen therapy on mortality and morbidity

In general, based on the above studies of the effects of supplemental oxygen on reducing mortality and improving sleep and exercise function in certain patient groups, patients whose disease is stable on a full medical regimen with PaO2 < or = 55 mm Hg (SaO2 < or = 88%) should be considered for LTOT. Patients with PaO2 of 55-59 mm Hg with signs of tissue hypoxemia (i.e., cor pulmonale, polycythemia, impaired cognition) should also be considered for LTOT. Oxygen therapy should also be considered for those who desaturate during sleep or exercise. These guidelines have been adopted by Medicare as reimbursement criteria and have also been endorsed by the American Thoracic Society. Indications for LTOT endorsed by the American Thoracic Society and published in the "Standards for the Diagnosis and Care of Patients with COPD" are shown in Table 6. More research is required to investigate the use of supplemental oxygen in patients who suffer nocturnal desaturation but do not have signs of end organ dysfunction, those who have an improvement in dyspnea with supplemental oxygen, and in normoxemic patients with impaired exercise performance who improve while inspiring supplemental oxygen.     

A study of long-term oxygen therapy in Japan and other Asian countries.

In order to investigate the use of long-term oxygen therapy in Japan, I sent questionnaires to the national chronic disease hospitals and general hospitals that are known to frequently treat respiratory diseases. I found that 61% of the chronic disease hospitals that responded had patients receiving long-term oxygen therapy in the hospital, and 12% had patients receiving it at home. Of the general hospitals answering the questionnaire, 77% had inpatients on long-term oxygen and 39% had home patients receiving oxygen therapy. The majority of patients were on oxygen for treatment of tuberculosis, its sequelae, or obstructive lung diseases. The mean PaO2 for inpatients and outpatients on oxygen was 69 mm Hg and 65 mm Hg, respectively. The cannula is the most frequently used oxygen delivery appliance. Hospital piping systems are used for inpatients, and cylinders and concentrators are used by outpatients. Health insurance covers the cost of oxygen and equipment for hospitalized patients. Home oxygen and equipment are paid for by the patient himself, or at public expense. According to the results of my questionnaire, in Hong Kong long-term oxygen is administered in the hospital only. In Korea it is administered in the hospital and on rare occasion in the home. In Taiwan oxygen is not administered on a long-term basis.     

高压氧治疗一氧化碳中毒的护理体会

目的：探讨一氧化碳（CO）中毒患者高压氧治疗的护理措施。方法：对本院28例高压氧治疗的急性CO中毒患者的护理经验进行总结。结果：经过精心护理,28例中,治愈26例,好转2例。结论：早期高压氧治疗CO中毒,可以提高一氧化碳中毒患者的治愈率,减少或减轻迟发性脑病的发生,同时在整个高压氧治疗过程中做好每个环节的护理,是一氧化碳中毒患者救治成功的关键。     

Caring for patients with COPD on long-term oxygen therapy

Long-term oxygen therapy (LTOT) is becoming a mainstay of treatment for people with severe chronic obstructive pulmonary disease (COPD) in the community. This article provides an overview of the fundamental aspects of the therapy, measurement of blood gases and the equipment used in LTOT.     

Cognitive decline in patients with long-term domiciliary oxygen therapy

Cognitive and psycho-physiological condition in patients with long-term domiciliary oxygen therapy (DOT) remains uncertain. A cross sectional analysis was performed to investigate the age-related changes in cognitive and psycho-physiologic functions in patients with chronic respiratory failure receiving long-term DOT. Two expert practitioners visited the patient's home and examined them for analysis of cognitive function, emotional status, physical activity and degree of dyspneic sensation. One hundred and thirty-five patients completed the study. Control data from a cohort of 718 community dwellers were also included in this study. Male patients had significantly higher rates of chronic obstructive pulmonary disease (71% vs 47%, p = 0.001), lower values of forced expiratory volume in one second (FEV1.0) % (49.7 +/- 10.3 [standard deviation, S.D.] vs 66.0 +/- 7.5% predicted, p = 0.002) and higher Borg score, an indicator of dyspneic sensation, during daily exercise (3.2 +/- 0.8 [S.D.] vs 1.4 +/- 0.6, p = 0.01) compared with female patients. Linear regression analysis based on mean Mini-Mental State Examination scores, an indicator of cognitive function, showed that age-related cognitive decline was more pronounced in female patients than in female controls (-0.524/year, R2 = 0.426 vs -0.120/year, R2 = 0.027, p < 0.0001), while there was no significant difference between male patients and male controls (-0.156/year, R2 = 0.054, vs -0.077/year, R2 = 0.016, p = 0.231). These results demonstrate that age-related cognitive decline is more exaggerated in female patients receiving long-term DOT which should be taken into consideration in caring for patients with chronic respiratory failure.