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New study a departure from previous research
Case
An 85-year-old man with long-standing chronic obstructive pulmonary disease (COPD) has a witnessed aspiration event while undergoing an outpatient procedure requiring conscious sedation. He is admitted to the hospital for observation overnight. The next morning, he feels well, but his oxygen saturation dips to 85% with ambulation. He reports this is not new for him, but he vehemently does not want supplemental oxygen.
Background
Patients with COPD and severe resting hypoxemia – arterial oxygen partial pressure less than or equal to 55 mm Hg or peripheral capillary oxygen saturation (SpO2) less than or equal to 88% – commonly are prescribed supplemental oxygen. The evidence supporting this practice is limited to two small trials from the 1970s that showed a survival benefit of long-term oxygen therapy (LTOT) in this population,1,2 but these trials may not be generalizable to patients today.
For patients with COPD and mild to moderate resting hypoxemia (SpO2, 89%-93%) or patients with exercise-induced hypoxemia, LTOT has not been shown to improve survival, although it may improve symptoms of dyspnea, exercise tolerance, and other patient reported outcomes. Given the costs, risks, and burdens associated with LTOT, a high-quality clinical trial assessing the effects of LTOT on clinically meaningful outcomes, such as survival or hospitalization, in patients with COPD and moderate hypoxemia has been long overdue.
Overview of the data
The utility of long-term treatment with supplemental oxygen in patients with stable COPD and moderate resting or exercise-induced desaturation was examined by the Long-Term Oxygen Treatment Trial (LOTT) Research Group. Results were published in the New England Journal of Medicine in October 2016 in the article, “A Randomized Trial of Long-Term Oxygen for COPD with Moderate Desaturation.”3
The study was initially designed to test whether the use of supplemental oxygen would lead to longer time until death as compared with no supplemental oxygen in the subgroup of COPD patients with stable disease and moderate resting desaturation (defined as resting SpO2 of 89%-93%). However, because of an enrollment of only 34 patients after 7 months, the trial was redesigned to include exercise-induced desaturation (defined as SpO2 of greater than or equal to 80% for at least 5 minutes, and less than 90% for at least 10 seconds, on a 6-minute walk test) and the secondary outcome of all-cause hospitalization. Hospitalization for any cause was combined with mortality into a new composite primary outcome.
This study was a randomized, controlled trial which enrolled patients at a total of 14 regional clinical centers and their associated sites for a total of 42 centers in the United States. The experimental arm consisted of a long term supplemental oxygen group, and the control group did not receive long term supplemental oxygen. Patients were assigned to groups in a 1:1 ratio and the study was not blinded. Patients with moderate resting desaturation were prescribed 24 hour oxygen at 2 L/min, and patients with moderate exercise-induced desaturation were prescribed oxygen at 2 L/min during exercise and sleep only. The primary outcome was a composite outcome of time until death or time until first hospitalization for any cause. There were multiple secondary outcomes, including incidence of COPD exacerbation, incidence of severe resting desaturation and severe exercise-induced desaturation, quality of life, sleep quality, depression and anxiety, adherence to regimen, 6-minute walk distance, spirometric measurements, risk of cardiovascular disease, and neurocognitive function.
Data were gathered via yearly visits, biannual telephone interviews, and questionnaires mailed at 4 months and 16 months. Adherence was assessed by inquiring about oxygen use every 4 months. If patients in the supplemental oxygen group used stationary oxygen concentrators, logs of meter readings were kept as well. The necessary final sample size was calculated using a time to composite event survival model with the use of the log-rank test statistic.
A total of 738 patients were enrolled in the trial between January 2009 and September 2015 and were followed for 1-6 years. A total of 97% of participants had at least 1 year of follow-up. Out of the 738 randomized patients, 133 (18%) had only resting desaturations, 319 (43%) had only exercise-induced desaturations, and 286 (39%) had both resting and exercise-induced desaturations. Baseline characteristics including age, sex, race, smoking status, quality of life scores, resting SpO2, and nadir SpO2 during the 6-minute walk test were similar between the two groups. The only significant difference noted by the authors between the two groups was a lower BODE (body mass index, airflow obstruction, dyspnea, and exercise) index, which was lower in the group with no supplemental oxygen.
In the time-to-event analysis, there was no significant difference between the two groups in the time to death or first hospitalization (hazard ratio, 0.94; 95% confidence interval, 0.79-1.12; P = .52). There were no significant differences in the rates of all hospitalizations (rate ratio, 1.01; 95% CI, 0.91-1.13), COPD exacerbations (RR 1.08; 95% CI, 0.98-1.19), and COPD related hospitalizations (RR, 0.99; 95% CI, 0.83-1.17). There were also no differences between the experimental and control groups in quality of life, lung function, and 6-minute walk distance. There were no significant differences in the subgroups classified by desaturation profile, sex, race, nadir SpO2 during the 6-minute walk test, and forced expiratory volume in 1 second.
The findings in this study show that, in the subgroup of chronic obstructive pulmonary disease patients with stable COPD and moderate resting or exercise-induced desaturation, supplemental oxygen did not affect the time to death or first hospitalization, time to death, time to first hospitalization, time to first COPD exacerbation, time to first hospitalization for a COPD exacerbation, rate of all hospitalizations, rate of all COPD exacerbations, or changes in metrics surrounding quality of life, anxiety/depression, or functional status. This supports earlier studies that demonstrated that long-term treatment with oxygen does not result in longer survival than does no long-term treatment with oxygen in patients with COPD and resting SpO2 of more than 88%.
The results of this study are a departure from previous studies that had shown improved mortality in patients with COPD and severe desaturation who were treated with LTOT. The authors hypothesized that this may have been caused by physiological effects of oxygen saturation on pulmonary vasoconstriction, release of mediators, and ventilator drive, which occur at an O2 saturation of 88% or less and may be more significant in patients with chronic hypoxemia. This trial also contrasted previous studies that had shown that oxygen therapy may reduce dyspnea in COPD patients with mild or no hypoxia because the LOTT trial showed no improvement in quality of life, anxiety, and depression measures in patients treated with long-term oxygen as compared with those treated with no oxygen.
Some limitations of the study included the absence of highly symptomatic patients or patients who the providers believed were too ill to participate, the effect of the unblinded nature of the study on outcomes that were patient reported, the lack of assessment of immediate effects of oxygen on exercise performance or symptoms, possible variability in amount of oxygen delivered, and the fact that patients may have overestimated their oxygen use.
In patients with stable COPD and moderate resting or exercise induced desaturation, long-term supplemental oxygen did not provide any benefit in regard to time until death or first hospitalization or any of the other measured outcomes.
Application of data to the case
Our patient has stable COPD and had only moderate exercise-induced desaturation. Long-term supplemental oxygen would not produce a benefit for him.
This study shows us that it would not increase his survival at this point; however, if he were to have worsening exercise-induced or new resting desaturation at some point in the future, supplemental oxygen would then be beneficial. At this point supplemental oxygen would not even affect his rate of hospitalization for COPD- or non-COPD–related reasons. Perhaps most importantly, adding oxygen therapy would not affect his overall quality of life, including his functional status and mood.
Bottom line
The addition of supplemental oxygen is not helpful for patients with COPD who have chronic stable moderate hypoxia.
Dr. Farber is a medical instructor in the Duke University Health System in Durham, N.C. Dr. Sata is a medical instructor in the Duke University Hospital. Dr. Wachter is an assistant professor of medicine at Duke University. Dr. Sharma is associate medical director for clinical education in hospital medicine at Duke Regional Hospital and an assistant professor of medicine at Duke University.
References
1. Nocturnal Oxygen Therapy Trial Group. Continuous or nocturnal oxygen therapy in hypoxemic chronic obstructive lung disease: A clinical trial. Ann Intern Med. 1980 Sep;93(3):391-8.
2. Medical Research Council Working Party. Long term domiciliary oxygen therapy in chronic hypoxic cor pulmonale complicating chronic bronchitis and emphysema: Report of the Medical Research Council Working Party. Lancet 1981 Mar 28;1(8222):681-6.
3. Long-term oxygen treatment trial research group et al. A randomized trial of long-term oxygen for COPD with moderate desaturation. N Engl J Med. 2016 Oct 27;375(17):1617-27.
Additional reading
Stoller JK et al. Oxygen therapy for patients with COPD: Current evidence and the Long-term Oxygen Treatment Trial. Chest. 2010 July;138:179-87.
Qaseem A et al. Diagnosis and management of stable chronic obstructive pulmonary disease: A clinical practice guideline update from the American College of Physicians, American College of Chest Physicians, American Thoracic Society, and European Respiratory Society. Ann Intern Med. 2011 Aug 2;155(3):179-91.
Ameer F et al. Ambulatory oxygen for people with chronic obstructive pulmonary disease who are not hypoxaemic at rest. Cochrane Database Syst Rev. 2014 Jun 24;(6):CD000238.
Vestbo J et al. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary. Am J Respir Crit Care Med. 2013 Feb 15;187(4):347-65.
Quiz: Does this patient need oxygen?
You are caring for a 72-year-old man with stable COPD who was admitted for cellulitis. He is improving clinically on appropriate antibiotics, and he has been stable on room air every time you examine him. The nurse pages you on the day of discharge – a Sunday – informing you that his oxygen saturation dropped to 88% while he was walking the halls this morning. She asks whether he needs to stay in the hospital so you can arrange home supplemental oxygen therapy. What should you do?
A. Keep him in the hospital until you can arrange home oxygen therapy.
B. Discharge him home Sunday but have the oxygen company go out to his house first thing on Monday.
C. Discharge him home without supplemental oxygen therapy.
D. Check an arterial blood gas to help decide if you should set up oxygen therapy.
The answer is C. He meets the description of stable COPD with mild to moderate exercise-induced desaturation. The LOTT trial supports our clinical decision that he would not benefit from supplemental oxygen therapy at this point.
Key Points
- Long-term oxygen therapy (LTOT) is beneficial in patients with COPD and severe resting hypoxemia (arterial oxygen partial pressure ≤ 55 mm Hg or SpO2 ≤ 88%) and should be prescribed to improve survival in this population.
- Patients with COPD and mild to moderate resting hypoxemia or exercised-induced hypoxemia should not be routinely prescribed LTOT given the associated costs, risks, and burdens and the lack of evidence of benefit.
New study a departure from previous research
New study a departure from previous research
Case
An 85-year-old man with long-standing chronic obstructive pulmonary disease (COPD) has a witnessed aspiration event while undergoing an outpatient procedure requiring conscious sedation. He is admitted to the hospital for observation overnight. The next morning, he feels well, but his oxygen saturation dips to 85% with ambulation. He reports this is not new for him, but he vehemently does not want supplemental oxygen.
Background
Patients with COPD and severe resting hypoxemia – arterial oxygen partial pressure less than or equal to 55 mm Hg or peripheral capillary oxygen saturation (SpO2) less than or equal to 88% – commonly are prescribed supplemental oxygen. The evidence supporting this practice is limited to two small trials from the 1970s that showed a survival benefit of long-term oxygen therapy (LTOT) in this population,1,2 but these trials may not be generalizable to patients today.
For patients with COPD and mild to moderate resting hypoxemia (SpO2, 89%-93%) or patients with exercise-induced hypoxemia, LTOT has not been shown to improve survival, although it may improve symptoms of dyspnea, exercise tolerance, and other patient reported outcomes. Given the costs, risks, and burdens associated with LTOT, a high-quality clinical trial assessing the effects of LTOT on clinically meaningful outcomes, such as survival or hospitalization, in patients with COPD and moderate hypoxemia has been long overdue.
Overview of the data
The utility of long-term treatment with supplemental oxygen in patients with stable COPD and moderate resting or exercise-induced desaturation was examined by the Long-Term Oxygen Treatment Trial (LOTT) Research Group. Results were published in the New England Journal of Medicine in October 2016 in the article, “A Randomized Trial of Long-Term Oxygen for COPD with Moderate Desaturation.”3
The study was initially designed to test whether the use of supplemental oxygen would lead to longer time until death as compared with no supplemental oxygen in the subgroup of COPD patients with stable disease and moderate resting desaturation (defined as resting SpO2 of 89%-93%). However, because of an enrollment of only 34 patients after 7 months, the trial was redesigned to include exercise-induced desaturation (defined as SpO2 of greater than or equal to 80% for at least 5 minutes, and less than 90% for at least 10 seconds, on a 6-minute walk test) and the secondary outcome of all-cause hospitalization. Hospitalization for any cause was combined with mortality into a new composite primary outcome.
This study was a randomized, controlled trial which enrolled patients at a total of 14 regional clinical centers and their associated sites for a total of 42 centers in the United States. The experimental arm consisted of a long term supplemental oxygen group, and the control group did not receive long term supplemental oxygen. Patients were assigned to groups in a 1:1 ratio and the study was not blinded. Patients with moderate resting desaturation were prescribed 24 hour oxygen at 2 L/min, and patients with moderate exercise-induced desaturation were prescribed oxygen at 2 L/min during exercise and sleep only. The primary outcome was a composite outcome of time until death or time until first hospitalization for any cause. There were multiple secondary outcomes, including incidence of COPD exacerbation, incidence of severe resting desaturation and severe exercise-induced desaturation, quality of life, sleep quality, depression and anxiety, adherence to regimen, 6-minute walk distance, spirometric measurements, risk of cardiovascular disease, and neurocognitive function.
Data were gathered via yearly visits, biannual telephone interviews, and questionnaires mailed at 4 months and 16 months. Adherence was assessed by inquiring about oxygen use every 4 months. If patients in the supplemental oxygen group used stationary oxygen concentrators, logs of meter readings were kept as well. The necessary final sample size was calculated using a time to composite event survival model with the use of the log-rank test statistic.
A total of 738 patients were enrolled in the trial between January 2009 and September 2015 and were followed for 1-6 years. A total of 97% of participants had at least 1 year of follow-up. Out of the 738 randomized patients, 133 (18%) had only resting desaturations, 319 (43%) had only exercise-induced desaturations, and 286 (39%) had both resting and exercise-induced desaturations. Baseline characteristics including age, sex, race, smoking status, quality of life scores, resting SpO2, and nadir SpO2 during the 6-minute walk test were similar between the two groups. The only significant difference noted by the authors between the two groups was a lower BODE (body mass index, airflow obstruction, dyspnea, and exercise) index, which was lower in the group with no supplemental oxygen.
In the time-to-event analysis, there was no significant difference between the two groups in the time to death or first hospitalization (hazard ratio, 0.94; 95% confidence interval, 0.79-1.12; P = .52). There were no significant differences in the rates of all hospitalizations (rate ratio, 1.01; 95% CI, 0.91-1.13), COPD exacerbations (RR 1.08; 95% CI, 0.98-1.19), and COPD related hospitalizations (RR, 0.99; 95% CI, 0.83-1.17). There were also no differences between the experimental and control groups in quality of life, lung function, and 6-minute walk distance. There were no significant differences in the subgroups classified by desaturation profile, sex, race, nadir SpO2 during the 6-minute walk test, and forced expiratory volume in 1 second.
The findings in this study show that, in the subgroup of chronic obstructive pulmonary disease patients with stable COPD and moderate resting or exercise-induced desaturation, supplemental oxygen did not affect the time to death or first hospitalization, time to death, time to first hospitalization, time to first COPD exacerbation, time to first hospitalization for a COPD exacerbation, rate of all hospitalizations, rate of all COPD exacerbations, or changes in metrics surrounding quality of life, anxiety/depression, or functional status. This supports earlier studies that demonstrated that long-term treatment with oxygen does not result in longer survival than does no long-term treatment with oxygen in patients with COPD and resting SpO2 of more than 88%.
The results of this study are a departure from previous studies that had shown improved mortality in patients with COPD and severe desaturation who were treated with LTOT. The authors hypothesized that this may have been caused by physiological effects of oxygen saturation on pulmonary vasoconstriction, release of mediators, and ventilator drive, which occur at an O2 saturation of 88% or less and may be more significant in patients with chronic hypoxemia. This trial also contrasted previous studies that had shown that oxygen therapy may reduce dyspnea in COPD patients with mild or no hypoxia because the LOTT trial showed no improvement in quality of life, anxiety, and depression measures in patients treated with long-term oxygen as compared with those treated with no oxygen.
Some limitations of the study included the absence of highly symptomatic patients or patients who the providers believed were too ill to participate, the effect of the unblinded nature of the study on outcomes that were patient reported, the lack of assessment of immediate effects of oxygen on exercise performance or symptoms, possible variability in amount of oxygen delivered, and the fact that patients may have overestimated their oxygen use.
In patients with stable COPD and moderate resting or exercise induced desaturation, long-term supplemental oxygen did not provide any benefit in regard to time until death or first hospitalization or any of the other measured outcomes.
Application of data to the case
Our patient has stable COPD and had only moderate exercise-induced desaturation. Long-term supplemental oxygen would not produce a benefit for him.
This study shows us that it would not increase his survival at this point; however, if he were to have worsening exercise-induced or new resting desaturation at some point in the future, supplemental oxygen would then be beneficial. At this point supplemental oxygen would not even affect his rate of hospitalization for COPD- or non-COPD–related reasons. Perhaps most importantly, adding oxygen therapy would not affect his overall quality of life, including his functional status and mood.
Bottom line
The addition of supplemental oxygen is not helpful for patients with COPD who have chronic stable moderate hypoxia.
Dr. Farber is a medical instructor in the Duke University Health System in Durham, N.C. Dr. Sata is a medical instructor in the Duke University Hospital. Dr. Wachter is an assistant professor of medicine at Duke University. Dr. Sharma is associate medical director for clinical education in hospital medicine at Duke Regional Hospital and an assistant professor of medicine at Duke University.
References
1. Nocturnal Oxygen Therapy Trial Group. Continuous or nocturnal oxygen therapy in hypoxemic chronic obstructive lung disease: A clinical trial. Ann Intern Med. 1980 Sep;93(3):391-8.
2. Medical Research Council Working Party. Long term domiciliary oxygen therapy in chronic hypoxic cor pulmonale complicating chronic bronchitis and emphysema: Report of the Medical Research Council Working Party. Lancet 1981 Mar 28;1(8222):681-6.
3. Long-term oxygen treatment trial research group et al. A randomized trial of long-term oxygen for COPD with moderate desaturation. N Engl J Med. 2016 Oct 27;375(17):1617-27.
Additional reading
Stoller JK et al. Oxygen therapy for patients with COPD: Current evidence and the Long-term Oxygen Treatment Trial. Chest. 2010 July;138:179-87.
Qaseem A et al. Diagnosis and management of stable chronic obstructive pulmonary disease: A clinical practice guideline update from the American College of Physicians, American College of Chest Physicians, American Thoracic Society, and European Respiratory Society. Ann Intern Med. 2011 Aug 2;155(3):179-91.
Ameer F et al. Ambulatory oxygen for people with chronic obstructive pulmonary disease who are not hypoxaemic at rest. Cochrane Database Syst Rev. 2014 Jun 24;(6):CD000238.
Vestbo J et al. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary. Am J Respir Crit Care Med. 2013 Feb 15;187(4):347-65.
Quiz: Does this patient need oxygen?
You are caring for a 72-year-old man with stable COPD who was admitted for cellulitis. He is improving clinically on appropriate antibiotics, and he has been stable on room air every time you examine him. The nurse pages you on the day of discharge – a Sunday – informing you that his oxygen saturation dropped to 88% while he was walking the halls this morning. She asks whether he needs to stay in the hospital so you can arrange home supplemental oxygen therapy. What should you do?
A. Keep him in the hospital until you can arrange home oxygen therapy.
B. Discharge him home Sunday but have the oxygen company go out to his house first thing on Monday.
C. Discharge him home without supplemental oxygen therapy.
D. Check an arterial blood gas to help decide if you should set up oxygen therapy.
The answer is C. He meets the description of stable COPD with mild to moderate exercise-induced desaturation. The LOTT trial supports our clinical decision that he would not benefit from supplemental oxygen therapy at this point.
Key Points
- Long-term oxygen therapy (LTOT) is beneficial in patients with COPD and severe resting hypoxemia (arterial oxygen partial pressure ≤ 55 mm Hg or SpO2 ≤ 88%) and should be prescribed to improve survival in this population.
- Patients with COPD and mild to moderate resting hypoxemia or exercised-induced hypoxemia should not be routinely prescribed LTOT given the associated costs, risks, and burdens and the lack of evidence of benefit.
Case
An 85-year-old man with long-standing chronic obstructive pulmonary disease (COPD) has a witnessed aspiration event while undergoing an outpatient procedure requiring conscious sedation. He is admitted to the hospital for observation overnight. The next morning, he feels well, but his oxygen saturation dips to 85% with ambulation. He reports this is not new for him, but he vehemently does not want supplemental oxygen.
Background
Patients with COPD and severe resting hypoxemia – arterial oxygen partial pressure less than or equal to 55 mm Hg or peripheral capillary oxygen saturation (SpO2) less than or equal to 88% – commonly are prescribed supplemental oxygen. The evidence supporting this practice is limited to two small trials from the 1970s that showed a survival benefit of long-term oxygen therapy (LTOT) in this population,1,2 but these trials may not be generalizable to patients today.
For patients with COPD and mild to moderate resting hypoxemia (SpO2, 89%-93%) or patients with exercise-induced hypoxemia, LTOT has not been shown to improve survival, although it may improve symptoms of dyspnea, exercise tolerance, and other patient reported outcomes. Given the costs, risks, and burdens associated with LTOT, a high-quality clinical trial assessing the effects of LTOT on clinically meaningful outcomes, such as survival or hospitalization, in patients with COPD and moderate hypoxemia has been long overdue.
Overview of the data
The utility of long-term treatment with supplemental oxygen in patients with stable COPD and moderate resting or exercise-induced desaturation was examined by the Long-Term Oxygen Treatment Trial (LOTT) Research Group. Results were published in the New England Journal of Medicine in October 2016 in the article, “A Randomized Trial of Long-Term Oxygen for COPD with Moderate Desaturation.”3
The study was initially designed to test whether the use of supplemental oxygen would lead to longer time until death as compared with no supplemental oxygen in the subgroup of COPD patients with stable disease and moderate resting desaturation (defined as resting SpO2 of 89%-93%). However, because of an enrollment of only 34 patients after 7 months, the trial was redesigned to include exercise-induced desaturation (defined as SpO2 of greater than or equal to 80% for at least 5 minutes, and less than 90% for at least 10 seconds, on a 6-minute walk test) and the secondary outcome of all-cause hospitalization. Hospitalization for any cause was combined with mortality into a new composite primary outcome.
This study was a randomized, controlled trial which enrolled patients at a total of 14 regional clinical centers and their associated sites for a total of 42 centers in the United States. The experimental arm consisted of a long term supplemental oxygen group, and the control group did not receive long term supplemental oxygen. Patients were assigned to groups in a 1:1 ratio and the study was not blinded. Patients with moderate resting desaturation were prescribed 24 hour oxygen at 2 L/min, and patients with moderate exercise-induced desaturation were prescribed oxygen at 2 L/min during exercise and sleep only. The primary outcome was a composite outcome of time until death or time until first hospitalization for any cause. There were multiple secondary outcomes, including incidence of COPD exacerbation, incidence of severe resting desaturation and severe exercise-induced desaturation, quality of life, sleep quality, depression and anxiety, adherence to regimen, 6-minute walk distance, spirometric measurements, risk of cardiovascular disease, and neurocognitive function.
Data were gathered via yearly visits, biannual telephone interviews, and questionnaires mailed at 4 months and 16 months. Adherence was assessed by inquiring about oxygen use every 4 months. If patients in the supplemental oxygen group used stationary oxygen concentrators, logs of meter readings were kept as well. The necessary final sample size was calculated using a time to composite event survival model with the use of the log-rank test statistic.
A total of 738 patients were enrolled in the trial between January 2009 and September 2015 and were followed for 1-6 years. A total of 97% of participants had at least 1 year of follow-up. Out of the 738 randomized patients, 133 (18%) had only resting desaturations, 319 (43%) had only exercise-induced desaturations, and 286 (39%) had both resting and exercise-induced desaturations. Baseline characteristics including age, sex, race, smoking status, quality of life scores, resting SpO2, and nadir SpO2 during the 6-minute walk test were similar between the two groups. The only significant difference noted by the authors between the two groups was a lower BODE (body mass index, airflow obstruction, dyspnea, and exercise) index, which was lower in the group with no supplemental oxygen.
In the time-to-event analysis, there was no significant difference between the two groups in the time to death or first hospitalization (hazard ratio, 0.94; 95% confidence interval, 0.79-1.12; P = .52). There were no significant differences in the rates of all hospitalizations (rate ratio, 1.01; 95% CI, 0.91-1.13), COPD exacerbations (RR 1.08; 95% CI, 0.98-1.19), and COPD related hospitalizations (RR, 0.99; 95% CI, 0.83-1.17). There were also no differences between the experimental and control groups in quality of life, lung function, and 6-minute walk distance. There were no significant differences in the subgroups classified by desaturation profile, sex, race, nadir SpO2 during the 6-minute walk test, and forced expiratory volume in 1 second.
The findings in this study show that, in the subgroup of chronic obstructive pulmonary disease patients with stable COPD and moderate resting or exercise-induced desaturation, supplemental oxygen did not affect the time to death or first hospitalization, time to death, time to first hospitalization, time to first COPD exacerbation, time to first hospitalization for a COPD exacerbation, rate of all hospitalizations, rate of all COPD exacerbations, or changes in metrics surrounding quality of life, anxiety/depression, or functional status. This supports earlier studies that demonstrated that long-term treatment with oxygen does not result in longer survival than does no long-term treatment with oxygen in patients with COPD and resting SpO2 of more than 88%.
The results of this study are a departure from previous studies that had shown improved mortality in patients with COPD and severe desaturation who were treated with LTOT. The authors hypothesized that this may have been caused by physiological effects of oxygen saturation on pulmonary vasoconstriction, release of mediators, and ventilator drive, which occur at an O2 saturation of 88% or less and may be more significant in patients with chronic hypoxemia. This trial also contrasted previous studies that had shown that oxygen therapy may reduce dyspnea in COPD patients with mild or no hypoxia because the LOTT trial showed no improvement in quality of life, anxiety, and depression measures in patients treated with long-term oxygen as compared with those treated with no oxygen.
Some limitations of the study included the absence of highly symptomatic patients or patients who the providers believed were too ill to participate, the effect of the unblinded nature of the study on outcomes that were patient reported, the lack of assessment of immediate effects of oxygen on exercise performance or symptoms, possible variability in amount of oxygen delivered, and the fact that patients may have overestimated their oxygen use.
In patients with stable COPD and moderate resting or exercise induced desaturation, long-term supplemental oxygen did not provide any benefit in regard to time until death or first hospitalization or any of the other measured outcomes.
Application of data to the case
Our patient has stable COPD and had only moderate exercise-induced desaturation. Long-term supplemental oxygen would not produce a benefit for him.
This study shows us that it would not increase his survival at this point; however, if he were to have worsening exercise-induced or new resting desaturation at some point in the future, supplemental oxygen would then be beneficial. At this point supplemental oxygen would not even affect his rate of hospitalization for COPD- or non-COPD–related reasons. Perhaps most importantly, adding oxygen therapy would not affect his overall quality of life, including his functional status and mood.
Bottom line
The addition of supplemental oxygen is not helpful for patients with COPD who have chronic stable moderate hypoxia.
Dr. Farber is a medical instructor in the Duke University Health System in Durham, N.C. Dr. Sata is a medical instructor in the Duke University Hospital. Dr. Wachter is an assistant professor of medicine at Duke University. Dr. Sharma is associate medical director for clinical education in hospital medicine at Duke Regional Hospital and an assistant professor of medicine at Duke University.
References
1. Nocturnal Oxygen Therapy Trial Group. Continuous or nocturnal oxygen therapy in hypoxemic chronic obstructive lung disease: A clinical trial. Ann Intern Med. 1980 Sep;93(3):391-8.
2. Medical Research Council Working Party. Long term domiciliary oxygen therapy in chronic hypoxic cor pulmonale complicating chronic bronchitis and emphysema: Report of the Medical Research Council Working Party. Lancet 1981 Mar 28;1(8222):681-6.
3. Long-term oxygen treatment trial research group et al. A randomized trial of long-term oxygen for COPD with moderate desaturation. N Engl J Med. 2016 Oct 27;375(17):1617-27.
Additional reading
Stoller JK et al. Oxygen therapy for patients with COPD: Current evidence and the Long-term Oxygen Treatment Trial. Chest. 2010 July;138:179-87.
Qaseem A et al. Diagnosis and management of stable chronic obstructive pulmonary disease: A clinical practice guideline update from the American College of Physicians, American College of Chest Physicians, American Thoracic Society, and European Respiratory Society. Ann Intern Med. 2011 Aug 2;155(3):179-91.
Ameer F et al. Ambulatory oxygen for people with chronic obstructive pulmonary disease who are not hypoxaemic at rest. Cochrane Database Syst Rev. 2014 Jun 24;(6):CD000238.
Vestbo J et al. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary. Am J Respir Crit Care Med. 2013 Feb 15;187(4):347-65.
Quiz: Does this patient need oxygen?
You are caring for a 72-year-old man with stable COPD who was admitted for cellulitis. He is improving clinically on appropriate antibiotics, and he has been stable on room air every time you examine him. The nurse pages you on the day of discharge – a Sunday – informing you that his oxygen saturation dropped to 88% while he was walking the halls this morning. She asks whether he needs to stay in the hospital so you can arrange home supplemental oxygen therapy. What should you do?
A. Keep him in the hospital until you can arrange home oxygen therapy.
B. Discharge him home Sunday but have the oxygen company go out to his house first thing on Monday.
C. Discharge him home without supplemental oxygen therapy.
D. Check an arterial blood gas to help decide if you should set up oxygen therapy.
The answer is C. He meets the description of stable COPD with mild to moderate exercise-induced desaturation. The LOTT trial supports our clinical decision that he would not benefit from supplemental oxygen therapy at this point.
Key Points
- Long-term oxygen therapy (LTOT) is beneficial in patients with COPD and severe resting hypoxemia (arterial oxygen partial pressure ≤ 55 mm Hg or SpO2 ≤ 88%) and should be prescribed to improve survival in this population.
- Patients with COPD and mild to moderate resting hypoxemia or exercised-induced hypoxemia should not be routinely prescribed LTOT given the associated costs, risks, and burdens and the lack of evidence of benefit.