Hypoxemic Chronic Obstructive Pulmonary Disease Research Articles

Attention, memory, and executive functioning in hypoxemic chronic obstructive pulmonary disease patients

Background: Chronic obstructive pulmonary disease (COPD) is characterized by chronic airflow obstruction and is one of the leading causes of death globally. The changes in pulmonary functions in COPD are irreversible with devastating consequences. Cognitive functioning in COPD patients is often found impaired and postulated to happen due to hypoxemia, i.e., oxygen deprivation to the brain. An impaired cognitive functioning can have direct impact on functional abilities as well as quality of life of patients and could be a vital treatment goal. The study aimed to explore the attention, memory, and executive functioning in hypoxemic COPD patients in backdrop of dearth of studies from India. Materials and Methods: Using purposive sampling, 30 patients with COPD, having mild-to-moderate level of illness severity, and having minimum illness for duration of 5 years were compared with 30 healthy controls. Participants were assessed for cognitive functioning in the domains of sustained attention, processing and psychomotor speed, working memory, verbal learning, and memory and executive functions using neuropsychological tests, namely, Digit Symbol Substitution Test, Trial Making Test, Verbal N Back Test, Rey's Audio Visual Learning Test, Controlled Oral Word Association Test, Animal Naming Test, Stroop Neuropsychological Test, and Modified Wisconsin Card Sorting Test. Results: Findings suggest significant differences between COPD patients and healthy controls over processing and psychomotor speed, working memory, memory, learning, and executive functioning. Conclusion: In addition to pulmonary distress, COPD patients also have compromised cognitive functions affecting overall daily functioning and quality of life. Understanding the nature of decline in cognitive functions could be vital in improving daily psychosocial functioning of the patients with COPD, and the exploration could help professionals in intervention of specific cognitive functioning.

Korean physician prescription patterns for home oxygen therapy in chronic obstructive pulmonary disease patients.

Background/AimsHypoxemia in chronic obstructive pulmonary disease (COPD) leads to reduced ability to exercise, decreased quality of life, and, eventually, increased mortality. Home oxygen therapy in patients with severe COPD reduces distress symptoms and mortality rates. However, there have been few studies on physicians’ prescription behavior toward home oxygen therapy. Therefore, we investigated the respiratory specialists’ perspective on home oxygen therapy.MethodsIn this cross-sectional, study, a questionnaire was completed by 30 pulmonary specialists who worked in tertiary hospitals and prescribed home oxygen therapy. The questionnaire consisted of 28 items, including 15 items on oxygen prescription for outpatients, four for inpatients, and nine on service improvement.ResultsAll physicians were prescribing less than 2 L/min of oxygen for either 24 (n = 10, 33.3%) or 15 hours (n = 9, 30.3%). All (n = 30) used pulse oximetry, 26 (86.7%) analyzed arterial blood gas. Thirteen physicians had imposed restrictions and recommended oxygen use only during exercise or sleep. Sixteen (53.3%) physicians were educating their patients about home oxygen therapy. Furthermore, physicians prescribed home oxygen to patients that did not fit the typical criteria for long-term oxygen therapy, with 30 prescribing it for acute relief and 17 for patients with borderline hypoxemia.ConclusionsThis study identified the prescription pattern of home oxygen therapy in Korea. Respiratory physicians prescribe home oxygen therapy to hypoxemic COPD patients for at least 15 hours/day, and at a rate of less than 2 L/min. More research is needed to provide evidence for establishing policies on oxygen therapy in COPD patients.

A FROSTY CASE OF FACIAL FROSTBITE IN THE FACE OF LIQUID OXYGEN

SESSION TITLE: Medical Student/Resident Respiratory Care SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Long-term oxygen therapy (LTOT) is used by more than 1.5 million US adults and has been shown to both decrease mortality and increase quality of life in hypoxemic COPD. Many mechanical injuries involving LTOT are user directed and occur when a heat source ignites purified oxygen (O2), such as cigarettes. Here, we report the first English case of frostbite injury to the face due a malfunctioning liquid oxygen (LOx) canister. CASE PRESENTATION: Our patient was an 80-year-old female with a significant past medical history of COPD who presented to the emergency room with epistaxis and mucopurulent rhinorrhea after her nasal cannula (NC) was found frozen to her face. It was reported that LOx traveled up her NC. On physical exam, she had multiple second and third-degree burns on her nose, throat, lips, cheeks, and neck. She was placed on an open non-rebreather mask, and her facial frostbite was empirically treated with vancomycin and ampicillin-sulbactam for fourteen days to prevent cavernous sinus thrombosis. Otolaryngology was consulted to debride her wounds and open her nasal passages. A PEG tube was required to maintain her nutritional status. Towards the end of her fourteen-day hospital stay, her burns had shrunk and become more demarcated. However, the patient became febrile and complained of a painful headache. A CT of her head revealed acute sphenoid sinusitis, for which she was discharged on amoxicillin-clavulanic acid and doxycycline for an additional seven days. DISCUSSION: A cryogenic LOx tank consists of two vessels: an inner chamber where the LOx is kept cool by an insulated area around it from which air is removed, and an outer chamber which consists of a vaporizer that converts LOx into a gaseous state [1]. O2 is cooled to less than -183°C to achieve its liquid form for storage and transportation efficiency [1], as one liter of LOx offers 860 liters of gaseous O2. This large liquid-to-gas expansion ratio can generate an enormous amount of pressure. One case study describing frostbite injury due to a compressed gaseous O2 tank postulated that it was caused by pressure regulation failure, and showed that increasing amounts of pressure led to a significant decrease in temperature of the compressed air [1]. Similarly, we believe that our patient’s LOx pressure release system malfunctioned, driving a large outflow of unconverted LOx to penetrate the vapor chamber, enter her NC, and freeze her face. Unlike typical frostbite, burns involving LOx occur over seconds and are more likely to infiltrate underlying tissue compared to thermal burns. Removal of the LOx and rewarming as soon as possible should be done to prevent further damage [2]. CONCLUSIONS: The broad utilization of LTOT can invite extremely rare cases of hardware malfunction that may cause severe injury. Safety protocols and schedules should be strictly followed for refilling and handling O2 storage equipment. Reference #1: Jabbour, N., Heman-Ackah, S. E., Day, A. T., & Odland, R. (2011). Severe nasal frostbite injury from nasal cannula supplemental oxygen malfunction. American Journal of Otolaryngology, 32(4), 349–352. doi:10.1016/j.amjoto.2010.03.009 Reference #2: Uygur, F., Sever, C., & Noyan, N. (2009). Frostbite Burns Caused by Liquid Oxygen. Journal of Burn Care & Research, 30(2), 358–361. doi:10.1097/bcr.0b013e318198a769 DISCLOSURES: No relevant relationships by Olson Knight, source=Web Response No relevant relationships by munir shah, source=Web Response No relevant relationships by Parth Shah, source=Web Response No relevant relationships by Krupa Solanki, source=Web Response

High-Flow Oxygen Therapy During Exercise Training in Patients With Chronic Obstructive Pulmonary Disease and Chronic Hypoxemia: A Multicenter Randomized Controlled Trial.

The study aimed to evaluate whether high-flow oxygen therapy (HFOT) during training was more effective than oxygen in improving exercise capacity in hypoxemic chronic obstructive pulmonary disease (COPD). A total of 171 patients with COPD and chronic hypoxemia were consecutively recruited in 8 rehabilitation hospitals in a randomized controlled trial. Cycle-ergometer exercise training was used in 20 supervised sessions at iso inspiratory oxygen fraction in both groups. Pre- and post-training endurance time (Tlim), 6-minute walking distance (6MWD), respiratory and limb muscle strength, arterial blood gases, Barthel Index, Barthel Dyspnea Index, COPD Assessment Test, Maugeri Respiratory Failure questionnaire, and patient satisfaction were evaluated. Due to 15.4% and 24.1% dropout rates, 71 and 66 patients were analyzed in HFOT and Venturi mask (V-mask) groups, respectively. Exercise capacity significantly improved after training in both groups with similar patient satisfaction. Between-group difference in post-training improvement in 6MWD (mean: 17.14 m; 95% CI = 0.87 to 33.43 m) but not in Tlim (mean: 141.85seconds; 95% CI = -18.72 to 302.42seconds) was significantly higher in HFOT. The minimal clinically important difference of Tlim was reached by 47% of patients in the V-mask group and 56% of patients in the HFOT group, whereas the minimal clinically important difference of 6MWD was reached by 51% of patients in the V-mask group and 69% of patients in the HFOT group, respectively. In patients with hypoxemic COPD, exercise training is effective in improving exercise capacity. The addition of HFOT during exercise training is not more effective than oxygen through V-mask in improving endurance time, the primary outcome, whereas it is more effective in improving walking distance.

Assessment of cognitive function and hand dexterity in patients with chronic obstructive pulmonary disease: A cross-sectional study

Introduction: Chronic obstructive pulmonary disease (COPD) is a major public health problem worldwide and associated with multiple systemic involvements. Long-term hypoxia leads to impaired cognitive function and hand dexterity. With the background of few previous researches, we have aimed to assess cognitive function and hand dexterity in the patients with COPD as well as correlation between them and with oxygen saturation (SpO2). Materials and Methods: Data were collected and compared between 52 stable mild-to-moderate hypoxemic COPD patients defined by the Global Initiative for Obstructive Lung Disease Guidelines and 48 age- and sex-matched healthy volunteers attending the outpatient department of a government hospital Kolkata, using a validated questionnaire Mini-Mental State Examination (MMSE) tool for the assessment of cognitive function and the Nine-Hole Peg Test for assessment of hand dexterity. Results: The median (interquartile range [IQR]) value of Hand Dexterity Test for the dominant hand for the test group was 22 (20–24) s, and for the control group, 19 (18–20) s (P

Physical Activity in Patients with Chronic Obstructive Pulmonary Disease on Long-Term Oxygen Therapy: A Cross-Sectional Study.

Background and aimThere are few studies evaluating physical activity (PA) in patients with chronic obstructive pulmonary disease (COPD) on long-term oxygen therapy (LTOT).AimTo assess PA in hypoxemic COPD patients on LTOT.MethodsIn this cross-sectional study, we compared lung function, arterial blood gases, respiratory and peripheral muscle strength, 6-min walking distance (6MWD), daily energy expenditure and steps, and health-related quality of life (HRQL) in COPD patients on LTOT (LTOT group) versus two groups of control patients not needing LTOT: with (HYPOX) and without (COPD) exercise-induced desaturations.ResultsGroups did not differ as regards demographics, anthropometrics, peripheral or respiratory muscle strength. Compared to the other groups, LTOT patients had more severe airway obstruction and lung hyperinflation, greater number and severity of comorbidities, shorter 6MWD, as well as lower mean SpO2 during 6MWD and worse quality of life. LTOT patients had a lower daily energy expenditure, shorter time spent > 3.0 METs and longer sedentary time compared to the COPD group, and less daily steps compared to the other groups. No significant difference in any parameter of PA was found between COPD and HYPOX. In LTOT patients, daily steps showed a strong correlation with 6MWD, and a moderate correlation with airway obstruction, level of oxygenation, comorbidities and quality of life but not with peripheral and respiratory muscle strength. In COPD and HYPOX patients, daily steps were strongly correlated with 6MWD and level of oxygenation as assessed by PaO2/FiO2. There was no significant correlation between mean SpO2 and 6MWD in any group.ConclusionCOPD patients on LTOT perform less physical activity than patients not needing LTOT, both with and without exercise-induced desaturations. Patients with exercise-induced desaturations do not perform less physical activity than those without.

Comparison of supplemental oxygen delivery by continuous versus demand based flow systems in hypoxemic COPD patients - A randomized, single-blinded cross-over study.

Supplemental oxygen is a recommended therapy option in stable hypoxemic COPD patients. Often, supplemental oxygen is provided by continuous flow (CF). However, demand oxygen delivery systems (DODS) that provide an oxygen bolus only during inspiration have gained increasing use as they prolong oxygen cylinder life (beside battery life). However, there is a lack of evidence if different DODS and CF devices are equivalent. Seventy hypoxemic COPD patients (FEV1 32 ± 9% predicted, PaO2 56±7 mmHg) on long-term oxygen therapy were included in this prospective single-blinded, randomized cross-over trial. Following an initial incremental shuttle walk test, patients performed 3 endurance shuttle walk tests (ESWT) at 85% of their maximum walking speed in random order with: (A) CF (ESWT-CF), (B) a DODS based on liquid oxygen (ESWT-DL) and (C) an DODS oxygen concentrator (ESWT-DC). The primary outcome was oxygen saturation (SpO2) at ESWT isotime. Secondary outcomes were total ESWT duration, heart rate (HR) and breathing frequency (BF) at isotime and dyspnea at end-exercise. SpO2 at ESWT isotime was not clinically different between devices: 90 ± 4% (CF), 89 ± 5% (DL) and 90 ± 5% (DC). However, 20% of the patients showed a ≥4% lower oxygen desaturation while using a DODS device. Secondary outcomes were similar under the three conditions. Oxygen supplementation via DODS (based on liquid oxygen or as a concentrator) yielded comparable physiological effects during standardized walking in stable hypoxemic COPD patients like CF. However, 20% of patients showed a clinically relevant lower oxygen saturation while using a DODS device. Therefore, we suggest individual testing of oxygen saturation of DODS suitability.

Oxygen therapy improves cerebral oxygen delivery and neurovascular function in hypoxaemic chronic obstructive pulmonary disease patients.

What is the central question of this study? How does oxygen therapy influence cerebral blood flow, cerebral oxygen delivery and neurovascular function in chronic obstructive pulmonary disease patients? What is the main finding and its importance? Oxygen therapy improves cerebral oxygen delivery and neurovascular function in chronic obstructive pulmonary disease patients. This improvement in cerebral oxygen delivery and neurovascular function might provide a physiological link between oxygen therapy and a reduced risk of cerebrovascular disease (e.g. stroke, mild cognitive impairment and dementia) in chronic obstructive pulmonary disease. We investigated the role of hypoxaemia in cerebral blood flow (CBF), oxygen delivery (CDO2 ) and neurovascular coupling (coupling of CBF to neural activity; NVC) in hypoxaemic chronic obstructive pulmonary disease (COPD) patients (n=14). Resting CBF (duplex ultrasound), peripheral oxyhaemoglobin saturation (SpO2; pulse-oximetry) and NVC (transcranial Doppler) were assessed before and after a 20min wash-in of supplemental oxygen (∼3lmin-1 ). The peripheral oxyhaemoglobin saturation increased from 91.0±3.3 to 97.4±3.0% (P<0.01), whereas CBF was unaltered (593.0±162.8 versus 590.1±138.5mlmin-1 ; P=0.91) with supplemental O2 . In contrast, both CDO2 (98.1±25.7versus 108.7±28.4mldl-1 ; P=0.02) and NVC were improved. Specifically, the posterior cerebral artery cerebrovascular conductance was increased to a greater extent after O2 normalization (+40%, from 20.4±9.9 to 28.0±10.4% increase in conductance; P=0.04), whereas the posterior cerebral artery cerebrovascular resistance decreased to a greater extent during O2 normalization (+22%, from -16.7±7.3 to -21.4±6.6% decrease in resistance; P=0.04). The cerebral vasculature of COPD patients appears insensitive to oxygen, because CBF was unaltered in response to O2 supplementation leading to improved CDO2 . In patients, the improvements in CDO2 and neurovascular function with supplemental O2 may underlie the cognitive benefits associated with O2 therapy.

Adherence to long-term oxygen therapy in patients with chronic obstructive pulmonary disease.

Long-term oxygen therapy (LTOT) has beneficial effects on survival in patients with chronic obstructive pulmonary disease (COPD) and severe hypoxemia at rest. Two landmark trials suggested that these benefits depend on the time of exposure to oxygen. Patients are usually prescribed LTOT for at least 15–18 hours/day. The primary objective of this study was to determine the average daily exposure to supplemental oxygen in patients with severely hypoxemic COPD who were newly prescribed LTOT and the proportion of patients who were adherent to their prescription. The secondary objective was to identify predictors of compliance to LTOT. We performed a retrospective observational study of patients newly registered in a regional home oxygen program in Quebec, Canada, between July 1, 2013, and December 31, 2014. Daily exposure to oxygen was objectively measured from the concentrator’s counter clock. From 196 patients registered in the program during the study period, 115 contributed to the analysis. Most patients (n = 84; 73%) were prescribed oxygen for ≥18 hours/day. Overall, the 115 patients were exposed to home oxygen for 17.8 hours/day; 60% of the patients were compliant according to our definition. Increasing age and ambulatory oxygen utilization predicted adherence to oxygen therapy. Adherence to home oxygen therapy is suboptimal. Behavioral and psychological interventions to improve compliance to LTOT should be investigated.

Low-dose oxygen therapy in COPD patients: are there any radiation-like risks?

Low-dose oxygen (LDO) supplementation is used by millions of COPD patients worldwide. The therapeutic benefits of LDO supplementation are well known. There are also several concerns regarding the potential for cellular harm from LDO in COPD patients. This review summarizes the current arguments and evidence pertaining to this important topic. LDO therapy has been used in COPD patients for more than 50 years. Over the years, data from randomized controlled trials has confirmed that LDO provides survival benefit in COPD patients with severe hypoxemia. Recent data, however, show that LDO does not provide any morality benefit for patients with a less severe degree of hypoxemia. There are several theoretical concerns regarding use of LDO in COPD patients, including radiation-like cellular risks because of oxygen toxicity. However, none of these have been validated in human clinical trials and remain somewhat peripheral to the clinician deciding whether or not to initiate LDO in a hypoxemic COPD patient. There is high-quality evidence that LDO is both well tolerated and highly efficacious for patients with COPD. There are several theoretical concerns regarding damage from oxygen free radicals from LDO in COPD patients. However, none of these have been validated or confirmed in human clinical trial data. Thus, the benefits of LDO clearly outweigh the risks from any theoretical concerns about oxygen toxicity.

Effectiveness of pulmonary rehabilitation in COPD patients receiving long‐term oxygen therapy

It has been demonstrated that long-term oxygen therapy increased exercise capacity, improved the quality of life, reduced hospitalization and increased life expectancy in chronic hypoxemic COPD patients. The present study aims to evaluate the effectiveness of pulmonary rehabilitation (PR) in COPD patients receiving long-term oxygen therapy (LTOT) compared to COPD patients not receiving LTOT. Chronic hypoxemic COPD patients using LTOT (LTOT group) and COPD patients not receiving LTOT (non-LTOT group) who participated in this study underwent a comprehensive 8-week outpatient PR program. Twenty-seven out of 61 severe/very severe cases with COPD received LTOT at home, and 34 did not. After PR, 6-minute walking distance (6mWD) increased significantly and perceived dyspnea decreased significantly in both groups (P < .001, both). This change was significantly higher in the LTOT-receiving group compared to the non-LTOT Group (P = .046, P = .012). In both groups, all items in the disease-related quality of life questionnaire (QoL) were improved, and the scores in the health-related QoL questionnaire exhibited an improvement (P < .05, for all). Anxiety and depression scores were significantly lowered in both groups (P < .05, both). Those COPD patients receiving the LTOT benefited from the PR as much as those COPD patients not receiving LTOT. The former group had a higher increase in 6mWD and a higher reduction in dyspnea symptoms. Further studies are required to understand to what extent the severe chronic hypoxemic COPD patients could benefit from the PR.

Long-Term Oxygen Therapy 24 vs 15 h/day and Mortality in Chronic Obstructive Pulmonary Disease.

Long-term oxygen therapy (LTOT) ≥ 15 h/day improves survival in hypoxemic chronic obstructive pulmonary disease (COPD). LTOT 24 h/day is often recommended but may pose an unnecessary burden with no clear survival benefit compared with LTOT 15 h/day. The aim was to test the hypothesis that LTOT 24 h/day decreases all-cause, respiratory, and cardiovascular mortality compared to LTOT 15 h/day in hypoxemic COPD. This was a prospective, observational, population-based study of COPD patients starting LTOT between October 1, 2005 and June 30, 2009 in Sweden. Overall and cause-specific mortality was analyzed using Cox and Fine-Gray regression, controlling for age, sex, prescribed oxygen dose, PaO2 (air), PaCO2 (air), Forced Expiratory Volume in one second (FEV1), WHO performance status, body mass index, comorbidity, and oral glucocorticoids. A total of 2,249 included patients were included with a median follow-up of 1.1 years (interquartile range, 0.6–2.1). 1,129 (50%) patients died and no patient was lost to follow-up. Higher LTOT duration analyzed as a continuous variable was not associated with any change in mortality rate (hazard ratio [HR] 1.00; (95% confidence interval [CI], 0.98 to 1.02) per 1 h/day increase above 15 h/day. LTOT exactly 24 h/day was prescribed in 539 (24%) patients and LTOT 15–16 h/day in 1,231 (55%) patients. Mortality was similar between the groups for all-cause, respiratory and cardiovascular mortality. In hypoxemic COPD, LTOT 24 h/day was not associated with a survival benefit compared with treatment 15–16 h/day. A design for a registry-based randomized trial (R-RCT) is proposed.

Prevalence of overlap syndrome in chronic obstructive pulmonary disease patients without sleep apnea symptoms.

The co-existence of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) is a common phenomenon referred to as overlap syndrome (OS). In this study, we evaluated the prevalence of OS in mild hypoxemic COPD patients without OSA symptoms and compared characteristics of OS and COPD patients. Forty-five COPD patients (mean FEV1 1671.3 ± 532.0 mL) with mild hypoxemia presenting no sleep apnea symptoms (96% men, mean age 67.7 ± 8.5 years) were involved in this study. Clinical characteristics were recorded, biochemical analysis and polygraphy were performed. Twenty-six patients with a RDI of ≥15 events/h were defined as OS (58%). When OS (n = 26) and COPD without OSA (n = 19) groups were compared, BMI (29.6 ± 6.6 vs 25.6 ± 4.9 kg/m2 ; P = 0.03), TNF-α level (24.8 ± 8.1 vs 3.6 ± 0.8 ng/mL; P = 0.03) and sleep time with SpO2 < 90% (23.9 ± 29.4 vs 9.7 ± 21.9%; P = 0.02) were significantly increased in OS. Univariate analysis showed a correlation between RDI and BMI (P < 0.01), Epworth score (P = 0.050), COPD exacerbation frequency (P = 0.046) and TNF-α (P = 0.048). However, multivariate linear regression analysis revealed a significant correlation only between RDI and BMI (P < 0.01). BMI as a predictor of OSA was examined through ROC curve analysis and the area under curve was 0.691 (P = 0.03). To identify OS patients, BMI > 27.2 kg/m2 had a sensitivity of 73% and specificity of 68%. This findings support that high prevalence (58%) of OS in COPD patients without OSA symptoms is related to BMI. Therefore, sleep study should be considered in especially overweight or obese COPD patients, even in those without sleep apnea symptoms.

Link between non hypoxemic chronic obstructive pulmonary disease and executive functioning in oldest old

COPD (chronic obstructive pulmonary disease) may result in cognitive disorders (mainly executive) even without hypoxemia. The aim of this descriptive study was to highlight a deficit in task-switching in non-hypoxemic patient with COPD and mild cognitive impairment (MCI) or Alzheimer disease (AD). The main judgment criterion was patients' performances on the TMTA and B. COPD patients were recruited via the database (CogDisCo) of the geriatric medicine department at Pitié Salpêtrière hospital in Paris. 7 patients had Alzheimer's disease (AD), and 11 mild cognitive impairment (MCI): they were matched for age, sex, MMSE, education level with controls subjects without COPD. There was no significant difference between the two groups. However, patients with COPD and MCI required, on average, an extra 13 seconds compared with patient without COPD for the TMTA and 18 seconds for the TMTB. Patients with COPD and AD needed, on average, an extra 63 seconds for TMTA and 97 seconds for TMTB. The number of errors for the TMTB was the same in the both groups. This preliminary study does not show statistically significant results but the time for achieving TMT was longer in the population with COPD whether AD or MCI. These results encourage us to continue with prospective studies on larger samples.

Cognitive dysfunction in severe chronic obstructive pulmonary disease (COPD) with or without Long-Term Oxygen Therapy (LTOT).

BackgroundChronic Obstructive Pulmonary Disease (COPD) is a progressive respiratory condition which can lead to comorbidities of variable severity, cognitive dysfunction included. The role of supplemental oxygen in preventing COPD-induced cognitive deterioration is still debated, but only episodically investigated. The aim of this study was to compare the cognitive pattern of hypoxemic COPD subjects treated with long-term oxygen (LTOT) to that of patients of comparable severity assuming oxygen on irregular basis, and to normal reference values.MethodsLung function, arterial blood gases, health status, and cognitive function measured by means of four psychometric tests focusing different domains of cognition (such as: MMSE, Clock test; TMT-A; TMT-B) were assessed in 146 well matched hypoxemic COPD patients (males n = 96, 66%; mean age = 70.5 ± 12.9). Seventy-three patients were assuming long-term oxygen (LTOT), while the remaining seventy-three were only using oxygen as needed (AN). Regarding statistics, t test and ANOVA (Duncan test) were used to analyze data, assuming a p < 0.05 as the lowest limit of significance.ResultsEven though all COPD patients showed a poorer psychometric profile vs corresponding normal reference values, LTOT patients showed a lower prevalence of severe deterioration in cognition. Also the extent of impairment was significantly lower in these patients when assessed by TMT-A and TMT-B (p < 0.012 and 0.001, respectively), but not when measured by MMSE and Clock test (both p = ns). Several domains of cognition are variably affected by persistent hypoxemia in COPD patients. A panel of psychometric tools is needed for identifying the pattern of cognitive dysfunctions in these patients. Memory and attention (functions assessed by MMSE and Clock test) are only mildly-moderately affected, while visual processing, reproduction of numeric sequences, cognition flexibility, and shifting capacity (functions assessed by TMT-A and TMT-B) are much more deteriorated (p < 0.012 and p < 0.001, respectively).ConclusionsOnly LTOT allows to preserve significantly (p < 0.022) cognitive functions from the COPD-induced deterioration. This assumption is of strategic value for COPD patients who are prescribed long-term oxygen because they frequently are not aware of the cognitive risks related to their condition.

Cognitive dysfunction in severe chronic obstructive pulmonary disease (COPD) with or without Long-Term Oxygen Therapy (LTOT)

Background: Chronic Obstructive Pulmonary Disease (COPD) is a progressive respiratory condition which can lead to comorbidities of variable severity, cognitive dysfunction included. The role of supplemental oxygen in preventing COPD-induced cognitive deterioration is still debated, but only episodically investigated. The aim of this study was to compare the cognitive pattern of hypoxemic COPD subjects treated with long-term oxygen (LTOT) to that of patients of comparable severity assuming oxygen on irregular basis, and to normal reference values.&#x0D; Methods: Lung function, arterial blood gases, health status, and cognitive function measured by means of four psychometric tests focusing different domains of cognition (such as: MMSE, Clock test; TMT-A; TMT-B) were assessed in 146 well matched hypoxemic COPD patients (males n = 96, 66%; mean age = 70.5 ± 12.9). Seventy-three patients were assuming long-term oxygen (LTOT), while the remaining seventy-three were only using oxygen as needed (AN). Regarding statistics, t test and ANOVA (Duncan test) were used to analyze data, assuming a p &lt; 0.05 as the lowest limit of significance.&#x0D; Results: Even though all COPD patients showed a poorer psychometric profile vs corresponding normal reference values, LTOT patients showed a lower prevalence of severe deterioration in cognition. Also the extent of impairment was significantly lower in these patients when assessed by TMT-A and TMT-B (p &lt; 0.012 and 0.001, respectively), but not when measured by MMSE and Clock test (both p = ns). Several domains of cognition are variably affected by persistent hypoxemia in COPD patients. A panel of psychometric tools is needed for identifying the pattern of cognitive dysfunctions in these patients. Memory and attention (functions assessed by MMSE and Clock test) are only mildly-moderately affected, while visual processing, reproduction of numeric sequences, cognition flexibility, and shifting capacity (functions assessed by TMT-A and TMT-B) are much more deteriorated (p &lt; 0.012 and p &lt; 0.001, respectively).&#x0D; Conclusions: Only LTOT allows to preserve significantly (p &lt; 0.022) cognitive functions from the COPD-induced deterioration. This assumption is of strategic value for COPD patients who are prescribed long-term oxygen because they frequently are not aware of the cognitive risks related to their condition.

Oxygen therapy use in older adults with chronic obstructive pulmonary disease.

RationaleOxygen therapy improves survival and function in severely hypoxemic chronic obstructive pulmonary disease (COPD) patients based on two landmark studies conducted over 40 years ago. We hypothesize that oxygen users in the current era may be very different. We examined trends and subject characteristics associated with oxygen therapy use from 2001–2010 in the United States.MethodsWe examined Medicare beneficiaries with COPD who received oxygen from 2001 to 2010. COPD subjects were identified by: 1) ≥2 outpatient visits >30 days apart within one year with an encounter diagnosis of COPD; or 2) an acute care hospitalization with COPD as the primary or secondary discharge diagnosis. Oxygen therapy and sustained oxygen therapy were defined as ≥1 and ≥11 claims for oxygen, respectively, in the durable medical equipment file in a calendar year. Primary outcome measures were factors associated with oxygen therapy and sustained oxygen therapy over the study period.ResultsOxygen therapy increased from 33.7% in 2001 to 40.5% in 2010 (p-value of trend <0.001). Sustained oxygen therapy use increased from 19.5% in 2001, peaked in 2008 to 26.9% and declined to 18.5% in 2010. The majority of subjects receiving oxygen therapy and sustained oxygen therapy were female. Besides gender, factors associated with any oxygen use or sustained oxygen therapy were non-Hispanic white race, low socioeconomic status and ≥2 comorbidities.ConclusionsAny oxygen use among fee-for service Medicare beneficiaries with COPD is high. Current users of oxygen are older females with multiple comorbidities. Decline in sustained oxygen therapy use after 2008 may be related to reimbursement policy change.

Functional capacity, physical activity, and quality of life in hypoxemic patients with chronic obstructive pulmonary disease.

BackgroundThe risk of hypoxemia increases with the progression of chronic obstructive pulmonary disease (COPD) and the deterioration of pulmonary function. The aim of this study was to compare functional capacity, physical activity, and quality of life in hypoxemic and non-hypoxemic patients with COPD.MethodsThirty-nine COPD patients (mean age: 62.0±7.03 years) were included in this study. Arterial blood gas tensions were measured, and patients were divided into two groups according to oxygen partial pressure (PaO2), the hypoxemic COPD (PaO2 <60 mmHg) (n=18), and the control (PaO2 ≥60 mmHg) (n=21) groups. Functional exercise capacity was evaluated using the 6-minute walk test (6MWT). Oxygen saturation, dyspnea, and fatigue perception were measured before and after the 6MWT. Physical activity was assessed using the International Physical Activity Questionnaire (IPAQ) and an accelerometer. Quality of life was assessed using the St George’s Respiratory Questionnaire (SGRQ).ResultsThe number of emergency visits and hospitalizations were higher in hypoxemic patients (P<0.05). Lung function parameters, 6MWT distance, exercise oxygen saturation, IPAQ total score, and energy expenditure during daily life were significantly lower, but percentage of maximum heart rate reached during the 6MWT was significantly higher, in hypoxemic COPD patients than in controls (P<0.05).ConclusionHypoxemia has a profound effect on functional capacity and physical activity in patients with COPD.

Benefits of an Oxygen Reservoir Cannula versus a Conventional Nasal Cannula during Exercise in Hypoxemic COPD Patients: A Crossover Trial

Background: The Oxymizer® is a special nasal cannula that provides a higher luminal diameter in combination with an incorporated oxygen (O₂) reservoir. It is assumed that a higher O₂ concentration can be delivered breath by breath in order to increase oxygenation. Objective: We aimed to investigate the effects of the Oxymizer on endurance time in comparison to a conventional nasal cannula (CNC). Methods: Forty-three patients with severe chronic obstructive pulmonary disease (COPD, age 60 ± 9 years, FEV₁ 37 ± 16% pred.) and indications for LTOT were recruited during pulmonary rehabilitation for this cross-over study. After an initial maximal incremental cycle test, all patients performed 4 cycling endurance time tests at 70% of their peak work rate (twice with the Oxymizer and twice with a CNC, in reverse order). Results: The endurance time was significantly higher when patients cycled while using the Oxymizer in comparison to while using the CNC [858 ± 754 vs. 766 ± 652 s; between-group difference 92 s (95% confidence interval 32-152), p < 0.001]. In addition to a longer cycling duration, O₂ saturation at isotime was significantly higher with the Oxymizer (93.5 ± 5.4 vs. 90.4 ± 5.3%; p = 0.027). Furthermore, there was a positive correlation (r = 0.427, p = 0.002) between the O₂ flow rate and improvements in the constant work rate test, showing greater improvements in favor of the Oxymizer in patients with a higher demand for O₂ (≥4 liters/min). Conclusion: We show that O₂ delivery via the Oxymizer is superior to a CNC with regard to endurance capacity and oxygenation during exercise in patients with severe COPD. It seems that patients with a higher demand for O₂ (≥4 liters/min), in particular, may benefit more from the use of the Oxymizer.

Chronic Domiciliary Oxygen Therapy–Year SEPAR

Oxygen was the “rst treatment shown to increase survival in patients with chronic obstructive pulmonary disease (COPD). Current recommendations for the prescription of continuous domiciliary oxygen therapy (CDO) are based on the results of 2 clinical trials published over 30 years ago: the Nocturnal Oxygen Therapy Trial (NOTT) and the Medical Research Council (MRC) study. 1,2 CDO is indicated in patients with COPD and resting PaO2 �55 mmHg or resting PaO2 between 56 and 59 mmHg with evidence of chronic pulmonary hypertension or polycythemia. Based on the hypothesis that the bene“cial effect of oxygen is a result of the correction of hypoxemia, irrespective of the cause, this indication has been extended by analogy to chronic respiratory failure caused by other respiratory (idiopathic pulmonary “brosis, cystic “brosis, etc.) and non-respiratory diseases (heart failure). However, the effectiveness of continuous oxygen therapy on survival in these other disease entities has not been demonstrated, and studies justifying indication in these cases are required. 3 In contrast with the results of the MRC or NOTT clinical trials, supplementary oxygen has not been shown to improve survival in patients with COPD and moderate hypoxemia. 4 However, these studies have been criticized for reporting a small number of patients, an inappropriately short study period and inadequate average daily administration of oxygen–approximately 13.5 h, clearly insuf“cient for showing effects on mortality. It is known, for example, that patients with COPD and chronic respiratory failure receiving CDO have a rebound effect, with pulmonary vascular resistance increasing when oxygen is suspended for periods as short as 3 h a day. Moreover, it is clear that the mortality rate in COPD patients with comorbidities is higher. Nevertheless, none of the studies analyzing the effects of CDO evaluate the in”uence of comorbidities in general or of cardiovascular disease in particular. It is currently unclear if continuous oxygen therapy reduces metabolic and/or cardiovascular death in hypoxemic COPD patients. Current guidelines do not provide any indications for “pure” patients (with no associated comorbidities), and the therapeutic effects of CDO are analyzed in groups that are poorly representative of COPD patients. 5