Adrienne S. Scott

Fatigue in COPD: prevalence and effect on outcomes in pulmonary rehabilitation.

Patients with chronic obstructive pulmonary disease (COPD) complain of dyspnea and fatigue. We sought to estimate the prevalence of high fatigue in this population and to determine whether individuals with high fatigue had a different response to pulmonary rehabilitation. This observational study was embedded within a randomized trial. Participants underwent 3 months of pulmonary rehabilitation including education and exercise training. We divided 251 individuals into low and high fatigue groups using population normal scores of the SF-36 vitality domain. Baseline data included spirometry, 6-minute walk distance (6MWD), peak exercise capacity, constant workrate cycling endurance time, and questionnaires including the St. George’s and Chronic Respiratory questionnaires (SGRQ, CRQ). The response to pulmonary rehabilitation was evaluated using changes in these measures at 3 months and 1 year after entry. High fatigue was present in 97/251 (39%) of patients. High fatigue patients were younger, had more depressive symptoms, greater dyspnea and poorer SGRQ scores (p < 0.01). They also had lower 6MWD, endurance times, and peak volume of oxygen consumption (VO2; p < 0.05). Patients in both groups improved similarly in their dyspnea, the 6MWD and endurance time. High-fatigue patients had greater improvements in both the CRQ fatigue (by 0.74 more points) and the SGRQ scores (by 6.0 points; p < 0.01), with clinically significant gains maintained at 1 year. This study suggests that high levels of fatigue is a common feature in patients with COPD. They have a lower exercise capacity and a lower health status. However, they benefit from pulmonary rehabilitation.

Success in pulmonary rehabilitation in patients with chronic obstructive pulmonary disease

BACKGROUND Pulmonary rehabilitation (PR) is beneficial for some, but not all, patients with chronic lung disease. OBJECTIVES To determine the success rate of a comprehensive PR program for patients with chronic obstructive pulmonary disease (COPD) and to characterize the differences between responders and nonresponders. METHODS A chart review was performed on patients with a clinical diagnosis of COPD who were referred for PR. Success was defined according to clinically important changes in St Georges Respiratory Questionnaire scores and⁄or 6 min walk test distance. RESULTS The majority of subjects were men (58%) with a mean (± SD) age of 69±10 years (n=177). Sixty-two per cent of participants had a successful outcome with PR, with proportionally more responders noting subjective improvement than objective improvement on a 6 min walk test (73% versus 51%). Subjects with poor baseline St Georges Respiratory Questionnaire scores tended to improve the most (P=0.011 [ANOVA]). Successful participants had a greater forced expired volume in 1 s (1.1 L versus 0.9 L; P<0.05) and a lower BODE index (body mass index, airflow obstruction, dyspnea, and exercise capacity index) at baseline (9.6 versus 10.3; P<0.05). Success of PR was not correlated with age, sex, chronic hypoxemic respiratory failure or other chronic conditions. Successful participants were more likely to be compliant and to experience fewer adverse events (P≤0.001). CONCLUSIONS Our study reinforced the belief that the majority of participants with COPD benefit from PR. Few baseline characteristics were predictive of success. Subjectively measured improvement occurred more frequently than objectively measured improvement and was greatest in those with the poorest baseline values.

Oxygen desaturation during a 6 min walk test is a sign of nocturnal hypoxemia.

UNLABELLED BACKGROUND⁄ OBJECTIVES Patients with chronic obstructive pulmonary disease (COPD) may experience sleep disordered breathing with nocturnal desaturation. An exploratory study was performed to determine whether any commonly measured clinical parameters were useful in predicting nocturnal desaturation in patients with COPD. A validation study was subsequently performed to confirm the utility of the parameter identified in the exploratory study as most useful in this regard. METHODS A total of 103 (exploratory cohort) and 200 (validation cohort) consecutive patients with COPD admitted for pulmonary rehabilitation were evaluated. Standard outcome measures including nocturnal oximetry and the 6 min walk test (6MWT) on room air with continuous pulse oximetry were assessed. Patients with sleep apnea or those undergoing long-term oxygen therapy were excluded. RESULTS In the exploratory study, the mean (± SD) patient age was 70 ± 9.9 years, with forced expiratory volume in 1 s of 0.76 ± 0.34 L, which was 36 ± 16% of predicted. Body mass index, arterial oxygen tension, oxygen saturation by pulse oximetry at rest and during the 6MWT all demonstrated significant correlations with percentage of time spent with a saturation <90%. When the lowest pulse oximetry during the 6MWT was ≤88%, 10 of 21 patients demonstrated a saturation <90% for at least 30% of sleep time. This measure yielded a positive likelihood ratio of 3.77 (95% CI 1.87 to 7.62) compared with those who did not reach this threshold value. The validation study confirmed similar detection characteristics. CONCLUSIONS Results from the present study suggest that monitoring oxygen saturation changes during a 6MWT is useful in helping to identify COPD patients who may experience significant nocturnal desaturation.

Patient Knowledge in Chronic Obstructive Pulmonary Disease: Back to Basics

Patient education is integral to the care of patients with chronic obstructive pulmonary disease (COPD), and a cornerstone of self-management in chronic illness. We aimed to assess information needs and knowledge of patients with COPD. The Lung Information Needs Questionnaire (LINQ) and The Mount Sinai Hospital Questionnaire (MSHQ) were used. The LINQ identifies what COPD information the patient has, or is lacking. Higher scores in the LINQ define a greater information need. The MSHQ assesses a patients’ COPD knowledge. Higher scores in the MSHQ questionnaire indicate greater knowledge. Subjects, in (n = 38) and outpatients (n = 43) were aged (mean ± SD) 69 ± 9 years, 53% were women, and 36% had not completed high school. COPD was diagnosed 9 ± 7 years previously. Forty percent had recalled receiving specific COPD education. Mean forced expiratory volume in 1 second (FEV1) was 1.1 ± 0.6 Liters. Patients on average had a 29 ± 14% need for information as assessed by the LINQ. Patients indicated a 52 ± 34% need for information on diet and 43 ± 25% for self-management. The mean total score for the MSHQ was 71 ± 13%. The score on treatment was 76 ± 20% and 60 ± 14% on pathophysiology. There was a positive relationship between having prior COPD education, finishing high school and total MSHQ score (p< 0.05) and a positive correlation of prior COPD education and reduced LINQ total score (p < 0.01). Patients with COPD have received information and demonstrate some knowledge about their disease. However, there remains a need for more education on diet and self-management.

Unilateral hemidiaphragm weakness is associated with positional hypoxemia in REM sleep.

BACKGROUND Patients with unilateral diaphragmatic paralysis (UDP) have been reported to have varied respiratory symptoms and often reduced lung function. We sought to describe the polysomnographic respiratory characteristics in patients with UDP without obstructive sleep apnea. METHODS We prospectively collected 5 cases with clinical investigation regarding symptoms, lung function, and nocturnal polysomnography. The respiratory sleep characteristics were analyzed with standardized scoring of respiratory events in 30-sec epochs and comparison according to sleep-wake stages and body position with respect to oximetry. The cases were compared to 5 controls matched for age, gender, and body mass index. RESULTS Three of 5 patients had significant awake lung restriction with a mean (range) forced vital capacity of 1.89 (1.48-2.24) liters, 72% (45% to 102%) predicted. All had REM sleep with few apneas and episodes of prolonged hypopneas characterized by important desaturation noted on oximetry. These desaturations were greatest during REM sleep when the patients slept supine with a mean (SD) saturation of 90.8% (4.5%) and minimum of 64% or on the side unaffected by UDP with a mean saturation of 87.8% (5.3%) and minimum of 67% (p < 0.0001 compared to same positions awake). Other sleep stages had few, if any significant desaturations and these events rarely occurred when the patient slept in the supine position. Saturation was lower in all sleep-wake stages and sleep positions compared to controls (p < 0.0001). CONCLUSION Patients with UDP demonstrate position-dependent hypopneas in REM sleep with frequent desaturations.