Jean K. Berry

Subjective fatigue, influencing variables, and consequences in chronic obstructive pulmonary disease

Background: Fatigue is a common symptom of chronic obstructive pulmonary disease (COPD), but little is known about the specific nature of COPD-related fatigue and its impact on daily life. Objectives: To (a) describe characteristics of fatigue in people with COPD and (b) test a theoretically and empirically supported model of the relationships among subjective fatigue, dyspnea, functional performance, anxious and depressed moods, and sleep quality in people with COPD. Methods: A cross-sectional descriptive study was conducted with 130 people with moderate to severe COPD. Measures included the following: a Numerical Rating Scale (NRS) for frequency, intensity, and distress of fatigue and dyspnea; Fatigue Assessment Instrument (FAI); Chronic Respiratory Disease Questionnaire (CRQ); Profile of Mood States (POMS); Pittsburgh Sleep Quality Index (PSQI); Functional Performance Inventory (FPI); and spirometry. Path analysis was used to examine the relationships among variables. Results: Participants reported moderate amounts of fatigue, which was described as situation-specific, had considerable consequences, and was responsive to rest and sleep. Dyspnea was slightly greater than fatigue, as measured by the NRSs (p <.001), and there was a strong relationship between fatigue and dyspnea (r =.74, p < .001). Dyspnea, depressed mood, and sleep quality accounted for 42% of the variance in subjective fatigue. Fatigue, dyspnea, airflow obstruction, and anxious mood accounted for 36% of the variance in functional performance. Conclusions: Fatigue is an important problem that affects performance of daily activities in people with COPD. The relationships or interactions that exist among fatigue and other symptoms are complex.

High-intensity inspiratory muscle training in patients with chronic obstructive pulmonary disease and severely reduced function.

PURPOSE This study examined the effects of inspiratory muscle training (IMT) with high-intensity inspiratory pressure loads on respiratory muscle performance and exertional dyspnea. METHODS This was a randomized single-blind clinical trial. Twenty-seven patients with chronic obstructive pulmonary disease (18 men, 9 women) with severe to very severe airflow obstruction and severely limited functional performance were assigned randomly to an IMT group (n = 12) or an educational control group (n = 15). The IMT group trained with a threshold loaded device for 30 minutes a day for 16 weeks using interval training techniques. Training was initiated with inspiratory pressure loads equal to 30% of maximal inspiratory pressure (Plmax) and increased as tolerated to 60% of Plmax. Dependent variables were measured before and after 4 months of IMT: inspiratory muscle strength (Plmax), respiratory muscle endurance (discontinuous incremental threshold loading test [DC-ITL]), dyspnea (Chronic Respiratory Disease Questionnaire [CRQ]), and the Borg Category-Ratio Scale ratings of perceived breathing difficulty (RPBD) at equal loads during the DC-ITL. RESULTS In the IMT group, Plmax increased from 64 +/- 15 to 75 +/- 17 cm H2O (P < .05), performance on the DC-ITL test increased from a maximal load of 37 +/- 12 to 53 +/- 13 cm H2O (P < .05), RPBD decreased from 5.5 +/- 2.5 to 3.8 +/- 2.6 for equal loads on the DC-ITL (P < .05) and the CRQ Dyspnea Scale improved from 18.1 +/- 5.1 to 22.4 +/- 5.2 (P < .05). CONCLUSIONS Inspiratory muscle training at high-intensity loads significantly improved inspiratory muscle strength, respiratory muscle endurance, and respiratory symptoms during daily activities and respiratory exertion.

RESPIRATORY MUSCLE STRENGTH IN OLDER ADULTS

Gender-related effects and two measures of muscularity, handgrip strength and fat-free mass (FFM), were examined to determine their relationship to respiratory muscle strength. Subjects were 101 healthy older adults. In 75 subjects, the magnitude of learning effect was examined over four weekly sessions. Maximal inspiratory pressure (PImax) was lower with increasing age in women, and maximal expiratory pressure (PEmax) was lower with increasing age in both genders. The PEmax correlated with handgrip strength and FFM in men only. Performance of PImax plateaued by the third visit in both men and women. Performance of PEmax plateaued by the third measure in women and was unchanged across four measurements for men.

Reliability and validity of the functional performance inventory in patients with moderate to severe chronic obstructive pulmonary disease.

The Functional Performance inventory (FPI) is a new instrument designed to measure functional status in terms of activities that people perform on a daily basis. Psychometric characteristics were examined by a survey of 45 men and 27 women with chronic obstructive pulmonary disease (COPD). Internal consistency reliability was high and no ceiling and floor effects were observed for the Total FPI. Concurrent validity was demonstrated by correlations with the Total Sickness Impact Profile (r = -.59). Construct validity was supported by correlations with the Medical Outcomes Study Short Form-36, Physical Functioning (r = .69), the Physical Activity Scale for the Elderly (r = .62) and American Thoracic Society-Division of Lung Disease Breathlessness scale (r = - .62). The Total FPI is a reliable and valid measure of functional performance in persons with COPD.

Regional body composition: cross-calibration of DXA scanners-QDR4500W and Discovery Wi.

Differences exist in body composition assessed by dual‐energy X‐ray absorptiometers (DXAs) between devices produced by different manufacturers and different models from the same manufacturer. Cross‐calibration is needed to allow body composition results to be compared in multicenter trials or when scanners are replaced. The aim was to determine reproducibility and extent of agreement between two fan‐beam DXA scanners (QDR4500W, Discovery Wi) for body composition of regional sites. The sample was: 39 women 50.6 ± 9.6 years old with BMI 26.8 ± 5.5 kg/m2, body fat 33 ± 7%. Four whole body scans (two on each device) were performed over 3 weeks. Major variables were fat mass, nonosseous lean mass, and bone mineral content (BMC) for the truncal and appendicular regions. Extent of agreement was assessed using Bland and Altman plots. Both devices demonstrated good precision with mean test–retest differences close to zero for fat mass, nonosseous lean mass, and BMC of the truncal and appendicular regions. Evaluation of interdevice agreement revealed significant differences for truncal and appendicular BMC, nonosseous lean mass, and fat mass. The greatest interdevice difference was for truncal fat mass (0.69 ± 0.60 kg). Differences in truncal and appendicular fat mass increased in magnitude at higher mean values. Furthermore, differences in truncal and appendicular fat mass were strongly related to BMI (R = −0.61, R = −0.55, respectively). In conclusion, in vivo cross‐calibration is important to ensure comparability of regional body composition data between scanners, especially for truncal fat mass and for subjects with higher BMI.

Importance of cross-calibration when replacing DXA scanners: QDR4500W and Discovery Wi.

The aim of the study was to determine reproducibility and extent of agreement between 2 dual-energy X-ray absorptiometers (Hologic QDR4500W, Discovery Wi). The average age of the sample (n = 42) was 50.4 (SD = 9.9) years old and 27.1 (SD = 6.1) kg/m2 body mass index. Four scans were performed with each subject (2 on each device) over ∼3 weeks. Whole body, proximal femur, and spine scans were performed at each visit. Major variables were whole body bone mineral content (BMC), fat mass, and nonosseous lean mass, and bone mineral density (BMD) of total proximal femur, femoral neck, total spine. Bland and Altman plots assessed the extent of the agreement. Regression analysis was used to develop correction equations if indicated. Both devices demonstrated good precision for whole body composition and BMD of central sites (<1% different). Interdevice agreement was acceptable for BMD of central sites (<1% different), but there were systematic differences for whole body composition between the 2 devices. It was concluded that when replacing an existing scanner with a new model, in vivo cross-calibration is important to ensure comparability of scan data, especially for whole body composition.

Reversal of chronic obstructive pulmonary disease-associated weight loss : are there pharmacological treatment options?

Poor nutritional status is associated with an increased incidence of morbidity and mortality in patients with chronic obstructive pulmonary disease (COPD). While a number of factors have been shown to produce tissue catabolism, no single mechanism has been clearly identified as a primary cause for weight loss in patients with severe COPD. Without a clear understanding of the aetiology of weight loss, therapeutic strategies to reverse this process have historically been unsuccessful. A review of recent studies allows consideration of a model of mechanisms of weight loss. This model includes multiple pathways that may be activated singly or simultaneously to cause loss of weight, specifically lean body mass. These include energy imbalances, elevated levels of cytokines, tissue hypoxia and the effects of cocorticosteroid therapy.To date, interventional studies that have looked at newer pharmacotherapies such as growth hormone and anabolic steroids in patients with COPD who arelosing weight have not demonstrated reversal of weight loss or improvement in nutritional status. Currently, early identification of patients at risk for weight loss and aggressive nutritional supplementation coupled with an exercise programme has demonstrated the greatest benefit. However, with increasing understanding of the mechanisms that may be implicated, new targets for therapies are being identified.Of particular research interest are molecules such as leukotrienes, hormones, tumour necrosis factor-α and acute-phase proteins, which are noted to be elevated in some patients with COPD-associated weight loss. Currently, inhibitors to some of these inflammatory substances are used therapeutically in other chronic illnesses such as rheumatoid arthritis and cancer cachexia. Future research may investigate their usefulness in COPD and direct new therapies that target the processes contributing to weight loss in these patients.

Malnutrition in Chronic Obstructive Pulmonary Disease: Adding Insult to Injury

Weight loss in patients with chronic obstructive pulmonary disease has a negative effect on the clinical course of the patient. Causes of weight loss in this population are known to include the effects of an energy imbalance, increased cytokines, hypoxia, and glucocorticoid use. This article delineates mechanisms included in these processes and highlights specific deleterious aspects of each. In addition, the effects of the following therapies are discussed in light of recent research findings: nutrition support, anabolic steroids, recombinant human growth hormone, and polyunsaturated fatty acids. This review summarizes the current state of knowledge in this area.

Nutritional Assessment of the Critically III Patient

Nutritional assessment can be incorporated into the assessments performed daily by the critical care nurse for every patient. Identification of nutritional deficits will lead to timely interventions and will facilitate recovery and early discharge. The metabolic responses to starvation and stress are reviewed, and bedside techniques for nutritional assessment are outlined. General guidelines for nutritional support and parameters for monitoring the effectiveness of nutritional therapies are defined.

Chronic obstructive pulmonary disease.

Mrs. S, a 51-year-old woman, presents to the occupational health clinic for her annual employee physical. She complains of increasing breathlessness and a productive cough that is worse in the early morning. She states that these symptoms have become progressively worse for the past several years and attributes them to “getting older and gaining weight around the middle.” Her smoking history consists of one pack of cigarettes per day from ages 18 to 48; however, she has decreased that amount to approximately 1⁄2 pack per day since the no smoking policy was instituted in the workplace several years ago. She denies any history of asthma, has no other significant past health history, and takes no regular medications. End expiratory wheezes and expiratory phase prolongation are noted during chest examination. The occupational health nurse suspects that Mrs. S has chronic obstructive pulmonary disease (COPD) and orders office spirometry, performed before and after administering a short-acting bronchodilator. Results show obstruction without a bronchodilator response. Mrs. S is educated about COPD and the importance of smoking cessation. She is enrolled in the company smoking cessation group, started on a bronchodilator, and given a referral to a pulmonologist for full pulmonary function testing and further management. Mrs. S is weighed and her height is measured. Her body mass index is calculated as 30, placing her in the obese category. Her waist measurement is greater than 35, indicating central obesity and placing her at increased risk for diabetes and other obesity-related diseases. She is counseled regarding weight loss and referred to a weight-loss program, as the occupational health nurse has also identified weight as an aggravating factor for her breathing difficulty. This article reviews COPD and provides suggestions to help occupational health nurses recognize it and implement strategies to prevent its progression and exacerbation. Although COPD has traditionally been considered a disease of the elderly, it also afflicts the work force. A 1995 National Ambulatory Medicine survey showed that approximately 70% of individuals with COPD were younger than 65 (Sin, Stafinski, Chu, Bell, & Jacobs, 2002). Due to its progressive and debilitating nature, COPD can interfere with individuals’ ability to work, leading to reduced productivity and lost wages for employers and employees, respectively.