Work Capacity In Patients Research Articles

The role of fear-avoidance beliefs in patients with neck pain: relationships with current and future disability and work capacity

Objectives: To investigate the relationship between fear-avoidance beliefs and future disability and work capacity in patients with neck pain. Design: A prospective observational study. Setting: Physiotherapy outpatient departments. Patients: One hundred and twenty patients with neck pain intensity sufficient to affect their work capacity. Interventions: Patients participated in either six-week conventional physiotherapy or an exercise training programme to test whether the type of treatment received by the patients together with other outcome measures affected the predictive power of fear-avoidance beliefs. Main outcome measures: Patients underwent examination of the active neck range of movements and neck muscle strength and completed the Fear-Avoidance Beliefs Questionnaire, the Northwick Park Neck Pain Questionnaire, the Medical Outcomes 36-Item Short-Form Health Survey and the 11-point pain numerical rating scale. These were assessed at the beginning and at week 6 of the rehabilitation programme. Patients' work capacity was assessed at week 6 and three months after the six-week rehabilitation programme. Results: Spearman's correlation coefficients between fear-avoidance beliefs and initial and week 6 disability levels were 0.47 and 0.48, respectively. Regression analysis showed that the fear-avoidance beliefs significantly improved the goodness of fit of the model for predicting week 6 disability levels and return to complete work capacity at week 6 and three months after the rehabilitation programme, even after controlling for the physical impairments, the health status, the pain intensity and the type of treatment received. Conclusions: The fear-avoidance beliefs factor is an important biopsychosocial variable in predicting future disability level and return to complete work capacity in patients with neck pain.

325: Survival and functional status in patients 10 years after lung transplantation in Lund, Sweden

Purpose: The purpose of the study was to describe the true survival, lung function, and physical working capacity in patients ten years after lung transplantation at the Lund University Hospital. Methods and Materials: Thirty-nine patients were transplanted between January 1990 and December 1995 and included in the analysis. All patients received induction therapy with ATG. All were put on triple immunosuppression with CyA, AZA and steroids. The method was to compile the results from spirometry, 6-minute walk test and working capacity measured by bicycle ergometer from the ten year check-up. Results: 22 of the 39 have survived ten years or more after the lung transplantation. One-, fiveand ten-year survival were 87%, 72% and 59% respectively. Median vital capacity was 82 % (43-119) of predicted values and the forced expiratory volume in 1 second was 84 % (22-144) of predicted values. The median walking distance of the 6-minute walk test was 454 m (218-614 m) or 78 % (34-123) of predicted values. The median result of the bicycle working capacity was 52 % (33-112) of predicted values. Conclusions: The survival rate of the lung transplanted patients in Lund was good compared to other published data. The patients as a group had lung function values which were a bit lower than normal. Functional capacity measured as 6-minute walk was at the lower end of predicted while working capacity measured by bicycle ergometer was considerably reduced. Lung function was not function limiting in the majority of the patients but rather peripheral muscle function. 326

Cost of Finnish statutory inpatient rehabilitation and its impact on functional and work capacity of patients with early rheumatoid arthritis: experience from the FIN‐RACo trial

Objective: To explore the cost of the statutory inpatient rehabilitation system in Finland and its impact on the functional and work capacity of patients with early rheumatoid arthritis (RA).Methods: In the Finnish Rheumatoid Arthritis Combination‐Therapy trial (FIN‐RACo), 195 patients with recent‐onset RA, 162 of them available for the work force, were randomly assigned to two different drug treatment strategies for 2 years. Otherwise, the patients received routine multidisciplinary care and, if their functional or work capacity was endangered, were referred to inpatient rehabilitation. After a 5‐year follow‐up, data on rehabilitation, sick leave, and RA‐related disability pensions were obtained from official registers.Results: Of the 162 patients, 49 (30%) underwent inpatient rehabilitation at an average cost of EURO5400. The rehabilitated patients more often worked in white‐collar jobs and had more pain and a worse Health Assessment Questionnaire (HAQ) score (1.0 vs. 0.78; p = 0.01) at baseline. Their HAQ scores remained higher throughout follow‐up (p<0.001); no change appeared over inpatient periods [mean 0.01; 95% confidence interval (CI) −0.13 to 0.16]. No independent impact of rehabilitation on the HAQ score emerged in an adjusted generalized estimating equations (GEE) model (p = 0.55). Nor did any improvement in work capacity appear: average lost productivity (human capital approach) per patient‐year was EURO10 155 (95% CI 6994–14 196) before and EUR 12 839 (95% CI 8589–19 139) after the start of rehabilitation.Conclusion: For patients with recent‐onset RA, the Finnish statutory inpatient rehabilitation system had no positive impact on either functional or work capacity during the first few years, despite its considerable cost.

Working Capacity and Well-Being after Radical Cystectomy with Continent Cutaneous Diversion

ObjectivesThe primary aim was to compare the working capacity in patients with continent urinary diversion with a control group. Secondary aims were to assess the changes in electrolyte and acid-base homeostasis and the functional status during strenuous physical activity, and finally, the well-being in the two groups. MethodsEleven patients who had undergone radical cystectomy and continent cutaneous diversion using an ileocolonic segment participated. The control group consisted of 12 men, matched for age and activity level. Working capacity was assessed by ergospirometry on an exercise bicycle. Venous blood samples were taken before the test, when the expiratory exchange ratio (RER) was about 1.0 and immediately after completion of the test. SF-36 was used to evaluate the subject’s functional status and well-being. ResultsThe median working capacity in the patient group was 155 (85–190) W and 155 (125–215) W in the control group (n.s.) corresponding to 72 (43–97) % and 80 (59–97) % respectively of predicted values. Peak oxygen uptake was somewhat low in both groups when compared to P-O Åstrands norms. Blood tests revealed that patients developed a slight metabolic hyperchloremic acidosis, not seen in the control group. There were no differences between the groups as assessed with SF-36. ConclusionPatients with a continent urinary diversion have a working capacity equal to a control group despite a slight metabolic hyperchloremic acidosis. Quality of life was similar in the two groups and corresponded well with the norms for the general Swedish population aged 65 to 74.

Predictive factors for work capacity in patients with musculoskeletal disorders

To identify predictive factors for work capacity in patients with musculoskeletal disorders. A descriptive, evaluative, quantitative study. The study was based on 385 patients who participated in a rehabilitation programme. Patients were divided into 2 groups depending on their ability to work. The groups were compared with each other with regard to sociodemographic factors, diagnoses, disability pension and number of sick days. The patient's level of exercise habits, ability to undertake activities, physical capacity, pain and quality of life were compared further using logistic regression analysis. Predictive factors for work capacity, such as ability to undertake activities, quality of life and fitness on exercise, were identified as important independent factors. Other well-known factors, i.e. gender, age, education, pain and earlier sickness certification periods, were also identified. Factors that were not significantly different between the groups were employment status, profession, diagnosis and levels of exercise habits. Identifying predictors for ability to return to work is an essential task for deciding on suitable individual rehabilitation. This study identified new predictive factors, such as ability to undertake activities, quality of life and fitness on exercise.

Effect of Fuels on Exercise Capacity in Muscle Phosphoglycerate Mutase Deficiency

Muscle phosphoglycerate mutase deficiency (PGAMD) is a rare, recessively inherited metabolic myopathy that affects one of the last steps of glycolysis. Clinically, PGAMD resembles muscle phosphorylase deficiency (McArdle disease) and phosphofructokinase deficiency (PFKD). However, it is unknown whether PGAMD is associated with a second-wind phenomenon during exercise, as in McArdle disease, and whether patients with PGAMD, like patients with PFKD and McArdle disease, benefit from supplementation with fuels that bypass the metabolic block. To investigate whether fuels that bypass the metabolic block can improve exercise capacity or whether exercise capacity improves during sustained exercise. Single-blind, placebo-controlled investigation of the effects of glucose, lactate, and intralipid on work capacity in patients with PGAMD. National University Hospital, University of Copenhagen, and Neuromuscular Center, Institute for Exercise and Environmental Medicine. Patients Two unrelated men (21 and 26 years old) with PGAMD who since their teens had experienced muscle cramps, muscle pain, and episodes of myoglobinuria provoked by brief vigorous exercise, 4 patients with McArdle disease (mean +/- SD age, 32 +/- 5 years) with 0% residual phosphorylase activity in muscle, and 6 healthy, untrained male volunteers (mean +/- SD age, 23 +/- 1 years) were studied. Using constant and variable workload protocols on a cycle ergometer, it was investigated whether a spontaneous second wind occurs during exercise in patients with PGAMD, and using a constant workload protocol followed by an incremental load to exhaustion, it was tested whether infusion of lactate, glucose, or intralipid alters the exercise tolerance in PGAMD. Whether a second wind occurs during exercise and whether fuels that bypass the metabolic block can improve exercise and oxidative capacity. In contrast to patients with McArdle disease, with whom they share many clinical features, in patients with PGAMD, cycle exercise and oxidative capacity are virtually normal, a second wind does not occur, and lipid and lactate supplements do not improve exercise capacity. Although the clinical manifestations of PGAMD mimic McArdle disease with respect to the presence of exertional muscle cramps, rhabdomyolysis, and myoglobinuria, this study shows that cycle exercise responses are strikingly different.

Early suppression of disease activity is essential for maintenance of work capacity in patients with recent‐onset rheumatoid arthritis: Five‐year experience from the FIN‐RACo trial

To explore the impact of an early treatment response on maintenance of work capacity in patients with early, active rheumatoid arthritis (RA). In the Finnish Rheumatoid Arthritis Combination Therapy trial, 195 patients with recent-onset RA were randomized to receive either a combination of disease-modifying antirheumatic drugs (DMARDs) with prednisolone or a single DMARD with or without prednisolone for 2 years. Treatment responses were evaluated according to the American College of Rheumatology (ACR) criteria. After a 5-year followup, the cumulative number of days of sick leave and RA-related permanent work disability was calculated for each of the 162 patients who were available for the active work force at baseline. Of the 159 patients assessed at 6 months, 29 were in clinical remission, 66 achieved an ACR50 response but not remission, 29 achieved an ACR20 response but not an ACR50 response, and 35 failed to achieve an ACR20 response. In these 4 groups, the median numbers of work disability days per patient-year from 6 months through 60 months of followup were 0 (interquartile range [IQR] 0-3), 4 (IQR 0-131), 16 (IQR 0-170), and 352 (16-365), respectively (P < 0.001). Pairwise multiple comparisons showed a statistically significant difference between all groups except the ACR50 and ACR20 groups. At 12 months, 30 patients were in remission. None of the 44 patients in remission at 6 or 12 months became permanently work disabled over the 5-year followup, as compared with 15 patients in the ACR50 group (23%), 6 in the ACR20 group (21%), and 19 without an ACR20 response at 6 months (56%). Prompt induction of remission translates into maintenance of work capacity. At 6 months, an ACR50 response is no better than an ACR20 response with regard to future productivity, while failure to achieve an ACR20 response carries a high risk for work disability.

Effects of dynamic strength training on physical function, Valpar 9 work sample test, and working capacity in patients with recent-onset rheumatoid arthritis.

To study the impact of 24 months of strength training on the physical function of patients with early rheumatoid arthritis (RA). Seventy patients were assigned to either the strength training (experimental) group (n = 35) or the control group (n = 35). Patients in the experimental group performed strength training for 24 months, and control patients were instructed to perform range of motion exercises. Maximal strength of the knee extensors, trunk flexors, and extensors, as well as grip strength were recorded with dynamometers. Disease activity was assessed by the erythrocyte sedimentation rate and Ritchie's articular index, joint damage was determined by the Larsen x-ray index, and functional capacity was assessed using the Valpar 9 test and the Stanford Health Assessment Questionnaire (HAQ). The employment status of each patient was recorded. In the experimental group, strength training led to significant increases (19-59%) in maximal strength of the trained muscles. Such increases in the control group varied from 1% to 31%. There was a clear training effect on muscular strength in favor of the experimental group, but significant improvements in the HAQ indices as well as in the Valpar 9 test were seen also in control patients. Results of the Valpar 9 and the HAQ were statistically significantly better in patients who remained gainfully employed compared with patients who retired preterm during followup. However, compared with patients who remained in the work force, patients who retired were older, and their work was physically more demanding. As expected, strength training led to increased muscle strength, but this increase did not correlate with improved physical function as assessed by the Valpar 9 work sample test. The increased muscle performance did not prevent a substantial proportion of patients from retiring preterm. The 2 items from the Valpar 9 test that were applied were not sensitive enough to differentiate the patients according to their working status.

Myocardial collagen type I and impaired left ventricular function under exercise in hypertrophic cardiomyopathy.

Transaortic subvalvular myectomy (TSM) reduces left ventricular outflow tract gradient and improves symptoms and working capacity in patients with hypertrophic obstructive cardiomyopathy (HOCM). Nevertheless, TSM does not completely restore normal ventricular function, and some patients complain of symptoms despite optimal surgical results. Abnormal myocardial collagen structure in hypertrophic cardiomyopathy might be an indicator of impaired cardiac function. Nine patients with HOCM were investigated. Myocytic diameter, collagen volume fraction and light absorbance of immunohistochemically stained collagen subtype I and its product (Coll I(prod)) were measured quantitatively in myectomy specimens. Patients underwent symptom-limited bicycle exercise testing with equilibrium radionuclide angiocardiography to determine ejection fraction (EF). Right heart catheterization was performed simultaneously in order to measure pulmonary capillary wedge pressure (PCWP) as a parameter of global ventricular diastolic filling and cardiac index (CI) as a parameter of functional capacity. Postoperatively, CI increased from 3.1 +/- 0.4 to 5.7 +/- 1.3 l/min/m(2) under exercise. EF was normal at rest (64 +/- 9 %) but did not increase significantly under exercise (66 +/- 14 %). Coll I(prod) (13.62 +/- 7.35 Vv%(prod)) correlated inversely with EF under exercise (r = -0.64; p = 0.05). PCWP increased under exercise from 8 +/- 2 mmHg at rest to 22 +/- 9 mmHg (p = 0.01). Coll I(prod) correlated with PCWP under exercise (r = 0.90; p = 0.001). Increased collagen subtype I is a predictor of diastolic as well as systolic dysfunction under exercise in patients with HCM after successful TSM.

Studies of impact on physical fitness and working capacity of patients with advanced Schistosomiasis japonica in Susong County, Anhui Province

To assess the impact level on physical fitness and working capacity in patients with advanced Schistosomiasis japonica, a field study was carried out. According to the records of patients with advanced schistosomiasis in Susong County, Anhui Province, 48 advanced cases without other serious chronic diseases from endemic areas in two townships and 56 healthy individuals from non-endemic area, served as control group with matched ages between 40 and 70 years and matched sex were investigated with questionnaire, anthropometric measure and hemoglobin level. The impairment level of the liver was measured by ultrasonography and physical fitness was measured by the Step test in the case and control groups. All situations including lifestyle, working, socio-economic status and residing environment was similar in the case and control groups. Average height and weight was significantly lower in the case group than in the control group (height=156.29 and 159.41 cm; weight=50.72 and 53.92 kg; respectively, all P<0.05). Thirteen individuals (28.3%) in the case group had moderate reduction of working capacity or even unable to work, but only seven (12.7%) individuals in the control group had moderate reduction of working capacity and all in the control group were able to work ( P<0.01). In the past 1 year, the average working days lost was 4.11 days in the case group and 0.86 day in the control group ( P<0.01). Both groups differed significantly in symptoms of abdominal pain, diarrhea and weakness (all P<0.05). Twenty-one cases (43.8%) had grade II impairment of the liver and eight cases (16.7%) had grade III impairment of the liver in the case group, whereas seven individuals (12.7%) had grade II impairment of the liver in the control group ( P<0.01), as assessed by ultrasound. The hemoglobin levels and the power of gripping in the case group were significantly lower than those in the control group (Hb=111.06 and 122.27 g/l; grip=303.83 and 344.20 N, respectively, all P<0.01). Physical fitness scores showed the control group (score: 71.84) was significantly fitter than the case group (score: 61.09, P<0.01). Compared with the control group, the physical fitness of the case group reduced by 15%. The results showed that physical fitness and working capacity were reduced in advanced cases. Although most of the cases were treated and had reached a status of ‘clinical cure’, the impact on physical fitness and working capacity still existed.

Effects of Dobutamine on Critical Capillary Po2 and Lactic Acidosis Threshold in Patients With Cardiovascular Disease

Muscle capillary PO(2) has been found to reach a minimal value, ie, a critical capillary PO(2), in the midrange of work capacity in patients with cardiovascular disease. However, it is not known if the critical capillary PO(2) can be influenced by a change in blood flow response to exercise. This study was carried out to determine the effect of changing the blood flow response to exercise, using low-dose infusion of dobutamine, on muscle end-capillary PO(2) (as approximated by femoral vein PO(2)), lactate concentration, oxygen uptake (O(2)), and the relation among these variables. Eleven male patients with coronary artery disease performed an incremental exercise test on a cycle ergometer with and without continuous infusion of dobutamine, 6 microg/kg/min. Respiratory gas analysis was performed on a breath-by-breath basis; femoral vein blood was sampled every minute through a percutaneous catheter. Dobutamine increased resting O(2) and O(2) at the lactic acidosis threshold (LAT) but not peak O(2). The femoral vein PO(2) rapidly decreased toward a minimal value with increasing work rate (O(2)) irrespective of the infusion of dobutamine. After reaching its nadir (critical PO(2)), femoral vein lactate began to increase without further decrease in PO(2). Infusion of dobutamine significantly increased femoral vein resting PO(2) (27.4 +/- 4.9 mm Hg vs 32.5 +/- 3.8 mm Hg) and critical PO(2) (20.5 +/- 1.5 mm Hg vs 21.9 +/- 1.7 mm Hg), but not the PO(2) at peak O(2) (22.1 +/- 3.3 mm Hg vs 22.0 +/- 2.9 mm Hg). Infusion of dobutamine was found to raise the critical PO(2) and LAT but not peak O(2). These findings suggest that some of the acute increase in blood flow induced by dobutamine infusion benefits exercising muscle by increasing capillary PO(2), thereby delaying the onset of lactic acidosis.

Effect of growth hormone deficiency on physical work capacity in patients with non-insulin-dependent diabetes mellitus and excessive body weight

Effect of growth hormone deficiency on physical work capacity in patients with non-insulin-dependent diabetes mellitus and excessive body weight

Impairment Tutorial: Impairment From Coronary Artery Disease

Abstract Coronary artery disease is quite common, and physicians often are asked about the work capacity of patients with coronary disease; less commonly are physicians asked to rate the patient's permanent impairment. In such cases, Chapter 6, Cardiovascular System, of the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides) is used to rate impairment. The AMA Guides directs the physician who is rating impairment to place the individual in one of four classes of impairment. Class 1 impairment is rarely used because patients often have neither significant lesions nor a history of angina. The likelihood of disease progression may qualify these individuals as impaired even in the absence of symptoms. Patients with Class 2 impairment have no symptoms even with moderately heavy activity, and moderate dietary adjustment or medication is required to prevent symptoms. Class 3 impairment describes individuals who have symptoms of congestive heart failure or angina with moderately heavy activity. According to the AMA Guides criteria, patients in Class 3 would qualify for US Social Security benefits. Class 4 impairment describes individuals who have symptoms during ordinary activity and should have signs or laboratory evidence of cardiac enlargement and abnormal ventricular function. For each class, the AMA Guides describes a range of impairment ratings and provides examples.

Impaired Cardiopulmonary Exercise Capacity in Patients With Hyperthyroidism

Hyperthyroidism (H) has been implicated as a primary cause of decreased exercise tolerance. To our knowledge, analysis of respiratory gas exchange, an efficient noninvasive method in evaluating cardiopulmonary capacity, has not been performed in patients with H. Using cardiopulmonary exercise testing, 12 consecutive women with Graves' H were examined and controlled in euthyroidism (E). Eighteen women with E, in whom cardiac catheterization had ruled out heart disease, served as control subjects (C). The ventilatory anaerobic threshold was determined by means of the V-slope method. Ergometry was performed with patients in a semisupine position using a continuous ramp protocol of 20 W/min. Echocardiography at rest was performed in all patients. In patients with H, heart rate at rest was higher than in patients with E (p < 0.05) and showed a markedly lower increase between rest and anaerobic threshold compared with E patients (p = 0.007) and C (p = 0.009). Work rate was reduced (H, 50% vs E, 70%; p = 0.038). In H patients, the anaerobic threshold occurred at 59.6% of maximal oxygen uptake and 72% in E patients, respectively (p = 0.024). In H patients, the linear regression of the heart rate to oxygen uptake ratio showed a reduced slope in comparison with E patients (p = 0.001) and C (p = 0.004). In patients with H, a reduced tidal volume (p = 0.021) and an increased respiratory rate (p = 0.003) in comparison to patients with E were demonstrated. Echocardiographically, H patients had an increased ejection fraction (p = 0.008) and a higher cardiac index (p = 0.008) in comparison with E patients. Analysis of respiratory gas exchange showed marked alterations of cardiopulmonary exercise capacity in H patients, which are reversible in E patients. The impaired chronotropic response during exercise might be the primary limiting factor of reduced work capacity in patients with H.

Physical working capacity after acute myocardial infarction in patients with low ejection fraction and effect of captopril

Previous studies after acute myocardial infarction (AMI) have reported conflicting results on the effects of angiotensin-converring enzyme inhibition on physical working capacity. In an effort to provide more insight into this subject, we examined the effects of captopril on working capacity of patients who had low ejection fractions but no congestive heart failure after AMI. One hundred sixty-six participants were recruited from 5 centers after randomization to either captopril or placebo for the Survival and Ventricular Enlargement study. Upright cycle ergometer tests were performed with continuous measurements of respiratory gases at 4, 12, and 24 months after AMI. Our study concurs with 2 of 3 previous post-AMI studies and supports the conclusion that working capacity is not affected by angio-tensin-converring enzyme inhibition at 4 or 12 months after AMI in patients without congestive heart failure. In addition, no significant effect of captopril was noted at 24 months after AMI. Peak oxygen uptake tended to decrease between 12 and 24 months in the placebo group by an average (± SD) of −22 ± 322 ml/min (n = 66), but to increase in the captopril group (+62 ± 289, n = 57), a difference that was significant (Mann-Whitney chi-square, p = 0.02). This post-hoc observation suggests that a late beneficial effect may have been masked by inadequate study duration. Known benefits of captopril appear not to include an increase in working capacity within the first 24 months after AMI.

Eight‐year survival and functional work capacity of patients with normal or near normal coronary arteriograms

The clinical and laboratory course of 68 men with chest pain suggestive of coronary heart disease with normal or narrow wall irregularities only on coronary arteriograms was followed for 5 to 11.7 years. In all patients graded bicycle exercise test was stopped at a symptom‐ or a sign‐limited endpoint of work, and coronary arteriography was performed. Fifty patients were reexamined 8.4 ± 2.4 years later by the work stress test only. On reevaluation, there was no significant difference in mean tolerated power output, in limiting oxygen consumption, or in limiting heart rate. Mean values of systolic and diastolic blood pressure both at rest and at the limiting symptoms for work and the mean limiting value of the rate‐pressure product index were significantly higher on reevaluation (p ≤ 0.02 to 0.001). However, the mean limiting value of lactic acid was significantly lower (p ≤ 0.001). On reevaluation, 23 patients (46%) reported clinical improvement, 16 (32%) no change, and 11 (22%) complained of worsening of...

Endoscopic transthoracic sympathicotomy for severe angina.

We evaluated the antianginal effects of endoscopic transthoracic sympathicotomy (ETS) in 24 patients not eligible for coronary bypass surgery or angioplasty. In this procedure, the sympathetic chain is electrocoagulated under general anaesthesia. No major surgical complications occurred. The frequency of anginal attacks was significantly reduced (p = 0.001). The mean increase in maximum exercise capacity was 13 (SD 21) W (p = 0.009). ST depression at maximum comparable workload was reduced by 0.052 (0.10) mV (p = 0.005). Global ejection fraction during exercise and metaiodobenzylguanidine uptake were unchanged. Heart rate variability analysis showed a reduction of the ratio between low and high frequencies at tilt test (-1.00 [0.96]; p < 0.001). We conclude that ETS can be done without major complications, alleviates angina, and increases maximum working capacity in patients with advanced coronary disease.

Aerobic work capacity in patients with chronic fatigue syndrome.

To determine the aerobic work capacity of patients with the chronic fatigue syndrome and compare it with that of two control groups, and to assess the patients' perception of their level of activity before and during illness. A symptom limited exercise treadmill test with on line gas analysis and blood sampling was used. Subjects were assessed by one investigator, who was blind to the group which they were in. Department of medicine, Royal Victoria Hospital, Belfast. 13 Patients (10 women, three men) who fulfilled the diagnostic criteria for chronic fatigue syndrome. Two control groups of similar age, sex, and body weight: 13 normal subjects (10 women, three men) and seven patients (five women, two men) with the irritable bowel syndrome. Aerobic work capacity as assessed by several variables such as length of time on treadmill, heart rate, and biochemical measurements; Borg score; and visual analogue scores of perceived level of physical activity. The patients with the chronic fatigue syndrome had a reduced exercise capacity compared with that of the other subjects, spending a significantly shorter time on the treadmill. They had a significantly higher heart rate at submaximal levels of exertion and at stage III exertion had significantly higher blood lactate concentrations. Using a Borg score, they showed a significantly altered perception of their degree of physical exertion with a mean score of 8.2 compared with 6.6 and 5.3 for the normal subjects and patients with the irritable bowel syndrome respectively. Using a visual analogue scale they indicated that they had a greater capacity for activity before illness than had the patients with the irritable bowel syndrome, but the scores were not significantly different between the two groups. Both groups of patients indicated reduced activity at the time of testing. Normal controls and patients with the irritable bowel syndrome aspired to a greater level of activity than their current level, but the patients with the chronic fatigue syndrome aspired to a level similar to that which they had had before their illness. Patients with the chronic fatigue syndrome have reduced aerobic work capacity compared with normal subjects and patients with the irritable bowel syndrome. They also have an altered perception of their degree of exertion and their premorbid level of physical activity.

Task force II: Determination of occupational working capacity in patients with ischemic heart disease

The physical, metabolic and cardiovascular demands of occupations in industrialized countries have substantially declined during the past century. Many jobs that once required substantial physical effort are now performed by machines, robots or computers. This decrease in job-related energy demand is especially apparent in occupations performed by people over age 40, who, given some seniority, rarely perform physical tasks exceeding a peak energy expenditure of 5 kcaVmin or 3.5 METS, where 1 MET = energy expenditure sitting at rest (I). Nonetheless, the physical stress of employment is still the greatest challenge to the cardiovascular system of many patients with ischemic heart disease. For many sedentary jobs posing limited psychological or environmental demands, the adequacy of the patient’s physical working capacity can be assessed by a medical history, physical examination and symptom-limited exercise testing. However, as the physical demands of the job tasks increase to include exercise of widely varying intensities and types, or substantial psychological or environmental stress, assessment of physical working capacity becomes more complex. In patients with ischemic heart disease, the focus of occupational work evaluation is to determine whether or not the increase in cardiac demands produced by physical, psychological and environmental stressors will exceed the threshold for a “safe working capacity.” The challenge to the physician is to obtain an accurate, valid and reliable determination of this capacity.

Acute and chronic effects of molsidomine on pulmonary artery pressure and work capacity in patients with coronary heart disease.

To test the clinically supposed development of tolerance during chronic molsidomine therapy we studied a total of 11 patients with angiographically-proven coronary heart disease at rest and during ergometric exercise (supine position; submaximal, i.e. 50 W for 3 min, and maximal exercise). Pulmonary arterial pressure (PAPmean, floating catheter), arterial blood pressure (RR, cuff method), work capacity (W x min) and duration of exercise loading (sec) were measured at rest and on exercise before and during chronic (4 weeks) oral therapy with 3 x 4 mg day-1 of molsidomine. Acute administration of 4 mg molsidomine reduced the mean arterial resting pressure by 12% and under submaximal exercise loading by 8%. After molsidomine, the PAPmean was reduced by 35% at rest; following a period of treatment of 4 weeks no significant decrease in efficacy could be discerned (PAPmean reduction by 31%). Under submaximal and maximal exercise the PAPmean dropped by 44% and 37%, respectively (35.5 +/- 6.7 cf. 19.9 +/- 4.5 mmHg; 39.2 +/- 6.5 cf. 24.8 +/- 7.0 mmHg), whilst simultaneously the work capacity increased by 93% (281 +/- 108 cf. 545 +/- 254 W x min). After 4 weeks treatment with 12 mg day-1 of molsidomine, the PAPmean of 22.4 +/- 6.6 mmHg and 30.1 +/- 9.9 mmHg under identical exercise loading conditions, remained significantly below the exercise load value prior to the onset of medication. The molsidomine-induced increase in the exercise tolerance was maintained throughout the long-term medication (537 +/- 268 W x min). With a four-week treatment with daily doses of molsidomine there was a persistent effect on the pulmonary arterial pressure and the work capacity. Thus development of tolerance during high dose, long-term molsidomine therapy is not to be expected.