Responses of people with coronary artery disease to common lawn-care tasks.

The primary purpose of the present study was to determine oxygen uptake (VO2) and heart rate (HR) responses of patients with coronary artery disease (CAD) to common lawn-care activities. The study was conducted in three phases. In phase I, 8 men with CAD performed 30 min of push motorized lawn mowing at a self-paced rate. In phase II, 9 men with CAD performed push (no power) mowing, trimming (power and manual), and raking for 8 min each. In phase III, age-matched men and women with and without CAD (9-11 per group) performed self-propelled motorized mowing and push motorized mowing. In phase I, VO2 averaged 17.3 (SEM 3.8) ml.kg-1.min-1 during 30 min of mowing. Relative effort was 68 (SEM 1) and 76 (SEM 4)% of treadmill maximal VO2 (VO2max) and HR, respectively. In phase II, mean VO2 ranged from 8.6 (SEM 0.4) with grass trimming to 22.2 (SEM 1.6) ml.kg-1.min-1 with push manual mowing. With self-propelled mowing at three speeds in phase III, mean VO2 of the CAD groups ranged from 9.5 (SEM 0.3) to 13.8 (SEM 1.4) ml.kg-1.min-1 and represented 37%-62% VO2max. The results indicated that lawn mowing is often performed at an exercise intensity recommended for aerobic exercise training; patients who achieve a treadmill peak capacity of 4 times resting metabolic rate (4 METs) should be able to perform self-propelled motorized lawn mowing (slow speed) and grass trimming at less than 80% peak VO2; and VO2 demands of lawn mowing can be adjusted by equipment selection and/or pace.

Energy expenditure during household tasks in women with coronary artery disease.

The energy expenditure for and heart rate responses to common household tasks were determined in 26 older (mean age 62 +/- 2 years) women with coronary artery disease (CAD). Each activity was performed at a self-determined pace for 6 or 8 minutes. The average oxygen uptake (ml/kg/min) for each task evaluated was 6.5 for washing dishes, 6.8 for ironing, 7.2 for scrubbing pans, 8.6 for unpacking groceries, 9.5 for vacuuming, 9.8 for sweeping, 10.1 for mopping, 12.0 for changing bed linens, and 12.4 for washing the floor (hands and knees). None of the subjects reported angina. Mean relative oxygen uptake (i.e., percentage of peak response with treadmill testing) ranged from 31 +/- 2% for washing dishes to 62 +/- 3% for changing the bed linens and washing the floor. Percentage of peak treadmill heart rate ranged from 62 +/- 2% for washing dishes to 73 +/- 2% for washing the floor. In 4 of the more physically demanding household activities (i.e., vacuuming, mopping, washing the floor, and changing bed linens), the responses of 10 age-matched normal women were evaluated. The absolute and relative demands of the tasks were similar between the CAD and normal groups. Results indicate that the mean energy expenditure rate of common household tasks evaluated in this study range from 2 to 4 METs, suggesting that most women with CAD who are able to achieve > or = 5 METs during a treadmill exercise test without adverse signs or symptoms should be able to resume these activities.

Physiologic responses to shoveling and thermal stress in men with cardiac disease.

To investigate the effect of temperature stress on responses to static-dynamic work in patients with ischemic heart disease (IHD), 10 men with IHD shoveled gravel for 30 min in a warm (29 degrees C), neutral (24 degrees C), and cold (-8 degrees C) environment (on separate days). A pace of 15 lifts.min-1 was set, and the load per lift approximated 5.5 kg. Heart rate (HR), oxygen consumption (VO2), and systolic (SBP) and diastolic blood pressures (DBP) were evaluated at 5-min intervals. Arrhythmias and ST-segment depression were evaluated by ambulatory electrocardiographic monitoring. At 30 min, VO2, SBP, and DBP were higher (P < 0.05) in the cold environment, and HR was higher (P < 0.05) in the warm environment compared with the neutral environment. HR increased (P < 0.05) from 5 to 30 min in all three conditions. The increase in HR was greater (P < 0.05) in the warm environment. None of the subjects reported angina or demonstrated electrocardiographic ST-segment changes during shoveling in any environment. The results indicate that low-risk patients with stable IHD show modest temperature-induced alterations in hemodynamic and VO2 responses during 30 min of moderate intensity (50-60% of peak VO2) static-dynamic work without adverse electrocardiographic responses or symptomatology.

Baltimore Therapeutic Equipment work simulator: energy expenditure of work activities in cardiac patients.

The energy expenditure and hemodynamic responses to tasks performed on the Baltimore Therapeutic Equipment (BTE) work simulator were evaluated in men with coronary artery disease and compared to tasks performed at a laboratory workstation in which actual tools and equipment were used. Met units for the BTE work simulator and corresponding workstation tasks, respectively, were drill press operation, 1.5 +/- 0.1 and 1.5 +/- 0.3Mets; hammering, 2.3 +/- 0.3 and 3.4 +/- 0.8Mets (p < 0.05); repetitive lifting a 22.7kg weight load, 3.8 +/- 0.6 and 4.5 +/- 0.9Mets (p < 0.05); mechanic work in a supine position, 2.0 +/- 0.5 and 1.7 +/- 0.2Mets; sanding wood, 2.0 +/- 0.3 and 2.5 +/- 0.7Mets; sawing wood, 3.2 +/- 0.6 and 4.3 +/- 0.7Mets (p < 0.05); screwdriving, 2.2 +/- 0.3 and 2.5 +/- 0.5Mets (p < 0.05); shoveling, 5.45kg load 4.6 +/- 1.0 and 4.2 +/- 0.7Mets; sweeping, 1.7 +/- 0.2 and 3.0 +/- 0.4Mets (p < 0.05); and vacuuming, 2.7 +/- 0.7 and 2.9 +/- 0.5Mets. The results indicate that there is a tendency for the metabolic and hemodynamic responses to BTE work simulator tasks to be lower than that of the actual activity.

Medicare prospective payment without separate urban and rural rates.

The elimination of urban-rural differences in the Medicare prospective payment system (PPS) standard rates implies a need to re-examine all the PPS payment adjustments. Refinements for case mix, outliers, and the wage index can make a significant contribution to avoiding payment disparities in a single-rate system. However, changes in the adjustments for teaching and disproportionate-share (DSH) hospitals are also needed. The typically urban location of these hospitals makes it difficult to balance PPS payments and costs among major groups of urban and rural hospitals without some form of higher payment for all hospitals located in large urban areas.

Effect of age and coronary artery disease on response to snow shoveling.

OBJECTIVES: The objective of this study was to evaluate the effect of age and coronary artery disease on responses to snow shoveling. BACKGROUND: Little information is available on the hemodynamic and metabolic responses to snow shoveling. METHODS: Sixteen men with asymptomatic coronary artery disease and relatively good functional work capacity, 13 older normal men and 12 younger normal men shoveled snow at a self-paced rate. Oxygen consumption, heart rate and blood pressure were determined. In nine men with coronary artery disease left ventricular ejection fraction was evaluated with an ambulatory radionuclide recorder. RESULTS: Oxygen consumption during snow shoveling differed (p < 0.05) among groups; it was lowest (18.5 +/- 0.8 ml/kg per min) in those with coronary artery disease, intermediate (22.2 +/- 0.9 ml/kg/min) in older normal men and highest (25.6 +/- 1.3 ml/kg/min) in younger normal men. Percent peak treadmill oxygen consumption and heart rate with shoveling in the three groups ranged from 60% to 68% and 75% to 78%, respectively. Left ventricular ejection fraction and frequency of arrhythmias during shoveling were similar to those during treadmill testing. CONCLUSIONS: During snow shoveling 1) the rate of energy expenditure selected varied in relation to each man's peak oxygen consumption; 2) older and younger normal men and asymptomatic men with coronary artery disease paced themselves at similar relative work intensities; 3) the work intensity selected represented hard work but was within commonly recommended criteria for aerobic exercise training; and 4) arrhythmias and left ventricular ejection fraction were similar to those associated with dynamic exercise.

Is very fresh blood needed in preparing leukocyte-poor red blood cells by inverted centrifugation?

It is recommended that units selected for inverted centrifugal preparation of leukocyte-poor red blood cells be less than 24 hours old. The reason for this is unclear and the recommendation poses practical problems. We evaluated the effectiveness of inverted centrifugation in reducing the WBC:RBC ratio in 31 units stored up to six days at 4 C. Leukocyte removal was at least as effective with six-day stored units as with less than one day old, averaging 77 per cent reduction with 76 per cent recovery of red blood cells. No reduction in leukocytes occurred with six days storage alone. It appears to be unnecessary to restrict leukocyte removal by inverted centrifugation to units less than 24 hours old.