1: J Am Geriatr Soc. 2004 Dec;52(12):2099-103. Use of self-report to predict ability to walk 400 meters in mobility-limited older adults. Sayers SP, Brach JS, Newman AB, Heeren TC, Guralnik JM, Fielding RA. Human Physiology Laboratory, Department of Health Sciences, Sargent College of Rehabilitation Sciences, Boston, Massachusetts, USA. sayerss@missouri.edu OBJECTIVES: To determine whether the ability to walk 400 m could be predicted from self-reported walking habits and abilities in older adults and to develop an accurate self-report measure appropriate for observational trials of mobility when functional measures are impractical to collect. DESIGN: Cross-sectional. SETTING: University-based human physiology laboratory. PARTICIPANTS: One hundred fifty community-dwelling older men and women (mean age+/-standard error= 79.8+/-0.3). MEASUREMENTS: An 18-item questionnaire assessing walking habits and ability was administered to each participant, followed by a 400-m walk test. Ninety-eight (65%) volunteers were able to complete the 400-m walk; 52 (35%) were unable. Logistic regression was performed using response items from a questionnaire as predictors and 400-m walk as the outcome. RESULTS: Three questions (Do you think you could walk one-quarter of a mile now without sitting down to rest. Because of a health or physical problem, do you have difficulty walking 1 mile? Could you walk up and down every aisle of a grocery store without sitting down to rest or leaning on a cart?) were predictive of 400-m walking ability and were included in the model. If participants answered all three questions compatible with the inability to walk 400 m, there was a 91% probability that they were unable to walk 400 m, with a sensitivity of 46% and a specificity of 97%. CONCLUSION: A three-item self-report developed in the study was able to accurately predict mobility disability. The utility of this instrument may be in evaluating self-reported mobility in large observational trials on mobility when functional mobility tasks are impractical to collect. Publication Types: Evaluation Studies PMID: 15571550 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 2: J Sci Med Sport. 2004 Mar;7(1):11-22. Accuracy and reliability of a Cosmed K4b2 portable gas analysis system. Duffield R, Dawson B, Pinnington HC, Wong P. School of Human Movement and Exercise Science, University of Western Australia, Crawley, Western Australia. The purpose of this study was to assess the validity and reliability of a Cosmed K4b2 portable telemetric gas analysis system. Twelve physically fit males performed a treadmill running session consisting of an easy 10 min run, a hard 3 min run and a 1 min sprint (with rest periods of 10 min separating each run), on four separate occasions. Sessions were identical with the exception of the apparatus used to measure VO2. During two (test-retest) sessions a Cosmed K4b2 portable gas analysis system was used; in another, a laboratory metabolic cart and, in one session, both systems were used to measure VO2 simultaneously. Comparison of Cosmed K4b2 and metabolic cart measurements in isolation revealed significantly (p < 0.05) increased values of VO2, VCO2, FE CO2 (except FE CO2 at 10 min) and lower values of FE O2 for each run duration by the Cosmed system. Linear regression equations to predict metabolic cart results from Cosmed values were, respectively; cart VO2 = 0.926 (Cosmed VO2-0.227 (r2 = 0.84) and cart VCO2 = 1.057 (Cosmed VCO2-0.606 (r2 = 0.92). Bland-Altman plots and comparison of the test-retest cosmed measurements revealed that the K4b2 system showed good repeatability of measurement for measures of VE, VO2 and VCO2, particularly for 10 min and 3 min tests (ICC = 0.7-0.9, p < 0.05). In conclusion, the Cosmed K4b2 portable gas analysis system recorded consistently higher VO2 and VCO2 measurements in comparison to a metabolic cart. However, satisfactory test-retest reliability of the system was demonstrated. Publication Types: Validation Studies PMID: 15139160 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 3: Exp Brain Res. 2003 Apr;149(3):312-9. Epub 2003 Jan 31. Intermanual transfer of force control is modulated by asymmetry of muscular strength. Teixeira LA, Caminha LQ. School of Physical Education and Sport, University of Sao Paulo, Brazil. lateixei@usp.br Interlateral transfer of learning is conceptualized as an index of the degree to which learning takes place at a lower level of motor control, with strong dependence on the effector system, or at a higher effector-independent level in the movement organization hierarchy. In this study, the locus of motor learning was investigated by increasing lateral asymmetry of force between the wrist flexor muscles, and comparing the amount of interlateral transfer of force control in relation to a condition of symmetric force. To perform this contrast, the participants were assigned to one of three groups: symmetric force (SM), who were left with original asymmetries of muscular strength; asymmetric force (AS), who had unilateral training for increment of maximum strength for the wrist flexor muscles; or a control condition (CO). The learning task consisted of launching a small cart across a metallic trackway with the preferred hand, aiming at making the cart achieve an instantaneous velocity of 70 cm/s. This action was practiced for 300 trials by the SM and AS group, while the CO group had active rest. The groups, then, were submitted to a transfer task requiring a mirrored action with the contralateral hand. The results indicated that the SM group achieved significantly higher interlateral transfer of learning as compared to the AS group, which presented response variability similar to the CO group. Analysis of directional trend of error revealed that the AS group presented a significant target overshoot as compared with the symmetric force groups. These findings suggest that an absolute force is learnt at a higher level in the action hierarchy, and that decline in interlateral transfer of learning in the asymmetric force condition was motivated by a resetting in the interplay between higher and lower levels of movement control. PMID: 12632233 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 4: Crit Care Med. 2003 Mar;31(3):830-3. Quantitative analysis of the relationship between sedation and resting energy expenditure in postoperative patients. Terao Y, Miura K, Saito M, Sekino M, Fukusaki M, Sumikawa K. Department of Anesthesiology, Nagasaki University School of Medicine, Japan. eisuketerao@aol.com OBJECTIVE: To analyze quantitatively the relationship between sedation and resting energy expenditure or oxygen consumption in postoperative patients. DESIGN: A prospective, clinical study. SETTING: An eight-bed intensive care unit at a university hospital. PATIENTS: Thirty-two postoperative patients undergoing either esophagectomy or surgery of malignant tumors of the head and neck who required mechanical ventilation and sedation for > or = 2 days postoperatively. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 133 metabolic measurements were performed. Ramsay sedation scale (RSS), body temperature, and the dose of midazolam were evaluated at the time of the metabolic cart study. All patients received analgesia with buprenorphine at a fixed dose of 0.625 microg x kg(-1) x hr(-1) continuously. Midazolam was used for induction and maintenance of intravenous sedation after admission to the intensive care unit. The initial dose was 0.04 mg x kg(-1) x hr(-1) and was adjusted to achieve a desired depth of sedation at 3, 4, or 5 on the RSS every 4 hrs. The degree of sedation was classified into three states: light sedation (RSS 2-3; n = 49), moderate sedation (RSS 4; n = 39), and heavy sedation (RSS 5-6; n = 45). RESULTS: With increasing the depth of sedation, oxygen consumption index (mL x min(-1) x m(-2)), resting energy expenditure index (REEI; kcal x day(-1) x m(-2)), and REE/basal energy expenditure (BEE) decreased significantly. Oxygen consumption index (mean +/- SD), REEI, and REE/BEE were 151 +/- 18, 1032 +/- 120, and 1.29 +/- 0.17 in the light sedation, 139 +/- 22, 947 +/- 143, and 1.20 +/- 0.16 in the moderate sedation, and 125 +/- 16, 865 +/- 105, and 1.13 +/- 0.12 in the heavy sedation, respectively. CONCLUSION: An increase in the depth of sedation progressively decreases in oxygen consumption index and REEI in postoperative patients. PMID: 12626992 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 5: Diabetes. 2001 Sep;50(9):2157-60. Mutational screening of the CART gene in obese children: identifying a mutation (Leu34Phe) associated with reduced resting energy expenditure and cosegregating with obesity phenotype in a large family. del Giudice EM, Santoro N, Cirillo G, D'Urso L, Di Toro R, Perrone L. Department of Pediatrics, Second University of Naples, Naples, Italy. emanuele.miraglia@unina2.it Cocaine- and amphetamine-regulated transcript (CART) inhibits feeding and induces the expression of c-Fos in hypothalamic areas implicated in appetite regulation. Furthermore, the CART peptide is found in neurons regulating sympathetic outflow, which in turn play an integral role in regulating body temperature and energy expenditure. The CART gene was screened by single-strand conformation polymorphism and automatic sequencing in 130 (72 girls) unrelated obese Italian children and adolescents. Their Z-scores (mean +/- SD) of relative to BMI percentiles was 3.9 +/- 1.8, and the average age at obesity onset was 4.7 +/- 2.6 years. Two previously described silent polymorphisms were found in the 3' untranslated region: an adenine deletion at position 1457 in 9 patients (allele frequency 0.035) and an A/G substitution at position 1475 in 11 patients (allele frequency 0.042). We found no difference between the obese patients heterozygous for one of these polymorphisms and those patients homozygous for the wild allele with respect to their age of obesity onset, BMI Z-scores, and leptin levels. A missense mutation of G729C resulting in the substitution of Leu with Phe at codon 34, within the NH2-terminal CART region, has been detected in the heterozygous state in a 10-year-old obese boy who has been obese since the age of 2 years. The patient belongs to a large family of obese subjects. The mutation cosegregated with the severe obesity phenotype over three generations and was not found in the control population. Resting metabolic rates were lower than expected in the propositus (-14%) and his mother (-16%), who carried the mutation. Leucine at codon 34, conserved in this position in the human and in the rat sequences, immediately precedes a couple of lysine residues that may well represent a dibasic processing site. The Leu34Phe mutation might alter the susceptibility to proteolysis of this potential processing site, likely altering the CART effect on thermogenesis and energy expenditure. PMID: 11522684 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 6: Pflugers Arch. 2001 Jun;442(3):443-50. Oxygen delivery and oxygen return in humans exercising in acute normobaric hypoxia. Anchisi S, Moia C, Ferretti G. Departement de Physiologie, Centre Medical Universitaire, Geneve 4, Switzerland. At a given steady O2 consumption (VO2) in normoxia, cardiac output (Q) is inversely proportional to arterial O2 concentration (CaO2), so that O2 delivery (QaO2=QCaO2) is kept constant and adapted to VO2. The matching between QaO2 and VO2 keeps O2 return (QvO2=QaO2-VO2) constant and independent of VO2 and haemoglobin concentration ([Hb]). This may not be so in hypoxia: in order for QvO2 to be independent of the inspired O2 fractions (FIO2), the slopes of the Q versus VO2 lines should be greater the lower the CaO2, which may not be the case. Thus, we tested the hypothesis of constant QvO2 by determining QaO2 and QvO2 in acute hypoxia. Thirteen subjects performed steady-state submaximal exercise on the cycle ergometer at 30, 60, 90 and 120 W breathing FIO2 of 0.21, 0.16, 0.13, 0.11 and 0.09. VO2 was measured by a metabolic cart, Q by CO2 rebreathing, [Hb] by a photometric technique and arterial O2, saturation (SaO2) by infrared oximetry. CaO2 was calculated from [Hb], SaO2 and the O2 binding coefficient of haemoglobin. The VO2 versus power relation was independent of FIO2. The relations between Q and VO2 were displaced upward and had higher slopes in hypoxia than in normoxia. However, the Q changes did not compensate for those in CaO2. The slopes of the QaO2 versus VO2, lines tended to decrease in hypoxia. QVO2 was lower the lower the FIO2. A significant relationship was found between QvO2 and SaO2 (QvO2= 1.442 SaO2+0.107, r=0.871, n=24, P<10(-7)), which confutes the hypothesis of constant QvO2 in hypoxia. PMID: 11484777 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 7: Spinal Cord. 2000 Oct;38(10):630-8. Quadriceps muscle deoxygenation during functional electrical stimulation in adults with spinal cord injury. Bhambhani Y, Tuchak C, Burnham R, Jeon J, Maikala R. Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Canada, T6G 2G4. STUDY DESIGN: Cross-sectional study comparing healthy subjects with age and gender matched subjects with spinal cord injury (SCI, injury levels from C5 to T12). OBJECTIVES: To compare the acute cardiorespiratory responses and muscle oxygenation trends during functional electrical stimulation (FES) cycle exercise and recovery in the SCI and healthy subjects exercising on a mechanical cycle ergometer. SETTING: Seven volunteers in each group participated in one exercise test at the Rick Hansen Center, University of Alberta, Edmonton, Canada. METHODS: Both groups completed a stagewise incremental test to voluntary fatigue followed by 2 min each of active and passive recovery. Cardiorespiratory responses were continuously monitored using an automated metabolic cart and a wireless heart rate monitor. Tissue absorbency, an index of muscle oxygenation, was monitored non-invasively from the vastus lateralis using near infrared spectroscopy. RESULTS: The healthy subjects showed significant (P<0.05) increases in the oxygen uptake (VO2), heart rate (HR) and ventilation rate (VE) from rest to maximal exercise. The SCI subjects showed a twofold increase in VO2 (P>0.05), a threefold increase in VE (P<0.05) and a 5 beats/min increase in HR (P>0.05) from the resting value. The SCI subjects demonstrated a lesser degree (P<0.05) of muscle deoxygenation than the healthy subjects during the transition from rest to exercise. Regression analysis indicated that the rate of decline in muscle deoxygenation with respect to the VO2 was significantly (P<0.05) faster in the SCI subjects compared to healthy subjects. CONCLUSIONS: FES exercise in SCI subjects elicits: (a) modest increases in the cardiorespiratory responses when compared to resting levels; (b) lower degree of muscle deoxygenation during maximal exercise, and (c) faster changes in muscle deoxygenation with respect to the VO2 during exercise when compared to healthy subjects. PMID: 11093325 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 8: J Sports Med Phys Fitness. 1999 Dec;39(4):321-7. Physical activity level during a round of golf on a hilly course. Stauch M, Liu Y, Giesler M, Lehmann M. Department of Sports Medicine, Medizinische Universitatsklinik Ulm, Germany. BACKGROUND: Regular physical activity plays a role in preventive medicine. Our study aimed at establishing the duration of different levels of exercise intensity during a round of golf. METHODS: Participants: we studied 21 male and 9 female golfers (mean age 53 +/- 11 and 54 +/- 13 years respectively) volunteering for a round of golf on a hilly course. Measures: we recorded mean heart rate (HR) of every 15 seconds. Blood pressure was taken on each tee. Maximum HR (HRmax) reserve of each subject was calculated from the difference between pre-exercise and maximum HR attained during a test to volitional exhaustion on a cycle ergometer. A percentage of this value was added to the resting HR and was expressed as a percentage of HRmax reserve. RESULTS: Before start mean HR (+/- SD) was 86 +/- 11 beats per minute (BPM), during play 113 +/- 18, and during rest after play 100 +/- 24 BPM. Mean maximal HR of holes were 135 +/- 21 BPM. Mean systolic blood pressure was 145 +/- 30 before play, 137 +/- 31 on tees during play and 119 +/- 15 mmHg after play. A mean of 82 +/- 51 minutes was spent at 50-74% of HRmax reserve. 21 +/- 27 and 23 +/- 38 minutes were spent in the two higher intensity classes. An average of 106 +/- 77 minutes were spent at or above the individual heart rate equivalent of 100 W, the mean heart rate for this time was 128 +/- 17 BPM. Creatine kinase (+47%; p < 0.001), uric acid (+9%; p < 0.001) and HDL-cholesterol (+6%; p < 0.05) increased, triglycerides decreased by 18% (p < 0.01). CONCLUSIONS: The HR level during the golfround not using an electric cart relative to the maximum attained on the ergometer reaches the exercise intensity of 50 to > 85% HRmax reserve for a mean of over 2 hours, much longer than the 20-60 min recommended for endurance training. PMID: 10726433 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 9: Am J Respir Crit Care Med. 2000 Mar;161(3 Pt 1):880-5. Respiratory muscle recruitment and exercise performance in eucapnic and hypercapnic severe chronic obstructive pulmonary disease. Montes de Oca M, Celli BR. Division of Pulmonary and Critical Care Medicine, St. Elizabeth's Medical Center, Tufts University, Boston, Massachusetts 02135, USA. If chronic hypercapnia in patients with severe COPD occurs as a consequence of respiratory muscle (RM) weakness or fatigue, we would expect that ventilatory muscle recruitment (VMR) and exercise performance in stable hypercapnic patients would differ from those in eucapnic patients. We evaluated exercise performance and RM function at rest and during exercise in 19 eucapnic (PCO(2) 40 +/- 3 mm Hg), and 13 hypercapnic (PCO(2) 52 +/- 10 mm Hg) patients with severe COPD. A metabolic cart was used to determine V E, V O(2), V CO(2), and HR. Gastric (Pg) and esophageal (Ppl) balloons were used to measure Pg, Ppl, and Pdi. Ventilatory muscle recruitment pattern (VMR) was partitioned using end-inspiratory and end-expiratory Pg and Ppl. Hypercapnic patients had lower FEV(1) (0.60 +/- 0.24 versus 0.95 +/- 0.31 L, p < 0.001), MVV (28 +/- 11 versus 41 +/- 13 L, p < 0.001), resting PO(2) (61 +/- 11 versus 70 +/- 11 mm Hg, p < 0.001), peak PO(2) (60 +/- 20 versus 75 +/- 22 mm Hg, p < 0.005), and V E(max) (24 +/- 10 versus 32 +/- 12 L/min, p < 0.001). Patients in both groups had similar FRC (5.7 +/- 1.6 versus 5.0 +/- 1.5 L), V O(2)max (0.58 +/- 0.30 versus 0.76 +/- 0.32 L/min), Watts (45 +/- 48 versus 71 +/- 59), V E/MVV (88 +/- 33 versus 79 +/- 14), and HRmax (117 +/- 17 versus 128 +/- 18 beats/min). PI(max) (67 +/- 28 versus 65 +/- 32 cm H(2)O) and PE(max) (98 +/- 34 versus 96 +/- 40 cm H(2)O) were also similar in both groups. VMR (DeltaPg/DeltaPpl) at rest (-0.28 +/- 0.51 versus 0 +/- 0.35) and during exercise (0.4 +/- 0.2 versus 0.39 +/- 0.15) was equally affected in both groups. We conclude that exercise capacity and ventilatory muscle recruitment are similarly impaired in eucapnic and hypercapnic patients with severe COPD. These findings make inability of the lung to increase ventilation and not respiratory muscle dysfunction a more attractive explanation for CO(2) retention in stable hypercapnic patients. PMID: 10712337 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 10: Arch Phys Med Rehabil. 2000 Jan;81(1):102-9. Endurance training in patients with chronic obstructive pulmonary disease: a comparison of high versus moderate intensity. Gimenez M, Servera E, Vergara P, Bach JR, Polu JM. Laboratoire de Physiologie de L'Exercice Musculaire, Unite 14 of the Institut Nationale de la Sante et de la Recherche Medicale, Nancy, France. PURPOSE: To create a maximum tolerated 45-minute aerobic training program for patients with chronic obstructive pulmonary disease (COPD) and to compare its outcomes with those of commonly prescribed moderate exercise. DESIGN: Prospective, randomized trial. SETTING: A work physiology laboratory. PATIENTS AND METHODS: The maximum exercise intensities that 7 COPD patients could sustain for 45 minutes were determined on a bilevel exercise ergometer. The patients then exercised 45 minutes daily, 5 days a week for 6 weeks, working 2.03+/-0.4 kJ/kg per session. They were matched with 6 COPD patients who pushed an O2 cart for 45 minutes daily, 5 days a week for 6 weeks, working 1.44+/-.35 kJ/kg per session. RESULTS: A 45 minute maximal regimen was established by alternating 1-minute peak exercise at peak VO2-levels with 4 minutes at the ventilatory anaerobic threshold or at 40% of peak VO2. Maximal bilevel training significantly decreased dyspnea at rest (p< or =.01) and the blood lactate level during submaximal exercise (p<.001), and increased peak VO2 and total physical work (p<.01), maximum inspiratory and expiratory pressures (p<.01), and grip and forearm strength and endurance (p<.01). The training also increased maximum voluntary ventilation while decreasing the ventilatory equivalent during exercise (p<.001). The O2 cart pushers significantly improved only on the 12-minute walk (p<.05). CONCLUSIONS: A maximally intense anaerobic exercise program can be created for most COPD patients that can significantly improve both skeletal and respiratory muscle strength and endurance as well as dyspnea and physiologic parameters. Publication Types: Clinical Trial Randomized Controlled Trial PMID: 10638884 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 11: Crit Care Med. 1999 Oct;27(10):2133-6. Comment in: Crit Care Med. 1999 Oct;27(10):2293-4. Evaluation of oxygen consumption and resting energy expenditure in critically ill patients with systemic inflammatory response syndrome. Moriyama S, Okamoto K, Tabira Y, Kikuta K, Kukita I, Hamaguchi M, Kitamura N. Division of Intensive and Critical Care Medicine, Kumamoto University School of Medicine, Kumamoto City, Japan. OBJECTIVE: To determine whether oxygen consumption VO2), CO2 production, and resting energy expenditure (REE) in critically ill patients differ in varying grades of systemic inflammatory response syndrome (SIRS). DESIGN: Prospective, clinical study. SETTING: Intensive care unit at a university hospital. PATIENTS: Twenty-six critically ill patients requiring mechanical ventilation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 100 metabolic measurements were performed. The grade of SIRS and the Acute Physiology and Chronic Health Evaluation II score were evaluated at the time of the metabolic cart study. VO2 and REE differed among the groups inadequate for SIRS (non-SIRS), with SIRS without infection (nonseptic SIRS), and with SIRS with infection (septic SIRS) (125 +/- 37 mL/min/m2 and 855 +/- 204 kcal/day/m2, 135 +/- 33 mL/min/m2 and 948 +/- 214 kcal/day/m2, and 166 +/- 55 mL/min/m2 and 1149 +/- 339 kcal/day/m2, respectively; p < .005). Patients with septic SIRS had higher VO2 and REE than patients with non-SIRS and nonseptic SIRS. CONCLUSION: VO2 and REE differ among groups of patients with non-SIRS, nonseptic SIRS, and septic SIRS. Patients with septic SIRS have higher VO2 and REE than patients with non-SIRS or nonseptic SIRS. The present study shows that classifying patients into three grades (non-SIRS, nonseptic SIRS, and septic SIRS) is a valid predictor of metabolic stress in critically ill patients. PMID: 10548194 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 12: J Am Coll Cardiol. 1999 Mar;33(3):708-16. Prognostic value of dobutamine stress echocardiography in predicting cardiac events in patients with known or suspected coronary artery disease. Krivokapich J, Child JS, Walter DO, Garfinkel A. Department of Medicine, UCLA School of Medicine, Los Angeles, California 90095-1679, USA. jkrivoka@medicine.medsch.ucla.edu OBJECTIVES: The study sought to determine the utility of dobutamine stress echocardiography (DSE) in predicting cardiac events in the year after testing. BACKGROUND: Increasingly, DSE has been applied to risk stratification of patients. METHODS: Medical records of 1,183 consecutive patients who underwent DSE were reviewed. The cardiac events that occurred during the 12 months after DSE were tabulated: myocardial infarction (MI), cardiac death, percutaneous transluminal coronary angioplasty (PTCA), and coronary artery bypass surgery (CABG). Patient exclusions included organ transplant receipt or evaluation, recent PTCA, noncardiac death, and lack of follow-up. A positive stress echocardiogram (SE) was defined as new or worsened wall-motion abnormalities (WMAs) consistent with ischemia during DSE. Classification and regression tree (CART) analysis identified variables that best predicted future cardiac events. RESULTS: The average age was 68+/-12 years, with 338 women and 220 men. The overall cardiac event rate was 34% if SE was positive, and 10% if it was negative. The event rates for MI and death were 10% and 8%, respectively, if SE was positive, and 3% and 3%, respectively, if SE was negative. If an ischemic electrocardiogram (ECG) and a positive SE were present, the overall event rate was 42%, versus a 7% rate when ECG and SE were negative for ischemia. Rest WMA was the most useful variable in predicting future cardiac events using CART: 25% of patients with and 6% without a rest WMA had an event. Other important variables were a dobutamine EF <52.5%, a positive SE, an ischemic ECG response, history of hypertension and age. CONCLUSIONS: A positive SE provides useful prognostic information that is enhanced by also considering rest-wall motion, stress ECG response, and dobutamine EF. PMID: 10080472 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 13: Chest. 1998 Apr;113(4):913-8. Breathing reserve at the lactate threshold to differentiate a pulmonary mechanical from cardiovascular limit to exercise. Medoff BD, Oelberg DA, Kanarek DJ, Systrom DM. Pulmonary and Critical Care Unit, Massachusetts General Hospital and Harvard Medical School, Boston 02114, USA. STUDY OBJECTIVES: Criteria used to define the respective roles of pulmonary mechanics and cardiovascular disease in limiting exercise performance are usually obtained at peak exercise, but are dependent on maximal patient effort. To differentiate heart from lung disease during a less effort-dependent domain of exercise, the predictive value of the breathing reserve index (BRI=minute ventilation [VE]/maximal voluntary ventilation [MVV]) at the lactate threshold (LT) was evaluated. DESIGN: Thirty-two patients with COPD and a pulmonary mechanical limit (PML) to exercise defined by classic criteria at maximum oxygen uptake (VO2max) were compared with 29 patients with a cardiovascular limit (CVL) and 12 normal control subjects. Expired gases and VE were measured breath by breath using a commercially available metabolic cart (Model 2001; MedGraphics Corp; St. Paul, Minn). Arterial blood gases, pH, and lactate were sampled each minute during exercise, and cardiac output (Q) was measured by first-pass radionuclide ventriculography (System 77; Baird Corp; Bedford, Mass) at rest and peak exercise. RESULTS: For all patients, the BRI at lactate threshold (BRILT) correlated with the BRI at VO2max (BRIMAX) (r=0.85, p<0.0001). The BRILT was higher for PML (0.73+/-0.03, mean+/-SEM) vs CVL (0.27+/-0.02, p<0.0001), and vs control subjects (0.24+/-0.03, p<0.0001). A BRILT > or = 0.42 predicted a PML at maximum exercise, with a sensitivity of 96.9%, a specificity of 95.1%, a positive predictive value of 93.9%, and a negative predictive value of 97.5%. CONCLUSIONS: The BRILT, a variable measured during the submaximal realm of exercise, can distinguish a PML from CVL. PMID: 9554625 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 14: J Healthc Resour Manag. 1997 Jun;15(5):11-8. The cost management organization: the next step for materiel management. Schuweiler RC. Group Health Cooperative of Puget Sound, Seattle, WA, USA. With Materiel Management's transition over the last decade from simple logistics to analysis and cost management, it has gained recognition as a key part of the management team responsible for supplies, equipment, standards, and associated processes to identify, purchase, store, distribute, issue, and dispose of supplies and equipment. The materiel manager's job consists of putting the right product in the right place at the right time and in the right quantity at the best total delivered cost. In this context, Materiel Management has made powerful impacts to lower costs associated with: Distribution--costs have been lowered by actively adopting advanced supply channel management techniques such as primary suppliers, JIT, stockless programs, case cart/custom kit/procedure based delivery systems, modified stockless programs as well as margin management through cost plus, flat fee, or margins paid per activity. Cost of goods--lowered through aggregated purchasing in the forms of regional and national purchasing alliances and local capitation or other gain/risk share programs. Internal process costs--lowered by out-sourcing and/or integrating supplier processes and personnel into operations via partnership approaches. We have also reduced transactional costs through EDI transaction sets and the emerging use of the inter and intranet/electronic commerce, procurement cards, and evaluated receipt settlement processes. De-layering--We have lowered the operating costs of Materiel Management overhead by re-design/re-engineering, resulting in reduced management and greater front line authority. Quality--We have learned to identify and respond to customer and supplier needs by using quality improvement tools and ongoing measurement and monitoring techniques. Through this we have identified the waste of non-beneficial products and services. We have adopted supplier certification measurers to ensure quality is built into processes and outcomes. With so much already accomplished, it should be easy to rest on these laurels and simply operate. However, we believe that this is just a beginning. A new generation of highly educated leaders are emerging and taking advantage of the contributions of pioneers who laid the ground work. These new leaders will have advanced management, statistics, and behavioral sciences skills. They will be analysts and organizational motivators. Their goal will be to improve financial and clinical performance measured by real time process and performance data. The new leaders will have information at their fingertips thanks to significant leaps forward in data collection, automated continuous replenishment processes, and software designed for better management of clinical and cost outcomes. This article documents significant Materiel management accomplishments and conceptualizes cost management processes. The cost management organization is the logical evolution in our efforts for better outcomes in healthcare Materiel management. PMID: 10168654 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 15: Arch Environ Health. 1996 Mar-Apr;51(2):138-45. A portable inhalation system for personal exposure to ozone. Asplund PT, Ben-Jebria A, Ultman JS. Department of Chemical Engineering, Pennsylvania State University, University Park, USA. A low-cost portable inhalation system was developed for exposing an individual subject to 60-600 parts per billion of ozone in a 30-l clear-plastic head dome. The inhalation system had the following novel features: a canister vacuum cleaner that supplied room air without the need for precleaning or humidification; a 7% oxygen-in-nitrogen feed to a commercial ultraviolet ozonator that avoided an excess production of ozone; a compact inline mixer that assured homogeneous mixing of the 200-300 liters per minute room air supply with the 0.5-1.0 liters per minute of ozonated gas flow, positioning of gas inlet and exhaust hoses on the head dome that provided fresh gas delivery in the vicinity of the mouth; a quick-disconnect neck seal that allowed rapid donning of the head dome by the subject, and mounting of most system components on a small mobile cart. Temperature, humidity, and ozone and carbon dioxide concentrations were measured inside the dome while a subject exercised on a bicycle ergometer. An air flow of 200 liters per minute between rest and light exercise created a suitable microenvironment in the dome. During moderate and heavy exercise, however, a higher flow of 300 liters per minute should be used to suppress the build-up of carbon dioxide and humidity. PMID: 8638965 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 16: Med Sci Sports Exerc. 1995 Sep;27(9):1333-8. Evaluation of the Cosmed K2 telemetry system during exercise at moderate altitude. Bigard AX, Guezennec CY. Departement de Physiologie Systemique, Centre d'Etudes et de Recherches de Medecine Aerospatiale, Bretigny sur Orge, France. The aim of this study was to test the linearity, precision, and accuracy of the measurements made by the K2 system at sea level (SL) and moderate altitude (MA) (barometric pressure = 591.5 +/- 0.5 mm Hg). To minimize the day-to-day biovariability, a testing protocol based on repeated-alternated measures was used at rest and during three levels of submaximal exercice lasting 12 min each, at 25%, 50%, 75% of the peak workload. The measurements of the respiratory parameters were compared with those obtained with a metabolic measurement cart. The results reported in this study show that the K2 system was an accurate and consistent system for oxygen uptake (VO2) measurements at SL. The K2 system was consistent at MA; however, the K2 system significantly overestimated and underestimated the VO2 computations at rest and 25% of the peak workload, respectively. The calculation of VO2 using the K2 system which assumes that RER = 1.00 had specific effects for the calculation of oxygen uptake. The measurements of FEO2 selectively differed from those obtained with the metabolic measurement cart at MA. Therefore, we concluded that the K2 system was an accurate system for VO2 measurements during submaximal exercices (50%-75% of the peak workload) under laboratory conditions at MA (up to 2,000 m). PMID: 8531634 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 17: J Appl Physiol. 1995 Jun;78(6):2228-34. Comment in: J Appl Physiol. 1996 Mar;80(3):1070-2. Oxygen effect on O2 deficit and VO2 kinetics during exercise in obstructive pulmonary disease. Palange P, Galassetti P, Mannix ET, Farber MO, Manfredi F, Serra P, Carlone S. II Patologia Medica, La Sapienza University Medical School, Rome, Italy. We evaluated the effect of supplemental O2 on energy metabolism of hypoxemic humans by measuring O2 uptake (VO2) kinetics and other cardiorespiratory parameters in nine male chronic obstructive pulmonary disease (COPD) patients and seven age-matched control subjects (on air and on 30% O2) at rest and during moderate cycle ergometer exercise. Heart rate, ventilation, VO2, CO2 output, respiratory exchange ratio, O2 cost of work, and work efficiency were measured with a computerized metabolic cart; O2 deficit and VO2 time courses were calculated. In COPD patients, 30% O2 breathing resulted in 1) reduction of O2 deficit (from 488 +/- 34 ml in air to 398 +/- 27 ml in O2; P < 0.05) and phase 2 VO2 time constant (from 116 +/- 13 s in air to 74 +/- 12 s in O2; P < 0.05); 2) a smaller steady-state increment in CO2 output than in room air (315 +/- 17 ml/min in O2 vs. 358 +/- 27 ml/min in air; P < 0.02), which resulted in a lower exercise respiratory exchange ratio (0.75 +/- 0.02 in O2 vs. 0.80 +/- 0.02 in air; P < 0.02); and 3) reduced steady-state ventilation (22.6 +/- 1.0 l/min in O2 vs. 25.4 +/- 1.1 l/min in air; P < 0.05). In conclusion, 30% O2 breathing accelerated exercise VO2 kinetics in mildly hypoxemic COPD patients. The observed VO2 kinetics improvement with O2 supplementation is consistent with an enhancement of aerobic metabolism in skeletal muscles during moderate exercise. PMID: 7665422 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 18: Am J Cardiol. 1995 Mar 1;75(7):482-4. Effects of atenolol on rest and exercise hemodynamics in patients with mitral stenosis. Stoll BC, Ashcom TL, Johns JP, Johnson JE, Rubal BJ. Department of Medicine, Brooke Army Medical Center, Fort Sam Houston, Texas 78234-6262. Beta-blocker therapy remains controversial in patients with mitral stenosis. In this randomized, double-blind, crossover, placebo-controlled study, the effects of atenolol (50 and 100 mg/day) were assessed in 15 patients (aged 46 +/- 11 years) with mitral stenosis (mean valve area 1.0 +/- 0.4 cm2; New York Heart Association class II or III) at rest and during upright bicycle ergometry. Doppler echocardiography was used to compare heart rate, cardiac and stroke volume indexes, diastolic filling period, and peak and mean transmitral gradients; a metabolic cart was used to obtain maximal oxygen consumption, carbon dioxide production, and anaerobic threshold. Beta-blocking therapy did not improve exercise time, external work, maximal oxygen consumption rate, or anaerobic threshold. Compared with placebo, maximal oxygen consumption rate and cardiac index decreased (p < 0.05) > 11% and > 20%, respectively, with atenolol at peak exercise. Although heart rate was reduced > 20% and diastolic filling period prolonged > 40% by atenolol at rest and exercise (p < 0.05), stroke volume index changed little compared with placebo. The data suggest that despite lower transvalvular pressure gradients, little benefit in exercise performance is achieved with beta-blocker therapy in patients with severe mitral stenosis. Publication Types: Clinical Trial Randomized Controlled Trial PMID: 7863993 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 19: Eur J Appl Physiol Occup Physiol. 1995;70(5):462-7. Validity of a new portable indirect calorimeter: the AeroSport TEEM 100. Novitsky S, Segal KR, Chatr-Aryamontri B, Guvakov D, Katch VL. Department of Movement Science, School of Medicine, University of Michigan, Ann Arbor 48109-2214, USA. The purpose of this study was to compare oxygen uptake (VO2) values collected with a new portable indirect calorimeter (AeroSport TEEM 100 Metabolic Analysis System) against a more traditional large calorimeter system that has been reported to be valid and reliable (SensorMedics 2900 Metabolic Measurement Cart). Minute ventilations ranging from rest up to heavy exercise were compared with simultaneous measurements from a 120-1 Tissot gasometer. Each of the three TEEM 100 pneumotachs were tested. Three hundred and sixty-one separate ventilation tests were performed using the low-flow, medium-flow, and high-flow heads of the portable calorimeter. For each of the pneumotachs, the correlation between the portable calorimeter values and the gasometer values exceeded r = 0.94. The standard error of estimate for the low-medium- and high-flow pneumotach were 5.96, 4.89 and 9.0%, respectively, expressed relative to the mean gasometer value. Simultaneous measurements of VO2 using the portable calorimeter and the SensorMedics 2900 unit were compared during rest and at work rates starting at zero watts, increasing by 25 W to 150 W. Each work rate was of 4 min duration. The average of data from minutes 3 and 4 were used in all analyses. There was very close agreement between the two metabolic measurement systems. Except at the 100-W work rate, where the VO2 difference was small (3.9%), yet statistically significant, all of the other differences in VO2 were small and non-significant. The scatter plot of VO2 for the SensorMedics versus the portable Aero-Sport calorimeter revealed close agreement; the correlation was r = 0.96, (SEE = 3.95%).(ABSTRACT TRUNCATED AT 250 WORDS) Publication Types: Clinical Trial PMID: 7671883 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 20: Am J Chin Med. 1995;23(1):37-41. The effect of massage on oxygen consumption at rest. Boone T, Cooper R. Department of Exercise Physiology, College of St. Scholastica, Duluth, MN 55811, USA. This study determined the effect of massage on oxygen consumption at rest. Ten healthy, adult males (mean age = 28 years) volunteered to serve as subjects. During the Control Session, each subject was placed in the supine position on a massage table to remain motionless for 30 minutes. During the Treatment Session, each subject received a 30-minute sports massage of the lower extremities. Oxygen consumption was determined via the Beckman Metabolic Measurement Cart, which was upgraded to estimate cardiac output using the CO2 rebreathing (equilibrium) method. Paired t-tests were used for all tests of statistical significance. There was no significant difference in the subjects' oxygen consumption with the massage. Also, there were no significant differences in heart rate, stroke volume, cardiac output, and arteriovenous oxygen difference during the massage. These findings indicate (1) that massaging the lower extremities results in neither an increase nor a decrease in the subjects' expenditure of energy at rest and (2) that the energy cost of metabolism at rest is determined by the same central and/or peripheral adjustments. PMID: 7598090 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 21: Arch Phys Med Rehabil. 1993 Sep;74(9):965-8. The relationship between total body potassium and resting energy expenditure in individuals with paraplegia. Spungen AM, Bauman WA, Wang J, Pierson RN Jr. Spinal Cord Damage Research Center, Mount Sinai Medical Center, New York, NY. Body composition changes occur with spinal cord injury (SCI): fat-free mass (FFM) decreases and fat mass (FM) increases. FFM has been reported to correlate with resting energy expenditure (REE) in non-SCI individuals. This report addresses the question as to whether REE correlates with measures of FFM in individuals with paraplegia. Twelve males with chronic paraplegia had measurements of total body potassium (TBK), an indicator of lean tissue, by whole body 40K counting, and FFM by dual photon x-ray absorptiometry (FFMDPX). REE was measured using a metabolic cart for exhaled gas analysis. Corrleations between REE and TBK, and REE and FFMDPX were determined. The mean TBK for the group was 2,850 +/- 190 mEq. In all subjects, TBK was below that of expected (predicted from age, height, and weight). For the group this was 34 +/- 0.04% below predicted. The mean FFMDPX was 58.3 +/- 3.3 kg. Following an overnight fast, REE was measured for each subject while in a seated position. The mean REE was 1,855 +/- 70 kcal/day. REE correlates well with both TBK (r = 0.86, p < 0.0005) and FFMDPX (r = 0.80, p < 0.005). In summary, despite losses in metabolically active tissue in individuals with chronic paraplegia, TBK and FFMDPX continue to have a strong relationship with REE. REE (kcal/d) may be used as an indicator of TBK or FFMDPX using the following linear regression equations: TBK (mEq) = 2.28.REE (kcal/d) - 1,377 (SEE = +/- 347) or FFMDPX (kg) = 0.038.REE (kcal/d) - 11.5 (SEE = +/- 7).(ABSTRACT TRUNCATED AT 250 WORDS) PMID: 8379844 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 22: Med Sci Sports Exerc. 1993 Mar;25(3):396-400. Oxygen consumption using the K2 telemetry system and a metabolic cart. Peel C, Utsey C. Department of Physical Therapy, School of Allied Health Sciences, University of Texas Medical Branch, Galveston 77550. The purpose of this study was to compare measurements of oxygen consumption (VO2), ventilation (VE), and respiratory rate (RR) between a relatively new portable, telemetry system (K2) and a system that has been shown to be valid and reliable. Duplicate measurements were made at rest and during four levels of exercise in 10 subjects. Heart rate values were comparable for exercise at the same work level during gas collection using the two systems, indicating that the metabolic stresses were similar. Oxygen consumption measurements were significantly lower using the K2 system compared with a metabolic measurement cart (MMC). There was no significant difference in VE, but RR was lower for measurements made with the MMC. Compared with the MMC, the K2 system uses a slightly different formula to calculate VO2 because the content of carbon dioxide in expired air is not measured. To determine differences resulting from the method of calculating VO2, MMC measurements were applied to the formula used by the K2 system, and K2 values were adjusted using the RER values obtained from the MMC. There were no differences between these calculated values and the values obtained directly from either the MMC or the K2 system. Consequently, we concluded that the lower VO2 values obtained with the K2 system were attributed to the method of collecting and analyzing expired air, rather than to the method of calculating VO2. PMID: 8455457 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 23: Am J Cardiol. 1991 May 15;67(13):1079-83. Left and right ventricular systolic function and exercise capacity with coronary artery disease. Morrison DA, Stovall JR, Barbiere C. Department of Internal Medicine (Cardiology), Denver Veterans Administration Medical Center, Colorado 80220. This prospective study of symptom-limited supine ergometry was conducted to determine the contributions of right ventricular (RV) and left ventricular (LV) systolic function to the exercise capacity of a cohort of patients with coronary artery disease (CAD). Patients with unstable angina, angiographically proven CAD (n = 53) and stable symptoms after medical therapy or angioplasty were included. Documented myocardial infarction (greater than or equal to 2 weeks before exercise) was present in 43 of 53 patients. Angina was the limiting symptom in 11 of 53; the other 42 stopped exercise with dyspnea or fatigue, or both. Oxygen consumption was measured on-line during exercise with a metabolic cart. RV ejection fraction and LV ejection fraction were measured by validated methods from gated blood pool radionuclide ventriculography. There were weak but statistically significant correlations between exercise oxygen consumption and exercise RV ejection fraction (r = 0.30, p less than 0.05) and between exercise oxygen consumption and exercise LV ejection fraction (r = 0.38, p less than 0.01). Multivariate regression analysis, including exercise RV ejection fraction, exercise LV ejection fraction and exercise heart rate versus exercise oxygen consumption revealed a better relation (r = 0.48, p less than 0.005) than any variable in univariate regression. The values of RV and LV ejection fraction at rest did not correlate significantly (r = 0.2, difference not significant), but the exercise values did correlate weakly (r = 0.41, p less than 0.01). The reserve of LV ejection fraction, defined as exercise minus rest value, correlated weakly with exercise oxygen consumption (r = 0.32, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS) PMID: 2024597 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 24: Crit Care Med. 1990 Jun;18(6):657-61. Predictive equation for assessing energy expenditure in mechanically ventilated critically ill patients. Swinamer DL, Grace MG, Hamilton SM, Jones RL, Roberts P, King EG. Division of Critical Care Medicine, University of Alberta, Edmonton, Canada. Traditional formulas, such as the Harris and Benedict equation (HBE), do not accurately predict energy expenditure (EE) in mechanically ventilated, critically ill patients (MVCIP). The purpose of this study was to develop a predictive EE equation to assess EE requirements in MVCIP. A portable metabolic cart was used to measure indirectly EE in 112 MVCIP. Patients were studied at rest and for 30 min on the first or second day of ICU admission. No nutrition was received during the study period. Variables investigated were: age, BSA, Acute Physiology and Chronic Health Evaluation (APACHE II) score, sepsis score, Injury Severity Score (ISS), respiratory rate (f), tidal volume (VT), minute ventilation, mean arterial pressure, heart rate, body temperature (Temp), and outcome. Patient age, APACHE II score, sepsis score, ISS, and BSA were 50 +/- 20 yr, 16 +/- 7, 11 +/- 6, 32 +/- 14, and 1.80 +/- 0.27 m2, respectively. Correlation and multiple regression analyses were used with EE as the dependent variable. A predictive equation (EE [kcal/day] = 945 BSA -6.4 age + 108 Temp + 24.2 f + 817 VT -4349) was determined from variables that contributed greater than 3% to the variance of EE: BSA (52%), age (10%), f (5%), VT (5%), and Temp (3%). The HBE underestimated measured EE by 34 +/- 19% and in 79 patients deviated greater than 15%. Using the new equation, only 15 patients' EE deviated greater than 15% from measured EE. The new predictive EE equation can accurately assess EE in MVCIP. PMID: 2344758 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 25: J Pediatr Surg. 1989 Aug;24(8):825-7; discussion 827-8. Resting energy expenditure in children following major operative procedures. Groner JI, Brown MF, Stallings VA, Ziegler MM, O'Neill JA Jr. Department of Surgery, Children's Hospital of Philadelphia, PA 19104. Resting energy expenditure (REE) is reported to increase by 24% in adults following elective operations; however, similar data are not available for children. We studied REE in 12 children (14 operative procedures) to test the hypothesis that children experience a similar rise in REE as adults following operation. The operations included endorectal pull-through, gastric resection, ileostomy closure, and other major abdominal procedures. REE was measured daily by indirect calorimetry using a computerized bedside metabolic cart. All subjects (7 males, 5 females; age range, 8 to 19 years; mean age, 14.7 years) were measured supine, in bed, and after an overnight fast. REE was expressed as kilocalories per unit body surface area (BSA) per day. In addition, respiratory quotient (RQ) was calculated for each patient. Contrary to adults, these children did not demonstrate a significant increase in REE following major operative procedures. Furthermore, there was no change in RQ postoperatively. These data demonstrate that children might have a different response to surgical stress than adults. We theorize that children are able to convert energy expended on growth to energy spent on wound repair and healing, thus avoiding the overall increase in energy expenditure seen in the adult population. PMID: 2769551 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 26: Aviat Space Environ Med. 1988 Dec;59(12):1150-7. Prediction of physical workload in reduced gravity. Goldberg JH, Alred JW. Pennsylvania State University, University Park. As we plan for long-term living and working in low-gravity environments, a system to predict mission support requirements, such as food and water, becomes critical. Such a system must consider the workload imposed by physical tasks for efficient estimation of these supplies. An accurate estimate of human energy expenditure on a space station or lunar base is also necessary to allocate personnel to tasks, and to assign work-rest schedules. An elemental analysis approach for predicting one's energy expenditure in industrial jobs was applied to low-gravity conditions in this paper. This was achieved by a reduction of input body and load weights in a well-accepted model, in proportion to lowered gravity, such as on the moon. Validation was achieved by applying the model to Apollo-era energy expenditure data. These data were from simulated lunar gravity walking studies, observed Apollo 14 walking, simulated lunar gravity upper body torquing, and simulated lunar gravity cart pulling. The energy expenditure model generally underpredicted high energy expenditures, and overpredicted low to medium energy expenditures. The predictions for low to medium workloads were, however, within 15-30% of actual values. Future developmental work will be necessary to include the effects of traction changes, as well as other nonlinear expenditure changes in reduced gravity environments. PMID: 3240215 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 27: Arch Phys Med Rehabil. 1988 Jul;69(7):548-51. Interface design for indirect calorimetry in children with cerebral palsy. McClenaghan B, Hill S, Koheil R, Okazaki C. Motor Rehabilitation Laboratory, University of South Carolina, Columbia 29208. The purpose of this study was to design, construct, and validate an alternative subject/instrument interface to collect metabolic data for individuals who, because of impairment, are unable to use a mouthpiece. An industrial designer directed the development of an interface design which would facilitate subject acceptance. A total of 13 subjects (eight children with cerebral palsy and five nonneurologically impaired) participated in the validation study. Metabolic data were collected at rest and during three levels of exercise, using both the traditional mouthpiece and the interface designed for this study. Exercise intensities were matched for both experimental conditions. Subjects exercised using an electrically braked ergometer configured for arm pedaling. A modification in a Beckman Metabolic Cart allowed for the collection of values with a standard mouthpiece and low-flow interface. Validity of the interface was evaluated using a concurrent, criterion procedure. Correlations of mouthpiece vs interface data during rest and across each exercise level for oxygen consumption were high (r = 0.94 to 0.84; p less than 0.05). Similar results were obtained for carbon dioxide production (r = 0.92 to 0.85; p less than 0.05). PMID: 3389998 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 28: Eur J Appl Physiol Occup Physiol. 1985;54(1):104-8. The relationship between lactate and ventilatory thresholds: coincidental or cause and effect? Neary PJ, MacDougall JD, Bachus R, Wenger HA. To determine if blood lactate (LA) is the stimulus responsible for 'breakaway' ventilation (VE), the lactate (LT) and ventilation (VT) thresholds were monitored during one-legged cycling exercise. Ten healthy volunteer male subjects (Mean 2-legged VO2max = 4.27 l X min-1) performed prior exercise (PE) to reduce muscle glycogen stores by cycling at 75-85% of maximal heart rate (HR max) for 60-75 min, followed by a 30 h low carbohydrate diet. Pre- and post- LT and VT tests were performed on a cycle ergometer employing a continuous protocol with increments of 16 W every 3 min. Muscle biopsies were taken from the vastus lateralis muscle before the PE ride, prior to the threshold test 24 h later, and before testing the non-exercised (NE) leg. An I.V. catheter placed in the antecubital vein was used for serial blood samples taken at rest, and during the final 30 s of each progressive load. Gas analysis was calculated every 30 s (Beckman Metabolic Measurement Cart). Biopsies (N = 3) showed that the exercise and diet regimen elicited glycogen reduction which significantly (p less than 0.05) reduced R and the blood LA concentration in both the PE (2.62 to 1.99 mmol X l-1) and NE (2.87 to 2.26 mmol X l-1) legs at LT. At VT, LA concentrations were also significantly reduced in the PE (3.35 to 2.56 mmol X l-1) and NE (3.59 to 2.74 mmol X l-1) legs. VO2 and VE, however, were similar between pre- and post- tests.(ABSTRACT TRUNCATED AT 250 WORDS) PMID: 4018043 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 29: J Appl Physiol. 1983 Apr;54(4):1083-8. Effect of exercise on QRS duration in healthy men: a computer ECG analysis. Goldberger AL, Bhargava V. Increased sympathetic tone with exercise enhances ventricular conduction and would be predicted to shorten QRS duration. Previous studies, however, have not consistently documented such changes. Using a digital electrocardiograph (ECG) cart sampling at 500 Hz, a bipolar precordial lead (V5-V2) was recorded (supine, at end expiration) in 25 healthy men (mean age 29 yr, range 19-37) at rest and immediately after submaximal treadmill exercise. QRS duration was measured on complexes recorded at high gain and expanded time scale. A significant (P less than 0.0005) decrease [4.9 +/- 2.3 (SD) ms] in QRS duration was noted, and decreased QRS duration was observed in all 25 subjects (range 1-10 ms). Furthermore there was significant (P less than 0.01) shortening of the intervals between QRS onset and Q-wave nadir (1.2 +/- 2.0 ms) and between QRS onset and R-wave peak (2.4 +/- 2.5 ms), as well as of the Q-R interval (1.3 +/- 2.7 ms). However, there were no significant differences in percent shortening of early vs. later phases of the QRS. To exclude digital sampling errors the same protocol was also applied in 11 healthy men by using an analog ECG cart. QRS duration immediately postexercise shortened by 7.1 +/- 4.3 ms (range 2-11.5 ms), which was not significantly different from the results obtained with the digital ECG. We conclude that decreased QRS duration is a physiological response to moderate treadmill exercise in healthy men, reflecting enhancement of conduction in early, middle, and later phases of ventricular activation. PMID: 6853284 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 30: Am J Physiol. 1982 Dec;243(6):H964-9. Effect of exercise in healthy men on QRS power spectrum. Bhargava V, Goldberger AL. The effect of exercise on the QRS power spectrum has not been evaluated. We hypothesized that increased conduction velocity with exercise might selectively increase high-frequency QRS potentials. Using a digital electrocardiograph (ECG) cart, a single bipolar chest lead was recorded in 21 healthy adult males at rest and then immediately after treadmill exercise. Fast Fourier transform analysis of the ECGs was performed using a 128-ms sampling window, including the QRS but not the P wave. Step discontinuities between PR and ST segments were minimized using a linear correction function to obviate artifactual increases in high-frequency content after exercise. The power spectrum plots of rest and exercise data showed an increase in the amplitude of high frequencies that could not be accounted for on the basis of noise contamination. For the frequency band between 187.5 and 250 Hz, the root-mean-square (RSM) voltage of exercise QRS complexes (10.0 +/- 3.6 micro V) was significantly (P less than 0.02) greater than that of rest QRS complexes (7.8 +/- 1.2). However, base-line noise level (computed over a 32-ms interval during the ST segment) was not different between rest and exercise over this high-frequency band. The same exercise protocol was also applied in 11 normal male subjects using an analog ECG cart. For the 187.5- to 250-Hz band, the RMS voltage of the QRS after exercise (13.0 +/- 1.8 micro V) was also significantly (P less than 0.01) greater than at rest (10.2 +/- 2.8) without any difference in ST segment noise level over the same frequency range. These data indicate that exercise causes an increase in the amplitude of high-frequency QRS potentials in healthy men. PMID: 7149049 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 31: J Appl Physiol. 1982 Jun;52(6):1493-7. An automated, indirect assessment of cardiac output during rest and exercise. Wilmore JH, Farrell PA, Norton AC, Cote RW 3rd, Coyle EF, Ewy GA, Temkin LP, Billing JE. The present study describes a modification of the equilibration CO2-rebreathing technique for determining cardiac output (Q), utilizing the Beckman Metabolic Measurement Cart (MMC) to provide partial automation of the procedures described by Jones et al. (Clinical Exercise Testing. Philadelphia, PA: Saunders, 1975). Q was determined in six normal healthy males to establish the reliability of the technique at rest, and during exercise at power outputs of 49 and 98 W, or 300 and 600 kpm/min. An additional 11 patients, who were symptomatic for coronary artery disease and scheduled for right and left heart catheterization, were used in validating these procedures against Q determined by the thermodilution method. The automated CO2-rebreathing procedure was found to be reliable at rest and during exercise, and demonstrated a direct linear relationship with VO2 (r = 0.90). Also, this procedure correlated (r = 0.87) with the thermodilution method during supine rest, and both methods were quite consistent between trials within the same subject. It was concluded that the CO2-rebreathing procedure used in this study, as interfaced with the Beckman MMC, provides reasonable estimates of Q, both in patients during supine rest, and in normal healthy subjects at rest and during low to moderate levels of exercise. PMID: 7107459 [PubMed - indexed for MEDLINE] ---------------------------------------------------------------