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Notley SR, Mitchell D, Taylor NAS. A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 3: Heat and cold tolerance during exercise. Eur J Appl Physiol 2024; 124:1-145. [PMID: 37796292 DOI: 10.1007/s00421-023-05276-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 07/04/2023] [Indexed: 10/06/2023]
Abstract
In this third installment of our four-part historical series, we evaluate contributions that shaped our understanding of heat and cold stress during occupational and athletic pursuits. Our first topic concerns how we tolerate, and sometimes fail to tolerate, exercise-heat stress. By 1900, physical activity with clothing- and climate-induced evaporative impediments led to an extraordinarily high incidence of heat stroke within the military. Fortunately, deep-body temperatures > 40 °C were not always fatal. Thirty years later, water immersion and patient treatments mimicking sweat evaporation were found to be effective, with the adage of cool first, transport later being adopted. We gradually acquired an understanding of thermoeffector function during heat storage, and learned about challenges to other regulatory mechanisms. In our second topic, we explore cold tolerance and intolerance. By the 1930s, hypothermia was known to reduce cutaneous circulation, particularly at the extremities, conserving body heat. Cold-induced vasodilatation hindered heat conservation, but it was protective. Increased metabolic heat production followed, driven by shivering and non-shivering thermogenesis, even during exercise and work. Physical endurance and shivering could both be compromised by hypoglycaemia. Later, treatments for hypothermia and cold injuries were refined, and the thermal after-drop was explained. In our final topic, we critique the numerous indices developed in attempts to numerically rate hot and cold stresses. The criteria for an effective thermal stress index were established by the 1930s. However, few indices satisfied those requirements, either then or now, and the surviving indices, including the unvalidated Wet-Bulb Globe-Thermometer index, do not fully predict thermal strain.
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Affiliation(s)
- Sean R Notley
- Defence Science and Technology Group, Department of Defence, Melbourne, Australia
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Duncan Mitchell
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
- School of Human Sciences, University of Western Australia, Crawley, Australia
| | - Nigel A S Taylor
- Research Institute of Human Ecology, College of Human Ecology, Seoul National University, Seoul, Republic of Korea.
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Notley SR, Mitchell D, Taylor NAS. A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 1: Foundational principles and theories of regulation. Eur J Appl Physiol 2023; 123:2379-2459. [PMID: 37702789 DOI: 10.1007/s00421-023-05272-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 06/30/2023] [Indexed: 09/14/2023]
Abstract
This contribution is the first of a four-part, historical series encompassing foundational principles, mechanistic hypotheses and supported facts concerning human thermoregulation during athletic and occupational pursuits, as understood 100 years ago and now. Herein, the emphasis is upon the physical and physiological principles underlying thermoregulation, the goal of which is thermal homeostasis (homeothermy). As one of many homeostatic processes affected by exercise, thermoregulation shares, and competes for, physiological resources. The impact of that sharing is revealed through the physiological measurements that we take (Part 2), in the physiological responses to the thermal stresses to which we are exposed (Part 3) and in the adaptations that increase our tolerance to those stresses (Part 4). Exercising muscles impose our most-powerful heat stress, and the physiological avenues for redistributing heat, and for balancing heat exchange with the environment, must adhere to the laws of physics. The first principles of internal and external heat exchange were established before 1900, yet their full significance is not always recognised. Those physiological processes are governed by a thermoregulatory centre, which employs feedback and feedforward control, and which functions as far more than a thermostat with a set-point, as once was thought. The hypothalamus, today established firmly as the neural seat of thermoregulation, does not regulate deep-body temperature alone, but an integrated temperature to which thermoreceptors from all over the body contribute, including the skin and probably the muscles. No work factor needs to be invoked to explain how body temperature is stabilised during exercise.
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Affiliation(s)
- Sean R Notley
- Defence Science and Technology Group, Department of Defence, Melbourne, Australia
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Duncan Mitchell
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
- School of Human Sciences, University of Western Australia, Crawley, Australia
| | - Nigel A S Taylor
- Research Institute of Human Ecology, College of Human Ecology, Seoul National University, Seoul, Republic of Korea.
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Abstract
Thoracic surgery represents a special challenge for anesthesia and requires a high level of human and material resources. Accurate knowledge of the pathophysiology is essential for selection of the anesthetic procedure, the separation of the lungs, monitoring and treatment of hemodynamics as well as for postoperative follow-up care. The increasing number of thoracic interventions and patients who are often suffering from complex diseases require close interdisciplinary cooperation between surgeons, anesthesiologists and intensive care specialists. In addition to the anesthetic techniques particular attention must be paid to the prevention of perioperative complications that can have a relevant effect on patient outcome. In particular hypoxemia during one-lung ventilation influences postoperative morbidity and mortality. Protective pulmonary ventilation strategies play an important role in prevention of postoperative acute lung injury.
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Affiliation(s)
- T Kammerer
- Klinik für Anaesthesiologie, Klinikum Großhadern, Ludwig-Maximilians-Universität, Marchioninistr.15, 81377, München, Deutschland.
| | - E Speck
- Klinik für Anaesthesiologie, Klinikum Großhadern, Ludwig-Maximilians-Universität, Marchioninistr.15, 81377, München, Deutschland
| | - V von Dossow
- Klinik für Anaesthesiologie, Klinikum Großhadern, Ludwig-Maximilians-Universität, Marchioninistr.15, 81377, München, Deutschland
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Dautrebande L, Davies HW. A study of the chlorine interchange between corpuscles and plasma. J Physiol 2007; 57:36-46. [PMID: 16993597 PMCID: PMC1405452 DOI: 10.1113/jphysiol.1922.sp002040] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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Redfield AC, Bock AV, Meakins JC. The measurement of the tension of oxygen and carbon dioxide in the blood of the pulmonary artery in man. J Physiol 2007; 57:76-81. [PMID: 16993602 PMCID: PMC1405446 DOI: 10.1113/jphysiol.1922.sp002044] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Barcroft J, Marshall EK. Note on the effect of external temperature on the circulation in man. J Physiol 2007; 58:145-56. [PMID: 16993648 PMCID: PMC1405496 DOI: 10.1113/jphysiol.1923.sp002111] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Lindhard J. Circulation after cessation of work, with some remarks on the calculation of circulation rate experiments according to the nitrous oxide method. J Physiol 2007; 57:17-30. [PMID: 16993595 PMCID: PMC1405447 DOI: 10.1113/jphysiol.1922.sp002038] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Paterson WD. Circulatory and respiratory changes in response to muscular exercise in man. J Physiol 2007; 66:323-45. [PMID: 16993996 PMCID: PMC1402784 DOI: 10.1113/jphysiol.1928.sp002531] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Huggett AS. Studies on the respiration and circulation of the cat: IV. The heart output during respiratory obstruction. J Physiol 2007; 59:373-80. [PMID: 16993720 PMCID: PMC1405802 DOI: 10.1113/jphysiol.1924.sp002193] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Burwell CS, Robinson GC. THE GASEOUS CONTENT OF THE BLOOD AND THE OUTPUT OF THE HEART IN NORMAL RESTING ADULTS. J Clin Invest 2006; 1:87-95. [PMID: 16693643 PMCID: PMC434545 DOI: 10.1172/jci100006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Harrison TR, Wilson CP, Blalock A. THE EFFECTS OF CHANGES IN HYDROGEN ION CONCENTRATION ON THE BLOOD FLOW OF MORPHINIZED DOGS. J Clin Invest 2006; 1:547-68. [PMID: 16693667 PMCID: PMC434569 DOI: 10.1172/jci100030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- T R Harrison
- Department of Medicine of The Johns Hopkins University
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Richards DW, Cournand A, Bryan NA. APPLICABILITY OF REBREATHING METHOD FOR DETERMINING MIXED VENOUS CO(2) IN CASES OF CHRONIC PULMONARY DISEASE. J Clin Invest 2006; 14:173-80. [PMID: 16694288 PMCID: PMC424669 DOI: 10.1172/jci100665] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- D W Richards
- Department of Medicine of the College of Physicians and Surgeons, Columbia University, New York City
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Altschule MD, Volk MC. THE MINUTE VOLUME OUTPUT AND THE WORK OF THE HEART IN HYPOTHYROIDISM. J Clin Invest 2006; 14:385-8. [PMID: 16694311 PMCID: PMC424692 DOI: 10.1172/jci100688] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- M D Altschule
- Department of Medicine, Harvard University Medical School, Boston
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Richards DW, Strauss ML. CARBON DIOXIDE AND OXYGEN TENSIONS OF THE MIXED VENOUS BLOOD OF MAN AT REST. J Clin Invest 2006; 9:475-532. [PMID: 16693947 PMCID: PMC435710 DOI: 10.1172/jci100318] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- D W Richards
- Department of Medicine, Columbia University, New York
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Schindler AW, Scheeren TWL, Picker O, Doehn M, Tarnow J. Accuracy of feedback-controlled oxygen delivery into a closed anaesthesia circuit for measurement of oxygen consumption. Br J Anaesth 2003; 90:281-90. [PMID: 12594137 DOI: 10.1093/bja/aeg072] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Oxygen consumption (V*O2) is rarely measured during anaesthesia, probably because of technical difficulties. Theoretically, oxygen delivery into a closed anaesthesia circuit (V*O2-PF; PhysioFlex Draeger Medical Company, Germany) should measure V*O2. We aimed to measure V*O2-PF in vitro and in vivo. METHODS Three sets of experiments were performed. V*O2-PF was assessed with five values of V*O2 (0-300 ml min(-1)) simulated by a calibrated lung model (V*O2-Model) at five values of FIO2 (0.25-0.85). The time taken for V*O2-PF to respond to changes in V*O2-Model gave a measure of dynamic performance. In six healthy anaesthetized dogs we compared V*O2-PF with V*O2 measured by the Fick method (V*O2-Fick) during ventilation with nine values of FIO2 (0.21-1.00). V*O2-PF and V*O2-Fick were also compared in three dogs when V*O2 was changed pharmacologically [102 (SD 14), 121 (17) and 200 (57) ml min(-1)]. In patients during surgery, we measured V*O2-PF and V*O2-Fick simultaneously after induction of anaesthesia (n=21) and during surgery (n=17) (FIO2 0.3-0.5). RESULTS Compared with V*O2-Model, V*O2-PF values varied from time to time so that averaging over 10 min is recommended. Furthermore, at an FIO2 >0.8, V*O2-PF always overestimated V*O2. With FIO2 <0.8, averaged V*O2-PF corresponded to V*O2-Model and adapted rapidly to changes. Averaged V*O2-PF also corresponded to V*O2-Fick in dogs at FIO2 <0.8. V*O2 measured by the two methods gave similar results when V*O2 was changed pharmacologically. In contrast, V*O2-PF systematically overestimated V*O2-Fick in patients by 52 (SD 40) ml min-1 and this bias increased with smaller arteriovenous differences in oxygen content. CONCLUSION V*O2-PF measures V*O2 adequately within specific conditions.
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Affiliation(s)
- A W Schindler
- Department of Anaesthesiology, University-Hospital Düsseldorf, Moorenstrasse 5, D-40225 Düsseldorf, Germany.
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WANG Y, MARSHALL RJ, SHEPHERD JT. The effect of changes in posture and of graded exercise on stroke volume in man. J Clin Invest 1998; 39:1051-61. [PMID: 13842816 PMCID: PMC441849 DOI: 10.1172/jci104120] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Hicks JW, White FN. Pulmonary gas exchange during intermittent ventilation in the American alligator. RESPIRATION PHYSIOLOGY 1992; 88:23-36. [PMID: 1626141 DOI: 10.1016/0034-5687(92)90026-s] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The present study characterized pulmonary gas exchange in the American alligator, Alligator mississipiensis during ventilation and apnea at a body temperature (Tb) of 25 degrees C. Pulmonary gas exchange parameters were measured on a breath-by-breath basis utilizing a computer-assisted data acquisition system. In addition, paired blood samples were analyzed from left and right atrium during ventilation and voluntary apneas (1, 2, 5 and 10 min). Measurements of lung PO2 and PCO2 indicated that as apnea progressed, CO2 flux into the lung decreased rapidly while O2 was continuously removed at a constant and steady rate. The reduction in VCO2 resulted in a decrease in R (less than 0.4). Blood gas measurements indicated that the pulmonary arterial-pulmonary venous PCO2 difference, (Ppa-Ppv)CO2 was 4.9 +/- 0.9 mmHg during ventilation, decreased and became negative within 2 min of apnea, reaching -3.9 +/- 0.6 mmHg after 10 min. It is postulated that during apnea the Haldane effect accounts for both the blood gas behavior across the lung and insures a continued CO2 flux into the lung during apnea.
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Affiliation(s)
- J W Hicks
- Physiological Research Laboratory, Scripps Institution of Oceanography, University of California, San Diego, La Jolla 92023
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Sturdy S. Biology as social theory: John Scott Haldane and physiological regulation. BRITISH JOURNAL FOR THE HISTORY OF SCIENCE 1988; 21:315-340. [PMID: 11621622 DOI: 10.1017/s0007087400025012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
During the first forty years of this century, the concept of a living organism was discussed widely and publicly by biologists and philosophers. Two questions in particular excited discussion. In what ways should organisms be considered different from or the same as dead matter? And what can we learn about the nature of human society by regarding it as analogous to a living organism? Inevitably, these questions were closely related; the conclusions to be drawn about the social organism would depend upon the particular properties attributed to the biological organism. In more recent years, discussion of these issues has largely been in abeyance, as biologists have with-drawn from debate over social policy into a more remote academia. A few biologists who still see their work as relevant to a wider social agenda have continued to treat the nature of life as a contentious issue. But the focus of interest has shifted away from the organismic analogy, which concerns the organization of society as a whole, to issues like sociobiology and evolutionary theory, which emphasize social differentiation and the treatment of out-groups and minorities.
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Haffor AS, Nail JB. Microprocessor-controlled mixing system for rebreathing equilibration. COMPUTERS AND BIOMEDICAL RESEARCH, AN INTERNATIONAL JOURNAL 1988; 21:101-9. [PMID: 3131062 DOI: 10.1016/0010-4809(88)90018-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A simple, economic, and accurate microprocessor system for the determination of mixed venous PCO2 has been described. Through the automatic gas mixing system, it is possible to facilitate the use of the rebreathing equilibration technique for the purpose of cardiac output calculations. It was also possible to flush the rebreathing bag within a brief time, providing the investigator with an automatic three-way valve driven by a solenoid.
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Affiliation(s)
- A S Haffor
- Health, Physical Education, and Recreation Department, Mississippi State University, Mississippi 39762
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Bureau MA, Bégin R, Berthiaume Y, Shapcott D, Khoury K, Gagnon N. Cerebral hypoxia from bicarbonate infusion in diabetic acidosis. J Pediatr 1980; 96:968-73. [PMID: 6768868 DOI: 10.1016/s0022-3476(80)80619-6] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
To study the delivery of oxygen to the cerebral tissue during metabolic acidosis and its therapy with bicarbonate (NaHCO3), oxygen partial pressure of the cisternal fluid was measured in 12 experiments of HCl-induced acidemia and eight experiments of diabetic ketoacidosis in 16 unanesthetized dogs. Full correction of acidosis with bicarbonate caused a significant (P less than 0.05) decrease in Pcsf 2: in the HCl acidotic dogs, Pcsfo2 decreased from 53.9 +/- 2.2 torr to 45.9 +/- 2.3 torr within one hour; in the ketoacidotic dogs, Pcsfo2 decreased for 48.5 +/- 5.4 torr to 26.7 +/- 6.6 torr within six hours. In the ketoacidotic dogs not treated with bicarbonate, there was no significant change in Pcsfo2. An inverse relationship (P less than 0.01) between the cisternal lactic acid level and the cisternal PO2 was also observed. It is concluded that NaHCO3 therapy in diabetic ketoacidosis decreases the cerebral O2 availability and that cerebral hypoxia contributes to the brain dysfunction encountered after the initiation of such therapy in acidemia.
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Miyamura M, Honda Y. CO2 dissociation curves of oxygenated whole blood obtained at rest and in exercise. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1978; 39:37-45. [PMID: 679942 DOI: 10.1007/bf00429677] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In vitro CO2 dissociation curves for oxygenated whole blood were determined in 19 healthy male subjects at rest and during submaximal and maximal bicycle work. Hemoglobin concentration and blood lactate increased with increasing work load and accordingly buffer value of the whole blood increased while bicarbonate and Base Excess (BE) decreased, resulting in a downward shift of the CO2 dissociation curve during exercise. Despite the marked increase in buffer values of the blood, the slopes of the CO2 dissociation curves during exercise were found to be about the same as those obtained at rest. It was inferred that the increasing effect of increased buffer value, on the dissociation slope, was essentially compensated by the decreasing effect of diminished bicarbonate content. The advantages of this relatively constant CO2 dissociation slope for the indirect measurement of cardiac output by the Fick principle are discussed.
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Abstract
The CO2 rebreathing cardiac output method is a totally noninvasive Fick procedure needing validation in various disease states to become clinically applicable. Simultaneous measurements of cardiac output by CO2 rebreathing and dye-dilution or direct Fick techniques were performed in 53 patients. In nine patients with pulmonary disease rebreathing cardiac output averaged 4.85 L/min compared to 5.18 L/min by dye-dilution or Fick (r = 0.16). In 14 instances of acute myocardial infarction cardiac output was 5.53 L/min by rebreathing and 5.87 L/min by dye-dilution (r = 0.95), while in nine shock cases it averaged 3.98 L/min by dye-dilution or Fick and 3.75 L/min by CO2 rebreathing (r = 0.94). In five heart failure cases with mitral insufficiency, which may distort dye durves, correlation between standard and rebreathing methods was r = 0.09, but in 16 cases without mitral regurgitation, r = 0.89. Acute interventions in ten patients increased dye-dilution cardiac output by 0.92 L/min and rebreathing outputs by 0.60 L/min (r = 0.87). The data suggest that the CO2 rebreathing cardiac output method may be useful in the CCU-MICU setting.
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Bailey IK, Anderson SD, Rozea PJ, Bernstein L, Nyberg G, Korner PI. Effect of beta-adrenergic blockade with alprenolol on ST-segment depression and circulatory dynamics during exercise in patients with effort angina. Am Heart J 1976; 92:416-26. [PMID: 961582 DOI: 10.1016/s0002-8703(76)80040-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
1. Nine subjects with severe coronary artery disease were studied during graded "sprint" and "steady-state" exercise before and after intravenous administration of the beta-receptor antagonist alprenolol. During "sprint" workload was increased every minute until maximum work capacity (Wmax) was reached. "Steady-state" exercise was performed at work rates of 0.250, 0.50, and 0.75 of each subject's sprint Wmax. Variables measured included ST-segment depression, changes in heart rate, blood pressure, respiratory gas exchange, and arterial blood composition. Cardiac output (indirect Fick) was measured during "steady-state" exercise. 2. Alprenolol did not alter Wmax during "sprint" but reduced the incidence of angina in both types of exercise. After the drug work capacity was limited by symptoms and signs suggestive of mild left ventricular failure. 3. The relationship between workload (normalized in terms of Wmax) and ST-segment depression was curvilinear. Under control conditions a given rate of work during "steady-state" exercise was assocaited with more marked ST-segment depression than during "sprint". Alprenolol displaced the work-ST-depression curve to the right in each type of exercise; now a given rate of work produced similar ST-depressing during "steady-state" and "sprint" exercise. 4. Alprenolol attentuated the exercise tachycardia during both types of exercise. Cardiac output was lower in "steady-state" exercise after the drug than under control conditions. Metabolic effects included significant reduction in body oxygen consumption after alpreprenolol at 0.25 Wmax and diminished arterial lactate at 0.75 Wmax. The beneficial effects of the drug thus appeared to involve not only cardiac but peripheral effects on beta receptors. 5. Before alprenolol cardiac output was relatively fixed at all workloads, but after the drug there was a work-related rise in output in five out of nine subjects. Comparison with data in normal subjects suggested that in anginal subjects cardiac output at low "steady-state" workloads was inappropriately high.
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Brindley GS. The variability of the human striate cortex. J Physiol 1972; 225:1P-3P. [PMID: 5074382 PMCID: PMC1331010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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Godfrey S, Katzenelson R, Wolf E. Gas to blood PCO 2 differences during rebreathing in children and adults. RESPIRATION PHYSIOLOGY 1971; 13:274-82. [PMID: 5158846 DOI: 10.1016/0034-5687(71)90032-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Stegemann J, Kenner T. A theory on heart rate control by muscular metabolic receptors. ARCHIV FUR KREISLAUFFORSCHUNG 1971; 64:185-214. [PMID: 4326021 DOI: 10.1007/bf02120466] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Döhring W, Thews G. [An extrapolation method for the bloodless determination of the O2 and CO2 partial pressure in mixed venous blood]. Pflugers Arch 1969; 311:326-41. [PMID: 5388310 DOI: 10.1007/bf00587228] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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JERNERUS R, LUNDIN G, THOMSON D. Cardiac Output in Healthy Subjects Determined with a CO2Rebreathing Method. ACTA ACUST UNITED AC 1963; 59:390-9. [PMID: 14082610 DOI: 10.1111/j.1748-1716.1963.tb02755.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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STEGEMANN J. [On the mechanism of pulse frequency regulation by metabolism. I. The influence of metabolism in a muscle group isolated from the circulation on the behavior of the pulse frequency]. PFLUGERS ARCHIV FUR DIE GESAMTE PHYSIOLOGIE DES MENSCHEN UND DER TIERE 1963; 276:481-92. [PMID: 13983630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/24/2023]
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BEVEGARD S, HOLMGREN A, JONSSON B. Circulatory Studies in Well Trained Athletes at Rest and During Heavy Exercise, with Special Reference to Stroke Volume and the Influence of Body Position. ACTA ACUST UNITED AC 1963; 57:26-50. [PMID: 13967908 DOI: 10.1111/j.1748-1716.1963.tb02572.x] [Citation(s) in RCA: 153] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Donal JS. A CONVENIENT METHOD FOR THE DETERMINATION OF THE APPROXIMATE CARDIAC OUTPUT IN MAN. J Clin Invest 1937; 16:879-87. [PMID: 16694534 PMCID: PMC424927 DOI: 10.1172/jci100914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- J S Donal
- Laboratory of Pharmacology of the University of Pennsylvania, Philadelphia
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Rabinowitch IM. PREDICTION OF BASAL METABOLISM FROM PULSE PRESSURE AND PULSE RATE. CANADIAN MEDICAL ASSOCIATION JOURNAL 1935; 32:135-142. [PMID: 20319780 PMCID: PMC1560997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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