DOCSLIB.ORG

DECOMPRESSION EMERGENCIES 1I in PRESSURE-SUITED SUBJECTS I I'; by Emanuel M

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
DECOMPRESSION EMERGENCIES 1I in PRESSURE-SUITED SUBJECTS I I'; by Emanuel M I https://ntrs.nasa.gov/search.jsp?R=19690004637". 2020-03-23T22:37:56+00:00Z LOAN CQPY: RETURN TO AFWt (WLIL-2) KIRTLAND AFB, ME>( t- N $- j !:> I$& -, RAPID (EXPLOSIVE) pP1 DECOMPRESSION EMERGENCIES 1i IN PRESSURE-SUITED SUBJECTS i I'; by Emanuel M. Rotb i ' Prepared by THE LOVELACE FOUNDATION I Albuquerque, N. Mex. ! for j NATIONALAERONAUTICS AND SPACE ADMINISTRATION WASHINGTON,D. C. NOVEMBER 1968 w TECH LIBRARY KAFB, NM OOb031& NASA CR-1223 RAPID (EXPLOSIVE) DECOMPRESSION EMERGENCIES IN PRESSURE-SUITED SUBJECTS By Emanuel M. Roth, M.D. Distribution of this report is provided in the interest of informationexchange. Responsibility for the contents resides in the author or organization that prepared it. Prepared under Contract No. NASr- 115 by THE LOVELACE FOUNDATION FOR MEDICAL EDUCATION AND RESEARCH Albuquerque, N. Mex. for NATIONAL AERONAUTICS AND SPACE ADMINISTRATION For sale by the Clearinghouse for Federal Scientific and Technical Information Springfield, Virginia 22151 - CFSTI price $3.00 FOREWORD This study of explosive decompression emergencies in vacuum test chambers was performed upon request of Dr. E. L. Beckman, Acting Chief, Preventive Medicine Office, Manned Spacecraft Center, Houston, Texas, and submitted through the Directorate of Space Medicine, Headquarters Office of MSF, NASA. I wish to acknowledge the aid given by Dr. William V. H. Mason, Dr. UlrichLuft, Dr. Archer S. Gordon,Mr. Gerald Bowen, Dr. Royce Fletcher,and Mr. Ronald'Rietz of the Lovelace Foundation and Dr. Rodger E. MacQuigg of the Lovelace Clinic through their critical review of the manuscript and suggestions made in analysis of the problem. Many of the data used in evaluation of current space suits were obtained by verbal communication with several different groups. The individuals who contributed to this analysis were Messrs. Edward Michel, JosephKosmo, M. I. Radnofsky, C.C. Lutz,and J. H. Chappee of the Manned Spacecraft Center, Houston and Mr. Pierre Brousseau of the Space Sciences Laboratories, Litton Industries. Any errors of omission or commission are the fault of the author in misinterpreting these un- published data. Thanks are also due Drs. Richard Bancroft and Fritz Holmstrom of the USAF, SAM, Brooks AFB for Air Force data and Dr. Karl Schaefer of the U. S. Naval Research Laboratory, New London, and Captain R. D. Workman of theNMRI, Washington, D. C., for their interpretation of U. S. Navy diving experience. I also wish to gratefully acknowledge the task performed by Miss Dorothy Tyson, Mrs. Irene Brian, Mrs. Marjorie Wilson, and the members of the Document Library of the Lovelace Foundation in the preparation of this report. iii TABLE OF CONTENTS I . Physical Considerations in Damage to the Lung During ExplosiveDecompression ............ 1 I1 . Evaluation of Decompression Hazards Following Specific Suit Failures .............. 17 A . SoftSuit ..................... 18 B . HardSuit ..................... 22 C . Time of Decompressionand Hazard Analysis ... 25 I11 . Pathological Phvsiology of Explosive Decompression to a Vacuum .................. 34 Contusionand Disruption of Lung Parenchyma ..... 34 Pneumomediastinumand Pneumothorax ........ 36 Aeroemboli ...................... 38 Ebullism ....................... 40 Review of Human Accidents Involving Explosive Decompression ................. 43 IV . Therapyin Explosive Decompression Emergencies ..... 49 A . Prophylacticand Preventive Measures ....... 49 B . Treatment of Subjects Showing Symptoms afterExplosive Decompression ......... 51 1 . LungContusion ............. 51 2 . Pneumomediastinum.Pneumothorax. andHemopneumothorax ....... 54 3 . Aeroembolism ............. 59 4 . Ebullism ................ 74 V . TherapeuticEquipment and Supplies ............ 77 VentilationKit .................... 78 Intubation Kit ..................... 78 DrugKit ...................... 79 Injection/InfusionKit ................. 80 SpecialEquipment .................. 81 Summary ............................ 83 References ........................... 87 Appendix V Rapid___ "_(Explosive) ~ Decompression~ ~ Emergencies in Pressure-Suited Sub.jects Exposure of humans to the vacuum of space simulation chambers has become a requirement in the development of full pressure suits and extravehicular assemblies. One of the hazards of such studies is rapid or explosive decompression damage to the lungs brought about by catastro- phic failure of any one of several components of the extravehicular assembly. The present analysis will cover the physical factors determining lung damage after explosive decompression of any pressurized structure sur- rounding a human; the modes of failure and physical processes in the disruption of space suits; the pathological physiology of lung damage by explosive decompression; and the therapeutic considerations in handling such emergencies in vacuum simulation chambers. I. Physical Considerations in Damage to the Lung During ExplosiveDecompression The following discussion is adapted directly from the excellent sum- mary of Luft (1 23 The severity of mechanical effects on the body in rapid decompres- sion is dependent on the change in absolute pressure, the ratio of initial to final pressure, and the rate of decompression. The latter can be defined , rather precisely on the basis of physical theory if the pressure conditions, the volume of the cabin, (suit) and the size of the aperture are known or can be (71 , 77 , 82 ,136 ) assumed . Inpresence the of humidity,decom-the pression is neither an adiabatic nor an isothermal process, but is poly- .I tropic in character. The rate of flow through the orifice may be of sub- 1, sonic or sonic velocity, according to the pressure ratio across the orifice ( 77 ' 136 ). If the critical ratio of approximately 2 to 1 is exceeded, the !I L esdape flow will be constant at the speed of sound regardless of how high the pressure head may be. The initial rate of change in pressure is deter- minedby the absolute magnitude of theinitial cabin pressure. For all 1 practical purposes, the complex factors that define the decompression transient can be resolved into two principal determinants (82 I. The first of these, which sets the absolute time scale of decompression, will be referred to as the time constant (t,) It is defined by the ratio between cabin volume (V) and the effective area of the decompression orifice (A). The velocity of sound (C) is introduced as a characteristic of flow that eliminates the effect of density. It will be seen that t must appear in units of time, all other units canceling out. C The time constant is independent of pressure. The chart in Figure 1 is a graphic solution of equation (1) relating cabin volume and effective orifice to the time constant in metric units. The second determinant is the pressure factor (P,) derived for a polytropicprocess under subsonic or sonic conditions of flow. P is a 1 function of the initial cabin pressure (P.)and the final pressure of equi- 1 librium with the environment (P ), and is independent of the- absolute pres- f sur e (82) p1 = f(+) The values for P can be read for any desired pressure ratio from the 1 curve in Figure 2. The total duration of decompression (t ) is the product d of the time constant (t ) and the pressure factor P C 1' td = tc PI The relationships expressed in equations (1) and(3),which have been verified in numerous experiments, are convenient for estimating the decom- pression time on the basis of an aircraft cabin volume..and the configuration of windows, doors, or canopy for various cabin pressures at altitudes, Similarly, the volume to orifice ratio and the time constant of any decom- pression situation can be estimated if the elapsed time of decompression 2 TlME CONSTANT .4." ,4SG AREA OF ORIFICE. m2 Figure 1. The volume of the pressure cabin relative to the effective area of the decompression orifice deter- mines the time constant of decompression. For the respiratory tract this depends on the lung volume and the flow resistance of the airways at the time of decompression. (After Luft ( 123)) and the pressure ratio P./P are known. 1f Under vacuum conditions, the duration of decompression becomes extremely long because the final equalization of pressure is very slow. Under these circumstances, the initial part of the transient where the rate of decompression is constant (constant rate time) is more meaningful, as far as biological effects are concerned, than the total duration of de- compression. As shown on Figure 3 the line of initial rate of change is extendeduntil it intersects theambient pressure P Thepoint of inter- ao' section marks a time which is evidentiy related to the initial rate of pres- sure change and the pressure difference. This "constant rate time" (tcr) can be calculated fromthe time constant (t ) and another pressure factor C 3 Figure 2. The pressure function P1 for the total time of decompression and for the L'constant rate time" (P3) as derived from the pres- sure ratio (Pc/P ) or (Pi/Pf). a (After Bancroft (12 )) (P,) which may be read from the curve so designated on Figure 2 for the appropriate decompression ratio: t = tc P3 cr If an individual were decompressed from an initial cabin pressure, Pi, to a final pressure, Pf, at altitude with closed airways in the absence of any change in his lung volume the pressure in his lungs, PL, would remain equal to P and the pressure gradient, APL, sustained byhis i' lungs and chest would be equal to the total pressure difference of decom- pres sion. APL = PL - Pf = Pi - Pf On the other hand, if the gas in
Load more

Recommended publications
  • Human Adaptation to Space
    Human Adaptation to Space From Wikipedia, the free encyclopedia Human physiological adaptation to the conditions of space is a challenge faced in the development of human spaceflight. The fundamental engineering problems of escaping Earth's gravity well and developing systems for in space propulsion have been examined for well over a century, and millions of man-hours of research have been spent on them. In recent years there has been an increase in research into the issue of how humans can actually stay in space and will actually survive and work in space for long periods of time. This question requires input from the whole gamut of physical and biological sciences and has now become the greatest challenge, other than funding, to human space exploration. A fundamental step in overcoming this challenge is trying to understand the effects and the impact long space travel has on the human body. Contents [hide] 1 Importance 2 Public perception 3 Effects on humans o 3.1 Unprotected effects 4 Protected effects o 4.1 Gravity receptors o 4.2 Fluids o 4.3 Weight bearing structures o 4.4 Effects of radiation o 4.5 Sense of taste o 4.6 Other physical effects 5 Psychological effects 6 Future prospects 7 See also 8 References 9 Sources Importance Space colonization efforts must take into account the effects of space on the body The sum of mankind's experience has resulted in the accumulation of 58 solar years in space and a much better understanding of how the human body adapts. However, in the future, industrialization of space and exploration of inner and outer planets will require humans to endure longer and longer periods in space.
    [Show full text]
  • Physiology of Decompressive Stress
    CHAPTER 3 Physiology of Decompressive Stress Jan Stepanek and James T. Webb ... upon the withdrawing of air ...the little bubbles generated upon the absence of air in the blood juices, and soft parts of the body, may by their vast numbers, and their conspiring distension, variously streighten in some places and stretch in others, the vessels, especially the smaller ones, that convey the blood and nourishment: and so by choaking up some passages, ... disturb or hinder the circulation of the blouod? Not to mention the pains that such distensions may cause in some nerves and membranous parts.. —Sir Robert Boyle, 1670, Philosophical transactions Since Robert Boyle made his astute observations in the Chapter 2, for details on the operational space environment 17th century, humans have ventured into the highest levels and the potential problems with decompressive stress see of the atmosphere and beyond and have encountered Chapter 10, and for diving related problems the reader problems that have their basis in the physics that govern this is encouraged to consult diving and hyperbaric medicine environment, in particular the gas laws. The main problems monographs. that humans face when going at altitude are changes in the gas volume within body cavities (Boyle’s law) with changes in ambient pressure, as well as clinical phenomena THE ATMOSPHERE secondary to formation of bubbles in body tissues (Henry’s law) secondary to significant decreases in ambient pressure. Introduction In the operational aerospace setting, these circumstances are Variations in Earthbound environmental conditions place of concern in high-altitude flight (nonpressurized aircraft limits and requirements on our activities.
    [Show full text]
  • HYPERBARIC MEDICINE LIBRARY KEYWORDS -See Rear Pages for Abbreviations
    HYPERBARIC MEDICINE LIBRARY KEYWORDS -see rear pages for abbreviations 3ATA 02 AIRWAY OBSTRUCTION 3ATA/6ATA ALCOHOL INTOXICATION 3-NITROTYROSINE ALKALI BURN 5-AMINOSALICYLIC ACID ALLERGIC ENCEPHALOMYELITIS 5-FLUOROURACIL ALPHA-LIPOIC ACID A-LIPOIC ACID ALPHA-TOXIN ABDOMINAL AORTIC ANEURYSM ALTERNARIOSIS ABDOMINAL COMPARTMENT SYNDROME ALTERNATIVE MEDICINE ABDOMINAL PAIN ALTERNOBARIC OXYGEN THERAPY ABI ALTERNOBARIC VERTIGO ABSIDIA CORYMBIFERA ALTITUDE ACELLULAR MATRICE ALTITUDE CAGE ACETUZOLAMIDE ALTITUDE DCS ACIDEMIA ALTITUDE PROVOCATION ACIDOSIS ALTITUDE SICKNESS ACIVICIN ALUMINUM ACCLIMATIZATION ALUM INSTILLATION ACOUSTIC EXPOSURE ALZHEIMER’S DISEASE ACOUSTIC TRAUMA AMA DIVERS ACTINOMYCOSIS AMANITA PHALLOIDES ACUTE ISCHEMIA AMINOGLYCOSIDES ACUTE KIDNEY FAILURE AMINOPHYLLINE ACUTE PERIPHERAL ARTERIAL AMNESIA INSUFFICIENCY AMPHOTERICIN B ACUTE PSYCHOSIS AMPUTATION ACUTE RADIATION EFFECTS AMRON HOOD ACUTE TRAUMATIC ISCHEMIA ANAEROBIC INFECTION ACUTE WOUNDS ANAESTHESIA ADDITIVE EFFECT ANAL MANOMETRY ADHESION MOLECULES ANAPHYLACTIC SHOCK ADIPOSE TISSUE ANASTOMOSIS ADMINISTRATIVE ANATOMIC DISTRIBUTION ADP ANEMIA ADRENALECTOMY ANEURYSM ADRIAMYCIN ANGINA AEROBIC CAPACITY ANGIOGENESIS AEROBIC INFECTION ANGIOGRAPHY AFTERDROP ANGIOPLASTY AGING ANGIOPOIETIN AIDS ANGIOSOMES AIR BREAKS ANGIOTENSIN AIR COMPRESSOR ANIMAL BITE AIR EVACUATION ANKLE SPRAIN AIR SATURATION ANKLE TO BRACHIAL INDEX AIR QUALITY ANOREXIA NERVOSA AIRCRAFT ANOXEMIA AIRCRAFT FIRES ANTERIOR SEGMENT ISCHEMIA ~ REVISED JUNE 2021 ~ ANTIBIOTICS AUTOREGULATION ANTI CANCER DRUGS AXIAL
    [Show full text]
  • Space Transportation Technology Roadmap
    WWW.NASAWATCH.COM Space Transportation Technology Roadmap A Collaboration by Government and Industry To Address U.S. Government and Commercial Space Transportation Needs Release 1.0 21 October 2010 WWW.NASAWATCH.COM WWW.NASAWATCH.COM Please direct any suggestions on this roadmap to: Paul E. Damphousse LtCol, USMC Chief of Advanced Concepts National Security Space Office Pentagon, Washington DC / Fairfax, VA W (571) 432-1411 C (571) 405-0749 [email protected] - 1 - WWW.NASAWATCH.COM WWW.NASAWATCH.COM Table of Contents EXECUTIVE SUMMARY....................................................................................................... …6 1 ROADMAP OBJECTIVES.................................................................................................... ....8 2 ROADMAP BACKGROUND............................................................................................... ..10 3 ROADMAP METHODOLOGY............................................................................................ ..18 3.1 MODELS AND REFERENCES EMPLOYED FOR THE ROADMAP…………..… ..18 3.1.1 FUNDAMENTALS OF TECHNOLOGY ROADMAPPING…………………. ..18 3.1.2 DOD RECHNOLOGY READINESS ASSESSMENTS DESKBOOK……….....18 3.1.3 SPACE-BASED SOLAR POWER STUDY…………………………………… ..19 4 PHASE 1: PRELIMINARY FOUNDATION PHASE.......................................................... ..20 4.1 SATISFYING THREE (3) ESSENTIAL CONDITIONS............................................. ..20 4.1.1 THE THREE CONDITIONS DEFINED………………………………………. ..20 4.1.2 ASSUMING THE 1ST CONDITION IS MET………………………………….
    [Show full text]
  • Chemistry 1 Stokiometry Contents
    chemistry 1 stokiometry Contents 1 John Dalton 1 1.1 Early life ................................................ 1 1.2 Early careers .............................................. 1 1.3 Scientific contributions ........................................ 1 1.3.1 Meteorology ......................................... 1 1.3.2 Colour blindness ....................................... 1 1.3.3 Measuring mountains in the Lake District .......................... 2 1.3.4 Gas laws ............................................ 2 1.3.5 Atomic theory ......................................... 2 1.3.6 Atomic weights ........................................ 3 1.3.7 Other investigations ...................................... 3 1.3.8 Experimental approach .................................... 4 1.4 Other publications ........................................... 4 1.5 Public life ............................................... 4 1.6 Personal life .............................................. 5 1.7 Disability and death .......................................... 5 1.8 Legacy ................................................. 5 1.9 See also ................................................ 6 1.10 References ............................................... 6 1.11 Sources ................................................ 7 1.12 External links ............................................. 8 2 Atomic theory 9 2.1 History ................................................. 9 2.1.1 Philosophical atomism .................................... 9 2.1.2 Dalton ............................................
    [Show full text]
  • Medical Safety Considerations for Passengers on Short-Duration Commercial Orbital Space Flights”
    “Medical Safety Considerations for Passengers on Short-Duration Commercial Orbital Space Flights” International Academy of Astronautics Study Group Chairs: Melchor J. Antuñano, M.D. (USA) Rupert Gerzer, M.D. (Germany) Secretary: Thais Russomano, M.D. (Brazil) Other Members: Denise Baisden, M.D. (USA) Volker Damann, M.D. (Germany) Jeffrey Davis M.D. (USA) Gary Gray, M.D. (Canada) Anatoli Grigoriev, M.D. (Russia) Helmut Hinghofer-Szalkay, M.D. (Austria) Stephan Hobe, Ph.D. (Germany) Gerda Horneck, Ph.D. (Germany) Petra Illig, M.D. (USA) Richard Jennings, M.D. (USA) Smith Johnston, M.D. (USA) Nick Kanas, M.D. (USA) Chrysoula Kourtidou-Papadeli, M.D. (Greece) Inessa Kozlovzkaya, M.D. (Russia) Jancy McPhee, Ph.D. (USA) William Paloski, Ph.D. (USA) Guillermo Salazar M.D. (USA) Victor Schneider, M.D. (USA) Paul Stoner M.D. (USA) James Vanderploeg, M.D. (USA) Joan Vernikos Ph.D. (USA-Greece) Ronald White, Ph.D. (USA) Richard Williams, M.D. (USA) OBJECTIVE To identify and prioritize medical screening considerations in order to preserve the health and promote the safety of paying passengers who intend to participate in short-duration flights onboard commercial orbital space vehicles. This document is intended to provide general guidance for operators of orbital manned commercial space vehicles for medical assessment of prospective passengers. Physicians supported by other appropriate health professionals who are trained and experienced in the concepts of aerospace medicine should perform the medical assessments of all prospective space passengers. In view of the wide variety of possible approaches that can be used to design and operate orbital manned commercial space vehicles in the foreseeable future, the IAA medical safety considerations are generic in scope and are based on current analysis of physiological and pathological changes that may occur as a result of human exposure to operational and environmental risk factors present during space flight.
    [Show full text]
  • Dressing for Altitude U.S
    Anybody who has watched many movies or Dennis R. Jenkins television shows has seen them—the ubiquitous About the Author silver suits worn by pilots as they explore the unknown. They are called pressure suits, and Dressing one can trace their lineage to Wiley Post or, Dressing perhaps, a bit earlier. There are two kinds of pressure suits: partial U.S. Aviation Pressure Suits–Wiley Post to Space Shuttle Pressure Suits–Wiley Post Aviation U.S. for Altitude pressure and full pressure. David Clark, once pointed out that these were not very good U.S. Aviation Pressure Suits–Wiley Post to Space Shuttle names, but they are the ones that stuck. In a partial-pressure suit, the counter-pressure is not as complete as in a full-pressure suit, but it Dennis R. Jenkins is placed so that shifts in body fl uids are kept One of the unsigned authors of an Air Force history of within reasonable limits. On the other hand, a the Wright Air Development Center wrote an epilogue full-pressure suit, which is an anthropomorphic that conveyed the awe associated with aviation pressure pressure vessel, creates an artifi cial environment suits during the mid-1950s. “The high point in the for the pilot. development of the altitude suit was reached on June for 17, 1954 when Maj. Arthur Murray rode the rocket- One type of pressure suit is not necessarily propelled X-1A to an altitude in excess of 90,000 feet. “better” than the other, and both partial-pressure When Murray reached the peak of his record setting and full-pressure suits are still in limited use fl ight, he was atop more than 97 percent of the atmo- around the world.
    [Show full text]
  • NASA SP-118 SPACE-CABIN ATMOSPHERES 3 -2 8- Part ;IV,Pngineering Tradeoffs of One- Grsus Two-Gas Systems6
    NASA SP-118 SPACE-CABIN ATMOSPHERES 3 -2 8- Part ;IV,pngineering Tradeoffs of One- Grsus Two-Gas Systems6 A literature review by 6 Emanuel M. RothfiA4.D. Prepared under contract for NASA by Lovelace Foundation for Medical Education and Research, Albuquerque, New NIexico Scientific and Technical Information Division OFFICE OF TECHNOLOGY UTILIZATION 9 1967 10 c" )NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Washington, D.C.3 PREC€t?iNG PAGE BLANK NOT FILMQ. Foreword THISREPORT is Part Iv, the last volume of a study on Space-Cabin Atmospheres, conducted under sponsorship of the Directorate, Space Medicine, Office of Manned Space Flight, National Aeronautics and Space Administration. Part I, “Oxygen Toxicity,” was published as NASA SP47, Part 11, “Fire and Blast Hazards,” as NASA SP-48, and Part 111, “Physiological Factors of Inert Gases,” as NASA SP-117. This document provides a readily available summary of the open literature in the field. It is intended primarily for biomedical scientists and design engineers. The manuscript was reviewed and evaluated by leaders in the scientific com- munity as well as by the NASA staff. As is generally true among scientists, there was varied opinion about the author’s interpretation of the data compiled. There was nonetheless complete satisfaction with the level and scope of scholarly re- search that went into the preparation of the document. Thus, for scientist and engineer alike it is anticipated that this study will become a basic building block upon which research and development within the space community may proceed. JACK BOLLERUD Brigadier General, USAF, MC Acting Director, Space Medicine Office of Manned Space Flight iii FXECEDING PAGE BLANK NOT FILMX.
    [Show full text]
  • Medical Safety Considerations for Passengers on Short-Duration Commercial Orbital Space Flights”
    “Medical Safety Considerations for Passengers on Short-Duration Commercial Orbital Space Flights” International Academy of Astronautics Study Group Chairs: Melchor J. Antuñano, M.D. (USA) Rupert Gerzer, M.D. (Germany) Secretary: Thais Russomano, M.D. (Brazil) Other Members: Denise Baisden, M.D. (USA) Volker Damann, M.D. (Germany) Jeffrey Davis M.D. (USA) Gary Gray, M.D. (Canada) Anatoli Grigoriev, M.D. (Russia) Helmut Hinghofer-Szalkay, M.D. (Austria) Stephan Hobe, Ph.D. (Germany) Gerda Horneck, Ph.D. (Germany) Petra Illig, M.D. (USA) Richard Jennings, M.D. (USA) Smith Johnston, M.D. (USA) Nick Kanas, M.D. (USA) Chrysoula Kourtidou-Papadeli, M.D. (Greece) Inessa Kozlovzkaya, M.D. (Russia) Jancy McPhee, Ph.D. (USA) William Paloski, Ph.D. (USA) Guillermo Salazar M.D. (USA) Victor Schneider, M.D. (USA) Paul Stoner M.D. (USA) James Vanderploeg, M.D. (USA) Joan Vernikos Ph.D. (USA-Greece) Ronald White, Ph.D. (USA) Richard Williams, M.D. (USA) ABSTRACT This report identifies and prioritizes medical screening considerations in order to preserve the health and promote the safety of paying passengers who intend to participate in short- duration flights (up to 4 weeks) onboard commercial orbital space vehicles. This includes the identification of pre-existing medical conditions that could be aggravated or exacerbated by exposure to the environmental and operational risk factors encountered during launch, inflight and landing. Such risk factors include: acceleration, barometric pressure, microgravity, ionizing radiation, non-ionizing radiation, noise, vibration, temperature and humidity, cabin air, and behavioral and communications issues. Because of the wide variety of possible approaches that can be used to design and operate manned commercial orbital space vehicles, it is very difficult to make unequivocal recommendations on specific medical conditions that would not be compatible with ensuring safety during orbital space flight.
    [Show full text]
  • An Overview of Space Medicine P
    British Journal of Anaesthesia, 119 (S1): i143–i153 (2017) doi: 10.1093/bja/aex336 Prehospital Care Downloaded from https://academic.oup.com/bja/article-abstract/119/suppl_1/i143/4638468 by guest on 11 February 2019 An overview of space medicine P. D. Hodkinson1,2,*, R. A. Anderton3, B. N. Posselt1 and K. J. Fong4 1Royal Air Force Centre of Aviation Medicine, RAF Henlow, Bedfordshire SG16 6DN, UK, 2Division of Anaesthesia, Department of Medicine, University of Cambridge, Box 93, Addenbrooke’s Hospital, Cambridge CB2 2QQ, UK, 3Civil Aviation Authority, Gatwick Airport South, Aviation House, Crawley, Gatwick RH6 0YR, UK and 4University College London Hospital, 235 Euston Road, Bloomsbury, London NW1 2BU, UK *Corresponding author. E-mail: [email protected] Abstract Space medicine is fundamental to the human exploration of space. It supports survival, function and performance in this challenging and potentially lethal environment. It is international, intercultural and interdisciplinary, operating at the boundaries of exploration, science, technology and medicine. Space medicine is also the latest UK specialty to be recognized by the Royal College of Physicians in the UK and the General Medical Council. This review introduces the field of space med- icine and describes the different types of spaceflight, environmental challenges, associated medical and physiological effects, and operational medical considerations. It will describe the varied roles of the space medicine doctor, including the conduct of surgery and anaesthesia, and concludes with a vision of the future for space medicine in the UK. Space medicine doctors have a responsibility to space workers and spaceflight participants. These ‘flight surgeons’ are key in developing mitigation strategies to ensure the safety, health and performance of space travellers in what is an extreme and hazardous environment.
    [Show full text]
  • Respiratory Physiology and Protection Against Hypoxia
    CHAPTER 2 Respiratory Physiology and Protection Against Hypoxia Jeb S. Pickard and David P. Gradwell There is something fascinating about science. One gets such a wholesale return of conjecture from such a trifling investment of fact. —Mark Twain, Life on the Mississippi RESPIRATORY PHYSIOLOGY support poikilothermic organisms but, even in a tumbling mountain stream, the oxygen content of water is trivial Respiration is the process by which an organism exchanges compared to air. Also, for all but the simplest of multicellular gases with the environment and, for most aerobic organisms, organisms, the solubility of oxygen requires that the delivery the critical portion of respiration consists of ensuring an system includes a carrier molecule. adequate supply of oxygen. There is considerable geologic In humans, the limbs of the oxygen delivery system evidence that the Earth’s original atmosphere was anoxic, consist of the following: and it seems probable that life began under anaerobic conditions. Because habitable environments available to • Ventilation—the process whereby pulmonary alveoli ex- anaerobic organisms became relatively scarce due to the change gas with the atmosphere. Problems that may impact shift toward an oxidizing atmosphere, the development of this part of the system include inadequate atmosphere, enzyme systems capable of both utilizing and detoxifying such as a hypoxic or hypercarbic environment, and airway oxygen was a practical necessity. This evolutionary step obstruction. had an added ramification because the utilization of a • Pulmonary diffusion—the process whereby gases are reactive element such as oxygen unleashed a source of exchanged between the alveolus and the pulmonary energy that allowed the development of ever more complex capillary.
    [Show full text]
  • Jonathan B. Clark, M.D., M.P.H. (Page 1 of 5)
    Curriculum Vita — Jonathan B. Clark, M.D., M.P.H. (Page 1 of 5) Jonathan B. Clark, M.D., M.P.H. Associate Professor of Neurology Baylor College of Medicine Faculty Member, Center for Space Medicine Baylor College of Medicine CONTACT INFORMATION Jonathan B. Clark, M.D., M.P.H. Center for Space Medicine Baylor College of Medicine BioScience Research Collaborative 6500 Main St., Suite 910 Houston, Texas 77030 Tel: 713-798-8809 Email: [email protected] CERTIFICATIONS National Board of Medical Examiners American Board of Psychiatry and Neurology, Neurology American Board of Preventive Medicine, Aerospace Medicine EDUCATION M.D., Uniformed Services University of the Health Sciences, Md. M.P.H., University of Alabama, Birmingham, Ala. Internship, Internal Medicine, Naval Hospital, Bethesda, Md. Residency, Neurosurgery, Naval Hospital, Bethesda, Md. Residency, Neurology, Naval Hospital, Bethesda, Md. JOURNAL PUBLICATIONS 1. Asrar FM, Saint-Jacques D, Chapman HJ, Williams D, Ravan S, Upshur R, et al. Can space-based technologies help manage and prevent pandemics? Nat Med. 2021;27(9):1489-90. PMID: 34518675. 2. Kramer LA, Hasan KM, Sargsyan AE, Marshall-Goebel K, Rittweger J, Donoviel D, et al. Quantitative MRI volumetry, diffusivity, cerebrovascular flow and cranial hydrodynamics during head down tilt and hypercapnia: The SPACECOT study. J Appl Physiol (1985). 2017;122(5):1155-66. PMID: 28209740. 3. Strangman GE, Zhang Q, Marshall-Goebel K, Mulder E, Stevens B, Clark JB, et al. Increased cerebral blood volume pulsatility during head-down tilt with elevated carbon dioxide: The SPACECOT Study. J Appl Physiol (1985). 2017;:jap 00947 2016. PMID: 28360122. 4. Bershad EM, Anand A, DeSantis SM, Yang M, Tang RA, Calvillo E, et al.
    [Show full text]