Exercise Physiology I - Hyperbaric Conditions

Department of Health Sciences and Technology Institute of Human Movement Sciences and Sport Hier steht der Titel der Präsentation Exercise Physiology I – AS24 Dieser kann, wenn immer nötig, über zwei oder sogar drei Zeilen laufen Hyperbaric conditions – Div...

Department of Health Sciences and Technology Institute of Human Movement Sciences and Sport Hier steht der Titel der Präsentation Exercise Physiology I – AS24 Dieser kann, wenn immer nötig, über zwei oder sogar drei Zeilen laufen Hyperbaric conditions – Diving Prof. Dr. Beat Muster Prof. Dr. Beat Muster Funktion des Präsentierenden Funktion des Präsentierenden TT. Monat JJJJ, Ort TT. Monat Prof. JJJJ,M.Ort Christina Spengler, PhD, MD Learning Objectives Students are able to discuss physiological changes associated with (cold) water immersion discuss physiological changes associated with an increasing hyperbaric environment (depth) critically reflect on (patho-)physiological similarities and differences between free diving and scuba diving, risks and preventive measures of accidents Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 2 Cardio-respiratory changes with partial water immersion Changes as a result of increased hydrostatic pressure on the human system: Venous return ↑ Stroke volume ↑ and heart rate ↓ nevertheless, cardiac output ↑ Pulmonary blood volume ↑ Respiratory muscle work ↑ Diuresis ↑ (in response to the above) The colder the water, the more heart rate is reduced and the more optimal functioning of muscle fibers is affected à the higher the risk of arrhythmia! Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 3 Cardio-respiratory response to sudden partial cold water immersion - The Cold Shock = Combination of different cardio-respiratory reflexes when suddenly exposed to cold (< 25 oC) water on the whole body (except head) Initial deep inspiration à substantial hyperventilation (the colder the water, the larger the simulus; peaks at ∼10 oC) Increase in functional residual capacity (FRC) à Increase in Air Hunger Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 4 Cardio-respiratory changes with full water immersion – The Diving Reflex Physiological response to cold-water stimulation of face and eyes: Apnoea Bradykardia Peripheral vasoconstriction Aim: Reduction of V̇O2 Extension of underwater survival time Effectiveness of the diving reflex: Diving mammals > Humans (Children > Adults) Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 5 Effects of cold water - Thermoregulation Heat conduction in water = 26x heat conduction in air In total (thermal radiation, heat conduction, convection [main factor], evaporation): à Heat loss in water is 4x faster than in air Exampe: Immersion at 15 oC è Cory Body Temperature decreases by - 2.1 oC / hour Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 6  Effects of cold water - Muscle function and metabolism Changes in cold muscles: Contraction velocity ↓ Neuromuscular coordination ↓ (fiber recruitment is less efficient) Development of fatigue ↑ Remember: Increased risk of cardiac arrhythmia! Metabolism in the cold: Epinephrin- and Norepinephrin-secretion ↑↑ Lipolysis ↑ à free fatty acids in blood ↑ Anaerobic glycolysis (use of muscle glycogen) ↑ Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 7  Effects of hyperbaric conditions on air-filled cavities McArdle, Katch, Katch. Exercise Physiology 30 m Boyle's Law see open/closed bottle under water è Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 8 Effects of hyperbaric conditions on air-filled cavities https://www.youtube.com/watch?v=t8wFIMbMJvs&NR=1 Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 9 Barotrauma in response to hypobaric conditions Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 10  Barotrauma in response to hypobaric conditions è Equalize Pressure !!! Blockage may result in: Pain Rupture of small vessels and membranes in the middle ear or sinuses Rupture of ear drum Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 11 Barotrauma in response to hypobaric conditions è Equalize Pressure !!! Without equalization: Blood vessels in eyes and skin may rupture Eyes may be sucked out è Swim goggles are not useful è Facemask needs to include nose X Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 12 Free diving (apnea diving) – Limits and risks http://www.aidainternational.org variable weight 1. Breathhold apnea (VWT) 2. Hyperbaric effects on the lung 3. Important factors regarding Snorkel Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 13 Free diving (apnea diving) – Limits and risks http://www.aidainternational.org variable weight 1. Breathhold – Limits? apnea (VWT) 2. Hyperbaric effects on the lung 3. Important factors regarding Snorkel Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 14 Static apnea – Guinness Book of World Records https://www.youtube.com/watch?v=slYb1wta-pg First World Record in Breathholding in 1959 … Robert Foster 13 min 42 s... after 30 min of breathing pure O2 afterbreathing pure oxygen World Record in Static apnea 27.3.2021 Budimir Sobat Why breathing O2 at sea level where SpO2 is nearly 100%? 24 min 37 s What else could prolong apnea? Until recently the Swiss Peter Colat held this record 21:33.32 (since 17.9.11) Peter Colat live in Science City ETHZ https://video.ethz.ch/campus/treffpunkt-science-city/2019/herbst/vorlesungen/ Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 15 Static Apnea – Word Records without oxygen breathing Molchanova, 53, holds 41 world records in freediving – diving without breathing apparatus – and can hold her breath for nine minutes. In May, she dived to a depth of 71 metres in waters off Egypt … (2015) Наталья Вадимовна Молчанова; 8 May 1962 – 2 August 2015 wikipedia à Limits to apnea? Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 16 www.aidainternational.org – Nov. 2022 Limits to apnea Changes in blood gases: Increase in PaCO2 > Decrease in PaO2 Suppression of respiratory drive and its feedback Fowler, J Appl Physiol, 1954 Level of motivation of the person Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 17 Risk of hyperventilation prior to apnea – blood gases & pressure change Stimulus to terminate breathhold and ascend Eichhorn & Leyk, Dt. Ärzteblatt Intl., 2015 Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 18 Free diving (apnea diving) – Limits and risks http://www.aidainternational.org variable weight 1. Breathhold – Limits? apnea (VWT) 2. Hyperbaric effects on the lung 3. Important factors regarding Snorkel Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 19 Diving depth and lung volume Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 20 Diving depth and lung volume Male 20-30 y TLC = 6.7L RV = 23.9% Pmax = 4.2 atm max. depth = 32 m Male 50-60 y TLC = 6.6L RV = 33.3% Pmax = 3.0 atm max. depth = 20 m Female 20-30 y TLC = 5.8L RV = 24.2% Pmax = 4.1 atm max. depth = 31 m Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 21 Free diving (no limits) – World records Not without training! http://aida.medical.tilda.ws/ Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 22 Free diving (apnea diving) – Limits and risks http://www.aidainternational.org variable weight 1. Breathhold – Limits? apnea (VWT) 2. Hyperbaric effects on the lung 3. Important factors regarding snorkel Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 23  Important snorkel considerations Length (≤ 35 cm) Valve pro/con ? Diameter Adults: 18 - 25 mm Color ? Children: 15 - 18 mm Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 24 Free diving (apnea diving) – Key points The main respiratory drive is PaCO2. (careful with hyperventilation!) Diving depth is limited by TLC:RV (except for diving-trained athletes = exceptions!) Equalizing pressure in air-filled cavities is always essential! Using proper snorkel and nose-covering mask are always essential! Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 25 SCUBA - Diving The Self-Contained Underwater Breathing Apparatus was invented 1942/1943 (then named AquaLung) by Jacques Cousteau (1910-1997; naval lieutenant) Wikipedia and Emile Gagnan (1900-1979; engineer of natural gas company) Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 26 SCUBA-Diving - Additional Risks 4 0 m t a t. d e n m i n n c i r 7 i t e A n th a f u y s ! d e p y g c k Lu Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 27 Open-circuit demand SCUBA 10 L – bottle air with 200 bar à Lasts for how long? Volume without pressure: à 2000 L Resting ventilation ca. 10 L/min à 3.5 h (200 min) BUT: 10 m depth = 2 bar = 1000 L = 100 min 30 m depth = 4 bar = 500 L = 50 min 40 m depth = 5 bar = 400 L = 40 min Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 28 Gases under pressure during hyperbaric conditions O2 poisening N2 narcosis Decompression – mechanical problems Decompression sickness à How can we avoid the above? à How can we treat the above? Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 29 Gases under pressure during hyperbaric conditions Depth Total Pressure PiO2 %O2 PiN2 (m) (mmHg) (mmHg) to reach sealevel-PiO2 (mmHg) 0 760 159 20.9 600 10 1'520 318 10.5 1'201 20 2'280 477 7.0 1'802 30 3'040 636 5.3 2'402 Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 30 SCUBA-Diving - additional risk: Oxygen poisening PO2 > 318 mmHg (> 10m depth) Symptoms: Visual distortion Rapid and shallow breathing Convulsions, Seizures Because: O2 – removal from hemoglobin ↓ CO2- uptake from tissue into blood ↓ High PO2 causes vasoconstriction to cerebral vessels Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 31 SCUBA-Diving - additional risk: Nitrogen narcosis Nitrogen acts like anaesthetic gas Similar to alcohol intoxication Depth and pressure worsens 'intoxication' (every 15m, one glas Martini on empty stomach) >30 m: Impaired judgement if longer at >30 m: Replace N2 by Helium Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 32 SCUBA-Diving - additional risk: Lung injury "Lungenriss bei Notaufstieg!" How come? Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 33 SCUBA-Diving - additional risk: Lung injury SCUBA only SCUBA only 34 Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 34 Lung tissue rupture or pneumothorax during ascent è Closed glottis during ascent (panic!) è Air expands with decreasing ambient pressure è Lung tissue ruptures possible with leak to the intra-pleural space à pneumothorax Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 35 Lung tissue rupture or pneumothorax during ascent Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 36 SCUBA-Diving - additional risks: Bubbles, Emboli and Decompression sickness as free diving SCUBA only as as free diving free diving SCUBA only SCUBA only SCUBA only Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 37 37 SCUBA-Diving - additional risk: Decompression sickness as Symptoms: free diving Aching in elbows, shoulders, and knees Mechanism: as free diving ascending too rapidly (pressure release is too fast, dissolved N2 is released from liquid, cannot travel to lung) SCUBA only local build up of N2-bubbles in tissue à local pain bubbles can form N2-emboli (in blood) à travel à close vessels SCUBA only Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 38 38 SCUBA-Diving - additional risk: Decompression sickness (special risk) Risk of N2-embolus traveling to brain is increased 3-fold in persons with open foramen ovale. as Prevalence of open foramen ovale in general population: 25% free diving as free diving SCUBA only SCUBA only Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 39 suva 39 SCUBA-Diving - additional risks: Bubbles, Emboli and Decompression sickness as free diving SCUBA only è DO NOT ASCEND as as TOO FAST! free diving free diving SCUBA only SCUBA only SCUBA only Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 40 40 Research for prevention of decompression sickness John Scott Haldane (1860-1936, Scottish physiologist) Respiratory Researcher Development of methods for the assessment of respiration, blood gases and oxygen consumption First decompression table (1908; for the British Admirality; used until 1950ies on grounds of experiments with goats and other animals) "Ewige Nullzeit" (no-stop dive when < 10 m) Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 41 Research for prevention of decompression sickness at USZ ! Prof. Albert A. Bühlmann Gas-Lager Kompressoren Tauchforschung 1959-1994 1964 offerierte die Shell International ihre Sauerstoff Unterstützung zur Durchführung von gezielter Hochdruck- 1-Personen Kammer systematischer Forschung im Bereich der Transportkammer Vor- Dekompressions Tauchmedizin durch Professor A. A. Kammer Kammer Bühlmann, Med. Klinik Universitätsspital spez. Gasgemisch Zürich (USZ). à Druckkammerlabor am Kantonsspital He-Rück- Zürich, KSZ (heute USZ) in spartanischer gewinnung med. Ausführung im Keller des Schwestern- Luft Über- Gas- Hochhauses. wachung Analyse Grundthema der Forschung: Wohlbefinden und Leistungsfähigkeit des Menschen in einer hinsichtlich Druck und Helium Gaszusammensetzung abnormalen Atmosphäre: Damit ergaben sich viele Beziehungen zur Atem-, Kreislauf- und Kontrolle / Monitoring Höhenphysiologie. Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 42  Research for prevention of decompression sickness – symptoms live! https://www.srf.ch/play/tv/mtw/video/mtw-menschen-technik-wissenschaft-vom-05-05-1976?urn=urn:srf:video:e844be89-a23b-4147-ac34-0ae40a902fe6 SCUBA - Diving 43 Prevention of decompression sickness – Charts and Diving Computers Chart and computers showing time to ascend from various depths Treat by Hyperoxia Placing diver in recompression chamber Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 44  Hyperbaric chambers Pulstipp 13.5.04 Druckkammern stehen unter Spar-Druck Gestrichene Subventionen gefährden die Sicherheit von Tauchern in der Schweiz Unispital Zürich (USZ) Ausser Betrieb Unispital Genf (HUG) 24h-Betrieb Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 45 Air-Rescue of divers with decompression sickness – a Challenge …. Wrack... in ungefähr 60 Metern Tiefe … stieg einer der beiden Taucher aus ungeklärten Gründen zu schnell zur Oberfläche auf. … Dank seiner Taucherfahrung … alarmierte nach dem Auftreten der ersten Symptome der Taucherkrankheit … die Rega-Einsatzzentrale … Rettungshelikopter aus Lausanne transportierte den Taucher ins Universitätsspital Genf HUG … Der zweite Taucher … defekten Tauchuhr … konnte rechtzeitig wieder abtauchen und einen kontrollierten Aufstieg durchführen. … Symptome der Taucherkrankheit unter Umständen erst mit Stunden Verspätung … vorsichtshalber zur Überwachung ebenfalls ins HUG geflogen. Die Rettung der beiden Taucher verlangte ein grosses Mass an Koordination zwischen den Einsatzkräften, da bei Tauchunfällen nicht nur die Zeit kritisch, sondern auch viel Spezialwissen nötig ist. So waren denn neben der Rega und der Notfallzentrale 144 Riviera auch die medizinischen Spezialisten des Divers Alert Network Europe (DAN) gefragt. What is important? Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 46 Air-Rescue of divers with decompression sickness – a Challenge https://www.rega.ch/de/medien/medienmitteilungen/detail.aspx?id=2618 Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 47 Diving – Risks-Summary as free diving SCUBA only as as free diving free diving SCUBA only SCUBA only SCUBA only Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 48 48 After this Lecture, ask yourself "Can I …. " quantify the relationship between the depth underwater, gas pressure and volume? discuss the rationale for snorkel dimensions and underwater breathing depth? describe factors that limit the depth of a breath-hold dive? describe the effects of hyperventilation on breath-hold duration and the mechanisms associated with the risk of hyperventilation prior to diving? outline physiological changes with water immersion and the evidence that supports a “diving reflex” being present also in humans explain causes and symptoms of mask squeeze, pneumothorax, nitrogen narcosis, oxygen poisoning, air embolism, pneumothorax and decompression sickness? discuss the purpose and influencing factors of the decompression schedule? describe the rationale for saturation diving and describe the special aspects of the environment the diver lives in for prolonged dives to exceptional depths? Exercise Physiology I - Exercise in hyperbaric and hypobaric conditions - diving and altitude 49 Thank you for your attendance 50