HYPEROXIA AND HYPERBARIA

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HYPEROXIA AND HYPERBARIA
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HYPEROXIA (BREATHING OXYGEN ENRICHED AIR)
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BREATH-HOLDING EXERCISE

• BENEFICIAL EFFECTS DURING BREATH-HOLDING EXERCISE
  DUE TO THE INCREASED CARBON DIOXIDE AND HYDROGEN
  IONS CONCENTRATIONS THAT ARE EXPIRED PRIOR TO
  EXERCISE (HALDANE EFFECT) THEREBY REDUCING
  RESPIRATORY STIMULATORS AND THE DESIRE FOR
  RESPIRATION
• INCREASED PERFORMANCE TIME DURING BREATH-HOLDING
  EXERCISE

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NORMAL (BREATHING O2) EXERCISE

• DURING SUBMAXIMAL EXERCISE
• - LOWER HEART RATE
• - LOWER BLOOD LACTATE ACCUMULATION
• - LOWER VENTILATION RATE
• - INCREASED WORK TIME TO
• EXHAUSTION
• DURING MAXIMAL EXERCISE
• - GREATER ENDURANCE CAPACITY
• - INCREASED WORK TIME TO
• EXHAUSTION

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NORMAL (BREATHING O2) EXERCISE

• BENEFITS RELATED TO THE INCREASED PARTIAL
  PRESSURE OF OXYGEN, WHICH INCREASES THE OXYGEN
  TRANSPORTED BY HEMOGLOBIN AND DISSOLVED IN THE
  PLASMA (PHYSICAL SOLUTION) AS WELL AS INCREASES
  THE DIFFUSION OF OXYGEN ACROSS THE
  ALVEOLAR-CAPILLARY AND MUSCLE TISSUE-CAPILLARY
  MEMBRANES

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OXYGEN-BREATHING DURING RECOVERY

• MINIMAL EFFECTS ON EITHER THE RECOVERY PROCESS OR
  ON SUBSEQUENT WORK BOUT PERFORMANCES
• NO PHYSIOLOGICAL BASIS FOR THE USE OF OXYGEN
  DURING RECOVERY ALTHOUGH THERE MAY BE A
  PSYCHOLOGICAL EFFECT

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HYPERBARIA
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HISTORY OF UNDERWATER SUBMERSION
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HYPERBARIA

• FOR EVERY DECREASE OF 10 METERS IN SEA WATER AND
  10.4 METERS IN FRESH WATER, PRESSURE INCREASE BY
  ONE ATMOSHPHERE (1 ATM) OR 760 mmHG

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• OPEN-CIRCUIT SCUBA (SELF-CONTAINED UNDERWATER
  BREATHING APPARATUS) IS THE MOST WIDELY USED
  APPARATUS BY DIVERS
• SCUBA USES MIXED GASES WHICH ARE SUPPLIED TO THE
  LUNGS AT A PRESSURE EQUIVALENT TO AMBIENT
  (SURROUNDING) PRESSURE
• SCUBA HAS INCREASED THE DEPTH AND DURATION OF
  DIVING

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• HOWEVER, THE MOST COMMON WAY TO ENTER THE WATER
  IS BREATH-HOLD DIVING FOR DURATIONS UP TO 3
  MINUTES OR LONGER AND DEPTHS UP TO 70 METERS OR
  MORE

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IMPORTANT LAWS FOR UNDERSTANDING THE EFFECTS OF
HYPERBARIA ON THE HUMAN BODY
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• BOYLES LAW - PRESSURE AND VOLUME OF A GAS ARE
  INVERSELY RELATED
• INCREASE PRESSURE, DECREASE VOLUME
• DECREASE PRESSURE, INCREASE VOLUME
• CHARLES LAW - ASSUMING PRESSURE REMAINS
  CONSTANT, THE VOLUME OF A GAS IS PROPORTIONAL TO
  ABSOLUTE TEMPERATURE OR IF VOLUME REMAINS
  CONSTANT, PRESSURE IS DIRECTLY PROPORTIONAL TO
  ABSOLUTE TEMPERATURE

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• DALTONS LAW - THE TOTAL PRESSURE EXERTED BY A
  MIXTURE OF GASES IS EQUAL TO THE SUM OF THE
  INDIVIDUAL PRESSURES EXERTED BY EACH OF THE GASES
  COMPRISING THE GAS MIXTURE
• PB PO2 PCO2 PN2 Pother gases
• THE AMOUNT OF GAS THAT A FLUID WILL ABSORB UNDER
  PRESSURE VARIES IN DIRECT PROPORTION TO THE
  PARTIAL PRESSURE OF THE GAS

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• HENRYS LAW - FOR A GAS OF LOW SOLUBILITY
  (DECREASED LIKELIHOOD OF BEING DISSOLVED AND
  THEREFORE CAN SATURATE TISSUES) , AT A GIVEN
  TEMPERATURE THE CONCENTRATION IN THE LIQUID WILL
  BE NEARLY PROPORTIONAL TO THE PRESSURE OF THAT
  GAS IN THE GAS PHASE
• GASES WITH LOW SOLUBILITY REQUIRE LESS TIME TO
  SATURATE A LIQUID THAN GASES OF A HIGHER
  SOLUBILITY
• THE LONGER AND DEEPER THE DIVE, THE GREATER THE
  SATURATION OF THE BODYS TISSUES WITH GASES

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BREATH-HOLD (BH) DIVING

• AS ONE DESCENDS THE INCREASE IN PRESSURE IS
  EVENLY TRANSMITTED THROUGHOUT THE BODYS TISSUES
  COMPRESSING COMPLIABLE GAS CONTAINING CAVITIES
  (BOYLES LAW)
• GASTROINTESTINAL TRACT IS VERY COMPLIANT OR
  COMPRESSIBLE
• IN THE AIRWAYS, LUNGS, SINUSES, AND MIDDLE EAR,
  THE INTERNAL PRESSURE IS EQUALIZED WITH AMBIENT
  PRESSURE BY VENTING AIR BETWEEN THE COMPRESSIBLE
  (LUNGS) AND NONCOMPRESSIBLE CAVITIES.

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• GENERALLY, THE VASCULATURE IS IN EQUILIBRIUM WITH
  EXTERNAL PRESSURE
• VESSELS WHICH PASS THROUGH INTERNAL CAVIITIES
  WITH LOWER PRESSURE MAY RUPTURE CAUSING
  HEMORRHAGING
• BAROTRAUMA (INJURIES RESULTING FROM PRESSURE
  DIFFERENCES ACROSS THE WALLS OF GAS-FILLED
  CAVITIES) MAY CAUSE PAIN AND TISSUE DAMAGE

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• AS THE DEPTH OF THE DIVE INCREASES, LUNG VOLUME
  TENDS TO DECREASE
• AT ABOUT 20 METERS LUNG VOLUME TENDS TO EQUAL
  RESIDUAL VOLUME

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• BELOW 20 METERS THERE IS AN INCREASED LIKELIHOOD
  THAT PULMONARY VESSELS MAY RUPTURE CAUSING
  CONGESTION, EDEMA, AND HEMORRHAGING
• DURING BH DIVING THE LOWER INTRAHORACIC PRESURE
  MAY RESULT IN AN INCREASE IN BLOOD FLOW TO THE
  THORACIC CAVITY AND THE DIAPHRAGM MAY BECOME
  DISPLACED TOWARD THE HEAD THEREBY FURTHER
  REDUCING LUNG VOLUME (AND HENCE INCREASING
  PRESSURE DUE TO BOYLES LAW) AND PREVENTING THE
  RUPTURE OF PULMONARY VESSELS

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• AT SEA LEVEL, BREATH HOLDING
• DECREASED ARTERIAL AND ALVEOLAR PO2
• INCREASED ARTERIAL AND ALVEOLAR PC02
• INCREASED ARTERIAL PC02 AND
• DECREASED ARTERIAL P02 EVENTUALLY
  STIMULATES VENTILATION (BREATHING)

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BREATH-HOLD DIVING

• DURING THE DESCENT BOTH ALVEOLAR PO2 AND PCO2
  INCREASE DUE TO BOYLES LAW
• INCREASED ALVEOLAR PC02 MAY REVERSE THE GRADIENT
  BETWEEN THE LUNGS AND BLOOD AND CO2 MAY MOVE BACK
  INTO THE BLOOD

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• MAXIMUM ALVEOLAR P02 VALUE ACHIEVED IS DEPENDENT
  ON A HIGH INITIAL SURFACE VALUE, LOW METABOLIC
  RATE, GREATER DEPTH OF DIVE, AND
  DURATION/QUICKNESS OF DESCENT
• QUICKER THE DESCENT, THE HIGHER THE PO2 VALUE
  ACHIEVED AND DEPLETION OF O2 IS MINIMIZED

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• AT THE BOTTUM OF THE DIVE, O2 MOVES OUT OF THE
  LUNGS AT A RATE DICTATED BY METABOLIC DEMANDS AND
  ALVEOLAR PCO2 TENDS TO EQUALIZE WITH ARTERIAL PCO2

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• DURING THE ASCENT, ALVEOLAR P02 DECREASES WHICH
  MAY STOP THE DIFFUSION OF O2 INTO THE BLOOD
• ALVEOLAR PC02 ALSO DECREASES WHICH WILL INCREASE
  THE TRANSFER OF CO2 FROM THE BLOOD INTO THE LUNGS
  AND MAY LEAD TO A DECREASE IN VENTILATORY DRIVE

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• MAXIMUM DURATION OF A BH DIVE (RANGE FROM 20-270
  SECONDS) CAN BE INCREASED BY
• PSYCHOLOGICAL FACTORS
• LARGE LUNG VOLUME AND HIGH ALVEOLAR AND
  ARTERIAL PO2 LEVELS
• LOW ARTERIAL PC02 AS PCO2 STIMULATES
  RESPIRATION
• REDUCED METABOLIC RATE ALTHOUGH PHYSICAL
  MOVEMENT MAY CAUSE CONSCIOUS DISSOCIATION AND
  THUS DELAY THE BREAKING POINT
• INCREASED PRESSURE WHICH WILL INCREASE ALVEOLAR
  AND ARTERIAL O2 WHICH INCREASES TOLERANCE TO
  HYPERCAPNIA
• INHALATION OF OXYGEN ENRICHED GAS PRIOR TO DIVE
• HYPERVENTILATION PRIOR TO DIVE WHICH WILL
  DECREASE ALVEOLAR AND ARTERIAL PCO2 LEVELS AND
  HENCE VENTILATORY DRIVE MAY BE DANGEROUS AS
  LIKELIHOOD OF HYPOXIA TO THE BRAIN IS INCREASED,
  PARTICULARLY DURING THE ASCENT PHASE OF THE DIVE
  WHEN THERE IS ALREADY DECREASED MOVEMENT OF
  OXYGEN INTO THE BLOOD

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METABOLIC, CARDIAC, AND CIRCULATORY FUNCTION
DURING BH DIVING

• NO CHANGE IN OXYGEN UPTAKE RATE, CARDIAC OUTPUT,
  AND OXYGEN EXTRACTION
• BRADYCARDIA DUE TO INCREASED VAGUS DOMINANCE OF
  HR AS PNS IS STIMULATED BY COLD WATER AND APNEA
• INCREASED STROKE VOLUME DUE TO ENHANCED
  VENOCONSTRICTION AND RETURN OF BLOOD FLOW THEREBY
  INCREASING END-DIASTOLIC VOLUME
• INCREASED PERIPHERAL VASOCONSTRICTION (26-53)
  WHICH INCREASES BLOOD PRESSURE
• INCREASED VENOCONSTRICTION AND VASOCONSTRICTION
  DUE TO INCREASED SNS RELEASE OF NOREPINEPHRINE

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ADAPTATIONS TO BH DIVING

• REPEATED EXPOSURE TO HIGH PRESSURE, HYPOXIA, AND
  HYPERCAPNIA REDUCES THE STRESS OF BH DIVING AND
  ENHANCES DIVING PERFORMANCE
• REDUCED STRESS OF BH DIVING AND ENHANCED DIVING
  PERFORMANCE ARE DUE TO

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• INCREASED VITAL CAPACITY AND DECREASED RESIDUAL
  LUNG VOLUME THEREBY INCREASING THE RATIO OF TOTAL
  LUNG CAPACITY TO RESIDUAL LUNG VOLUME RESULTING
  IN GREATER LUNG COMPLIANCE
• INCREASED STRENGTH IN THE RESPIRATORY MUSCLES
  (DIAPHRAGM AND EXTERNAL INTERCOSTALS)
• DECREASED CHEMOSENSITIVITY TO HYPERCAPNIA AND
  POSSIBLY HYPOXIA THEREBY DECREASING VENTILATORY
  DRIVE (I.E., RESPIRATION)
• INCREASED BRADYCARDIA WHICH DECREASES MYOCARDIAL
  OXYGEN REQUIREMENTS

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PHYSIOLOGICAL PROBLEMS ASSOCIATED WITH DEEP AND
LONG DIVES
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• OXYGEN POISONING
• OCCURS WHEN PARTIAL PRESSURE OF INSPIRED OXYGEN
  EXCEEDS 570 mmHG (2.6 ATA OR 26 METERS)
• ADVERSE PULMONARY EFFECTS (EDEMA, CONGESTION,
  INFLAMMATION, ATELECTASIS (COLLAPSE OF LUNGS),
  FIBRIN FORMATION, PNEUMONIA, BRONCHITIS,
  BRONCHIECTASIS, DEGENERATION OF ALVEOLAR CELLS,
  AND SCLEROTIC CHANGES IN PULMONARY ARTERIOLES)
  BEGIN AT PIO2 OF .5 ATA OR APPROXIMATELY 22-26
  METERS
• ADVERSE CENTRAL NERVOUS SYSTEMS EFFECTS
  (TWITCHING OF FACE AND HAND MUSCLES, TETANUS IN
  MAJOR MUSCLE GROUPS, UNCONSCIOUSNESS, AND
  CONVULSIONS) BEGIN AT PIO2 OF 2.0 ATA OR
  APPROXIMATELY 90-100 METERS

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• NITROGEN NARCOSIS RESULTING FROM EXPOSURE TO
  COMPRESSED AIR
• EUPHORIA, HYPEREXCITABILITY, IMPAIRED
  INTELLECTURAL FUNCTION (PERCEPTION AND MEMORY),
  IMPAIRED NEUROMUSCULAR FUNCTION
• ALTHOUGH EFFECTS HAVE OCCURRED AT DEPTHS OF 30
  METERS, THE EFFECTS TEND TO INCREASE AS PRESSURE
  INCREASES 90 METERS HAS BEEN SET AS A PRACTICAL
  LIMIT FOR AVOIDANCE OF NITROGEN NARCOSIS

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• HIGH PRESSURE NERVOUS SYNDROME (HPNS) IS FOUND IN
  DIVES DEEPER THAN 18 ATA OR 170 METERS AND TENDS
  TO INCREASE AS THE DEPTH OF THE DIVE INCREASES
• DIZZINESS, NAUSEA, VOMITTING, BODY TREMORS,
  CHANGED EEG ACTIVITY, AND INCREASED DAYTIME SLEEP
• HPNS IS DUE TO GENERAL NEURONAL HYPEREXCITABILITY
  IN RESPONSE TO HYDROSTATIC PRESSURE AFFECTING
  NERVE CELL MEMBRANES

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• DECOMPRESSION SICKNESS RESULTS FROM NITROGEN (N2)
  ABSORPTION BY THE TISSUES OF THE BODY,
  PARTICULARLY DURING LONGER AND DEEPER (HENRYS
  LAW) DIVES
• TISSUES OF THE BODY CAN BE MORE EASILY SATURATED
  THAN DESATURATED
• HIGH PN2 RESULTS IN SUPERSATURATION OF TISSUES
  WITH N2

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• DURING DECOMPRESSION BUBBLES OF GAS ARE FORMED IN
  THE BLOOD LEADING TO DECOMPRESSION SICKNESS (THE
  BENDS) AS THE N2 SLOWING LEAVES THE BODYS
  TISSUES DURING DESATURATION
• VENOUS BUBBLES ARE NOT A MAJOR PROBLEM BUT
  ARTERIAL BUBBLES CAUSE NEUROLOGICAL SYMPTOMS SUCH
  AS SKIN RASH, MUSCLE AND JOINT DISCOMFORT,
  PARALYSIS, NUMBNESS, HEARING LOSS, VERTIGO,
  CHOCKING, CHEST PAIN, UNCONSCIOUSNESS, AND
  POSSIBLY DEATH

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DECOMPRESSION TABLES HAVE BEEN DEVELOPED BASED ON
THE DEPTH AND LENGTH OF DIVE
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• ONCE TISSUES ARE SATURATED WITH INERT GASES,
  CONTINUED EXPOSURE TO INCREASED PRESSURE WILL NOT
  INCREASE THE TIME REQUIRED FOR DESATURATION
• HENCE, DIVERS CAN STAY DOWN IN WORK HABITATS OR
  SURFACE CHAMBERS FOR LONG PERIODS TO COMPLETE
  WORK OR A MISSION AND UNDERGO DECOMPRESSION ONLY
  ONCE AT THE END OF THE MISSION

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• SATURATION EXCURSION DIVING INCREASES THE
  LIKELIHOOD OF DEVELOPING O2 POISONING IF THE
  PARTIAL PRESSURE OF INSPIRED OXYGEN (PIO2)
  EXCEEDS 0.5 ATA
• THEREFORE, THE USE OF O2 COMPRESSED AIR IN
  SATURATION DIVING VEHICLES AND HABITATS IS
  LIMITED TO DEPTHS LESS THAN ABOUT 22 METERS

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• IN SATURATION DIVING VEHICLES AND HABITATS AT
  DEPTHS GREATER THAN ABOUT 22 METERS, NITROX,
  HELIOX, AND TRIMIX BREATHING GASES ARE USED TO
  KEEP THE PIO2 BELOW .5 ATA THEREBY AVOIDING O2
  POISONING

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• WHICH MAMMAL IS CONSIDERED TO HAVE THE GREATEST
  DIVING CAPABILITIES?

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Sea Elephant?
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OR ELEPHANT SEAL?
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QUESTIONS??
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Volcanoes of the Deep Sea
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What are some of the major environmental factors
challenging the existence of life in the deep
sea?What are some of the uses of the knowledge
gained from the study of life existing in the
deeper depths of the ocean?
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CLEANING THE AIRNBC DATELINESTONE PHILLIPS
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• THE AIR IN 31 STATES AFFECTING 160 MILLION PEOPLE
  FAILS TO MEET THE FEDERAL HEALTH STANDARDS FOR
  SMOG
• FOR DECADES THE CLEAN AIR ACT HELPED IMPROVE THE
  AIR QUALITY
• 400 COAL-FIRED POWER PLANTS PROVIDING 50 OF THE
  ELECTRICITY WE USE ARE DIRTY OLD DINOSAURS AND
  THE MAJOR SOURCE OF AIR POLLUTION

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• BURNING COAL RELEASES AIR POLLUTANTS LIKE
  NITROGEN DIOXIDE (FOUND IN SMOG), SULFUR DIOXIDE
  (FORMS ACID RAIN), CARBON DIOXIDE WHICH
  CONTRIBUTES TO GLOBAL WARMING AND TOXIC MERCURY
  WHICH ENTERS OUR DIET THROUGH THE FISH WE EAT AND
  HAS BEEN LINKED TO BRAIN DAMAGE IN CHILDREN AND
  FETUSES
• PLANTS BUILT IN THE 1950s ARE STILL EMITTING AIR
  POLLUTION AT HIGH LEVELS

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• THE CLEAN AIR ACT STATES THAT IF A UTILITY PLANT
  UPGRADES TO KEEP AN AGING PLANT UP AND RUNNING,
  IT MUST ADD MODERN AND EXPENSIVE POLLUTION
  CONTROLS AS WELL
• ROUTINE MAINTENANCE, NO PROBLEM
• BUT MAJOR CHANGES WITHOUT POLLUTION CONTROLS IS
  AGAINST THE LAW

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• RECENT CHANGES IN THE ENFORCEMENT OF THE CLEAN
  AIR ACT BY THE FEDERAL ADMINISTRATION ARE NOW
  ALLOWING MAJOR CHANGES WITHOUT ADDING POLLUTION
  CONTROLS
• ITS AS IF YOU HAD A 1950 CAR AND YOU REPLACED
  THE TRANSMISSION AND THE ENGINE WITHOUT PUTTING
  ON CATALYTIC CONVERTERS

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• THIS VIDEO SEGEMENT PRESENTS THE TWO SIDES OF THE
  COIN
• COMPLETION OF MAJOR UPGRADES WITH MODERN AND
  EXPENSIVE POLLUTION CONTROLS COSTING NEARLY A
  BILLION DOLLARS BY A TAMPA UTILITY PLANT TURNS
  OUT TO BE COST EFFECTIVE
• DECREASED ENFORCEMENT OF THE CLEAN AIR ACT UNDER
  THE CURRENT FEDERAL ADMINISTRATION LEADS TO
  INCREASED RELEASE OF TOXIC POLLUTANTS BY COAL
  BURNING UTILITY PLANTS
• THOUGHTS OR CONCERNS ON THE ISSUE?

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WELL THAT ABOUT WINDS UP TONIGHTS PRESENTATION
FROM SAN JOSE SATE WHERE THE WOMEN ARE STRONG,
THE MEN ARE GOOD LOOKING, AND ALL THE PROFESSORS
ARE LONG WINDED!