altitude physiology
TRANSCRIPT
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ALTITUDE PHYSIOLOGY
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TERMINAL LEARNINGOBJECTIVE
• Action: Manage the physiological effects of
altitude
• Condition: While performing as an aircrewmember
• Standard: IAW AR 95-1, AR 40-8, FM 3-
04.301, Fundamentals of Aerospace Medicine
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ELO #1
• ACTION: Identify the physiological zones
and the physical divisions of theatmosphere.
• CONDITION: Given a list.
• STANDARD: IAW FM 3-04.301.
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TROPOSPHERE
Sea level to flight level 300 -600 depending on temperature,latitude and season.
Physical Divisions of the Atmosphere
STRATOSPHERE
IONOSPHERE
EXOSPHERE
MOUNT EVEREST 29,028 FEET
1200 miles
600 miles
50 miles
Tropopause
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Physiological Zones of theAtmosphere
EFFICIENT ZONE: Sea level to 10,000 feet
SPACE EQUIVALENT ZONE: 50,000 feet and above
DEFICIENT ZONE: 10,000 to 50,000 feet
18,000 ft
63,000 ft
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Composition of the Air
• 78 Percent Nitrogen N2
• 21 Percent Oxygen• 1 Percent Other
– .03 percent CO2
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ELO #2
• ACTION: Select the correct barometric
pressure at sea level.
• CONDITION: Given a list.
• STANDARD: IAW FM 3-04.301
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14.7PSI
Sea Level Pressure
Scale
lbs
760 mm Hg
OR
29.92 in. Hg
Barometer / Altimeter
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PERCENT COMPOSITION OFTHE ATMOSPHERE REMAINS
CONSTANT
BUT PRESSURE
DECREASES
WITH ALTITUDE
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SIGNIFICANT PRESSURE ALTITUDES
ALTITUDE PRESSURE
FEET mm/HG ATMOSPHERES
0 760 1
18,000 380 1/2
34,000 190 1/4
48,000 95 1/8
63,000 47 1/16
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Partial Pressure
(Dalton’s Law) 760 mm Hg
47 --- mm/Hg
95 ---190 ---
380 ---
523 ---
760 ---
21%
O2
78% N2
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The pressure exerted by a
mixture of gases is equal to the sum of the partial pressures of each gas in the mixture.
Pt = P 1 + P 2 + ...+ Pn
(Dalton’s Law)
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ELO #3
• ACTION: Identify the components of the
circulatory system that transport oxygenthroughout the human body.
• CONDITION: Given a list.
• STANDARD: IAW FM 3-04.301.
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FUNCTIONS OF THECIRCULATORY SYSTEM
• Oxygen and nutrient (fuel) transport to the cells.
• Transport of metabolic waste products to organ
removal sites.
• Assists in temperature regulation.
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Components of the Circulatory System
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Plasma
O2
Red Blood Cell
CO2
CO2 O2
CO2
O2
hemoglobin molecule
Blood transport of O2 and CO2
O2 molecule
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ELO #4
• ACTION: Select the functions and types of
respiration.
• CONDITION: Given a list.
• STANDARDS: IAW FM 3-04.301.
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FUNCTIONS OF THERESPIRATORY SYSTEM
Intake of Oxygen [O2]
Removal of Carbon Dioxide [CO2]
Maintenance of body heat balance
Maintenance of body acid base balance [pH]
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Phases of Respiration
Active Phase INHALATION
Passive Phase
EXHALATION
Breathing in Breathing out
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COMPONENTS OF THE RESPIRATORY SYSTEM
Nasal/Oral
pharynx
Trachea
Bronchi
Bronchiole
AlveolarDucts
Alveoli
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Law of Gaseous Diffusion
Gas molecules of higher pressure move in the direction of gas molecules of a lower pressure
PO2 = 100mmHg PO2 = 40mmHg
PO2 = 70 mmHg PO2 = 70 mmHg
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Blood Gas Exchange
PCO2 = 46 mm
PO2 = 100 mmPCO2 = 40 mm
PO2 = 40 mm
PO2 = 100 mm
PCO2 = 40 mmPCO2 = 46 mm
PO2 = 1 - 60 mm
Arterial Capillary
Hemoglobin Saturation 98%
O2
O2
CO2
O2
CO2
O2
Venous Capillary
Hemoglobin Saturation 75%
Tissue Alveoli
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Oxygen transport in the blood:
dependent on the partial pressure of oxygen .
pO2
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Correction of Altitude, AlveolarO2, Hb saturation
-------- ambient air --------ALTITUDE BAROMETRIC ALVEOLAR HEMOGLOBIN
(FEET) PRESSURE OXYGEN SATURATION
(mmHg) ( PAO2) % (Hb)
Sea level 760104 97
10,000 52367 90
20,000 34940 70
30,000 226
21 20
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Correction of Altitude, AlveolarO2, Hb saturation
-------- 100% Oxygen --------ALTITUDE BAROMETRIC ALVEOLAR HEMOGLOBIN
(FEET) PRESSURE OXYGEN SATURATION
(mmHg) ( PAO2) % (Hb)
Sea level 760 673 100
10,000 523 436 100
20,000 349 262 10030,000 226 139 99
40,000 141 58 87
50,000 87 16 15
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ELO #5
• ACTION: Match the type of hypoxia with
their respective causes.
• CONDITION: Given a list of hypoxia typesand a list of hypoxia causes.
• STANDARDS: IAW FM 3-04.301.
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Hypoxia
State of oxygen [O2] deficiency
in the blood cells and tissuessufficient to cause
impairment of function.
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Types of Hypoxia
• Hypemic
• Stagnant• Histotoxic
• Hypoxic
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ReducedpO2 in the lungs
(highaltitude)
Body tissue
Redblood cells
Hypoxic Hypoxia
A deficiencyin Alveolaroxygen
exchange
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An oxygendeficiency
due toreduction inthe oxygen
carryingcapacity ofthe blood+
+
+
+
++
+
++
+
+
+
+ ++
Hypemic Hypoxia
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Reduced
bloodflow
Blood
movingslowly
Adequateoxygen
Red blood cells
not replenishingtissue needsfast enough
Stagnant
Hypoxia
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Red blood cellsretain oxygen
Inability of thecell to accept or use oxygen
Poisoned tissue
Adequateoxygen
Histotoxic Hypoxia
H i S t
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Hypoxia Symptomswhat you feel
(subjective)Air hunger
Apprehension
Fatigue
Nausea
Headache
Dizziness
Denial
Hot & Cold Flashes
Euphoria
Belligerence
Blurred Vision
Numbness
Tingling
Hypoxia Signs
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• Hyperventilation
• Cyanosis
• Mental confusion
• Poor Judgment
• Lack of muscle coordination
Hypoxia Signswhat we see in you
(objective)
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Stages of Hypoxia
• Indifferent Stage
• Compensatory Stage• Disturbance Stage
• Critical Stage
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Indifferent Stage
• Altitudes:
– Air: 0 - 10,000 feet
– 100% O2: 34,000 - 39,000 feet
• Symptoms: decrease in night vision
@ 4000 feet• acuity
• color perception
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Compensatory Stage
• Altitudes:
Air: 10,000 -
15,000 feet
100% O2: 39,000 - 42,000feet
• Symptoms: impaired efficiency,drowsiness, poor judgment anddecreased coordination
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CAUTION!!!!
Failure to recognize yoursigns and symptoms may
result in an aircraft mishap.
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Disturbance Stage
• Altitudes
Air: 15,000 - 20,000 FEET
100% O2: 42,000 - 44,800 FEET
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Disturbance Stage symptoms
• Memory
• Judgment
• Reliability
• Understanding
• Coordination
• Flight Control
• Speech
• Handwriting
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Time of Oxygen
1 Minute
2 Minutes
3 Minutes
4 Minutes
5 Minutes
6 Minutes
Put Back on Oxygen
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Disturbance Stage
• Signs
– Hyperventilation
– Cyanosis
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Critical Stage
• Altitudes
Air: 20,000 feet and above
100% O2: 44,800 feet and above
• Signs: loss of consciousness,convulsions and death
F t dif i h i
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Factors modifying hypoxiasymptoms
• Pressure altitude
• Rate of ascent
• Time at altitude
• Temperature
• Physical activity
• Individual factors
• Physical fitness
• Self-imposed stresses
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keep self imposed stresses out of the aircraft
DEATH
• Drugs
• Exhaustion
• Alcohol
• Tobacco
• Hypoglycemia
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ALCOHOL
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Expected performance time for a crew member
flying in a pressurized cabin is reduced approximately one-half following
loss of pressurization suchas in a:
RD R apid D ecompression
E d P f
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FL 430 & above 9-12 seconds FL 400 15 - 20 seconds
FL 350 30 - 60 seconds
FL 300 1 - 2 minutes
FL 280 2 1/2 - 3 minutes
FL 250 3 - 5 minutes
FL 220 8 - 10 minutes
FL 180 20 - 30 minutes
Expected PerformanceTimes
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Hypoxia
• Prevention
– Limit time ataltitude
– 100% O2
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Hypoxia
• Treatment
– 100% O2
– Descend to a safealtitude
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ELO #6
• ACTION: Select the symptoms of
hyperventilation.
• CONDITION: Given a list.
• STANDARD: IAW FM 3-04.301 andFundamentals of Aerospace Medicine.
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Hyperventilation (definition)
An excessive rate and depth ofrespiration leading to the abnormal
loss of CO2
from the blood.
Hyperventilation
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Hyperventilation(causes)
• Emotional
• (fear, anxiety,apprehension)
• Pressure
breathing• Hypoxia
H til ti
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Hyperventilation Symptoms
• tingling sensations
• muscle spasms
• hot and cold sensations• visual impairment
• dizziness
• unconsciousness
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Hyperventilation reason for symptoms :
loss of carbon dioxide [CO 2 ]
shift in pH balance
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Hyperventilation
significance
• incapacitation of an otherwise outstanding, healthy air crewmember
• confusion with hypoxia
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above 10,000 feetpossible hypoxia
below 10,000 feetprobably hyperventilation
Hyperventilation
(distinguishing factors)
Hyperventilation
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Don’t Panic
Control your breathing
Check your oxygen equipment - it may be hypoxia
Hyperventilation(corrective actions)
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ELO #7
• ACTION: Select the causes and treatment
of an ear, sinus and tooth trapped gasdysbarism.
• CONDITION: Given a list.
• STANDARD: IAW FM 3-04.301.
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Dysbarism
Syndrome resulting from the effects,
excluding hypoxia, of a pressuredifferential between the ambient
barometric pressure and the
pressure of gases within the body.
B l ’ L
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Boyle’s Law
The volume of a gas isinversely proportional to its
pressure; temperature
remaining constant.
Gas E pansion
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1.8X 2.0X18,000
2.5X 25,000 3.0X
34,000 5.0X
43,000
4.0X
9.5X6.0X
Gas Expansion
G E i
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Gas Expansion
(prevention of gas pain)
• Watch your diet, don’t eat too fast • Avoid soda and large amounts of water just
prior to going to altitude
• Don’t chew gum during ascent
• Keep regular bowel habits; eat your fiber
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Opening to throatEustachiantube
External earMiddle
ear
Ear
drum
Semicircularcanal
Cochlea
Auditorynerve
Anatomy of the Ear
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Middle Ear Cavity
Eustachian Tube
AtmosphericPressure
TympanicMembrane
External Ear
Middle Ear Cavity
Eustachian TubeBlocked / Infected
TympanicMembrane
External EarAtmosphericPressure
Pressure Effect
Ear Block
Clear
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Tympanic membrane,
(ear drum),normal
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Tympanic membrane,
(ear drum),inflamed
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Tympanic
membrane,
(ear drum),infected
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Frontal
Ethmoid
MaxillarySphenoid
The Sinuses
Treatment of an Sinus/Ear
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Treatment of an Sinus/EarBlock
Stop the descent of the aircraft andattempt to clear by valsalva.
If unable to clear, climb back to altitudeuntil clear by pressure or valsalva.
Descend slowly and clear ear frequentlyduring descent.
B d t l i
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Barodontalgia
• Tooth pain due to:• Gum abscess: dull pain on ascent
• Inflamed pulp: sharp pain on
ascent
• Inflamed maxillary sinus: pain
primarily on descent
TREATMENT of
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TREATMENT of
Barodontaliga
• Descend aircraft/chamber to sea level.
• Seek dental help
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ELO #8
• ACTION: Identify the types and treatmentsof evolved gas dysbarsims, which occurswith altitude.
• CONDITIONS: Given a list.
• STANDARD: IAW FM 3-04.301 andFundamentals of Aerospace Medicine
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Decompression Sickness(evolved gas dysbarism)Results due to the reduction in
atmospheric pressure. As pressuredecreases, gases dissolved in body fluids
are released as bubbles.
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Henry’s Law
• The amount of gas
dissolved in
solution is directlyproportional to thepressure of the gas
over the solution.
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Evolved Gas Disorders
• N2 bubbles becometrapped in the joints.Onset is mild, buteventually painful!
The Bends
G
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Evolved Gas Disorders
• Paresthesia • N2 bubbles formalong nerve tracts.Tingling and itchysensation and
possibly a mottled redrash.
E l d G Di d
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Evolved Gas Disorders
• The Chokes
• N2 bubbles blocksmaller pulmonary
vessels. Burningsensation in sternum.Uncontrollable desire tocough. Sense of
suffocation ensues.
E l d G Di d
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Evolved Gas Disorders
• CNS • N2 bubbles affectspinal cord. Visualdisturbances,paralysis, one sided
tingling.
E l d f
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Evolved gas factors
• Rate of ascent
• Altitude
• Body fat content
• Age
• Exercise
• Duration of exposure
• Repeated exposure
Decompression Sickness
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Decompression Sicknessprevention
0
20
40
60
80
100
120
0 1 2 3 4 5
TIME IN HOURS
Denitrogenation
• Denitrogenation
• Maintain cabinpressurization
Decompression Sickness
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Descend
100% Oxygen
Decompression Sicknesstreatment
Land at nearestlocation wherequalified medical
assistance isavailable.
Compression greaterthan 1 atmosphere(absolute).
AR 95 1
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AR 95-1Altitude Restrictions and Oxygen Requirements
14,000
10,000
12,000
1 Hour Total30 Min Total
Unpressurized
Pressurized
10,000
14,000
25,000
Maintain Cabin PA at or below 10,000
10 Min Supply of O2 for all occupants
Crew O2 masks readily available
Supplemental Oxygen Required
AR 95-1
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AR 95-1Altitude Restrictions and Oxygen Requirements
If pressurization is lost above 14,000’, an immediate
descent will be made to a cabin pressure altitude of 10,000’
or below.
Then unpressurized restrictions apply
AR 40 8
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AR 40-8Flight Restrictions Due to Exogenous Factors
• Flying duty is prohibited for 24 hours after SCUBA diving
• Aircrew members will not be regular blood donors.
• After blood donation, aircrew members will berestricted from flying for 72 hours
• Performance of flying duty is prohibited for 12 hours after any altitude chamber flight
QUIZ
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QUIZ
Click on the link below to access the
Altitude Physiology Quiz
http://ang.quizstarpro.com
log-in and Click “Search” Tab
Class Name = Midair Collision Avoidance
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CONCLUSION