high altitude physiology and human factors october 4, 2006 audio required make sure your volume is...
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High Altitude Physiology High Altitude Physiology and Human Factorsand Human Factors
October 4, 2006
Audio required make sure your volume is tuned up!
IntroductionIntroduction
Define the atmosphere in terms of its Define the atmosphere in terms of its characteristics and human characteristics and human adaptability.adaptability.
Describe how gases in our bodies will Describe how gases in our bodies will respond to changes in the respond to changes in the environment, and how this impacts environment, and how this impacts our performance.our performance.
Review causes and hazards of Review causes and hazards of hypoxia and hyperventilationhypoxia and hyperventilation
As we ascendAs we ascend The combination of The combination of
pressure and oxygen pressure and oxygen percentage determine our percentage determine our ability to perform.ability to perform.
What altitudes do you first What altitudes do you first notice effects?notice effects?
Our environment Our environment changes…changes…• predictably,predictably,• gradually, gradually, • to the point where we are to the point where we are
in a hostile environment,in a hostile environment,• and well beyond our ability and well beyond our ability
to adapt and survive.to adapt and survive.
Hypoxic HypoxiaHypoxic Hypoxia A lack of oxygen partial pressure in the lungs or a reduction A lack of oxygen partial pressure in the lungs or a reduction
in the gas exchange area caused by:in the gas exchange area caused by:• AltitudeAltitude• DrowningDrowning• PneumoniaPneumonia• Chronic Lung DiseaseChronic Lung Disease
Location of ImpedimentLocation of Impediment• LungsLungs
Hypoxic hypoxia is the most common cause of hypoxia for Hypoxic hypoxia is the most common cause of hypoxia for a pilot due to an oxygen deficiency associated with high a pilot due to an oxygen deficiency associated with high altitude operationsaltitude operations
Effective Performance TimesEffective Performance Times
Time of Useful ConsciousnessTime of Useful ConsciousnessFL180FL180 20-30 minutes20-30 minutes
FL220FL220 8-10 minutes8-10 minutes
FL250FL250 3-5 minutes3-5 minutes
FL300FL300 1-2 minutes1-2 minutes
FL350FL350 30-60 seconds30-60 seconds
FL430FL430 9-12 seconds9-12 seconds
FL500 and FL500 and aboveabove
9-12 seconds9-12 seconds
Effective Performance Times should always be a consideration.
At 25,000 feet, the maximum altitude of the Cirrus, the time of useful consciousness is about 3-5 minutes.
It is extremely important to continually monitor the oxygen system at be prepared to deal immediately with any oxygen malfunction.
Histotoxic HypoxiaHistotoxic Hypoxia
The lack of oxygen intake into the cell (tissue The lack of oxygen intake into the cell (tissue poisoning) caused by:poisoning) caused by:• AlcoholAlcohol• NarcoticsNarcotics
Location of ImpedimentLocation of Impediment• CellsCells
Histotoxic hypoxia is dependent on factors other Histotoxic hypoxia is dependent on factors other than altitude. than altitude.
Hypemic HypoxiaHypemic Hypoxia Inability of the blood to carry oxygen caused by:Inability of the blood to carry oxygen caused by:
• Carbon Monoxide PoisoningCarbon Monoxide Poisoning SmokingSmoking Fire creates toxins that can irritate and incapacitateFire creates toxins that can irritate and incapacitate
• AnemiaAnemia
Location of ImpedimentLocation of Impediment• BloodBlood
Carbon monoxide and smoking create an oxygen Carbon monoxide and smoking create an oxygen carrying deficiency which will degrade pilot carrying deficiency which will degrade pilot performanceperformance
Stagnant HypoxiaStagnant Hypoxia Lack of proper blood distribution caused by:Lack of proper blood distribution caused by:
• ““G” forcesG” forces• Shock, fainting, etc.Shock, fainting, etc.• Heart FailureHeart Failure• Cold TemperatureCold Temperature
Location of ImpedimentLocation of Impediment• Blood Transportation ProblemBlood Transportation Problem
Steep turns at FL250 may not be a good ideaSteep turns at FL250 may not be a good idea
Subjective SymptomsSubjective Symptoms
Air HungerAir Hunger HeadacheHeadache NauseaNausea Hot & Cold FlashesHot & Cold Flashes EuphoriaEuphoria TinglingTingling ApprehensionApprehension DizzinessDizziness FatigueFatigue Blurred VisionBlurred Vision Tunnel VisionTunnel Vision NumbnessNumbness
Mental ConfusionMental Confusion Increase in rate and Increase in rate and
depth of breathingdepth of breathing CyanosisCyanosis BelligerenceBelligerence Poor JudgmentPoor Judgment Loss of muscle Loss of muscle
coordinationcoordination EuphoriaEuphoria UnconsciousnessUnconsciousness
Objective SignsObjective Signs
Factors influencing hypoxiaFactors influencing hypoxia AltitudeAltitude Individual ToleranceIndividual Tolerance Environmental Environmental
TemperatureTemperature Psychological FactorsPsychological Factors Alcohol/SmokingAlcohol/Smoking
Rate of AscentRate of Ascent Physical ActivityPhysical Activity Duration of ExposureDuration of Exposure Physical FitnessPhysical Fitness MedicationsMedications Rate of DecompressionRate of Decompression
PreventionPrevention
Use oxygen in compliance with the Use oxygen in compliance with the regulationsregulations
15,000 MSL: Crew must use Oxygen, and must be provided to each occupant
14,000 MSL: Crew must use Oxygen for flights duration
12,500 MSL: Crew must use Oxygen after 30 min
Prevention and ConsiderationsPrevention and Considerations
Use of pulse oximeterUse of pulse oximeter• Adjust the flow of oxygen Adjust the flow of oxygen
to maintain saturation to maintain saturation levels above 90%levels above 90%
Cannulas vs MasksCannulas vs Masks• Cannulas can not be used Cannulas can not be used
above FL180 as per FAR above FL180 as per FAR part 23part 23
• Remember where the Remember where the source of oxygen is from source of oxygen is from when using a cannula. when using a cannula. Eating and talking will Eating and talking will decrease the amount of decrease the amount of oxygen that is available to oxygen that is available to your lungsyour lungs
Prevention and ConsiderationsPrevention and Considerations
PassengersPassengers• Monitor passengers for Monitor passengers for
signs of hypoxia and signs of hypoxia and treat accordinglytreat accordingly
• Passengers should be Passengers should be briefed on the use of briefed on the use of oxygen during preflightoxygen during preflight
When to use start When to use start using oxygen?using oxygen?
Treatment for HypoxiaTreatment for Hypoxia Recognition of hypoxiaRecognition of hypoxia 100% Oxygen100% Oxygen Return Rate and Depth of Return Rate and Depth of
Breathing to NormalBreathing to Normal Check ConnectionsCheck Connections Check adjustment and size of Check adjustment and size of
maskmask Descend Below 10,000 feetDescend Below 10,000 feet
• Terrain permittingTerrain permitting SCREAMSCREAM
• SupplySupply• ConnectionsConnections• RegulatorRegulator• Emergency connectionEmergency connection• AdjustmentAdjustment• Mask conditionMask condition
An abnormal An abnormal increase in the rate increase in the rate and depth of and depth of breathing.breathing.
Results in exhaling Results in exhaling too much Carbon too much Carbon Dioxide.Dioxide.
VoluntaryVoluntary EmotionalEmotional
• FearFear• AnxietyAnxiety• StressStress• TensionTension
PainPain Pressure BreathingPressure Breathing HypoxiaHypoxia
HyperventilationHyperventilation
Subjective SymptomsSubjective Symptoms
DizzinessDizziness FaintnessFaintness Visual ProblemsVisual Problems TinglingTingling NauseaNausea Light HeadednessLight Headedness
Muscle TwitchingMuscle Twitching Cold, clammy skinCold, clammy skin Muscle TightnessMuscle Tightness PalenessPaleness UnconsciousnessUnconsciousness
Objective SignsObjective Signs
Hypoxic Hypoxia - Hyperventilation Hypoxic Hypoxia - Hyperventilation ComparisonComparison
SignsSigns HyperventilationHyperventilation HypoxiaHypoxia
OnsetOnset GradualGradual Varies with altitudeVaries with altitude
Muscle Muscle ActivityActivity
SpasmSpasm FlaccidFlaccid
Skin Skin AppearanceAppearance
Pale, ClammyPale, Clammy CyanosisCyanosis
TetanyTetany PresentPresent AbsentAbsent
DizzinessDizziness XX XX
EuphoriaEuphoria XX XX
FatigueFatigue XX XX
HeadacheHeadache XX XX
Poor JudgmentPoor Judgment XX XX
Light Light headinessheadiness
XX XX
TinglingTingling XX XX
Treatment for Treatment for HyperventilationHyperventilation
100% Oxygen100% Oxygen Return Rate and Return Rate and
Depth of Breathing to Depth of Breathing to NormalNormal
Check ConnectionsCheck Connections
Paper Bag MethodPaper Bag Method• Used at altitude where Used at altitude where
supplemental oxygen is supplemental oxygen is not required or needednot required or needed
Talk or sing to control Talk or sing to control the rate of breathingthe rate of breathing..
Other Physiological Affects of Other Physiological Affects of Altitude/Pressure ChangeAltitude/Pressure Change Decompression sicknessDecompression sickness
• Caused by the formation of Caused by the formation of nitrogen bubbles in the blood and nitrogen bubbles in the blood and tissues following a sudden drop in tissues following a sudden drop in the surrounding pressure, as when the surrounding pressure, as when ascending rapidly. ascending rapidly.
• Characterized by severe pains in Characterized by severe pains in the joints and chest, skin irritation, the joints and chest, skin irritation, cramps, and paralysiscramps, and paralysis
TreatmentTreatment• Decompression sickness is Decompression sickness is
a medical emergency, a medical emergency, respond appropriately.respond appropriately.
• NOTE: Time between scuba diving NOTE: Time between scuba diving on non-decompression stop dives on non-decompression stop dives and flying is 12 hours. The and flying is 12 hours. The minimum time between minimum time between decompression stop diving and decompression stop diving and flying is 24 hours.flying is 24 hours.
Other Physiological Affects of Other Physiological Affects of Altitude/Pressure ChangeAltitude/Pressure Change
Sinus/inner ear Sinus/inner ear blockageblockage• Caused by the differenceCaused by the difference in in
pressure from the middle pressure from the middle ear and the outside world, ear and the outside world, most likely due to a cold, most likely due to a cold, ear infection or a sore ear infection or a sore throat.throat.
• TreatmentTreatment On descent, level off and On descent, level off and
ValsalvaValsalva Reverse direction of Reverse direction of
pressure changepressure change Retry ValsalvaRetry Valsalva Use reduced rates of Use reduced rates of
descent and landdescent and land
The eustachian tube allows air pressure to equalize in the middle ear.
ConclusionConclusion
Remember the atmosphere that we live in is Remember the atmosphere that we live in is much different up at altitude than it is down on much different up at altitude than it is down on the surface.the surface.
As a pilot you must be prepared for any As a pilot you must be prepared for any physiological situation that may arise.physiological situation that may arise.
You must be able to recognize the symptoms of You must be able to recognize the symptoms of Hypoxia and Hyperventilation as well as be able Hypoxia and Hyperventilation as well as be able to take the appropriate action in order to prevent to take the appropriate action in order to prevent conditions from getting worse.conditions from getting worse.
Physiological TrainingPhysiological Training
UNDAF Altitude Chamber
FAA Physiological Training
Highly recommendedHighly recommended Experience conditions Experience conditions
that can lead to that can lead to hypoxiahypoxia
Learn to recognize Learn to recognize hypoxiahypoxia
Learn about other Learn about other physiological physiological limitations when flyinglimitations when flying