1

Colonel ret. Dr. med. Dipl.-Ing. H. Welsch

former Head (1993 – 2007) ofGerman

Institute of Aviation Medicine, - Division Aviation Physiology –

Königsbrück

High Altitude: Physiology and Praxis, Slovenia Sep 2009

Individual Reactions to acute Hypoxia-Symptoms of Jet Fighter

Pilots and High Altitude Parachutists

2

Gegenüberstellende Betrachtung der subjektiven Wahrnehmung von

Sauerstoffmangel-Symptomen bei Freifallspringern und Jet-Piloten

Wissenschaftliche Prüfungsarbeit zum Ersten Staatsexamen für das

Lehramt an Gymnasien

Source:

“Comparison of acute Oxygen-Deficiency-Symptoms between High Altitude Parachutists and Jet Fighter Pilots”

Nina Alexandra Gleber

im SoSe 2008

Referenten:

1. Prof. Dr. med. H.-V. Ulmer

2. Prof. Dr. M. Macsenaere

3

Hypothesis and Aim of the Study• High altitude training in a low pressure chamber is a

mandatory task in NATO for each military person who takes part in high altitude air traffic.

• It was presumed that fast jet fighter pilots, all of them full ranked officers, might react more sensitively on hypoxia symptoms than high altitude parachutists, most of them enlisted soldiers with quite a different education in military behaviour.

• The aim of the study was to compare reaction times from both groups to verify or deny the hypothesis.

4

Hypothesis and Aim of the Study• High altitude training in a low pressure chamber is a

mandatory task in NATO for each military person who takes part in high altitude air traffic.

• It was presumed that fast jet fighter pilots, all of them full ranked officers, might react more sensitively on hypoxia symptoms than high altitude parachutists, most of them enlisted soldiers with quite a different education in military behaviour.

• The aim of the study was to compare reaction times from both groups to verify or deny the hypothesis.

5

Hypothesis and Aim of the Study• High altitude training in a low pressure chamber is a

mandatory task in NATO for each military person who takes part in high altitude air traffic.

• It was presumed that fast jet fighter pilots, all of them full ranked officers, might react more sensitively on hypoxia symptoms than high altitude parachutists, most of them enlisted soldiers with quite a different education in military behaviour.

• The aim of the study was to compare reaction times from both groups to verify or deny the hypothesis.

6

Hypothesis and Aim of the Study• High altitude training in a low pressure chamber is a

mandatory task in NATO for each military person who takes part in high altitude air traffic.

• It was presumed that fast jet fighter pilots, all of them full ranked officers, might react more sensitively on hypoxia symptoms than high altitude parachutists, most of them enlisted soldiers with quite a different education in military behaviour.

• The aim of the study was to compare reaction times from both groups to verify or deny the hypothesis.

7

Simulation Centre with Human

Centrifuge and Altitude Chamber

German Air Force Institute of Aviation Medicine - Division Aviation Physiology, D-01936 Königsbrück, Germany

8

– Actual Training Devices and Areas:

– Human Centrifuge, Altitude Chamber, Anti-G-Trainer, Spatial Disorientation Device, Night Vision Training Device, Special Physical Training Equipment, Aviation Psychology (CRM)

– Actual Tasks:

– Evaluation, Training, Diagnostics, Research, Development, Test facility for industry

German Air Force Institute of Aviation Medicine

Division Aviation Physiology

9

• Altitude Physiology

•

• • Acceleration

Physiology

• Sports Physiology• (Back/Neck Training!)

• Nutrition Physiology• Aviation Psychology• Night Vision Training

Training Devices

10

• Altitude Physiology

•

• • Acceleration

Physiology

• Sports Physiology• (Back/Neck Training!)

• Nutrition Physiology• Aviation Psychology• Night Vision Training

Altitude and Hypoxia TrainingAltitude and Hypoxia Training

11

Altitude Simulation Chamber

Hypo baric + Hypoxia Training

12

Altitude Simulation Chamber Königsbrück• Max. Pressure Alt.

82.000 ft = 25.000m

• Main Chamber:– Climb-/Descend-Rate:

• +/- 20.000 ft/min

– Temperature:• +15 - +50 0C

• Decompression-chamber– Climb-/ Descend-Rate:

+/- 50.000 ft/min

– Temperature:• -50 - +10 0C

– RD: minimal 300 ms

13

14Switch „100% Oxygen“

oxygen regulator with remote control

15

ECG-MonitorPulsoxymeter

Multi-channel- Monitor

16

Pulsoxymeter

Multi-channel- Monitor

17

physiological zone

deadly zone

incomplete compensation zone

Oxygen Saturation Curve

18

Altitude Atmospheric pO²

(ft) (km) pressure (hPa) (hPa)

0 0 1013 213

3.000 0,914 908 191

7.000 2,134 782 164

10.000 3,048 697 146

12.000 3,658 645 135

15.000 4,572 572 120

18.000 5,486 506 106

20.000 6,096 466 98

22.000 6,706 428 90

25.00025.000 7,6207,620 377 377 7979

30.000 9,144 302 63

36.000 10,973 228 48

40.000 12,192 188 40

19

Time of useful consciousness at various pressure altitudesof 50 seated young med following a change from breathing oxygen to breathing air*

Time of useful consciousness (s)Altitude (ft) Altitude (m) Mean standard deviation

25.000 7.620 270 9627.000 8.230 201 4930.000 9.144 145 4534.000 10.363 84 1736.000 10.973 71 16

*Ernsting, King: Aviation Medicine Butterworths 1988

TUC: Time of Useful Consciousness

20

Altitude (ft) Altitude (m) Effective Performance Time

18.000 5.500 20 to 30 min22.000 6.700 10 min25.000 7.600 3 to 5 min28.000 8.500 2,5 to 3 min30.000 9.100 1 to 2 min35.000 10.700 0,5 to 1 min40.000 12.200 15 to 20 s43.000 13.100 9 to 12 s

*DeHart, Fundamentals of Aerospace Medicine, Lippincott Williams & Wilkins, 2002

Effective Performance Time at Altitude*

21

Objective of Training (1)

• Barometric Changes– ear drum, sinuses, trapped gases

• Pressure Breathing (>28.000 ft)– hyperventilation, breathing workload

• Acute Hypoxia (25.000 ft)– individual symptoms (at least 2!)

• Hypoxia in max. operational cabin altitude (18.000 ft): only jet fighter pilots

22

Objective of Training (2)

• Altitude Hypoxia Exposure– primarily no diagnostic/evaluation tool!– situational awareness training:

• flying in high altitude

• instrumental cross check including oxygen equipment; “PRICE”-check

• Oxygen Equipment Safety Training

• Confidence Training

23

Signs and Symptoms of Hypoxia

• Because there is always a risk of equipment failure at high altitude, early recognition of hypoxic symptoms is mandatory.

• The constellation of hypoxic symptoms and their sequence of appearance tend to be idiosyncratic to the individual.

• As a rule, the individual‘s symptoms do not change dramatically over time, but refresher training in a chamber does reacquaint the individual with the symptoms, as well as identify any change in symptoms.

24

Signs and Symptoms of Hypoxia

• Because there is always a risk of equipment failure at high altitude, early recognition of hypoxic symptoms is mandatory.

• The constellation of hypoxic symptoms and their sequence of appearance tend to be idiosyncratic to the individual.

• As a rule, the individual‘s symptoms do not change dramatically over time, but refresher training in a chamber does reacquaint the individual with the symptoms, as well as identify any change in symptoms.

25

Signs and Symptoms of Hypoxia

• Because there is always a risk of equipment failure at high altitude, early recognition of hypoxic symptoms is mandatory.

• The constellation of hypoxic symptoms and their sequence of appearance tend to be idiosyncratic to the individual.

• As a rule, the individual‘s symptoms do not change dramatically over time, but refresher training in a chamber does reacquaint the individual with the symptoms, as well as identify any change in symptoms.

26

Pilots and Parachutists

• Aircrew (Pilots and WSO): – above 8.000 ft pressure altitude in the cockpit:

additional oxygen in the breathing gas is required. Jet fighter aircraft aircrew is always equipped with oxygen breathing mask.

• High altitude parachutists: – HAHO: High Altitude, High Opening:

• Pre-breathing in the A/C, oxygen breathing in the air

– HALO: High Altitude, Low Opening• Pre-breathing in the A/C, normal breathing in the air

27

5 000

10 000

15 000

20 000

25 000

30 000

35 000

Altitude (ft)

Time(min.)

10 20 30 40 50 60 70 80 90

8 000

3 000

18 000

I

II

III

IV

V

VI4 000 ft/min

4 000 ft/min

10 000 ft/min

4 000 ft/min

2 000 ft/min

Hypoxia training:

pressure altitude 25.000 ft

28

Pilots and Parachutists

• Aircrew (Pilots and WSO): – above 8.000 ft pressure altitude in the cockpit:

additional oxygen in the breathing gas required. Jet fighter aircraft aircrew is always equipped with oxygen breathing mask.

• High altitude parachutists: – HAHO: High Altitude, High Opening:

• Pre-breathing in the A/C, oxygen breathing in the air

– HALO: High Altitude, Low Opening• Pre-breathing in the A/C, normal breathing in the air

29Zeit (min)

Höh

e (f

t)

5000

10000

15000

20000

25000

30000

35000

10 20 30 40 50 60 70 80

I

II

III

IV

V

VI4000 ft/min

2000 ft/min

4000 ft/min

2000 ft/min

10000 ft/min

10000 ft/min

Hypoxia training:

pressure altitude 25.000 ft

30

Monitoring100%

90%

75%

60%

Oxygen saturation %

Heart rate

25.000 ft18.000 ft

Breathing 21% oxygenBreathing 21% oxygen

31

objective subjective

tachypnoe hyperpnoe/dyspnoetachycardia dizziness

hyperventilation anxietycyanosis excitement

loss of interpretation feeling hot/warm/coldloss of critical faculties headache

loss of discernment drowsinessloss of consciousness euphoria/ apathia

tunnel vision

Signs and Symptoms of Hypoxia

32

Early (covert) features (signs and

symptoms) of acute hypoxia*

• Visual function:– Light intensity perceived as reduced– Visual acuity diminished in poor illumination– Light threshold increased– Peripheral vision narrowed

• Psychomotor function:– Choice reaction time impaired– Eye-hand co-ordination impaired

• Cognitive function:– Memory impaired

33

Overt features (signs and symptoms) of acute hypoxia*

• Personality Change:– Lack of insight– Loss of judgement– Loss of self-criticism– Euphoria– Loss of memory– Mental incoordination– Muscular incoordination– Sensory loss– Cyanosis

• Hyperventilation:– Dizziness– Light-headedness– Feeling of unreality– Feeling of apprehension– Neuromuscular

irritability– Paraesthesia of skin• Unconsciousness

• Death

34

Results: Pressure Altitude 25.000 ftQuestions and Answers

1. Statistic Data of Trainees

2. First Hypoxia Symptoms (Time and SaO2)

3. Duration of Breathing 21% Oxygen until Re-connection to 100% Oxygen Breathing Gas (Time and SaO2)

4. Time between first Hypoxia Symptom and Re-connection to 100% Oxygen

35

Results Pressure Altitude 25.000 ft

1. Statistic Data of Trainees

2. First Hypoxia Symptoms (Time and SaO2)

3. Duration of Breathing 21% Oxygen until Re-connection to 100% Oxygen Breathing Gas (Time and SaO2)

4. Time between first Hypoxia Symptom and Re-connection to 100% Oxygen

36

Biographic Data of TraineesJan 2005 – Nov 2006

Pilots Parachutists Σ

Trainees 265 250 515

age 21 - 57 19 - 52 19 - 57

medium age 35,1 30,3 32,8

smoker 58 (22%) 79 (32%) 137 (27%)

non-smoker 207 (78%) 171 (68%) 378 (73%)

37

Results Pressure Altitude 25.000 ft

1. Statistic Data of Trainees

2. First Hypoxia Symptoms (Time and SaO2)

3. Duration of Breathing 21% Oxygen until Re-connection to 100% Oxygen Breathing Gas (Time and SaO2)

4. Time between first Hypoxia Symptom and Re-connection to 100% Oxygen

38

First Hypoxia Symptoms

unknown 12 (5%) 9 (4%) 21 (4%)

32 - 60 s 4 (1%) 13 (5%) 17 (3%)

61 – 75 s 16 (6%) 28 (11%) 44 (9%)

76 – 90 s 52 (20%) 47 (19%) 99 (19%)

91 – 105 s 46 (17%) 40 (16%) 86 (17%)

106 – 120 s 47 (18%) 42 (17%) 89 (17%)

121 – 135 s 43 (16%) 28 (11%) 71 (14%)

136 - 240 s 45 (17%) 43 (18%) 88 (17%)

Time Pilots Parachutists Σ

39

First Hypoxia Symptoms SaO2

unknown 12 (5%) 9 (4%) 21 (4%)

99% 20 (8%) 37 (15%) 57 (11%)

90 – 99% 84 (32%) 76 (30%) 160 (31%)

80 – 89% 40 (15%) 27 (11%) 67 (13%)

75 – 79% 25 (9%) 30 (12%) 55 (11%)

70– 74% 38 (14%) 25 (10%) 63 (12%)

65 – 69% 33 (12%) 34 (14%) 67 (13%)

60 – 64% 13 (5%) 12 (5%) 25 (5%)

SaO2 Pilots Parachutists Σ

40

Results Pressure Altitude 25.000 ft

1. Statistic Data of Trainees

2. First Hypoxia Symptoms (Time and SaO2)

3. Duration of Breathing 21% Oxygen until Re-connection to 100% Oxygen Breathing Gas (Time and SaO2)

4. Time between first Hypoxia Symptom and Re-connection to 100% Oxygen

41

Time: Re-Connection to 100% Oxygen Breathing Gas

unknown 0 (0%) 0 (0%) 0 (0%)

72 - 100 s 19 (7%) 14 (6%) 33 (6%)

101 – 120 s 45 (17%) 21 (8%) 66 (13%)

121 – 150 s 110 (42%) 79 (32%) 189 (37%)

151 – 180 s 62 (23%) 86 (34%) 148 (29%)

181 – 210 s 22 (8%) 37 (15%) 59 (11%)

211 – 240 s 6 (2%) 8 (3%) 14 (3%)

241 - 322 s 1 (0%) 5 (2%) 6 (1%)

Time Pilots Parachutists Σ

42

Oxygen Saturation when re-connected to 100% Oxygen breathing gas

0

20

40

60

80

100

120

Oxygen Saturation (%)

Nu

mb

er o

f T

rain

ees

Pilots

Parachutists

99% 95% 90% 85% 80% 75% 70% 65% 60%

43

SaO2: Re-Connection to 100% Oxygen Breathing Gas

unknown 0 (0%) 6 (2%) 6 (1%)

99% 2 (1%) 1 (0%) 3 (1%)

90 – 99% 15 (6%) 14 (6%) 29 (6%)

80 – 89% 27 (10%) 18 (7%) 45 (9%)

75 – 79% 64 (24%) 20 (8%) 84 (16%)

70– 74% 99 (37%) 93 (37%) 192 (37%)

65 – 69% 56 (21%) 95 (38%) 151 (29%)

60 – 64% 2 (1%) 3 (1%) 5 (1%)

SaO2 Pilots Parachutists Σ

Most of these trainees are forced by the instructor to re-connect themselves to 100% oxygen breathing gas, when reached the 70% SaO2-level. The „after-drop“ explains the values between 60 – 70% SaO2.

44

Oxygen Saturation whenre-connected to 100% Oxygen

• 207 (78%) of 265 pilots are re-connected before their oxygen-saturation dropped beneath 70%.

• Only 146 (60%) of 244 parachutists are re-connected before their oxygen-saturation dropped beneath 70%.

45

Results Pressure Altitude 25.000 ft

1. Statistic Data of Trainees

2. First Hypoxia Symptoms (Time and SaO2)

3. Duration of Breathing 21% Oxygen until Re-connection to 100% Oxygen Breathing Gas (Time and SaO2)

4. Time between first Hypoxia Symptom and Re-connection to 100% Oxygen

46

Time between First Symptom and Re-Connection to 100% Oxygen Breathing Gas

0s 10 (4%) 6 (2%) 16 (3%)

1 - 15 s 47(18%) 21 (8%) 68 (13%)

16 – 30 s 76 (29%) 51 (20%) 127 (25%)

31 – 45 s 65 (25%) 48 (19%) 113 (22%)

46 – 60 s 31(12%) 42 (17%) 73 (14%)

61 – 120 s 22 (8%) 64 (26%) 86 (17%)

121 – 248 s 2 (1%) 9 (4%) 11 (2%)

unknown 12 (4%) 9 (4%) 21 (4%)

Time Jet-Pilots Parachutists Σ

72%

62%

47

Hypoxia Duration between first Symptom and Re-Connection to 100% Oxygen

0

5

10

15

20

25

30

0

15

30

45

60

75

90

10

5

12

0

13

5

15

0

16

5

18

0

18

1-2

40

un

kno

wn

Duration Time (s)

Nu

mb

er

of

Tra

ine

es Pilots

Parachutists265 Pilots

250 Parachutists

48

Duration of Hypoxia between first Symptom and

Re-Connection to 100% Oxygen

• 229 (91%) of 253 pilots are re-connected within the first minute (60 seconds) after recognition of their first hypoxia-symptom.

• Only 168 (70%) of 241 parachutists are re-connected within the first minute (60 seconds) after recognition of their first hypoxia-symptom.

49

Results – Smoker/Non-Smoker

Trainees Age 1. Symp. - EndTime (s) SaO2 (%) Time (s) SaO2 (%) (s)

Non-smoker 207 35,5 110,1 85,6 143,2 74,1 32,5Pilots (265) Smoker 58 34,0 110,5 84,3 144,9 74,9 35,1

mean 35,1 110,2 85,3 143,6 74,2 33,1

Non-smoker 171 30,8 109,6 86,2 157,4 72,1 47,7Parachutists (250) Smoker 79 29,5 101,3 87,9 153,1 73,2 51,8

mean 30,3 106,9 86,7 156,0 72,5 49,0

1. Symptom Reconnection

50

Results – Smoker/Non-Smoker

Trainees Age 1. Symp. - EndTime (s) SaO2 (%) Time (s) SaO2 (%) (s)

Non-smoker 207 35,5 110,1 85,6 143,2 74,1 32,5Pilots (265) Smoker 58 34,0 110,5 84,3 144,9 74,9 35,1

mean 35,1 110,2 85,3 143,6 74,2 33,1

Non-smoker 171 30,8 109,6 86,2 157,4 72,1 47,7Parachutists (250) Smoker 79 29,5 101,3 87,9 153,1 73,2 51,8

mean 30,3 106,9 86,7 156,0 72,5 49,0

1. Symptom Reconnection

MORE OR LESS: NO DIFFERENCE!

51

Summary Pilots - Parachutists

• No Differences in Type of Hypoxia Symptoms• No Differences in Recognition of first Hypoxia

Symptoms in Time and SaO2

• Pilots Re-connect themselves earlier than Parachutists (Time and SaO2) to 100% Breathing Gas

• Parachutists wait much longer after first Experience of Hypoxia Symptoms until Re-connection to 100% Breathing Gas

• There is no Difference between Smokers and Non-Smokers.

52

Summary Pilots - Parachutists

• No Differences in Type of Hypoxia Symptoms• No Differences in Recognition of first Hypoxia

Symptoms in Time and SaO2

• Pilots Re-connect themselves earlier than Parachutists (Time and SaO2) to 100% Breathing Gas

• Parachutists wait much longer after first Experience of Hypoxia Symptoms until Re-connection to 100% Breathing Gas

• There is no Difference between Smokers and Non-Smokers.

53

Summary Pilots - Parachutists

• No Differences in Type of Hypoxia Symptoms• No Differences in Recognition of first Hypoxia

Symptoms in Time and SaO2

• Pilots Re-connect themselves earlier than Parachutists (Time and SaO2) to 100% Breathing Gas

• Parachutists wait much longer after first Experience of Hypoxia Symptoms until Re-connection to 100% Breathing Gas

• There is no Difference between Smokers and Non-Smokers.

54

Summary Pilots - Parachutists

• No Differences in Type of Hypoxia Symptoms• No Differences in Recognition of first Hypoxia

Symptoms in Time and SaO2

• Pilots Re-connect themselves earlier than Parachutists (Time and SaO2) to 100% Breathing Gas

• Parachutists wait much longer after first Experience of Hypoxia Symptoms until Re-connection to 100% Breathing Gas

• There is no Difference between Smokers and Non-Smokers.

55

Summary Pilots - Parachutists

• No Differences in Type of Hypoxia Symptoms• No Differences in Recognition of first Hypoxia

Symptoms in Time and SaO2

• Pilots Re-connect earlier than Parachutists (Time and SaO2) to 100% Oxygen Breathing Gas

• Parachutists wait much longer after first Experience of Hypoxia Symptoms until Re-connection to 100% Oxygen Breathing Gas

• There is no Difference between Smokers and Non-Smokers.

56

Thank You for Patience and Listening!

Questions?

57

Incidence of Decompression Sickness (DCS) and Venous Gas Emboli (VGE) staying in high altitude;

without pre-breathing(Andrew A. Pilmanis, Ph.D.)

0

10

20

30

40

50

60

70

80

90

100

11 13 15 17 19 21 23 25

Höhe, ft X 1000

% V

ork

omm

en

VGE

DCS