Aeromedical Transport

8/10/2019 Aeromedical Transport

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Basic Aeromedical

Transport

Presented at: ACEM Workshop

By: Sutuspun Kay Kajornboon,

M.D., Dip. Av. Med. (UK)

Director, Civil Aeromedical Center, BMC

Date: 2011


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TROPOSPHERE

Fromsealevelto FL 300-600 Dependingon temperature

Temperature Lapse Rate1.98oC / 1,000 ft.Water Vapor : Seasons & Weather,

Turbulance

Most Flying occurs

Dr. Sutuspun Kajornboon


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Physiological Division

PHYSIOLOGICAL ZONE:MSL to 10,000 ft.

PHYSIOLOGICAL DEFICIENT ZONE 10,000 ft. to 50,000 ft.

SPACE - EQUIVALENT ZONE

>50,000 ft.



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Physiological impact of decreased atmospheric

pressure

Decrease of Total Pressure

Evolved Gas Problem

*Decompression

sickness

Decrease of Atmospheric Pressure

Decrease of Partial

Pressure

Trapped Gas Problem

*Ear Barotrauma

*Sinus Barotrauma*Gastrointestinal gas

expansion

*Barodentalgia

*Etc.: pneumothorax,

peumomediastinum

Hypoxia



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mm Hg0

200 400 600 760

80k

70k

60k

40k

30k

20k10k

50k

Feet

Change of Pressure with Altitude

1/2

1/4

1/10


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Partial Pressure

Air at Sea Level

O2 = 21% pO2 = 160 mm Hg

N2 = 78% pN2 = 593 mm Hg

Other = 1% = 7 mm Hg

Total = 100% = 760 mm Hg


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Partial Pressure

Air at 10,000 ft.

O2 = 21% pO2 = 110 mm Hg

N2 = 78% pN2 = 408 mm Hg

Other=1% = 5 mm Hg

Total=100% =523 mm Hg


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Partial pressures in mm Hg at sea level

103

570

40

47

Alveolar air

Carbon dioxide

Water vapour

Oxygen

Nitrogen

160

593

Atmospheric air

Oxygen

Nitrogen

0

760

Other 7


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Alveolar Gases

10,000 ft

523 mm Hg

55O2

381N2

40

47

CO2

H2O

Sea level

760mm Hg

103O2

570N2

40

47

CO2

H2O


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Alveolar Gases

10,000 ft

523 mm Hg

55O2

381N2

40

47

CO2

H2O

Sea level

760 mm Hg

103O2

570N2

40

47

CO2

H2O

18,000 ft

380 mm Hg

Air

39O2

264N2

30

47

CO2

H2O


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Symptoms and Signs

Performance Effects

personality change

loss of judgement loss of self-criticism

euphoria

loss of short term memorymental incoordination


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Symptoms and Signs

Physical Effects

muscular incoordination

sensory loss - vision

- touch

hot flushes

cyanosishyperventilation


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Symptoms and Signs

Late Effects

semi-consciousnessunconsciousness

death


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Times of Useful Consciousness

Alt i tude TUC

FL 180 20 - 30 min

FL 220 10 minFL 250 3 - 5 min

FL 300 1 - 2 min

FL 350 30 - 60 secFL 400 15 - 30 sec

FL 430 9 - 12 sec


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Factors Affecting Tolerance to

Hypoxia - I altitude

time

rate of ascent

exercise

cold illness


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Factors Affecting Tolerance to

Hypoxia - I I fatigue

drugs and alcohol

smoking

stress and workload

physical fitness hangover


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TR PPED G S

DISORDERS


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80k

34k

18k

0

53k

4 x

1 x

10 x

Gas Expansion at Altitude


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The M iddle Ear

Eardrum

Eustachian tube

Inner earOuter ear


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Gas Expansion in

the Ear - Climb

Pressure in the

middle ear is

greater than theoutsides pressure.


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Gas Contraction in

the Ear - Descent

Pressure in the middle

ear is less than the

outsides pressure.


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Acute Baroti tis Media

Eardrum

Eustachian tube


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BAROTITIS MEDIA

An acute/chronic traumatic inflammation

caused by pressure difference between

the air in the middle ear and that of thesurrounding atmosphere.

Symptoms: pain, deafness, tinnitus and

occasionally, vertigo.


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Prevention

Equalized pressure by:

Chewing action or moving jaw side to

side

Yawning or swallowing

Valsalva

Do not fly with a cold.


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Valsalva Maneuver

Take a deep breath.

Hold the nostrils shut tight.

Tense the cheek & neck muscles.

Force pressure similar to blowing your

nose. ( Strong short burst )


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The Sinuses

Frontal sinus

Maxillary sinus

Ethmoidal sinuses

Sphenoidal sinus


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Barosinusitis Media

Signs: fullness around the eyes area to

sharp stabbing pain

: trace of blood with nasal discharge


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Treatment & Prevention

Seek treatment for URI/Sinusitis

Do a valsalva maneuver for relief

Use antihistamine nasal spray


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Intestinal Gas Expansion

Sea Level = 1.0 Liter

10,000 ft. = 1.5 Liter

30.000 ft. = 4.0 Liter

40,000 ft. = 7.0 Liter

50,000 ft. = 17.0 Liter


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Gas Expansion in

the Stomach


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Gas Expansion in

the Large Bowel


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Gas Expansion in

the Small Bowel

?


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Prevention

Avoid gas producing food.

Chew your food completely.

Avoid drinking large amount of liquid

before flight.

Start the day with good bowel habits

Avoid chewing gum during ascent


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RELIEF OF SYMPTOMS

Belching (upper GI)

Passing wind (lower GI)

Maintain level flight (for cockpit crew)

Descent to lower altitude if pain is severe

(for cockpit crew)


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Gas Expansion in the Lungs

- pneumothorax

- air embolism

- pneumomediastinum

Prevention of Trapped Gas


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Prevention of Trapped Gas

Problems

Fly only when healthy

See a doctor if ill

Equalize pressures frequently on

descent

Avoid gas producing foods, maintaina healthy diet


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Flight Environment GLARE

Strong bright light from the sun above and

reflected from the clouds below

Health effect from UVa & UVb causing

eyes irritation pterygium& cataract

(long term)

Effect pilot more than cabin crew


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Noise & Vibration


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Acceptable Noise Levels.

No NIHL with 75 -80 dB(A)exposures.

OH&S limit of 85 dB(A) for 8 hour

working day (Daily Noise Dose). Aircrew exposures regularly exceed this.


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Flight Environment

Noise

Communication

Stress

Fatigue Distraction

Deafness (hearing loss)

Vibro-acoustic Syndrome

Vibration

Pain threshold

Stress

Fatigue Motion Sickness

Speech problem

Hyperventilation

Soft tissue injury (backpain)


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Flight Environment HUMIDITY

Human are comfortable with humidityaround 60-70%; Cabin humidity could be as

low as less than 30% Can cause throat & upper airway irritation

prone to viral infection & make jet lagworse

Dryness exacerbate chronic skin problemssuch as allergy, eczema, dandruff


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HUMIDITY

Drinks more water or fluids

Avoid alcohol, too muchcoffee or tea


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Flight Environment UNUSUAL MOTION

Unexpected movements in all three axiswhich is not normally encounter on theground confusion, stress and motionsickness.

Long term worsen the effect of jet lag

and fatigue easily Turbulence are health hazard for aircrew


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Med-crew Environment

CONFINED WORKING AREA

Psychologically stressful: constantly

avoiding obstacles; worse in claustrophobia Physically a safety hazard: can get injured

easily especially during turbulence


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Thank you for your attention

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