The document discusses the effects of cabin pressure on passengers during air travel. It notes that the cabin is pressurized to an altitude of 1524-2438 meters, resulting in lower oxygen levels compared to sea level. For most healthy passengers this causes a decrease in arterial oxygen tension. However, for passengers with pre-existing lung conditions, it can cause oxygen saturation levels to drop significantly. The document also reviews guidelines for oxygen use during flights and studies examining passenger discomfort at different cabin altitudes.

1. Efectul presiunii barometrice
asupra pasagerilor din cabina de zbor
Andreea MARZA
Alexandru HORAICU
Medici rezidenti Pneumologie

2. Ce vom
discuta?
Statistici
Fiziopatologie
Guidelines
Studii
Concluzii

3. Statistici
1M
People are traveling by air at
any given time
700M
Americans travel by air in the
US
1/10-40K
Passengers will experience
an medical emergency.

4. Statistici
>50%of passengers age 50
or over have at least
one health issue(s)
VARSTA INDICENTA
Emergencies will become more
frequent as % of elderly increase

5. In the Air, Health
Emergencies
rise quietly
Flights are going farther and lasting
longer. Av. length of a flight in 2000:
1,233 mi
Av. length of a flight in 2006: 1,347
mi
Max flying time today: 20 hrs

6. Fiziopatologie

7. Atmospheric Composition
The atmosphere is made up of oxygen, nitrogen,
and smaller amounts of other gases.
The percentage of these gases is fairly constant
in the atmosphere up to an altitude of 70,000
feet.
What is of concern are changes in pressure and
temperature of the air during ascent. These two
factors are the cause of all physiological
problems encountered by pilots.
78% nitrogen
21% oxygen
1% other
up to
70,000 feet

8. What is Altitude Illness?

9. What is Altitude Illness?

10. The passenger cabin is pressurised to
1524—2438 m. This reduced pressure
within the passenger cabin results in
lower syst. PaO2 and oxyhaemoglobin
(oyx-hb).
For most healthy passengers, this results
in a decrease in the arterial partial
pressure oxygen tension.
Silverman D, Gendeau M: Medical issues associated with
commercial flights. The Lancet 2009; 373/9680: 2067-77

11. Passengers with pre-existing lower sea-
level oxy-hb sat have greater declines
during flight.
E.g., a passenger with mild COPD with a
sea-level PaO2 of 70 mm Hg PaO2 to
about 53 mm Hg or oxy-hb sat of
approximately 84% at a cabin altitude of
2438 m
Silverman D, Gendeau M: Medical issues associated with
commercial flights. The Lancet 2009; 373/9680: 2067-77

13. In-Flight Medical Emergencies. A Practical
Guide to Preparedness and Response

14. Guidelines ➔ Double the flow rate in flight
➔ The maximum oxygen deliverable by most
POCs and commercial aircraft is
approximately 3 and 4 LPM, respectively
➔ Therefore an oxygen requirement greater
than 3-4 LPM at sea level may preclude
travel by air.

15. Effect of Aircraft-Cabin Altitude on
Passenger Discomfort
The frequency of reported complaints associated with acute mountain sickness (fatigue,
lightheadedness and nausea) increased with increasing altitude and peaked at 2438 m.
Most symptoms became apparent after 3-9 hrs of exposure.
Muhm JM et al. N Engl J Med 2007; 357: 18-27

17. 1
One study of 8 flights in Airbus A380
aircraft found a median cabin pressure
altitude of 6128 feet (1868 m), and 65
flights in Boeing 747-400 aircraft found
a median cabin pressure altitude of
5159 feet (1572 m).
The Ernivest SJ30 business jet can
provide a sea-level cabin altitude
pressure when cruising at 41000 feet
(12000 m).

18. How do high altitude populations avoid
hypoxia?

20. How have these adaptations arisen?
Aceste mutații în EPAS1, la o frecvență mai
mare la tibetani decât la vecinii lor din Han, se
corelează cu scăderea concentrațiilor de
hemoglobină în rândul tibetanilor

21. How have these adaptations arisen?
O altă genă, EGLN1, care reduce producția de
hemoglobină atunci când oxigenul este
abundent, prezintă, de asemenea, modele
genetice de variație în concordanță cu selecția
în ambele Tibetani și Andeeni

27. Concluzii
➔ Analiza functionala a genelor EGLN1 si EPAS1 care sunt asociate cu nivelurile
crescute de Hb in acest esantion tibetan va spori in continuare intelegerea
noastra legata de adaptarea genetica la altitudine mare.
➔ In plus, vom intelege mai bine raspunsul uman la hipoxie, care are implicatii
importante pentru prevenirea si tratamentul “bolii de munte”, edemului
pulmonar si edemului cerebral la altitudine.

28. References
1. University of Washington. “Genome-wide Insights Into Patterns Of The World’s Human Population Structures.”
ScienceDaily, 14 May 2009. Web. 17 Jun. 2012.
2. Mayell, Hillary. “Three High-Altitude Peoples, Three Adaptations to Thin Air,” National Geographic News. 2004
3. Beall, Cynthia. “Two routes to functional adaptation: Tibetan and Andean high-altitude natives” PNAS, 104:suppl1. 2007.
4. Storz. “Genes for High Altitudes” Science, Perspectives, 329. 2010.
5. Lerner, Evan. “Penn Researchers Help Solve Questions About Ethiopians’ High-Altitude Adaptations,” Penn News. 2012.

29. References
6. Sanders, Robert. “Tibetans adapted to high altitude in less than 3,000 years,” UC Berkeley News Center. 2010.
7. Khan, Razib. “Why Tibetans breathe so easy high up,” Discover Magazine. 2010.
8. Fisher, Max. “Why Kenyans Make Such Great Runners: A Story of Genes and Cultures,” The Atlantic Monthly. 2012.