Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CVR > Lungs At Altitude > Flashcards

Lungs At Altitude Flashcards

1
Q

How is the death zone defined

A

Over 8000 m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Sea level

A

Altitude = 0m
Atmospheric pressure = 100KPa
PiO2 = 0.20 x 100KPa = 20KPa

[PiGas = FiGas x Patm]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Sea level normal blood gases

A

PaO2 10.5 - 13.5 KPa
PaCO2 4.5 - 6.0 KPa
pH 7.36 - 7.44

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Sea level normal PaO2

A

10.5-13.5 KPa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Sea level normal PaCO2

A

4.5-6.0 KPa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Sea level normal pH

A

7.36-7.44

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Right shift oxygen dissociation curve due to

A

Acidity
2,3 DPG*
Increased temperature
Increased PCO2

[*2,3 biphosphoglycerate]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

FiO2 does what with altitude

A

Remains constant at approx 0.21

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

PiO2 does what with altitude

A

Falls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Lungs at altitude- normal response

A

Hypoxia leads to..
Hyperventilation at 10000ft altitude
Increases minute ventilation
Lowers PaCO2
Alkalosis initially
Tachycardia
Adaptive changes
Multiple
Alkalosis compensated by renal bicarbonate excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Barometric pressure at an altitude of 0m

A

101 KPa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Barometric pressure at an altitude of 4800m

A

57 KPa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Barometric pressure at an altitude of 6300m

A

46 KPa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Barometric pressure at an altitude of 8100m

A

37.5 KPa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Barometric pressure at an altitude of 8848m

A

33.5 KPa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

A-aDO2- alveolar arterial O2 difference

A

Whilst normal pretty complete equilibration of O2, there normally is a small difference between Alveolar and arterial oxygen partial pressure

= PAO2 – PaO2 = (approx) 1KPa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

PAO2 =

A

PiO2 - PaCO2/R

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

PaO2 =

A

PAO2 - (A-aDO2)

19
Q

Adaptive changes of lungs at altitude

A

Multiple
Alkalosis compensated by renal bicarbonate excretion

20
Q

Hyperventilation at 10000ft altitude

A

Increases minute ventilation
Lowers PaCO2
Alkalosis initially
Tachycardia

21
Q

High altitude illness examples

A

Acute mountain sickness
High altitude pulmonary oedema (HAPE)
High altitude cerebral oedema (HACE)

22
Q

Why does oxygen dissociation curve shift to the right

A

Shifts to right to give off more oxygen because areas which are more metabolically active have a higher CO2 concentration and lower pH

23
Q

Acute mountain sickness

A

Recent ascent to over 2500m
Lake Louise score >/= 3
Must have a headache and one other symptom

24
Q

Ascending…

A

PiO2 falls
Decreased PAO2
decreased PaO2
Peripheral chemoreceptors fire (eg carotid)
Activates increased ventilation (Va), reducing PaCO2
Increased PAO2
increase PaO2

25
Q

Hyperventilation

A

PaCO2 DROPS
PaO2 REMAINS HIGHER

26
Q

Alveolar oxygen tension as you go higher

A

Linear drop in PaO2

27
Q

Treatment of acute mountain sickness

A

Can only be reliably treated by descent

[o2, recompress, acetazolamide]

28
Q

Blood gases at height

A

Lower PaO2
Lower PaCO2
Higher end of pH (alkalosis)

29
Q

At risk of acute mountain sickness if

A

Recent travel to over 2500m, after a few hours
Sea level normal dwelling
Altitude, rate of ascent and previous history of AMS
Younger people

30
Q

Respiratory quotient

A

0.8

31
Q

High altitude pulmonary oedema

A

Unacclimatised individuals
Cough, shortness of breath
Rapid ascent above 8000ft (2438m)
2-5 days
-Risk less if sleeping below 6000ft (1829m)
-Speed of ascent slower (300-350m/day)
-Individual susceptibility
-Exercise
-Respiratory Tract Infection
Incidence 2% at 4000m

32
Q

Treatment of high altitude pulmonary oedema

A

O2
Decent urgent
Gamow bag
Steroids
Ca2+ blockers?
Sildenafil

33
Q

High altitude cerebral oedema

A

Serious
AMS not a pre requisite
Confusion
Behaviour change
Immediate descent
Symptoms may resolve relatively quickly

34
Q

Treatment of high altitude cerebral oedema

A

Immediate descent
Gamow bag

35
Q

Who should avoid flying

A

Pneumothorax
-Not with a closed pneumothorax

Infectious TB
Major haemoptysis
Very high oxygen requirements at sea level
-> 4L/minute

36
Q

High altitude pulmonary oedema cause

A

Pulmonary capillaries become leaky

37
Q

Effective cabin atmosphere

A

1890m

38
Q

Cabin pressure

A

81 KPa

39
Q

Atmospheric pressure at altitude of 10000m

A

21 KPa

40
Q

If SpO2 is low, what must happen before flying
<95%

A

Physiological test eg hypoxic test

41
Q

Hypoxic hypoxia

A

Low PaO2 due to high altitude
Above 10000ft

42
Q

Symptoms of HAPE

A

Cough
Frothy sputum
Breathlessness
Chest pain

43
Q

Symptoms of HACE

A

Confusion
Ataxia

CVR (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions