Human performance question

[paddywak]

A passenger breathing normally and showing symptoms similar to hypoxia at a low altitude, is likely to be suffering from:

a. hypoxia
b. fatigue
c. hyperventilation

Does anyone think the question is incorrectly worded?

The answer is c. hyperventilation according to the answer sheet

But then surely the question should read :
A passenger breathing (abnormally) and showing.........

It is possible to be hypoxic at msl and also to suffer fatigue but difficult to hyperventilate without breathing being affected.

Any thoughts?

[rjc]

You sound like you are reading too much into the question, a trap I m trying to overcome too.

Hypoxia is generally low oxygen, caused by high altitude.

Hyperventilation is low a level of CO2 in the blood, caused by rapid shallow or deep breathing. The effect of hyperventilation is, in essence, the same as hypoxia. The low CO2 changes the blood chemistry and causes physical changes in blood vessels, restricting flow and so oxygen to the brain. You won't see the blue tinges to lips and fingers without true hypoxia.

You are adding more information into the question, which states low altitude - which generally will rule out hypoxia.

The question is trying to test your knowledge of the difference between the two, and hence how do deal with each situation. Taking the question as is, and not reading extra into it is key to some of the exam questions. The CAA love this kind of stuff.

Does that help?

{others, let me know if I have this totally wrong and set paddywak on the right path!}

RJC

[GlassMan]

The list of signs and symptoms mentioned in various medical references for Hyperventilation includes the 15 symptoms listed below:

Rapid breathing
Shortness of breath
Chest pain
Weakness
Dizziness
Tingling mouth
Tingling hands
Tingling feet
Numb hands
Numb feet
Blurred vision
Racing heartbeat
Tight hand muscles
Tight foot muscles
Faintness

The first one would tend to rule out "normal breathing". I say go with "abnormal breathing".
_________________
Fixed wing spy ... But they only let me work on helicopters!

[chopperjockey]

[PilotWolf]

Whilst my previous occupation as a paramedic would also lead me not to answer hyperventilation you should be aware that someone suffering from a medical condition may not (and rarely does) exhibit all of the 'text book' signs (what you can SEE) and symptoms (what the patient is TELLING you), of the condition and in some cases none of them! In fact some one who has every symptom listed for a condition they suspect they are suffering from was usually treated with suspicion!

Hypoxia is actually insufficent oxygen supply to the (body) tissue. And can be caused by many things. We are assuming in the question, as it is flying related, that it is due to the low partial pressure at altitude. Without the question defining the type of altitude throws in more confusion - ASL or AGL? You could easily be at 500 AGL but 14500 ASL in some parts of the world. I would expect to see someone with hypoxia having some difficulty breathing too as the body tries to compensate for the lower oxygen levels (well actually it works on higher CO2 levels in most people but I don't want to confuse things even more!).

Hyperventilation is actually overbreathing (hyper- as in high) of which as a result the low CO2 (rjc mentioned), in the blood occurs.

My answer would be B. Fatigue.

W.
_________________
In memory of Skippy the Dog - "www.pilotsnpaws.org"  - RIP Scruffy.x

[chopperjockey]

[paddywak]

The paper in question was E-mailed to me by the school I am training with, they have data from previous CAA exams. I also use Air Quiz which I have found to be very helpful. Thanks for the replies, when I answered the question initially I chose (b. fatigue) as a process of elimination. I understand that they are testing knowledge between hyperventilation and hypoxia but they dont do themselves any favours. Never mind I havent taken the real paper yet so back to the books.

[rjc]

[paddywak]

It does seem to be that way rjc, I took the paper back to my school and quizzed the instructors and they all agreed it was a typo and it has now been amended to (abnormal). I took the paper yesterday for real but it has not been marked yet so fingers crossed, time to start reading the nav

[WindSwept]

[paddywak]

Yes, I agree with you there WindSwept, I have only passed three so far but they always seem to throw a couple of those in. Just got my paper back, 90% so its head down and on to the nav next.