REFLECTOR: Flying High

[Jim Sower]

To what extent might one expect the "serious" symptoms and impairments 
in the /absence/ of headache?  Might headache be regarded as a reliable 
warning of the onset of other impairment?

Jorge Bujanda wrote:

> Gentlemen,
>
> The headache is not the problem. What is important is what it means. 
> If you get a headache, it is likely that you have gone too high. The 
> headache is a sign of an important and fairly acute decrease of oxygen 
> delivery to the brain due to sudden decrease in barometric (oxygen) 
> pressure, due in turn to high altitude.
>
> From a neurological perspective, the onset of headache due to hypoxia 
> is proven to be accompanied by subtle and unnoticed, but increasing 
> judgment impairment, coordination loss, decreased reaction time, 
> visual impairment, drowsiness, excitement, carefree feeling, 
> overestimation of self-capabilities and exaggerated self-confidence 
> (very dangerous in the cockpit), disorientation and loss of time 
> sense. As you can see, although the most uncomfortable, the headache 
> is the least dangerous of all the events described. It has been proven 
> that there is increasing “appreciable” neurological handicap between 
> 7000 and 12000 feet and “considerable” neurological handicap between 
> 12000 and 15000 feet in physically “normal” individuals.
>
> From a cardiovascular perspective, there is an obvious decrease in the 
> oxygenation of the heart and any circulatory and cardiac problem 
> (known or unknown) will be aggravated by such decreased delivery of 
> oxygen to the heart. Any illness or factor affecting proper tissue 
> oxygenation such as anemia, hypertension, circulatory problems, heart 
> disease, emphysema (long-time smokers), asthma, and even simple things 
> such as been in the process of getting over upper respiratory 
> allergies or infections may further worsen oxygen delivery to the 
> heart and brain. This means that, under these circumstances, you might 
> not tolerate altitudes that you might have tolerated in the past under 
> “normal” conditions.
>
> More importantly, for reasons I will not detail here, any stressful 
> situation (i.e., encountering bad, or worse than expected weather and 
> climbing higher to avoid it) causes rapid and shallow breathing, as 
> well as increased tissue oxygen consumption which will further 
> decrease oxygen delivery to the heart and brain and may become the 
> last factor to precipitate catastrophe.
>
> Pay attention... borderline (high) flying does not come without risk. 
> The effects of altitude are insidious and are not something to be 
> taken lightly. A simple headache may be just a warning sign, but also, 
> a life-saving sign pointing to a bigger underlying problem.
>
> Draw your own conclusions based on what your current physical 
> condition might be (known or unknown) and the physiological facts 
> stated above.
>
> I hope this helps you increase safety awareness and I highly recommend 
> that you remind yourselves of all this as you have to take those two 
> aspirins after landing.
>
> Regards,
> Jorge Bujanda
> XL FG
> Palmdale, CA
>
> "Make your best case... not the best case."
> "Spare the noise... convince through silence."
>
>
>
>
> _______________________________________________
> To change your email address, visit 
> http://www.tvbf.org/mailman/listinfo/reflector
>
> Visit the gallery!  www.tvbf.org/gallery
> user:pw = tvbf:jamaicangoose
> Check new archives: www.tvbf.org/pipermail
> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>
>