X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 30 Nov 2008 09:20:45 -0500 Message-ID: X-Original-Return-Path: Received: from web81108.mail.mud.yahoo.com ([68.142.199.100] verified) by logan.com (CommuniGate Pro SMTP 5.2.10) with SMTP id 3323582 for lml@lancaironline.net; Sun, 30 Nov 2008 08:42:52 -0500 Received: (qmail 73520 invoked by uid 60001); 30 Nov 2008 13:42:51 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=sbcglobal.net; h=X-YMail-OSG:Received:X-Mailer:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type:Message-ID; b=Ouatp++qZLmDWeQLrGT0LPi2WdpaqJL1F6TZBmKEN/yN4X5jySDe8IcfL+YMqe9mXQURhoB1SgwQT0B+Yy4hSMDmJSn2cLXpZlDrExDdjGOVFxeLiTaHkLCZPvCWipmnEr3wlXBa7XwRONF20rchejsgxSGCJGcRARB0RoTBPDY=; X-YMail-OSG: 4BP4X5kVM1mX4PYGzMBmqi4syfqDHic9BOLYqvHiL6t6Qck_HFzaagFuEBziwuxMbOWHnt8hWWdVMp4N9t5nuANFuUOhpLoJ_csDPPdUzmNSZAspAsXOfYMUpMht6zrnPpk_jv.yfs5nqWTPa3BOm96qVy3XXJjn0hrTMX7y6DJgoQZpkZodMpY23OI- Received: from [76.229.213.187] by web81108.mail.mud.yahoo.com via HTTP; Sun, 30 Nov 2008 05:42:51 PST X-Mailer: YahooMailWebService/0.7.218.2 X-Original-Date: Sun, 30 Nov 2008 05:42:51 -0800 (PST) From: Susan Brunner Reply-To: n98pb@sbcglobal.net Subject: Re: [LML] Re: 360's at high altitudes X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-951280139-1228052571=:73413" X-Original-Message-ID: <247027.73413.qm@web81108.mail.mud.yahoo.com> --0-951280139-1228052571=:73413 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Being a person, thankfully NOT the pilot, who experiences hypoxia even at l= evels of 6000 feet, I have to agree to Scott.=A0 I was continuously experie= ncing headaches, nausea and migraines while flying in the IVP.=A0 The cabin= was in the vicinity of 6 to 7,000 feet.=A0 I now know that I read things w= hile in the plane.=A0 When my vision begins to blur, I take oxygen for abou= t 5 or 10 minutes.=A0 I have experienced hypoxia in the following order:=A0= blurred vision (not terrible, but definitely harder to focus), slight head= ache, slight nausea, tingling on the tips of my fingers (never had blue nai= ls though), and then into a massive migraine.=A0 If I let it go this far, I= am sick to my stomach for nearly two days afterward with a headache.=A0 Th= is occurred several times while flying west to east coast in a one day peri= od.=A0 Once I put it together that it was hypoxia, I take on oxygen for a 5= to 10 minute period of time, or longer to rid myself of the symptoms.=A0 I have also found that taking iron tablets for 3 days prior to flying a full= day in the IVP or even in a commercial plane have alleviated the symptoms.= =A0 Last year I had to take oxygen on a commercial flight of 4 hours with t= he same symptoms.=A0 Oxygen took care of the problem though they did want t= o have an ambulance waiting for me upon landing.=A0 Thankfully the co-pilot= had flown a IVP, got into a nice conversation with Pat and we were allowed= to depart=A0 without repercussions.=A0 We recently spent time with our dau= ghter in Colorado and the first two days were filled with some small period= s of using oxygen.=A0 I was at the hospital with my daughter and had the nu= rse check my oxygen saturation level and it was 98.=A0 I was still experien= cing the hypoxia symptoms that day and the oxygen took care of it, but the = saturation level was high.=A0=20 My feeling is that if the oxygen takes care of the problem, I use it! My 2cents. Susan Brunner PS=A0 I also have asthma. --- On Sat, 11/29/08, Sky2high@aol.com wrote: From: Sky2high@aol.com Subject: [LML] Re: 360's at high altitudes To: lml@lancaironline.net Date: Saturday, November 29, 2008, 7:08 PM =20 Well, You and other doctors may believe what you want - I am evidence that= =20 #1 below may be a normal response, but it did not happen that way=A0to=20 me.=A0 Thus, all of you abnormal pilots out there should consider the value= =20 of a pulse oximeter. =A0 Those of you flying pressurized planes should be concerned with sudden=20 decompression The rest of us have to be concerned about insidious creeping= =20 hypoxia (i.e. on a long, mid-altitudes (8000-10000) flight on a hot day).= =A0=20 Second of all, density altitude should always be considered, not MSL regard= less=20 of what the FAA says. And, I will repeat that any individual's response=A0c= an=20 vary because of physical state, fatique, age, weight, etc. =A0 See also: =A0 http://www.aeromedix.com/category-exec/parent_id/1/category_id/6/nm/Pulse_O= ximeters =A0 I have evidence that a person flying commercially at a cabin altitude of=20 8000 feet exhibited the symptoms of hypoxia after falling asleep (shallow= =20 breathing) and suffering with the anxiety of repeating her experience=20 again. =A0 You may not want to rely on an oximeter, but it's use and readings are far= =20 better than succumbing=A0to even mild hypoxia while piloting.=A0 You=20 should be able to recognize hyperventilation and stop it. =A0 Your experience may vary.=A0=20 =A0 Scott Krueger AKA Grayhawk LNC2 N92EX IO 320 SB 89/96 =A0 In a message dated 11/29/2008 6:52:16 P.M. Central Standard Time,=20 rmitch1@hughes.net writes: =20 I guess I=20 showed my obsolescence with the observation about welder=92s oxygen, as o= ne=20 person on the list stated, =93they were different twenty years ago=94, I = didn=92t=20 realize the spec=92s had changed.=20 =A0=20 However,=20 over-reliance on finger pulse oximetry is something that pilot=92s need t= o=20 understand.=A0 The reason is that pulse oximetry measures O2 saturation i= n=20 peripheral blood, which may be different from cerebral oxygen saturation,= and=20 may lag behind.=20 =A0=20 For more info=20 read the article below which appeared on our international AME list.=A0= =20 More than a few docs on the list are professors or research docs.=A0 They= =20 essentially all agree with the concepts.=20 =A0=20 Bob=20 Mitchell=20 L-320=20 Senior AME=20 =20 =A0=20 =A0=20 At the Airlines Medical=20 Directors Association scientific meeting in Orlando in 2006, Professor John Ernsting=20 presented a joint paper with Group Captain David Gradwell summarising the= =20 theoretical and experimental results of the effect of hyperventilation on= =20 arterial oxygen saturation.=A0 =20 They concluded that the=20 limitations of pulse oximetry in hypoxia should be widely recognised in= =20 aviation. Here are the reasons.=20 Reduction of alveolar PCO2=20 (partial pressure CO2)=20 to 20 mmHg when breathing air at 14k raises arterial SO2 (oxygen Saturati= on) to=20 96%, which is produced in the absence of hyperventilation by breathing ai= r at=20 1,500=20 feet.=20 A degree of=20 hyperventilation is the normal response to acute exposure of breathing ai= r at=20 or above 8,000=20 feet.=20 Using the relationship=20 between arterial PCO2, arterial SO2 and jugular venous PO2 (partial press= ure oxygen),=20 it can be calculated that when air is breathed at altitudes above 10k,=20 arterial oxygen saturation is a very poor indicator of=20 minimum=20 PO2 in the brain if the=20 individual is hyperventilating. This also applies when oxygen-air gas mix= tures=20 are breathed to avoid significant hypoxia at altitude. This is because=20 hyperventilation is known to have a very large effect on arterial SO2 in= =20 hypoxia, which is not matched by the cerebral=20 SO2.=20 Professor Ernsing's and=20 David Gradwell's paper confirmed this theoretical calculation by experime= ntal=20 study. The results showed that hyperventilation which reduced the end-tid= al=20 PCO2 produced large increases in arterial SO2 which was not matched by=20 increases in cerebral SO2.=20 The take-home message,=20 which we should share with our high-flying general aviation colleagues, c= an be=20 summarised thus:=20 =A0=20 1) Hyperventilation is a=20 normal response to any degree of hypoxia.=20 2) This hyperventilation=20 affects the peripheral arterial oxygen=20 saturation.=20 3) The result is that a=20 pulse oximeter can give misleading information about the saturation of ox= ygen=20 in the cerbral circulation. Unfortunately, it is not 'fail-safe' because = the=20 pulse oximeter may provide reassurance about satisfactory arterial SO2 wh= en in=20 fact the brain is hypoxic.=20 4) Pulse oximetry is a=20 useful tool, but its limitations in aviation must be recognised. Ideally,= an=20 oxygen-enriched gas should be breathed whenever flying above a cabin alti= tude=20 of 10,000feet. =A0 =20 =A0 Life should be easier. So should your homepage. Try the NEW AOL.com. --0-951280139-1228052571=:73413 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
Being a person, thankfully NOT the pilot, who= experiences hypoxia even at levels of 6000 feet, I have to agree to Scott.=   I was continuously experiencing headaches, nausea and migraines whil= e flying in the IVP.  The cabin was in the vicinity of 6 to 7,000 feet= .  I now know that I read things while in the plane.  When my vis= ion begins to blur, I take oxygen for about 5 or 10 minutes.  I have e= xperienced hypoxia in the following order:  blurred vision (not terrib= le, but definitely harder to focus), slight headache, slight nausea, tingli= ng on the tips of my fingers (never had blue nails though), and then into a= massive migraine.  If I let it go this far, I am sick to my stomach f= or nearly two days afterward with a headache.  This occurred several t= imes while flying west to east coast in a one day period.  Once I put = it together that it was hypoxia, I take on oxygen for a 5 to 10 minute period= of time, or longer to rid myself of the symptoms.  I have also found = that taking iron tablets for 3 days prior to flying a full day in the IVP o= r even in a commercial plane have alleviated the symptoms.  Last year = I had to take oxygen on a commercial flight of 4 hours with the same sympto= ms.  Oxygen took care of the problem though they did want to have an a= mbulance waiting for me upon landing.  Thankfully the co-pilot had flo= wn a IVP, got into a nice conversation with Pat and we were allowed to depa= rt  without repercussions.  We recently spent time with our daugh= ter in Colorado and the first two days were filled with some small periods = of using oxygen.  I was at the hospital with my daughter and had the n= urse check my oxygen saturation level and it was 98.  I was still expe= riencing the hypoxia symptoms that day and the oxygen took care of it, but the saturation level was high. 

My feeling is that if= the oxygen takes care of the problem, I use it!
My 2cents.
Susan Bru= nner

PS  I also have asthma.

--- On Sat, 11/29/08, Sk= y2high@aol.com <Sky2high@aol.com> wrote:
From: Sky2high@aol.com <Sky2high@aol.com>
Subject: [LML= ] Re: 360's at high altitudes
To: lml@lancaironline.net
Date: Saturda= y, November 29, 2008, 7:08 PM

=20
Well, You and other doctors may believe what you want - I am evidence = that=20 #1 below may be a normal response, but it did not happen that way to= =20 me.  Thus, all of you abnormal pilots out there should consider the va= lue=20 of a pulse oximeter.
 
Those of you flying pressurized planes should be concerned with sudden= =20 decompression The rest of us have to be concerned about insidious creeping= =20 hypoxia (i.e. on a long, mid-altitudes (8000-10000) flight on a hot day).&n= bsp;=20 Second of all, density altitude should always be considered, not MSL regard= less=20 of what the FAA says. And, I will repeat that any individual's response&nbs= p;can=20 vary because of physical state, fatique, age, weight, etc.
 
See also:
 
http://www.aer= omedix.com/category-exec/parent_id/1/category_id/6/nm/Pulse_Oximeters
 
I have evidence that a person flying commercially at a cabin altitude = of=20 8000 feet exhibited the symptoms of hypoxia after falling asleep (shallow= =20 breathing) and suffering with the anxiety of repeating her experience=20 again.
 
You may not want to rely on an oximeter, but it's use and readings are= far=20 better than succumbing to even mild hypoxia while piloting.  You= =20 should be able to recognize hyperventilation and stop it.
 
Your experience may vary. 
 
Scott Krueger AKA Grayhawk
LNC2 N92EX IO 320 SB 89/96
 
In a message dated 11/29/2008 6:52:16 P.M. Central Standard Time,=20 rmitch1@hughes.net writes:

 

=20

 

= =20

At the Airlines Medical= =20 Directors Association scientific meeting in Orlando in 2006, Professor John Ernsting=20 presented a joint paper with Group Captain David Gradwell summarising the= =20 theoretical and experimental results of the effect of hyperventilation on= =20 arterial oxygen saturation. 

=20

They concluded that the= =20 limitations of pulse oximetry in hypoxia should be widely recognised in= =20 aviation. Here are the reasons.

=20

Reduction of alveolar PCO= 2=20 (partial pressure CO2)= =20 to 20 mmHg when breathing air at 14k raises arterial SO2 (oxygen Saturation)<= /font> to=20 96%, which is produced in the absence of hyperventilation by breathing ai= r at=20 1,500=20 feet.

=20

A degree of=20 hyperventilation is the normal response to acute exposure of breathing ai= r at=20 or above 8,000=20 feet.

=20

Using the relationship=20 between arterial PCO2, arterial SO2 and jugular venous PO2 (partial pressure oxygen)= ,=20 it can be calculated that when air is breathed at altitudes above 10k,=20 arterial oxygen saturation is a very poor indicator of=20 minimum

=20

PO2 in the brain if the= =20 individual is hyperventilating. This also applies when oxygen-air gas mix= tures=20 are breathed to avoid significant hypoxia at altitude. This is because=20 hyperventilation is known to have a very large effect on arterial SO2 in= =20 hypoxia, which is not matched by the cerebral=20 SO2.

=20

Professor Ernsing's and= =20 David Gradwell's paper confirmed this theoretical calculation by experime= ntal=20 study. The results showed that hyperventilation which reduced the end-tid= al=20 PCO2 produced large increases in arterial SO2 which was not matched by=20 increases in cerebral SO2.

=20

The take-home message,=20 which we should share with our high-flying general aviation colleagues, c= an be=20 summarised thus:

=20

 

=20

1) Hyperventilation is a= =20 normal response to any degree of hypoxia.

=20

2) This hyperventilation= =20 affects the peripheral arterial oxygen=20 saturation.

=20

3) The result is that a= =20 pulse oximeter can give misleading information about the saturation of ox= ygen=20 in the cerbral circulation. Unfortunately, it is not 'fail-safe' because = the=20 pulse oximeter may provide reassurance about satisfactory arterial SO2 wh= en in=20 fact the brain is hypoxic.

=20

4) Pulse oximetry is a=20 useful tool, but its limitations in aviation must be recognised. Ideally,= an=20 oxygen-enriched gas should be breathed whenever flying above a cabin alti= tude=20 of 10,000feet.

 

<= /font> 



Life shou= ld be easier. So should your homepage. Try the NEW AOL.com.
--0-951280139-1228052571=:73413--