Just Plain Ruff Posted October 12, 2010 Posted October 12, 2010 About 6 months ago I spent some time at Christiana Care Hospital in Delaware. I spent 9 days working with a Prison transport medic who flew on the planes like in the movie Con-air. He said he has taken care of some really sick prisoners. He said that the worst patients were the patients who were stroking. I don't know the dynamics of altitude on strokes. He said that a hemmorhagic(sic) would get much worse on the descent than at altitude. He tried to explain it to me but it didn't make much sense. Can someone help me out here? Flight medics let me know. PS - if anyone wants to work for Con-air let me know, I can put you in touch with this guy.
uglyEMT Posted October 12, 2010 Posted October 12, 2010 Ruff I am not a flight medic but I think I can laymen term out the reasoning. Pressure plain and simple. Ever been on a comercial aircraft and they didnt equalize the pressure just right and it felt as though someone was squeezing your head? Well now picture if there is a bleed in the brain, the increased intercranial pressure is causeing the bleed to get worse. You dont see the pressure thing as much on acent because your going from higher to lower atmosphieric pressures thus requiring the plain to add pressure to the cabin, so on the decent this added air pressure is what causes the increase. I know its not medical or basically anything more then what i know about air travel but I hope it helps. I will try to find some medical literature to back up my statment.
Just Plain Ruff Posted October 12, 2010 Author Posted October 12, 2010 ugly, that's basically what he told me but it just didn't sink in. I'd like to find out where I could get some of that literature as I'm thinking of applying to work at his agency. I'd like to be prepared. He is not completely sure if they are allowing just paramedics rather than paramedic/nurses apply. He is checking into it for me.
tniuqs Posted October 12, 2010 Posted October 12, 2010 (edited) About 6 months ago I spent some time at Christiana Care Hospital in Delaware. I spent 9 days working with a Prison transport medic who flew on the planes like in the movie Con-air. He said he has taken care of some really sick prisoners. He said that the worst patients were the patients who were stroking. I don't know the dynamics of altitude on strokes. He said that a hemmorhagic(sic) would get much worse on the descent than at altitude. He tried to explain it to me but it didn't make much sense. Can someone help me out here? Flight medics let me know. PS - if anyone wants to work for Con-air let me know, I can put you in touch with this guy. Firstly: 1- Were these "patients / prisoner's " actively having CVA during a flight ? 2- Were the events due to the flight or did they have a history of CVA, TIA or uncontrolled HTN ? 3- Was the aircraft pressurized ? Ok late edit you said @ 40000 .. what type aircraft are they using ... a Lear ? thats kinda high for most aircraft used .. The movie Con Air, (unpressurized tramp WW2 transport) but got to love Cage, Malkovich, +++ Star filled "fiction action movie" but the best was Steve Buscemi ... he played a great evil sicko. A couple of links for physiology in relation to Boyle's Law, (the most likely the culprit) Hypoxia at altitude and the ODC shift at altitude. With the increase incidents of DVT leading to CVA / PE with stagnation of venous blood flow while sitting for long periods ... hope that helps, well a bit. http://www.cfpc.ca/cfp/2004/jan/vol50-jan-cme-3.asp http://books.google.ca/books?id=kLW-kIphsnwC&pg=PA47&lpg=PA47&dq=flight+physiology+in+stroke&source=bl&ots=8foHjipf03&sig=XO5obEuwFnIoGN0qhSiiinf5Sdo&hl=en&ei=D6W0TIm1OsqbnAeBwNX-BA&sa=X&oi=book_result&ct=result&resnum=6&ved=0CDMQ6AEwBQ#v=onepage&q=flight%20physiology%20in%20stroke&f=false In passing and just anecdotal, this also has been my experience as well, for some curious reason with critical patients decide to "crash" when are on descent from altitude, although seizures in my experience are more much more "popular" on take off, (G forces and Noxious Stimuli) I highly suspect. cheers Edited October 12, 2010 by tniuqs
Just Plain Ruff Posted October 12, 2010 Author Posted October 12, 2010 1- Were these "patients / prisoner's " actively having CVA during a flight ? From what he told me they were actively having a CVA in flight. 2- Were the events due to the flight or did they have a history of CVA, TIA or uncontrolled HTN ? He did not tell me their history. 3- Was the aircraft pressurized ? Ok late edit you said @ 40000 .. what type aircraft are they using ... a Lear ? thats kinda high for most aircraft used .. 40000 was just a number. I don't know how high they were but the jets they use are mainly 737's. His transport service which is contracted by the US Bureau of Prisons transports people who have been either deported due to crimes or have been convicted of crimes in the US and an arrangement between the US government and their home of origin to send them back to face many additional charges. The stories he tells. In one country when the men get off the plane they are separated out - 1 group goes to a waiting bus and the next group goes to a waiting military/paramilitary vehicle and those are the ones who know what will happen to them. He said some of those going to the military type vehicle are never heard from again. He left it up to me to make my own assumption as to what happens to them but he said that whatever I was thinking was more than likely correct.
ERDoc Posted October 13, 2010 Posted October 13, 2010 I doubt you'll find much as it is pretty difficult to do a study on something like this. As for the pressure differences, I'd have to disagree. The brain is a closed system so any pressure effects will not be directly felt by the brain. In order for the brain to be affected by the pressure change, that change would have to be transmitted through (and result in deformity) of the skull. The reason you feel the pressure differences during ascent and descent in an aircraft is due to pressure differences in the middle ear (behind the ear drum) and sinuses if yours are clogged. These spaces do not directly communicate with the intracranial vault. It sounds more like anecdotal evidence than a true relationship to me. Why don't we seem more strokes on commercial aircraft if the pressure was causing the problems?
uglyEMT Posted October 13, 2010 Posted October 13, 2010 (edited) Ruff while researching for a different threa I came across this. http://www.hkcem.com/html/publications/Journal/2003-3/p191-196.pdf The cabin pressure in commercial aircraft is adjusted to the equivalent of barometric pressure at the altitude of 1,500 to 2,500 meters (5,000 to 8,000 feet) above sea level. At these pressures, there will be a reduction of the partial pressure of arterial oxygen from 95 to about 56 mm Hg in healthy individuals. This represents a 4% reduction in the oxygen carrying capacity. The arterial partial pressure of oxygen can be maintained to a certain extent by hyperventilation. Altitude is particularly poorly tolerated by patients with pre-existing hypoxia. Pressurization of the internal environment of the aircraft increases the total air pressure, thereby increasing the inspired as well as alveolar partial pressure of oxygen.9 As a result of the decreased pressure, air and gas in body cavities expand, as described by Boyle's Law (volume of gas varies inversely with pressure). This can manifest in a variety of ways as the trapped gas expands. (Table 1) The low humidity, usually in the range of 10-20%, may cause discomfort in some passengers, with symptoms such as dry eyes, dry nasal mucosa and exacerbation of reactive airway disease While ascending through the first 9,000 to 18,300 meters (30,000 to 60,000 feet), the external temperature decreases in a linear fashion, at an average of 2 degrees Celsius (3.6 degrees Fahrenheit) per 305 meters (1,000 feet).9 From reading that passage Ruff looks like it more do to expantion which thus can cause increased pressures. Old Boyle's Law Edited October 13, 2010 by UGLyEMT
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