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Those Damn Medical Guys...
by
vh5150
on 26 Feb, 2011 03:45
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I've noticed a number of physicians who post here (myself included). Think it's time to start a thread on all questions relating to medical aspects of (presumably human) spaceflight. I'm an Internal Medicine specialist (not a flight surgeon) but do perform FAA exams. Lots of potentially cool topics to discuss (like what would have happened if Mattingly had flown on Apollo 13 and actually come down with the measles!). First manned mission to Mars better have a decent medic on board, potentially capable of performing appendectomies or cholecystectomies in microgravity!
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#1
by
hop
on 26 Feb, 2011 04:30
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#2
by
telomerase99
on 26 Feb, 2011 05:40
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better to select crew who are not likely to have those kinds of issues. prophylactic abx can be used for early onset right lower quadrant pain.
also, it would probably be more cost effective to just increase the crew size to allow for a loss here or there. when you think about how much weight (cost) a ct scanner, mri, and everything else would add to the mission, when there is a good chance that it would not even be used.
for a mars landing mission however, i think that all of that equipment should definately be landed before the first crew, becuase there is a strong possibility that the ride home may not be forth coming. i hope that when we go to mars it is more of a one way trip type deal as opposed to a boots and flags mission, and if that is the case, i would want all the latest in medical technology to outfit the first martian hospital
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#3
by
vh5150
on 26 Feb, 2011 14:59
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Very small and light-weight portable ultrasound units already exist. Select groups of NASA astronauts are already being trained to utilize these and make basic diagnoses based upon the results. I know that the resolution of ultrasound is no where near as good as CT or MRI, but for long-duration spaceflights it would likely be good enough, without the mass penalty of having to launch and pre-land massive CT or MRI scanners.
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#4
by
vh5150
on 26 Feb, 2011 15:19
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A question for any flight surgeon working with NASA astronauts: how detailed are the examinations to keep the astronauts certified? I've read some reports that seem to indicate the level of astronaut fitness varies greatly. Most astronauts seem to be pretty diligent about maintaining reasonable conditioning (you don't see a lot of fat-assed Astros getting strapped-in for launch). But I've heard a few astronauts are not very diligent about maintaining conditioning (I think the quote from Mike Mullane's book was "the most exercise some of these guys get is getting up to answer the door to pay the pizza delivery guy").
Is cardiac stress testing (either nuclear or non) a regular part of their physical certification?
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#5
by
Robotbeat
on 27 Feb, 2011 17:43
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X-ray machines could potentially be small, as well.
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#6
by
hop
on 27 Feb, 2011 20:58
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#7
by
vh5150
on 01 Mar, 2011 17:42
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Actually, X-ray machines (standard radiography) are more massive and more cumbersome to utilize than portable ultrasound units, which can now mass below about 20 lbs. For what will be needed on long spaceflights, I believe ultrasound gives the biggest "bang for the buck", in terms of readily available diagnostics.
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#8
by
vh5150
on 01 Mar, 2011 17:57
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My previous question still stands. How physically fit are US astronauts compared to the general population? I suspect we would be unpleasantly enlightened to discover the reality of the situation. Most people who can endure the G forces sustained on Disney's Space Mountain or Epcot's Mission to Mars could probably tolerate the trip to LEO on the shuttle (max 3 gs). For God's sake, John Glenn, at age 77, did just fine launching on the shuttle, and I doubt that he was any exceptional physical specimen...
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#9
by
Robotbeat
on 01 Mar, 2011 18:03
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Actually, X-ray machines (standard radiography) are more massive and more cumbersome to utilize than portable ultrasound units, which can now mass below about 20 lbs. For what will be needed on long spaceflights, I believe ultrasound gives the biggest "bang for the buck", in terms of readily available diagnostics.
Quite right, but an x-ray machine doesn't
have to be huge. It can be a CCD panel with a small directional x-ray source. It can be small and portable like the units used by bomb-squads. They are can be used for detecting fractures, bone-density, a collapsed lung, blood clots (though this is complicated), etc very quickly.
And ultrasound is also very, very small. Transducers can be very small, as well.
No reason you can't have both. You could fit a whole suite of medical testing equipment (electrocardiogram, phonocardiogram, etc) in a smallish back-pack, except for MRI or CAT machines.
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#10
by
A_M_Swallow
on 01 Mar, 2011 18:11
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X-ray machines can test rocks as well as diagnose people.
X-ray machines are normally used in shield rooms. The shielding ends to be very heavy. On a planet surface distance can be used - put the patient and X-ray machine in a rover and send them for a drive. This option may not be available in a spaceship.
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#11
by
JayP
on 02 Mar, 2011 03:02
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...Epcot's Mission to Mars...
You're getting your attractions mixed up. There is no such ride. No Disney ride sustains 3Gs.
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#12
by
dks13827
on 02 Mar, 2011 03:28
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My previous question still stands. How physically fit are US astronauts compared to the general population? I suspect we would be unpleasantly enlightened to discover the reality of the situation. Most people who can endure the G forces sustained on Disney's Space Mountain or Epcot's Mission to Mars could probably tolerate the trip to LEO on the shuttle (max 3 gs). For God's sake, John Glenn, at age 77, did just fine launching on the shuttle, and I doubt that he was any exceptional physical specimen...
Glenn was very sick after landing, however, similar to a woman astronaut who fainted on her feet at the podium a few hours after landing. If this happened to one of the pilots during entry................. well, there are 2 pilots. They do worry about that.
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#13
by
CitabriaFlyer
on 02 Mar, 2011 03:35
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Great idea for a thread. I am an interventional cardiologist and an Air National Guard flight surgeon having served two tours (Baghdad and Southwest Asia.) In 1997 I did a 30 day rotation as a med student at JSC.
1) Ultrasound is awesome. You can diagnose: collapsed lung, heart attack, all kinds of abdominal and gynecological problems. MRI or CT is not practical on ISS but I have a hard time thinking of a scenario where it would change your management. There are portable xrays, but I am not sure how helpfulness would be in order to justify their mass.
2) Don't underestimate the usefulness of the physical exam. You can diagnose a lot of stuff just from examining someone. I think it was Dr. Bernard Harris who actually started trying to figure out what were normal and abnormal physical findings on physical exam.
3) As far as astronaut health is concerned they are healthier than the general population due to initial screening and they are more fit. The ones who are on active military duty have to meet PT standards (even air force PT standards require a modest amount of fitness) and most of the folks who get selected are the kind of competitive types who tend to exceed standards by a generous margin.
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#14
by
dks13827
on 02 Mar, 2011 03:43
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Great idea for a thread. I am an interventional cardiologist and an Air National Guard flight surgeon having served two tours (Baghdad and Southwest Asia.) In 1997 I did a 30 day rotation as a med student at JSC.
1) Ultrasound is awesome. You can diagnose: collapsed lung, heart attack, all kinds of abdominal and gynecological problems. MRI or CT is not practical on ISS but I have a hard time thinking of a scenario where it would change your management. There are portable xrays, but I am not sure how helpfulness would be in order to justify their mass.
2) Don't underestimate the usefulness of the physical exam. You can diagnose a lot of stuff just from examining someone. I think it was Dr. Bernard Harris who actually started trying to figure out what were normal and abnormal physical findings on physical exam.
3) As far as astronaut health is concerned they are healthier than the general population due to initial screening and they are more fit. The ones who are on active military duty have to meet PT standards (even air force PT standards require a modest amount of fitness) and most of the folks who get selected are the kind of competitive types who tend to exceed standards by a generous margin.
Citabria, are you familiar with Jim Irwin's arrythmia's on Apollo 15 ? Possibly Scott had a more minor issue, but Jim's was quite scary to the mission control Doctors.
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#15
by
CitabriaFlyer
on 03 Mar, 2011 02:22
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Most of what I know about Col Irwin's condition is from his excellent biography, To Rule the Night, and Chaikin's great read, A Man on the Moon. I will add some speculation on my part. It is my belief that Col Irwin had significant heart disease at the time of Apollo 15. The heart rhythms have been attributed to potassium depletion and dehydration which could have certainly played a signficant role. However, I believe he probably was also suffering from myocardial ischemia (insufficient blood flow to the heart muscle) due to blockage in the coronary arteries which give blood flow to the heart. I think Col Scott was the main guy trying to extract the drill that got jammed deep in the ground when they were trying to extract the core sample, but Col Irwin may have been helping. These were extremely physically demanding EVAs. Today NASA uses CT scans to screen ASCANS for heart disease. CT scans are very useful in excluding heart disease for a number of years in younger patients with a low pretest probability of heart disease. CT scans are not, in my view, that great for higher risk groups or patients who have already been diagnosed with heart disease. Having said that I think it is very possible that Col Irwin would have been found not qualified for duty when joined the astronaut corps in 1966. From my standpoint I am very glad he was able to fly the mission. Each of those twelve men has in their own unique way communicated the experience of living on the moon and I think mankind was enriched by hearing about the experience of lunar flight from the viewpoint of a deeply religeous person. I would be interested in hearing from any flight doc who was working for NASA at the time. Col Irwin was walking on the moon two weeks before I was even born.
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#16
by
vh5150
on 03 Mar, 2011 02:42
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Jim Irwin's arrhythmia (actually was frequent PVCs, premature ventricular complexes) was initially attributed to hypokalemia (low potassium blood levels), which led to John Young and Charlie Duke having to drink massive amounts of orange juice on the following Apollo 16 mission (read Chaikin's Man on the Moon for a colorful description of John Young's attributing his excessive flatulence to the potassium). Yes, Irwin's (and to a lesser extent Dave Scott's) PVCs were worrisome to the flight surgeons on duty at Mission Control. Unfortunately, Irwin's PVCs were likely indicative of underlying coronary artery disease (which ultimately killed him 20 years later), while Scott's were more likely a reflection of electrolyte imbalance (I'm not aware of Scott having subsequent coronary disease issues).
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#17
by
vh5150
on 03 Mar, 2011 02:59
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Agree, totally, Citabria, on the utility of CT scanning in the evaluation of coronary artery disease (I've never been comfortable equating a calcium score with
someone's true risk for CAD). Do you routinely do exercise stress testing on pilots with moderate to high number of risk factors for CAD? What would you need to see on said testing to "ground" somebody? Given that you're an interventional cardiologist I suspect you're performing coronary angiography on most of the abnormal stress tests you discover in those patients with moderate to high pre-test probability of having CAD (and rightfully so).
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#18
by
CitabriaFlyer
on 04 Mar, 2011 02:15
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As I mentioned NASA is using calcium scoring, which is appropriate to their population (mostly 30s) and the need for people who will be able to maintain flight status for 10-20 years.
I think (but am not sure) that the army was doing something similar for aviatiors.
The USAF was using the waiver process for antihypertensives and lipid lowering agents to eval its high risk flyers. That was proving cumbersome and so many waivers were getting approved that waivers are no longer required for BP and lipid lowering meds. So now you can be a 40 year old smoker with every cardiac risk factor except diabetes and take an F-16 into battle and pull 9Gs. This process is a pendelum. We don't want to burden our pilots and commanders with a lot of "flight surgeon horseshit" related to theoretical possible health problems but if a mishap occurs and there is even a suggestion heart disease played a role then I a suspect the screening process will be intensified.
No clue what the Navy does.
From a civilian side I do perform coronary angiograms on the majority of patients with an abnormal stress test. Sometimes, depending on the circumstannce, if the test is only mildly abnormal, watchful waiting and medical therapy may be appropriate.
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#19
by
CitabriaFlyer
on 04 Mar, 2011 02:23
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I suspect that NASA and the military's opinion on who is fit to fly into space will soon be irrelevant. I think space tourism will teach us who can and cannot safely fly into space. To start I think the only disqualifying condition will be a negative wallet biopsy. Beyond that, who should NOT participate in suborbital spaceflight?
