Splatter, Puny Humans and Space Surgery

Most shows in space suffer from some fundamental flaws. The monochromatic fashion choices. The humanoid template of 98% of interplanetary lifeforms. The flexible relationship with physics. One of the things that bugs me is the lack of focus on the mundane stuff. I never see anyone in orbit clipping their toenails. There’s always some multi-hearted warrior alien in the way of the boring.

The bit that I struggle the most with is the fact that everyone is just walking around like gravity is still in charge. Shouldn’t everyone be pulling the big somersaults in mid-air as they talk over the latest threat to internationally coordinated space uniforms?  How could you possibly create a miniature pocket of Earth-equivalent gravity? (My pondering here may be a result of my ignorance on the topic of miniature gravity pockets.)

Nowhere is this more apparent than in the deep space practice of medicine. The reality of medicine doesn’t include ‘Tricorder’ electronic reiki devices or holograms acting as medical professionals. It is a much trickier problem that is scrabbling for good solutions in an age where we’re inching ever closer to spending long periods orbiting or heading off to Mars. Once you include people in a situation, you guarantee periods of ill health or fortune. And mostly not big dramatic accidents. Ingrown toenails, styes and mouth ulcers will crop up. Cancer too.

Just recently there’s been a few stories describing different approaches to solving the problems of surgery in space. Unsurprisingly, the anaesthetic isn’t mentioned in all of the focus on the technology of doing the surgery. Unless the aim is to make any space surgery as traumatic as giving unwelcome birth to alien spawn, then the anaesthetic bit is worth a look to round out the story.

 

Can’t we just make illness take a break?

Well, no. NASA estimates it takes about 68 months of combined person time before you’ll need emergency evacuation. It’ll take at least 7 months to get out to Mars. We’ve already seen examples of self-surgery on the frontier before (see here and here). Disease doesn’t tend to respect our life plans. We’ll just be adding the challenge of weightlessness.

As you’d expect our bodies are more adapted to the experience of gravity than the absence of it. Leaving its steadying hand induces changes in every body system in ways designed to trip up the naive anaesthetist. As a first example part of the lining of all your blood vessels, the endothelium, functions differently. This changes the normal maintenance of blood pressure and the balance of substances passing out into the tissues. Kidney impairment can result from associated changes in blood flow.

It doesn’t stop there. There is a shift of the fluid in your body so that your head is actually more ‘wet’. The heart of an astronaut decreases in muscle mass and becomes more spherical. This contributes to heart dysfunction, particularly in the phase of the cardiac cycle where the heart is relaxing. There’s also some evidence of heart rhythm disturbances and development of coronary artery disease. Your blood volume decreases and specifically has less red blood cells available to carry around oxygen. Your respiratory system actually does pretty well out of it, although some congestion of the  nasal passage might occur (all that fluid).

For the budding space anaesthetist there’s also alterations in the way the body interacts with drugs. This is not only due to changes in metabolism and clearance from the liver and kidneys. The receptors on which some drugs act will also change in number and sensitivity. That all adds up to lots of adaptations for the medico, and we haven’t even got to the practicalities of the surgery.

Blood is Thicker than Water

Many of the demonstrations so far for surgical techniques in space have occurred while undertaking brief weightless flight in very high planes (those undertaking parabolic flight arcs). There has already been demonstrations of keyhole surgery in zero gravity although the organs floating buoyantly around inside the abdomen can be a little obstructive.

The other challenge that immediately comes to mind is what happens if there is bleeding? If you need to visualise that a little more,  consider this demonstration of the behaviour of fluids in space by Commander Chris Hadfield. Now imagine you’re not dealing with a little floating globule of water. Imagine there’s arterial blood spurting out under pressure and you’re trying to operate. It won’t be long before the space you’re working in looks like you handed a toddler a particularly gruesome paint gun. Quite apart from the blobs of blood floating in front of you. It would be enough to make a blood splatter expert combust.

Solving this problem has driven a variety of responses. One previous attempt involved effectively placing a clear box over the patient – but it didn’t take long for that to turn into a monochromatic blood-hued box. More recently a team described the use of domes that would get laid over a bleeding area then filled with fluid to provide hydrostatic compression. Such a system has already been tested and appears to offer an early prototype to help control bleeding while modifications should allow ongoing operating.

An alternative approach is to use the assistance of robots such as  this prototype that would be released inside the patient and work away on the inside. Testing of this system is not that far away. Of course, the greatest technology we have will still need someone to do the driving and that’s part of what makes things interesting.

Many skills are needed to be an astronaut. [via http://www.themirror.co.uk]

The Right Stuff

Who will you call when faced with an angry appendix 4 months out into space? There’s two obvious options – train medical types to become astronauts or train astronauts to pick up scalpels. The latter seems to be the current approach for missions heading way out there (although I’m not sure I’d expect much given the description for the Mars One program). Part of the idea here might be to support the initial training by communication with experts on the ground. Unfortunately for emergencies there’s a bit of a communication lag (up to 22 minutes one way for a chat) and I’m not sure WhatsApp is likely to take off as a surgical trainer any time soon.

So maybe the more sensible thing is to look for people from medicine who might meet the profile of someone who’d be useful in space. Maybe someone with training in a critical care specialty. Or who has some experience in doing medicine in unusual or difficult environments. Or even mid-flight.

It’s all the sort of mundane stuff that is actually more interesting than phasers at 12 paces. It’s even inspired me to order a new shirt.

Coming soon to a shirt and life plan near me. [via snorgtees.com]

After a bit more reading?

One of the better recent reviews I found came out of South Africa:

Van der Walt J, Ernst AH. The anaesthetic management of microgravity-exposed individuals. South Afr J Anaesth Analg 2013;19(5):243-7.