Day 3 count:
– “7, 7 operations done, ah, ah, ah.” (Actually I can’t maintain that nod to Count von Count.)
– 6 coffees. Probably only 6.
– 1 AC/DC playlist deployed.
Those 7 operations include a range of things that need fixing. From blood vessels that should have closed themselves to ones that should be wider and lots of holes in hearts that need patching. With a bit of good planning and a room full of gear you can get plenty done and, more importantly, we don’t need to think about scuba diving in the process.
Wait, I should probably explain the scuba diving comment.
Imagine for a second you’re given the job of closing up a hole between the ventricles of the heart. The ventricles are the larger chambers with the job of pushing blood out to the body – the right ventricle sends blood out to the lungs to pick up oxygen that you’ve breathed in while the left ventricle sends it out to all the other bits of your body.
In some people those two big chambers don’t entirely divide off like the standard blueprint and blood can jet across that hole. It’s not a big deal for most immediately. If you leave it though, it can cause issues. So sometimes a patch to close that hole is needed. That’s sometimes where surgery can come in.
If you stop and think about the challenges of operating on the heart, a couple of things are obvious. The heart gets visited by all the blood the body has. You have to get inside those chambers to work on it but having blood everywhere might not help with the sewing. And spilling blood everywhere while you sew might not be productive.
So let’s say you plan to operate without the blood pumping around. What next? How does the oxygen the organs need get there?
The Big Chamber
Before the machines we use now, there was diving. When you go 10 metres below the surface of the water, you add a whole atmosphere of pressure of the gases you breathe. Delivering pressurised gases is a big part of SCUBA diving. If you don’t have water to dive into to get your pressurised gas, you can use a very particular kind of chamber. A hyperbaric chamber.
When you exploit the extra pressure from a hyperbaric chamber in medicine, it’s a bit like you’re cramming all the oxygen from extra atmospheres into the patient’s blood. You can supersaturate the patient with oxygen.
It’s not that long ago that it was suggested that putting patients inside a hyperbaric chamber with an interested surgical team might be a way to lengthen the amount of time you could do surgery on a heart removed from all flow of blood around the body. Those extra few minutes might just buy you the time to do a more complex heart operation.
One Small Problem
There was one little thing getting in the way. It wasn’t even the cost. It was the occasional explosion.
Add the smallest ignition to an environment that already has massive amounts of oxygen and things that can burn and you can start a very nasty fire. From 1923 to 1996 there were 39 reported fires in hyperbaric chambers and 25 of those occurred where clinical work looking after patients was happening.
24 of those clinical fires happened between 1967 and 1996. 60 people died. On at least one occasion, not only did the patient inside the chamber die from their burns, the ends of the chamber exploded outward from the rapid rise in pressure inside the chamber. The patient’s wife was killed by the flying debris.
It was one factor that pushed people away from hyperbaric chambers. The thought of losing whole surgical teams was probably a bit of a worry.
So if you can’t use compressed gas, how much space do you need to replace a kid’s little heart?
Different Wheels of Steel
One of the members of the team is here to drive the wheels of steel. (He’s not a DJ. In fact the thought of him being a DJ is pretty disconcerting.)
When you come on an aid trip to do open heart surgery, you need to pack one of these devices.
This is the cardiopulmonary bypass machine. While it has to do some clever things like cool and heat circulating blood and deliver doses of medicine to stop the heart it has one big job. It has to take over the job of the heart in making blood flow around the body to carry oxygen. For the time that the heart is open and having things fixed, this takes over.
The perfusionist who makes it work is an extremely well trained part of the team. The machine, with all that tubing and so many roller pumps, is what is required to do the work of the heart inside of the patient (even a 5 kg child).
All that to do the job of the heart. It doesn’t even pick up satellite TV.
It’s also just one part of what you need to take to do open heart surgery in another country. Just in case it wasn’t clear that mounting an aid trip to do heart surgery overseas wasn’t a fair bit of effort.
Of course it’s still easier than taking a massive explosion chamber half way around the world.
If you care to look up source literature to get a sense of what was being tried in hyperbaric chambers, you can look up this paper:
Bernhard WF, Frittelli G, Tank ES and Carr JG. Surgery Under Hyperbaric Oxygenation in Infants with Congenital Cardiac Disease. Circulation. Supplement 1964;91-4.
The review of fires in hyperbaric chambers is a bit more modern and was published by the Undersea and Hyperbaric Medical Society, Inc. in 1997:
Sheffield PJ, Desautels DA. Hyperbaric and hypobaric chamber fires: a 73-year analysis.
Care to see what a modern hyperbaric chamber looks like? Try this coverage of the new facility at Prince of Wales Hospital in Sydney – http://www.youtube.com/watch?v=KJMhYzqhLHc (this replaced the one from the photo above).
Oh, and if you wanted to see a bit more about one of our patient’s today, go and look here to meet Felix. http://www.ohi.org.au/east-africa/2014/11/16/felix/