This article on advanced life support is part of the Science in Sci-fi, Fact in Fantasy blog series. Each week, we tackle one of the scientific or technological concepts pervasive in sci-fi (space travel, genetic engineering, artificial intelligence, etc.) with input from an expert.
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About the Expert
Stacey Berg is a pediatric oncologist who loves it when the medical details in speculative fiction are either technically accurate or really outrageous. She is the author of the science fiction novels Dissension and Regeneration. She is represented by Mary C. Moore of Kimberley Cameron & Associates. You can visit her at www.staceyberg.com and find her tweeting about medical research, writing, and whimsy as @slbscifi.
Advanced Life Support for Writers
Many of us grew up with the neat, clean Sickbay on the starship Enterprise as our vision of future hospitals. Much science fiction still presents a picture of medical care so advanced that it approaches magic. In these stories, a fully clothed patient lies on a narrow bed, sometimes with a monitor blinking above the head. If there’s a blanket, it’s usually some shiny metallic cloth. But for those of you who’d like to write some more realistic medical scenes, let’s talk about how Intensive Care Units work in our current version of reality.
When does a patient need ICU care?
Patients are usually in the ICU when they need support for critical organ function. Whether patients are sick from sword cuts, plagues, spaceship crashes, ray gun blasts, or other big injuries, the body is likely to respond in pretty much the same way: failure of one or more of our organs.
The most important organ, of course, is the brain. The brain needs a constant supply of oxygen and glucose (our main fuel) or it will die within minutes. The body will sacrifice as much as it can to preserve the brain, but at some point it will need technological help. Thus, unless your story’s setting permits personality transplants into other bodies, or includes artificial brains, your medics will have to do what we do now, which is support all the other organs to try to keep the brain going.
What organs do we support, and how?
The prime directive, if you will, is to keep oxygen and glucose,the sugar that’s the body’s primary fuel, flowing to the brain. The body naturally does this by using the lungs to extract oxygen from air and transfer it to red blood cells, which the heart then pumps to the brain (and other vital organs).
Notice that this process starts with blood! Catastrophic bleeding is a main cause of out-of-hospital trauma deaths. (You can learn simple skills to “Stop the Bleed” and save someone’s life here). We can restore a patient’s blood volume with blood transfusions (If you’re healthy enough to donate blood at your local blood bank, please consider it! Find a blood bank near you). More interestingly for science fiction writers, medical researchers are working hard to develop artificial blood, using genetically engineered hemoglobin or fluorocarbons that carry oxygen.
Support to Pump You Up
Assuming that blood or a substitute to carry the oxygen is present, the next thing we need is a way to get it pumped around the body. This is obviously the heart’s job. If the heart can’t perform its function as a mechanical pump, we can help it in a number of ways.
First, we can give medicines that improve the heart’s muscle function, making its muscle contract harder. Second, we can provide direct mechanical help. Temporary or permanent devices can be implanted to help the heart pump. Short term devices include balloons that are inflated and deflated in the aorta. Longer term solutions include “left ventricular assist devices,” or “LVADs”. Some of these work with pulsatile pumping like the heart, but others use continuous flow. One tidbit of interest for your story is that a patient with a continuous-flow LVAD might be walking around perfectly fine yet have no pulse!
It is also possible to place a person temporarily on a heart-lung bypass machine, with the excellent science-fictional name “extracorporeal membrane oxygenation,” or ECMO. This is used most commonly if the lungs are also failing. If a patient’s heart needs to be replaced completely and permanently, the choices are a heart transplant from another human, or an artificial heart. Human hearts work better, but the supply is limited (unless you’re writing a Kazuo Ishiguro-type novel). Total artificial hearts work, though our versions are still much less sophisticated than Jean-Luc Picard’s. One problem with them is that you always need to have spare batteries around.
Ventilators: Blow Me Away
Once the blood delivers its load of oxygen to the brain and other tissues, it needs to circulate back through the lungs to pick up more. The lungs’ job is to grab oxygen from air and put it into the blood, while exhaling waste carbon dioxide. Injured lungs are less efficient at transferring oxygen to the blood, so we provide supplemental oxygen. We can give low levels or oxygen through nasal prongs or a face mask, but for more severe lung problems (or if the patient’s chest muscles aren’t working) we can use a ventilator. In this setting a tube is inserted into the patient’s windpipe, then attached to a pump that provides the breaths.
There are variations for very sick patients, called high frequency ventilation, where the breaths are so tiny and fast that we can’t see the chest rise and fall. If the lungs are damaged so badly that they can’t transfer air to the blood at all, we can use ECMO as discussed above to replace lung as well as heart function. We don’t have implantable artificial lungs but patients with chronic lung diseases can get lung transplants.
You might notice that with ECMO we can theoretically have a living patient with no pulse and no visible breathing. Right now that patient would be about as sick as it’s possible to be and still have a chance to recover. But one day…
Liver and Kidney Support
Somewhat less urgent than circulation of blood is the need to manage fluids and waste. The liver is a critical organ that detoxifies waste and drugs (including “xenobiotics,” a fancy word for foreign substances that is excellent to include in science fiction). The liver also makes proteins, especially those that help the blood clot. Patients with acute liver failure get very sick very fast.
Artificial livers are the subject of major research efforts, but right now the only replacement for a failed liver is a transplant. Unlike other organs, livers can regenerate, so a living donor can provide a piece of liver for transplantation into another person. Both the donor’s and the recipient’s livers will grow back to normal size.
The kidneys are responsible for balancing the body’s fluids as well as excreting waste. You can live about a week with zero kidney function, in contrast to nearly immediate death from complete failure of heart, lung, or liver function. Dialysis machines are essentially artificial kidneys that people can attach themselves to for several hours a day to filter blood and fluids. The machines are about the size of a large microwave and tubing carries the patient’s blood through the machine and back. People can live almost indefinitely on dialysis, but quality of life is usually better with a kidney transplant. Just as with liver transplant, living donors can provide a kidney, but in this case, both donor and recipient end up with one kidney each.
What Does Modern Life Support Look Like?
A patient in the ICU with organ failure is sick. There are IV lines and tubes and pumps all over the place, and monitors showing all kinds of waveforms and numbers. (In some ICUs this information is transmitted to a central nurse/doctor station by telemetry, also a useful idea for science fiction). Patients on ventilators are almost always heavily sedated and often getting high doses of pain medicines. Sometimes very strong muscle relaxants are used so the patient can’t “fight” the ventilator. Often goopy artificial tears are used and the eyelids are loosely taped to protect the eyes because the patient can’t blink.
The patient is usually wearing a loose hospital gown—definitely not a ship-shape Star Fleet uniform. Patients often have severe swelling of the face and limbs, so they don’t look like their normal selves. If they are awake, they may be quite confused. For all these reasons, having a loved one in the ICU is a very stressful experience—something important to remember for your supporting cast.
Of course, all this is the contemporary state of our science. As science fiction writers we can extrapolate from here, advance and miniaturize the technology, and grow replacement organs literally on trees if we want to. Start from a realistic foundation, and the advanced life support you imagine for your story future will seem all the more realistic.
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Thanks for this! Great advice for any writer who does not wish to rely entirely on the healing power of Handwavium and large doses of Impossibilium and Unobtanium…
I would endorse the above as a good introduction to management of the critically ill
I am a physician form the UK