This is going to be a bit of a departure from the normal fare that gets posted around here, so be forewarned. I'm learning more about disease and health care - which is kind of why I'm here - and some of the things I'm learning are a bit counter-intuitive. Expressing things in textual form helps me think through things, which is largely why this space operates.
So if you aren't interested in the technical side of health care, feel free to skip. Otherwise read on.
I really am at school now, even if it doesn't look like it very often.
All of the below is based primarily on stuff I know. I make no claims to its accuracy, but it all sounds right to me. If you're asking me for medical advice, you're asking the wrong guy.
When a patient presents to the emergency room, the triage nurse, ED nurses, house staff, and attendings are all running through a list of things they're looking for. In fact, the list can be summerized in a single item: organ failure. If all your organs are functioning properly, then no matter what condition you've got, it ain't gonna kill you, no matter how much it hurts. On the other hand, if your organs stop working - especially your heart - you die. Pretty much right then and there if it's your heart or brain, but in a matter of minutes to hours for other organ systems.
There are a few key things to watch for in terms of organ failure. This list is fairly short, and consists of things that will kill or permenantly impair you in very little time: MI, stroke, kidney failure, respiratory problems, and adequate dehydration and circulation/profusion (while not organ failure as such, inadequate hydration or profusion leads to organ failure really quickly). I'd add trauma to the list, but that tends to be something you don't have to look particularly hard to discover.
The reason that health care providers look for those things is because when it comes down to it, those are the only things that will actually kill you. Cancer doesn't kill people. Never has. When a cancer grows to the point that it interferes with the operation of your organs, you die, but only because your organs have stopped working. The cancer itself is only as dangerous as its potential to harm other parts of you. So when someone "dies of cancer", what is really being said is that the cancer grew to the point that it impaired the working of the deceased's organs to the point that they could no longer support life.
AIDS hasn't killed anyone either. You can live for years with AIDS. What kills you is opportunistic infections that attack immuno-compromised individuals. Most people don't have to worry about internal fungal infections because the human immune system is really good at killing them, but if you don't have an immune system to speak of... bad things happen. One of the reasons that AIDS patients in developed countries do so much better than those in developing countries is that the odds of normal, everyday infection by normal, everyday diseases is so much lower.
With this in mind, there are basically two kinds of diseases: those that will certainly kill you unless something else does first, and those that will only kill you if you can't kill it fast enough. The first category consists of things like ALS and MS, which are, in essence, a form of chronic, gradual organ failure. These will kill you every time, but in many cases, this takes so long that people die of something else - including old age - before these diseases do the job.
The other kind of diseases are things that don't actually kill you outright, but can compromise the functionality of your body to the point that you die. These can be divided into infections - bacterial and viral - and other things, like cancer and various genetic diseases. Take the black death, for example. This is a bacteria, Yersinia pestis, that still kills a few people out West every year. It has bubonic, pneumonic, and septisemic courses and is still quite serious: septisemic plague is universally fatal without medical treatment. Why? Because the infection is so powerful that your organs shut down before the body has time to marshal an adequate defense. But if you can get the patient to the hospital, administer antibiotics, and stabilize their vitals, they'll live. In 85% of cases reported, patients were able to be stabilized in the hospital.
This is basically the way it works: you get sick. The infection, viral or bacterial, starts to multiply, and frequently releases toxins into the bloodstream. But the body works to fight the disease, and in all but a few cases - HIV being a notable one - the body will eventually defeat the invader. Dysentary is caused by a bacteria that the body can defeat every time, but as the bug causes vomiting and diarrhea, you can dehydrate so fast that you'll die before the immune system has a chance to work. But with IV fluids and antibiotics, you'll be fine.
Cancer works a little differently, because it's your own body gone nuts. Still, every cancer treatment course currently out there is essentially a way of poisoning you in such a way that the cancer dies faster than you do, whether that's with drugs or radiation. That's why chemo patients are so sick: they're getting pumped full of toxins that the cancer, because it tends to consume materials much faster than the rest of the body to support its growth, will be affected by at a greater rate than you will. This doesn't always work, but it's all we've got at the moment.
Sepsis is a very serious condition that accounts for more deaths in ICU patients than anything but coronary disease. Sepsis is the systemic infection of the body by one of a number of bugs, and leads to inflammation, impaired circulation, and systemic organ failure. It is divided into SIRS (systematic inflammatory response syndrome), severe sepsis, and septic shock (sepsis with organ failure). Mortality rates are 20%, 40%, and >60% respectively.
Sepsis is a "disease" (it's really a response to one of any number of actual diseases, but the response is fairly uniform) in the second category. It won't actually kill you outright, but can cause the organ failure that will. But if you can stabilize the vitals - O2 saturation, blood pressure, etc. - patients do a lot better. The trick is doing that, because you can't tell someone has sepsis just by looking at them. They'll complain of fever and general malaise, if they're responsive at all, but you can't tell if your kidneys have stopped working on your own. It involves pretty technical diagnostic tools: bloodwork to detect the presence of lactic acid in the bloodstream, indicating poor profusion. Culturing blood samples to detect and identify infections. Unfortunately, diagnosing sepsis can take so long that by the time the patient gets to the hospital, they're already really sick. Once systemic organ failure starts, it's really hard to get people back to health. It's doable, but it's always better to prevent organ failure in the first place.
I'm getting involved in a project that is trying to do just this. A company has developed a catheter which can be used to monitor vital signs in real time - O2 saturation, blood pressure, but especially lactic acid counts, which previously took a bit of time to get - and administer things like pressors, antibiotics, and fluids like any other catheter. The idea is to identify patients with sepsis very early, and get them immediately on a 6 hour treatment course, attempting to stabilize their vitals by any means necessary (epinephrine is part of the clinical pathway if necessary).
All I'll be doing is managing the patient database. Mostly chart abstraction, but it's a way to get involved. I'm pretty excited about it, as the physician I'm working with is really great.Posted by ryan at February 24, 2005 12:47 PM