I wandered into the TV room and sat as my family watched the old, 1978 version of Battlestar Galactica. The scene on the bridge was tense, as some poofy-haired guy wandered up to the admiral and reported, “Sir! An incredible number of Cylons are approaching!”, at which line we all burst into laughter. “Incredible number?” Of what possible help could that report be? “Perhaps we should formulate an unbreachable defense!” Tactically, it would be better to have an actual count, right?
And so it is for EMS. We don’t say, “Doc, the patient BP is high!” – it’s 180/110, or whatever. Pulse isn’t “Racing!”, it’s 120. We use actual numbers because they suggest what our treatment should be, and by comparing them afterward allow us to know if our treatment is working.
Now, we’ve been saddled with some useless numbers – GCS for instance, of which I’ve written previously. But there’s always been a number I’ve wanted, something I think an ED, ICU, or floor could really use – and despite looking everywhere I couldn’t find it, until I got a Christmas present.
In school one of the instructors told us that one of the first things a doc will do, on entering a patient room, is glance at the Foley bag (if there is one). For those unfamiliar, a Foley is a bag used to drain urine. A catheter is inserted into the patient’s urethra and threaded into the bladder. A small balloon on the catheter tip is inflated with saline, making it too big to slide back out again. The distal end of the tube connects to a clear bag, which is hung on the side of the bed. The bag has a provision for emptying it without removing the catheter from the patient’s bladder, and the whole setup can be left in place for days at a time. This is usually not a field procedure in our area, but other parts of the country, where transports are long, might do so.
The three things a doc is usually looking at are: Volume (amount of urine), Color, and Flocculence (stuff floating it).
So, Volume. When the catheter is first inserted, there should be some urine output. Over time, of course, the bag fills – the bags are of different capacities, but in general one or two liters. If the patient has had a Foley for a while, and the bag isn’t filling, that’s a Bad Thing – kidneys might not be working. If that’s what you see, ask the RN when the bag was last emptied. If it’s not been emptied by the nursing staff, and it’s only a few milliliters full, you may be seeing kidney failure.
Flocculence is usually Bad. It’s appearance varies – I’ve seen what look like soggy cornflakes floating in the urine – but it can be sediment-like or a simple cloudiness. Flocculence implies bacteria, usually – UTI, bacterial infection of the kidneys, that sort of thing, but can be other material I’m sure.
And Color. This is where I wanted a number. Generally, urine should be clear or pale if the patient is adequately hydrated. Urine is of less volume, but a darker color, if the patient is underhydrated – the urine is more concentrated because the body is trying to conserve what little water it has. Conversely, if you see a patient whose Foley is filled to the brim with clear liquid, chances are they’re way overhydrated, although this can be on purpose if they’re flushing his kidneys.
Rhabdomyolysis is the breakdown of muscle tissue, from trauma or burns, sometimes stroke. It releases a red-pigmented chemical which can overwhelm the kidneys and turns the urine copper- or red-colored, or dark.
We can go on, but basically the point is that the color of the urine can be indicative of underlying processes, and this would be good information to have. And rather than running to Commander Adama on the bridge of the Galactica and shouting like a goof, “Sir, the patient’s urine is really messed up!”, it would be nice to quantify it somehow.
Enter Christmas, for which I received a startup Home Brewing kit. What fun! And in learning all I could about this fun and rewarding hobby, I came across something called the SRM.
The SRM is the Standard Research Method, a scale of color. In Europe they use something called the European Brewing Convention or EBC – same colors, different numbers.
There are hundreds if not thousands of types of beer, and interestingly they range from Clear, through straw colors (pale yellow), to amber, all the way to very, very Black. Just like urine. And there’s a number for each of these. The SRM ranges from 0 through 40; here’s an example, shamelessly pick-pocketed from the Web:
I believe that with some minor tweaking, or perhaps simply expanding the scale, this might serve the purpose of quantifying urine color. Is this a desirable thing? I think so. Charting over time that the patient’s urine changed from SRM 12/S (with sediment) to SRM 6/C (clear of sediment) is showing progress, that kidney function is moving in the right direction. The other way, not so much, the patient’s condition is deteriorating.
Anyway, there it is.