Since an episode of SCLS is always characterized by hemoconcentration (namely, a decrease in plasma relative to red blood cells because the plasma is leaking out) let me reiterate something I wrote more than a year ago, when I was still having episodes of SCLS, in a Discussion Forum titled "How to Know When You Are Having an Episode of SCLS," now on page 6 of that section:
"I would like to report that I have recently made good progress in identifying the presence or absence of an episode of SCLS in the following way. First, I now have (and use whenever I feel like it) a sophisticated medical device that measures my hemoconcentration within seconds: I prick one of my fingers and use the 2nd or 3rd drop of blood to fill a so-called microcuvette with some active chemicals in it, which when inserted into the device gives me a fast, objective hemoglobin (Hgb) reading — no matter where I am or whether it is a night, weekend or holiday.
The device is made in Sweden, approved by the FDA for institutional or medical use, and is available to doctors, hospitals and blood banks around the world. (It is used mostly for the opposite purpose, namely, to spot persons with anemia.)
It is not yet FDA-approved for home use in the USA, so one of my doctors bought it for himself and then resold it to me at cost. (I later submitted the bill to my health insurance company for reimbursement and, after denying payment at first, they ended up covering most of the cost once they got a letter from my doctor explaining how use of the device would help minimize the kind of frequent, expensive hospitalizations I had been needing – and they had been having to pay for.)
The device is called HemoCue Hb 201+ (see it at www.hemocue.com) and it can be obtained by a medical professional in many countries around the world. The device has a one-time cost of about US$850 and a recurring cost consisting of a package of 200 microcuvettes (with 4 containers of 50 each, with a shelf life of about one year when unopened and 3 months once a container is opened) that costs about US$200 each, and which you have to buy one or twice a year, depending on frequency of use. [For more details on it, see the Disorder Details section.]
The reading you get is usually a few decimals different than the one a hospital or professional lab gets using venal blood drawn at the same time, but it is accurate enough to give you and your doctors a sufficiently approximate level – and to catch increases in hemoconcentration as they happen (for example, by taking a sample every 3-4 hours when you suspect you may have started a capillary leak episode) at home or on the road. As a result, I no longer need to guess whether I am or am not having an episode, and if by chance I am having an episode, I can get the medical help I need, wherever I am, long before my blood pressure starts to collapse and I go into shock."