Blood Test for Decomp hit ???

A friend of mine recently was hospitalized in a south Pacific location for a potential decomp hit. Fortunately he was only suffering from bad case of dehydration. During his time, they ran a blood test for decomp sickness.

How can this be ????

Gas chromatograph for N2??

I'm no doctor, but I think a blood test is standard operating procedure in this situation. One reason might be to check for (or rule out) infection and/or other problems that could be cause symptoms presumed to be DCS, and/or which might complicate or compromise hyperbaric treatment. They also could be looking for fibrin-fibrinogen degradation products (FDP). This test can help distinguish between type 1 (neurological damage) and type 2 (musculo-skeletal) DCS, helps in evaluating seroius type 1 DCS, and could be useful in determining the correct course of hyperbaric treatment.

Quite a few years ago I was a test subject for research into high-altitude diving tables.

We spent the summer diving profiles and used some tests to see how close we'd pushed it.

One test was doppler investigations of blood flow and bubble inclusions. The other was a blood draw for clotting factors and a H & H... it was very obvious when RBC's were clumping around microbubbles.

All the best, James

Hi,

Having read the above I do would like to make a few comments without wanting to be a pedantic smart-ass.

From my experience within the medical field (yes, I happen to be medical doctor with a great interest in diving medicine) I have often seen and heard how non-medically trained people interpret medical knowledge/facts and pass that on to others, often with the best intentions. So please, please, please be very careful about giving out medical advice to others when you don't have the proper training.

I'm not claiming to be an expert on diving medicine, but as far as I can recall that particular test Frogfish (Robert) mentions was never mentioned during the courses I took. I did a quick Google and maybe you're referring to this article Aviat Space Environ Med. 1976; 47(9):993-4 First of all, this article dates back to 1976, that's 30 years ago and alot has happened since, and the study has only been done with 18 patients...that's very few.

I would like to refer to "Bennet and Elliott's Physiology and Medicine of Diving", 5th Edition (It's considered to be the "Bible of Diving Medicine"...it's very dry literature though about a wet subject).

I would like to quote

(Chapter 10.6 Manifestations of Decompressions Disorders; Diagnostic Methods p 587): "There are no highly sensitive or specific diagnostic investigations for DCI. Equally there are no investigations that have been shown to correlate with the response to treatment. Thus the history and clinical examination remain the principle techniques for assessing patients. ...."

(Chapter 10.6 Manifestations of Decompressions Disorders; Hematology and Biochemistry p 593): "There are no sensitive and specific hematologic or biochemical markers for DCI. Most attention has focussed on the hematocrit, which has been noted to rise in severe cases of DCS, but which is often normal in cases with significant symptoms. Moreover, it is not clear whether increased hematocrit is a marker of disease or a predisposing dehydrated state. ...."

From what I've seen and heard, most cases of decompression illness are treated with a USN Table 6 and during the course of that table, patients are continuously monitored and assessed at regular intervals. The result of such an evaluation will determine if the Table 6 is extended or switched to another Table (at greater depth)

Again, I don't claim to know all, but I think the blood sample taken from the person mentioned in the first post was simple a standard procedure to have an idea of his/her hematologic and biochemistrical status, e.g. to rule other other illness.

If you have any more questions about or an interest in diving medicine, there is a very good website available Scuba-doc and Dr Ernest Campbell is willing to answer most of your questions.

Hope i'm making any sense without having created even more confusion

Regards,

Bart

More likely the CBC and Chemistry Profile, and maybe urine analysis, confirmed dehydration. These are pretty standard admission tests for most emergency rooms. Treat with fluid, patient gets better, diagnosis confirmed.

According the physician who runs the local hyperbaric chamber, the following test is used to determine whether a patient has DCS when the diagnosis is not clear:

Patient is placed in the chamber and begins first Navy Table 6 treatment.

If the signs and symptoms subside, the patient has DCS. If the signs and symptoms remain, the patient probably doesn't DCS.