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Hi Jason, The article is on the way. As to your recent techdiver post: [Australian IWR protocol] > A number of posters have commented on using IWR for neurological > symptoms; here recommended against. Are different procedures used for > neurological symptoms? What if the patient begins to develop symptoms > during treatment? These are very difficult questions to answer. The biggest problem, I think, with getting IWR accepted is that it is EXTREMELY difficult to standardize. Different situations call for different measures, and nobody really knows which situations call for what methods. The Australian protocol was the first step at a standardization. Another method (the "Hawaiian Method") has been published, and is somewhat different, but not necessarily better or worse. Although the Australian method recommends against IWR in cases of neurological symptoms, this is where I see the greatest merit for IWR. The idea is to stop/reverse symptoms before irreversible damage occurs. As for the second question, I'd bet in most cases, if symptoms got worse during IWR, they'd probably get worse faster on the surface. Of all the reported cases of IWR that I am aware of, symptoms never got worse DURING the IWR treatment. The cases of detrimental IWR involved symptoms that appeared to get worse after termination of the IWR treatment. > What can the attendant actually do for the patient, in the > experience of IWR users? Can he switch the patient from high O2 to low > O2 (air) in the event of convulsions? Can he deal with any medical > problems which develop - unconsciousness, panic, acute pain, vomiting, > eaten by sharks? In my own experience with IWR, the primary benefit of the tender is to relay information back & forth between the diver and the surface support. Although the following is contrary to all published IWR methods, and although I KNOW I'm inviting a burst of flamethrowing: in my PERSONAL opinion, I see the tender as optional, particularly in cases where the "victim" is an experienced decompression (technical) diver. HOWEVER, the worst case of detrimental IWR involved two divers off Sussex who re-entered the water in an apparent attempt to treat DCI symptoms, and dissapeard (their bodies were recovered two weeks later). In this case, a tender might have prevented the tragedy. [More IWR protocol] > What is the recommended maximum sea state for this sort of thing > - I would have thought it is much more sensitive to minor pressure > changes than non clinical decompression. That's a call the diver and support have to make. As an interesting tangent, Phil Nuytten once told me that, in their experience with in-water DEcompression on their commercial diving operations, the incidence of DCI went DOWN when the sea was rough (go figure...). He thinks the rhythmic compressions from passing swells somehow increased inert gas elimination or decreased bebble growth/formation. I'd like to see some controlled studies on that one, but Phil's anecdotal experience rates almost equally with controlled scientific study in my book. > How does the attendant assess the patients improvement; or is it > entirely subjective? How much improvement is improvement? What about > switching from O2 to air (25:5 mins) to avoid chronic O2 toxicity? Assessing the patient's condition is pretty much something the patient has to decide. Chamber operators have some tools for somewhat more objective assessment (I've had the "wheel of death" run up the inside of my thigh more times than I care to remember), but they also rely heavily on the patient's own assessment. As for taking air breaks, that's one of the things David & I recommended in our review article. > > 5. If oxygen supply is exhausted, return to the surface, rather > > than breathe air. DO NOT LET THE PATIENT BREATHE AIR UNDERWATER. > > > Is there a reason for this? If O2 is so much better at depth, > why is air worse? Ok, there will be elevated nitrogen present - does > this outweigh the advantage of keeping the DCI lesion under compression? > Is this the view of studied experience, or educated guesswork? All of this is basically educated guesswork (but so is a LOT of chamber treatment protocol...like I said in an earlier posting, we're not talking exact science here.). The Australian method discourages air IWR because of the risks associated with additional gas loading (and possibly worsening the symptoms). The Hawaiian Method incorporates an "Air Spike" to deeper water prior to a long O2 hang at 30 feet. The record of reported cases suggests that air-only IWR can and has performed miracles (the vast majority of reported cases are air-only). Who knows what the best answer is? Would I do IWR with air only? Probably; almost certainly. Would I recommend it to one of my deep diving companions? Sure. Would I recommend it to all technical divers? Probably not (we discouraged it in our review article). Would I recommend it to recreational divers? No way. Yes it works, yes it has strong theoretical disadvantages. The solution, as always, is to learn as much as you can about it, and be responsible for your own decisions (that's directed at everyone, not just you). > > 6. After surfacing, the patient should be given one hour on oxygen, > > one hour off, for a further 12 hours. > > 25:5 mins? Why hour to hour? I'm not sure why this pattern was chosen; however, I'd suggest that it is no more arbitrary than 25:5. With such a wide scope of individual variation, there really is no way to come up with exact "best" figures. > hmm, I hope I didn't sound too picky, but I hope there's a lot > more information than that available to anyone planning on setting up > for IWR. The review article I just mailed you covers everything we could find on the topic. > (Or, nightmare of nightmares, is that the extent of knowledge > in chambers, too.... :-( ). You might be surprised....;-) Aloha, Rich deepreef@bi*.bi*.ha*.or*
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