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In response to what I said:

> >What about all the successful air-only IWR cases, usually performed in
> ><20m max?  Would all of these have been better-off breathing O2 on the
> >surface?  Is it possible that, if dealt with within a few minutes of
> >symptoms, the hydrostatic pressure DOES matter? (Not a pointed
> >question...honest...)

Prime Rat said:

> What about them?  How many successfull IWR on air only compared to HBO (IW 
> or IC) are there?

Of the reports of successful IWR I'm aware of, the air-only attempts outnumber
the oxygen attempts by about 100 to 1.

> Well to find out we would need to take 15-20 healthy 
> age/weight etc matched divers, bend them and treat some with HBO and some 
> with pressure only and test for DCI.  But wait!  It's been done (more or 
> less).  Submarine escape trainees who suffer DCI can be treated effectively 
> and often completely by a single 6 BAR recompression provided it is 
> initiated immediately. Indeed placing the recompression chamber at the top 
> of a submarine escape training tank (instead of having it at ground level) 
> to shorten the time between DCI first being recognised and treatment being 
> started has itself reduced the mortality and morbidity of DCI in this group 
> of people [Van Genderen & Waite 1968].  Once this time "window" is past 
> however, multiple treatments with hyperbaric O2 are required to treat DCI.  

That's the main point of IWR...it can be immediate.

> Thus, although reducing bubble size is important, 2.8 BAR of O2 is affecting 
> some other specific processes initiated by DCI.  Whatever this process is, 
> it has been shown to be further alleviated by other therapies adjunctive to, 
> or in place of, hyperbaric O2.  Many investigations into such treatments 
> have been undertaken [Catron et al 1984; Dutka 1985; Evans et al 1984; Evans 
> et al 1989; 
> Kochanek et al 1987b; Lindsberg et al 1991; McDermott et al 1990; Menasche 
> et al 
> 1985; Spiess et al 1988a] and some hyperbaric practitioners are already 
> advocating use of agents such as lignocaine as an adjunct to hyperbaric O2 
> [Drewry & Gorman 1992; Dutka et al 1992a; Dutka 1990] even though the exact 
> mode of action is unknown.  

Thanks for the references.  It's input like this that gives me IWR
protocol ideas such as:

"If initiated within 10 minutes of symptom onset, include a deep air spike;
if delayed, use oxygen only"

I'm slowly putting together a new, more thoroughly detailed IWR protocol,
with more of a flow-chart basis.  This sort of input is EXTREMELY helpful!

 > Aloha to you also and safe IWR (air or Oxygen)

Thanks, although I hope to never need to try IWR again.....

Mele Kalikimaka (Merry Christmas),

Rich

deepreef@bi*.bi*.ha*.or*

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