Management of Mild or Marginal Decompression Illness in Remote ...

The Effect of Delay to Recompression on Mild Cases
We know very little about the impact of delay in mild cases. Surrogates for delay have
suggested that late treatment is less effective, and intuitively, we believe delay to be
harmful. However, this assumption is not always based on data. There is no information
in the literature about the effect of time on outcome in mild cases, and it is safe to
say that even for serious cases, the data we possess does not have adequate resolution
in the very early time periods.
Surrogates for Studies on the Effect of Delay to Treatment
Although no prospective studies have assessed the effect of delay to treatment on outcome,
surrogates for delay have been used and analyzed. The dive site’s distance from
the treating chamber is an example of such a surrogate. In DAN’s 2003 Diving Report,
the delay time was plotted against percent relief by chamber distance (Figure 2). The
figure suggests that the closer a diver is to a chamber, the better the outcome.
Unfortunately, this interpretation is subject to many valid methodological challenges,
primarily based on non-equivalent diving conditions, diver practices and reporting
motivation.
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Location and Outcome
(DAN 2001)
100
hours
80
60
40
% Relief
Delay
20
Figure 2. Dive location and outcome from 2001 data.
Literature
The scientific literature is not clear on the effect of delay to recompression on patient
outcome. Authors attribute both high and low importance to its influence, and studies
can be found that support both positions. Examples follow.
The Case for Delay as a Predictor of Outcome
It is commonly stated that prompt treatment for DCI is crucial for a good outcome.
This position is intuitive, convenient and difficult to refute. In the abstract to his review
article on the treatment of decompression illness, Moon states "the patient should be
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