Helium and oxygen treatment of severe air-diving-induced neurologic decompression sickness
A. Shupak, Y. Melamed, Y. Ramon, Y. Bentur, A. Abramovich and S. Kol
Israel Naval Medical Institute, Israel Defense Forces Medical Corps, Haifa.
BACKGROUND: The use of helium and oxygen recompression treatment of
neurologic decompression sickness (DCS) has several theoretical advantages
over the traditionally used air and oxygen recompression tables that have
been confirmed by findings from recent animal experiments. OBJECTIVES: To
evaluate the outcome of patients with neurologic DCS who had been treated
with a helium-oxygen protocol and to compare it with that of a
retrospective control group that was treated with air-oxygen tables.
DESIGN: The study and control groups included 16 and 17 diving casualties,
respectively. The severity of neurologic DCS was estimated according to a
9-point scale weighting motor, sensory, and sphincter control functions.
The study group was treated with a helium-oxygen decompression protocol,
and the control group was treated with the US Navy air-oxygen Table 6 or
6A. Persistent residual dysfunction was treated in both groups with daily
hyperbaric oxygen sessions, at 2.5 absolute atmospheres for 90 minutes,
until no further clinical improvement was noted. SETTING: The Israel Naval
Medical Institute (Israel's national hyperbaric referral center), Haifa.
RESULTS: Significant clinical score increments were found for both the
helium-oxygen- and air-oxygen-treated groups: 2.8 +/- 2.4 (mean +/- SD) and
7.4 +/- 1.1 at presentation vs 7.6 +/- 2.1 and 8.1 +/- 1.5 at discharge,
respectively (P < .001 and P = .005, respectively). Although the score
at presentation was significantly lower for the helium-oxygen-treated group
(P < .001), no difference was found between the groups' average outcome
scores. While most of the improvement in the patients in the study group
could be attributed to the helium-oxygen treatment and not to the
supplemental hyperbaric oxygen, in the control group, no significant
difference could be demonstrated between the scores at presentation and at
completion of the air-oxygen recompression table. In 5 patients who were
treated with the use of the air-oxygen tables, deterioration was observed
after recompression. No deterioration or neurologic DCS relapse occurred in
the helium-oxygen-treated group. CONCLUSION: The results suggest an
advantage of helium-oxygen recompression therapy over air-oxygen tables in
the treatment of neurologic DCS.
