What Researchers Did
Researchers tested three experimental decompression ascent profiles, including those with added "deep stops," on divers in a hyperbaric chamber to see their effect on bubble formation compared to the standard French Navy 90 (MN90) tables.
What They Found
In Protocol I, all divers developed Spencer grade 2-3 bubbles, and one diver experienced decompression sickness after using the experimental deep stop profile, with no statistical difference in bubbling compared to the standard profile. Protocol II's experimental profile produced severe bubbling in all eight divers, leading to the discontinuation of experimental profiles with longer deep stops. Protocol III, using a single, shorter deep stop, again showed no difference in bubbling between the standard and modified profiles.
What This Means for Canadian Patients
This research suggests that adding "deep stops" to standard decompression tables for deep dives (50-60 msw) does not consistently reduce bubble formation and can even increase the risk of severe bubbling or decompression sickness. For Canadian divers, this highlights the critical importance of adhering to validated decompression protocols to prevent decompression sickness, a condition often treated with hyperbaric oxygen therapy.
Canadian Relevance
Although not a Canadian study, it covers decompression sickness, which is a Health Canada-recognized indication for hyperbaric oxygen therapy.
Study Limitations
The study involved a small number of participants (eight per protocol) and some experimental protocols were stopped early due to safety concerns.