What Researchers Did
Researchers studied four divers compressed to 350 meters using heliox to observe changes in their hearing threshold, brainstem evoked response, and acoustic impedance.
What They Found
The four divers experienced no tinnitus, hearing impairment, or earache during compression. While in the hyperbaric chamber, their lower frequency hearing threshold was elevated and brainstem responses showed changes, but these effects were transient and returned to normal after leaving the chamber. No permanent changes were found in their eardrums, acoustic compliance, or stapedius reflex, indicating no damage to their acoustic system.
What This Means for Canadian Patients
This study suggests that specific compression and decompression protocols used in deep saturation diving to 350 meters may not cause lasting damage to divers' acoustic systems. While not directly applicable to general patient care, these findings could inform safety guidelines for Canadian professionals involved in extreme hyperbaric environments or deep-sea operations.
Canadian Relevance
Although not a Canadian study or by Canadian authors, it covers aspects related to decompression, which is a Health Canada-recognized indication for hyperbaric oxygen therapy.
Study Limitations
A significant limitation of this study is the very small sample size of only four divers.