What Researchers Did
Researchers measured blood vessel function in the brachial artery of five people before and after a simulated shallow dive (15 metres, 100 minutes) using compressed air.
What They Found
After hyperbaric air exposure, the artery's flow-mediated dilation, a measure of how well blood vessels relax and expand, decreased significantly. Resistance in the artery increased while peak blood flow velocity dropped. These changes suggest even low-pressure dives without decompression sickness can impair vessel function.
What This Means for Canadian Patients
For Canadian recreational and occupational divers working in cold northern waters, this finding suggests that dive-related vascular changes occur even without symptoms of decompression sickness, which has potential long-term implications for cardiovascular health in frequent divers.
Canadian Relevance
This study has relevance to Canadian occupational and recreational divers. Decompression sickness and arterial gas embolism are OHIP-covered HBOT indications, but this study addresses subclinical vascular effects that precede those conditions.
Study Limitations
With only 5 participants, this is a very small pilot study and findings should be interpreted as preliminary.