What Researchers Did
Researchers exposed 34 healthy people to shallow air saturation for 48 hours at two different pressures, then rapidly brought them back to normal atmospheric pressure in about two minutes.
What They Found
None of the 19 subjects exposed to the shallower pressure (1.77 ATA) developed decompression sickness (DCS), but 4 out of 15 subjects (26.7%) exposed to the deeper pressure (1.89 ATA) were diagnosed and treated for DCS. Almost all subjects in both groups had detectable gas bubbles in their veins for up to 12 hours after decompression, and those treated for DCS saw these bubbles return hours after hyperbaric oxygen treatment. The duration of these gas bubbles, along with a subject's body weight and age, were linked to symptoms and bubble presence.
What This Means for Canadian Patients
This study highlights that even relatively shallow and short hyperbaric air exposures can lead to decompression sickness, a condition recognised by Health Canada for hyperbaric oxygen therapy. Canadian divers, pilots, and others exposed to pressure changes should be aware that rapid decompression, even from seemingly mild exposures, carries a risk of DCS and venous gas emboli. The findings reinforce the importance of proper decompression protocols to prevent DCS, which can be treated with hyperbaric oxygen therapy.
Canadian Relevance
Although this was not a Canadian study, it covers decompression sickness, which is a Health Canada-recognised indication for hyperbaric oxygen therapy.
Study Limitations
This study involved a small number of subjects and was conducted in 1986, meaning the methods and understanding of decompression sickness may have evolved since then.