Purpose: The frequent ascents made during yo-yo diving may contribute to gas bubble clearance but paradoxically may also increase the risk of central nervous system decompression illness (DCI). We evaluated the risk of DCI due to yo-yo dives with very short surface intervals, using a controlled animal model. Methods: Dives were conducted on air to a depth of 90 meters (10 atmospheres absolute) for 32 minutes of bottom time, at a descent/ascent rate of 10 meters/minute. Sprague-Dawley rats weighing ∼ 300 grams were divided randomly into three groups. Group A performed a square dive protocol without any surface intervals, Group B conducted a protocol that included two surface intervals during the dive, and Group C performed a protocol with three surface intervals. Ascent/descent rate for surface intervals, each lasting one minute, was also 10 meters/minute. Results: Manifestations of DCI were observed in 13 of 16 animals in Group A (81.3%), six of 12 in Group B (58.3%), and two of 12 in Group C (16.7%). Mortality rates were similar in all groups. Conclusions: Surface intervals during dives breathing air significantly reduced DCI risk in the rat. Further studies are required using a larger animal model to reinforce the results of the present investigation.
|Number of pages||6|
|Journal||Undersea and Hyperbaric Medicine|
|State||Published - 1 Jul 2016|
Bibliographical notePublisher Copyright:
© Copyright 2016 Undersea & Hyperbaric Medical Society, Inc.
- Decompression illness
- Gas bubbles
- Yo-yo dive
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Physiology (medical)