Freediving and DCS

Do breath-hold divers get decompression sickness (DCS)? While DCS in scuba diving is a well-recognized disease, much less is known about breath-hold divers who suffer DCS when diving too frequently or too long with regard to depth. Few case reports exist in current literature, but with improvements in technology (better fins, warmer wetsuits) and training methods as well as increased use of battery-propelled devices, today’s divers dive longer and deeper than ever before. Thus, DCS cases among breath-hold divers could potentially be seen more frequently in the future.  

Starts: September 2020

Prevalence of Venous Gas Emboli After Freediving.

The primary goal of this study is to collect high-resolution data on breath-hold divers’ depth/time profiles to further our understanding of decompression illness. This will include field experiments monitoring the divers diving as they normally would and then incorporate testing for nitrogen gas bubbles in the blood (using noninvasive ultrasound). To correlate these findings with physiological responses we will also measure heart rate and lung volumes and use an additional laboratory experiment for more extensive, detailed testing. There are a few studies on genetic traits that may be involved in the physiology and pathophysiology of diving, but these studies are few and preliminary, so we aim to collect and analyze the subjects’ genes regarding both known and suspected variants. We believe that data from these studies will increase both diving safety and understanding of basic human physiology.  

This study is a collaborative effort between the University of California, San Diego (UCSD), the University of Guam (UOG), and DAN. The field studies will be conducted in California, Hawaii, Guam and Florida with measurements taken either on shore or on a boat.