Paul Haynes
CCRX Supporter
Hi
For those who might have been present, I gave a presentation at Oztek last month titled Increasing The Probability of Surviving Loss of Consciousness Underwater When Using a Rebreather. This presentation was based upon a paper I hope will be published this year in one of the diving and hyperbaric medical journals.
Resistance to Mouthpiece retaining strap use by manufactures, training agencies and instructors is I believe no longer tenable. We now have 20 years of sport rebreather diving behind us and accident data clearly demonstrates that in over 90% of rebreather diving fatalities, the actual cause of death is drowning (DAN study). This was clearly foreseen and documented at Rebreather Forum 2 (RF2) back in 1996 which was organised to address the major issues involved in bringing rebreather technology to the consumer market-place and was divided into working sessions to identify the key technology, safety, training and risk management issues. Despite the RF2 prediction regarding drowning as the most likely cause of death, the sport rebreather industry has still not addressed the matter of airway protection following LoC even though it is a design requirement of the rebreather standard EN14134:2013. The aim of my Oztek presentation was to stimulate the rebreather diving community (manufacturers, trade bodies, training agencies, instructors, divers) to re-visit the use of rebreather mouthpiece retaining strap, which has the potential to delay or limit water aspiration following loss of consciousness, thus extending the life of an unconscious diver for what might be a sufficient period of time for rescue. Rebreather divers do not die of equipment failure, human error, hypoxia, hypercapnia or hyperoxia, these are accident triggers, disabling agents or disabling injuries, in the vast majority of cases (over 90%) rebreather divers die from water aspiration and drown.
"I approached the diver and noticed the mouthpiece was out" is a common theme to rebreather fatality witness reports. I believe we as a diving community have the ability to reduce the frequency of drowned rebreather divers. However to do so will require a culture change. Thirty odd years ago legislation was proposed in the UK where the use of seat belts in cars would become law. The vehicle manufacturers opposed it, the motoring public opposed it. Thankfully this did become law and overnight vehicle accident fatality figures dropped significantly, to the point where within a few weeks there was a shortage of donor organs. Despite the original resistance, a culture change happened and how many of us would now consider driving without wearing a seatbelt. In a similar manner by which we no longer accept that being propelled face first through a glass windshield is an acceptable aspect of driving, we should no longer accept that aspirating water and drowning is the immediate effect of loosing consciousness underwater.
The vast majority of classic and contemporary military rebreathers come with a retaining strap because the potential safety benefits have long since been recognised by the original users of rebreathers - the military. Evidence from military rebreather diving demonstrates the safety benefits of using a mouthpiece retaining strap to prevent or delay water aspiration following loss of consciousness. After 20 years of sport rebreather diving, the use of a retaining strap as a standard safety feature is long overdue.
You'll find a lot of interesting discussion here on a separate posting from a couple of years back that generated over 32,000 views. It is worth while going back to review the issues discussed.
Rgds
Paul
For those who might have been present, I gave a presentation at Oztek last month titled Increasing The Probability of Surviving Loss of Consciousness Underwater When Using a Rebreather. This presentation was based upon a paper I hope will be published this year in one of the diving and hyperbaric medical journals.
Resistance to Mouthpiece retaining strap use by manufactures, training agencies and instructors is I believe no longer tenable. We now have 20 years of sport rebreather diving behind us and accident data clearly demonstrates that in over 90% of rebreather diving fatalities, the actual cause of death is drowning (DAN study). This was clearly foreseen and documented at Rebreather Forum 2 (RF2) back in 1996 which was organised to address the major issues involved in bringing rebreather technology to the consumer market-place and was divided into working sessions to identify the key technology, safety, training and risk management issues. Despite the RF2 prediction regarding drowning as the most likely cause of death, the sport rebreather industry has still not addressed the matter of airway protection following LoC even though it is a design requirement of the rebreather standard EN14134:2013. The aim of my Oztek presentation was to stimulate the rebreather diving community (manufacturers, trade bodies, training agencies, instructors, divers) to re-visit the use of rebreather mouthpiece retaining strap, which has the potential to delay or limit water aspiration following loss of consciousness, thus extending the life of an unconscious diver for what might be a sufficient period of time for rescue. Rebreather divers do not die of equipment failure, human error, hypoxia, hypercapnia or hyperoxia, these are accident triggers, disabling agents or disabling injuries, in the vast majority of cases (over 90%) rebreather divers die from water aspiration and drown.
"I approached the diver and noticed the mouthpiece was out" is a common theme to rebreather fatality witness reports. I believe we as a diving community have the ability to reduce the frequency of drowned rebreather divers. However to do so will require a culture change. Thirty odd years ago legislation was proposed in the UK where the use of seat belts in cars would become law. The vehicle manufacturers opposed it, the motoring public opposed it. Thankfully this did become law and overnight vehicle accident fatality figures dropped significantly, to the point where within a few weeks there was a shortage of donor organs. Despite the original resistance, a culture change happened and how many of us would now consider driving without wearing a seatbelt. In a similar manner by which we no longer accept that being propelled face first through a glass windshield is an acceptable aspect of driving, we should no longer accept that aspirating water and drowning is the immediate effect of loosing consciousness underwater.
The vast majority of classic and contemporary military rebreathers come with a retaining strap because the potential safety benefits have long since been recognised by the original users of rebreathers - the military. Evidence from military rebreather diving demonstrates the safety benefits of using a mouthpiece retaining strap to prevent or delay water aspiration following loss of consciousness. After 20 years of sport rebreather diving, the use of a retaining strap as a standard safety feature is long overdue.
You'll find a lot of interesting discussion here on a separate posting from a couple of years back that generated over 32,000 views. It is worth while going back to review the issues discussed.
Rgds
Paul
