safety

Summary of "ALERT DIVER" article, July/Aug 2009, p. 68-70

Study of 947 diving deaths of U.S. and Canadian residents during 1992-2003 by:
Richard Vann, PhD, Vice President of DAN Research,
And Petar Denoble, MD, D.Sc., DAN Senior Research Director.

Triggers:
The most common triggers accounting for 86% fatalities with identified triggers:
     •insufficient gas (41%) – need of emergency backup gas.
     •entrapment (20%) – need focused training on prevention.
     •equipment problems (15%) – no particular equipment component seemed to dominate.
     •rough water (10%) – high seas, currents, surf, rocks or piers.
Disabling agents:
     •emergency ascent (55%) – need coping training for emergencies - may be the key.
     •insufficient gas (27%) - needing greater stress on gas management skills – staying with your buddy.
     •buoyancy trouble (13) – negative buoyancy found far more frequent than positive.
Rapid ascent was witnessed or recorded by dive computer in more that half the cases with emergency ascent, but emergency ascent also included divers who were assisted to the surface, made free ascents, panicked or buddy-breathed. Insufficient gas was often preceded by entrapment and occasionally by failure of the breathing apparatus. Negative buoyancy was more common than positive buoyancy in these events and when present throughout the dive may lead to increased exertion.

Disabling injuries:
The most common:
     •asphyxia (33%)
           o entrapment (kelp, wrecks, etc), insufficient gas, equipment trouble and rough water -excessive gas consumption from heavy exercise.
     •AGE (arterial gas embolism) (29%)
           o Above triggers and strongly associated with emergency ascent.
           o ~3/4 deaths when they exhausted breathing gas, panicked, or equipment problems.
           o with loss of consciousness during ascent, at the surface or just after leaving the water.
     •Cardiac incidents (26%)
           o ~ 60% noted breathing difficulty, fatigue, distress, chest pain or ill-feeling.
           o Loss of consciousness occurred before, during or after diving.
           o Autopsy indicated significant cardiovascular disease but rarely of heart muscle damage and age over 40 years – might not have had a fatality on land.
           o AHA (American Heart Association)- Fitness evaluation needed for cardiac risk divers before beginning or resuming diving.

Make your dives safer:
Take the time to refresh your skills when necessary, plan your dive with your buddy, watch your gas supply, and try to avoid panic. Sit out a dive if you’re not feeling well, and call DAN with any questions you have about your diving health. DAN is here for you so you can keep on enjoying the sport of diving.

Be sure to review the full report in the "Alert Diver", Sonia Smith