#8208
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From Diver123:
But this also poses the question, what is to squeeze? I dive with my suit tight to my body, but still comfortable to move.
SqueezeBy Fred Bove, M.D., Ph.D.
Perhaps the most troublesome part of diving is the continuous need to avoid the consequences of pressure changes associated with depth. The physical effects of pressure are described by Boyle’s Law, which defines the relation between pressure and volume. Boyle’s Law states that the product of absolute pressure and volume of a gas is constant: P¥V = Constant. If air pressure in body spaces cannot equilibrate with ambient pressure on descent, the forces produced will reduce the volume by squeezing surrounding tissues into the space. On ascent, air in the lungs must be allowed to vent or overinflation will occur. Tissue injury caused by Boyle’s Law effects is called barotrauma or squeeze. The accompanying table shows the changes a five liter volume undergoes as it is subjected to a dive of 100 feet. The greatest volume change is in the first 10 feet. Because the greatest volume change is at the shallowest depth, the most common time for squeeze to occur is during the initial portion of the descent or, in the case of lung barotrauma, during the final portion of the ascent.
SUIT SQUEEZE
Drysuit users may notice painful red streaks on their skin after diving. These are caused by suit folds lying against the skin during descent. Folds containing air are compressed against the skin, the skin is forced into the folds and local injury occurs. Always leave enough residual air in a drysuit so it is not tight against the skin. Wearing a light garment (thermal underwear) under the suit will prevent the suit from sealing tightly against the skin.
All divers will experience the effects of squeeze. Careful attention to equilibration of air spaces during descent and ascent, good dental hygiene, avoiding air swallowing, maintaining equipment and attending to the health of your nose, throat and sinuses are measures that will help avoid injury owing to squeeze or barotrauma.
Sharm el Sheik Emergency and Trauma Center: A new Emergency and Trauma Center in the well-known Red Sea diving resort area of Sharm el Sheik has recently been opened. The hospital, the first of its kind in southern Sinai, specializes in diving medicine and includes a physical therapy clinic and a pulmonary therapy clinic. Sharm el Sheik Emergency and Trauma Center is close to many hotels and the downtown area.
Further information may be obtained by contacting Dr. A.G. Hamada, 8841 Garden Grove Boulevard, Garden Grove, CA 92844 or call (714) 537-6780, fax (714) 537-6782.
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