Does effort increase the risk of DCS ?

[boulderjohn]

So did the symptoms go away on their own? How is he doing now?

The swollen face is not a sign I would expect from decompression sickness, but it can be associated with a lung overexpansion injury.

 

[Sandie7]

So did the symptoms go away on their own? How is he doing now?

The swollen face is not a sign I would expect from decompression sickness, but it can be associated with a lung overexpansion injury.

Well, this happened a long time ago ... it seems that when the others saw what was happening, 2 of them descended again with him to the same depth, and stood there for about an hour, slowly ascending. I can't comment due to complete ignorance, but it sounds crazy. However, they were at the bottom of a cliff (they had to climb it to reach the car), and personal cell phones did not exist yet.

He was feeling much better when the 3 of them reached surface.





---------- Post added August 31st, 2014 at 01:28 PM ----------

The time lapse is relevant. It sounds like the friend did not just exercise. He exercised hard immediately after coming up from the dive. Now if he had done a nice long leisurely reef dive and then, as I so often see, the friend did a quick ascent, and then worked really hard that could set it off.

Same for hot tubs. I have heard of folks very quickly after a dive getting in a hot tub and soaking and getting DCS. But lots of folks do it after a break on the surface and do not seem to have a problem.[/QUOTE]

I recently dove with a man who had just participated in a DAN research study. They told him divers should really just laze around deck for the first half-hour after a dive, drinking water, having a snack, and generally not working very hard. They don't even recommend changing out your tanks right away. That's not an official recommendation; just what they told him.

I will certainly keep these in mind !!!!

 

[Nasser]

The number one cause of DCS (apart from blowing a deco stop or ascending too quickly) is dehydration. Drink plenty of water before and after the dive and stay hydrated all day. Avoid overexertion after the dive.

 

[Sandie7]

The number one cause of DCS (apart from blowing a deco stop or ascending too quickly) is dehydration. Drink plenty of water before and after the dive and stay hydrated all day. Avoid overexertion after the dive.

How does water decrease the risk ?

 

[Wookie]

Well hydrated divers move nitrogen out of the blood more efficiently, reducing the chance that a bubble could hang up in a joint or other restriction. Dehydration is probably the leading contributor to DCS, after diving, that is.

We do a fair amount of Doppler studies on my charter boat. These are done on rebreather divers following deep dives, as deep as 100 meters or more. What we have found is that post dive, the diver will lay on their left side and we will ultrasound the heart. You can see the bubbles move through the heart on the ultrasound machine. As little exercise as 3 leg lifts will cause the bubble flow to increase by 10 or more times. Watching it with my own eyes has made a true believer out of me that exercise post dive is a very bad idea.

 

[drbill]

As others have pointed out, a dive to 25 m can indeed result in DCS if appropriate steps are not taken. Back in the days when I did 4-7 dives a day and had to lug all my gear over a mile and back up the hill to my home, I was concerned about potential hits due to the physical activity. I avoided hot showers and made sure I drank plenty of water. Fortunately no problem. Now I just put my gear on my golf cart and drive home... not much physical exertion except for pressing my foot on the accelerator and brake and turning the steering wheel.

 

[dreamdive]

Pre-hydration is less important than post-hydration! That is due to the effect of immersion causing central shunting. I read all the time that you need to hydrate before the dive. That may be true if you were drinking heavily (ETOH) and not hydrating sufficiently AFTER the dive from the day before. The body does not see the "dehydrated" part as you immerse. It becomes an issue however, as you get out of the water as blood that was shunted centrally is redirected to the periphery and a "relative drop in blood volume" may ensue.

Timing matters. The issue of hydration is a lecture of itself.

Excerpt from page 19: Add Helium Resource Library | Add Helium

DCS - Hydration
Blatteau JE, et al – Hemodynamic changes induced by submaximal exercise before a dive and itsconsequences on bubble formation
Br. J. Sport Med 2007, 41:375-9
Germonpre P [/COLOR]– Predive sauna and venous gas bubble upon decompression from 400 kPa
Aviat Space Environ Med 2008; 79: 1100-5
Blatteau JER– Preventive effect of pre-dive hydration onbubble formation in divers
Br. J. Sport Med 2009; 43:224-228
Castagna O, Endurance exercise immediately before sea divingdecreases bubble formation
Eur J Appl Physiol 2011; 111: 1047-54
ConkinJ, et al – Effect of hydration on nitrogen washout in human subjects.Houston, TX: NASA, Johnson Space Center; 1983: 1-20
Gempp E, Preventive Effect of Pre-Dive Hydration onbubble Formation in divers.
British Journal of Sports Medicine 2009; 43: 224-228