Preventing Bends?
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Heads Up
Contributor
I was always taught that avoiding certain things COULD help prevent getting bent - for example avoiding drinking alchohol the night before, drinking plenty of water before and after the dive (to keep hydrated) and avoiding strenuous exercise after diving. All these apply ESPECIALLY if you have been pushing your NDL's.
Although I'm not medically trained, from what I've learned through talking to docs and other divers, no-one fully understands why some people get bent and others don't or why a diver can make a certain dive hundreds of times and suffer no injury, only to get a hit the next time.
Same applies to dive tables - they are only empirical (i.e. based on observation) and cannot guarantee that you won't get bent if you dive within them.
Hope this helps somewhat until DR Deco or one of the other medical gurus can give a fuller answer.
Although I'm not medically trained, from what I've learned through talking to docs and other divers, no-one fully understands why some people get bent and others don't or why a diver can make a certain dive hundreds of times and suffer no injury, only to get a hit the next time.
Same applies to dive tables - they are only empirical (i.e. based on observation) and cannot guarantee that you won't get bent if you dive within them.
Hope this helps somewhat until DR Deco or one of the other medical gurus can give a fuller answer.
There are two ways to almost guarantee you won't get bent.
1. Don't dive.
or if you do dive
2. Don't come up.
In other words, if you dive you are taking a chance you'll get bent. There are lots of things you can to to reduse your risk and I believe they've all been covered in these threads, but there is always some risk.
DSSW,
WWW
1. Don't dive.
or if you do dive
2. Don't come up.
In other words, if you dive you are taking a chance you'll get bent. There are lots of things you can to to reduse your risk and I believe they've all been covered in these threads, but there is always some risk.
DSSW,
WWW
Drink plenty of water before, during and after your dive. "Dehydration makes you more prone to decompression sickness." from Adventures in Scuba Diving p52.
Water is the best thing to rehydrate you, caffeine is a diuretic and any drinks containing it will dehydrate you. If you decide to drink Gatorade, you should dilute it with water according to friends who train for triathlons. I believe it's a 50-50 ratio of water to Gatorade.
You can never go wrong with water though. Is there an easy way to tell if you're properly hydrated? Yes, your urine will be clear.
You'll find many other tips on this board and all are good. The reason the obvious tips are obvious is because they are the ones that seem to work the best.
Safe diving!
Ber
Water is the best thing to rehydrate you, caffeine is a diuretic and any drinks containing it will dehydrate you. If you decide to drink Gatorade, you should dilute it with water according to friends who train for triathlons. I believe it's a 50-50 ratio of water to Gatorade.
You can never go wrong with water though. Is there an easy way to tell if you're properly hydrated? Yes, your urine will be clear.
You'll find many other tips on this board and all are good. The reason the obvious tips are obvious is because they are the ones that seem to work the best.
Safe diving!
Ber
Lost Yooper
Guest
Ways to avoid getting bent:
1. Drink lots of water prior to diving.
2. Keep warm during the dive.
3. Maintain good circulation during the dive.
4. Don't dive deep on air.
5. Ascend at 30FPM max.
6. Incorporate deep stops into your profile.
7. Make the last 20' of ascent less than 30FPM.
8. Do not exert immediately following a dive.
9. Switch to 50/50 nitrox at 70' for 5mins if available.
10. Switch to 100% O2 at 20' if available.
11. Don't have any preconditions that might make getting bent a better probability (PFO, obesity, poor physical fitness, etc).
You follow most of that, and you'll never have to worry about getting bent.
Mike
1. Drink lots of water prior to diving.
2. Keep warm during the dive.
3. Maintain good circulation during the dive.
4. Don't dive deep on air.
5. Ascend at 30FPM max.
6. Incorporate deep stops into your profile.
7. Make the last 20' of ascent less than 30FPM.
8. Do not exert immediately following a dive.
9. Switch to 50/50 nitrox at 70' for 5mins if available.
10. Switch to 100% O2 at 20' if available.
11. Don't have any preconditions that might make getting bent a better probability (PFO, obesity, poor physical fitness, etc).
You follow most of that, and you'll never have to worry about getting bent.
Mike
Dr Deco
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Dear tubaloo:
As mentioned on several occasions in these FORUMS, there are two major contributors to decompression sickness. The first is supersaturation of inert gas in the tissues of the body and the other is the concentration of tissue micronuclei.
Because John Scot Haldane developed his tables, and decompression method with the avoidance of gas bubbles in mind, the presence of tissue nuclei has been virtually neglected. In recent decades, the nuclei have been somewhat acknowledged, but the ability to change the concentration has not been thought possible. Thus, table design has concentrated only on gas loading.
From our NASA studies, we have noted the effect of muscle activity on gas bubble formation during decompression. It is very profound. Divers must recall that off gassing is occurring while you are on the boat. Decompression is not over when you reach the surface.
While many speak about various factors in DCS risk, nothing plays a role as much as gas loading and tissue nuclei concentration. Gas loads are governed by time and pressure exposure. They are also controlled by activity levels upon surfacing (e.g., do not go to sleep during the surface interval). To control tissue nuclei, strenuous activity with upper and lower extremities is to be avoided. Do not lift scuba tanks any more than is necessary, climb ladders, run, and other such strenuous activities.
Naturally a PFO can play a very negative role if bubbles are formed during the decompression. This is especially true if Valsalva-like maneuvers are performed. In addition, we have obesity in divers with considerable adipose tissue (= fat) in the abdomen.
Dr Deco
As mentioned on several occasions in these FORUMS, there are two major contributors to decompression sickness. The first is supersaturation of inert gas in the tissues of the body and the other is the concentration of tissue micronuclei.
Because John Scot Haldane developed his tables, and decompression method with the avoidance of gas bubbles in mind, the presence of tissue nuclei has been virtually neglected. In recent decades, the nuclei have been somewhat acknowledged, but the ability to change the concentration has not been thought possible. Thus, table design has concentrated only on gas loading.
From our NASA studies, we have noted the effect of muscle activity on gas bubble formation during decompression. It is very profound. Divers must recall that off gassing is occurring while you are on the boat. Decompression is not over when you reach the surface.
While many speak about various factors in DCS risk, nothing plays a role as much as gas loading and tissue nuclei concentration. Gas loads are governed by time and pressure exposure. They are also controlled by activity levels upon surfacing (e.g., do not go to sleep during the surface interval). To control tissue nuclei, strenuous activity with upper and lower extremities is to be avoided. Do not lift scuba tanks any more than is necessary, climb ladders, run, and other such strenuous activities.
Naturally a PFO can play a very negative role if bubbles are formed during the decompression. This is especially true if Valsalva-like maneuvers are performed. In addition, we have obesity in divers with considerable adipose tissue (= fat) in the abdomen.
Dr Deco
ScubaJorgen
Contributor
I like to make the theory of Dr Deco (about the nucei stuff) a bit more visible and to remember his statements better.
Take two cans of beer out of the fridge. A can of beer is a simple model for a diver. :boozer:
Shake one of the cans heavily. This introduces nuclei in the beer. This can now corresponds to the diver who just exercised in the fitness room.
Open up both cans. This corresponds to decompressing the divers. You probabely see the difference (on the ceiling). That's what's happening in divers who exercise and dive.
PS: if you did not understand it, empty the divers
, get a couple of new ones from the fridge and repeat the experiment. Only not when you are about to dive yourself 
Take two cans of beer out of the fridge. A can of beer is a simple model for a diver. :boozer:
Shake one of the cans heavily. This introduces nuclei in the beer. This can now corresponds to the diver who just exercised in the fitness room.
Open up both cans. This corresponds to decompressing the divers. You probabely see the difference (on the ceiling). That's what's happening in divers who exercise and dive.
PS: if you did not understand it, empty the divers
, get a couple of new ones from the fridge and repeat the experiment. Only not when you are about to dive yourself 
3. Don't fly.
Rick
Dr Deco
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Dear ScubaJorgen:
The shaken carbonated beverage is an example of nuclei generation. In this case, many of the nuclei originate from the air-liquid interface within the can. In your body, the nuclei are thought to form from fluid motion only (we are not in contact with air inside of our tissues).
However they form, it is clear that they are present and play a very big role in whether the beverage will effervesce or not.
While performing a study such as this, it is of interest to note that not all carbonated beverages respond to shaking in the same manner. Some will produce, mush foam (e.g., beer) and some will require only a few seconds following the shaking before it is safe to pop the top. This is a function of the ingredients, and it represents (to some degree) the difference in susceptibility to DCS exhibited by human divers. Some do not bubble much (soda water) and some are Guinness beer.
Dr Deco :doctor:
The shaken carbonated beverage is an example of nuclei generation. In this case, many of the nuclei originate from the air-liquid interface within the can. In your body, the nuclei are thought to form from fluid motion only (we are not in contact with air inside of our tissues).
However they form, it is clear that they are present and play a very big role in whether the beverage will effervesce or not.
While performing a study such as this, it is of interest to note that not all carbonated beverages respond to shaking in the same manner. Some will produce, mush foam (e.g., beer) and some will require only a few seconds following the shaking before it is safe to pop the top. This is a function of the ingredients, and it represents (to some degree) the difference in susceptibility to DCS exhibited by human divers. Some do not bubble much (soda water) and some are Guinness beer.
Dr Deco :doctor:
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