The bends itself is not an accident, it is a statistically predictable event, one that will occur in a certain percentage of dives, regardless of how good a diver is or what precautions are taken.
(Dr. Bill Hamilton)
I decided to write this article after reading Bernie´s Chowdhyry´s book,” The Last Dive” where I found this accurate sentence from Dr. Hamilton about the Decompression Sickness (DCS), also known as “the bends”. The book narrates the true story of Chris and Chrissy Rouse who died because of DCS after a deep dive trying to identify a u-boat found and finally identified by John Chatterton.
It was the beginning of the 90´s, a time when just a few non commercial nor military divers used gas mixes different than air for deep dives, the reason why it was “pretty normal” to suffer diving accidents.
It might happen to you.
Nowadays these mixes are easily available for all the divers and with its regular use the chances of getting the bends has decreased. But still, lots of cases are registered every year.
I had an accident myself in 2019 that brought me to the hyperbaric chamber. After a regular open water dive I suffered DCS type II. A bubble got stuck in my spine cord creating stomach cramps and parestesia (numbness) in my leg, starting in the foot and going up to the hip. Because of the quick response from my colleagues and the boat crew providing oxygen and taking me to the hyperbaric clinic I was fully recovered after only one treatment in the chamber and a few weeks out of the water. Doctors couldn’t find a logic explanation for my DCS. After a while I got to the conclusion that going back in the water shortly after recovering from an ankle fracture combined with dehydration and tiredness was the cause of the bends.
The bends, a taboo.
The Rouse´s accident happened in 1992, but still in our days divers who suffered DCS don´t like to talk about it. It is seen as a stigma in the career of any recreational or professional diver. This is because we have the wrong idea that only doing improper things or breaking the rules or the limits we can get hit by the bends. But it would be right to say that there are deserved and undeserved hits. A diver can follow all the rules and procedures and still get the bends. The hyperbaric medicine could not yet find the reason why sometimes divers suffer DCS and other times they don´t, doing everything by the book or not.
I was surprised when I had the accident and talked about it that more people than I thought, even close friends, had been in the same situation as me. Why hide it? It was an accident. Same as a car one, sometimes is your fault and sometimes is not.
Everything we go through is a lesson and we can learn from others’ experiences. The more we know about DCS the better prepared we will be to prevent it.
How to avoid it
No need to say that to avoid any diving accident we have to stay within our training and skill limits. Respecting ascend rate and safety and deco stops we decrease the risk of DCS. But there are many other factors that have influence in the formation of bubbles in our system. We are talking about some of them in this article.
Practising regular sports improves our general shape. Circulatory, respiratory, muscle and bone systems are directly affected by keeping an active lifestyle. Muscles get more irrigation than fat, which makes that transforming fat in the muscle will increase blood circulation, decreasing the possibility of bubble formation that could lead to DCS.
Having said this, is important to avoid doing high and medium effort activities right after diving. Increasing heart beating and metabolism could cause bubbles to form. For that reason practising sports after diving is not recommended.
There are many physiological conditions that could encourage DCS. Hypertension or high cholesterol level could influence the formation of bubbles in our blood stream. Being healthy is very important not only to avoid diving accidents but also for our life in general.
It doesn’t matter if it is before or during the dive, the increase in the breathing rate will lead to a bigger absorption of nitrogen in our tissues. A fast and shallow breath because of overexertion, such as swimming against a current, could also cause hipercapnia (CO2 excess) in our lungs, which will make us breathe even faster to try to get more O2, causing the diver, at last, to faint.
Keeping a high hydration level is key, not only for diving, but for our day to day life. We are made mostly by water. The percentage of water varies from 50 to 70 depending on our age, health and nutrition. A good hydration will cause our blood to flow properly, being able to perform the gas exchange in an appropriate way.
Getting dehydrated we are losing water and minerals, what could cause cramps, dizziness, headache and tiredness amongst other things.
Travelling to tropical places, such as the Riviera Maya, we need to increase the water consumption because the humidity in the air will make us sweat profusely, which will cause fluid loss, decreasing the percentage of water in our body.
Injured and/or scarred tissues are less irrigated than healthy ones. The decrease of blood vessels in any part of our body could cause DCS because the gas exchange is not conducted in a proper way.
Drinking alcohol before a dive is totally discouraged. And not only for obvious reasons as having impaired mind and performance, but also for getting the body dehydrated.
Flying or climbing mountains
The decrease in the air pressure in both of these environments could lead to the formation of bubbles in our system. Is highly recommended to wait at least 12 hours before doing any of these activities.
There are many factors that can help DCS to show up and as we have said before, Hyperbaric medicine is far from reaching decisive conclusions about the reasons why under the same circumstances some divers develop DCS and some don’t. Until science can determine the causes it is better to do anything in our hands to try to avoid any diving accident. Respecting our limits and diving skills, being healthy and in good shape and following a good diet looks like a good start point.