Decompression Sickness, Caisson Disease or ‘the bends’
An update regarding DCS popped into my in box a few days ago from DDRC which reminded of a situation experienced by a fellow diver. We teach the effects of DCS and the symptoms however it is not until you read or hear a true story that it brings it home.
You will see from the timeline described below it is not one single factor which caused the problem however a culmination of things. The activities were not confined to the day the person experienced DCS. The DCS event started over a timeline of 36 to 48 hours.
This is not intended as a “finger point” or an exercise in hindsight.
Time spent diving causes an excess of inert gas, such as nitrogen, to dissolve in the body. When a diver surfaces this dissolved gas may form bubbles, which then cause local damage to body tissues or obstruct small blood vessels. This can result in a wide range of symptoms including pain, weakness, dizziness or tingling.
It is our resposibility as good Dive Buddies to be able to recognise DCS and how to deal with it. There are a number of suitable SDC (Skill Development Courses) which not only improve your diving but also provide you with the skills in an emergency.
If you do no other course then Oxygen Administration is the only thing we can provide to a fellow diver when DCS or suspected DCS experienced.
My experience of DCS – Decompression Sickness
Due to the job I do I like to understand the reasons why things are the way they are. Having spent 20 hours in a Hyperbaric Chamber over the last couple of weeks I’ve had plenty of time to think and to go back and piece together the jigsaw puzzle that is the reason why I got bent. My story begins two weeks before “the incident” happened. As an Open Water Scuba Instructor, I know that anxiety and stress are things to look out for in my students, not just specifically about the diving but also generally.
Stress raises your heart rate and increases your circulation. An increase in circulation will result in more nitrogen being absorbed in the body tissues. I was not stressed about the diving. Far from it. It was a welcome distraction to my personal situation. However, I was under emotional duress and therefore experiencing stress.
FACTOR 1: STRESS AND ANXIETY
I did what people do. I got busy! My weekend had started with a run round a very hilly, woody circuit. Normally I run alone a couple of times a week at a comfortable pace and for about 40 minutes. In need of social contact, I joined some friends and ended up running “at pace” for over an hour. It was a push for me, and the hills were a challenge, but I was pleased I had been able to keep up with the others. Running dehydrates you and dehydration makes your blood thicker. This reduces blood flow (“perfusion”) and increases the risk of Decompression Sickness by reducing the body’s ability to release nitrogen.
FACTOR 2: DEHYDRATION (Physical exercise pre-diving)
After a large bacon butty (salty!) and a mug of tea (a diuretic), I got a quick shower, changed and then headed off to the pool. As there wasn’t much going on student wise, myself and two other instructors got together in the pool and practiced skill demos for an hour and a half. Diving itself dehydrates you. If you are in a wet suit, your body is in contact with water and the brain sends signals to reduce the actual content of water in your body. You pee more and lose water through the skin.
FACTOR 3: DEHYDRATION (Immersion Diuresys)
My evening was spent with a friend talking. This was accompanied by a few glasses of red wine. It was a valuable evening spent putting my topsy turvy world to rights. I crawled into bed at 12.30pm, pleased to have achieved much in the day and relieved to have talked.
FACTOR 4: DEHYDRATION (Alcohol Consumption) FACTOR 5: FATIGUE
The arrangements for Sunday’s “fun diving” had been to meet up at Stoney Cove for 10.20am (ish). I was diving with 3 guys I regularly dive with and another guy that I had dived with once a year before. I got a text message from him at 7am. He was already at Stoney! I was awake, so I decided to get up there a bit earlier too.
I sprang into action Lara Croft style.
After some decisive packing, tea and toast to go and (oh dear!) just enough fuel in the tank to get me there, I was on my way up the motorway. By 8.35am I was queuing up for the top car park, and by 9.30pm was jumping in the water for my first dive. Our first dive was to the Stanegarth, a sunken Tug that sits on the 22-metre shelf of the quarry. From there we managed to find the Armoured Personnel Carrier and then it was slowly back up the cliff to the 7-metre shelf for a potter around and safety stop. We were down for 36 minutes. The water temperature was 7 degrees!
FACTOR 6: COLD WATER TEMPERATURE
The absorption of nitrogen into the body tissues may be slower in colder conditions due to a narrowing of the blood vessels (vasoconstriction). It also means that the release of nitrogen from the bloodstream is also slower, particularly in “slower” body tissues such as fat, nerves and bones which do not receive a large supply of blood. The other three guys arrived at about 10.30am to find us enjoying our first surface interval with bacon and egg rolls and tea (salty food, diuretic drink!). After 1 hour and 45 minutes on the surface we went down for a dive with the others to the Hydro Box, which sits on the 32-metre shelf.
FACTOR 7: REVERSE PROFILE DIVES
The second dive was 10 metres deeper than the first dive. This is known as a “reverse profile”. Some textbooks recommend that a second dive should not be more than 12 metres deeper than the first dive. There is no evidence to prove that reverse profiles increase the risk of DCS. However, talking afterwards to the dive physician and to the Hyperbaric team, anecdotal evidence is to the contrary. During the second surface interval I felt tired so, after carrying my tank to the compressor room, I enjoyed a twenty-minute power nap lying on the grass in the Winter sun. I was peckish but didn’t bother getting any food and didn’t drink water as I would normally.
FACTOR 8: LOW BLOOD SUGAR FACTOR 9: DEHYDRATION (Not drinking enough water)
After a 2-hour surface interval, we went in for our third dive. We went back to the Stangarth (22 metres) and I took some photos of the guys on the deck. I am a very slow mover when I dive, but I was moving around more than usual to go in and out of the tug’s hold and to take the photos.
FACTOR 10: PHYSICAL EXERTION UNDER THE WATER
After about 20 minutes I started to feel really cold. I signaled to my buddy that I wanted to go back and we signaled to the others to go on without us. We headed slowly back up the cliff and then, after a safety stop, ascended super slowly up the steps to “the bus stop” to get out. When I got out I felt really cold. I also felt that my breasts had gone really hard and my nipples were sore. I assumed that this was the effect of having been in the cold water. Now I know that this was because my lymphatic system was not draining properly and the lymph nodes under my armpits had swollen up as a result. Swelling is a symptom of DCS.
SYMPTOM 1: SWELLING (Lymphatics not draining)
I ditched my kit, grabbed my bag and swiftly headed for the changing rooms. Having used the toilet and changing I suddenly felt very weak and light headed. I sat down and asked a lady for water. Then I really started to feel bad. I laid down on the bench and asked her to get my friend from the car park. She used my mobile phone, and when he came in I asked for a sweet cup of tea, thinking that was all I needed! What happened after that is a bit of a blur. I drifted off. Whilst I remember hearing voices and was vaguely aware of what was happening, I couldn’t command my body to react and respond properly.
SYMPTOM 2: EXTREME LETHARGY/ALTERED CONSCIOUSNESS
I stayed lying on the bench and was put on O2. Then I started wrenching and vomiting quite violently. SYMPTOM 3: NAUSEA AND VOMITING Someone was asking me to open my eyes. Then they were asking me to touch my nose. I tried to but could hardly move. They were using my name a lot. I remember that much. Then there were new voices in the room. The ambulance crew had arrived. They put a drip in (so I’m told) and moved me to the ambulance using a chair. I remember feeling very cold and very tired. I couldn’t move my limbs and I couldn’t open my eyes. The ambulance took me the short distance to the waiting helicopter and the West Midlands Air Ambulance team took over from there.
I heard more new voices, and then bleeping sounds as they hooked me up to the monitors. Whirring blades, and then a ride that seemed to last an eternity to the Hull and East Riding Hospital. I missed seeing the team in their red boiler suits with the very useful pockets. My friend later told me all about it. Another ambulance took me to the hospital once we’d landed. By the time I was moved to the bed in the assessment room, I was able to string a few sentences together in explanation and could open my eyes to see the people around me. I was beginning to feel more lucid but still didn’t want to move my head as the feelings of dizziness and disorientation were overwhelming.
SYMPTOM 4: DIZZINESS AND DISORIENTATION
Within 3 hours of getting out of the water, I was being wheeled on a trolley into a Hyperbaric Chamber. The first evening I spent 4.75 hours in the company of a hyperbaric nurse and under the watchful eyes of 2 others who were “manning the submarine” from the outside. My head was enclosed in a small oxygen tent connected to a plastic ring with a rubber neck seal and for most of the time while I as in there I breathed 100% Oxygen. I just lay there feeling like a limp rag doll.
Afterwards, when they moved me onto the bed in my room, I threw up again, but felt better afterwards! The following morning I felt better but still couldn’t move my head without feeling really dizzy. My treatment in the chamber was with other patients and so I had to go in a wheelchair. This involved moving which wasn’t a pleasant experience. I was in for 90 minutes this time. All I wanted to do was lie down and keep still. I want my family and friends to know that the phone calls I received on that Monday and personal visit were a real boost when I was feeling very low indeed.
By the Tuesday morning, I’d managed to get myself up, have a bath and get dressed. This was major progress. I had another treatment and then went home in the afternoon. I was still feeling very disorientated and was given drugs to help with this.
ONGOING SYMPTOMS: FATIGUE, DIZZINESS AND DISORIENTATION
Back at home on the Wednesday I was walking around as if I was half drunk. I kept forgetting what I was doing or saying. I stopped taking the drugs as they were making me feel really “spaced out”. On the advice of a friend, I phoned the Doctor the following morning. He had seen me only 2 weeks before for my annual dive medical. By 2pm I was sitting in his office in Harley St, London, and by 3.30pm I was in the London Diving Chamber. The diagnosis was Type 2 DCS.
My cerebral nerve tissues had been starved of oxygen by the nitrogen bubbles that had formed, and the tissues were damaged. This explained my “fuzzy head”. It was like my brain had had some of its “leads” disconnected! The Hyperbaric Oxygen Therapy I received in the Chamber was helping to radically speed up the healing process. On session in the chamber is the equivalent of 3-4 weeks normal healing time. After the first session in the LDC, this time with an oxygen mask over my mouth and O2 supplied “on demand”, I came out feeling euphoric! I went back down to London on the Friday for a further 2 x 90-minute sessions. This time I came out feeling really unwell and slightly unsteady. I was told this was a normal effect of breathing the O2. Apparently my “sharpened Rombergs were a bit off”!
I went back on Monday and yesterday (Tuesday) for another 2 sessions a day. When I woke up on the Tuesday morning I felt as though a cloud had lifted from my head. I felt human again! The nausea from the oxygen lasted a couple of hours after the end of each session, but the healing effects were well worth it.
Today is Wednesday. I’ve written this whilst in the chamber for what I hope is my last session. I’m off to see the Doctor in Harley Street shortly and I hope that he can see how much of a difference the treatment has made. Quick and repeated HBOT treatment has meant that I have recovered so much quicker than I would have done. I have learnt a great deal about DCS. You have a lot of time to read when you are in the chamber. When I’m teaching again I will be much more aware of the risks. Whilst I would never seek to put anyone off diving, particularly novices, I will be reinforcing the education for prevention of DCS as part of my classroom presentations. My thanks go the Hyperbaric teams in London and Hull and to my “dry dive” buddies. It was a pleasure to spend time in confined space with you! However, I hope I never have to see you again!!!! Post Script: The Doctor has given me the all clear. I can return to the pool in 10 days, return to confined water teaching in 6 weeks and, after another full medical, can return to normal diving in 3 months time. I can’t wait.
SISAC organise Skill Developement Courses throughout the dive year to suit all qualifications. We welcome non-members to join us. Why not contact us for a schedule of the next courses. Call 01480 708029 or complete the contact page.