In the past: Possible decompression sickness?

[boulderjohn]

With the information you gave, it is hard to be too helpful without knowing more about the multilevel details of the dives. From a strict PADI table point of view, though, you really were in violation of the no deco limits, and by more than a little.

If I were you, I would rethink my overall approach to diving. You apparently did not give DCS a second thought that day. Start thinking about all those things you were taught in class. You were taught them for a reason, and you ignore them at your peril.

 

[danvolker]

Thanks for the replies! Good to hear that I'm wrong. I put it through on the PADI eRDP before posting and it exceeded limits.

...But that was assuming I was at the maximum depth the entire time which definitely isn't the case.

What is a PFO?

Dave

From medscape.com Patent Foramen Ovale

[ "The foramen ovale is open during fetal life to allow for right to left shunting. For most people this opening is closed at birth by a flap that seals against the atrial septum. However, the flap is not sealed in approximately one third of the population and can open with changes in intrathoracic pressure.^[28] For years, there has been considerable controversy over the relationship between PFO and DCS. Ultrasound examination of divers has demonstrated that venous gas bubbles, which are common after diving and usually filtered by the pulmonary vasculature, can pass through a PFO and embolize the arterial circulation.^[29] Shunting through a PFO may not be apparent at rest because left atrial pressure is usually greater than right atrial pressure almost entirely throughout the cardiac cycle. The exception to this may be during times of certain respiratory movements, such as the period after a Valsalva maneuver when a surge of venous blood transiently increases right atrial pressure. Actions such as straining to lift heavy objects (ie, scuba tanks after a dive) produce a similar effect on venous return.
Regardless of the improbability of paradoxical gas embolism, there have been several reports of possible associations between PFO and DCS. Causality is still unproven, but there seems to be an increased relative risk of developing DCS with a PFO versus without. The exact prevalence of PFO in divers with DCS is not known because of a combination of factors. Interpreting available data is complicated by imprecise diagnosis of DCS and poorly standardized methods of detecting PFO.^[30] The most widely quoted odds radio (OR) for serious DCS with PFO versus without PFO is 2.52 (95%CI, 1.5-4.25) as determined by a meta-analysis published in 1998.^[31] This was with a reported per-dive incidence of DCS of 3.41 in 10,000 dives. In 2003, an extensive bibliographic review of 145 peer-reviewed journal articles related to PFO found no clear agreement regarding the role of PFO in DCS.^[32] From a combined analysis of the contrast transesophageal echocardiogram studies, an OR of 2.6 has been calculated for the development of DCS in divers with a PFO versus those without.^[30] Other authors have concluded that PFO increases the risk for DCS as much as 4.5 times.^[33] A more recent investigation into the functional and anatomic characteristics of PFO has yielded a possible higher risk subgroup. The unadjusted OR to develop DCS for divers with PFO was 5.5 (95% CI 1.8-16.5). However, if stratifying by PFO characteristics, there was no statistically significant difference in risk for DCS for divers with PFO detected only during Valsalva than divers without PFO. There was a significant risk of divers with PFO at rest, with an OR of 24.8 (95% CI 2.9-210.5).^[34]

​

With this knowledge, we should consider our recommendations for diving and PFO based on the absolute increased risk. DCS in recreational divers is extremely rare, occurring after only 0.005% to 0.08% of dives. Presented differently, actual data from DAN's Project Dive Exploration recorded 4 cases of DCS in approximately 14,000 dives.^[13] Evidence supports that the average recreational sport diver need not be screened for PFO. For those already diagnosed as having a PFO, this is not a contraindication for diving. Until we know more, a safe strategy would be to reduce the venous bubble load because it is the bubbles—not the PFO—that are the cause of DCS. This can be accomplished by avoiding dives that require decompression stops, by limiting bottom time, or by the appropriate use of oxygen-enriched breathing mixes.^[35] " ]



My understanding is that about 25% of the US population will have some form of PFO. Some forms are worse for diving than others.
Since the training agencies don't want to lose one quarter of their instruction and gear sales, PFO's are not discussed when people sign up for scuba.
However, one possible reason the tables have changed so much from the 70's ( when I would have just done 60 feet for 60 minutes, and a 60 foot per minute ascent rate)....is that for a population containing this many PFO's, it may be smarter or more coservative to have them use much shorter bottom times at a given depth, and to mandate a slower ascent, and even a "saferty stop".
Aerobic Fitness is greatly neglected in diving, and this is yet another reason for today's PADI tables.

Please do not infer from this that I am suggesting that you should ignore the PADI guidelines. I think you should take them very seriously. I mention this because it should assist with a more comprehensive understanding.

 

[Dave.E]

With the information you gave, it is hard to be too helpful without knowing more about the multilevel details of the dives. From a strict PADI table point of view, though, you really were in violation of the no deco limits, and by more than a little.

If I were you, I would rethink my overall approach to diving. You apparently did not give DCS a second thought that day. Start thinking about all those things you were taught in class. You were taught them for a reason, and you ignore them at your peril.

Buy a $30 capillary depth gauge, submersible watch, and some PADI dive tables so you can avoid this near suicide attempt ever again.

With that being said, judging by your symptoms, it was not DCS, though you most likely put yourself in the region of "silent bubbles".

Did you do a 3-5 minute safety stop after each dive? If so, that may have been your only saving grace.

The lesson was definitely learned with the equipment. I had a bad experience renting gear (depth gauge did not function) and along with me not wanting to inconvenience my buddy I put myself in danger. We did make a three minute safety stop.

I have since purchased a dive computer that runs RGBM (apparently very conservative?) and a backup analogue gauge. I had waterproof tables, slate and dive watch on these dives. We also had them fully planned out with a wheel. I don't think I was being completely reckless but in the end really had no idea if my buddy was following the planned profile because I had no way of knowing how deep we were.

Again, thank you for the replies. I have gotten some useful information and will be taking things more seriously on my next trip.

 

[freewillie]

No way for DCS unless you have a PFO....

Why PFO???

Your previous post of a PFO is correct, but just because you can find evidence of a PFO in 25-30% of the population doesn't mean that it has to be present for DCS/DCI. It will increase the risk but it's true association is still in question. The statistical number just quoted is a post mortem number as well, in that a probe was used to see if they could open the foramen ovale. It doesn't necessarily translate to a physiologic PFO that is open under diving conditions.

It is more likely to be associated with neuologic symptoms associated with DCS. The text book I have for DAN recommendations is that if you "know" you have a PFO you should be aware of the risk and if the person wishes to continue diving they should limit the depth, limit repetitive dives, and avoid decompression dives.

It is relatively easy to diagnose. A cardiologist can do a bubble echocardiogram where bubbles are introduced and then followed by a echocardiogram to see if they pass through to foramen ovale. Personally, I can't remember the last time a patient had a positive test even when they presented with stroke or other neurologic sx suggesting the possibility of a PFO (nondiving patients).

If present they now have catheter balloons that an interventional radiologist can close the hole without cracking the chest open for cardiothoracic surgery.

From the brief description you provided it is entirely possible and more likely that you simply overexerted yourself. You could easily have had a sore biceps from the rock climbing. Even if the dive doctor played it safe and prescribed a session in the compression chamber and your symptoms improved it still does not confirm the diagnosis of DCS. Hyperbaric oxygen helps sore muscles heal as well.

General recommendations apply to avoid DCS. Keep yourself well hydrated, get adequate rest prior to your dives and avoid alcohol in exess before your dive.

As for diving with malfunctioning depth guage, others have already weighed in and you should consider aborting the dive. Discretion often is the better part of valor.

 

[KD8NPB]

The lesson was definitely learned with the equipment. I had a bad experience renting gear (depth gauge did not function) and along with me not wanting to inconvenience my buddy I put myself in danger. We did make a three minute safety stop.

I have since purchased a dive computer that runs RGBM (apparently very conservative?) and a backup analogue gauge. I had waterproof tables, slate and dive watch on these dives. We also had them fully planned out with a wheel. I don't think I was being completely reckless but in the end really had no idea if my buddy was following the planned profile because I had no way of knowing how deep we were.

Again, thank you for the replies. I have gotten some useful information and will be taking things more seriously on my next trip.

That's what we like to hear.

That three minute safety stop may have made all the difference.

 

[freewillie]

Funny, I just happened to pick up the summer 2012 DAN Diver's Alert magazine. A diver had just undergone atrial ablation therapy and the hole in the atrial septum the doctor caused when puncturing the heart to advance the catheter had not quite healed. The cardiologist recommendation was not to dive until the hole had sealed itself. DAN response was you could dive conservatively. Stay shallow, avoid deep dives, keep bottom time very conservative and use Nitrox if possible.

 

[danvolker]

Why PFO???

Your previous post of a PFO is correct, but just because you can find evidence of a PFO in 25-30% of the population doesn't mean that it has to be present for DCS/DCI. It will increase the risk but it's true association is still in question. The statistical number just quoted is a post mortem number as well, in that a probe was used to see if they could open the foramen ovale. It doesn't necessarily translate to a physiologic PFO that is open under diving conditions.

It is more likely to be associated with neuologic symptoms associated with DCS. The text book I have for DAN recommendations is that if you "know" you have a PFO you should be aware of the risk and if the person wishes to continue diving they should limit the depth, limit repetitive dives, and avoid decompression dives.

It is relatively easy to diagnose. A cardiologist can do a bubble echocardiogram where bubbles are introduced and then followed by a echocardiogram to see if they pass through to foramen ovale. Personally, I can't remember the last time a patient had a positive test even when they presented with stroke or other neurologic sx suggesting the possibility of a PFO (nondiving patients).

If present they now have catheter balloons that an interventional radiologist can close the hole without cracking the chest open for cardiothoracic surgery.

From the brief description you provided it is entirely possible and more likely that you simply overexerted yourself. You could easily have had a sore biceps from the rock climbing. Even if the dive doctor played it safe and prescribed a session in the compression chamber and your symptoms improved it still does not confirm the diagnosis of DCS. Hyperbaric oxygen helps sore muscles heal as well.

General recommendations apply to avoid DCS. Keep yourself well hydrated, get adequate rest prior to your dives and avoid alcohol in exess before your dive.

As for diving with malfunctioning depth guage, others have already weighed in and you should consider aborting the dive. Discretion often is the better part of valor.

I think the aspect of this issue I like least, is the concept of an "undeserved hit". To me, in cases where DCS occurs but the diver was well inside the tables.....I would rather position the DCS as having been caused by a PFO, then the ridiculous suggestion of an "undeserved hit".
Something is going to be responsible for the hit in these cases....it is going to be medical like a PFO, or poor fitness, or poor "something"....in which case, it IS deserved, in this manner of speaking

They deal with this huge population of divers, with horrible medical complications all the way to elite athlete, all rolled in to this one population---and then derive safe depth and durations for this group that simply does not have enough in common to be a group.

Then look at special tables like Dr Bill Hamilton and Bill Mee did for George Irvine---and look at run times over twice as long at given depths, with less incidence of a hit occurring. Or, even the Navy tables from back in the 60's and 70's, where we would do 60 for 60.

The issue here, is a table "ought to be" aimed at a specific body type, fitness, hydration and with suggested activity levels all around the dive, and with a lack of medical complications. This reduces the number of variables that get ignored in the present PADI tables.

What we have is a big dog and pony show, where the industry tries to make "the tables" look like a perfected science, while in reality, it is a lot of Voodoo for many individuals ( divers counting on all the fudge factors and rounding and conservatism to protect them. So you end up with a 45 year old accountant that has been sedentary and behind a desk for his entire life, riddled with the physical and medical complications of a life without fitness or good nutrition, now wearing one Thousand dollar computer to base depth times on, plus another as back up. This guy can study the PADI tables and discuss them and then use words like being "conservative"....the thing is, call a spade a spade. It is not being conservative, it is just fudging....It is taking an activity that is absolutely safe for "some individuals", and then by cutting the time in half for the ones that perhaps should not even dive, it is pretending that this duration has "scientifically" determined that it will be safe for them. My point is that it is NOT scientific...what it is, is "marketing" to the masses.

So as not to make this a whine and cheeze post.....What I would call for would be new studies on specific populations with medical and physical and all other obvious "differences" removed from each group---so that the results would allow you to follow the tables for the group your fitness, medical health, diet, hydration, and activity levels around the dive, have you closest to.

We would then end up with perhaps 10 different tables, and then each diver would try to pick the table they would be best able to be "fit" into. The fancy computers could still be used, they would just need to have all ten tables contained in them( be able to compute all 10), for the diver to pick the right one .

Training agencies could then suggest programs that would allow a diver to move from one category of diver tables to another, programs for fitness, reduction of inflammation by diet to address medical problems, etc. Right now, it is mostly ignored. Divers are general population. America has a general population of very unhealthy people, that spend a fortune on health care, due to the NORM that each will have so many medical problems in their life, they could not afford not to have this health coverage. A HEALTHY population would not desire this. A healthy person would not be taking blood pressure drugs, or anti cholesterol drugs, or heart meds, or the other handfuls of pills NORMAL to the average American.

So for now, rather than spending the huge money on fancy computers computing fudge factors over individualization.....the "average" diver would be better off just diving square profiles, staying inside the Padi table, and maybe even breathing Nitrox on the dives --even though using the air tables.....remember, it's all about fudging, and you can do this yourself without wasting thousands of dollars!

 

[RMVSAC]

I think the aspect of this issue I like least, is the concept of an "undeserved hit". To me, in cases where DCS occurs but the diver was well inside the tables.....I would rather position the DCS as having been caused by a PFO, then the ridiculous suggestion of an "undeserved hit".
Something is going to be responsible for the hit in these cases....it is going to be medical like a PFO, or poor fitness, or poor "something"....in which case, it IS deserved, in this manner of speaking ...

Makes perfect sense to me.
Most unexplained phenomenon often lend themselves beautifully to a scientific process.

Thank you Dan, that was a very thoughtful recital.

Note to self: Don't forget to hit the gym before planning a dive trip to Lake Worth FL ;-)

 

[freewillie]

I think the aspect of this issue I like least, is the concept of an "undeserved hit". To me, in cases where DCS occurs but the diver was well inside the tables.....I would rather position the DCS as having been caused by a PFO, then the ridiculous suggestion of an "undeserved hit".
Something is going to be responsible for the hit in these cases....it is going to be medical like a PFO, or poor fitness, or poor "something"....in which case, it IS deserved, in this manner of speaking

They deal with this huge population of divers, with horrible medical complications all the way to elite athlete, all rolled in to this one population---and then derive safe depth and durations for this group that simply does not have enough in common to be a group.

Then look at special tables like Dr Bill Hamilton and Bill Mee did for George Irvine---and look at run times over twice as long at given depths, with less incidence of a hit occurring. Or, even the Navy tables from back in the 60's and 70's, where we would do 60 for 60.

The issue here, is a table "ought to be" aimed at a specific body type, fitness, hydration and with suggested activity levels all around the dive, and with a lack of medical complications. This reduces the number of variables that get ignored in the present PADI tables.

What we have is a big dog and pony show, where the industry tries to make "the tables" look like a perfected science, while in reality, it is a lot of Voodoo for many individuals ( divers counting on all the fudge factors and rounding and conservatism to protect them. So you end up with a 45 year old accountant that has been sedentary and behind a desk for his entire life, riddled with the physical and medical complications of a life without fitness or good nutrition, now wearing one Thousand dollar computer to base depth times on, plus another as back up. This guy can study the PADI tables and discuss them and then use words like being "conservative"....the thing is, call a spade a spade. It is not being conservative, it is just fudging....It is taking an activity that is absolutely safe for "some individuals", and then by cutting the time in half for the ones that perhaps should not even dive, it is pretending that this duration has "scientifically" determined that it will be safe for them. My point is that it is NOT scientific...what it is, is "marketing" to the masses.

So as not to make this a whine and cheeze post.....What I would call for would be new studies on specific populations with medical and physical and all other obvious "differences" removed from each group---so that the results would allow you to follow the tables for the group your fitness, medical health, diet, hydration, and activity levels around the dive, have you closest to.

We would then end up with perhaps 10 different tables, and then each diver would try to pick the table they would be best able to be "fit" into. The fancy computers could still be used, they would just need to have all ten tables contained in them( be able to compute all 10), for the diver to pick the right one .

Training agencies could then suggest programs that would allow a diver to move from one category of diver tables to another, programs for fitness, reduction of inflammation by diet to address medical problems, etc. Right now, it is mostly ignored. Divers are general population. America has a general population of very unhealthy people, that spend a fortune on health care, due to the NORM that each will have so many medical problems in their life, they could not afford not to have this health coverage. A HEALTHY population would not desire this. A healthy person would not be taking blood pressure drugs, or anti cholesterol drugs, or heart meds, or the other handfuls of pills NORMAL to the average American.

So for now, rather than spending the huge money on fancy computers computing fudge factors over individualization.....the "average" diver would be better off just diving square profiles, staying inside the Padi table, and maybe even breathing Nitrox on the dives --even though using the air tables.....remember, it's all about fudging, and you can do this yourself without wasting thousands of dollars!

Ah, now the truth comes out. There is an alternate viewpoint that is being expressed but may not be based entirely on fact. As with most of our Scubaboard post, the OP asks a question. The first few responders answer the question, and then at some point in the thread a few SB'ers get into a discussion about what a poster posted. I think this is where this response is headed.

If Dave happens to read this post, I hope we have answered his question. In part of my response I will try and give my $0.02 as to whether or not he had a DCI hit or simply overexerted himself. The real answer is that we will never truly know if it was DCI or overexertion, but all's well that ends well. For the future it is to avoid the situation in the first place.

The following is not meant to be medical advise, nor to answer specific medical question. It is for education purposes only. I am a board certified internal medicine doctor and have been practicing for the last 15 years in private practice. The following is not just a googled opinion from medical websites, it is based on a few years of actual medical knowledge and medical practice.

First, when making a diagnosis you have to have a certain amount of facts to make a diagnosis. An actual medical diagnosis has what are referred to as the minimum diagnostic criteria. In otherwords, you need the appropriate symptoms, the appropriate corresponding physical findings, and the confirmatory lab test or diagnostic studies. If you need 5 out of 8 criteria for example to make the diagnosis, you don't really get to make the diagnosis until you have all 5 abnormalities or findings. If you only have 4 out of 8, you may be very highly suspcious but you have not quite made the exact diagnosis.

Now, that being said, you still have to treat the patient. If it walks like a duck, quacks like a duck, and looks like a duck, then you are going to be fairly certain that it is some sort of water fowl and most likely a duck although based on the official criteria it is technically not yet a duck. If you treat it like a duck and it was a swan, well, either way it will still get better.

Take for example chest pain. Several criteria are going to go into making the diagnosis of chest pain. Some of the tests are non-invasive like and EKG or echocardiogram. Some of the test are invasive and carry with them an inherent risk of side effects and complications like and angiogram. You would only do an angio for someone who you were pretty damn sure was a duck. Also, your pretest probability goes into making a judgement. A 21 year old college student who runs regularly is not a good suspect for heart attack. On the otherhand, a middle aged or elderly individual who is out of shape, overweight, smokes, and eats bacon for breakfast is generally a regarded as a heart attack until proven otherwise.

For the OP, he had several risks for possibly having DCI. It is unknown since his gear malfunctioned how close he pushed the NDL tables. But his sx of fatigue could be attributed to DCI and having strenous exercise/activity with possible underlying dehydration all fits with possible DCI.

It is also entirely possible that his symptoms were simply exertion overload. He simply wasn't used to that level of exertion over that particular length of time and he has sore muscles because of overuse syndrome.

If the OP presented to an ER he would have been started on intravenous (IV) fluids. If after a length of time his symptoms dramatically got better he would have been told he was dehydrated and advised drink more water before and during his next physical activity. If he still had residual soreness even if it was from overexertion he likely would have been treated anyways in a hyperbaric chamber. It is non invasive and has very little downside except for cost and time. But, even if his symptoms improved it does not confirm that he had DCI since hyperbaric oxygen therapy is often used for wound healing and tissue healing in general. Mild muscle aches for overexertion would also benefit from Navy table 6 recommendations which is the most commonly used therapy for DCI.

But, to say that the OP had a PFO to contribute to possibility of DCI simply because there "has to be reason" for something to happen is not appropriate medical perspective.

Now, divers might have their own opinions to whether or not the tables are accurate or appropriate, but that is a separate argument entirely. But to go about spending time and money on more extensive table is a cost effective measure is a separate debate. In the end no matter how detailed or extensive the tables it still requires user involvment. It is impossible to take into account any number of variables and try and design any system so that no one individual ever avoids a bad outcome. Even if we had more extensive research, knowledge, and for argument's sake the specific tables individualized to body shape, age, activity level there would always be the probability some would still get DCI. It may be less likely granted, but still probable.

I am often asked why something happens. Lots and lots and lots of patient's want to know "why" something happened. Questions often arise, "if this was done differently would 'x' have been avoided." Unfortunately there are often no hard and fast answers. More often than not there is no answer to "why" It simply is what it is. We often joke that medicine in general is an art, not a science. "is this what you call the 'practice' of medicine Doc, and are you 'practicing' on me?!!" Well, kind of.

Patients don't like that. They always say or believe that there has to be a "reason" or something to blame. That might be, and it may just be that current modern medicine does not fully understand what happens. But, for the present, it is what it is.

To the specific question posed by the OP. Possible. Doesn't have to be but given circumstances it could have been DCI, but then again, just because the symptoms fit it doesn't have to be either. The symptoms also fit dehydration and simple overuse muscles as well. Hard to tell. But, in the future if you can avoid the situation by diving conservatively within the current tables and recommendations, and possibly using Nitrox, we may not have to answer the question in another thread, "hey guys, do you think this was DCI?"