Hyperventilating at 110 feet

[Kevrumbo]

Kevrumbo,

You realize that you are quoting a biomedical study that is 35 years old.

Here is the abstract of that study:
Undersea Biomed Res. 1978 Dec;5(4):391-400.
Roles of nitrogen, oxygen, and carbon dioxide in compressed-air narcosis.

Hesser CM, Fagraeus L, Adolfson J.
Abstract

In an attempt to determine the roles of nitrogen, oxygen, and carbon dioxide in compressed-air narcosis, the effects on performance (mental function and manual dexterity) of adding CO2 in various concentrations to the inspired gas under three different conditions were studied in eight healthy male volunteers. The three conditions were: (1) air breathing at 1.3 ATA; (2) oxygen breathing at 1.7 ATA; and (3) air breathing at 8.0 ATA (same inspired O2 pressure as in (2)). By relating performance to the changes induced in end-tidal (alveolar) gas pressures, and comparing the data from the three conditions, we arrived at the following results and conclusions. A rise in O2 pressure to 1.65 ATA, or in N2 pressure to 6.3 ATA at a constant high PO2 level, caused a significant decrement of 10% in mental function but no consistent effect on psychomotor function. A rise in end-tidal PCO2 of 10 mmHg caused an impairment of approximately 10% in both mental and psychomotor functions. The results suggest that, at raised partial pressures, all three gases have narcotic properties, and that the mechanism of CO2 narcosis differs fundamentally from that of N2 and O2 narcosis.
Roles of nitrogen, oxygen, and carbon di... [Undersea Biomed Res. 1978] - PubMed - NCBI


SeaRat

So what? --study is 35yrs old?? It's still qualitatively very relevant to the OP.

"The Meyer-Overton hypothesis states that narcosis happens when the gas penetrates the lipids of the brain's nerve cells. Here it apparently interferes with the transmission of signals from one nerve cell to another. Exposure to nitrogen-oxygen mixture at high pressure induces narcosis, which can be considered as a first step toward general anesthesia. . . and narcotic potencies of inert gases are attributed to their lipid solubility."

The above is the Meyer-Overton hypothesis put forward in 1899–1901, and is still current & basic oft-cited reference/textbook material for Recreational to Technical Scuba Courses & Training (see PADI Encyclopedia of Recreational Diving Ch.5/p22). . .

To Recap:

Taken from Undersea Biomedical Research, Vol 5, No. 4 December 1978 Hesser, Fagraeus, and Adolfson:

"Studies on the narcotic action of various gases have shown that the ratio of narcotic or anesthetic potency of CO2 and N2O approximates 4:1, and that of N2O and N2 30:1. From these figures it can be calculated that CO2 has at least 120 times the narcotic potency of nitrogen. Our data would suggest that the narcotic potency of CO2 is even greater, i.e., several hundred times as great as that of nitrogen."

Dr. Bookspan is the author of Diving Physiology in Plain English and various medical board review courses for hyperbaric medicine.

"Carbon dioxide retention is now viewed as a contributor to oxygen toxicity and nitrogen narcosis, suspected as a contributor to decompression sickness, and implicated in incidents of underwater confusion and loss of consciousness."

Deep Air with increased Gas Density & Work-of-Breathing; then throw in Physical Exertion or a Stress Condition, resulting in overbreathing the regulator --all leading to the Vicious Cycle of CO2 Retention and sudden Narcosis. Can result in severe cognitive impairment at depth or worst case stupor and ultimately unconsciousness. . . the issue here is to break this vicious, panic inducing & building feedback cycle of Narcosis and CO2 retention by immediately aborting the dive. Ascend properly & smartly with your buddy to your safety stop, deploy your SMB as needed, and surface.

Also implicating the insidious nature of CO2:

Lanphier and Camporesi. Chapter 5. Respiration and Exertion, The Physiology and Medicine of Diving:
1. Higher Inspired Oxygen (PiO2) at 4 ata [30m/100'] (404 kPa) accounted for not more than 25% of the elevation in End Tidal CO2 (etCO2) above values found at the same work rate when breathing air just below the surface.
2. Increased Work of Breathing accounted for most of the elevation of PACO2 (alveolar gas equation) in exposures above 1 ata (101 kPa). . .
3. Inadequate ventilatory response to exertion was indicated by the fact that, despite resting values in the normal range, PetCO2 rose markedly with exertion even when the divers breathed air at a depth of only a few feet.
further references to support the quote above:
Lanphier. Nitrogen-Oxygen Mixture Physiology, Phases 1 and 2. NEDU Report 1955-07. RRR ID: 3326

Lanphier, Lambertsen, and Funderburk. Nitrogen-Oxygen Mixture Physiology - Phase 3. End-Tidal Gas Sampling System. Carbon Dioxide Regulation in Divers. Carbon Dioxide Sensitivity Tests. NEDU Report 1956-02. RRR ID: 3327

Lanphier. NITROGEN-OXYGEN MIXTURE PHYSIOLOGY. PHASE 4. CARBON DIOXIDE SENSITIVITY AS A POTENTIAL MEANS OF PERSONNEL SELECTION. PHASE 6: CARBON DIOXIDE REGULATION UNDER DIVING CONDITIONS NEDU Report 1958-07. RRR ID: 3362

Lanphier. Nitrogen-Oxygen Mixture Physiology. Phase 5. Added Respiratory Dead Space (Value in Personnel Selection tests) (Physiological Effects Under Diving Conditions). NEDU Report 1956-05. RRR ID: 3809

 

[openmindOW]

Do not trust a DM to stick to a dive plan, plan a dive, or keep you safe. In fact rely on them only for a site briefing. Then plan your own dive and stick to that.

Jim, you have made this point before on this Board. I appreciate what you are saying.

However, I do want to point out that it would be very understandable if new divers were to feel that they are expected to follow a dive boat's DM. Dive boats are not dcemocratic instituions. There's a captain. Divers are expected to follow the directions of the crew.

I have been on a number of dive boats on which the DM effective says, "Follow me; we are going dowon to _____ ." It is understandable if divers believe that they are required to follow the DM under such circumstances.

Personally, I hate doing that kind of diving. That's one reason that I love to dive the Florida Keys, where dive operators are less likely to do that.


Dive Operators need to get away from the "follow the DM" kind of diving, in my view.

 

[danvolker]

Jim, you have made this point before on this Board. I appreciate what you are saying.

However, I do want to point out that it would be very understandable if new divers were to feel that they are expected to follow a dive boat's DM. Dive boats are not dcemocratic instituions. There's a captain. Divers are expected to follow the directions of the crew.

I have been on a number of dive boats on which the DM effective says, "Follow me; we are going dowon to _____ ." It is understandable if divers believe that they are required to follow the DM under such circumstances.

Personally, I hate doing that kind of diving. That's one reason that I love to dive the Florida Keys, where dive operators are less likely to do that.


Dive Operators need to get away from the "follow the DM" kind of diving, in my view.

In Palm Beach, the Dive Guide ( often a DM) gives the briefing, then anyone that "desires" to follow him or her, gets into the "group" following the Guide....He tows a float/flag so they don't need to worry about towing their own, or whether they will get to the best parts of the reef that the guide discusses he would be going to in the briefing..... If there were 20 divers on the boat, there might be 6 to 10 max that would decide to follow the guide...on some trips with mostly advanced divers, this could be the Dive Guide by himself or with one buddy
Of the divers that begin to follow the guide on a dive, if any of them see something they get interested in, and decide to spend more time looking at it, and the Dive Guide wants to keep going...they just stay....the guide swims away, and that is it. There is no concern by anyone over this, because the guide is only there as a potential tool to help find something you might like to see--the guide knows this, as do the divers.

When you have a really weak or poorly trained diver, and they visit Palm Beach, the boat( Captan and crew) definately want to know about this person and their lack of skills immediately. Often this is discerned by the nervous behavior and lack of skill in gearing up....Ultimately, the first dive they are seen on, will showcase extreme lack of required skills.

Where a diver is indentified as poorly skilled and in need of baby sitting, the crew typically discusses what can be done, based on the diver mix on the boat, and availablity of DM's or willing advanced diver babysitters. In extreme cases, the diver would be taken aside and told that they need some work with an instructor prior to diving on that boat again....The concept of a poor skilled diver needing to HIRE a DM or Instructor in order to dive becomes valid in this case also.

When a diver is really horrible, it is like a skiier that can't learn to ski, and all the instructors need to almost flip a coin to see who gets "stuck" babysitting the "Never-Ever". And there are some DM's that are often called for doing this, when a known horrific diver books on the boat. Personally, I would want no part of diving with this kind of person. Lately, whenever I see one of these, I tell them they should hire the well known, if not somewhat famous, Dumpster Diver to dive with them, the next time they dive here ...

 

[Bob DBF]

Jim, you have made this point before on this Board. I appreciate what you are saying.

However, I do want to point out that it would be very understandable if new divers were to feel that they are expected to follow a dive boat's DM. Dive boats are not dcemocratic instituions. There's a captain. Divers are expected to follow the directions of the crew.

First, I don't believe that OW divers should be trained to plan their own dives, not to follow a DM or Instructor blindly just because they are figures of authority.

Second, The DM changed the dive plan on the fly without finding out if it would create a problem, a trained proffessional in action.

Third, the Captain is in charge of his boat, the DM is in charge of showing you the pretty fishies, and you are in charge of your life. If this incident did not turn out as well as it did, the skipper and DM would be absolved of blame amd we would all be discussing what the OP did wrong, without any facts of course.



Bob
----------------------------------
I may be old, but I’m not dead yet.

"the future is uncertain and the end is always near"
Jim Morrison

 

[boulderjohn]

Biggest items I see here are the following:
1. Do not trust a DM to stick to a dive plan, plan a dive, or keep you safe. In fact rely on them only for a site briefing. Then plan your own dive and stick to that.

I have been on a number of dive boats on which the DM effective says, "Follow me; we are going dowon to _____ ." It is understandable if divers believe that they are required to follow the DM under such circumstances.

Personally, I hate doing that kind of diving. That's one reason that I love to dive the Florida Keys, where dive operators are less likely to do that.

In Palm Beach, the Dive Guide ( often a DM) gives the briefing, then anyone that "desires" to follow him or her, gets into the "group" following the Guide....He tows a float/flag so they don't need to worry about towing their own, or whether they will get to the best parts of the reef that the guide discusses he would be going to in the briefing..... If there were 20 divers on the boat, there might be 6 to 10 max that would decide to follow the guide...on some trips with mostly advanced divers, this could be the Dive Guide by himself or with one buddy
Of the divers that begin to follow the guide on a dive, if any of them see something they get interested in, and decide to spend more time looking at it, and the Dive Guide wants to keep going...they just stay....the guide swims away, and that is it. There is no concern by anyone over this, because the guide is only there as a potential tool to help find something you might like to see--the guide knows this, as do the divers.

Let's remember that this dive took place in Cozumel. Telling the diver how he should dive in Palm Beach (or somewhere else) is not going to be a lot of help. In Cozumel, divers within the marine park are required by law to follow a DM. This is drift diving without a surface flag, so the divers have to stay together to be found by the boat at the end of the dive. I cannot even begin to estimate the number of divers over the years who have lost touch with the group on a dive in Cozumel, never to be seen again. I only knew two of them personally (RIP), but there have been many more. Ignoring the DM and doing whatever you like is not a god idea there, and it is against the law.

I have been in many places throughout the world where there is no DM in the water, and you just do what you want. I have been in many places where there is an optional DM. I have been in many places where the DM is mandatory--you are not allowed to do anything but follow the DM. I have been in some areas where what you did was based on a particular site--there are places where you are guaranteed to be lost if you don't follow the experienced DM. You don't do the same thing on every dive regardless of the situation. You do what is appropriate wherever you are.

I am also surprised by the idea of never deviating from a dive plan. One time I was in a group starting a dive with a clear plan off the big island in Hawai'i. We were still near the surface heading for our descent point when we looked below and saw a huger manta ray getting serviced in a cleaning station. We immediately abandoned our much more mundane plan and descended to take in that sight. Eventually the manta took off, and we were about to do the same when an eagle ray showed up for a cleaning. After a while we started our ascent up the reef, where we saw another great sight, and then another. It turned out to be one of the best dives of my life, a dive that we would have missed completely if we had insisted on our original plan. I don't see anything wrong with it, and you "plan your dive and dive your plan" purists can hurl all the insults you want at me--you will get no apology for it.

I will bet that the Cozumel DM had a specific dive plan in mind, leading divers to specific sites along the way. Columbia Deep is my favorite site in Cozumel--one of my favorite in the world, in fact. There are some great places to go. The last time I was there (this past September), it was an extremely disappointing dive because the DM was forced by circumstances to skip some of the best parts of the dive. The rest of the group was totally unaware of this--they only know where they went and thought it was a great dive. Because I knew the site well enough, I knew what we missed, and I was frustrated that the DM did not do a better job of manipulating the circumstances. I have often seen DMs in Cozumel take steps to avoid other dive groups--it is something I expect them to do. Consequently, I have no qualms with the concept of a DM making a change based on circumstances, although in this case he apparently expected too much of his dive group and should have done something different.

 

[danvolker]

Let's remember that this dive took place in Cozumel. Telling the diver how he should dive in Palm Beach (or somewhere else) is not going to be a lot of help. In Cozumel, divers within the marine park are required by law to follow a DM. This is drift diving without a surface flag, so the divers have to stay together to be found by the boat at the end of the dive. I cannot even begin to estimate the number of divers over the years who have lost touch with the group on a dive in Cozumel, never to be seen again. I only knew two of them personally (RIP), but there have been many more. Ignoring the DM and doing whatever you like is not a god idea there, and it is against the law.

I have been in many places throughout the world where there is no DM in the water, and you just do what you want. I have been in many places where there is an optional DM. I have been in many places where the DM is mandatory--you are not allowed to do anything but follow the DM. I have been in some areas where what you did was based on a particular site--there are places where you are guaranteed to be lost if you don't follow the experienced DM. You don't do the same thing on every dive regardless of the situation. You do what is appropriate wherever you are.

I am also surprised by the idea of never deviating from a dive plan. One time I was in a group starting a dive with a clear plan off the big island in Hawai'i. We were still near the surface heading for our descent point when we looked below and saw a huger manta ray getting serviced in a cleaning station. We immediately abandoned our much more mundane plan and descended to take in that sight. Eventually the manta took off, and we were about to do the same when an eagle ray showed up for a cleaning. After a while we started our ascent up the reef, where we saw another great sight, and then another. It turned out to be one of the best dives of my life, a dive that we would have missed completely if we had insisted on our original plan. I don't see anything wrong with it, and you "plan your dive and dive your plan" purists can hurl all the insults you want at me--you will get no apology for it.

I will bet that the Cozumel DM had a specific dive plan in mind, leading divers to specific sites along the way. Columbia Deep is my favorite site in Cozumel--one of my favorite in the world, in fact. There are some great places to go. The last time I was there (this past September), it was an extremely disappointing dive because the DM was forced by circumstances to skip some of the best parts of the dive. The rest of the group was totally unaware of this--they only know where they went and thought it was a great dive. Because I knew the site well enough, I knew what we missed, and I was frustrated that the DM did not do a better job of manipulating the circumstances. I have often seen DMs in Cozumel take steps to avoid other dive groups--it is something I expect them to do. Consequently, I have no qualms with the concept of a DM making a change based on circumstances, although in this case he apparently expected too much of his dive group and should have done something different.

Good post John. So either the divers that might not be able to keep up with an errant DM should dive Palm Beach instead( for more intelligent diving practices), OR, they should get slick bp/wing systems, lose all the danglies with DIR rigging, and get carbon fiber or composite freediving fins, so that they will be faster and far more efficient at high speed than the Dive Masters of Cozumel. Also, they could ride a bike or standing bike 3 times per week for 20 to 40 minutes, at what is an aerobic pace for them.....or do a cycling interval workout for 40 minutes if they are in to doing what is optimal, but a little more challenging
It should not be hard to be faster or at least keep up with a DM, especially if your gear is slicker and better at high speeds than theirs is

 

[boulderjohn]

Good post John. So either the divers that might not be able to keep up with an errant DM should dive Palm Beach instead( for more intelligent diving practices), OR, they should get slick bp/wing systems, lose all the danglies with DIR rigging, and get carbon fiber or composite freediving fins, so that they will be faster and far more efficient at high speed than the Dive Masters of Cozumel. )

I have never seen a DM in Cozumel go too fast for anyone. This report is quite surprising for that reason. They are usually quite obsessive about keeping the group together. The only exceptions are when you have an extremely skilled group. In such cases the DM does not go fast, but he or she will not be quite so obsessive about the group and will allow more diver freedom to explore.

I have had to work very hard on some Cozumel dives, though. For example, I was on a dive on Barracuda Reef where the current was ripping diagonally between the peaks so hard that it took all we had to stay on the reef at those points. That is why dive operators will not take you to Barracuda Reef unless you have the skills for it, and some operators will not take anyone there.

---------- Post added January 15th, 2013 at 10:10 AM ----------

Good post John. So either the divers that might not be able to keep up with an errant DM should dive Palm Beach instead( for more intelligent diving practices),

If I were a dive operator in Cozumel and following a DM were not the law, I would still require it of my DMs. Under those circumstances, I believe it really is an intelligent diving practice for that location.

I have never dived WPB, but I have a lot of dives just south of that (Hillsborough, Pompano Beach, Ft. Lauderdale, etc.) . I have never seen a DM in the water there, and I have never seen the need for one. The two sites are nowhere near alike, so what is intelligent in one location would be downright stupid in another.

Maybe I will give WPB a shot in February.

 

[danvolker]

I have never seen a DM in Cozumel go too fast for anyone. This report is quite surprising for that reason. They are usually quite obsessive about keeping the group together. The only exceptions are when you have an extremely skilled group. In such cases the DM does not go fast, but he or she will not be quite so obsessive about the group and will allow more diver freedom to explore.

I have had to work very hard on some Cozumel dives, though. For example, I was on a dive on Barracuda Reef where the current was ripping diagonally between the peaks so hard that it took all we had to stay on the reef at those points. That is why dive operators will not take you to Barracuda Reef unless you have the skills for it, and some operators will not take anyone there.

---------- Post added January 15th, 2013 at 10:10 AM ----------



If I were a dive operator in Cozumel and following a DM were not the law, I would still require it of my DMs. Under those circumstances, I believe it really is an intelligent diving practice for that location.

I have never dived WPB, but I have a lot of dives just south of that (Hillsborough, Pompano Beach, Ft. Lauderdale, etc.) . I have never seen a DM in the water there, and I have never seen the need for one. The two sites are nowhere near alike, so what is intelligent in one location would be downright stupid in another.

Maybe I will give WPB a shot in February.

If you are a local Palm Beach diver, you consider the Pompano area and South of that to be "still water" diving. The Gulf Stream comes much closer to the reefs in Palm Beach ( Boynton/Delray; Breakers; Juno/Jupiter) than it does off of Broward County... Even on the 280 foot deep wrecks off of Pompano and Lauderdale ( much farther out than the 60 foot deep reefline) there is so little current that many will anchor dive these wrecks.....a practice not feasible even on the baby reefs of Boynton in 40 feet of water, lot less on the deeper wrecks here.

Hopefully you can make it here sometime to dive... If so, I'll get you on the short list of my favorite dive sites here !

 

[boulderjohn]

If you are a local Palm Beach diver, you consider the Pompano area and South of that to be "still water" diving. The Gulf Stream comes much closer to the reefs in Palm Beach ( Boynton/Delray; Breakers; Juno/Jupiter) than it does off of Broward County... Even on the 280 foot deep wrecks off of Pompano and Lauderdale ( much farther out than the 60 foot deep reefline) there is so little current that many will anchor dive these wrecks.....a practice not feasible even on the baby reefs of Boynton in 40 feet of water, lot less on the deeper wrecks here.

The difference is not just the currents--the coral structures are the key. When drift diving in your area, dive flags are required, a ruling made possible by the structure of the terrain. A boat can keep a careful eye on the dive flags as they move along and then pick up divers as they surface. There is nothing between the diver and the surface to interfere with the progress of the float line.

In Cozumel, the towering coral structures, sometimes 100 feet above you as you dive, make dive flags/floats impossible. They would snag constantly above you, breaking off coral and sponge as you try to move. Nothing is sent to the surface until the final ascent, at which point the group surfaces next to the SMB to be picked up by the trailing boat. The trailing boat has nothing but the group's bubbles to follow during the drift. If all the divers on the boat instead separated into widely separated buddy teams, the boat would have a seriously difficult task finding all of them at the end of the dive.That is especially true because on the popular sites, dive teams would intermingle, and people would be popping up allover the place. Divers would be lost there every day.

IHopefully you can make it here sometime to dive... If so, I'll get you on the short list of my favorite dive sites here !

Maybe in a few weeks.

 

[danvolker]

The difference is not just the currents--the coral structures are the key. When drift diving in your area, dive flags are required, a ruling made possible by the structure of the terrain. A boat can keep a careful eye on the dive flags as they move along and then pick up divers as they surface. There is nothing between the diver and the surface to interfere with the progress of the float line.

In Cozumel, the towering coral structures, sometimes 100 feet above you as you dive, make dive flags/floats impossible. They would snag constantly above you, breaking off coral and sponge as you try to move. Nothing is sent to the surface until the final ascent, at which point the group surfaces next to the SMB to be picked up by the trailing boat. The trailing boat has nothing but the group's bubbles to follow during the drift. If all the divers on the boat instead separated into widely separated buddy teams, the boat would have a seriously difficult task finding all of them at the end of the dive.That is especially true because on the popular sites, dive teams would intermingle, and people would be popping up allover the place. Divers would be lost there every day.

Maybe in a few weeks.

I agree the structure would invalidate the primary model of Palm Beach drift diving, though many of the PB boats that "cater" to advanced divers they know (locals), drop the buddy teams without flags ----- and between following bubble trails, and pretty much knowing where the divers will be in 30 minutes, and so on, the boat is typically damn close at the near end of the dive, when the buddy teams are doing safety stops, and have deployed their SMB's. This practice would work fine for us Palm Beach divers should we want to go to cozumel, assuming we could find a Captain their competent enough to work with us on what we wanted to do...