ajduplessis
Contributor
I assume you wanted to say DCI
Can Deco-Sickness occur during the dive?
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I assume you wanted to say DCI
DevonDiver
N/A
If oxygen toxicity occurs underwater, the cause of death is drowning. The toxicity causes the diver to enter convulsions (like an epileptic fit). During those convulsions the diver will lose their regulator, inhale water and drown. It is rarely survivable.
The occurrence of oxygen toxicity can happen for two reasons:
1) It can be due to the high partial pressure of oxygen breathed at depth. This is known as CNS (central nervous system) toxicity. This is the 'killer'.
2) It can be caused by prolonged/repeated exposure to high oxygen partial pressures over repeated dives. This is know as pulmonary oxygen toxicity. Pulmonary toxicity is much more rare and results in lung irritation and/or breathing difficulties. Typically this is only a concern for technical divers using very high percentage oxygen mixtures for decompression, several times a day, for several days. Those diver track their overall exposure using OTU (oxygen toxicity units) to ensure they avoid pulmonary toxicity complications.
For CNS Toxicity, most diving agencies recognise that an oxygen partial pressure limit of 1.4ppO2 is the maximum safe boundary. However, 1.6ppO2 is frequently used by technical divers for the purposes of decompression using rich oxygen nitrox mixtures. This is permitted because divers conducting decompression are very static and restful. Oxygen toxicity is exacerbated by CO2 levels and/or exertion - so any activity whilst breathing high oxygen partial pressure gas increases the likelihood of convulsions.
Breathing Air, 1.4ppO2 is achieved at 56.6m/185ft. So... it's not something your fictitious diver would have to worry about. This depth is also well below the maximum depth to which even very experienced, highly trained, recreational divers are qualified to go (that being 40m/130ft).
However, CNS Oxygen Toxicity is the major killer for technical and rebreather divers. This is because those divers use much higher percentage oxygen mixtures - which become toxic at much shallower depths. If a technical diver accidentally breathed from their 'rich oxygen' deco mix at the wrong stage of their dive, then oxygen toxicity would be highly likely. Likewise, rebreather divers rely on electronic control of oxygen input into their breathing loop - if their equipment malfunctions and delivers too much oxygen it will cause toxicity. However, both groups of divers have a range of procedures designed to allow them to avoid this mishap. Sometimes they just get unlucky or careless... and ox-tox is very unforgiving of such mistakes.
Oxygen toxicity is rarely preceded by any obvious symptoms. It typically strikes without warning. On rare occasions, a diver may notice some symptoms before the seizures occur - which gives them a small chance to quickly abort the dive and prevent the toxicity. Divers are taught that these symptoms are:
Convulsions,
Visual disturbances,
Ear disturbances,
Nausea,
Twitching,
Irritability,
Dizziness.
Obviously Oxtox can't be applied to this dive :| but I thank you for the explanation anyway.
SO back to the deco sickness theory.
Say the diver was into the second dive and had reached 70ft, experienced tingling sensations in fingers, hurting joints, and began to panic. Out of panic, the diver began to swim to the top recklessly causing NCS to develop at a more dangerous level. Upon surfacing, the diver fell unconscious and could not be resuscitated?
^^Is that how it'd work?
Just as a side note, if the mixture was ean36, where the po2 is slightly above 1.4, is there any way to calculate likelihood or risk?
Can i also ask, what percentage of CNS loading is lethal?
I was trying to teach it to someone but obviously I'm learning more than teaching.
SO back to the deco sickness theory.
Say the diver was into the second dive and had reached 70ft, experienced tingling sensations in fingers, hurting joints, and began to panic. Out of panic, the diver began to swim to the top recklessly causing NCS to develop at a more dangerous level. Upon surfacing, the diver fell unconscious and could not be resuscitated?
^^Is that how it'd work?
Just as a side note, if the mixture was ean36, where the po2 is slightly above 1.4, is there any way to calculate likelihood or risk?
Can i also ask, what percentage of CNS loading is lethal?
I was trying to teach it to someone but obviously I'm learning more than teaching.
Bubbletrubble
Contributor
Please define the term "NCS." I'm not familiar with that abbreviation. Perhaps you transposed the letters and meant to write "CNS," which stands for "central nervous system."
Could you please elaborate a little on what you are asking?
Are you wondering whether the scenario you described could happen?
Panicked divers can do any number of unpredictable things. They are particularly prone to making rapid, uncontrolled ascents which can lead to arterial gas embolism (AGE). AGE is associated with a variety of CNS symptoms. There have been a number of dive fatality reports that involve the victim surfacing with a loss of consciousness.
Likelihood or risk of what? DCS? Death? Oxygen toxicity?
I'm a little confused as to why you are asking about EAN36 mix being breathed by a diver at a depth that places the ppO2 at slightly higher than 1.4.
Mentioning those details in that way leads me to believe that you are getting nitrogen-loading confused with oxygen exposure. They are two separate concepts. (See DevonDiver's explanation of oxygen toxicity above.) With regard to oxygen toxicity, a recommended limit of 1.4 is given for ppO2, but I would regard it as nothing more than a rule of thumb. It is thought that as the ppO2 climbs higher than the 1.4-1.6 range, the likelihood of oxygen toxicity increases. The reality is that we really don't know on a physiological level what is causing the CNS clinical manifestations of oxygen toxicity. Some people may be more susceptible than others. An individual might be more susceptible from one day to the next. Oxygen toxicity is rather rare in even technical divers. This makes it quite difficult to come up with numerical risk of oxygen toxicity.
This is another odd question. Even though you didn't specify whether you're talking about nitrogen loading or oxygen exposure, it probably wouldn't matter anyway since we don't understand either phenomena enough to assign lethality statistics.
We can post all day back and forth trying to explain the ins and outs of DCS risk and oxygen toxicity...
...or you can just get scuba certified, take a nitrox class, and then supplement that fund of knowledge with some outside reading.
He wouldn't experience any symptoms of dcs while at his max depth.
Your original question was "can dcs occur during the dive?" The answer is yes. However, if it does, it would be while decompressing at relatively shallow depth towards the end of the dive. This is also much more likely to happen if the bottomgas was a heliumbased gas. Helium is a much faster gas than nitrogen and will diffuse both in and out of tissues about 2,7 times faster than nitrogen. It does take some time for the dissolved gas to come out of solution, form bubbles and bend you. Hence the delay of symptoms, and hence the faster onset of symptoms after a heliumdive.
If memory serves me, about 80% of dcs cases manifests themselves within the first 60 min of surfacing, even with nitrogen as the only inertgas. With heliumbased gasses, the onset is even quicker, and often manifests itself very shortly after surfacing or even while still in the water decompressing.
Severe cases of dcs is very rarely delayed more than an hour. Lung overexpansion injuries manifests itself shortly after surfacing, and have more or less the same effect as the most severe cases of dcs.
A way your diver could very well get himself into big trouble even on these dives, would be due to bubbles formed on the first dive that would be compressed on the second, take on even more nitrogen, and due to the compression be able to pass the lungs and then re-expand on the arterial side of your circulatory system.
As a rule of thumb, the more important a tissue is (ie. brain, central nerveous system.....), the more direct they will receive blood, oxygen but unfortunately also arterial bubbles. As such this latter form of dcs can very well be a severe one.
Richard Pyle had a very nasty dcs case on a dive not all that different from this one.
Best,
Bjørn
DevonDiver
N/A
Indeed. Typo. What I meant was... "You would probably get deco from a missed DCI stop".
Nope. Bubbles form when the ambient pressure surround the diver decreases (on ascent). The pressure at depth would keep/return the nitrogen in suspension within his body, thus no DCI symptoms. If there were bubbles already in existence (from the first dive) then the surrounding pressure would 'crush' those bubbles to a smaller size (Boyle's Law) - reducing the symptoms they provoked whilst the diver remained at depth.
Even if the diver was symptomatic of DCI after the first dive, when he re-descended for the second dive, those symptoms would most likely subside. However, during that second dive, more nitrogen is absorbed into pre-existing (but crushed) bubbles, meaning that the DCI symptoms would re-occur again on ascent (at the surface) and would be more severe.
Apart from the cause of the panic ascent (diver wouldn't feel symptomatic on the dive), then yes. However, that'd be a very rare and severe case of DCI given the dive profile you stated.
If you want to know about 'death from DCI'... read Robert Kurson's 'Shadow Divers'.... in particular the sequence that describes the deaths of Chris Rouse and Chris Rouse Jr. However, their deaths arose from considerablydeeper and longer dives than you have theorised. It is quite a harrowing description to read.
Not really. The figure of 1.4ppO2 has evolved through statistical analysis of ox-tox events/accidents. 1.4ppO2 is believed to be a highly safe level to dive at... virtually guaranteeing that divers won't ox-tox from CNS toxicity. The limitation is designed to keep divers safe. Ox-tox is one of those "on any given day" risks. There are also a wide variety of factors that are theorised to make divers more or less susceptible to toxicity, including physiology, exertion/CO2 retention and even the potential of 'CNS inhibition' due to inert gas narcosis at deeper depths.
Basically, it can happen and if it does, it is probably going to kill you - because it's hard to survive convulsion/drowning when you are deep under water. That's enough for the diving community to set a very low boundary on oxygen partial pressure.
As mentioned, CNS toxicity is determined by partial pressure. Exceed the ppO2 and you can have immediate convulsions. It's hit or miss. Convulsions mean you'll drown. If you drown at 100ft or deeper... there is a very low likelihood that you can be raised to the surface and resuscitated quickly enough to prevent brain damage of death. Brain damage is almost certain after 6 minutes (likely after 3mins) and death is almost certain after 10 minutes. Even if a rescuer was immediately on-hand when you convulsed, they'd have to raise you from that depth before they could begin first-aid/resuscitation. That'd take them 3+ minutes at a safe ascent rate. Upon surfacing they could start rescue breathing in the water. However, if the heart had stopped (highly likely after 3+ minutes without respiration), they couldn't begin with full CPR until the diver was out of the water. Getting the diver to the shore/boat, out of their kit and ready for CPR is likely to take several more minutes.
The timeline for rescuing a ox-tox casualty is definitely not in the victim's favour.
DevonDiver
N/A
Further to my last post, here is an excerpt from Shadow Divers, that describes the incident that caused the deaths of two divers (Chris Rouse and his son). It's a true event. Note that the depth and duration of this dive are far more significant than the hypothetical dive outlined in this thread - thus the DCI severity is far more serious than would be expected in the scenario we are discussing. It does, however, provide an example of how severe/fatal DCI would manifest - and how it would be dealt with by the rescuers.
Dive details:
Dive Site: U-869, (German U-boat) Eastern USA
Depth: 73m / 240ft
Planned dive time: 20 minutes – delay caused ~40 minutes bottom-time.
Planned deco/ascent time: 60 minutes, delay on bottom extended this to ~150 minutes.
Incident details: Chris Rouse Jr became trapped inside the U-Boat, causing an extensive delay at the bottom. Upon freeing himself from the wreck, the divers were disorientated and could not retrieve the cylinders containing their deco gas (which had been left outside of the wreck, due to tight spaces). Due to insufficient gas and panic, both divers conducted rapid ascent, missing all deco stops.
- Excerpt from 'Shadow Divers' by Robert Kurson -
Inside the Seeker’s wheelhouse, Chatterton, Kohler, and Crowell checked the weather and shivered—brutal seas and nasty winds were rolling in. A minute later they saw two divers pop to the surface about a hundred feet in front of the boat. Chatterton looked closer. He saw the hockey-type helmets of the Rouses. They had come up an hour ahead of schedule.
“Oh, Christ,” Chatterton said. “This ain’t good.”
Chatterton and Kohler tore down the wheelhouse steps and onto the Seeker’s bow. Chatterton raised his arm and put his fingertips on his head, the universal “Are you okay?” signal to divers. Neither man responded.
Six-foot waves threw the divers closer to the boat. Chatterton and Kohler looked into the men’s faces. Both father and son had the wide, rapidly blinking eyes of the newly condemned.
“Did you complete your decompression?” Chatterton yelled. Neither diver answered.
“Swim to the boat!” Chatterton yelled.
Chrissy moved his arms and inched closer to the Seeker. Chris also tried to swim, but he flopped sideways and half-kicked like a sick goldfish.
“Chrissy! Did you complete your decompression?” Chatterton pressed.
“No,” Chrissy managed to yell back.
“Did you come straight to the surface?”
“Yes,” Chrissy said.
Kohler went ashen at the answer. He remembered the Atlantic Wreck Divers’ mantra: I would rather slit my throat than shoot to the surface without decompressing.
Chatterton grabbed two throw lines to fling to the Rouses. The Seeker rose and fell on the raging waves like a carnival ride, each undulation threatening to launch Chatterton and Kohler into the Atlantic. An eight-foot wave pushed Chrissy under the Seeker as her bow lifted off the ocean like an executioner’s ax. The Seeker fell from the darkening sky, Chrissy helpless to move away. Chatterton and Kohler held their breath. The boat’s splash rail hurtled downward and bashed the regulator on Chrissy’s tanks, just inches from his skull, splitting the brass mechanism and releasing an explosion of rushing air from the tanks. Chatterton threw the lines. Each of the Rouses managed to grab a rope. Chatterton and Kohler pulled the divers along the side of the boat, towing them out from under the Seeker and toward the stern. Crowell ran into the wheelhouse.
He radioed the Atlantic City Coast Guard repeatedly but got no reply.
“F*%k this,” he thought to himself. “I’m calling a Mayday.”“Mayday! Mayday! Mayday!” Crowell called into his handheld microphone. “This is the vessel Seeker. Requesting immediate helicopter evacuation. We have injured divers. Please acknowledge.” The Brooklyn Coast Guard station responded. They were sending a chopper. Chatterton, Kohler, and other divers continued to tow the Rouses toward the back of the boat as the Seeker’s bow rose and fell with thunderous booms. Chris came around nearest the ladder. Chatterton rushed toward him.
“Chris, get up the ladder!” Chatterton yelled.
“Take Chrissy first,” Chris grunted.
Chatterton began to insist but stopped himself when he looked into Chris’s widened eyes. In them, he saw only fear and knowing—the kind of knowing that occurs when one’s fate is certain and moments away.
“Okay, Chrissy, come up!” Chatterton yelled to the younger Rouse, who was holding on to a line about ten feet behind his father.
The divers pulled Chrissy to the ladder. He screamed in pain.
“I can’t move my legs!” Chrissy yelled. “Monkeyf*%k! Monkeyf*%k! It hurts! It hurts so bad!”
Chatterton knew that serious decompression bends were already upon the divers. He and Kohler straddled the gunwale on either side of the ladder and put their arms under Chrissy, grabbing the underside of his tanks for leverage. The Seeker rose and fell with nature’s onrushing tantrum, each explosion against the ocean threatening to catapult the divers overboard and crush Chrissy under the stern. The lactic acid in Chatterton’s and Kohler’s muscles burned as they willed themselves to hang on to the stricken young diver. Between impacts, they managed to lug Chrissy up the ladder until he thudded onto the deck like a netted tuna.
“Get him onto the dressing table!” Chatterton ordered. Kohler and others dragged Chrissy to the table and began cutting off his gear. Barb Lander, a nurse by profession, force-fed Chrissy aspirin and water and put an oxygen mask over his face.
“I f*%ked up, I f*%ked up, I f*%ked up!” Chrissy yelled. “I can’t move my legs!”
Lander cradled his head.
“You’re okay, Chrissy,” she said. “You’re on the Seeker now.”
Chrissy thrashed and screamed and tried to tear the oxygen mask from his face.
“I can’t breathe!” he screamed. “I’m burning! A monster pinned me! I was trapped!”
At the ladder, Chatterton turned his attention to Chris.
“Chris! Chris! Come on, you’re next. You can do it! Let’s go!” Chatterton yelled.
Chris looked into Chatterton’s eyes.“I’m not going to make it,” he said. “Tell Sue I’m sorry.”
Chris’s chin dropped to his chest and his head flopped into the water. Chatterton and Kohler, both dressed in street clothes, leaped into the freezing ocean. Chatterton lunged for Chris’s head and lifted it into the air.
“Get me a knife!” Chatterton yelled.
The Seeker bashed up and down in the Atlantic, hurling Chatterton and Kohler underwater. When the boat rose, Chatterton yelled, “I gotta cut his rig off!”
Kohler pointed to a knife sheathed on Chris’s shoulder. Chatterton grabbed it and slashed at the diver’s harness until Chris’s rig fell away. Chatterton then muscled Chris into a fireman’s carry and brought him up the ladder, straining to hang on as the Seeker heaved and exploded into the ocean and sent salt water spraying into the men’s eyes. Kohler looked inside Chris’s mask, praying to see more dread because dread would mean that Chris was still alive. Chris only stared straight ahead. The men dragged him onto the Seeker’s deck, his fins sloshing along the sea-soaked wood. Chatterton began CPR on the elder Rouse.
For a few moments, Chris did not respond to Chatterton’s efforts. His skin began to turn blue. Kohler murmured, “Come on, Chris, don’t let go . . . don’t let go . . . don’t let go . . .” Chatterton kept relentlessly at his CPR. Suddenly, Chris threw up into Chatterton’s mouth, and Chatterton could taste the Pepsi he and Chris had shared that morning. Kohler sprang to his feet, hopeful that the vomiting indicated revival. Chatterton looked up at Kohler with eyes from 1970 Vietnam.
“Richie, go in the wheelhouse,” Chatterton said with a calm that seemed to Kohler to mute the raging ocean. “Get pencil and paper. Write down times and events. Be sure to get everything Barb’s doing on that table and everything Chrissy is saying. Make sure she gets vital signs on him. Record everything. We’ll need to send this information with the Coast Guard.”
Chatterton continued the CPR, but with each compression he felt increasing resistance, evidence that Chris’s blood was turning to foam and clotting in his body. After five minutes, Chris’s heart stopped and his skin turned from blue to coal gray. The whites of his eyes were bloody. Chatterton knew he was dead. He kept pumping anyway. You did not give up on a human being just because he was dead.
At the dressing table, Lander pushed Chrissy’s long brown hair out of his face and held his head in her lap as he writhed and screamed and drifted in and out of lucidity.
“The monster got me!” he screamed. “A monster pinned me. Monkeyf*%k! It was a monkeyf*%k!”
Kohler bit his bottom lip and took notes.“My father! How is my father?” Chrissy asked.
Kohler and Lander looked toward Chatterton as he pumped away on Chris’s lifeless body. They knew Chris had died.
“John’s with your father,” Kohler told him. “He’s on oxygen. He’s gonna be fine. Hang in, Chrissy. Can you tell me what happened?”
Chrissy went calm and for a moment spoke with a crystalline mind. He told Kohler that something had fallen and pinned him inside the wreck, that his father had come in and freed him, and that while they were ascending he had run out of air. Then, just as quickly, Chrissy spiraled back into delirium.
“I was in the wreck and f*%k this! I’m cold! I’m hot! I can’t feel my legs!” Lander stroked his head.
“Please shoot me!” Chrissy begged. “It hurts so bad. Someone find a gun and shoot me. Please kill me. Dad! Dad!”
For the next ninety minutes, Chatterton and others continued CPR on Chris’s dead body. Crowell, who had cut the anchor line, headed thirty degrees into the wind as instructed by the Coast Guard, then began a head count. Each diver called out, “Here.” Crowell dropped the Seeker’s antennas to allow the helicopter to approach unobstructed. He ordered everyone into life jackets, then demanded that any loose items be moved into the salon or secured to the deck; the helicopter’s prop wash could turn a loose face mask into a deadly missile or suck up a sleeping bag into its rotors and crash.
On the horizon, the divers could see the orange-and-white Coast Guard chopper speeding toward them…
….It took twenty minutes to load Chris onto the chopper. After both Rouses were aboard, the helicopter lowered the basket a final time for the swimmer. The jet engines screamed as the chopper swooped away and raced toward the recompression chamber at Jacobi Medical Center in the Bronx.
One by one the divers made their way from the salon and toward Chatterton. Each thanked him or hugged him. Everyone knew that Chris was dead. Everyone believed Chrissy would make it.
The trip back to Brielle was somber but hopeful. Hospital recompression could take hours; the divers hoped to get word of Chrissy’s condition by the next morning. The metal schematic, which had held so much promise and which had brought such optimism, lay forgotten, wrapped in a towel in a Tupperware container.
That evening Lander called Chatterton at home
.“Chrissy didn’t make it,” she said. “He died in the chamber.”Chatterton put down the receiver.
-End Excerpt -
Dive details:
Dive Site: U-869, (German U-boat) Eastern USA
Depth: 73m / 240ft
Planned dive time: 20 minutes – delay caused ~40 minutes bottom-time.
Planned deco/ascent time: 60 minutes, delay on bottom extended this to ~150 minutes.
Incident details: Chris Rouse Jr became trapped inside the U-Boat, causing an extensive delay at the bottom. Upon freeing himself from the wreck, the divers were disorientated and could not retrieve the cylinders containing their deco gas (which had been left outside of the wreck, due to tight spaces). Due to insufficient gas and panic, both divers conducted rapid ascent, missing all deco stops.
- Excerpt from 'Shadow Divers' by Robert Kurson -
Inside the Seeker’s wheelhouse, Chatterton, Kohler, and Crowell checked the weather and shivered—brutal seas and nasty winds were rolling in. A minute later they saw two divers pop to the surface about a hundred feet in front of the boat. Chatterton looked closer. He saw the hockey-type helmets of the Rouses. They had come up an hour ahead of schedule.
“Oh, Christ,” Chatterton said. “This ain’t good.”
Chatterton and Kohler tore down the wheelhouse steps and onto the Seeker’s bow. Chatterton raised his arm and put his fingertips on his head, the universal “Are you okay?” signal to divers. Neither man responded.
Six-foot waves threw the divers closer to the boat. Chatterton and Kohler looked into the men’s faces. Both father and son had the wide, rapidly blinking eyes of the newly condemned.
“Did you complete your decompression?” Chatterton yelled. Neither diver answered.
“Swim to the boat!” Chatterton yelled.
Chrissy moved his arms and inched closer to the Seeker. Chris also tried to swim, but he flopped sideways and half-kicked like a sick goldfish.
“Chrissy! Did you complete your decompression?” Chatterton pressed.
“No,” Chrissy managed to yell back.
“Did you come straight to the surface?”
“Yes,” Chrissy said.
Kohler went ashen at the answer. He remembered the Atlantic Wreck Divers’ mantra: I would rather slit my throat than shoot to the surface without decompressing.
Chatterton grabbed two throw lines to fling to the Rouses. The Seeker rose and fell on the raging waves like a carnival ride, each undulation threatening to launch Chatterton and Kohler into the Atlantic. An eight-foot wave pushed Chrissy under the Seeker as her bow lifted off the ocean like an executioner’s ax. The Seeker fell from the darkening sky, Chrissy helpless to move away. Chatterton and Kohler held their breath. The boat’s splash rail hurtled downward and bashed the regulator on Chrissy’s tanks, just inches from his skull, splitting the brass mechanism and releasing an explosion of rushing air from the tanks. Chatterton threw the lines. Each of the Rouses managed to grab a rope. Chatterton and Kohler pulled the divers along the side of the boat, towing them out from under the Seeker and toward the stern. Crowell ran into the wheelhouse.
He radioed the Atlantic City Coast Guard repeatedly but got no reply.
“F*%k this,” he thought to himself. “I’m calling a Mayday.”“Mayday! Mayday! Mayday!” Crowell called into his handheld microphone. “This is the vessel Seeker. Requesting immediate helicopter evacuation. We have injured divers. Please acknowledge.” The Brooklyn Coast Guard station responded. They were sending a chopper. Chatterton, Kohler, and other divers continued to tow the Rouses toward the back of the boat as the Seeker’s bow rose and fell with thunderous booms. Chris came around nearest the ladder. Chatterton rushed toward him.
“Chris, get up the ladder!” Chatterton yelled.
“Take Chrissy first,” Chris grunted.
Chatterton began to insist but stopped himself when he looked into Chris’s widened eyes. In them, he saw only fear and knowing—the kind of knowing that occurs when one’s fate is certain and moments away.
“Okay, Chrissy, come up!” Chatterton yelled to the younger Rouse, who was holding on to a line about ten feet behind his father.
The divers pulled Chrissy to the ladder. He screamed in pain.
“I can’t move my legs!” Chrissy yelled. “Monkeyf*%k! Monkeyf*%k! It hurts! It hurts so bad!”
Chatterton knew that serious decompression bends were already upon the divers. He and Kohler straddled the gunwale on either side of the ladder and put their arms under Chrissy, grabbing the underside of his tanks for leverage. The Seeker rose and fell with nature’s onrushing tantrum, each explosion against the ocean threatening to catapult the divers overboard and crush Chrissy under the stern. The lactic acid in Chatterton’s and Kohler’s muscles burned as they willed themselves to hang on to the stricken young diver. Between impacts, they managed to lug Chrissy up the ladder until he thudded onto the deck like a netted tuna.
“Get him onto the dressing table!” Chatterton ordered. Kohler and others dragged Chrissy to the table and began cutting off his gear. Barb Lander, a nurse by profession, force-fed Chrissy aspirin and water and put an oxygen mask over his face.
“I f*%ked up, I f*%ked up, I f*%ked up!” Chrissy yelled. “I can’t move my legs!”
Lander cradled his head.
“You’re okay, Chrissy,” she said. “You’re on the Seeker now.”
Chrissy thrashed and screamed and tried to tear the oxygen mask from his face.
“I can’t breathe!” he screamed. “I’m burning! A monster pinned me! I was trapped!”
At the ladder, Chatterton turned his attention to Chris.
“Chris! Chris! Come on, you’re next. You can do it! Let’s go!” Chatterton yelled.
Chris looked into Chatterton’s eyes.“I’m not going to make it,” he said. “Tell Sue I’m sorry.”
Chris’s chin dropped to his chest and his head flopped into the water. Chatterton and Kohler, both dressed in street clothes, leaped into the freezing ocean. Chatterton lunged for Chris’s head and lifted it into the air.
“Get me a knife!” Chatterton yelled.
The Seeker bashed up and down in the Atlantic, hurling Chatterton and Kohler underwater. When the boat rose, Chatterton yelled, “I gotta cut his rig off!”
Kohler pointed to a knife sheathed on Chris’s shoulder. Chatterton grabbed it and slashed at the diver’s harness until Chris’s rig fell away. Chatterton then muscled Chris into a fireman’s carry and brought him up the ladder, straining to hang on as the Seeker heaved and exploded into the ocean and sent salt water spraying into the men’s eyes. Kohler looked inside Chris’s mask, praying to see more dread because dread would mean that Chris was still alive. Chris only stared straight ahead. The men dragged him onto the Seeker’s deck, his fins sloshing along the sea-soaked wood. Chatterton began CPR on the elder Rouse.
For a few moments, Chris did not respond to Chatterton’s efforts. His skin began to turn blue. Kohler murmured, “Come on, Chris, don’t let go . . . don’t let go . . . don’t let go . . .” Chatterton kept relentlessly at his CPR. Suddenly, Chris threw up into Chatterton’s mouth, and Chatterton could taste the Pepsi he and Chris had shared that morning. Kohler sprang to his feet, hopeful that the vomiting indicated revival. Chatterton looked up at Kohler with eyes from 1970 Vietnam.
“Richie, go in the wheelhouse,” Chatterton said with a calm that seemed to Kohler to mute the raging ocean. “Get pencil and paper. Write down times and events. Be sure to get everything Barb’s doing on that table and everything Chrissy is saying. Make sure she gets vital signs on him. Record everything. We’ll need to send this information with the Coast Guard.”
Chatterton continued the CPR, but with each compression he felt increasing resistance, evidence that Chris’s blood was turning to foam and clotting in his body. After five minutes, Chris’s heart stopped and his skin turned from blue to coal gray. The whites of his eyes were bloody. Chatterton knew he was dead. He kept pumping anyway. You did not give up on a human being just because he was dead.
At the dressing table, Lander pushed Chrissy’s long brown hair out of his face and held his head in her lap as he writhed and screamed and drifted in and out of lucidity.
“The monster got me!” he screamed. “A monster pinned me. Monkeyf*%k! It was a monkeyf*%k!”
Kohler bit his bottom lip and took notes.“My father! How is my father?” Chrissy asked.
Kohler and Lander looked toward Chatterton as he pumped away on Chris’s lifeless body. They knew Chris had died.
“John’s with your father,” Kohler told him. “He’s on oxygen. He’s gonna be fine. Hang in, Chrissy. Can you tell me what happened?”
Chrissy went calm and for a moment spoke with a crystalline mind. He told Kohler that something had fallen and pinned him inside the wreck, that his father had come in and freed him, and that while they were ascending he had run out of air. Then, just as quickly, Chrissy spiraled back into delirium.
“I was in the wreck and f*%k this! I’m cold! I’m hot! I can’t feel my legs!” Lander stroked his head.
“Please shoot me!” Chrissy begged. “It hurts so bad. Someone find a gun and shoot me. Please kill me. Dad! Dad!”
For the next ninety minutes, Chatterton and others continued CPR on Chris’s dead body. Crowell, who had cut the anchor line, headed thirty degrees into the wind as instructed by the Coast Guard, then began a head count. Each diver called out, “Here.” Crowell dropped the Seeker’s antennas to allow the helicopter to approach unobstructed. He ordered everyone into life jackets, then demanded that any loose items be moved into the salon or secured to the deck; the helicopter’s prop wash could turn a loose face mask into a deadly missile or suck up a sleeping bag into its rotors and crash.
On the horizon, the divers could see the orange-and-white Coast Guard chopper speeding toward them…
….It took twenty minutes to load Chris onto the chopper. After both Rouses were aboard, the helicopter lowered the basket a final time for the swimmer. The jet engines screamed as the chopper swooped away and raced toward the recompression chamber at Jacobi Medical Center in the Bronx.
One by one the divers made their way from the salon and toward Chatterton. Each thanked him or hugged him. Everyone knew that Chris was dead. Everyone believed Chrissy would make it.
The trip back to Brielle was somber but hopeful. Hospital recompression could take hours; the divers hoped to get word of Chrissy’s condition by the next morning. The metal schematic, which had held so much promise and which had brought such optimism, lay forgotten, wrapped in a towel in a Tupperware container.
That evening Lander called Chatterton at home
.“Chrissy didn’t make it,” she said. “He died in the chamber.”Chatterton put down the receiver.
-End Excerpt -
I think I understand how it works.
That transcript is really sad btw. It doesnt relate to mine though
I realise now though that the DCS occurs after expansion. I really don' know how I missed that.
Ok so, lets try this again.
The diver dives with his friend to 100ft. He resurfaces ignoring the mandatory stop. Around 20 minutes into the 1hour surface interval, he experiences tingling sensations.
Ignoring them he goes for the second dive. Tingling stops at the bottom of the dive, on the way up it returns. Above the surface, excruciating pains within joints become apparent as well as Dizziness.
Just checked the Navy, the % frequency of collapse/unconciousness is 0.5% hmmmmm. So does tthat mean our diver's gonna live?
That transcript is really sad btw. It doesnt relate to mine though
I realise now though that the DCS occurs after expansion. I really don' know how I missed that.
Ok so, lets try this again.
The diver dives with his friend to 100ft. He resurfaces ignoring the mandatory stop. Around 20 minutes into the 1hour surface interval, he experiences tingling sensations.
Ignoring them he goes for the second dive. Tingling stops at the bottom of the dive, on the way up it returns. Above the surface, excruciating pains within joints become apparent as well as Dizziness.
Just checked the Navy, the % frequency of collapse/unconciousness is 0.5% hmmmmm. So does tthat mean our diver's gonna live?
| collapse/unconsciousness | 0.5% |
|---|
DevonDiver
N/A
Yep, that's what we've been trying to tell you.
Your theoretical dive isn't deep/long enough to pose substantial risk of lethality. Of course, any diver could get real unlucky... but the odds are minute.
If not treated promptly, that excruciating joint pain can cause long-term damage. Imagine the pain of a trapped nerve, or toothache... that's the sort of pain. Bubble compressing a nerve. It hurts. If not treated, the nerve can very easily get damaged, causing long-term/permanent immobility etc.
I don't know what the % frequency is, but there's a chance that bubbles could manifest in a critical nerve structure - causing organ failure. Likewise, bubbles could manifest in an organ itself. Rare.
Perhaps your theoretical diver gets a bubble in the lower spinal cord - causing permanent erectile dysfunction and loss of bladder control. Death would be feasible by suicide.
There's secondary issues also. Bubble formation triggers an immune response. The body 'sees' the bubbles as an invader - white blood cells swamp the bubble. This can cause complications or secondary risks, such as clots. If the clots then become mobile move into/within the vascular system, that can be potentially very dangerous. This is one of the reasons why hyperbaric treatment may include immuno-suppressant drugs.
If you are interested in getting more detailed medical feedback on these issues, just let me know via PM - I'll move the whole thread into the 'Dive Medicine' forum where our resident Diving MDs will shed a lot more light on the specifics.
Your theoretical dive isn't deep/long enough to pose substantial risk of lethality. Of course, any diver could get real unlucky... but the odds are minute.
If not treated promptly, that excruciating joint pain can cause long-term damage. Imagine the pain of a trapped nerve, or toothache... that's the sort of pain. Bubble compressing a nerve. It hurts. If not treated, the nerve can very easily get damaged, causing long-term/permanent immobility etc.
I don't know what the % frequency is, but there's a chance that bubbles could manifest in a critical nerve structure - causing organ failure. Likewise, bubbles could manifest in an organ itself. Rare.
Perhaps your theoretical diver gets a bubble in the lower spinal cord - causing permanent erectile dysfunction and loss of bladder control. Death would be feasible by suicide.
There's secondary issues also. Bubble formation triggers an immune response. The body 'sees' the bubbles as an invader - white blood cells swamp the bubble. This can cause complications or secondary risks, such as clots. If the clots then become mobile move into/within the vascular system, that can be potentially very dangerous. This is one of the reasons why hyperbaric treatment may include immuno-suppressant drugs.
If you are interested in getting more detailed medical feedback on these issues, just let me know via PM - I'll move the whole thread into the 'Dive Medicine' forum where our resident Diving MDs will shed a lot more light on the specifics.
FWADIVER
Contributor
I think the main issue you aren't grasping is decompression is not a science, its voodoo. We have models that we think represent what the body undergoes, but there are a number of variables (some of which have been listed above including fatigue and hydration level) as well as likely a number of variables no one has discovered yet. Its not an exact science. If you push your luck you are rolling the dice with your health on the line, even staying within the 'accepted' limits has some risk.
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