Monthly Archives: March 2011

Question and Answer: What Happens When Someone Is Hanged?

Q: I’ve got a couple of questions about hanging. I have a 140-pound man of slight build who has been hanged. His neck is not broken and thus he is strangling. His hands are bound. How long might he survive before death? Would he lose consciousness well before or shortly before death? If he is taken down before death, we would certainly see abrasion of the neck. What else would we see? If unconscious, would he revive quickly? Could his injuries be life-threatening? (I’m thinking of throat swelling here) I am looking at pre-modern society here. No ER or modern medicine.

A: In hangings, death results from asphyxia, which is the reduction of oxygen to the brain. Asphyxia in hangings results from the compression of the airways and the carotid arteries (the arteries on either side of the neck that carry blood to the brain) by a noose or other ligature that is pulled tight by the body weight. Thus, the victim must be completely or partially suspended.


Though the airway can be compressed and breathing can be interrupted, the real cause of loss of consciousness and death in most hangings is compression of the carotid arteries, which blocks blood flow to the brain. Except for judicial (legally directed) hangings, fractures of the cervical vertebrae (spinal bones of the neck) are uncommon. The reason is that these fractures require that the body drop a sufficient distance to break them. How far is this? The answer depends upon several factors. Individuals who are obese, have small neck musculature, or who have arthritis of the cervical spine may suffer neck fractures quite easily. Just the opposite is true for muscular, thick-necked persons. In judicial hangings, these factors are considered in gauging the distance of the drop. Too little drop and the condemned person is strangled to death, too far and he could be decapitated.

The neck markings seen after hanging depends mainly on the nature of the noose used. Soft nooses such as sheets may leave little of no markings. Bruises and abrasions are not common with softer devices. In fact, if the victim uses a soft noose and if the body is discovered fairly quickly and cut down, the ME may not be able to find any marks at all. A rope or cord may leave a very deep, distinct furrow in the victim’s neck. The longer the body hangs, the deeper the furrow. Abrasions and contusions are more common with these types of nooses. Occasionally the furrow and any associated bruising may reveal the braid pattern of a rope or the link configuration of a chain.

In hangings, the furrow and the bruising will follow a typical course. The pattern is that of an inverted V. The furrow tends to be diagonal across the neck with its high end where the knot is located. The knot is usually to one side. This means that if the knot is to the victim’s left side, the furrow will be lower on the neck and much deeper on the right side and will angle upward toward the left ear. Near the knot, the furrow may shallow and disappear. This pattern is due to the body hanging by the “bottom” of the nose.

Okay, enough about hangings, let’s get to your situation. Since the asphyxia is due to compression of the arteries and not the prevention of breathing, loss of consciousness occurs very quickly, usually in a minute or less and maybe as short as 20 seconds. The brain needs a continuous supply of blood and when this is interrupted, consciousness is lost quickly. Death may take from 1 to 5 or 6 minutes.

If your victim is found within 2 to 3 minutes, he would be unconscious but could wake up fairly quickly—a couple of minutes. Or not. Some people die in a minute while others can take many minutes. Go with a couple of minutes but not longer and you’ll be OK. He would probably have the typical V-shaped bruises on his neck and a furrow that would resolve over a half hour or so.

He could return completely to normal or be left with brain damage or even remain in a coma for hours, days, weeks, months, years, or forever. It all depends upon how long the brain was deprived of blood and luck. This varies from person to person.


Clever Air-born Thief

Recently an unusual theft took place on an Air Antilles flight. Prior to take off $1.6 million in cash was stuffed into the cargo hold by a Brink’s security guard for transportation between the island of Guadeloupe and St. Maarten. However, $238,000 didn’t make it.

It seems that a very clever thief removed the panels that separated the toilet from the cargo area and made it off the plane and out of the airport with the cash. It also appears he might have had an accomplice who helped him fake an illness.

Here’s the story.

You can’t make this stuff up.


Posted by on March 27, 2011 in Interesting Cases, Theft


Guest Blogger: 10 Law & Order Plots That Were Shamelessly Ripped From the Headlines

This is from my friends at Criminal Justice Degrees Guide. It points out that we writers get our ideas everywhere, and often from real-life cases. And yes, we do so shamelessly. These are some of the stories used by the folks at Law & Order, one of the best and most successful TV franchises ever.

The take home message for crime writers here is that YES you SHOULD get your ideas from real life. It’s those stories that spark that all-important question: WHAT IF?

10 Law & Order Plots That Were Shamelessly Ripped From the Headlines

It’s hard not to blame the writers and producers of Law & Order for using the news as fuel for their stories. They’ve got a couple dozen episodes to film every season, and multiple franchises to keep up with. The flagship title ran from 1990-2010 and logged a ridiculous 456 episodes; after a while, it’s probably easier to just make up stuff based on the front page of CNN than it is to come up with something wholly original. But it’s not like the show only came to its “ripped from the headlines” format late in the game. Since the franchise’s inception, episodes have borrowed heavily from real life, sometimes to the point where disclaimers had to be made to keep the network out of hot water. Maybe we’re more aware now than before of the way the multiple series lift plots from real life, but the bottom line is that it’s hardly anything new. Here are some of the most shameless instances of “borrowing” in the franchise’s history.

“Haystack,” Law & Order: Special Victims Unit: Nancy Grace, the unhinged blonde lady from cable, has appeared on L&O several times in various incarnations, including the barely disguised “Faith Yancy” on Criminal Intent. (Presumably “Shmancy Mace” was too on-the-nose.) In the 2007 episode “Haystack” of SVU, a reporter accuses a woman of trying to kidnap and murder her own baby, a charge that leads to the woman committing suicide. This is basically a reworked version of the trouble Grace got into with Melinda Duckett, a 21-year-old mom who killed herself after appearing in an interview with Grace in which Grace badgered Duckett about the specifics of her past and whereabouts during the disappearance. Eventually, Duckett’s estate sued for wrongful death, and the case was settled out of court, with Grace establishing a trust whose funds will be given to Duckett’s son, if he’s found alive, or given to the National Center for Missing and Exploited Children.

“Subterranean Homeboy Blues,” Law & Order: “Subterranean Homeboy Blues” was the second episode ever aired of the original Law & Order, which means the show’s been borrowing from the news for more than two decades now. To be fair, though, this episode has a bit more originality and spark than some of the others. The installment deals with a woman who shoots and kills two men on the subway, and though the shooting is initially thought to be self-defense, it comes to light that it might be a revenge killing. The story is inspired by the actions of Bernhard Goetz, who killed four men on the New York subway in 1984 after saying they tried to rob him. He was branded the Subway Vigilante and came to represent a city fed up with crime. The fictional version, to its credit, changed the gender and played a bit looser with the story.

“Floater,” Law & Order: Airing in the fall of 2003, “Floater” was inspired by the trial of Gerald Garson, a New York Supreme Court Justice who was convicted of taking bribes to change the verdicts of divorce proceedings and who eventually served time for his crimes from 2007-2009. When the episode aired, Garson’s indictment was still fresh. The L&O version changed the judge to one who messes with murder cases — this is Law & Order, after all, so somebody’s gotta die — but ran with the angle of a crooked judge willing to break the law for the right price.

“Torch,” Law & Order: Special Victims Unit: The life and death of Cameron Todd Willingham have become a kind of touchstone for organizations dedicated to pursuing justice for those they believe to be wrongly accused, or by groups who want to abolish the death penalty. A mammoth 2009 story in The New Yorker pushed the case into the popular consciousness, at which point all bets were off for L&O. In April 2010, the episode “Torch” took the basics of the case — young girls die in a fire, their father is suspected of arson — and ran with it. The TV episode was (pardon the pun) a bit overcooked, but it also worked out more happily than the real case. On the show, the father was found innocent thanks to holes in the theories of the fire scientists. Willingham wasn’t so lucky.

“Innocence,” Law & Order: The Innocence Project is one of several advocacy groups devoted to securing new trials for those who might be wrongly imprisoned. In 2010, the episode “Innoncence” revolved around the fictional Innocence Collective and their similar cause. The episode was based in part on allegations of impropriety by students working with the Medill Innocence Project: a pair of witnesses claimed to have been coerced into giving certain testimony in a murder case. The TV version of events turns the group (or at least certain members of it) into committed bad guys, blinded by a cause, which can’t have felt good to the actual Innoncence Project. At least it’s just TV.

“Out of the Half-Light,” Law & Order: Airing in December 1990, “Out of the Half-Light” was based mostly on the Tawana Bradley case of 1987. Bradley, a black teenager, accused six white men (including some cops) of raping her in the woods. Public sentiment was with her until a lack of evidence did her in. A grand jury eventually decided that she hadn’t been a victim of such assault. The TV adaptation played to the racial angle that had so galvanized the public in the original case, though obviously, there’s only so much nuance you can achieve in 44 mninutes. The episode helped cement the series’ habit of looking to the headlines for story ideas.

“Bombshell,” Law & Order: Criminal Intent: The Criminal Intent series is all about “major cases,” which is the simplest way to say that these episodes are almost always going to be cobbled together from the front page of The New York Post. The 2007 episode “Bombshell” is no exception. See if this sounds familiar: a former stripper and model marries a famous billionaire, has a son, and sees that son die as an adult of an overdose. If you said “That’s the short version of Anna Nicole Smith’s Wikipedia page,” give yourself a prize. This episode isn’t the only one in the L&O-verse to use Smith’s sad life as fuel for a story, though it is the one that hews closest (for whatever that’s worth) to the basic facts. In the episode, as in real life, the woman soon dies, leaving behind a baby.

“Fed,” Law & Order: Airing in the 20th and final season of the original Law & Order, the 2009 episode “Fed” was built on the death of Bill Sparkman, a Census Bureau representative who was killed in the fall of that year. (The show works fast.) Sparkman’s body was found tied to a tree, with the word “fed” written on his chest. It looked like a homicide, but investigators later determined it was a suicide staged to look like a murder. Now, a twist like that would be easy and fine to use in a TV show, but L&O throws in everything else, too. The TV episode deals with an election campaign volunteer whose body is also found with “fed” written on the chest, which leads to weird cover-ups that rope in the brain-dead hijinks of fake pimp James O’Keefe and the purported ACORN scandal. In other words, way too much for one hour of TV. It’s a prime example of how the series often feels it has to rip from seven headlines at once.

“Weeping Willow,” Law & Order: Criminal Intent: Law & Order often uses adorably awful mirror versions of real-life things in its stories. This episode features the not-at-all-awkwardly-titled YouLenz, which is as close as the producers could get to YouTube without paying for it. The hour revolves around a female video blogger with the handle “WeepingWillow17,” which is just a lazy half-step from “Lonelygirl15.” It’s not that they shouldn’t use the Lonelygirl thing for plot fodder; it’s that they don’t even change the names that much. The Lonelygirl15 affair was a series of viral videos on YouTube meant to drum up support for an eventual feature, but the Law & Order version is much more sordid, involving a staged kidnapping and a heartless girl (Michelle Trachtenberg) looking for fame at any cost. It’s intended to be a commentary on modern celebrity culture, but it’s not much more nuanced than “Computers are bad.”

“Indifference,” Law & Order: Trivia: this is the only episode of Law & Order in which the narrator actually told people that the story resembled a real-life case. It’s not uncommon for the series to have title-card disclaimers (“All similarities are purely coincidental,” etc.), but for the narrator to actually speak the warning aloud is a pretty big deal, and a sign of just how much the episode owed to the real world. The episode was based on the case of Joel Steinberg, a New York attorney who was supposed to find an adoptive family for a young girl but instead took her and raised her as his own with his live-in girlfriend, Hedda Nussbaum. On the show, the detectives discover that a psychiatrist and his wife, both addicted to drugs, are abusing their child, and the various lies they’ve told to keep her come to light after she dies. It’s interesting that 20 years ago, an episode that owed such a debt to real-life crime paid tribute with a vocal disclaimer, while today it’s commonplace for Law & Order to mash up several news stories and not even pretend to care that they’re unoriginal. If only we’d know how good we had it.



Question and Answer: Could Death From Bleeding Be Delayed For Several Days After a Frontier Wagon Wheel Accident?

This is a question that appeared in my 2003 book Murder and Mayhem.

Q: My story takes place in a wagon train in the late 1800’s. My character is dragged by a horse while crossing a river. He hits rocks and is bounced off the back wheel of a wagon. Of course the horse’s hooves do damage as well. Three days later he dies from massive bleeding from his internal injuries. This three day delay followed by the sudden loss of blood is important to the story’s timing, but is it realistic?


A: The answer to your question is yes.

This type of accident could, as you can imagine, result in all types of injuries. Broken bones, skull fractures, neck fractures, cracked ribs, punctured lungs, and intra-abdominal injuries (injuries inside the abdominal cavity). This last type of injury might serve you well.

A ruptured spleen or lacerated liver or fractured kidney would bleed into the abdominal cavity. Death could be quick or take days if the bleed was slow. There would be great pain, especially with movement or breathing, and the abdomen would swell. Also a bluish, bruise like discoloration could appear around the umbilicus (belly button) and along the flanks. This usually takes 24 to 48 hours or more to appear. This occurs as the blood seeps between the “fascial planes.” The fascia are the tough white tissues that separate muscles from one another. The blood seeps along these divisions and reaches the deeper layers of the skin causing the discoloration. But, these injuries wouldn’t lead to external bleeding since the blood has no exit from the abdominal cavity.

However, if the injury was to the bowel, then external bleeding could occur. For blood to pass from the bowel, the bleeding would have to be within the bowel itself and not just in the abdomen somewhere. If the bowel were ruptured or torn so that bleeding occurred within the bowel, the blood would flow out rectally. But, blood in the bowel acts like a laxative so the bleeding would likely occur almost immediately and continue off and on until death, which in this situation would be minutes to hours to a day, two at the most. It would be less realistic for the bleeding to wait three days before appearing in this case. With one exception.

The bowel could bruised and not be ruptured or torn, and a hematoma (blood mass or clot) could form in the bowel wall. As the hematoma expanded it could compromise the blood supply to that section of the bowel. Over a day or two the bowel segment might die. We call this an “ischemic bowel.” Ischemia is a term that means interruption of blood flow to an organ. If the bowel segment dies, bleeding would follow. This could allow a 3 day delay in the appearance of blood.

In your scenario, the injuries would likely be multiple and so abdominal swelling, the discolorations I described, great pain, fevers, chills, even delirium toward the end, and finally bleeding could all occur. Not a pleasant way to die, but I would imagine this happened not infrequently in frontier days.

The victim would be placed in the bed of one of the wagons and comforted as best they could. He might be sponged with water to ease his fevers, offered water or soup, which he would likely vomit, and prayers would be said. They could have tincture of opium (a liquid) available and give him some. This would lessen the pain since it is a narcotic and would also slow the motility (movement) of the bowel and thus lessen the pain and maybe the bleeding.

Of course, during the time period of your story, your characters wouldn’t know any of the internal workings of the injury as I have described. They would only know that he was severely injured and in danger of dying. Some members of the wagon train might have seen similar injuries in the past and might know just how serious the victim’s condition is, but they wouldn’t understand the physiology behind it. They might even believe that after he survived the first two days that he was going to live and then be surprised when he eventually bleed to death. Or they might understand that the bouncing of the wagon over the rough terrain was not only painful but also dangerous for someone in his condition. The train might be halted for the three days he lived or several wagons might stay behind to tend to him while the rest of the column moved on.

The entire Table of Contents of Murder and Mayhem can be seen HERE.


The Andromeda Strain Lives

Remember the late Michael Crichton’s landmark science fiction novel and pretty cool movie The Andromeda Strain? The story revolved around an alien strain of biological material that hitchhiked its way to Earth on a retrieved military satellite. Pure science fiction. Great science fiction. Totally speculative.


But now it just might have happened. It seems that astrobiologist Dr. Richard B. Hoover from NASA’s Marshall Space Flight Center has uncovered an alien, space-traveling bacterium. This one grabbed a ride on a meteorite. Scanning electron microscopy has revealed the fossil of a large bacterium, similar to one found on Earth, hidden inside the chunk of space rock.

Is this evidence of life in space? Is it conceivable that some space traveling organism could fall to earth and wipe us all out? Who knows. Time will tell.

As it says on the cover of The Hitchhiker’s Guide to the Galaxy: “DON’T PANIC.”


Dr. Hoover has invited 100 experts to review and analyze his work so hopefully we will know more about this creature, bacterium, apocalyptic organism, or what ever it is as further study is done.

But it should add speculative fuel to those of you who write in the sci-fi genre.


Question and Answer: Can Carbon Monoxide Cartridges be Used as a Method of Murder?

Q: My victim is in a locked room with one small window in an abandoned warehouse and is being slowly killed by carbon monoxide fumes from little cartridges that are timed to activate at certain intervals. There is also a booby trapped bomb in a briefcase in the same room, which will be detonated when the levels of carbon monoxide are high enough. How long would it take the victim to fall unconscious? Is it possible to ignite a bombs fuse with this gas? If it is possible, and the victim is rescued before the bomb detonates would they be able to recover completely from carbon monoxide poisoning and how long does recovery take?

A: First of all, carbon monoxide will not explode nor does it readily burn so using it as a fuse or as an explosive material isn’t a possibility. You could have a carbon monoxide detector on the bomb that would ignite when a certain level was reached so in this regard it could be viewed as a fuse of sorts.

Carbon Monoxide (CO) is stealthy, treacherous, and deadly. It’s also common. You’ve seen it in the papers or on the news. A family is found dead and the cause is a faulty heater or fireplace. A suicide victim is found in his garage with the car engine running. Campers are found dead in a tent, a kerosene lantern burning in one corner. Each of these is due to carbon monoxide.

CO is a tasteless, odorless, colorless gas that is completely undetectable by humans. It results from the incomplete combustion of carbon-containing fuels—paper, wood, gasoline, and many other combustible products. Faulty stoves, heaters, and fireplaces as well as the exhaust from a car engine can fill the air with CO. Carbon monoxide poisoning is a more common cause of death in fires than is the fire itself. In your scenario, you supply the CO via cartridges so none of this is needed in your story, but this may be part of the investigation as to why the victim had CO toxicity—-if the cartridges aren’t found, etc.

Carbon Monoxide’s treachery lies in its great affinity for hemoglobin, the oxygen (O2) carrying molecule within our red blood cells (RBCs). When inhaled, CO binds to hemoglobin producing carboxyhemoglobin. It does so 300 times more readily than does oxygen and thus displaces oxygen. In other words, if the hemoglobin is presented with both oxygen and carbon monoxide it is 300 times more likely to combine with the CO. The result is that the blood that leaves the lungs and heads toward the body is rich in CO (carboxyhemoglobin) and poor in 02 (oxyhemaglobin).

This strong affinity of hemoglobin for CO means that very high blood levels can occur by breathing air that contains only small amounts of CO. For example, breathing air that contains a carbon monoxide level as low as 0.2 % may lead to blood CO saturations greater than 60% after only 30 to 45 minutes. So, a faulty heater or smoldering fire that produces only a small amount of CO becomes increasingly deadly with each passing minute.

This powerful attraction for hemoglobin explains how certain individuals succumb to CO poisoning in open areas. Most people believe that CO is only toxic if it is in an enclosed area, but this is simply not true. There have been cases of individuals dying while working on their car in an open area, such as a driveway. Typically the victim is found lying near the car’s exhaust. Similarly, the newly recognized problem of CO poisoning in swimmers and water skiers, who loiter near a dive platform on the back of a powerboat whose engine is at idle, is another example of this affinity.

The degree of exposure to CO is typically measured by determining the percent of the hemoglobin that is carboxyhemoglobin. The signs and symptoms of CO toxicity correlate with these levels. The normal level is 1 to 3%, but may be as high as 7 to 10% in smokers. At levels of 10 to 20%, headache and a poor ability to concentrate on complex tasks occur. Between 30 and 40%, headaches become severe and throbbing and nausea, vomiting, faintness, and lethargy appear. Pulse and breathing rates will increase noticeably. Between 40 and 60% the victim will become confused, disoriented, weak, and will display extremely poor coordination. Above 60% coma and death are likely. These are general ranges, but the actual effect of rising CO levels varies from person to person.

In the elderly and those with heart or lung disease, levels as low as 20 percent may be lethal. Victims of car exhaust suicide or those that die from fire in an enclosed room may reach 90 percent.

Carboxyhemoglobin is bright red in color and imparts this hue to the blood. When the ME performs an autopsy and sees bright cherry-red blood, he will suspect CO poisoning as the cause of death. This finding does not absolutely specific since cyanide inhalation or ingestion can also result in bright cherry red blood and tissues. Also, individuals dying from cold exposure or corpses exposed to very low temperatures may show bright red blood. Livor mortis in these situations may also be red or pink in color.

At autopsy, the internal organs in victims of CO intoxication are also bright red. Interestingly, this color does not fade with embalming or when samples taken by the ME are fixed in formaldehyde as part of the preparation of microscopic slides.

Individuals who survive CO intoxication may have serious long-term health problems. The brain is particularly vulnerable since it is extremely sensitive to oxygen lack. Symptoms and signs of brain injury can begin immediately or be delayed for several days or weeks. The most common after effects include chronic headaches, memory loss, blindness, confusion, disorientation, poor coordination, and hallucinations. The ME may be asked to evaluate a living victim in this situation if the exposure was due to a criminal act or if a civil lawsuit is involved.

Your victim would become sleepy, confused, disoriented, clumsy, and develop headaches as the level of CO in his body rose. He would finally lapse into a coma and would die if not rescued in time. Treatment is simply to remove him from the area and given him oxygen by way of a face mask and oxygen tank. If he is to be OK it should only take a few minutes to an hour to recover. He might then be normal or have any of the above long-term problems.


Posted by on March 13, 2011 in Asphyxia, Medical Issues, Q&A


Helpful Hint of the Day: Don’t Piss Where You Rob

Here is your helpful hint for the day–don’t piss where you rob. It seems that a twenty-seven-year-old Swedish man didn’t get the message. He and his buddy broke into a bank and began emptying safe deposit boxes. They had a couple of partners outside with cell phones keeping tabs on the movements of the security guards. Sounds like a good plan. Unfortunately nature called and one of the thieves had to relieve himself and he did so in a plastic bag which he unwisely left behind.

Urine is simply a liquid that contains a lot of waste products, electrolytes, and other things of the body no longer needs. It doesn’t contain DNA. However, the cells that line the urinary tract do and these are picked up by the urine as it moves from the kidneys to the environment. The police were able to extract DNA from the urine sample the thief so helpfully left behind and were able to identify him in that manner.

Some stories just make you feel all warm and tingly. Excuse me, I’ve got to go hit the head.


Posted by on March 10, 2011 in DNA, Interesting Cases, Theft


Sweat Lodge Death Trial Begins

“You will feel as if you are going to die. I guarantee that.”

“You will have to get to a point where you surrender, where it’s OK to die.”

In an earlier post I talked about the hyperthermic deaths that occurred during the self-discovery sessions led by self-help guru James Ray. His sweat lodge ordeal ended in the death of three and hospital visits by nearly two dozen others. It appears that his trial is about to begin in Arizona.

I bet he now regrets the above words. Bet he’s sweating as if he were in his own sweat lodge.

The defense? Well, the participants were adults. They signed wavers. I wonder if those wavers mentioned the temperature and lack of ventilation and jam-packed conditions inside the lodge? Or that there would be no on site medical facility or personnel? Or that their 36 hour fast ended by a single meal just might leave the participants a bit dehydrated even before they entered the jerky factory. Brains, hearts, and kidneys don’t tolerate such conditions well.

Common sense, or as we say in the South “walking around sense,” seems to have flown the coop in this deal.

This one will be interesting to watch.


Games Children Play: The Choking Game, The Pass Out Game

Remember all the young and stupid things you did when you were young and stupid? Jumping off the garage with a pillowcase parachute? Swinging off a tree limb into the creek or pond without first testing the depth of the water? Building a ramp to jump over on your bicycle? Taking a ride while clinging to a car front fender? We all did these things yet somehow survived. Unfortunately young Brandon Stine didn’t.

There seems to be a game going around among children Brandon’s age, which was 11 at the time of his death. It goes by many names: the Choking Game, the Fainting Game, the Pass Out Game, Tap Out, Hangman, Elevator, and a few others. The goal is to lose consciousness. I remember in grammar school a similar game came around. The person would take 20 deep breaths and blow on their thumb and immediately become dizzy and lose consciousness. I never played this game but I saw it on several occasions. Somehow losing consciousness wasn’t very appealing to me. And of course now that I know the physiology behind it, it is not only unappealing it is frightening.

The current games are played two ways. The first is easy to understand and the second requires a little more complex physiology.

One form is simply to choke the victim until he loses consciousness. This is basically the choke hold police sometimes employ to control combative suspects. The purpose is to block blood flow to the brain by compressing the carotid arteries. This results in low oxygen levels in the brain, which in turn leads to loss of consciousness. It can also lead to death.

The second form results from self-induced hypocapnia. Hypocapnia is simply a big word for low carbon dioxide (CO2) levels in the blood.

The human body guards a handful of things very jealously. Some of these are the oxygen, CO2, and pH of the blood. The pH is a measure of the balance between acid and base (alkalinity) in the blood.

When oxygen levels are low, the brain sends out signals that increase the rate and depth of breathing as well as the heart rate and blood pressure. This brings more oxygen into the lungs and increases its transportation by way of the cardiovascular system to the body. When the level of oxygen in the blood is very high the exact opposite happens in that breathing will slow since there is no physiologic need to move more air.

Carbon dioxide works the same way, only in reverse. If the carbon dioxide levels are high, breathing will increase to “blow off” this extra CO2, which is an acid. Since CO2 is removed from the body through the lungs any increase in breathing rate and depth will remove more CO2 from the body and the acid-base balance (the pH) will be restored. If the CO2 is very low, this drive to breathe is suppressed so that more CO2 will accumulate within the blood and again restore the pH balance.

High CO2 levels elevate the amount of acid in the blood and this is reflected in a falling pH level. The lower the pH the more acidic the body is. A low pH adds to the drive to breathe more rapidly so that the CO2 level will drop and the excess acid is removed in this way. When the CO2 level drops, the pH rises and the drive to breathe is suppressed.

This is a thumbnail and does not take into consideration the many other derangements within the body that can alter the pH level.

In summary, a low oxygen level, a high CO2 level, and a low pH (excess acid in the system) tend to increase breathing so that more oxygen is supplied and more CO2 is removed from the body. When the oxygen level is high, the CO2 level is low, and the pH is elevated (excess alkalinity in the system) the driving force to breathe is suppressed.

When someone purposely hyperventilates by breathing rapidly and deeply for a minute or so they are increasing their oxygen and pH levels while lowering their CO2 levels. This in turn suppresses the need to breathe. This can lead to a period of slow or absent respiration, which tends to continue slightly longer than is needed. This overshoot is part of virtually all biological feedback systems. This can result in a rapid drop in blood oxygen levels to the point that the victim loses consciousness.

This drop in blood oxygen level is more dramatic and more rapid than is the restoration of normal CO2 levels that would accompany a cessation of breathing. This means that by the time the CO2 levels reach a point where they again drive respirations, the oxygen level has fallen very far. This is what leads to loss of consciousness and death. Or perhaps survival with permanent brain damage.

An identical situation arises when someone attempts an underwater swim across a pool. Or a free diver attempts to go to very great depths on a single breath. In each of these situations the person hyperventilates before taking the plunge and in so doing creates a situation where they could lose consciousness and drown during the swim or the descent.

If you, or anyone you know, has children who are playing this game, it’s time to sit down and have a chat. This is basically Russian Roulette where the bullets are the oxygen and carbon dioxide levels in the blood.

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