What is Brain Death?

Death occurs when a living organism (a person for example) can no longer independently maintain the essential body functions (breathing, a beating heart, etc.) that are necessary to keep the person as a whole alive. As a general rule, death occurs when the body can no longer supply its vital organs, like the heart, the lungs, and the kidneys, with enough oxygen to keep these organs going. This lack of oxygen, termed hypoxia in medicalese, can occur for multiple, multiple different reasons. For example, a person with severe lung disease might die from hypoxia because they can’t effectively breath whereas a person who has suffered a massive heart attack is at risk of dying because their heart can’t circulate oxygen (from the lungs) through the blood to reach the other vital organs –different mechanisms causing organ hypoxia, but with the same end result. 

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An Egyptian mummy. If only it were always so obvious when people are dead my job would be much easier…

The reason that oxygen is important to the body is because it is used to “burn” the biological fuels that we all obtain by eating to produce the energy that body tissues need to stay alive — no energy, no life. Different organs die at different rates when they don’t get enough oxygen. For instance, the brain begins to die after about 4 minutes of oxygen deprivation whereas skeletal muscle (your biceps muscles for example) can last for up to 4 hours without an adequate oxygen supply — a really big difference!

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An image of human cells growing in a laboratory. These are HeLa cells, cells which were taken from Henrietta Lacks’ fatal tumor before her death in 1951 (without her consent) and have since become the standard human laboratory cell for study. No one objects to disposing of old HeLa cells, but the individual cells are very much alive, another excellent demonstration of why the distinction between life and death isn’t quite as obvious as most would think. 

Okay, hang in there because I’m going somewhere important with all of this. The concept of brain death didn’t exist until the advent of mechanical ventilation, aka: life support. Since the brain controls breathing, the blood pressure, and (indirectly) the heart, before the invention of life support a person with a nonfunctioning brain rapidly progressed to a state in which none of their other organs (lungs, heart, etc.) were working either — they were either obviously dead or they weren’t. Mechanical ventilation and other advanced intensive care techniques changed all of this by enabling physicians to artificially keep a persons heart and lungs working even if the brain was damaged beyond repair. This is because the brain is the first tissue to die when a person’s body has an inadequate supply of oxygen and sometimes physicians are able to treat people only after their brain has been irreparably damaged, but before their heart, lungs, kidneys, and other vital organs have begun the irreversible dying process. This scenario is really important for several reasons and more common than you might think.

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A mechanically intubated American serviceman injured overseas and being prepared for brain surgery. The tube coming out of his mouth continues down his trachea (the airway) and is attached at the other end to a mechanical ventilator. The black device on his head is used during neurosurgery to precisely localize portions of the brain in the operating room.

Because keeping a person’s body breathing on a ventilator when their brain is irreversibly destroyed makes absolutely no sense, physicians began contemplating the need for a diagnosis (that did not exist at the time) to convey to patient’s families the irreversible nature of the damage to their loved one so that they wouldn’t suffer from delusions of false hope and so that limited Intensive Care Unit beds wouldn’t be taken up by patients with no chance of recovery (and therefore possibly denied to other patients who might recover due to lack of beds). The answer to this conundrum was the development of the concept of “brain death” by the medical community, a concept that met great resistance from some quarters and which was highly controversial outside of the world of medicine until at least the mid-1970s, nearly three decades after mechanical ventilation became a common place treatment in intensive care units.

In 1954 the world’s first successful internal organ transplantation occurred (it was a kidney transplant that was performed in The United Kingdom) and over the next three decades organ transplantation became widespread, saving thousands upon thousands of lives that otherwise would have ended prematurely. Because brain dead patient’s often have little wrong with their other vital organs, at least in the first few hours-to-days, people who have suffered brain death are the source a very large proportion of donor organs. This is because many cases of brain death are caused by head trauma and many head trauma victims are young people with otherwise extremely healthy organs (you wouldn’t want a kidney transplant from a dead elderly person whose kidney’s had been damaged over the years from diabetes and high blood pressure, right!). The fact that brain dead patient’s have no chance of recovery, coupled with the fact that their internal organs can potentially save the lives of many others, led the Federal Government in The United States to finally get off its butt and propose national standards for the determination of brain death, standards which were approved in 1980 and soon thereafter adopted by an overwhelming majority of the 50 States.

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The fluid-filled abdomen of a man with end-stage cirrhosis. A liver transplant would likely save his life. Not all cirrhosis is caused by alcohol, by the way. Genetic diseases, drug reactions, and autoimmune diseases can all destroy the liver as well.

Before we delve deeper, let’s briefly look at the 5 categories of Altered Levels of Consciousness: Confusion, Delirium, Obtundation, Stupor, and Coma. A confused person is mildly disoriented while a delirious person is completely disoriented and also may have both hallucinations (e.g. hearing voices or seeing things that do not exists) and delusions (e.g. thinking that the nursing staff is trying to kill them). An obtunded person is sleeping but you can wake them, at least for a little whle, by talking to them or with other gentle stimuli, for instance by nudging their shoulder. Patients in a stupor can only be aroused by causing pain and a very common way to do this in the hospital is to forcefully rub the patient’s breastbone with your knuckles or to press down hard onto one of their fingernails with pen or with the metal shaft of a reflex hammer. A person who is absolutely unable to be awakened is in a coma.

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An obtunded cat, greatly in need of a referral to Alcoholics Anonymous. Let’s all pray for him tonight…

Okay, returning to brain death. All brain dead people are in a coma but not all people in a coma are brain dead. Coma’s have multiple causes and some are reversible while others are not. The first thing that a physician does when they evaluate a person who is potentially brain dead is to look for a known cause (e.g. a motorcycle/”donor cycle” accident in a person who wasn’t wearing a helmet). The next step is to rule out any potentially reversible, i.e. “fixable,” conditions that might be contributing to the patient being in a coma, especially drugs/alcohol, electrolyte abnormalities, and hypothermia — “you’re not dead until you’re warm and dead” — as the ER maxim goes.

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As with all maxims, there are probably some reasonable exceptions to “you’re not dead until you’re warm and dead.” This is a frozen juvenile wholly mammoth fossil.

In order to be declared brain dead in The United States a person must undergo a thorough examination by at least two physicians. Both of these physicians perform an extensive neurological examination. Brain dead patient’s are unresponsive to painful or noxious stimuli above the neck, have unresponsive dilation of the pupils, no gag reflex, and do not breath spontaneously (as determined by a specialized “apnea test”). If all of these findings are consistent with the diagnosis of brain death on both physicians’ separate physical examinations then the patient can be declared dead.

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A spinal reflex — no brain required.

Interestingly, brain dead patient’s often do have a response to painful stimuli below the neck and they can even move in response to it (e.g. moving an arm when it is stimulated). This is because the reflexes below the neck are controlled via the spinal cord and sometimes the spinal cord takes longer to die than the brain. Another interesting category of patients is people who have obviously suffered a brain injury that is so severe that they are in an irreversible, permanent coma but who don’t meet the full criteria for brain death. These people are in a “vegetative state.” Vegetative states have a poor prognosis and people who have been in a vegetative state for greater then one year (like in the Terri Schiavo case) essentially have a zero percent chance of recovery. 

The first take home message is to please treat your brain gently and wear a helmet, seatbelt, and other commonsense safety equipment when engaging in activities that can result in head injury such as skateboarding, riding a bicycle, and driving an automobile. The second take home message is to please consider signing an advance directive with your family and physician so that your wishes are known as to the extent of treatment that you would desire if you were to suffer a severe brain injury (would you want to be an organ donor and potentially save someone’s life?). We all live in a dangerous world full of automobiles driven by distracted drivers — think ahead and spare your family the agony of having to make difficult decisions for you without knowing what your wishes would have been.

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Three people on a motorcycle without helmets, a fantastic example of a really bad idea!

Dr. Leonardo Noto

Physician and Author of Medical School 101, Intrusive Memory, The Life of a Colonial Fugitive, and The Cannabinoid Hypothesis. Amazon Link to Doc’s Writing:  http://www.amazon.com/Leonardo-Noto/e/B00ATVOMCW/ref=ntt_dp_epwbk_0

NOTE: The Life of a Colonial Fugitive — my dark historical thriller — is free for your ereader at http://www.smashwords.com/books/view/215272. Thanks for reading!

Author Bio: Dr. Leonardo Noto is the nom de plume of a former airborne battalion surgeon who is now in civilian practice. Dr. Noto is the author of four books and he also writes for a medical education corporation that assists medical students, interns, and residents as they prepare for the medical board examinations. Dr. Noto is the proud father of an extremely spoiled 16-month-old American Bulldog who enjoys slobbering everywhere and tearing up things that he is not supposed to! Dr. Noto is an amateur practitioner of muay Thai and Brazilian jiu jitsu and he recently began learning to play the guitar (but he is currently a quite terrible musician, as his neighbors will readily attest).

Remember to discuss all health concerns with your personal physician (I don’t count!) before making any medical decisions. www.leonardonoto.com is intended to present general medical information for entertainment purposes and not as specific guide to any medical treatment. The author has made every effort to present accurate information; however, due to the ever-changing nature of medicine and the intrinsic caveats that are inherent in any particular case, no medical decisions should ever be made based on information gleaned from the internet (duh!). The internet and self-education are great, but they don’t replace your Doc!

The opinions voiced on this medical blog are solely the author’s own and they do not reflect the opinions or values of Dr. Noto’s employers, past or present. Dr. Noto’s medical blogs should never be used as supporting evidence for legal testimony — this is of course obvious to anyone who isn’t a complete moron, but some people are rather stupid.

References

Reynolds, NC. Special Issues in Medicolegal Neurology. In emedicine. http://emedicine.medscape.com. Sept. 16, 2009.

Young, BG. Diagnosis of Brain Death. In UpToDate. http://www.uptodate.com. May 17, 2012.

Determination of Death Act Summary. Uniform Law Commission. http://www.uniformlaws.org. 2013.

Loss of Consciousness. In PDR Health. http://www.pdrhealth.com/diseases/loss-of-consciousness.

First Successful Kidney Transplant Performed in 1954. In: A Science Odyssey — People and Discoveries. http://www.pbs.org.

The Multi-Society Task Force on PVS. Medical Aspects of the Persistent Vegetative State.  N Engl J Med 1994;  330:1572-1579.

Egyptian Mummy: http://commons.wikimedia.org/wiki/File:Mummy-UpperClassEgyptianMale-SaitePeriod_RosicrucianMuseum.png

HeLa (Henrietta Lacks) Cells: http://en.wikipedia.org/wiki/File:HeLa_Cells_Image_3709-PH.jpg

Ventilated Head Trauma Patient: http://en.wikipedia.org/wiki/File:US_Navy_040723-N-8977L-008_Navy_Hospital_Corpsmen_and_Medical_Officers_assess_the_treatment_and_prognosis_of_a_patient_with_a_gunshot_wound.jpg

Hepatic Cirrhosis: http://en.wikipedia.org/wiki/File:Hepaticfailure.jpg

Burns, M. Cat with a Drinking Problem: http://www.flickr.com/photos/mike-burns/35538355/sizes/m/in/photostream/

Frozen Wholly Mammoth: http://en.wikipedia.org/wiki/File:Mamut_enano-Beringia_rusa-NOAA.jpg

Patellar Reflex: http://www.google.com/imgres?imgurl=&imgrefurl=http%3A%2F%2Fmeded.ucsd.edu%2Fclinicalmed%2Fneuro3.htm&h=0&w=0&sz=1&tbnid=TbeJEv9WUMdqNM&tbnh=259&tbnw=194&zoom=1&docid=pBB_SrdVm0_2QM&hl=en&ei=Rhs1Usm1GZPEqQGP4oH4CA&ved=0CAEQsCU

Donor Cycle: http://en.wikipedia.org/wiki/File:Family_transport_in_Tehran.jpg

Biological Weapons of Mass Destruction

Unless you’re living in a cave, or perhaps a man-cave with your eyes glued to ESPN College Football, then you undoubtedly know that The United States is currently contemplating an attack against Syria in retaliation for the Assad regime’s use of chemical weapons against civilians. Since I already authored a recent article on chemical weapons of mass destruction, today I would like to discuss biological weapons of mass destruction, weapons which are even scarier than sarin or mustard gas. As always, the best way to understand complicated issues today, including the use of weapons of mass destruction, is to examine (briefly in our case) the history of these weapons.

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This is a photograph from WWI of blinded soldiers being led in a line away from a chemical weapons attack, the winds mercifully having changed directions and now blowing the deadly gas away from these victims. Many biological agents can be dispersed in a similar fashion, although the amounts needed to cause massive damage would be much, much smaller.

Biological weapons primarily consist of three categories of substances: bacteria, bacterial toxins, and viruses. Historically, the biggest killer on the battlefield wasn’t swords, bows, guns, or artillery — it was germs, especially typhus, which is caused by a bacteria that is carried by the human body louse (a rare parasite today thanks to modern hygiene, but very common up until at least World War I). The intentional use of biological weapons dates back to at least feudal times, when enemy armies would catapult the victims of plague (a bacteria), smallpox (a virus), and other nastiness over the walls of enemy cities. During World War II the Japanese extensively used both chemical and biological weapons against the Chinese, including the dropping of “plague bombs” from their aircraft into Chinese cities — essentially cannisters that were full of fleas carrying the bacteria Yersina pestis that causes bubonic plague (aka: “The Black Death”).

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This is Shiro Ishii, the microbiologist and general who led Japan’s infamous Unit 731 during WWII. Unit 731 was responsible for Japan’s biological weapons program and also participated in dissections of living human beings and other horrific medical experiments that were performed on living, unanesthetized humans. Dr. Shiro Ishii was not punished for his crimes.

As terrible as these examples are, the greatest biological attacks in history have actually been unintentional. Nonetheless, these unintended “attacks” show us how potentially devasting an intentional biological attack might be — a scary prospect given that manufacturing biological weapons is actually pretty easy to do (anthrax probably lives in soil your backyard!!!). While “The Black Death” of Europe is probably the most infamous example of a massive pandemic decimating a population, having killed at least one person in three in 14th century Europe due to the inadvertent transmission of Yersina pestis infected rats/fleas aboard trading ships, the most poignant example of (mostly) inadvertent biological catastrophy actually occurred in the Americas and it is largely responsible for the cultural makeup of North and South America today.

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Florid smallpox afflicting a child.

Unlike Europeans, Africans, and Asians, who had lived in contact with one another and with one another farm animals (the initial source of many human pathogens), Native Americans had no innate resistance to smallpox, measles, and a host of other diseases that Europeans brought with them after Columbus’ monumental voyage of 1492. Although hard numbers are difficult to come by, it is likely that in many areas up to 90% of the native population died from these diseases in a very short period of time, ultimately making their conquest by Europeans much easier than it otherwise would have been. A particularly good example is The Pilgrims, who landed in Cape Cod to find fertile lands that were devoid of inhabitants and that just so happened to also be filled with lots of recently emptied villages. This was not a coincidence! European traders had visited the area shortly before The Pilgrims arrival and the bustling native population was ravaged by the diseases that they brought with them. Had the Pilgrims landed at any other time they would have certainly been driven off. However, the remaining Native Americans decided to put up with The Pilgrims because they thought that they might be useful allies against their adversary tribes, who had not (yet) been affected by European diseases — it seemed like a good idea at the time! By the way, if you want to read more on the topic of the European/Native American first encounters I highly recommend these two books, both of which I strongly based this paragraph upon — Mann, C.C. 1491: New Revelations of the Americas Before Columbus by Charles Mann and Guns, Germs, and Steel by Jared Diamond.

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The evolution of the wound/scar that forms after smallpox vaccination.

The mid-20th century marked a period of bustling research into weapons of mass destruction and biological weapons of mass destruction were no exception. At one point both The United States and The Soviet Union measured their biological weapons stockpiles in tons. The average car weighs 1-2 tons — a useful “yardstick” to wrap your head around how much of this stuff their was (is?) in the world not very long ago. The good news is that both The United States and the former Soviet Union, aka: Russia, began officially destroying their stockpiles of biological weapons during the 1990s. The only countries today with likely stockpiles of biological weapons that also publically have stated that they would consider using them in war are North Korea and Syria, the bad news being (for American readers) that we have officially been at war with North Korea since the 1950s and we are probably about to march off for a little adventure in Syria due to the regime’s recent blatant use of chemical weapons (probably sarin gas) against civilians. Before we look at specific types of biological weapons, here’s a list of countries that have or had biological weapons at one point in the not too distant past (courtesy of The Arms Control Association): Russia, The United States, China, Syria, North Korea, and Libya. Other countries which may possess or may have possessed biological weapons are: Egypt, India, Iran, and Israel.

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Bashar Al-Assad, the dictator of Syria, who is also an ophthalmologist by training (a medical doctor who specializes in eye surgery). The deathtoll is much higher now, by the way.

Types of Biological Weapons:

1. Smallpox: The only disease ever eradicated by the actions of mankind, smallpox was declared extinct by The World Health Organization in 1980 after a decades-long global vaccination effort. Smallpox was capable of killing in excess of 1/3 of its victims and of incapacitating most of the rest for periods of weeks to months. Those who recovered were often maimed for life with deep pockmarks over their faces and bodies Smallpox vaccination with a related bovine virus, cowpox, actually began long before Edward Jenner popularized the technique in 1796; indeed, after witnessing the effects of smallpox firsthand (he bore facial scars for the rest of his life), General George Washington began the practice of compulsory smallpox vaccination in the American (Continental) Army in 1777 that continues to this day. While an effective vaccine does exist for smallpox, there is no effective cure once you have the disease. Smallpox is an inviting biological weapon for both armies and for terrorists because the perpetrators of the attack could protect themselves before hand by being vaccinated. Most people, including most people in The United States, are no longer vaccinated against this terrible virus, which continues to live on in select laboratories in The United States and in Russia (other countries too?).

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An electronmicrograph of the smallpox virus.

2. Bubonic Plague: Bubonic plague is most commonly spread from infected rats (and other critters) to humans via fleas but it can also be spread through the air, both intentionally in the case of a biological weapons attack or simply by coughing from a person with pneumonic plague — bubonic plague that has spread to the lungs. Bubonic plague results in the massive enlargement of lymph nodes to form pus filled sacks under the armpits, in the groin, and in the neck of persons afflicted with this deadly disease, which kills up to 90% of untreated victims. Antibiotics can cure bubonic plague if the infected person gets them quickly and if there are still enough antibiotics to go around, a rather important caveat if a large city or cities were to be infected simultaneously with this horrible pathogen. Victims of the bubonic plague often turn black due to disseminated intravascular coagulation (DIC), a coagulation disorder that can be triggered by an overwhelming infection. In DIC the body forms excessive blood clots, runs out of the clotting proteins that are necessary to form blood clots, and then bleeds internally. Again, bubonic plague is an inviting weapon for modern militaries and terrorist organizations because soldiers can be pre-treated with antibiotics before plague is unleashed.

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A man dying from bubonic plague, aka The Black Death.

3. Anthrax: The bacterium Bacillus anthracis is a ubiquitious soil organism that, as I stated above, probably lives in the soil in your backyard. This organism rarely naturally infects humans and when it does it usually presents as a nasty skin infection that afflicts persons who work with dirty animals (cutaneous/skin anthrax is also known as “wool-sorters disease”). The problem with anthrax is that it is easy to make and that when this bacterium is aerosolized in the form of a concentrated powder it rapidly produces a fatal pulmonary (lung) infection. Anthrax can be treated with antibiotics but, frankly, unless you get them into your system quickly even these modern drugs don’t work very well for someone with fullblown pulmonary anthrax. There is also an effective vaccine and all American soldiers, myself included back when I was still wearing the uniform, are vaccinated against this disease before they deploy overseas. The combination of anthrax being preventable with vaccination and with the preventative early use of antibiotics again make this a “good” candidate for use as a biological weapon. We all know that there have already been several lonewolf anthrax attacks in The United States, first after the Sept. 11th attacks (perpetrator likely deceased) and again in April 2013 (the targets were President Obama and US Senator Roger Wicker of Mississippi — perpetrator still at large). It is both easy to make for someone with Bachelor’s degree level microbiology training and deadly…

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One of the Sept. 11th anthrax letters, this one having been sent to Senator Tom Daschle (the Senate Majority Leader at the time).

4. Ricin: This biological poison exists in a gray area between biological and chemical weapons. Ricin is a naturally occuring toxin that is produced by castro beans and that can be distilled from them using fairly rudimentary chemistry techniques. Ricin has been used in assasinations, the most famous of which was the assasination of a Soviet dissendent in London during the 1970s via ricin that was administered by poking him with an umbrella with a concealed hypodermic needle in its tip. This powerful poison can also be disseminated through the air and their is no curative treatment for the havoc that it unleashes inside the bodies of its victims. Ricin works by shutting down the production of proteins inside the body’s cells and this rapidly causes tissues such as the lungs, the liver, the kidneys, and the gastrointestinal tract to stop working (to put it simply), with death as the result.

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Castor beans, the source of ricin.

5. Viral Hemorrhagic Fevers: Include the feared Ebola virus, which kills up to 90% of exposed people in a particularly gruesome way — by causing them to bleed both internally and externally, with blood oozing from every bodily orifice as the victim’s life slips away. These horrible viruses are found in nature and they have no effective preventative vaccination or postexposure cure. This likely gives viral hemorrhagic fevers too many potential unintended consequences for any sane military to consider their use — the risk of the virus circling back and infecting your own people would likely be too great (unless there is a vaccine or effective antiviral treatment that no one else knows about…). These same properties likely make viral hemorrhagic fevers a tempting weapon for terrorists who don’t mind losing their own lives in the process, especially for terrorists who hail from places that are unlikely to be reinfected via routine global transit — like terrorists who live in prehistoric villages in Afghanistan, the tribal regions of Pakistan, or the nether regions of Yeman for example.

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Dr. Leonardo Noto

Physician and Author of Medical School 101, Intrusive Memory, The Life of a Colonial Fugitive, and The Cannabinoid Hypothesis. Amazon Link to Doc’s Writing:  http://www.amazon.com/Leonardo-Noto/e/B00ATVOMCW/ref=ntt_dp_epwbk_0

NOTE: The Life of a Colonial Fugitive — my dark historical thriller — is free for your ereader at http://www.smashwords.com/books/view/215272. Thanks for reading!

Author Bio: Dr. Leonardo Noto is the nom de plume of a former airborne battalion surgeon who is now in civilian practice. Dr. Noto is the author of four books and he also writes for a medical education corporation that assists medical students, interns, and residents as they prepare for the medical board examinations. Dr. Noto is the proud father of an extremely spoiled 16-month-old American Bulldog who enjoys slobbering everywhere and tearing up things that he is not supposed to! Dr. Noto is an amateur practitioner of muay Thai and Brazilian jiu jitsu and he recently began learning to play the guitar (but he is currently a quite terrible musician, as his neighbors will readily attest).

Remember to discuss all health concerns with your personal physician (I don’t count!) before making any medical decisions. www.leonardonoto.com is intended to present general medical information for entertainment purposes and not as specific guide to any medical treatment. The author has made every effort to present accurate information; however, due to the ever-changing nature of medicine and the intrinsic caveats that are inherent in any particular case, no medical decisions should ever be made based on information gleaned from the internet (duh!). The internet and self-education are great, but they don’t replace your Doc!

The opinions voiced on this medical blog are solely the author’s own and they do not reflect the opinions or values of Dr. Noto’s employers, past or present. Dr. Noto’s medical blogs should never be used as supporting evidence for legal testimony — this is of course obvious to anyone who isn’t a complete moron, but some people are rather stupid.

References:

1. Emergency War Surgery: Third United States Revision. Department of Defense, United States of America. 2004.

2. Pickover, C.A. The Medical Book: From Witch Doctors to Robot Surgeons, 250 Milestones in the History of Medicine. Sterling Publishing, New York, New York. 2012.

3. Arms Control Association. http://www.armscontrol.org/factsheets/cbwprolif

4. Mann, C.C. 1491: New Revelations of the Americas Before Columbus.Knopf. 2005.

5. Riedel, S. Edward Jenner and the History of Smallpox and Vaccination. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1200696/

6. CDC: Facts About Ricin. http://www.bt.cdc.gov/agent/ricin/facts.asp

7. Poison Gas Attack: Courtesy of Wikipedia. http://www.google.com/search?as_st=y&tbm=isch&hl=en&as_q=biological+weapons&as_epq=&as_oq=&as_eq=&cr=&as_sitesearch=&safe=images&tbs=sur:fc&biw=1600&bih=728&sei=WFMlUu2RGMTlygHtsoCAAQ#as_st=y&hl=en&q=biological+weapons&tbm=isch&tbs=sur:fc&facrc=_&imgdii=_&imgrc=AUS5I1VchAloMM%3A%3Brz0CWPBHJlp6eM%3Bhttps%253A%252F%252Fupload.wikimedia.org%252Fwikipedia%252Fcommons%252F0%252F09%252FPoison_gas_attack.jpg%3Bhttp%253A%252F%252Fen.wikipedia.org%252Fwiki%252FChemical_weapons_in_World_War_I%3B713%3B262

8. Shiro Ishii/Unit 731: Courtesy of The Government of Japan and Wikipedia. http://en.wikipedia.org/wiki/File:Shiro-ishii.jpg. http://en.wikipedia.org/wiki/Shiro_Ishii.

9. Child with Smallpox: Courtesy of Wikipedia. http://www.google.com/search?as_st=y&tbm=isch&hl=en&as_q=biological+weapons&as_epq=&as_oq=&as_eq=&cr=&as_sitesearch=&safe=images&tbs=sur:fc&biw=1600&bih=728&sei=WFMlUu2RGMTlygHtsoCAAQ#as_st=y&hl=en&q=small+pox&tbm=isch&tbs=sur:fc&facrc=_&imgdii=_&imgrc=kK0fifoo49WX2M%3A%3BiNBHHMAvHy4RzM%3Bhttp%253A%252F%252Fupload.wikimedia.org%252Fwikipedia%252Fcommons%252F6%252F66%252FChild_with_Smallpox_Bangladesh.jpg%3Bhttp%253A%252F%252Fen.wikipedia.org%252Fwiki%252FFile%253AChild_with_Smallpox_Bangladesh.jpg%3B1995%3B3040

10. CDC: Evolution of Smallpox Vaccine Scar: www.bt.cdc.gov.

11. Gasmask: www.photopedia.com. http://www.google.com/search?as_st=y&tbm=isch&hl=en&as_q=biological+weapons&as_epq=&as_oq=&as_eq=&cr=&as_sitesearch=&safe=images&tbs=sur:fc&biw=1600&bih=728&sei=WFMlUu2RGMTlygHtsoCAAQ#as_st=y&hl=en&q=biological+weapons+&tbm=isch&tbs=sur:fc&facrc=_&imgdii=_&imgrc=IjTK3e2PVBxQeM%3A%3BBsUcnXtQGfx59M%3Bhttp%253A%252F%252Fimages.cdn.fotopedia.com%252Fflickr-2340497389-hd.jpg%3Bhttp%253A%252F%252Fwww.fotopedia.com%252Fitems%252Fflickr-2340497389%3B1620%3B1080

12. Smallpox Virus: http://www.google.com/search?as_st=y&tbm=isch&hl=en&as_q=biological+weapons&as_epq=&as_oq=&as_eq=&cr=&as_sitesearch=&safe=images&tbs=sur:fc&biw=1600&bih=728&sei=WFMlUu2RGMTlygHtsoCAAQ#as_st=y&hl=en&q=smallpox+virus&tbm=isch&tbs=sur:fc&facrc=_&imgdii=_&imgrc=t2MLkYzo_s_P1M%3A%3BWb1fAUxORmoNmM%3Bhttp%253A%252F%252Fupload.wikimedia.org%252Fwikipedia%252Fcommons%252Fd%252Fd4%252FSmallpox_virus.jpg%3Bhttp%253A%252F%252Fcommons.wikimedia.org%252Fwiki%252FFile%253ASmallpox_virus.jpg%3B700%3B529

13. The Black Death: http://www.google.com/search?as_st=y&tbm=isch&hl=en&as_q=biological+weapons&as_epq=&as_oq=&as_eq=&cr=&as_sitesearch=&safe=images&tbs=sur:fc&biw=1600&bih=728&sei=WFMlUu2RGMTlygHtsoCAAQ#as_st=y&hl=en&q=bubonic+plague&tbm=isch&tbs=sur:fc&facrc=_&imgdii=_&imgrc=vbas0_EVeECZMM%3A%3B4BQtgg5Tgf9DOM%3Bhttp%253A%252F%252Fupload.wikimedia.org%252Fwikipedia%252Fcommons%252F0%252F0a%252FAcral_necrosis_due_to_bubonic_plague.jpg%3Bhttp%253A%252F%252Fen.m.wikipedia.org%252Fwiki%252FFile%253AAcral_necrosis_due_to_bubonic_plague.jpg%3B331%3B504

14. Anthrax Letter: http://www.google.com/imgres?imgurl&imgrefurl=http%3A%2F%2Fanthraxmuseum.tripod.com%2Ftheanthraxmysterymuseumtm%2F&h=0&w=0&sz=1&tbnid=wHMn548pTuUnWM&tbnh=194&tbnw=259&prev=%2Fsearch%3Fq%3Danthrax%26tbm%3Disch%26tbs%3Dsur%3Afc%26tbo%3Du&zoom=1&q=anthrax&docid=4oNxDVLII1jjHM&hl=en&ei=dVwlUt3nGcq7qAGX2IHQBQ&ved=0CAUQsCU

15. Castor Beans: http://www.google.com/search?as_st=y&tbm=isch&hl=en&as_q=biological+weapons&as_epq=&as_oq=&as_eq=&cr=&as_sitesearch=&safe=images&tbs=sur:fc&biw=1600&bih=728&sei=WFMlUu2RGMTlygHtsoCAAQ#as_st=y&hl=en&q=castor+beans&tbm=isch&tbs=sur:fc&facrc=_&imgdii=_&imgrc=V8B0kVUzGBJvcM%3A%3B_71waOagMkhaPM%3Bhttp%253A%252F%252Fupload.wikimedia.org%252Fwikipedia%252Fcommons%252F3%252F3d%252FCastor_beans1.jpg%3Bhttp%253A%252F%252Fcommons.wikimedia.org%252Fwiki%252FFile%253ACastor_beans1.jpg%3B1234%3B1195

16. Bashar Al-Assad. www.flickr.com.