When we read mystery novels, we often encounter many descriptions of murder. How to make these cases ingenious, fascinating and scientific enough to prevent die-hard readers from catching insects is a problem that many novelists are worried about. In the recently published book Forensic Medicine, Police and Crime Scene: 2 16 Strange Questions, many novelists put forward some plot settings with wide brain holes. Can these plots be realized in real life? Please read the answer of Douglas Lyle, an American doctor of medicine and best-selling author, and the interpretation of @ Shantou Laoyao, a famous netizen in the field of forensic medicine. Pictures and texts may cause discomfort, please read them carefully. This paper only discusses the science behind the plot of the novel from the perspective of forensic medicine, so please do not imitate it.
Is there any way for nurses to kill people by injecting air?
Q: I think one of the nurses in the story is a serial killer. It is said that injecting air into veins or arteries can kill the target, which looks like a heart attack. If this is true, how much air should be injected? Where will the injection not be seen through or make the forensic doctor suspicious and judge it as a natural death? How long before the victim dies? Questioner: Linda F Ames, Columbus, Georgia.
A: Injecting enough air can achieve the goal. Simply injecting a bubble into the vein or vein tube of the hospitalized patient will not be a problem. Bubbles will only pass through the right side of the heart, enter the lungs and be filtered there, which will not attract the victim's attention at all. But if there are many injections, the situation is different.
This condition is called air embolism. The air composition must reach 100 to more than 200 ml to die. For reference, a cup is about 240 ml. If this amount of air is injected quickly, it will quickly move to the right side of the heart and stop the pumping action. How did this happen? Blood is a liquid and cannot be compressed. When the right ventricular myocardium contracts (squeezes), liquid blood is squeezed out and enters the lungs. Air can be compressed. If the right ventricle is filled with air, the bubble will not move forward when it is squeezed, but stay in its original position and be compressed into a smaller volume. It's a bit like an air plug, which will hinder the blood flow and may lead to cardiac arrest, which will lead to death in less than a minute or two.
Bubbles on the right side of the heart. Air will enter the heart, causing air lock. A beating heart will crush large bubbles into small bubbles, and small bubbles entering smaller blood vessels may affect blood circulation. Then the image source: safeinfusiontherapy.com
Air must be injected into veins, any vein can be used, because all veins eventually flow into the right side of the heart; It is useless to inject into the artery, because the artery will guide the blood away from the heart. Your nurse killer can also use an intravenous tube that has been placed on the victim.
Such a fatal case really looks like a heart attack (myocardial infarction). However, if a forensic autopsy is performed-this kind of sudden hospital death is usually performed-he will see a mass of air in the right ventricle and know that the air is artificially injected. Because hospitalized patients generally have needle eyes and veins, he may not know where the air is injected; But at the same time, it is also a hint, which can let him know who injected air, whether it was intentional or accidental. It's up to your agent to find out.
Jing Jing Jing Jing Jing: Regarding the method of air embolism death, this paper introduces the principle of death, as well as the amount and location (vein) of air to be injected. At the same time, the article also pointed out that forensic doctors can find the real cause of death in autopsy. This is instructive for those who try to inject air. At the same time, I don't think this kind of inspiration is particularly helpful, because it is difficult for ordinary people to insert the needle into the vein accurately, and if they can't get the needle, they have to stick another needle, so this method is not practical at all; If you are a medical worker who can successfully prick the needle (the legendary hit the nail on the head), you don't need the inspiration of this article at all. People have said this question a hundred times when they were in nursing school-the evidence is that doctors and nurses will squeeze a few drops of medicine from the needle in front of them in order to expel the bubbles that may be mixed in, so they have long known this method.
How do medical staff perform CPR on a helicopter?
Q: A military doctor saved an injured person on a helicopter supporting medical evacuation. The injured man's heart stopped beating. If he was wearing a kevlar bulletproof vest pierced by shrapnel, where would the military doctor insert the electrodes of the defibrillator? Questioner: Michelle Gagnion's best-selling books The Gatekeeper and Kidnapping &; Ransom) author
A: It's not easy to perform CPR on a helicopter, but there won't be too many obstacles. Kvira vests are more flexible than the bulletproof vests with metal or ceramic armor in the past, so it is impossible to hold down your chest if you wear an old vest. He is wearing a Covila vest, which can press his chest. Chest compression is the initial measure. You can do it while waiting for the defibrillator to be ready.
During cardiopulmonary resuscitation, defibrillators are usually used to correct abnormal heart rhythm, especially ventricular tachycardia or ventricular fibrillation. Most defibrillators have electrode patches or palm-shaped electrode plates, which must be in contact with the skin and placed on opposite sides of the heart. Therefore, when current is conducted from one electrode plate to the other, it can pass through the chest and heart.
Usually, electrode plates or electric shock patches will be placed on the right chest and left armpit. According to your plot, because the vest will block the normal placement position, one patch or electrode plate can be attached to the right shoulder or neck, and the other can be attached to the upper left of the lower abdomen, so that the current can pass through the heart-in fact, this is a sufficient condition for completing the electrical cardioversion (the procedure from abnormal heart rhythm to normal heart rhythm). Military doctors can avoid bulletproof vests and finish their work.
Usually, the electrode plate or electric shock patch will be placed on the right chest and left armpit (pictured). If the patient wears a bulletproof vest, one patch or electrode plate can be attached to the right shoulder or neck, and the other is attached to the upper left of the lower abdomen, so that current can pass through the heart to complete cardiopulmonary resuscitation. Image source: Wikipedia
How to murder a patient with severe emphysema to make him look like suicide or accidental death?
Q: A 70-year-old man suffers from severe emphysema. His daily life depends on wheelchairs and oxygen cylinders. What should a bad guy do if he wants to kill him and it looks like suicide or accidental death? Can he just take the oxygen bottle or destroy it? Questioner: Simon Wood is the author of The Piper's ransom and other works in the California Bay Area.
A: Many patients with emphysema really need all-weather oxygen supply and carry small oxygen cylinders or oxygen concentrators with them. In any case, the oxygen content of the air inhaled by the patient from the oxygen supply device is slightly higher than that of the indoor air. Taking his oxygen bottle or concentrator, or releasing oxygen, there is indeed a possibility of death, and it is impossible to say whether it is an accident or suicide.
Many patients with emphysema need to carry oxygen bottles with them to ensure oxygen supply all day. Image source: youandmemagazine.com
Another way is to increase the amount of oxygen he breathes. Let me explain: emphysema, like other patients with chronic obstructive pulmonary disease, is very sensitive to oxygen inhalation. The physiological principle is extremely complicated, but for people with this disease, if the oxygen content in the inhaled air is extremely high, the brain stem respiratory center will be severely depressed, feel sleepy and fall into a coma, and finally suffocate. This will be a more pleasant way to commit suicide. If the oxygen intake is reduced, it will lead to serious breathing difficulties and make him suffer great pain before he dies; Increasing oxygen intake will make him fall asleep, fall into a coma and die peacefully.
If the bad guys return to the scene afterwards and return the oxygen cylinders to normal flow, it is impossible to determine the mode of death. In other words, homicide, suicide, accidental death and natural death of COPD all look the same. The normal flow rate of this oxygen cylinder is about two liters per minute. If the flow rate is increased to four to five liters per minute, it may be fatal in a few minutes or an hour at the longest.
@ Jingjing Jingjing Jingjing Jingjing: The original author emphasized the possibility and result of this death in the case of transferring oxygen cylinders, but it is a bit exaggerated to say that it is impossible to distinguish homicide, suicide and natural death. The forensic doctor can judge whether the death is caused by lack of oxygen from the painstaking efforts of the deceased. Of course, whether this hypoxia is caused by external forces or pathological reasons must be judged by combining other evidence. In fact, it is not particularly rare for the public to commit murder by tampering with oxygen cylinders, even if it is not aimed at emphysema patients. Therefore, if someone really wants to do this and has access to the oxygen cylinder switch, he will not be suspected. Even if he has not read this article, he can still commit this kind of murder.
How can a woman strangled by a cello string be hurt?
Q: One of my characters stood behind the object he wanted to murder and wrapped a cello steel string around her neck. He wants to prolong the time of this move, so the force applied is only enough to scare her; When he made up his mind, he finally pulled hard and it was over. What will happen? Will the cello string be fatal to the neck, or will it only cause suffocation? I want to describe the blood spatter, but I must be realistic. Can the forensic doctor infer the tools used by the murderer? Like finding rosin in a wound? Questioner: P.J. parrish won the Shamus Prize, the Thriller Award and the Anthony Award, and was nominated for the Poe Prize. Fort Lauderdale, Florida and Toki, Michigan.
A: Cello strings can be used as throat wringing tools, but they can't be tied like strings. When using stranded wire, gloves are basically put on, and the wire coil is wound on the palm of your hand or on the handle made of wood, metal and other materials. It works in different ways, because the ring will cut into the meat, but the rope or rope will not; The bruises and knife wounds left on the victim's neck will be horizontal, and the wounds in the front will be deeper than those in the back, so the forensic doctor can judge that the murderer is standing behind the victim.
Because the murderer strangled and tortured the victim many times before hurting the murderer, he always left a bloodstain line roughly matching the thickness of the strings. Finally, when he pulls the handles at both ends, the rope will cut into the meat and cut off the carotid artery and/or jugular vein. At least you can do it. If an artery is cut off, there will be a lot of bleeding, pulsation and splashing a few feet away; Venous amputation can also cause considerable bleeding, but it will not splash. The killer may have cut off an artery and a vein, but the other side was not affected. Besides, you can arrange any combination you want.
The picture below may cause discomfort.
In the American drama Hannibal, the cello once again appeared in the murder case. This time, the victim was directly transformed into a cello. Image source: galleryhip.com
The forensic doctor will examine the bruises and the width of the incision to determine the thickness of the throat ring used by the murderer. If we can find the equipment suspected of murder, we can determine whether it matches the wound. However, even if the width is the same, it cannot be asserted that the instrument is the murder weapon, only that it is possible, or a similar turning point. On the other hand, if the forensic doctor finds blood on the strings and the DNA matches the victim, then it can be determined that this is the murder weapon.
Yes, the forensic doctor may find a foreign body on the surface or inside of the victim's wound, which is confirmed to be beaded rosin after inspection.
@ 个丫丫丫丫丫丫丫丫丫: For serial killings, this article mainly introduces the possible causes of injury and death. This method will almost certainly be regarded as homicide by the forensic doctor.
Can patients with synonymy conversion disorder take care of themselves?
Q: The protagonist in my novel is suffering from transformation-cognitive paralysis. He must be in a wheelchair and can't walk. She is rich, has a domestic helper and can live independently and actively, but still needs the help of a powered wheelchair and an auxiliary dog. She also strengthens her physical strength through fitness. How far can she take care of herself without other people's help? I assume that she wants to do everything by herself, but can paraplegics really manage to get out of the wheelchair, get out of bed, take a shower and go to the toilet without help from others? Does she have to rely on external forces to solve personal care problems, or can she take care of herself completely? If she is pulled out of the wheelchair for some reason, is there any way for her to pull herself back to her seat? Questioner: Diane M. Donner, Charlotte, North Carolina.
A: Sympathetic nerve conversion reaction is a mental disorder, not a physical disorder. This is not paraplegia, paraplegia is paraplegia caused by spinal cord injury. Patients with conversion reaction do not have this neurological defect. They can do anything, including running, jumping, showering, eating, dressing and so on. But they just don't do it on purpose. Or more accurately, it is their mental illness that makes them choose not to do it.
People with this disease tend to sit still and stare at the people around them, but they are indifferent. They don't walk around or do fitness activities in electric wheelchairs. They look depressed and are not interested in anything. She won't have an auxiliary dog, because even that dog is likely to be ignored. She can climb back into the wheelchair and do anything she wants. Don't forget, this is a mental illness, not a physical disorder.
This reaction can also be seen in patients with mental illness such as schizophrenia, which is common in cases of severe psychological trauma. In the latter case, they are usually self-limiting, which means that this reaction can be alleviated without special treatment. Usually it only takes a few days or weeks, but in some rare cases, it will last for months or years.
So your character can do anything, but she may not mean it. If she refuses to do so, she may need someone else to help her with personal care.
-The above article is taken from forensic medicine, police and crime scene: 2 16 strange topic.
Author: [America] Douglas Lyle
Press: Democracy and Construction Press
Publication year: 20 14- 12- 1
Thank you @ Shantou Laoyao for your wonderful comments on this article.