As I blog about drugs, poisons and various chemicals that can be used as murder weapons in murder mysteries, I’m constantly looking for unique methods of murder to use in my storytelling.
One of my more popular blogs has been the one I wrote about The Perfect Drug as a Murder Weapon. Today, however, I want to introduce you to an interesting method of murder that doesn’t involve any of those substances, yet it’s a most effective lethal weapon. It’s thin air!
An air embolism, officially called a vascular air embolism or VAE, was discovered in the early nineteenth century as lethal. Since that time, fatalities have been associated with the inadvertent introduction of air into a person’s vascular system during trauma or surgery. It occurs when an air bubble or multiple air bubbles enter a vein or artery and block it.
When these air bubbles travel to the brain, heart or lungs, they can cause fatal heart attacks, stroke and respiratory failure. A large bolus of air into a vein can lead to a right ventricular air lock and be immediately fatal.
The death scene from an air embolism can be very dramatic with descriptions of crushing pain in the chest, confusion and disorientation, irregular heart rhythms and skipped heart beats, extreme shortness of breath, and convulsions as air froths through the circulatory system. Death can occur in minutes.
There is continued debate regarding how large an air bubble is fatal to an average-sized
person. I’ve seen literature state as little as 50cc can be fatal. Other literature suggests that a much larger dose, around 150 to 200ccs (about the volume of a regular coffee cup) is needed to be lethal. Fatalities are dose-related and the air must be introduced into a vein or artery to be an effective killer.
One of the more intriguing aspects of murder by air embolism is that a writer doesn’t have to consider how the villain secures a chemical murder weapon. The weapon is everywhere, readily accessible and a large syringe is much easier to obtain than a lethal substance. It’s available from any medical supply company, a pharmacy, a veterinary clinic, a supply cart in a hospital, and the like.
Detecting an air embolism as the cause of death (COD) can be tricky since the lethal effects mimic a massive heart attack or stroke. It’s not easy for a medical examiner to determine the COD unless the professional is specifically looking for that telltale evidence.
There are several ways an astute medical examiner could determine that an air embolism is the cause of death. One method is called a trans-esophageal echocardiography. This method uses sound waves to detect air bubbles in the circulatory system. Another method is to insert an arterial catheter into the artery that connects the heart to the lungs. A change in blood pressure in the pulmonary artery indicates the presence of air. The problem is that air dissipates rapidly as a device enters the pulmonary artery and evidence is lost.
I used an air embolism, via an air-filled syringe, as a murder weapon in my current novel 
Lethal Medicine because of the dramatic murder scene that could be constructed around the murder. For the method of detection, I decided that the medical examiner would X-ray the body to detect air in the circulatory system, particularly the pulmonary arteries. It was important to me that the evidence should be found specifically that way since once the body was opened and the circulatory system exposed, the evidence presumably would be lost.
Writing dramatic murder scenes takes a bit of research and imagination to come up with the perfect lethal weapon that fits into your storyline. Take the time to do that well and you’ll have a killer murder scene.
Thoughts? Comments? I’d love to hear them!
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Read about other methods of murder that I use in my current novel Lethal Medicine
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Prescription For Murder 
Yeah, this is a good one for fictional murder.
Great idea!
But what about the injected spot on body? how it can be avoided?
No way to avoid a needle injection site if you’re trying to access a vein – and you’ll have to. BUT I used this method in my debut novel LETHAL MEDICINE and the person was already hooked up to an IV hydration so the air was added to an injection port on the tubing.
Antonin Scalia? Probably, but we’ll never be able to prove it.
True, no way to prove that without an autopsy or an X-ray of the pulmonary artery to detect air bubbles.
That was used very effectively in the 1978 movie Coming Home with Jane Fonda and John Voight. Billy, the brother of a friend of Fonda’s character, emotionally disturbed by his war experiences, commits suicide by injecting himself with air. I don’t know if the death was realistic, but it seemed awful enough.
An air embolism is certainly a painful way to die. Nurses and doctors who place central IV access lines are careful to bleed back the air out of a newly-placed line before flushing it with saline. And nurses who give bolus injections to patients are careful to flick the air bubbles out of a syringe before giving intravenous injections for that same reason.
Thanks for your comments!
I was taking care of my mom when she was suffering from stage 4 gallbladder adenocarcinoma with bilobar liver metastasis and spreaded to few lymph nodes. She was having two antibiotic iv salines, each of 100 ml. During the infusion after the first bag got empty, the tube quickly started to empty and I did not know that it was necessary to prime the tubing, I plugged the second bag of iv saline. And may be almost all the air in the tube (almost 10 ml) went into her peripheral vein. She immediately felt chest pressure after a few minutes. So I got scared and called in doc. Her blood pressure went reallly high(145/95) and saturation level lowered (85%), though she had no prior heart or pulmonary issue other than tachycardia. 100% oxygen was administered immidiately after then with a nasal cannula for a minute and then she felt fine. An ecg was also done after that and the only change that was seen in the ecg compared to the previous one done a month ago, was incomplete right bundle branch block. Docs told me that there is no issue found in ecg. So, I also thought that nothing will happen. The next day in morning, I found her feet swelled. But I though it would go away within days, because my mom had previously lot of times legs swelling, but they would ultimately go away after a few days. She also told me that she could not sleep at night, though she was taking morphine. Also later that day, she told me that she felt pain in her abdomen severely. I thought all were due to the cancer. And taking meds would make her comfortable. But after a few days, she was gasping for air, tried to go from one room to another and suddenly she had loose motion during bowel movements and went to toilet for more than 4 times within a few hours. So i stopped giving laxatives and milk from that day. And after a day her eyes went yellow, and urine darkened and her feet, legs and abdomen swelled so much that she couldn’t even move and lost control of her mind and always kept her eyes half-open,she even didn’t want to lay down. Then I took her to ER and the docs found her blood pressure 140/90 and saturation level at 73%. After 3 days she died with cardiac and respiratory failure.
I have read a lot of journals since then regarding air embolism and almost all of them states that less than 1-3 ml/kg is harmless. But i have seen my mom die within 10 days of 10 ml iv air embolism, and how her health deteriorated sooner than expected.
Thanks for that information and thanks for sharing. So sorry for your loss.