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Public use of chest seals

As most of you know, we are based in Philadelphia. Philadelphia has recently seen an upswing in violence. So far, the city is on track to end the year with over 450 homicides. In order to help with this new health crisis, we recently did a “Stop the Bleed” program at a community event. Stop the Bleed is a program that teaches non-medical people how to treat severe bleeding using direct pressure, tourniquets and wound packing. I love that the Stop the Bleed brings medical knowledge to people that could be first on scene even before 911 is called. However, there is one skill that I feel most civilians need to know that isn’t taught in most programs, and that is chest seals.


We know that in the general public, trauma is the leading cause of death between ages 1-44 and that bleeding is the cause in approximately 80% of these cases. It makes sense that stopping bleeding is definitely a lifesaver, but we need to look at the differences in accidental and intentional trauma. It's easy to understand that in accidental trauma, our extremities (arms and legs) are generally the most affected body parts. It’s probably safe to say that the last time you cut yourself cooking, it was probably a hand or finger and you didn’t accidently stab yourself in the chest or neck. This is a bit different in intentional trauma. Most people looking to inflict harm on someone will most likely target the vital organs like the brain, heart and lungs. Studies have shown that most people who die in a mass shooter event are killed by injuries to the chest and head. We also need to remember the path that trauma medicine took to get to the bystander level. Programs like Stop the Bleed have origins that started on the battlefield and then transitioned to public safety/law enforcement and eventually to the public. Many of the initial studies that looked at how the skills in Stop the Bleed programs could be used to save lives came from combat environments. In these studies, the leading cause of preventable death was uncontrolled extremity bleeding. Many of the life-saving efforts that came out during that period looked at the military data and carried it over to the civilian world but overlooked some of the main differences between combat and civilian settings. One of the more obvious differences is our service people have body armor that protects the chest. They also overlook the fact that most civilian acts of violence occur at a much closer range than military combat. At the time, there were very studies on civilians treating trauma in the civilian setting. Based on this information, we need to look at what we need to do to treat these different types of injuries from intentional harm.

Before I get into what a chest seal is and how it is used, I thought it would be best to discuss why they are important. First, we are going to define the area we are talking about. When it comes to thoracic injuries, we are going to consider the chest anything between the belly button and the neck, front and back and excluding the arms. We need to look at the chest cavity as a negative pressure system. As our diaphragm (the muscle that controls our breathing) contracts and gets smaller, it increases the vacuum inside of our chest cavity . As this negative pressure increases, it forces our lungs to inflate. This is a lot like a balloon in a vacuum chamber:

As our lungs inflate, air is drawn in through the opening that is our airway. The diaphragm then relaxes and increases the pressure in our chest cavity and forces the air out of our lungs. This process is known as ventilation.

When there is an injury to our chest, a few things may end up happening. All of these can result in death to an injured victim.

  1. First thing that could happen is that there is a hole in our chest. If this happens, it can allow air into the chest cavity. As we learned above, this will prevent our lungs from inflating and cause our lung or lungs to collapse. It may look like the injured person is breathing, but there is very little air moving in and out of the lungs. You may hear the air entering the injury. This is where the term “sucking chest wound” comes from. The buildup air in the chest cavity is called a Pneumothorax. (It’s Latin for Air in the Chest; Pneumo meaning air, Thorax meaning chest).

  2. Second thing that is a possibility is that the pressure builds up in the chest cavity. This is even more dangerous because besides preventing air from entering the lung, it can build up enough pressure to prevent our heart from pumping properly. This condition is known as a tension pneumothorax.

Based off of this simple anatomy lesson, I hope that you recognize that the treatment for these 2 conditions is to prevent air from entering the chest cavity. This is where the chest seal or occlusive dressing comes in.

Chest seals are as simple as they sound. Commercial chest seals are adhesive devices that simply prevent air from entering the chest cavity. Some are available with vents that prevent air from going in but allow excess pressure to escape from a one-way valve. Chest seals are inexpensive devices and typically range from $10 to $20. It is also important to note that improvised chest seals can also be effective. To improvise a chest seal, you can take any airtight material like a bandage wrapping, shopping bag or even duct tape and secure it over the injury. Another improvised chest seal is an Automatic External Defibrillator (AED) pad. AEDs are often found in public places and are used for treating cardiac arrest patients. Ideally, your choices in chest seals would be:

  1. Commercial vented chest seal

  2. Commercial non-vented chest seal

  3. Improvise (make) a chest seal


Applying a chest seal is an easy process that can be done by anyone. The steps for chest seal application are:

  1. Call 911 or your emergency number. Do not assume that someone else has called. In many cases if there is a crowd, yelling “Call 911” will not work because people will make the assumption that someone else will call. If you are starting first aid and want someone to call 911, tell someone specific to call. Be prepared to give your location, the number of patients and what happened. Listen to the 911 call taker and give them all of the information they ask for in a clear and concise manner. The sooner the call taker gets the required information, the sooner they can dispatch the appropriate responders.

  2. Make sure that it is safe for you to treat the injured person. It does not help anyone if you get injured trying to render aid. If the scene is not safe, DO NOT risk getting injured or killed trying to provide first aid.

  3. Treat any massive extremity trauma first! The body not getting oxygen does not matter if there is not any blood to transport the oxygen.

  4. Identify the injury. We are looking for any penetrating injuries on the torso between the neck and belly button. Keep in mind that with injuries from firearms there may be an entrance and exit wound. Exit wounds are typically larger than entrance wounds. Some wounds may be hard to find as they may be hidden in places like the patient’s arm pits, skin folds etc. Use clues like holes in clothing to help you find the injuries. If you are not sure if an injury is deep enough to reach the chest cavity, err on the side of caution and consider it life-threatening.

  5. Dry the area the best you can. Injured people may have fluids like blood, sweat or water on their skin that can prevent your chest seal from forming an air-tight seal. Many of the commercial devices have gauze to dry the skin. The gauze is ONLY for drying the skin and is not a part of the chest seal.

  6. Prepare your chest seal. On a commercial device, this means exposing the adhesive. If you are improvising or making a chest seal, this means finding an airtight material and a way to secure it in place. You can use duct tape, medical tape or, in a worst-case scenario, use your hand to hold the airtight material in place until help arrives.

  7. Wait for the patient to exhale. This is the best time to seal the wound. When someone exhales, the diaphragm is relaxed. So, that is typically when the chest cavity has the least amount of air.

  8. Place the seal over the wound. Try to center the seal over the injury during placement. Ideally, you want the chest seal to be at least 2” larger than the injury on all sides. If you are using a commercial device, press the device down gently to get the best seal. For an improvised device, we want to tape it down on all 4 sides. (NOTE: This is an ongoing debate within the medical community. Some people will tell you to tape it on 3 sides to form a vent. While this makes sense, it is more important to prevent air from entering the chest cavity. Studies have also shown that taping on 4 sides is faster and easier for most people)

  9. Place the patient in the recovery position. Ideally you would place them with the injured side down.


10. If the patient develops increased trouble breathing, make sure that you didn’t miss any chest injuries. It is also possible the lung is damaged and is releasing air into the chest cavity. If you think that pressure is building up, you can “burp” your chest seal to release air by pulling up a corner of your chest seal. Ideally this would be done as the patient exhales.

11. When responders arrive, be prepared to tell them what injuries you found and what treatments you did.


Chest seals are amazingly simple, cheap and effective. Applying a chest seal to someone with a chest injury has the potential to save a life. No one should be afraid to use this device; it won’t cause any harm if the patient doesn’t have a pneumothorax. Many states have a Good Samaritan law that prevents a bystander who treats an injured person from getting sued or getting in trouble. I definitely recommend that you add a chest seal to your first aid/trauma kit.


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