Sucking Chest Wounds
Patrick O’Neil, PA
A Sucking Chest Wound, or Open Pneumothorax, is one of the more common injuries that was seen in previous wars, and also one of the more deadly. With the advent of better body armor, we now see fewer of these injuries on the battlefield. In the civilian sector; however, we are seeing more of these injuries than ever before. Gunshot wounds, large knife wounds, and even the occasional blast injury can easily cause one of these injuries. There are even videos on YouTube of a sucking chest wound from a dog bite.
What Causes a Sucking Chest Wound or Open Pneumothorax?
A Sucking Chest Wound arises from a large defect in the chest wall. You basically have an opening that communicates from the outside, through the skin, fat, muscle, ribs, and thoracic cavity. Once that opening is ¾ the size if the trachea (wind pipe), the air will want to enter the chest cavity from the open wound, instead of through the mouth.
In basic terms, think of it as inefficient mechanics of breathing. When we take in a breath, the diaphragm causes the lungs to expand by applying a negative pressure inside the chest cavity. This negative pressure causes air to rush into the lungs from the mouth or nose, down through the trachea, past the bronchi and into the lungs. When we are ready to exhale, the diaphragm presses on the lungs and a positive pressure is created which forces the air out of the lungs and through the mouth or nose.
When we have a defect in the chest wall greater than ¾ the diameter of the trachea, the air now wants to enter through the chest wall opening. It is a much shorter distance to travel and it would rather come in from the chest wall than through the mouth. You will have a small amount of air entering through the mouth, but not anywhere near the volume it receives in a normal breath. When the air is passing through the chest wall you will hear the “sucking” or “hissing” sound that is common to these types of injuries.
In these types of injuries, the patient is suffocating from lack of air getting inside the lungs, exchanging the Carbon Dioxide for Oxygen, and then perfusing the organs with that oxygen.
Signs and Symptoms
► An obvious defect in the chest wall with the prototypical “sucking” or “hissing” sound
► Rapid breathing
► The chest wall is not expanding as much as it normally would
► Breathing is very shallow
► Breathing is very labored
► The wound may be visibly bubbling
► Decreased breath sounds
► Tapping on the chest wall may elicit a drum-like sound
► In late stages, the patient’s lips, ears, nose may start turning blue from lack of oxygen
The treatment goal is to seal the defect in the chest wall so the air will want to enter through the mouth or nose.
We do this through several methods:
► A chest seal with a one-way valve can be placed over the opening in the chest. This will allow the valve to seal as the patient inhales, forcing the outside air to enter through the mouth/nose and pass into the lungs. On exhalation, the valve will open to allow the air trapped in the chest cavity to be evacuated. It will not inflate a collapsed lung, but it will possibly prevent the condition from worsening.
► A Needle Thoracentesis can be performed where a 14 gauge, 3-1/4 inch needle is placed just above the second rib in the anterior chest. Placement will allow excess air to escape, but should only be performed by those individuals that have been trained in how to perform this invasive procedure. This method will also not inflate the lung.
► The gold standard to treat a Sucking Chest Wound/ Open Pneumothorax is a chest tube placed into the thoracic cavity and hooked up to low pressure suction. Naturally this is done after all openings have been adequately sealed. The chest tube with suction will evacuate the unwanted air and blood from the chest cavity. It also has the very important advantage of being able to inflate the collapsed lung.
► If you have oxygen available to you, get it started. Remember, this patient is suffering from lack of oxygen into the lungs and throughout all the tissues of the body.
When to seek medical attention?
Immediately!!!! But this is pretty much a “no brainer” for most people. Call 911 and then start treating the injury. We call 911 first because it is very easy to get started treating a patient and then a few minutes go by and we still haven’t made the call. Get the Paramedics rolling to your location while you treat the patient; or, worst case scenario….yourself. Time is critical!