Chest Trauma: Tension Pneumothorax, Sucking Chest Wounds, Flail Chest and Tamponade

Chest injuries kill quickly because the chest holds the two things a patient cannot do without for long: the lungs and the heart. Several of the deadliest chest injuries can be recognized from the mechanism and a handful of findings, and a few of them can be treated in the field. This guide covers pneumothorax in its simple, open and tension forms, chest seals, flail chest, hemothorax, rib fractures and pulmonary contusion, and cardiac tamponade, and how to tell them apart.

How the chest works, briefly

Each lung sits inside its own side of the chest, lined by two thin layers of pleura with a potential space between them. Breathing in, the diaphragm and chest wall pull outward and the pressure in that space falls below the pressure of the air outside, so air flows into the lungs. Anything that lets air or blood into the pleural space, or stops the chest wall moving as one piece, interferes with that. Anything that squeezes the heart or the great veins from outside stops blood getting back to the heart, which is obstructive shock, described in our Perfusion and Shock guide.

Simple pneumothorax

A pneumothorax is air in the pleural space. The lung on that side partly collapses. In trauma it usually follows a broken rib or a penetrating wound; it can also happen with no injury at all, classically in a tall, thin young adult or a patient with lung disease. The patient typically has chest pain that is worse on breathing, shortness of breath, and diminished breath sounds on the affected side. Vital signs may be close to normal.

A simple pneumothorax is not under pressure and does not by itself stop blood returning to the heart. The reason it matters in the field is that it can become a tension pneumothorax, and positive-pressure ventilation, from a bag or a ventilator, makes that more likely and faster. A patient with a suspected pneumothorax who needs assisted breathing needs close, repeated reassessment.

Tension pneumothorax

In a tension pneumothorax, air keeps entering the pleural space and cannot leave, acting like a one-way valve. Pressure builds on the injured side, collapses that lung completely, and pushes on the heart and the great veins. Blood cannot return to the heart, cardiac output falls and the patient goes into obstructive shock. Left untreated it progresses to cardiac arrest. It is one of the reversible causes of arrest in trauma.

Subcutaneous emphysema, a crackling feeling under the skin of the chest or neck as air tracks into the tissues, can accompany a pneumothorax of either kind. On the capnography waveform, a falling EtCO2 with unchanged ventilation can reflect a falling cardiac output, which our capnography guide describes in general and which is one more reason to reassess a patient with a chest injury often.

Needle decompression

The field treatment for a tension pneumothorax is decompression: releasing the trapped air so the lung can re-expand and blood can return to the heart. Needle decompression is within paramedic scope in many systems under protocol. Which needle, which insertion site and which technique you use are set by your protocol and your training, not by this guide. In the national EMS scope of practice model, needle decompression is a paramedic skill and not an EMT skill, and states can differ, so check yours.

For an EMT, the work on a suspected tension pneumothorax is recognizing it early, burping a chest seal if one is in place, supporting breathing without over-ventilating, requesting ALS where that is available and quick, and moving toward definitive care without delay. Telling the receiving facility what you suspect is part of the treatment.

Open pneumothorax: the sucking chest wound

An open pneumothorax is a wound through the chest wall that lets air move in and out of the pleural space. When the patient breathes in, air can be drawn through the wound rather than through the airway, and you may hear a sucking sound or see blood bubbling at the wound with each breath, which is where the name sucking chest wound comes from. The lung on that side collapses and breathing becomes inefficient. A wound may not suck audibly and still be open, so treat any penetrating wound to the chest, the upper abdomen or the back between the shoulder blades as possibly involving the chest.

Chest seals and occlusive dressings

• Cover the wound immediately, with a gloved hand if that is all you have, while a dressing is prepared.
• Apply an occlusive dressing: a commercial chest seal, or an improvised airtight material such as the plastic wrapper of a dressing, sealed on all sides.
• A vented chest seal has a one-way valve that lets air escape from the chest but not enter it. The Tactical Combat Casualty Care (TCCC) guidelines prefer a vented seal where one is available, and many civilian protocols follow that.
• A non-vented seal closes the wound completely. It stops air entering, but air leaking from the injured lung can still build up underneath it.
• The three-sided dressing, taped on three sides so the fourth acts as a flutter valve, is older teaching that some programs still show. Use the dressing your protocol names.
• Look for an exit wound and seal that too, including on the back.

Burping a chest seal

Sealing an open chest wound can turn it into a closed one, and if the lung underneath is still leaking air, a tension pneumothorax can build behind the seal. If a patient with a sealed chest wound develops worsening breathing, difficulty ventilating or signs of shock, lift one edge of the seal to let the trapped air escape, often called burping the seal, then reseal it. A vented seal can clog with blood and need the same thing. If burping does not relieve it, treat it as a tension pneumothorax under your protocol.

Flail chest and paradoxical movement

A flail chest is a segment of chest wall that has broken free from the rest, usually defined as two or more adjacent ribs each broken in two or more places. The free segment no longer moves with the chest. It moves the opposite way: drawn in when the patient breathes in and pushed out when they breathe out. That is paradoxical movement, and it is why some programs add a second P for paradoxical motion to DCAP-BTLS.

• Look at the chest wall with it exposed, from the side and at eye level if you can, and feel for crepitus and an unstable segment.
• Early on, muscle spasm can hold the segment still and hide the paradoxical movement. It may appear later as the patient tires.
• The bruised lung under the segment, a pulmonary contusion, is usually the greater threat. It is what makes these patients hypoxic, and it can worsen over hours.
• Pain makes the patient take small breaths, which worsens hypoxia. Pain management is your protocol's.
• Taping or sandbagging a flail segment is no longer recommended, because it restricts breathing further. Assisted positive-pressure ventilation, when breathing is inadequate, splints the segment from inside. Do not over-ventilate.

Rib fractures and pulmonary contusion

A broken rib is painful and the patient often breathes shallowly and holds the injured side to protect it. In a young adult a single broken rib may be a minor injury. In an older patient, rib fractures are serious: shallow breathing and a weak cough lead to pneumonia, and the risk of complications and death rises with the number of ribs broken. Fractures of the first or second rib take a lot of force and suggest other serious injuries. Fractures of the lower ribs are a clue to injury of the liver on the right or the spleen on the left. Do not wrap or bind the chest.

A pulmonary contusion is a bruise of the lung itself: bleeding and swelling in the lung tissue that interfere with oxygen exchange. It often accompanies a flail segment or multiple rib fractures, though it can occur without a fracture, especially in children, whose chest walls are flexible. Hypoxia can be mild at first and worsen over hours, so a patient who looked well on scene may not stay that way.

Hemothorax

A hemothorax is blood in the pleural space, from injured lung, chest wall vessels or the great vessels. Each side of the chest can hold a large share of the circulating volume, so a hemothorax causes both a breathing problem and a bleeding problem. Look for diminished breath sounds on the affected side with the signs of blood loss: a fast heart rate, pale, cool and clammy skin and, later, low blood pressure. The neck veins are usually flat rather than distended, which helps separate it from a tension pneumothorax. Air and blood together, a hemopneumothorax, is common after trauma.

There is no field treatment for the bleeding inside the chest. The prehospital job is to support breathing and oxygenation, treat for shock, keep the patient warm and get them to surgery quickly. Any fluid, and any blood pressure target, is your protocol's.

Cardiac tamponade

Cardiac tamponade is blood or fluid in the sac around the heart, squeezing the heart from outside so it cannot fill. In trauma it most often follows a penetrating wound between the nipples or between the shoulder blades, from the collarbones down to the bottom of the rib cage. The classic finding is Beck's triad: low blood pressure, distended neck veins and muffled heart sounds. Most patients with tamponade do not show all three, and a trauma patient who has bled elsewhere may have flat neck veins.

Think of tamponade from the mechanism and from shock that is not explained by visible bleeding. A fast heart rate, a pulse that weakens when the patient breathes in, and pulseless electrical activity all support it. Clear and equal breath sounds help separate it from a tension pneumothorax. Draining the pericardium is outside the scope of most EMS systems, so the EMS job is early recognition, support, early notification and fast transport. Our Beck's Triad guide covers tamponade in detail.

Telling them apart

Two more injuries to keep in mind

• Blunt cardiac injury: a direct blow to the front of the chest, such as a steering wheel, can bruise the heart muscle. Look for dysrhythmias on the monitor, and put a patient with significant chest impact on the monitor.
• Traumatic aortic injury: sudden deceleration, such as a high-speed head-on collision or a fall from a height, can tear the aorta. Many of these patients die at the scene; survivors may have few signs. A difference in pulses or blood pressures between the two arms or between the arms and the legs, or chest or back pain after that mechanism, is a reason to suspect it and to say so to the receiving facility.

When to suspect a chest injury

Field priorities

The principles below are taught across EMS curricula. How each is carried out, and every procedure, fluid and medication, is set by your protocol, your scope and your medical direction.

• Stop life-threatening external bleeding first, then open the airway and look at the chest. Expose it, look at both sides and the back, feel the chest wall and listen to both sides.
• Seal an open chest wound at once, then watch for tension and burp the seal if it develops.
• Give oxygen to a patient who is hypoxic or in distress, and assist ventilation if breathing is inadequate. Do not over-ventilate: positive-pressure breaths lower the return of blood to the heart and can make a pneumothorax worse.
• Recognize a tension pneumothorax early. Decompression is the paramedic's treatment under protocol; for an EMT, request ALS where it is available and quick, and do not delay transport waiting for it.
• Stabilize an impaled object in place. Do not remove it unless your protocol makes a specific exception.
• Let a patient with a chest injury and no spinal concern sit in the position that makes breathing easiest, unless they are in shock, where the positioning in the Perfusion and Shock guide applies. Where spinal motion restriction is needed, follow your protocol.
• Treat for shock and keep the patient warm. Any fluid and any blood pressure target are your protocol's.
• Transport without delay. For penetrating chest trauma in particular, time to surgery decides the outcome. Do procedures en route where you can and tell the receiving facility early what you suspect.
• Reassess often: breath sounds, work of breathing, ease of ventilation, oxygen saturation, EtCO2, mental status, skin, heart rate and blood pressure.

Calculate a shock index from heart rate and systolic pressure

Organize your handoff to the receiving team

The short version

• A simple pneumothorax is air in the chest; a tension pneumothorax is air under pressure that stops blood returning to the heart.
• Tension: absent breath sounds on one side, worsening distress, difficulty ventilating, and shock. Tracheal deviation is late; do not wait for it.
• Needle decompression is the field treatment for tension pneumothorax, within paramedic scope under protocol. It is not an EMT skill in the national scope model.
• Seal a sucking chest wound at once, prefer a vented seal where you have one, and burp the seal if tension develops.
• Flail chest is two or more adjacent ribs broken in two or more places, moving paradoxically. The lung contusion underneath is usually the bigger problem.
• Hemothorax brings shock with flat neck veins; tamponade brings shock with clear, equal breath sounds and often distended neck veins.
• Support breathing without over-ventilating, treat for shock, and get the patient to surgery quickly.