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Published: 24.05.2023

Module 08: Respiration Assessment & Management in TFC

Tension pneumothorax remains a significant cause of preventable combat fatalities.

This module will focus on the management of respiration and chest trauma with techniques that are appropriate for the Tactical Field Care phase.

Respiration Assessment and Management in TFC


This module will focus on assessing and managing respiratory issues in Tactical Field Care, including the recognition and treatment of one of the leading preventable causes of death on the battlefield, tension pneumothorax.

As a combat medic/corpsman, the first medical provider to care for the casualty and initiate more advanced treatments, it is important that you understand the roles and responsibilities of the nonmedical personnel (All Service Members (ASM) and Combat Lifesaver (CLS)) who may be assessing casualties and providing care/assisting in treating respiratory problems in the prehospital environment.


This module has one terminal learning objective, supported by nine enabling learning objectives or ELOs.

The six cognitive ELOs include identifying respiratory distress, life-threatening chest injuries, open pneumothoraxes, the importance of vented chest seals, tension pneumothoraxes and signs of recurring or unsuccessful pneumothorax treatment.

The performance ELOs include demonstrating how to apply a chest seal and how to perform a needle decompression of the chest at the two primary sites.


Assessment and management of one of the most common causes of preventable death on the battlefield are discussed in this module. Respiratory assessment and management are done in the Tactical Field Care (TFC) phase of TCCC.

The ability to recognize the signs and symptoms of a respiratory emergency will enable you to apply life-saving techniques to treatable conditions. With the skills learned in this module, you will be able to identify and treat multiple life-threatening respiratory problems.


Respiration assessment and management is the “R” in the MARCH PAWS sequence.


Penetrating chest trauma results from an object entering through the skin and chest wall into the chest cavity. Examples include gunshot, stab, and fragment wounds.

Blunt chest trauma results from the impact of an object or an energy force on the chest wall such as in a motor vehicle crash, being struck in the chest with a bat, or a blast injury. In some instances, such as a blast from an improvised explosive device (IED), you may encounter a casualty with both blunt and penetrating chest trauma. Both blunt and penetrating chest trauma can be lethal.

Seeing a bruise or a gunshot wound on the chest can help you assess the casualty and the mechanism of injury. Getting under body armor and uniforms to assess a casualty is easier said than done. There will be times when you will have to rely on the mechanism of injury and the casualty's presentation to identify if they have a life-threatening injury.


As a medic you have been taught the basic signs and symptoms of respiratory distress, either too fast (tachypnea >20 breaths per minute) or too slow (bradypnea <8 breaths per minute). Other areas that you will have to assess for are cyanosis (seen in oxygen desaturation), tripod positioning, orthopnea (cannot breathe lying down), nasal flaring, two-three-word dyspnea, lightheadedness, diaphoresis, retractions, or any abnormal breath sounds.

Running with protective gear and equipment can cause tachycardia, tachypnea, and sweating (which mimics diaphoresis). While those signs and symptoms can mean the patient is critical, it could also mean that they are just exercising. Repeated assessments will help you to understand if your patient is in respiratory distress or if they will get better with rest.


We’ll talk in detail about the pulse oximeter's use as a monitoring tool in module 20, but a pulse ox level that is less than 90% can indicate a casualty is in respiratory distress.


Penetrating injuries to the chest wall can be difficult to find through the casualty’s clothes, protective gear and low-light situations. Expose and uncover any suspected anterior, posterior or axillary chest wounds. If multiple wounds are found, treat them in the order in which you found them.

Not all chest wounds are sucking chest wounds and some do not penetrate as deeply as the lung cavity. If you are not sure if the wound has penetrated the chest wall completely, treat the wound as though it were an open chest wound.


Signs and symptoms of an open pneumothorax include those seen in respiratory distress, in general, like difficulty breathing. But other signs or symptoms that should raise your level of suspicion of an open pneumothorax include seeing a punctured wound to the chest, seeing froth or bubbles around a chest wound, hearing a sucking or hissing sound as the casualty inhales, coughing up blood, or having blood-tinged sputum.


It is important to thoroughly inspect and palpate the entire chest wall (front, back, and sides) for any additional signs of chest injuries or wounds. Raking the chest and back requires you to drag your fingers along the chest and back to find any puncture in the skin.

If there are additional chest wounds, treat them the same way with vented chest seals.


Get to know the supplies within your Joint First Aid Kit (JFAK), CLS, and CMC bags. Vented chest seals are preferred.

Penetrating chest wounds (open or sucking chest wounds) are treated by applying a vented chest seal. Once a wound has been occluded with a vented chest seal, air can no longer enter the pleural space through the wound in the chest wall but can escape during exhalation. The injured lung will remain partially collapsed, but the mechanics of respiration will be better.

NOTE: If a vented chest seal is not available, use a non-vented chest seal.


The chest seal application will be reviewed during the video below, but a couple of points are worth mentioning in advance:

  • Place hand or back of hand over open chest wound to create a temporary seal.
  • When possible, use the chest seal from the casualty’s (JFAK).
  • If the area surrounding the wound has blood, sweat, or dirt, simply wipe it away with 4X4 gauze from the commercial chest seal package. This will help the adhesive action of the seal to perform better.
  • When casualty exhales, place adhesive side directly over open/sucking chest wound, pressing firmly to create a seal

Edges of the chest seal must extend 2 INCHES BEYOND the edges of the wound.

Continue to monitor the casualty after treatment with a vented chest seal. If the casualty condition worsens, a tension pneumothorax should be suspected. This will be discussed in detail later in this module but involves trapped air compressing the heart and great vessels and is significantly more dangerous than a standard open pneumothorax. If that happens, burping or removing, then replacing, the dressing may help – a procedure that will be explained in the video. Otherwise, a needle decompression of the chest may be needed.


Moving your casualty may cause the vented chest seal to become detached from the patient’s skin. Be very careful not to pull the adhesive portion of the vented chest seal off when you move the casualty onto a litter or even to sit the casualty up.

A hypoxic casualty may not be alert enough to follow commands. Place a conscious casualty in a sitting position or a position of comfort that best allows the casualty to breathe, if possible. Place an unconscious casualty with their injured side down in the recovery position.


This video will talk you through the steps of applying and managing a chest seal.



PDF Chest Seal Application Skills Card

Chest Seal Application

Read pdf

Consider the mechanism of injury, such as significant torso trauma or primary blast injury that could cause a tension pneumothorax.

Below, the left picture shows a penetrating chest wall injury, and the picture on the right shows a collapsed lung – both could be caused by primary blast injuries or secondary and tertiary effects causing significant torso trauma.

What’s important is being able to identify the signs and symptoms of a tension pneumothorax and treat it aggressively. When in doubt, place a vented chest seal on the wound. If it’s an open chest wound (picture to the left) or a closed chest wound (picture to the right).

Imagine a balloon inside the chest wall that gets bigger with every breath. Eventually, that balloon gets so big that the lungs, heart, and trachea are compressed to the point that the intact lung cannot inflate properly and the heart will not be able to pump.

Positive air pressure enters from the wound (like a one-way valve) and into the pleural space that consists of negative pressure, between the lung and the chest wall. Pressure then builds up on the injured side, which eventually starts to compress both lungs and the heart.


Remember that a pneumothorax normally is not a life-threatening injury, but a tension pneumothorax is life-threatening. As intrathoracic pressure increases, casualties develop hypotension, jugular vein distention (JVD), and tracheal deviation. The affected hemithorax is hyper-resonant to percussion and often feels tense, mildly distended, and hard to compress on palpation. Some people compare the chest to the feeling of pressing a fully inflated football.

Signs of tension pneumothorax include early and late signs. The early signs and symptoms to look for relate to significant torso trauma or primary blast injury and commonly include:

Early Signs

  • Severe or progressive respiratory distress
  • Severe or progressive tachypnea – abnormally rapid breathing
  • Absent or markedly decreased breath sounds on one side of the chest
  • Hemoglobin oxygen saturation < 90% on pulse oximetry
  • Shock – If not treated promptly, tension pneumothorax may progress from respiratory distress to shock and traumatic cardiac arrest.
  • Traumatic cardiac arrest without obviously fatal wounds

Late Signs:

  • Tracheal deviation
  • Jugular vein distention
  • Subcutaneous emphysema
  • Shift of the mediastinal contents away from the side of the tension pneumothorax

The late signs may not be displayed or may be displayed only when the casualty’s condition has worsened. Late signs that indicate the progression of tension pneumothorax include JVD from the mechanical obstruction of blood flow returning to the heart; tracheal deviation (a shift of the windpipe to the right or left); and tachycardia, as the body attempts to push more blood to the lungs to be oxygenated.


The incidence of preventable death resulting from tension pneumothorax has been reduced in the recent Middle Eastern conflicts. One reason for the decrease is that U.S. combatants now use personal protective equipment that provides significant protection for the chest and back, though it should be noted that chest wounds may still result from bullets or shrapnel impacting near the edge of the body armor and traveling into the chest.

Despite the use of modern body armor, tension pneumothorax remains one of the leading causes of death on the battlefield and can be managed in the field. Like hemorrhage, tension pneumothorax is treatable.

These signs may be difficult to assess in a combat situation. You must be alert to the possibility of tension pneumothorax whenever a casualty has penetrating or other chest wounds. Therefore, the sole criterion for suspecting a tension pneumothorax is significant torso trauma or primary blast injury and one or more of the following:

  • Severe or progressive respiratory distress
  • Severe or progressive tachypnea
  • Absent or markedly decreased breath sounds on one side of the chest
  • Hemoglobin oxygen saturation < 90% on pulse oximetry
  • Shock
  • Traumatic cardiac arrest without obviously fatal wounds

It is important to evaluate casualties during TFC for early and late signs of tension pneumothorax. Left untreated, tension pneumothorax can cause severe respiratory distress, shock, and death. The treatment for a tension pneumothorax is to let the air trapped under pressure escape by performing a needle decompression of the chest.


One site that can be used for needle decompression of the chest, or NDC, is the 2nd intercostal space at the midclavicular line (or MCL). You should evaluate the clavicle and draw an imaginary line at the center of the clavicle.

NEVER attempt an NDC medial to the midclavicular line or medial to the nipple. You increase the chances of hitting vascular structures in the mediastinum by doing this.

You should also never point the needle towards the heart; insert it perpendicularly to the chest wall. Additionally, you should always avoid insertion directly under a rib. The neurovascular bundle runs along the bottom of the ribs, so the optimal site is just over the top of the 3rd rib.

Another site is the 5th intercostal space at the anterior axillary line (AAL). The 5th intercostal space is located at the level of the nipple in young, fit males. The nipple level is variable in females – but you can lift the breast and use the level of the infra-mammary fold. The AAL is located at approximately the lateral aspect of the pectoralis major muscle, also more easily located in males.

Either site can be used for NDC. There is no evidence that shows one site is better than the other.


If the casualty is unconscious, place in the supine or recovery position with the injured side down. However, it is important not to dislodge or cover the opening of the NDC catheter when positioning the casualty.

If conscious, allow the casualty to adopt the sitting position if that makes breathing more comfortable or help keep the airway clear as a result of maxillofacial trauma.


As mentioned previously, if a vented chest seal is in place and there is evidence to suggest a tension pneumothorax has recurred, you can burp the chest seal; however, consider an NDC if symptoms do not improve.

If an NDC shows improvement in the casualty status but then the casualty shows signs of a tension pneumothorax again, then perform a second NDC near the same site. If there is no improvement, proceed to the assessment of circulation.

In cases where the initial NDC does not improve the casualty status, try the alternate site. If again there is no casualty improvement, then move on to the “C” in MARCH.


This video will demonstrate the steps of performing a needle decompression of the chest.



PDF Needle Decompression of the Chest (NDC) Skills Card

Needle Decompression of the Chest (NDC)

Read pdf

To help recap some of the main points of this module, here’s a short highlight video.


One of the most common causes of preventable death on the battlefield is tension pneumothorax.

The faster that you can identify and treat the casualty with a tension pneumothorax, the higher the chances are of survival.

When you first see an open pneumothorax, place a gloved hand over the wound, apply the vented chest seal and ensure that the wound is completely covered, and all sides are taped down. Remember to look for another wound and place a vented seal over every wound to “close” the respiratory system.

Look for signs or symptoms of a tension pneumothorax. You can attempt to burp the wound by lifting a side of the vented chest seal. If that does not work, then perform an NDC. There is no data to say that either NDC site is better, so you can choose based on the situation as to which site to use.

Reassessing your casualty after treatment will be vital in the survivability of the casualty that has a pneumothorax.

If your casualty has a major chest injury, they need to be evaluated by an advanced medical professional at a higher echelon of care.


To close out this module, check your learning with the questions below (answers under the image).


Check on learning


What is tension pneumothorax?

As a tension pneumothorax develops, air enters the chest cavity through the wound with every inspiration, but doesn’t leave with expiration and is trapped, so every breath adds more air to the air space inside the rib cage and outside the lung, and the pressure inside the chest builds up and causes the lung to collapse. Injured lung tissue acts as a one-way valve, trapping more and more air between the lung and the chest wall. Pressure builds up and compresses both lungs and the heart.

How should you treat an open chest wound?

Treat open chest wounds by applying a vented chest seal completely over the wound during expiration.

What should you do if you suspect a casualty has a tension pneumothorax?

If a chest seal is in place, burp the seal. If there is no improvement after burping the seal perform a needle decompression of the chest.



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