Wednesday, February 23, 2011

Chest Trauma

Thankfully we don't see traumas too often at Shoreline Medical -- not near as often as big city trauma centers -- yet unfortunately we still get one from time to time, and we need to be prepared.

The major concern with chest traumas is, according to emedicine, "Blunt Chest Traumas," is "derangements in the flow of air, blood, or both in combination. Sepsis due to leakage of alimentary tract contents, as in esophageal perforations, also must be considered."

Chest Trauma Statistics

After head and spinal injury, chest trauma is the third most common cause of death from chest trauma. Likewise, chest trauma is responsible for 20-25% of all deaths in the U.S., which makes it the third most common cause of death. It is also a major contributing factor in 50% of all other deaths.

Of all chest traumas, 33% require hospitalization, and the mortality rate is about 10%. The most common cause (70-80%) of chest traumas is motor vehicle accidents.

Actually, according to emedicine, "Trauma is the leading cause of death, morbidity, hospitalization, and disability in Americans aged 1 year to the middle of the fifth decade of life. As such, it constitutes a major health care problem. According to the Centers for Disease Control and Prevention, approximately 118,000 accidental deaths occurred in the United States in 2005."

So these statistics are pretty significant, and a major reason why members of any emergency room -- including respiratory therapists -- need to be familiar with what we might have to treat in a trauma situation.

While broken bones are a serious concern, the most serious injury are chest injuries from blunt trauma, such as smacking into the steering column at high forces. Thankfully seat belt laws and air bags have significantly reduced morbidity and mortality, yet chest traumas continue to be a significant source of emergency room visits.

I'm not going to do this in any particular order, yet here I will briefly discuss all the complications we RTs will be concerned about and treating.

Brief History

As you can read here, "History of chest trauma," treatment for chest trauma was first described about 1600 BC in the Ancient Egyptian Edwin Smith Papyrus that was prepared by Inhotep in 3000 BC.

The article notes the first trauma centers were established during the Trojan War in the 1st century AD. "With the development of more effective management of injuries, the concept of a flying hospital or ambulance volante was developed by Napoleon's army surgeons when it became obvious that rapid transfer, together with early active management, produced the best results."

When De Chauliac, the "Father of Surgery" wrote his Chirurgia Magna in 1365, he was actually surprised to see so little written about trauma considering all the wars, the article notes, "Only Hippocrates had mentioned the association of chest wall injuries and haemoptysis as a result usually of rib fracture."

Likewise, the article notes:

"The importance of pneumothorax and haemothorax was realized in the 18th Century and many devices were devised to suck wounds out of the chest, sometimes using the mouth of a specialist to use his own inspiration to suck air or fluid from that of the injured. Later devices such as the Arel Syringe were developed which certainly improved the hygiene of this technique. Although trocars had been developed, caution in the use of these instruments was urged as early as the 18th Century and it was felt, even then, that the insertion of a finger in a carefully made incision was preferable to introducing a sharp pointed trocar which may damage the lung and other intra-thoracic structures."
Invention of the Arel Syringe allowed for more sterile technique, and it was soon "insertion of a finger in a carefully made incision was preferable to introducing a sharp pointed trocar which may damage the lung and other intra-thoracic structures."

Chest tubes (which we'll discuss in another post) and underwater seal systems owe their creation to English physicians during the Civil War. Giovanni Battista Morgagni (February 25, 1682 – December 6, 1771) was the first to describe lung contusions.

Chest trauma gained national recognition during WWI and WWII due to pulmonary contusions due to blasts. An increase in trauma from traffic accidents resulted in greater recognition of pulmonary contusions in the 1960s.

In fact it was chest trauma from steering column impaction that lead to modern seat belt laws, which has greatly diminished incidences of chest trauma.

Diagnosis of chest trauma: This can be relatively easy, as in most cases you'll know the cause of the injury, otherwise symptoms may entail any or all of the following:

  • Coughing up blood
  • Chest pain
  • Possible bruising (but not always) on the sternum
  • Cyanosis
  • Low SpO2

Further confirmation can be made by x-ray and ct scan.

Yet the initial workup of the patient should involve the ABCDEs of trauma, which include first making sure the patient has an Airway, second making sure the patient is Breathing, third making sure the patient has Circulating blood, making sure the patient is neurologically intact (Disability), and make sure the patient is completely undressed so you and the physician can fully assess the patient (Exposure).

To view a good slide that describes the ABCDEs of trauma click here.

Once that's all taken care of (or quite often while all that is going on), the following tests and procedures performed (according to emedicine):

1. Xray: Very important 1st line therapy for any blunt trauma to identify many conditions, such as broken ribs, pneumothorax, hemothorax, injuries to great vessels, damage to other organs or bones. It should be noted here that treatment of suspected pneumothoraxes and other such critical injuries should not have to wait for any test, including an x-ray, if they are life threatening.

2. CT Scan: Can be performed on the hemodynamically stable patient to more specifically diagnose a patient than an x-ray can.

3. 12 Lead EKG: Can help determine new cardiac abnormalities. Plus it can show other underlying problems. To learn more about what an EKG can be used to determine, click here.

4. Blood type and crossmatch: Should be done quickly if you suspect bleeding so you can give a transfusion as needed.

5. Cardiac enzymes: When a muscle is damaged it releases certain chemicals into the blood stream. CK greater than 200 indicates muscle damage somewhere in the body, CKMB indicates cardiac muscle damage, and troponin greater than 0.1 indicates heart muscle damage.

6. Coagulation profile: Especially important if the patient needs blood. It can tell a doctor how well a patient is clotting. PTT greater than 33 (greater than 60 is critical) and a PT greater than 12 (40 is critical) can be an indicator a patient is not clotting efficiently, or can be an indication of liver damage. An INR greater than 1.2 can indicate an acute bleed (greater than 6 is critical). A Fibrinolin level less than 160 is abnormal and may be indicative of an acute bleed (less than 70 is critical)

7. Complete blood count: Helps gage blood loss and gives a blood cell count.

8. Arterial blood gas: Can provide information about ventilation and oxygenation and acid base status, and therefore may act as a guide for need to intubate (To learn more about ABGs click here).

9 Lactate and Lactic Acid: These can indicate tissue death or damage. When these are out of range, this can indicate the patient is in big trouble. Critical levels are: LDH greater than 350, Lactic acid greater than 19.5, and Lactate greater than 4 can indicate tissue death.

10. Other: Aortogram, thoracic ultrasound, contrast esophogram, transesophogeal echocardiogram, transthoracic echocardiogram, flexible or rigid esophascopy and bronchoscopy are also tests commonly used to diagnose certain conditions in the chest trauma patient.

Now for the dreaded trauma related injuries.

(For more lab values click here)

Clinical history:

Along with your initial assessment, good questioning will help you get an idea of possible injuries. Often times this can be obtained by interviewing EMTs who were on the scene, family members, or other people who were a witness to the trauma event.

Important information to determine is:

  • The time of injury (how long ago did it occur)
  • Mechanism of injury (what exactly happened)
  • MVA velocity \
  • MVA deceleration
  • Evidence of associated injury to other systems (eg, loss of consciousness)
Now for the dreaded chest trauma injuries:

1. Rib Fractures: Pain from this can be excruciating, and this may cause the patient to take rapid and shallow breaths due to this pain. While rib fractures in and of themselves are not life threatening, there is the risk that they might puncture the lung and cause a pneumothorax (collapsed lung) or be pressed up against the lungs and cause a pulmonary contusion.

Your basic rib fracture is rarely of any consequence, and is generally treated with pain medicines. These patients must be encouraged to take an occasional deep breath regardless of the pain in order to prevent pneumonia, and should probably go home with incentive spirometers (You can read more about how to prevent pneumonia here).

2. Pulmonary contusions: This occurs in 30-75% of chest trauma incidences, according to Wikepedia, and is the most common type of potentially lethal chest trauma. It has a mortality rate of 14-40%, and are thought to be the cause of death of 25% of trauma deaths. The other 75% of trauma deaths are due to other complications (which we'll review below).

Pulmonary Contusions are the most common injury when it comes to chet trauma. When someone is hit hard on the chest wall (blunt trauma), this can result in damage to capillaries, which causes blood to accumulate in lung tissue, which can interfere with gas exchange, and leading to inadequate oxygen levels (hypoxemia and hypoxia), according to Wikepedia.

Contusions may resolve on their own, and in this case supportive measures -- such as supplemental oxygen -- may be all that's needed.

However, if breathing is further compromised, intubation and mechanical ventilation may be needed and fluid through an IV to ensure adequate blood volume (although carefully because we want to avoid fluid overload).

Pulnonary contusions may result in blood being shunted away from the lungs and areas of the lungs that are poorly ventilated, resulting in poor oxygenation (hypoxemia and hypoxia) and increasing carbon dioxide levels, impending acidosis (pH less than 7.35) and impending respiratory failure. . When this is severe enough, intubation and mechanical ventilation may be required.

Complications from pulmonary contusions can be ARDS and pneumonia. Complications from further blood loss may result in loss of blood volume and sepsis.

Flail chest: This occurs when several ribs (chest wall) break under extreme stress and the chest wall moves independently of the lungs. This occurs in about 30% of blunt chest trauma.

This increases work of breathing and is very painful. Half of people with this will die. It is often accompanied with pulmonary contusion, and it is believed the contusion and not the flail chest is That ultimately results in respiratory complications, according to Wikepedia.

Treatment includes quick care and thinking and, as needed...
  • Pain killers (try to avoid narcotics because they decrease respiratory drive)
    Positive pressure ventilation (low tidal volumes to avoid barotrauma)
  • Chest tubes if suspected pneumothorax (collapsed lung)
  • Position adjustment for patient comfort
In the case of Shoreline Medical, we usually stabilize these patients and ship them to the closest trauma center.

Pneumothorax: Another common injury, and this occurs when an object, such as a rib, bullet, knife, shrapnel, or other object pierces the lung, causing air to enter into the pleural cavity, or space between the lung and the chest wall.

This decreases forced residual capacity, or the amount of air that can enter the lungs, and decreases the lungs ability to expand, which results in decrease oxygen to the blood (hypoxemia). It can also be extremely painful and may result in extreme shortness of breath.

Diagnosis can be made by observation, such as unequal expansion of the chest wall on inspiration, and a deviated trachea, which usually moves toward the side of the lung with the pneumothorax. Diminished lung sounds and rubs are often heard over the collapsed lung upon auscultation.

Sometimes pneumothorax's resolve on their own, yet when more severe, or when they interfere with respirations, a chest tube is requires.

When severe, and in a small percentage of patients with a pneumothorax, this may lead to hypoxia, low blood pressure, and even death. And therefore, in some situations, a chest tube must be inserted based on initial assessment alone, before further diagnostic tests can be done.

Other diagnostic tests include chest x-ray and ct scan, and usually there is plenty of time to do one or both.

Insertion of a chest tube into the pleural space allows for air to escape, and the lungs to re-expand. I will describe chest tubes in further detail in a future post, yet if you want further reading now you can click here.

Tension Pneumothorax: This is a more serious complication, and this is where air continues to exit the lungs into the pleural space, building up pressure in that area. This pressure may squeeze the superior vena cava and can result in decreased blood return to the heart, circulatory compromise and shock, according to emedicine.

Hemothoraces: Blood in pleural spaces surrounding the lungs and/ or heart.

Hemopneumothoraces: Blood and air in the spaces surrounding the lungs and/ or heart

Other factors: Medpedia further notes that:
At the molecular level, animal experimentation supports a mediator-driven inflammatory process further leading to respiratory insult after chest trauma. Following blunt chest trauma, several blood-borne mediators are released, including interleukin-6, tumor necrosis factor, and prostanoids. These mediators are thought to induce secondary cardiopulmonary changes. Blunt trauma that causes significant cardiac injuries (eg, chamber rupture) or severe great vessel injuries (eg, thoracic aortic disruption) frequently results in death before

adequate treatment can be instituted. This is due to immediate and devastating exsanguination or loss of cardiac pump function. This causes hypovolemic or cardiogenic shock and death.

Medpedia also notes that sternal fractures are rarely of any consequence, except when they result in blunt cardiac injuries

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