Kinetic Energy = 1/2 m v 2

Transcription

1 McHenry Western Lake County EMS System Optional CE for EMT-B, Paramedics and PHRN s Penetrating Injuries Optional # Penetrating trauma may present as some of the most graphic injury patterns you will encounter in the pre-hospital setting. Penetrating trauma is defined as an injury caused by an object breaking the skin and entering the body. In some cases, you may be looking at multiple wounds. The greater the speed of penetration, the more severe the injury tends to be. These injuries include gunshot wounds (GSWs) and stab wounds, as well as other types of impalements, and can range in severity from superficial punctures to penetration of major body systems. Consideration must be given to the anatomy under where the penetrating injury occurred. Kinetics of Penetrating Trauma The extent of an injury from a penetrating trauma is proportional to the amount of kinetic energy (KE) that is lost by a projectile. Kinetic energy of an object is equal to its mass times the square of its velocity, all divided by 2 (achieved by multiplying answer by 0.5). Kinetic Energy = 1/2 m v 2 m = mass of object and v = velocity of object It should be noted that doubling the mass only doubles the energy, whereas doubling the velocity quadruples the energy. Therefore a small object traveling at a high velocity (speed) will potentially produce more of a serious injury than a larger projectile at a lower velocity (speed). Categories of Injuries While these injuries can occur from a variety of sources, we will look at low, medium/high-energy injuries. Low Energy Inserted by hand Objects like knives and screw drivers, or non-ballistic weapons, used from a close range can cause low energy injuries. There are a few factors that need to be evaluated to determine if the injury is lifethreatening; the type of instrument used, injury location on the body, depth of penetration and number of wounds. If not still in the patient, it is important to identify what implement caused the puncture wound. A single stab wound to the center of the chest with a kitchen knife is a more critical life threat

2 than multiple stab wounds with a screw driver to a patient s forearm. While both are low energy penetrating traumatic injuries, we are able to identify a higher life threat with the kitchen knife because of its size and location of the injury. Medium and High Energy Propelled by force Bullets, arrows or other ballistic weapons typically cause medium- and high-energy, or high-velocity, injuries. Determinants such as the type of weapon, handgun vs. rifle, size of the projectile s caliber and distance at which the weapon was fired are all critical to determining the potential extent of the injuries. When looking at these wounds, try to envision the pathway the projectile took once it entered the patient. Smaller caliber bullets (i.e..22 calibers) tend to bounce around within the patient, increasing the extent of the injuries and body systems that are involved. Large caliber bullets, like a.45 caliber, are designed to continue straight and actually increase the pathway of injury until the projectile exits the body. This is due to a phenomenon known as cavitation, in which speed causes the projectile to generate pressure waves that result in damage distant from the projectile s path. Resultant tissue injury can be many times larger than the diameter of the projectile. This is why some wounds will look larger than others, on the same patient. It could signify an entry wound verses an exit wound. While it is not critical for EMS to immediately discern between medium- and high-velocity wounds, having this information will assist in the patient s care at the local trauma center. For pre-hospital providers, the focus remains on scene safety, the ABCs and rapid transport to an appropriate facility. Why is Cavitation so deadly? Aside from the ability to puncture human flesh upon contact, medium and high-velocity projectiles also can cause the cavitation injury. In short, this means that an object creates a concentrated spiral of pressure that pushes tissue away from the piercing. This phenomenon opens up a gap that is much larger than the circumference of the projectile itself. The displaced tissue eventually settles back into its original position, but not before significant damage has been done. Cavitation is also related directly to the ability of the body tissue to return to its original shape and position. Consider an injury to a hollow organ (stomach, intestines) compared to a solid organ (liver, brain). Permanent cavities are produced by penetrating injuries in which the force of the projectile exceeds the tensile strength of the tissue. Tissues with high water density (e.g. liver, spleen and muscle) or solid density (e.g. bone) are more prone to permanent cavitation.

3 Impaled Objects As we know, some objects enter the body and leave evidence sticking out of the skin. This could be a narrow diameter (arrow, tree branch) or a large diameter (telephone pole, guard rail) object. part of horse drawn carrage impaled into a motorcycle driver 1 The impact of the object (low velocity vs. medium/high velocity) is still a consideration. This will help to determine other injuries that may have been sustained. When an object is still impaled, the object may be occluding bleeding and should not be removed; stabilize the object in place. Some objects may need to be shortened so the patient can be put into a transport vehicle. When the object is being shortened, be aware of movement to the object and do not cause further injury to the patient. Trauma Assessment Review A pre-hospital approach to penetrating trauma is fairly straightforward. We look for entry and exit wounds and determine the anatomy between them. Though we don t make a determination between entry and exit wounds, we do need to account for all wounds on our patient. We can t have tunnel vision for the ones that look really bad.

4 The scene, however, may not be straightforward. As you approach, begin your scene size-up. If the scene seems unsafe, stage until it is safe. The crew can t help if they are injured or incapacitated. (History has shown that groups that have placed one bomb can place a second device.) Start with your general impression of the scene and your patients (if multiple). Evaluate the mechanism of injury (MOI), number of patients and any potential hazards. For a multiple patient incident; determine whether additional resources are needed. Do we need additional EMS units to treat/transport multiple patients, police to preserve evidence and secure the scene or fire crews to help with patient removal or stabilizing a hazard? Try to determine the patient s approximate age, potential MOI and obvious bleeding or injury even before talking to or touching them. Approach the patient in a way that won t cause them to quickly move there head, and in the process, exacerbate a spinal injury to the point of further injury, paralysis or even death. MOI may not immediately warrant spinal immobilization, but a penetrating injury may involve the vertebra and/or spinal column. The patient assessment will help to determine if immobilization is needed. If a backboard is used to move a patient, but is not used for spinal immobilization, be sure to document the difference. Driver called in his own accident. Is spine involved? Can he be put into spinal restriction? 2 Your trauma assessment should be done the same for every trauma patient. If you focus on the worst looking injury, a more critical injury can be missed. Anything that needs attention in regard to airway, breathing or circulation must be addressed as these problems are found. Excessive bleeding (exsanguination) may need to be corrected as airway and breathing are being assessed. LOC must be determined quickly to know if the patient is reliable to give information regarding spinal issues. Do not get tunnel vision focusing on a distracting wound; be careful not to overlook more subtle injuries. (An example is the patient who was beaten and then stabbed. You may immediately see the pool cue stuck in their forearm and classify it as non-life-threatening, but further assessment could reveal an abdominal injury sustained during the assault.) For an unconscious patient, you will need to do a Rapid Trauma Survey to determine all of their injuries. A Focused Exam is something that can be done if all indications (including patient reliability) point to the patient only having one injury. (An example would be a patient that has a nail imbedded in their foot because they stepped on it.) Try to determine a pathway between 2 opposing wounds. This will be a good indicator to what organ systems may be involved. With a penetrating trauma to the torso, there are a lot of different organs that may be affected. Remember the amount of movement the diaphragm has when a person takes a breath.

5 Depending on if they were inhaling or exhaling, will be were the abdominal organs are at the time of the injury. Bleeding control and maintaining blood pressures become critical. There is only a limited amount of care that can be done in the pre-hospital setting. Most of these injuries can only be stabilized by surgery. Solid organs will have more of a tendency for blood loss and they cannot be controlled in the pre-hospital setting. Direct pressure and hemostatic gauze (active shooter bag) can be used to control the exterior bleeding. With a penetrating wound to the torso, there is the possibility for a hemothorax developing. With the blood build up in the thoracic cavity, this will reduce the size of the lungs and potentially the size of the heart. In this case, permissive hypotension is allowed. Instead of maintaining a systolic blood pressure of 90 (Map 60-65), the systolic blood pressure should be maintained at 80 (Map 50-60). This is only if there is not a head injury. Perfusion to the brain takes priority. Upper torso injuries can also develop into a pneumothorax. If a lung has been punctured and we seal up the exterior wound, air can become trapped. This is why it is important to leave a way for the pressure to be relieved (or burped). That is why constant re-assessment of the patient is critical. Early recognition of trending changes will help determine injuries, care and the appropriate facility to transport the patient to (or divert to a closer facility). Trauma patients with multiple injuries, or are unconscious, should be completely undressed. This allows for you to thoroughly assess the patient and identify injuries. However, don t allow them to become hypothermic cover them with a blanket after their clothing has been removed. When possible, move the patient to a warmed ambulance (both geriatric and pediatric patients lose heat rapidly when exposed to the elements, particularly if they are wet). If the patient is a victim of violent crime, try not to cut through areas of the clothing that may have entrance/exit wounds or evidence stains. (Be aware of law enforcement s evidence collection needs.) After evaluating the ABCs, you must make a transport decision; a Level I or II trauma center. Keep scene times to 10 minutes or less. Remember, document any reasons why a scene time was longer than 10 minutes. Per SOP, any penetrating injury proximal to the knee or elbow should be transported to a Level I Trauma Center. This is regardless of if it is superficial or deep (a thin object like a car radio antenna will have a very small entry wound, but can go very deep). The transport time should be less than 30 minutes. If this can t be achieved, consider aeromedical transport. If neither of these can be achieved, then the patient can go to a Level II Trauma Center to be stabilized and then forwarded on to a Level I trauma Center. The important determination for any trauma patient assessment is to determine if we are treating and then transporting or transporting and treating simultaneously ( Stay and Play or Load and Go ). Remember, that this is a starting point. As the assessment continues, or reassessments are done, transport decisions are upgraded. (If we start to treat and the patient deteriorates, we can change our status to emergent and treat while transporting.) Remember to notify OLMC of the status change. Transport Decision Should all patients with penetrating trauma go directly to a Level I trauma center? It is important to know the trauma triage and transport criteria. A traumatic cardiac arrests should be transported to the closest emergency department. If a Level I trauma center is not within 30 minutes transport time, the patient should go to a Level II to be stabilized. The use of aeromedical transport can be used to keep the transport time under 30 minutes. Unstable patients should be transported to the closest emergency department/non- trauma center for stabilization. An unstable patient would be a patient whose airway cannot be established, or maintained, or is an impending traumatic cardiac arrest. Clinical indicators

6 combined with time limitations and provider experience will assist in the assessment of patient s that are not clearly defined. A good criterion is to error on the side of the patient. Penetrating traumas have significantly different survivability rates. All patients with penetrating trauma must be evaluated by a physician ideally, a trauma surgeon in a trauma center. Give advance notice to the receiving facility about the type of injury and the patient s condition. Relay any information regarding the type of implement or weapon used to the receiving facility. For example: 24-year-old male, stabbed multiple times in the torso and abdomen with what appears to be a knife or other sharp object. The length of the object may also be helpful. Keep it simple and to the point. If an object is still in the patient, give accurate information about the entry and exit points and if any special equipment may be needed to deal with the object (i.e. equipment that maybe be needed to further stabilize the object or special positioning that the patient may need to be put in). Conclusion It s critical for EMS providers to remember that penetrating trauma is a surgical injury with limited EMS interventions. Scene time and patient management play the largest roles in determining overall mortality. Understanding mechanisms of trauma and effectively dealing with traumatically injured patients are only some of the weapons in the EMS provider s arsenal. Remember: Penetrating injuries are more than skin deep, literally and figuratively. Final Note: The pictures used in this presentation are from victims that are alive and have been released from the hospital. When responding to these emergencies, safety of the crew and patient must be your first consideration. Safety must continuously be addressed, keeping in mind the type of incident and the potential for continued violence or additional traumatic injuries that could be directed toward the crew or other individuals on scene. References:

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8 McHenry Western Lake County EMS System Optional CE for EMT-B, Paramedics and PHRN s Penetrating Injuries Optional # NAME: DEPT: DATE: Provider Level: EMT-B Paramedic PHRN 1. What is the longest transport time that MWLC allows for transport to a Trauma I Center? a. 10 minutes b. 20 minutes c. 30 minutes d. 60 minutes (Golden Hour) 2. Explain cavitation. 3. A small caliber bullet will always produce less of an injury than a large caliber bullet. a. True b. False 4. Explain permissive hypotension and why it must be considered in a penetrating injury. 5. As we approach any scene, what is our primary concern? a. Airway b. Breathing c. Circulation d. Scene safety

9 6. Backboards are only to be used for spinal immobilization. a. True b. False 7. In a penetrating torso trauma, IV fluids should be given to maintain a SBP of. 8. What penetrating injury does not automatically go to a Level I trauma center? 9. When cutting off clothing of a penetrating trauma victim, what must you be aware of? a. Cut clothing from extremity toward torso b. Not cutting through evidence stains c. Tear through entry/exit holes, don t cut d. Both a and c The next few questions will be based on the following narrative: You are called to the scene of a 23 year old male who is the victim of domestic violence. Dispatch reports that shots were fired. Dispatch tells you they were informed by family members that the patient has a gunshot wound to his abdomen. Police on location advise that the scene is secure (the gun is secured and the shooter is in custody). 10. Since the scene is secure, what is the first priority on the assessment? a. Examine the gun used b. Look for entry and exit wounds c. Airway, Breathing and Circulation d. Find out the intent of the shooter did patient deserve it. While getting information for question #10, the patient doesn t answer questions appropriately. You understand that he is really dizzy. Skin is pale and cool. He shows you a wound on his back (that is about the size of nickel, just below the ribs on the right side) and a second wound (about the size of a quarter, in the Lower Right Quadrant of the abdomen) by his belt line. There is a large amount of blood on the floor with a large amount of blood still coming out of each of the injuries. 11. With the added information, what is next step in our evaluation? a. Determine the weapon used b. Bleeding control c. Exposing the patient to determine any other injuries d. Determine which wound is the entry wound and which is the exit wound

10 12. After you have completed Question #11, what is the next step? a. Determine the weapon used b. Bleeding control c. Exposing the patient to determine any other injuries d. Determine which wound is the entry wound and which is the exit wound. 13. If direct pressure is not working for bleeding control, what is an alternative that can be used? a. Tourniquet b. Hemostatic Gauze c. Hyfin Chest Seal d. Decompression Needle 14. How long should the scene time be with this patient? a. 5 minutes b. 10 minutes c. 30 minutes d. As long as is needed to complete all ALS procedures 15. Based on the information given so far, where is the best facility for this patient to be treated at? a. Closest Emergency Room (5 minutes ETA) b. Trauma II Center (10 minute ETA) c. Trauma I Center (33 minute ETA) d. Trauma I Center (25 minute ETA w/aeromedical transport) IF YOU ARE NOT A MEMBER OF THE MCHENRY WESTERN LAKE COUNTY EMS SYSTEM, PLEASE INCLUDE YOUR ADDRESS ON EACH OPTIONAL QUIZ TURNED INTO OUR OFFICE. WE WILL FORWARD TO YOUR HOME ADDRESS VERIFICATION OF YOUR CONTINUING EDUCATION HOURS. IF YOU ARE A MEMBER OF OUR EMS SYSTEM, YOUR CREDIT WILL BE ADDED TO YOUR IMAGE TREND RECORD. PLEASE REFER TO IMAGE TREND TO SEE YOUR LIST OF CONTINUING EDUCATION CREDITS. FAX YOUR COMPLETED QUIZ TO 815/ TO VERIFY IF YOUR FAX WAS RECEIVED, CONTACT CINDY TABERT AT 815/ THANK YOU.