Hidden Hemorrhage

This article appeared in the EMS World special supplement Combating the Hidden Dangers of Shock in Trauma, developed by Cambridge Consulting Group and sponsored by North American Rescue, LifeFlow by 410 Medical, and QinFlow. Download the supplement here. 

The No. 1 cause of preventable death for trauma patients is uncontrolled bleeding, particularly in the first 24 hours.¹ Much attention over the last few years has been given to the use of tourniquets and wound packing for rapid control of obvious external bleeding, and this has met with much success.²

Internal hemorrhage, such as that found with injuries involving the chest, abdomen, and pelvis, presents challenges in prehospital assessment and management that dressings and tourniquets won’t solve.

In addition, fractures of the long bones of the extremities can result in extensive bleeding into the surrounding soft tissues. Survival of these patients depends on early recognition of the potential for internal hemorrhage and quick decisions to give the patient their best chance.

Internal hemorrhage is much more elusive and difficult to identify, especially with the limitations in the out-of-hospital evaluation process. Many of the tools used to identify internal hemorrhage in the hospital, such as ultrasound and CT scans, are generally not available in the prehospital setting.

In the prehospital setting a high index of suspicion and careful assessment are required. Internal bleeding may result in visible clues, such as swelling or discoloration of the skin as hematoma or ecchymosis (bruising) develops, or the bleeding may be completely hidden from view. 

Rebound tenderness, although often a feature of acute appendicitis and other acute intra-abdominal emergencies, can occur due to trauma and bleeding from the abdominal organs. Rebound tenderness is pain expressed by a patient upon the quick removal of pressure from the abdominal wall rather than the direct application of pressure to the abdomen.

The physical exam may reveal marks from a lap belt, ecchymosis, abdominal distention, absent bowel sounds, and tenderness to palpation. If peritonitis is present, abdominal rigidity, guarding, and rebound tenderness may be also.

Hemorrhagic shock is a clinical condition in which the supply of oxygen to the organs and tissues of the body is compromised as a result of blood loss. As a result of insufficient oxygen, the cells can no longer manufacture adequate amounts of energy to supply the needs of the cells and organs. If this lack of energy persists long enough, the cells and organs will cease to function and fail.^3,4

Blood Volume & Hemorrhage

The amount of blood the average person has can be estimated based on body weight.⁵ 

• Adult: Approximately 65 ml (females) to 70 ml (males) per kg of body weight; for example, in a patient with a body weight of 70 kg, this equates to approximately 4.5 L in women and 5.25 L for men. 
• Child: approximately 70–75 ml per kg of body weight;  
• Infant: Approximately 75–80 ml per kg of body weight.

As blood is lost a predictable series of events often occurs.⁶

• Blood is shunted away from the skin and periphery to preserve blood flow to vital organs. As a result the patient begins to look pale.
• With approximately 15% blood volume loss, compensatory mechanisms will maintain blood pressure; however, heart rate typically is increased.
• With 20%–40% blood loss, blood pressure will start to decrease, the patient’s skin will appear pale, cool, and diaphoretic, and the patient may feel anxious or confused.
• With more than 40% blood loss, the patient’s pulses will feel weak, their respiratory rate will increase, and they will be confused or unconscious.³

Thorax Injuries

Injuries to the thorax can result in life‑threatening hemorrhage. Pneumothoraces and other penetrating chest wounds from isolated or multiple rib fractures often have associated hemothoraces. 

A broken clavicle or rib can result in the loss of 100–150 ml of blood per rib, and bleeding can be much more significant if the broken rib lacerates a blood vessel such as an intercostal artery. 

A hemothorax can result in more than a liter of blood collecting in the chest cavity. Patients who have significant chest deformities will often be hemodynamically unstable because of poor lung mechanics and potentially life-threatening bleeding into the thoracic cavity. 

Other, more subtle findings of simple rib fractures or a small flail segment may go unnoticed if the patient is breathing at a shallow depth or has other injuries. These injuries, if missed on the primary assessment, may be uncovered in the secondary assessment or may go undetected by even the trauma center team until an x-ray or CT scan is performed.

Abdominal Trauma

Abdominal trauma can cause significant internal hemorrhage. In fact, the abdomen has the potential to contain the patient’s entire blood volume. A rapidly distending abdomen after trauma is an obvious indication of bleeding into the peritoneal cavity, but in many cases the signs of injury are more subtle. 

For instance, physical evidence of low anterior or lateral rib fractures suggests the possibility of hepatic or splenic injury, depending on the side. Ecchymosis over the anterior inferior abdominal wall is associated with intestinal injury. In motor vehicle crashes this injury is often called the “seat belt sign.”

Pelvic Injuries

Pelvic fractures can cause life-threatening hemorrhage, and significant bleeding should be assumed in any patient who appears to have one. Bleeding from pelvic fractures can be into the abdominal cavity or into the soft tissues of the pelvis, lower abdominal wall, back, and perineum. A pelvic fracture can result in the complete loss of a patient’s blood volume.

Large Bone Fractures

Large bones such as the femur, pelvis, and humerus have an extensive blood supply and can bleed a great deal when fractured, even without lacerating adjacent blood vessels.^7,8 The potential for vascular injuries along with these fractures adds to the potential for considerable blood loss. 

A humerus fracture, for instance, can release up to 1.5 L of blood into the upper arm. Other examples of bleeding from fractures include:

• Femur, 1–2 L
• Tibia, 500 ml–1 L
• Hip, 500 ml–2.5 L

Physiologic Compensation

Recognizing patients who have internal bleeding is further complicated by the body’s compensatory mechanisms. These may initially mask the seriousness of the injury. 

During compensation the heart is stimulated to increase cardiac output by increasing the strength and rate of contractions. Additionally, the blood vessels constrict, which reduces the overall size of the vascular system. This allows the body to maintain normal or near-normal blood pressure for a time, but if the bleeding isn’t controlled or blood volume replaced, the compensatory mechanism eventually will fail, and blood pressure will drop. The compensating patient is already in shock but will crash if the crisis isn’t solved.

To quickly identify these patients and give them their best chance for optimal outcomes, maintain a high index of suspicion for serious injury even if the blood pressure is within normal limits. Although a systolic blood pressure (SBP) less than 90 mmHg has traditionally been considered the threshold for shock, trauma patients with an SBP less than 110 mmHg should be considered at increased risk of serious injury and hemorrhage.^4,9,10 In fact, hypotension is a late sign of shock.¹¹ The potential for life-threatening hemorrhage after trauma must be recognized before hypotension develops.

High Index of Suspicion 

Speed is of the essence in management of the critical trauma patient. As time is muscle for cardiac patients, when dealing with trauma victims we can say time is red blood cells. Every minute that passes before bleeding is controlled allows the loss of more.

However, don’t overlook the possibility of a hidden yet serious condition in the patient who appears to have only a simple minor injury. Repeat physical assessments and continuous vital signs monitoring will help detect subtle changes over time.

To assess a patient rapidly and accurately requires honing the skills of a trained observer and using good clinical judgment. While instruments such as the stethoscope, sphygmomanometer, ECG monitor, and pulse oximeter are valuable adjuncts to the physical examination, success as a prehospital provider depends upon the ability to identify and collect comprehensive and accurate data about the patient’s condition. 
If assessment skills are sharp, then considering the possible underlying causes for the patient’s problem and any life-threatening causes can be accomplished quickly and effectively.

Mechanism of Injury

Assessment of the scene and mechanism of injury (MOI) will help determine the amount and type of energy the patient has absorbed. Understanding the forces at work in the event will help you determine the amount of energy involved and potential for internal injuries and bleeding. Recognition of the potential injuries associated with a particular mechanism of injury will enhance the level of suspicion that such injuries may be present and help focus the physical examination.

Internal bleeding can be caused by both penetrating and blunt trauma. In both cases there may be little or no obvious external bleeding. In penetrating injuries always assume the penetrating object (knife, bullet, etc.) has damaged an internal organ, resulting in internal bleeding.

In blunt trauma there are several patterns that can cause internal injuries. Compression injuries can cause rupture of internal structures. Shearing forces can cause tears in blood vessels where they are attached to internal organs or other structures. Damage to organs such as the liver can also occur where they are supported and restrained by ligaments, leading to hemorrhage.

Assessment of the Trauma Patient

Effective management of the injured patient depends upon a rapid, organized assessment. Time is critical, and every minute that passes for a patient with uncontrolled bleeding in the chest or abdomen increases the likelihood of a poor outcome. The only place this type of hemorrhage can be controlled is the operating room.

The importance of quickly recognizing and transporting critically injured patients to designated trauma centers cannot be overstated. Data show patients who are transported to appropriate trauma facilities have greater survival from their injuries compared to those transported to closer nontrauma facilities.^12,13

The American College of Surgeons Committee on Trauma (ACS COT) recommends patients with the following injuries should direct an immediate transport decision to the highest-level trauma center within the geographical region:¹⁴

• Penetrating injuries to head, neck, torso, or extremities proximal to elbows and knees
• Flail chest
• 2+ proximal long bone fractures
• Pelvic fractures
• Open or depressed skull fractures
• Spinal injury with neurological deficit
• Amputation proximal to wrist or ankle
• Crushed, degloved, mangled, or pulseless extremity
• Active bleeding requiring a tourniquet or wound packing with continuous pressure.

The ACS COT has identified a series of physiologic parameters that suggest the need for urgent intervention and transport to a trauma center.¹⁴ They include:

• Unable to follow commands (motor GCS ≤6)
• Respiratory rate ≤10 or ≥29 breaths per minute
• Respiratory distress or need for respiratory support
• Room-air pulse oximetry ≤90%
• Systolic blood pressure (SBP):
  • Age 0–9 years, ≤70 mmHg + (2 times age in years)
  • Age 10–64 years, ≤90 mmHg or heart rate ≥SBP
  • Age ≥ 65 years, ≤110 mmHg or heart rate ≥SBP.

The Shock Index

A useful prehospital tool for evaluating the potential of shock in a trauma patient is the shock index (SI).^15–19 The SI value is obtained by dividing the patient’s heart rate by their systolic blood pressure (SI=HR/SBP). For instance, if the heart rate is 100 beats per minute and the SBP is 80 mmHg (ie, 100/80), the shock index value would be 1.25, which is considered moderate shock.²⁰ The complete range of values is shown below.

• ≤0.6, no shock
• ≥0.6 to ≤1.0, mild shock
• ≥1.0 to ≤1.4, moderate shock
• ≥1.4, severe shock.

Mechanism of Injury

During the scene size-up, the severity of the mechanism of injury should also be evaluated. The ACS COT has identified the following injury mechanisms as potentially significant requiring transport to a trauma center (although not necessarily the highest-level trauma center):¹⁴

• High-risk auto crash:
  • Partial or complete ejection from vehicle
  • Significant intrusion (including the roof):
    • ≥12 inches of occupant site or
    • ≥18 inches any site or
    • Need for extrication
  • Death in passenger compartment
  • Child (0–9 years) unrestrained or in unsecured child safety seat
  • Vehicle telemetry data consistent with major vehicle damage
• Rider separated from transport vehicle with significant impact 
• Pedestrian/bicycle rider thrown, run over, or with significant impact
• Fall from height ≥10 feet (all ages).

An EMS provider should use their judgment, considering risk factors that include:¹⁴

• Low-level falls in young children 
• (≤5 years) or older adults (≥65 years) with significant head impact
• Anticoagulant use
• Suspicion of child abuse
• Special, high-resource health 
• care needs
• Pregnancy ≥20 weeks
• Burns in conjunction with trauma
• Children should be triaged preferentially to pediatric-capable centers.

If the MOI is major, quickly assess the critical areas of the body to locate potential life-threatening injury sites. Your assessment begins at the head and systematically covers the central trunk, followed by the extremities and finally the back. This assessment isn’t designed to find every single injury and determine every detail; rather, it determines major injury patterns using the combination of inspection, palpation, and auscultation. 

Pay close attention to the head, trunk, pelvis, and hips, as fractures and injuries to these locations often indicate life-threatening problems are present.

Transport Decisions and Continuous Monitoring

Immediate transport to a trauma center or suitable hospital is one of the main goals of the out-of-hospital management of trauma patients with significant injury.3 Decide when and where to transport the patient as soon as possible.

The emphasis on timely transport and brief scene times is because expeditious definitive treatment is a crucial parameter in the ultimate morbidity and mortality of the trauma patient, and that definitive treatment (usually operative control of bleeding) can only be provided at an appropriate hospital. Every responder must be knowledgeable regarding the hospital capabilities and resources in their response area. 

Responding EMS personnel must ask themselves the following questions:

• How quickly should the patient be extricated?
• How will the patient be extricated from the scene?
• How quickly should the patient be transported to the facility?
• To which facility should the patient be transported?

As expected, most of these decisions can be based upon the findings of the primary assessment. The more serious the patient presentation, the greater the need for immediate transport.

Minor Trauma Mechanisms

A minor trauma mechanism generally doesn’t cause enough force to seriously injure the patient. For example, a helmeted boy falling off his bicycle may not experience anything more serious than cuts and bruises and the occasional fracture of a long bone or wrist.

However, you must carefully and fully consider the mechanism of injury before deciding it’s indeed minor in nature. If that same boy isn’t wearing a helmet and strikes his head against the road, he may experience a life-threatening brain injury.

It’s also possible a patient’s past medical history or medications can complicate a seemingly minor traumatic event. For example, if a patient is taking an anticoagulant for a heart condition, even the most minor trauma could cause bleeding that can’t easily be stopped. 

This is especially true in elderly patients who have an impaired ability to compensate for blood loss, low blood pressure, or exposure to heat and cold. The elderly, as well as patients with debilitating bone illnesses, may break major bones with only minor force. Consider all aspects of the MOI before deciding its severity.

Once the MOI is determined to be minor and the primary assessment is complete, perform a physical examination that focuses on the injury site, looking for any open wounds, deformity, swelling, pain, or tenderness. If an extremity is injured, carefully confirm that circulation distal to the injury site isn’t compromised and motor and sensory response is intact.

After the focused physical examination, obtain a full set of vital signs and SAMPLE medical history. If time permits or the provider chooses, a complete head-to-toe physical exam may also be performed.
Referred pain can be difficult to assess. Maintain a high index of suspicion and look for life threats first. Always suspect the worst-case scenario until a serious injury has been ruled out.

Ongoing Assessment

As the call progresses, reassess the patient’s condition continuously. Conduct repeated primary assessments in patients who are borderline in terms of airway, breathing, or circulatory status. 

Reassess vital signs every few minutes and after each intervention. The more critical the patient’s condition, the more frequent the need to reassess.

Summary

Rule No. 1 of renowned trauma physician Dr. Norman McSwain’s rules of patient care is, “Death is your adversary and competitor—fight to win!”²¹ To prevent death in patients with hidden bleeding requires a comprehensive fund of knowledge, recognition of the mechanism of injury and potentially associated injuries, strong assessment skills, knowledge of available resources, and a commitment to close and continuous observation to give the patient their best chance.

References

1. Cherkas D. Traumatic hemorrhagic shock: advances in fluid management. Emerg Med Pract. 2011; 13(11): 1–20. 

2. Teixeira PG, Brown CV, Emigh B, et al. Civilian prehospital tourniquet use is associated with improved survival in patients with peripheral vascular injury. J Am Coll Surg. 2018; 226(5): 769–76.

3. Cannon JW. Hemorrhagic shock. N Engl J Med. 2018; 378(4): 370–9.

4. Edelman DA, White MT, Tyburski JG, et al. Post-traumatic hypotension: Should systolic blood pressure of 90-109 mmHg be included? Shock. 2007; 27(2): 134–8.

5. Gutierrez G, Reines HD, Wulf-Gutierrez ME. Clinical review: Hemorrhagic shock. Crit Care. 2004; 8(5): 373–81.

6. Cloonan CC. Immediate Care of the Wounded. Brookside Associates; 2007.

7. Hooper N, Armstrong TJ. Hemorrhagic shock. In: StatPearls. StatPearls Publishing; 2021.

8. Lee C. Porter KM. Prehospital management of lower limb fractures. Emerg Med J. 2005; 22(9): 660–3.

9. Bruns B, Gentilello L, Elliott A, et al. Prehospital hypotension redefined. J Trauma. 2008; 65(6): 1217–21.

10. Eastridge BJ, Salinas J, McManus JG, et al. Hypotension begins at 110 mm Hg: Redefining “hypotension” with data. J Trauma. 2007: 63(2): 291–9.

11. Parks JK, Elliott AC, Gentilello LM, et al. Systemic hypotension is a late marker of shock after trauma: A validation study of Advanced Trauma Life Support principles in a large national sample. Amer J Surg. 2006; 192(6): 727–31.

12. MacKenzie EJ, Rivara FP, Jurkovich GJ, et al. A national evaluation of the effect of trauma-center care on mortality. N Engl J Med. 2006; 354(4): 366–78.

13. West JG, Trunkey DD, Lim RC. Systems of trauma care: A study of two counties. Arch Surg. 1979; 114(4): 455–60. 

14. American College of Surgeons Committee on Trauma. 2021 Field Triage Guidelines.

15. Pottecher J, Ageron FX, Fauché C, et al. Prehospital shock index and pulse pressure/heart rate ratio to predict massive transfusion after severe trauma: Retrospective analysis of a large regional trauma database. J Trauma. 2016; 81(4): 713–22.

16. Zhu CS, Braverman M, Goddard S, et al. Prehospital shock index and systolic blood pressure are highly specific for pediatric massive transfusion. J Trauma. 2021; 91(4): 579–83.

17. Vandromme MJ, Griffin RL, Kerby JD, et al. Identifying risk for massive transfusion in the relatively normotensive patient: Utility of the prehospital shock index. J Trauma. 2011; 70(2): 384–90.

18. Jehan F, Con J, McIntyre M, et al. Pre-hospital shock index correlates with transfusion, resource utilization and mortality; The role of patient first vitals. Am J Surg. 2019; 218(6): 1169–74.

19. Kheirbek T, Martin TJ, Cao J, et al. Prehospital shock index outperforms hypotension alone in predicting significant injury in trauma patients. Trauma Surg Acute Care Open. 2021; 6(1): e000712.

20. Mutschler M, Nienaber U, Münzberg M, et al. The Shock Index revisited—a fast guide to transfusion requirement? A retrospective analysis on 21,853 patients derived from the TraumaRegister DGU. Crit Care. 2013; 17(4): R172. 

21. McSwain NE. McSwain’s rules of patient care. Trauma Pro. Accessed April 5, 2000. www.thetraumapro.com/2020/06/19/the-laws-of-trauma/

Sidebar: Dedicated to Norman E. McSwain, MD, FACS

This article is dedicated to the lifetime contributions of Norman E. McSwain, MD, FACS (1937–2015)

Norman E. McSwain, MD, passed away on July 28, 2015, in his beloved city of New Orleans. Internationally renowned and respected for his pioneering work in trauma care, McSwain founded NAEMT’s Prehospital Trauma Life Support (PHTLS) program 30 years ago and is recognized as the father of NAEMT education.

In addition to his prestigious career as a trauma surgeon, McSwain was a certified paramedic. He worked tirelessly throughout his career to ensure EMS practitioners in both the civilian and military sectors received the highest-quality education.

McSwain understood the important role of paramedicine in improving patient survivability in trauma and made it part of his life’s mission to provide all EMS practitioners with the knowledge and skills needed to make good decisions in the field. 

McSwain, who started the paramedic system in Kansas City, left Kansas in 1977 to return to New Orleans and help establish a paramedic system in the “Big Easy,” one of the last major cities in the U.S. without one.1,2 At the time ambulance service was delivered by the New Orleans Police Department, but McSwain told Paramedics International magazine in 1979 that within 5 years he wanted to establish a New Orleans EMS/ALS system that would be the best in the nation. He kept his word, developing an EMS system in New Orleans that has been nationally recognized for its strong medical direction, advanced trauma and medical care, and innovations in EMS.^1,2

A case report in this supplement focuses on the latest innovation at New Orleans EMS, the administration of blood to trauma victims. The New Orleans EMS system calls its program a trauma blood delivery system, not just a whole blood delivery system, because in addition to whole blood, it can also administer packed red blood cells (PRBCs), leukocyte-reduced red blood cells (LRBCs), or plasma, based on the availability of supply. It’s an innovation that would make Dr. McSwain proud.

• Read the entire 1979 Paramedics International interview at https://images.jems.com/wp-content/uploads/2015/07/paramedics-international-summer-1979-McSwain.pdf. 
• Read McSwain’s Rules of Patient Care at www.the traumapro.com/2020/06/19/the-laws-of-trauma/.

References

1.  Slakey DP, Lobrano V. A tribute to Dr. Norman E. McSwain. National Association of EMTs (NAEMT). Accessed April 7, 2022. www.naemt.org/education/phtls/tribute-to-dr-mcswain 

2. An Interview with Dr. Normal McSwain. (Summer 1979.) Paramedics International: A Journal of Pre-Hospital Care. Accessed April 7, 2022. https://images.jems.com/wp-content/uploads/2015/07/paramedics-internation al-summer-1979-McSwain.pdf 

Will Chapleau, EMT-P, RN, TNS, is the former fire chief of the Chicago Heights Fire Department in Illinois and a member of the International Prehospital Medicine Institute. He has been a paramedic for 41 years, a trauma nurse specialist for 30 years, and an EMS educator for more than 20 years.

Greg Chapman, BS, RRT, CCEMT-P, is the former director of the Center for Prehospital Medicine at the Carolinas Medical Center in Charlotte, North Carolina. He is a paramedic, respiratory therapist, and educator who has been involved in EMS since 1975.

Michael Hunter, NRP, TP-C, is deputy chief of EMS for the Worcester EMS Department in Worcester, Massachusetts.

Steven M. Mercer, MEd, EMT-P, is the former EMS unit lead for the Iowa Department of Public Health.

Peter T. Pons, MD, FACEP, is an emergency physician in Denver and has been actively involved with prehospital care and disaster preparedness for more than 30 years.

Lance Stuke, MD, FACS, is a trauma surgeon at the Spirit of Charity Trauma Center in New Orleans and a former paramedic.