Abdominal Injuries

Abdominal & Genitourinary Injuries

Abdominal and Genitourinary Trauma

Abdominal injuries can be challenging to assess and manage because serious internal damage may exist even when few external findings are present. Definitive treatment for significant abdominal trauma usually occurs at the hospital rather than in the prehospital setting.

The abdominal cavity contains many vital organs and major blood vessels, making trauma to this region potentially life-threatening. Injury may result in internal hemorrhage, organ damage, infection, or shock. Genitourinary structures may also be affected during significant abdominal or pelvic trauma.

Anatomy and Physiology

For assessment purposes, the abdomen is commonly divided into four quadrants. Knowing which organs normally lie in each region can help EMS providers identify structures that may have been injured.

Right Upper Quadrant (RUQ)

The right upper portion of the abdomen contains structures such as:

Because the liver is highly vascular, significant trauma to the RUQ can result in substantial internal bleeding.

Left Upper Quadrant (LUQ)

The left upper portion of the abdomen includes:

The spleen contains a large blood supply, so injury to this organ may cause serious internal hemorrhage.

Right Lower Quadrant (RLQ)

The right lower portion of the abdomen contains:

Injury to this area may involve intestinal, urinary, or reproductive structures.

Left Lower Quadrant (LLQ)

The left lower portion of the abdomen contains:

Trauma in this region may therefore affect gastrointestinal, urinary, or reproductive organs.

Important Abdominal Structures

Several major organs may be involved in abdominal trauma, including the:

Because many of these organs are located deep within the abdominal cavity, substantial injury and bleeding can occur without an obvious external wound. EMS assessment should therefore consider the mechanism of injury, abdominal pain or tenderness, distention, bruising, guarding, vital-sign changes, and signs of shock.

Abdominal and Pelvic Anatomy

Important Abdominal Spaces

Understanding the spaces within the abdomen helps identify which organs may be injured during trauma and where internal bleeding may collect.

Peritoneal Cavity

The peritoneal cavity contains many of the major abdominal organs. Its upper portion is partly protected by the lower ribs and thorax.

Structures located within or closely associated with this area include:

The lower abdominal and pelvic portions also contain loops of bowel and, in females, reproductive structures.

Retroperitoneal Space

The retroperitoneal space lies behind the peritoneal lining. Injuries in this area can be difficult to detect because bleeding may occur without obvious abdominal findings.

Important structures located completely or partly in this space include:

Pelvic Region

The pelvic cavity contains important urinary, reproductive, vascular, and gastrointestinal structures.

These include:

Because large blood vessels pass through the pelvis, significant pelvic trauma can result in substantial internal hemorrhage.

Major Abdominal Organs

Abdominal organs are often described as either solid or hollow. This distinction is important in trauma because solid organs are more likely to bleed significantly, while hollow organs may leak their contents into the abdominal cavity.

Solid Organs

The liver is the largest solid organ in the abdominal cavity and is located primarily in the right upper quadrant.

It receives a substantial blood supply through the hepatic artery and portal vein, making liver injury an important cause of internal hemorrhage after abdominal trauma.

Major liver functions include:

Because of its size and vascularity, significant liver injury can cause severe blood loss.

Spleen

The spleen is a highly vascular organ located in the left upper abdomen, behind the stomach and beneath the diaphragm. The lower ribs provide some protection.

Its functions include:

Trauma to the spleen can result in rapid internal hemorrhage, especially after blunt injury to the left upper abdomen or lower chest.

Pancreas

The pancreas lies deep within the upper abdomen, mostly behind the stomach.

Its major functions include:

Because much of the pancreas is retroperitoneal, injury may initially be difficult to recognize.

Hollow Abdominal Organs

Stomach

The stomach is a muscular hollow organ connected to the esophagus. It temporarily stores food and begins the digestive process.

Important characteristics include:

Trauma that ruptures the stomach can release acidic and contaminated contents into the abdominal cavity, potentially causing serious inflammation and infection.

Gallbladder

The gallbladder is located beneath the liver.

Its main function is to:

Although gallbladder injury is less common than injury to some other abdominal organs, rupture can lead to leakage of bile into the abdominal cavity.

Small and Large Intestines

The intestines perform essential roles in digestion, nutrient absorption, water balance, and elimination.

Small Intestine

The small intestine is primarily responsible for:

Large Intestine

The large intestine mainly:

Injury to either structure may allow intestinal contents to leak into the abdominal cavity and cause peritonitis or infection.

Genitourinary Structures

Kidneys

The kidneys are located in the retroperitoneal space on either side of the spine.

Their functions include:

Kidney injury may cause flank pain, internal bleeding, or blood in the urine.

Ureters

The ureters are muscular tubes that carry urine from each kidney to the urinary bladder.

Because they are relatively protected and narrow, isolated ureter injuries are less common but may occur with significant abdominal or pelvic trauma.

Urinary bladder

The urinary bladder is a hollow muscular organ located within the pelvis.

Its primary functions are to:

The bladder may be injured during severe pelvic trauma, particularly when it is full.

Female Reproductive Structures

Uterus

The uterus is a muscular organ located in the pelvis, generally behind the urinary bladder.

Its functions include:

During pregnancy, the uterus enlarges and rises into the abdominal cavity. Because of this increased size and blood supply, abdominal or pelvic trauma during pregnancy can place both the pregnant patient and fetus at significant risk.

Fallopian tubes

The fallopian tubes extend from the upper portion of the uterus toward the ovaries.

Their functions include:

Damage to the fallopian tubes can affect fertility and may be associated with internal bleeding depending on the injury.

Ovaries

The ovaries are paired reproductive organs located within the pelvic cavity, one on each side of the uterus. They play an essential role in reproduction by producing and releasing oocytes and by secreting hormones such as estrogen and progesterone.

Male Reproductive Structures

Several male reproductive organs are located within or near the pelvic region. Important structures include the penis, testes, vas deferens, seminal vesicles, prostate gland, and associated ducts.

The testes are located within the scrotum outside the pelvic cavity, while structures such as the seminal vesicles and prostate lie within the pelvis near the urinary bladder.

Periumbilical Region

The periumbilical region refers to the area surrounding the umbilicus, or navel. Pain, bruising, tenderness, or other abnormalities in this area may be important findings during an abdominal assessment.

Peritoneum

The peritoneum is a thin membrane that lines the abdominal cavity and covers many abdominal organs. Irritation caused by blood, digestive contents, infection, or injury may lead to peritoneal signs, including tenderness, guarding, and abdominal rigidity.

Diaphragm

The diaphragm is a dome-shaped muscular structure separating the thoracic cavity from the abdominal cavity. It plays a major role in ventilation by contracting and moving downward during inhalation.

Significant abdominal or thoracic trauma can injure or rupture the diaphragm, potentially allowing abdominal organs to move into the chest cavity and interfere with breathing.

Physiologic Effects of Abdominal Trauma

The abdomen, retroperitoneal region, pelvis, and surrounding tissues can conceal a large volume of blood following significant trauma. Because much of this bleeding is internal, patients may initially show few obvious external signs.

As blood loss progresses, the patient may develop:

The liver and spleen are particularly vulnerable because both are highly vascular solid organs. Injury to either can result in substantial internal hemorrhage.

Hollow organs such as the stomach and intestines may tolerate some blunt force, but rupture can occur when they are compressed or significantly injured. Leakage of digestive contents into the abdominal cavity may lead to peritoneal irritation, inflammation, and infection.

Serious abdominal injury should be considered when a trauma patient has:

A lack of obvious external bleeding does not rule out severe internal hemorrhage.

How Abdominal Injuries Occur

Abdominal trauma is generally classified as either blunt or penetrating. The resulting injury depends on the amount and direction of force, the organs involved, and whether compression, tearing, crushing, or penetration occurs.

Blunt Abdominal Trauma

Blunt trauma occurs when force is transferred to the abdomen without breaking the skin. Common mechanisms include motor vehicle collisions, falls, sports injuries, assaults, and impacts with fixed objects.

Blunt forces may produce:

Patients may complain of abdominal pain, tenderness, or pain referred to another location such as the shoulder. Internal bleeding may also produce guarding, rigidity, distention, or signs of shock.

Compression Injuries

Compression occurs when abdominal organs are trapped between an external force and rigid structures such as the spine or pelvis.

This may result in:

Severe compression can significantly increase intra-abdominal pressure and damage structures such as the bowel or diaphragm.

Shearing and Deceleration Injuries

Rapid acceleration or deceleration can cause mobile organs to continue moving while fixed structures remain relatively stationary. This creates shearing or tearing forces at points of attachment.

Structures that may be injured include:

These injuries may cause significant bleeding even when the abdomen initially appears normal.

Crush Injuries

Crush trauma occurs when the abdomen is forcefully compressed between objects or against a rigid surface. Solid organs may be torn or crushed, while hollow organs may rupture.

The liver, spleen, and kidneys are particularly vulnerable to severe compression because of their structure and blood supply.

Penetrating Abdominal Trauma

Penetrating injuries occur when an object passes through the skin and enters the abdominal or pelvic cavity. Common causes include stab wounds, gunshot wounds, and impalement injuries.

The severity of injury depends on:

Gunshot Wounds

Gunshot injuries may damage structures far beyond the visible entry wound because energy can be transferred through surrounding tissues.

Potentially injured structures include:

The internal path of a projectile may be unpredictable, so the extent of injury cannot be determined solely from the location of the external wound.

Stab Wounds

Stab wounds usually produce a more direct injury path than many firearm injuries, but they can still damage multiple structures.

Commonly affected organs may include:

Any penetrating wound involving the abdomen, flank, lower chest, back, or pelvis should raise concern for internal organ or vascular injury.

Key Trauma Principle

The amount of visible external damage does not necessarily reflect the severity of internal injury. EMS providers should consider the mechanism of injury, patient’s symptoms, vital signs, abdominal findings, and signs of shock when determining the urgency of treatment and transport.

Motor Vehicle Collisions

Motor vehicle crashes can produce significant abdominal injuries through compression, rapid deceleration, impact with vehicle structures, or improper restraint use. The pattern of injury often depends on the direction of impact, whether the patient was restrained, and whether ejection occurred.

Seat Belt–Related Injuries

Seat belts greatly reduce the risk of serious injury when worn correctly. However, an improperly positioned belt—particularly one placed too high over the abdomen—may compress abdominal organs and major blood vessels during sudden deceleration.

Possible injuries include:

A visible seat belt sign, such as bruising across the abdomen, should increase concern for underlying internal injury.

Rear-Impact Collisions

Rear-end crashes generally produce less direct abdominal trauma than some other collision types, particularly when the occupant is properly restrained.

However, significant injury can still occur depending on the force of the collision, position of the patient, restraint use, and secondary impacts.

Rollover Collisions

Rollover crashes may expose occupants to repeated impacts from multiple directions. The risk increases substantially when the patient is unrestrained or ejected from the vehicle.

During a rollover:

Frontal Collisions

During a head-on or frontal collision, the patient’s body may strike the steering wheel, dashboard, seat belt, or other vehicle structures.

Possible abdominal injuries include damage to the:

Rapid deceleration can also create shearing forces that injure internal organs even without direct external impact.

Side-Impact Collisions

Lateral impacts may cause significant injuries on the side of the body closest to the collision.

The patient may become compressed between the door and the center of the vehicle, placing abdominal and pelvic organs at risk. The exact injury pattern depends on the location and force of impact.

Motorcycle Crashes and Vehicle Ejection

Motorcycle riders have little structural protection around their bodies, so crashes can expose them to substantial blunt, penetrating, and friction-related trauma.

Possible concerns include:

Protective equipment can reduce certain injuries, but it cannot eliminate the risk of severe internal trauma.

Ejection from any vehicle should be considered a high-energy mechanism, especially when the patient travels a significant distance or strikes another object after leaving the vehicle.

Falls

Falls can produce abdominal injury through direct impact or sudden deceleration.

Assessment should consider:

The patient’s position at impact can provide important clues about possible injuries. Landing on the feet may transmit force upward through the legs and spine, while direct impact to the abdomen can injure internal organs.

Hard surfaces generally transfer more force to the body than surfaces that absorb or disperse some of the impact.

Blast-Related Trauma

Explosions can produce several different injury mechanisms at the same time. Blast injuries may occur in industrial accidents, military settings, mining incidents, structural explosions, or other high-energy events.

Primary Blast Injury

Primary blast injury results directly from the pressure wave created by the explosion.

Gas-containing structures are especially vulnerable, including the:

Within the abdomen, blast pressure may damage hollow organs and potentially cause delayed perforation.

Secondary Blast Injury

Secondary blast injuries occur when fragments, debris, or other objects are propelled by the explosion and strike the patient.

These injuries often resemble penetrating trauma and may damage abdominal organs, blood vessels, or other structures.

Tertiary Blast Injury

Tertiary injuries occur when the blast force throws the patient against another object or surface.

This may cause:

Quaternary Blast Injury

Quaternary blast injuries include additional effects not caused directly by the pressure wave, fragments, or bodily displacement.

Examples include:

Common Abdominal Trauma Injuries

Abdominal trauma can damage solid organs, hollow organs, blood vessels, and surrounding structures. Some injuries produce obvious external findings, while others may cause significant internal bleeding or contamination with few early signs.

Evisceration

An evisceration occurs when abdominal organs or tissue protrude through an open wound in the abdominal wall. Patients may experience localized pain, nausea, vomiting, and significant distress.

The edges of the wound can place pressure on exposed tissue and interfere with its blood supply. Proper protection of the organs is therefore important.

Management includes:

Impaled Objects

An impaled object should generally be left in place and stabilized because removing it may cause additional tissue damage or severe hemorrhage.

Important care includes:

Removal is generally performed in a controlled hospital environment unless the object creates an immediate threat to the airway, CPR, or safe transport and local protocol directs otherwise.

Solid Organ Trauma

Solid organs contain extensive blood supplies, so injury may result in substantial internal hemorrhage. Early findings can be nonspecific and may include tachycardia, abdominal tenderness, pallor, hypotension, or altered mental status.

Patients with suspected solid-organ injury require close hemodynamic monitoring and prompt transport.

Liver Trauma

The liver is large, highly vascular, and located primarily beneath the lower right ribs. Its size and blood supply make it vulnerable to significant hemorrhage after blunt or penetrating trauma.

Liver injury should be considered when there is:

Rapid deceleration may also create shearing forces at the liver’s supporting structures and blood vessels.

Splenic Trauma

The spleen is another highly vascular organ frequently injured during blunt abdominal trauma. Motor vehicle collisions, falls, sports injuries, and direct blows to the left upper abdomen can damage the spleen.

Risk may be greater when the spleen is enlarged because of an underlying medical condition.

Possible findings include:

Kehr sign, or referred pain to the left shoulder, may occur when blood irritates the diaphragm. It should not be relied upon because it may be absent or develop later.

Pancreatic Trauma

The pancreas lies deep within the abdomen, which provides some protection but can also make pancreatic injuries difficult to recognize.

Significant pancreatic trauma usually results from a high-energy mechanism such as severe blunt abdominal compression or penetrating injury.

Possible findings include:

Symptoms may not appear immediately, so the mechanism of injury remains important even when early examination findings are limited.

Diaphragm Trauma

The diaphragm may be injured by significant blunt or penetrating trauma. A tear can allow abdominal organs to move upward into the chest and interfere with normal ventilation.

Patients may develop:

Diaphragmatic injuries often occur with other serious injuries and require rapid hospital evaluation.

Hollow Organ Trauma

Hollow abdominal organs include the stomach and intestines. Injury becomes especially dangerous when these structures rupture and release their contents into the abdominal cavity.

Leakage of gastric or intestinal contents can irritate the peritoneum and eventually cause severe inflammation, infection, or peritonitis.

Small and Large Intestinal Injuries

The bowel may be injured by penetrating trauma or severe blunt compression and deceleration.

When rupture occurs, intestinal contents and bacteria may spill into the abdominal or retroperitoneal spaces.

Possible findings include:

Symptoms can sometimes be delayed after the initial injury.

Stomach Trauma

Penetrating trauma is a common mechanism of stomach injury, although severe blunt trauma can also cause rupture, particularly when the stomach is full.

If the stomach ruptures, acidic gastric contents may spill into the abdominal cavity and produce significant chemical irritation.

Possible findings include:

The severity of external findings may not reflect the extent of internal injury.

Retroperitoneal Trauma

Injuries involving the retroperitoneal space can be particularly difficult to recognize because the damaged structures lie behind the peritoneal cavity.

Patients may initially have little abdominal tenderness, distention, or obvious peritoneal irritation despite significant bleeding.

Possible delayed findings include:

Visible abdominal or flank bruising associated with internal hemorrhage may take hours or longer to become apparent and should be considered a delayed sign.

Abdominal Vascular Trauma

Major abdominal blood vessels can be injured by either blunt or penetrating trauma. Penetrating injuries may directly cut or perforate vessels, while blunt trauma can create shearing forces at fixed points of vascular attachment.

Vascular injuries may result in:

These injuries may be hidden by other traumatic findings, and the patient’s condition can deteriorate quickly. The amount of bleeding depends on the location and number of vessels involved, severity of damage, and time since injury.

Any trauma patient with unexplained hypotension, worsening perfusion, or a high-energy abdominal mechanism should be considered at risk for significant internal vascular injury and hemorrhage.

Duodenal Trauma

The duodenum may be injured during high-energy blunt trauma, particularly rapid deceleration or direct compression of the upper abdomen. Because much of the duodenum lies deep within the abdomen, injuries may initially be difficult to recognize.

If the duodenum ruptures, digestive contents can leak into the abdominal or retroperitoneal spaces, producing inflammation and infection. Symptoms may not become obvious until several hours after the injury.

Possible findings include:

Duodenal trauma is often accompanied by injuries to other abdominal structures. In children, a direct impact from bicycle handlebars to the abdomen is an important mechanism that should raise concern for significant internal injury.

Kidney Trauma

The kidneys are relatively protected within the retroperitoneal space, but substantial blunt or penetrating force can still cause serious injury.

Common mechanisms include high-speed motor vehicle collisions, significant falls, sports injuries, direct blows to the flank, and penetrating trauma.

Kidney injury should be considered when the patient has:

Blunt trauma may compress the kidney against surrounding structures, while penetrating injuries may directly damage the kidney or its blood vessels.

Bladder and Urethral Trauma

Bladder and urethral injuries frequently occur with significant pelvic or lower abdominal trauma.

Bladder Injury

The bladder is more vulnerable when it is distended with urine. High-energy pelvic trauma, improper seat-belt positioning, or pelvic fractures may result in bladder contusion, laceration, or rupture.

Possible findings include:

A bladder injury often occurs together with other significant trauma, so the entire patient should be carefully assessed.

Urethral Injury

Urethral injuries can be difficult to recognize in the prehospital setting and are commonly associated with pelvic trauma.

Possible clues include:

Suspected urethral injury requires hospital evaluation. Invasive urinary procedures should be avoided unless specifically directed by appropriate medical personnel.

Male Genital Trauma

Testicular and Scrotal Injuries

The mobility and position of the testes provide some protection, but significant direct trauma can still cause contusions, hematomas, lacerations, or testicular rupture.

Possible mechanisms include:

Possible findings include severe pain, swelling, bruising, bleeding, nausea, and difficulty walking.

Because severe testicular injury can affect fertility, prompt evaluation and definitive treatment are important.

Penile Trauma

Penile injuries may occur from blunt or penetrating trauma, sexual activity, entrapment, or other mechanisms.

A penile fracture is a tear involving the erectile tissue that usually occurs when an erect penis is forcefully bent. It is a urologic emergency requiring rapid medical evaluation.

Other penile injuries may include:

Female Genital Trauma

Trauma to the female genitalia may involve the vulva, vagina, uterus, ovaries, or surrounding pelvic structures.

Possible mechanisms include:

Potential injuries include:

Because the genital and pelvic regions are highly vascular, even apparently small injuries may result in substantial bleeding. Penetrating trauma involving the abdomen, pelvis, or upper thighs may also damage internal reproductive structures.

Prehospital Management

Serious abdominal or genitourinary injuries may be difficult to recognize early. EMS providers should maintain a high index of suspicion whenever the mechanism of injury suggests significant internal trauma.

Initial priorities include:

Specific Injury Care

Solid Organ Injuries

Suspected liver, spleen, kidney, or other solid-organ trauma requires close monitoring for internal hemorrhage. Definitive bleeding control usually requires hospital-based surgical or interventional treatment.

Scrotal and Testicular Trauma

For external scrotal wounds:

Do not attempt to replace exposed testicular tissue into the scrotum.

Penile Amputation

If part of the penis has been completely amputated:

Impaled or Entrapped Genital Objects

Objects penetrating or tightly surrounding the penis, testes, or vagina should generally not be removed in the field unless they immediately interfere with lifesaving treatment and local protocols specifically direct removal.

Instead:

Vaginal Trauma

For significant external vaginal or vulvar bleeding:

The overall goal is to recognize potentially hidden abdominal or genitourinary injury early, provide supportive trauma care, and minimize delays to definitive treatment.