Introduction
Patients with abdominal trauma are often complex to assess, manage, and treat. In most cases, these injuries are not fully resolved in the prehospital setting. The abdominal cavity is especially vulnerable because it contains many critical organs and structures. According to the National Center for Injury Prevention and Control, trauma is the leading cause of death in individuals aged 1–44 years. Genitourinary injuries occur in about 10–20% of major trauma cases and in roughly 2–5% of all trauma patients.
Anatomy & Physiology
Abdominal Regions
Right Upper Quadrant (RUQ):
Contains most of the liver, right kidney, gallbladder, a portion of the pancreas, part of the colon, and small intestine.
Left Upper Quadrant (LUQ):
Contains part of the liver, spleen, left kidney, stomach, most of the pancreas, portions of the colon, and small intestine.
Right Lower Quadrant (RLQ):
Contains the appendix, right ureter, small intestine, and colon. In females, it also includes the right ovary and fallopian tube.
Left Lower Quadrant (LLQ):
Contains the colon, small intestine, left ureter, and in females, the left ovary and fallopian tube.
Additional Abdominal Areas
Peritoneal Cavity:
- Upper portion lies beneath the lower thorax and includes the diaphragm, liver, spleen, stomach, gallbladder, and transverse colon.
- Lower portion is enclosed by the peritoneum and contains the small bowel, sigmoid colon, and parts of the ascending and descending colon.
- In females, it also contains reproductive organs.
Retroperitoneal Space:
Located behind the peritoneum and contains the abdominal aorta, inferior vena cava, pancreas, kidneys, ureters, and parts of the duodenum and colon.
Retroperitoneal Pelvic Cavity:
Includes the rectum, bladder, ureters, iliac vessels, pelvic vascular structures, skeletal structures, and reproductive organs.
Organs
Solid Organs
Liver:
The largest abdominal organ with a rich blood supply from the hepatic artery and portal vein. It holds about 13% of total blood volume. Liver injuries are dangerous due to severe bleeding risk. The liver detoxifies blood, processes hemoglobin, regulates clotting, supports immune function, removes bacteria, and helps metabolize fats.
Spleen:
A highly vascular organ located under the diaphragm and behind the stomach, partially protected by the lower left ribs. It stores and filters blood, recycles iron, and produces immune cells. Injury can cause severe hemorrhage.
Pancreas:
Located behind the stomach and under the liver. It produces digestive enzymes and hormones for endocrine function.
Hollow Organs
Stomach:
Connected to the esophagus and contains food and fluids. It receives blood from the celiac trunk and drains via the portal system. It is controlled by autonomic nerves and produces strong acid (pH 1.5–3) for digestion.
Gallbladder:
Found beneath the liver and stores bile produced by the liver.
Small and Large Intestines:
Responsible for digestion, absorption of nutrients, and water balance.
Genitourinary System
Kidneys:
Located in the retroperitoneal space; they filter blood and remove waste.
Ureters:
Muscular tubes that transport urine from the kidneys to the bladder.
Urinary Bladder:
A muscular organ in the pelvis that stores urine until elimination.
Female Reproductive Organs
Uterus:
Located behind the bladder in the pelvis; supports implantation and fetal development. It enlarges significantly during pregnancy, increasing injury risk during trauma.
Fallopian Tubes:
Connect the uterus to the ovaries and transport the egg for fertilization.
Ovaries:
Produce eggs and hormones and are located on each side of the pelvic cavity.
Other Structures
- Periumbilical region: Area around the navel
- Peritoneum: Membrane lining the abdominal cavity
- Mesentery: Tissue that attaches organs to the abdominal wall
- Male reproductive organs: Penis, testes, and ductus deferens located outside the pelvis
- Diaphragm: Muscle separating thoracic and abdominal cavities, essential for breathing
Physiology Considerations
Internal cavities (abdominal, retroperitoneal, and muscle compartments) can trap large volumes of blood, leading to shock. Because the abdomen can hold significant blood loss, symptoms may be delayed. Liver and spleen injuries are common and can bleed heavily. Hollow organs are more resistant unless full, in which case rupture may spill contents into the abdomen causing peritonitis. Unrecognized abdominal injury is a major cause of preventable death due to delayed treatment. Signs like unexplained hypotension after trauma should raise concern for internal bleeding. As blood loss worsens, patients may become confused or agitated.
Mechanisms of Injury
Blunt Trauma
Accounts for about two-thirds of abdominal injuries and may involve compression, crushing, or shearing forces. Symptoms can include abdominal pain, rigidity, and referred shoulder pain due to internal bleeding.
- Compression injuries: Caused by direct force, may rupture hollow organs or increase abdominal pressure
- Shearing injuries: Organs tear or detach, causing internal bleeding
- Crush injuries: Organs are compressed between structures, damaging both solid and hollow organs
Penetrating Trauma
Caused by objects such as knives or bullets. Gunshot wounds typically cause more extensive damage due to higher energy transfer and cavitation. Commonly affected organs include the bowel, liver, and blood vessels.
Motor Vehicle Crashes
- Seatbelt injuries: Incorrect placement may compress abdominal organs
- Rear-impact collisions: Lower risk if restrained properly
- Rollovers: Highest risk for severe or fatal injuries, especially if unrestrained
- Frontal impact: Can injure abdominal organs against the dashboard
- Side impact: May crush the abdomen between door and console
- Motorcycle crashes: High risk of severe trauma due to lack of protection
Falls & Blast Injuries
Falls are evaluated based on position at impact and surface type. Blast injuries include:
- Primary: effects on gas-filled organs
- Secondary: projectile injuries
- Tertiary: body displacement injuries
- Quaternary: burns and heat exposure
Types of Injuries
Evisceration
Abdominal organs protrude through a wound. Do not push organs back in. Cover with sterile saline dressing, keep warm, manage pain, and transport quickly.
Impaled Objects
Do not remove. Stabilize object and transport carefully.
Solid Organ Injury
May cause internal bleeding without obvious signs. Requires rapid transport and monitoring.
Organ-Specific Injuries
- Liver: Highly vascular; prone to severe bleeding, especially with right-sided rib fractures
- Spleen: Commonly injured in blunt trauma; can cause rapid blood loss
- Pancreas: Rare injury but often serious; may cause delayed symptoms and diabetes
- Diaphragm: Injury leads to breathing problems and often occurs with other trauma
- Intestines: Common in penetrating trauma; rupture causes infection and peritonitis
- Stomach: Rupture leads to chemical peritonitis and rapid abdominal pain
- Retroperitoneal organs: Injuries are hard to detect and often delayed
- Kidneys: Often injured in high-energy trauma; hematuria is common
- Bladder: Rupture associated with pelvic fractures and high-force trauma
Management Principles
Maintain high suspicion for abdominal injury in any significant trauma. Rapid transport is essential for solid organ injuries. Do not remove impaled objects or vaginal/urethral foreign bodies in the field. Control external bleeding with compression. Provide supportive care, pain management, and emotional support when appropriate.