What is a hemoperitoneum in a patient with potential abdominal trauma or spontaneous rupture of an abdominal organ or vessel?

What is a Hemoperitoneum?

Hemoperitoneum is the presence of blood within the peritoneal cavity, which can result from traumatic injury (blunt or penetrating abdominal trauma) or spontaneous rupture of abdominal organs, blood vessels, or tumors. 1, 2

Definition and Clinical Context

• Hemoperitoneum refers to blood accumulation in the peritoneal space, with a minimum of approximately 500 mL typically required for detection by emergency ultrasound imaging 3
• In traumatic settings, hemoperitoneum most commonly results from blunt abdominal trauma causing injury to solid organs (liver, spleen) or hollow viscus structures 1
• In non-traumatic settings (spontaneous hemoperitoneum), blood accumulates from rupture of organs, vessels, or tumors without external trauma 2, 4

Traumatic Hemoperitoneum

Common Causes

• Solid organ injuries (liver, spleen) are the most frequent sources in blunt abdominal trauma 1
• Pelvic fractures account for 55% of retroperitoneal hematomas in blunt trauma and are associated with increased transfusion requirements 5
• Penetrating injuries with trajectories through the abdomen can cause hemoperitoneum from any intra-abdominal structure 1

Clinical Significance

• The volume of hemoperitoneum correlates with injury severity - abundant hemoperitoneum (3 positive E-FAST sites) is associated with 61% need for laparotomy 3, 6
• Hemodynamic instability in the presence of hemoperitoneum indicates active bleeding requiring urgent intervention 1, 3

Spontaneous (Non-Traumatic) Hemoperitoneum

Common Causes

• Hepatocellular carcinoma and hepatic adenoma are the most common causes of spontaneous hemoperitoneum 4, 7
• Ruptured abdominal aortic aneurysm represents a critical vascular cause requiring immediate intervention 5, 7
• Anticoagulation therapy is an important risk factor for spontaneous retroperitoneal and intraperitoneal bleeding 5
• Gynecologic sources including ruptured ectopic pregnancy, ovarian cysts, or rarely bleeding uterine leiomyomas 8
• Splenic rupture from underlying pathology (infection, malignancy, or idiopathic) 7
• Metastatic tumors can spontaneously rupture, though this is rare 4

Clinical Presentation

• Spontaneous hemoperitoneum often presents with sudden onset abdominal pain, distention, and signs of hypovolemia 4, 8
• Diagnosis may be delayed due to nonspecific symptoms including diffuse abdominal pain, back pain, or flank mass 5
• The condition is potentially life-threatening and requires high clinical suspicion in the emergency setting 2, 7

Diagnostic Approach

Initial Assessment

• E-FAST (Extended Focused Assessment with Sonography for Trauma) is the first-line imaging modality for rapid detection of free fluid in the peritoneal cavity 3, 6
• E-FAST has 68-91% sensitivity and excellent specificity for detecting hemoperitoneum, with 100% sensitivity and specificity in hypotensive patients 1, 3
• At least 500 mL of blood must be present for detection by ultrasound, meaning early or slowly bleeding injuries may be missed 3

Advanced Imaging

• CT scan with intravenous contrast is the gold standard for hemodynamically stable patients, providing detailed information about bleeding source and injury extent 1, 3
• CT has 93.9% sensitivity and 77.8% specificity for detecting active bleeding 3
• Delayed-phase CT imaging can identify active bleeding in solid organs through contrast pooling 1

Historical Diagnostic Methods

• Diagnostic peritoneal lavage (DPL) was historically used to rapidly identify hemoperitoneum with 98% sensitivity 1
• DPL is positive when: (1) 5-10 mL of frank blood is aspirated, (2) RBC count >100,000/mL in effluent, or (3) WBC count >500/mL in effluent 1
• DPL can detect as little as 20 mL of intraperitoneal blood but has largely been replaced by E-FAST and CT 1

Important Clinical Pitfalls

• A negative E-FAST does not exclude hemoperitoneum if performed very early or if less than 500 mL of blood is present 3, 6
• Blood clots can form rapidly in the peritoneum and have sonographic qualities similar to soft tissue, potentially being overlooked 3
• Perinephric fat may be mistaken for hemoperitoneum on ultrasound 3
• E-FAST has poor sensitivity for retroperitoneal hemorrhage, which requires CT imaging for detection 6, 5
• Bowel and mesenteric injuries are more difficult to detect with E-FAST alone and may require CT or surgical exploration 1, 6

Management Implications

• Hemodynamic instability with hemoperitoneum requires immediate resuscitation and urgent intervention (surgery or angioembolization) 1, 3
• Hemodynamically stable patients should undergo CT imaging for complete injury assessment before definitive management 1, 3
• Intraperitoneal bladder rupture with hemoperitoneum requires surgical repair to prevent peritonitis and sepsis 1
• For spontaneous hemoperitoneum, management depends on the underlying cause and may include angioembolization or surgical intervention 7