ATLS Abdominal and Pelvic Trauma 2 — Questions and Answers

Question 1: A patient arrives after a motorcycle crash with a rigid, distended abdomen and hypotension. What is the most appropriate initial diagnostic study?

CT scan with IV contrast
Focused Assessment with Sonography for Trauma (FAST) (Correct answer)
Diagnostic peritoneal lavage
Abdominal X-ray

Correct answer: Focused Assessment with Sonography for Trauma (FAST)

FAST is the preferred initial assessment in hemodynamically unstable trauma patients as it rapidly identifies free intraperitoneal fluid without delaying resuscitation.

The FAST exam is a bedside ultrasound that evaluates for free fluid in the peritoneal cavity, pericardium, and pleural spaces. In hemodynamically unstable patients, FAST provides rapid results without transport. A positive FAST in an unstable patient typically indicates need for emergent laparotomy. CT is reserved for hemodynamically stable patients. DPL has largely been replaced by FAST in most trauma centers.

Question 2: Which organ is most commonly injured in blunt abdominal trauma?

Liver
Spleen (Correct answer)
Kidney
Small bowel

Correct answer: Spleen

The spleen is the most commonly injured solid organ in blunt abdominal trauma due to its anatomic position and relatively fragile parenchyma.

The spleen is the most frequently injured organ in blunt abdominal trauma, accounting for approximately 40-55% of solid organ injuries. Its subcapsular location beneath the left lower ribs, friable parenchyma, and rich blood supply make it vulnerable. Management ranges from observation with serial exams to splenectomy depending on grade and hemodynamic stability.

Question 3: A stab wound to the left lower chest at the 7th intercostal space should raise suspicion for injury to which abdominal organ?

Right kidney
Spleen (Correct answer)
Bladder
Pancreas

Correct answer: Spleen

The thoracoabdominal region contains the upper abdominal organs beneath the diaphragm, and left-sided wounds in this zone frequently injure the spleen.

Penetrating wounds between the nipple line (4th intercostal space) and costal margin are considered thoracoabdominal injuries. The diaphragm can rise as high as T4 during expiration, meaning organs like the spleen, liver, and stomach lie within this zone. A left-sided wound at the 7th intercostal space is directly over the spleen.

Question 4: What is the most reliable indicator of intra-abdominal hemorrhage requiring surgical intervention in an unstable trauma patient?

Elevated serum lactate
Positive FAST exam (Correct answer)
Falling hemoglobin on serial labs
Base deficit greater than 6

Correct answer: Positive FAST exam

A positive FAST exam in a hemodynamically unstable patient is the most reliable bedside indicator of significant intra-abdominal hemorrhage requiring emergent surgical exploration.

While lactate, hemoglobin trends, and base deficit all reflect the physiologic consequences of hemorrhage, they are indirect markers. A positive FAST exam directly demonstrates free intraperitoneal fluid, which in the setting of trauma and hemodynamic instability indicates hemorrhage requiring operative intervention.

Question 5: A hemodynamically stable patient with a Grade III splenic laceration on CT is best managed with which approach?

Emergent splenectomy
Nonoperative management with observation (Correct answer)
Splenic artery embolization only
Diagnostic peritoneal lavage

Correct answer: Nonoperative management with observation

Hemodynamically stable patients with Grade I-III splenic injuries are typically managed nonoperatively with serial abdominal exams, hemoglobin monitoring, and bed rest, achieving success rates of over 90%.

Nonoperative management (NOM) of splenic injuries has become the standard of care for hemodynamically stable patients with Grade I-III injuries. NOM includes ICU admission, serial abdominal exams, serial hemoglobin checks, and activity restriction. Success rates exceed 90% for these grades.

Question 6: Which finding on diagnostic peritoneal lavage (DPL) is considered positive for significant intra-abdominal injury?

RBC count >50,000/mm3
RBC count >100,000/mm3 in blunt trauma (Correct answer)
WBC count >100/mm3
Amylase level >100 IU/dL

Correct answer: RBC count >100,000/mm3 in blunt trauma

A red blood cell count exceeding 100,000/mm3 in the DPL effluent is the standard threshold for a positive result in blunt trauma.

DPL criteria for a positive result in blunt trauma include: gross blood aspiration (>10 mL), RBC count >100,000/mm3, WBC count >500/mm3, or presence of bile, bacteria, or food fibers. For penetrating trauma, the RBC threshold is lower at >5,000-10,000/mm3.

ATLS Abdominal and Pelvic Trauma 2

A patient arrives after a motorcycle crash with a rigid, distended abdomen and hypotension.
What is the most appropriate initial diagnostic study?