12.3 Abdominal Trauma

The abdomen is a black box that Boyle's law and a loud cabin make blacker. Domain 3.E of the August 2026 Board of Certification for Emergency Nursing (BCEN) Certified Flight Registered Nurse (CFRN) outline tests abdominal trauma—hollow viscus, solid organ, diaphragmatic, and retroperitoneal injuries—because a negative ultrasound does not mean an empty tank and because bowel in the chest expands on climb. Burns stay in Chapter 13. Pelvic packaging details continue in section 12.4; hemorrhage physiology sits in Chapters 8 and 10.

Hollow viscus: the seat-belt and the late belly

Hollow-viscus injury is bowel or bladder that tears or shears. The classic roadside clue is a seat-belt sign: a linear contusion across the abdomen, often with a Chance-type lumbar fracture in the same flexion-distraction story. Early extended focused assessment with sonography for trauma (eFAST) is often negative because the problem is perforation and mesenteric ischemia, not a liter of free fluid yet. Peritonitis can declare in hours: rising pain, rigidity, fever, and a patient who looked stable at the landing zone. Do not clear the abdomen because the first scan is dry. Do not delay the aircraft for a second scan that still cannot see a pinhole in ileum.

A gastric tube that suddenly drains blood, a rigid abdomen after climb, or progressive shock without an external puddle should make you think hollow viscus plus a second occult site. Support perfusion with blood if they are bleeding (Chapter 8), keep them warm (Chapter 10 trauma diamond), and fly to a surgeon.

Solid organs: hypotension is the problem

The spleen, liver, and kidney are the solid organs that empty the tank. The spleen is the most common blunt bleeder. The liver can hide a surprising volume under the right costal margin. The kidney bleeds into the retroperitoneum and may show hematuria—or may not. In flight, hypotension is the problem, not the organ name. You cannot grade a splenic laceration in a vibrating cabin. You can recognize shock, start blood, avoid drowning a coexisting pulmonary contusion in salt water, and choose a hospital that can operate or send the patient to interventional radiology (IR) for embolization.

Diaphragm: bowel in the chest, left more than right

Diaphragmatic rupture is more often left-sided in blunt trauma because the liver splints the right hemidiaphragm. Hollow viscera slide into the chest. The sending film may show a nasogastric tube coiling above the expected diaphragm, a bowel pattern in the hemithorax, or a poorly defined hemidiaphragm. Cabin auscultation will not give you reliable bowel sounds in the chest. Treat the image and the mechanism.

Boyle expansion of herniated viscera

Herniated stomach or bowel is a gas-filled bag. As cabin altitude rises, that bag expands, crowds the lung, kinks the mediastinum, and can worsen shock. Decompress the stomach with a working nasogastric (NG) or orogastric tube if the airway is protected and the tube is not coiled in a way that proves the hernia—you still leave it to drainage. Request a lower cabin. This is not a chest-seal problem and not a reason to clamp a bubbling pleural tube on the other side.

Retroperitoneum, FAST limits, binder, destination

The retroperitoneum hides the pelvis, pancreas, duodenum, and great vessels. Blood loss can be occult: a flat-looking belly, a negative FAST, and a patient who is still dying. Pancreatic and duodenal injuries are often deceleration or epigastric-blow problems that declare late with enzymes and peritonitis. Vascular retroperitoneal injury is a time-to-OR problem. Grey-Turner flank staining, if you ever see it, is late.

eFAST limits you must not forget:

• It cannot clear hollow viscus.
• It cannot clear retroperitoneal hemorrhage.
• It cannot grade a solid-organ injury you already know is bleeding.
• It cannot exclude diaphragmatic hernia.
• A negative scan is not a reason to stay on the ramp.

Do not delay transport for a negative FAST. The scan is a rule-in tool for free intraperitoneal or pericardial fluid when you are trained to use it. It is not a discharge test. If the pelvic ring is unstable or the mechanism plus shock says pelvis, apply a pelvic binder (section 12.4) and stop rocking the pelvis to satisfy curiosity.

Destination is a trauma center with a capable operating room (OR) and IR, not the nearest hospital that can repeat an ultrasound. Solid-organ embolization, damage-control laparotomy, and pelvic packing or angioembolization are receiving-team tools. Your tools are blood, warmth, a binder, a decompressed stomach, a cabin that does not inflate herniated bowel, and a refusal to wait for a prettier picture.