Introduction

Abdominal trauma accounts for 22% of body regions injured in major trauma and can be difficult to diagnose and manage2. A high index of suspicion should be maintained for any multi-trauma patient, particularly where the mechanism of injury may suggest significant abdominal injury. Understanding the types of injuries is important for the planning and organisation of trauma services. Penetrating injuries are frequently isolated injuries, but may cause severe organ or vessel disruption and rapid bleeding. Securing breathing and control of bleeding are often the priorities with this type of injury.
The vast majority (over 90%) of major trauma in Australia is caused by blunt injury mechanisms, such as those caused by motor vehicle collisions (MVC), falls, and being forcefully struck. Blunt injuries less often present with rapid exsanguination, but are more often associated with multiple organ failure, combinations of airway, breathing, circulatory, neurological and musculoskeletal deficiencies, and permanent physical and cognitive disabilities among survivors.
Missed abdominal injuries are a major cause of avoidable death in trauma patients3. The principles of initial management focus on the detection of any injury and determining the need for urgent intervention. Investigations such as the Focused Assessment of Sonography in Trauma (FAST) and Computerised Tomography (CT) scanning can determine the presence of injuries in combination with assessment.
 

Blunt abdominal trauma

Blunt abdominal injuries may be initially difficult to detect if the patient has no signs of external trauma and alteration to their vital signs. Significant blood loss can occur without any dramatic change in appearance of the abdomen. A direct blow from blunt trauma can lead to solid organ rupture and visceral damage causing haemorrhage, contamination with the visceral contents, peritonitis and associated pelvic injuries. The most common organs injured are the spleen, liver and small bowel. Shearing injuries caused by improperly worn seatbelts are a form of crush injury that can display an identifiable seatbelt pattern of bruising.
Physical examinations signs following blunt abdominal trauma should raise suspicion of a severe injury when the following are present: seatbelt injury, rebound tenderness, hypotension BP<90, abdominal distension, abdominal guarding and concomitant femur fracture.4

Indications for emergency laparotomy – blunt trauma
  • Peritonism.
  • Free air under the diaphragm.
  • Significant gastrointestinal hemorrhage.
  • Hypotension with positive FAST scan or positive DPL.
  • Increasing abdominal pain.
  • High grade solid organ injuries if embolisation not available.
  • Physiological deterioration.
 
Recent developments in trauma surgery favour a conservative approach to preserve the spleen or kidney following injury whenever clinically appropriate and possible5.  Splenectomy can be life-saving if injuries are time critical or life threatening.
Haemodynamically stable blunt solid organ injuries should be managed in trauma services where facilities exist to closely monitor for clinical deterioration.  

Penetrating abdominal trauma

Penetrating injuries tend to be obvious and dramatic. The most commonly injured intra-abdominal organs are the small intestine, liver and colon. Of these only one third will penetrate the peritoneum & only 50% of these will require surgical intervention. In contrast, 85% of abdominal gun-shot wounds (GSW) penetrate the peritoneum & 95% of these require a surgical intervention.
Where a penetrating object impales the patient, it should not be removed as the object potentially acts as a tamponade and any removal may lead to catastrophic haemorrhage. Removal should only take place in a controlled surgical environment with appropriate resources for intervention and resuscitation.

Indications for emergency laparotomy – penetrating trauma:
  • Penetrating abdominal trauma + hypotension.
  • Peritonism.
  • Free Air.
  • Evisceration.
  • GSW traversing peritoneum.

Solid organ versus hollow viscus injury

There are many different mechanisms of injury that leads to the compressive and shear forces that damage abdominal organs. Significant deceleration or compression forces occur in MVC’s or falls from height. Significant injuries can also occur from mechanisms such as assaults or sporting activities leading to splitting of the structure and in a hollow organ may cause rupture.6
Shearing forces created by sudden deceleration can cause lacerations of both solid and hollow organs at their points of attachment to the peritoneum. They may also create tears or cause stretch injuries to the arteries, resulting in infarction of the distal organ. Fractured ribs or pelvic bones can lacerate intra-abdominal tissue.
Diaphragmatic & pancreatic injuries are frequently missed on initial CT scanning. Delay in diagnosis and treatment of hollow viscus injury leads to an increase in mortality and morbidity.