Introduction

• Trauma to the abdomen can be extremely difficult to assess even in a hospital setting. In the field, identifying which abdominal structure(s) has been injured is less important than identifying that abdominal trauma itself has occurred.

• It is therefore of major importance to note abnormal signs associated with blood loss and to establish that abdominal injury is the probable cause, rather than being concerned with, for example, whether the source of that abdominal bleeding originates from the spleen or liver.

• There may be significant intra-abdominal injury with very few, if any, initial indications of this at the time the abdomen is examined by the paramedic at the scene.

Pathophysiology

The abdomen may be described as three anatomical areas:

• Abdominal cavity

• Pelvis

• Retro-peritoneal area

• Abdominal cavity – extends from the diaphragm to the pelvis. It contains the stomach, small intestine, large intestine, liver, gall bladder and spleen. The upper abdominal organs are partly in the lower thorax and lie under the lower ribs; therefore, fractures of lower ribs may damage abdominal structures such as the liver and spleen.

• Pelvis – contains the bladder, the lower part of the large intestine and, in the female, the uterus and ovaries. The iliac artery and vein overlie the posterior part of the pelvic ring and may be torn in pelvic fractures, adding to already major bleeding.

• Retro-peritoneal area – lies against the posterior abdominal wall, and contains the kidneys and ureters, pancreas, abdominal aorta, vena cava and part of the duodenum. These structures are attached to the posterior abdominal wall, and are often injured by shearing due to rapid deceleration forces.

Abdominal Injuries

• Blunt trauma – the most common pattern of injury seen; results from direct blows to the abdomen or rapid deceleration. Blunt trauma may also result from all phases of a blast.

  • The spleen, liver (hepatic tear) and ‘tethered’ structures such as the duodenum are the most commonly injured. The small bowel, mesentery and aorta may also sustain injury.

• Penetrating trauma – stab wounds, gunshot wounds, blast injuries and other penetrating injuries.

  • Stab wounds – stab injures should be assumed to have caused serious damage until proved otherwise. Damage to liver, spleen or major blood vessels may cause massive haemorrhage. NB Upper abdominal stab wounds may have caused major intra-thoracic damage if the weapon was directed upwards (refer to Thoracic Trauma). Similarly, chest-stabbing injuries may also cause intra-abdominal injury.

  • Gunshot wounds – tend to cause both direct and indirect injury, due to the forces involved and the chaotic paths that bullets may take. The same rules apply to associated intra-thoracic injuries.

  • Blast injuries – can lead to both blunt and penetrating injuries. Where an explosion occurs in a confined space, the blast wave can cause injuries to the bowel (perforation and haemorrhage) and penetrating ballistics can lead to organ damage.