Chapter 26. Abdominal and genitourinary trauma
A high index of suspicion is mandatory in potential abdominal trauma as signs and symptoms may be subtle or evolve slowly.
Mechanisms of injury
Three mechanisms of injury exist – blunt, penetrating and blast. In the majority of instances, injury results from blunt impact following a road traffic accident, sporting accident, fall or industrial accident. Blast injuries are fortunately rare.
Blunt injuries
Blunt impact results in definable injury patterns:
Bursting
Sudden, violent compression of the abdominal wall may dramatically raise intra-abdominal pressure leading to rupture of a bowel loop. An incorrectly fitted seatbelt is a common factor in these injuries.
Crush
Direct crush injuries occur when a viscus is injured by directly applied pressure. A common event is rupture of the retroperitoneal portion of the duodenum in bicycle accidents – the duodenum is compressed between a handlebar and the lumbar spine. The pancreas, liver and spleen are also readily injured in this way.
Shear
Shear force injuries occur when force is applied tangentially across vascular pedicles; structures at risk include the spleen, liver and small bowel mesentery. These injuries are commonly associated with sudden deceleration.
Collision
Collision injuries result typically from impact of a motor vehicle on a pedestrian. The pattern of injury will depend on the size of the victim – bumper (fender) impact on an adult usually involves the limbs and abdominal injury is relatively uncommon, but in a child the torso takes the brunt of the force and abdominal and chest injury should be assumed in the prehospital setting.
Ejection
Ejection from a vehicle can result in multiple injuries, including damage to the cervical spine, depending on how the casualty lands – the torso is a large target and the likelihood of abdominal injury under these circumstances is high.
Injury to the chest + injury to the pelvis = injury to the abdomen until proven otherwise
Penetrating injuries
Intra-abdominal penetration may be obvious however penetrating objects, bullets, fragments, knives or damaged vehicle parts can reach the abdomen from the lower chest, the back, flanks, buttocks and perineum. In the case of bullets and missile fragments, the entry site may be anywhere, as they may travel unpredictable distances and readily deflect from their original line of flight.
Recognition of injury
As many as 20% of patients with significant intraabdominal bleeding reveal little or nothing in the way of physical signs.
Event history
The event history may be provided by the patient, other victims or bystanders. It is frequently unavailable.
Initial clinical assessment
In the primary survey, the first indication of abdominal trauma typically arises during assessment of circulation. Another clue may be when the extent of shock is out of proportion to the observed injuries. If shock is not a particular feature and the patient is readily stabilised, the secondary survey may reveal tenderness, rebound tenderness or even rigidity.
In particular, the paramedic should:
• Expose the abdomen as far as possible
• Inspect or look at the abdomen, including flanks, lower chest, back and pelvic region
• Palpate the abdomen, including the flanks and as much of the back as possible
• Wounds, bruises or abrasions should raise the level of suspicion.
The history in abdominal injury
Details of the following should be established:
• History of event
• Pain
• Location
• Radiation: is pain present in the shoulders or back
• Wounds
• Wounding instrument
• Loss of consciousness
• Presence of drugs or alcohol
• Obvious distracting injuries elsewhere.
Establishing a specific diagnosis is not necessary: assess the likelihood of injury being present and arrange expeditious transport to hospital
Genitourinary trauma
Genitourinary trauma and abdominal trauma are normally considered together.
Because the kidneys and ureters lie in the retroperitoneal space, injury is often silent and easily missed. Haematuria is not a constant feature.
However, blood at the external urinary meatus or an inability to pass urine are clear signs of injury.
The lower urinary tract is also vulnerable to injury following pelvic trauma. There is little to be done in the prehospital setting apart from injury recognition, understanding the implications and transporting the patient to hospital as a priority.
Pelvic fractures
Pelvic fractures are common components in multisystem injury and they should be particularly looked for.
The more severe pelvic fractures are usually associated with high-speed impact and should therefore be suspected from the history and mechanism of injury.
• These are critical injuries to recognise. Unstable, complex pelvic injuries are associated with a very high mortality rate, principally due to uncontrolled haemorrhage
• Physical examination and extrication should be handled with great care
• Consider the application of a specialised pelvic splint. More simple techniques include the application of a pelvic binder or drawsheet
• In the absence of palpable radial pulses, initial management may require repeated 250 mL aliquots of crystalloid. This should be started en route to hospital if the patient is not trapped. Rapid transportation to hospital is of paramount importance. Large volumes of whole blood are typically needed and some patients will continue to haemorrhage until the pelvis is stabilised by operative fixation.
Abdominal trauma in pregnancy
The pregnant uterus remains inside the protection of the bony pelvis until the 12th week of gestation and pregnancy therefore may not be obvious, particularly in an unconscious patient.
After 12 weeks, the uterus rises above the pelvic brim and is palpable. The possibility of pregnancy should always be considered in a woman of childbearing age and should be actively sought.
The best possible care for the fetus is optimal care for the mother and this must be the aim.
Trauma to the abdomen in later pregnancy when the uterus is thin-walled may result in uterine rupture or placental abruption associated with significant blood loss.
Shock management must be prompt and vigorous and the patient quickly transported to hospital. Remember the problem of postural hypotension due to compression of the inferior vena cava by the gravid uterus, which may require manual displacement of the uterus to the left, elevation of the right hip or, if a spine board is available, tipping the spine board and patient towards the left side at a 30° angle during transportation.
Treating the mother well is the best treatment for the foetus
For further information, see Ch. 26 in Emergency Care: A Textbook for Paramedics.
