Penetrating abdo trauma

Pre-hospital and ED management:

• Military style scoops rather than on-scene resus
• 'Hypotensive resuscitation'
• FAST in ED
• IV Abx
• Aim to get to OT within 10 minutes of arrival in ED
• Intubate in ED if:
  • Profound hypotension or recent CPR
  • Associated wounds to neck or chest affecting airway or breathing
  • Depressed neurologic state secondary to shock, acute alcoholism or drugs
  • Extreme agitation preventing evaluation and resuscitation
• When to consider chest - POSSIBLE penetrating thoracoabdominal trauma
  • Defined as nipple to costal margin between midline and anterior axillary line
  • Possible for diaphragm and thorax to be involved
  • Penetration into peritoneum will occur with 15% of stab wounds and 45% gunshot wounds
  • Algorithm
    • FAST positive and unstable: OT
    • FAST positive and stable
      • CT (Cameron's says with IV, oral and rectal contrast)
      • Left diaphragmatic defects must be repaired, whereas right do not
      • Equivocal CT should be followed by diagnostic laparoscopy
  • Schein's suggests non-urgent laparoscopy for all lower chest or upper abdominal penetrating trauma, to exclude diaphragmatic injury, especially on left

Indications for laparotomy:

• Positive FAST and unstable patient
• Hypotension in absence of other site of potential haemorrhage
• Peritonitis on initial or subsequent examination (needs to be established separately to the wound - all large wounds cause local guarding)
• Evisceration of bowel (and maybe omentum… controversial)
• Bleeding from stomach or rectum
• CT shows viscus perforation, intraperitoneal bladder injury or solid organ injury that needs operation (spleen, liver)
• Free air on CXR
• Retained stabbing instrument

Specific situations:

Anterior stab wound

• • Between costal margin and inguinal ligament anteriorly
  • Try not to make treatment decisions based on reported length of knife etc - treat the patient not the weapon
  • Stab wounds penetrate peritoneum 25% of the time, and 50% of those with peritoneal penetration will require laparotomy
  • If unsure whether there has been a peritoneal breach, but the CT was normal and the patient is asymptomatic, Schein's suggests observation over 24 hours.
    • In a patient of normal weight who is co-operative, local wound exploration is indicated (apparently do it in ED in USA but seems more likely to be done in OT here). Some centres would suggest terminating exploration once it is confirmed that the anterior muscular layer is breached, while others would suggest continuing to dissect down to posterior peritoneum or posterior aponeurosis. If no peritoneal access, the wound can be irrigated and closed in layers.
    • However, this can be difficult and inconclusive, so Schein's suggests going on other clinical signs to decide whether significant intra-peritoneal injury has occurred.
  • An asymptomatic patient with penetration of muscle layer or peritoneum needs a diagnostic laparoscopy or at least 24 hours of serial examination. Almost all patients with bleeding or perforation will become symptomatic within 16 hours.
    • Another option is to perform DPL, with a red cell cut-off for indicating laparotomy of between 5,000 to 100,000, but this is old-fashioned.

Eviscerated omentum through anterior wound

• • Controversial
  • Non-therapeutic laparotomies about 50% in this setting
  • Many centres would ligate the base of the omentum, excise it and return it to peritoneum with ongoing observation

Flank or back penetrating trauma

• • Defined as sixth IC space to iliac crest between anterior and posterior axillary lines
  • Back is tips of scapulae to iliac crests posterior to posterior axillary line
  • High risk for colon injury, and peritonism/deterioration can only occur late
  • FAST and examination are unreliable, but may still be useful to exclude tamponade
  • If haemodynamically stable, obviously goes for CT (+/- rectal contrast) followed by 24-36 hours observation

Gunshot wound

• • Traditionally, explore them all. However, new evidence suggests they can be managed similarly to stab wounds - only explore those with an indication which suggests significant underlying injury.
  • CT of whole torso is mandatory
  • Shotgun injuries - range is most important thing - less than 3 metres are often fatal, with mandatory surgery; 3-7 metres will usually penetrate the abdominal wall, so laparotomy is usually indicated; 7-20 metres produces scattered wounds with pellets in skin and fascia; and >20 metres seldom needs much treatment.

Impalement

• • Explore all, to remove safely in OT