Page 150 - Registrar Orientation Manual 2016

Reference:
1257
Effective date:
7 July 2015
Expiry date:
6 July 2018
Page:
33 of 35
Title:
Imaging Guidelines
Type:
Clinical Guideline
Version:
02
Authorising initials:
Lateral Cervical Spine X-ray:
The C-spine cannot always be radiologically cleared with a lateral X-Ray alone. This rarely alters treatment and may slow the trauma call process, so is generally not recommended. As a general rule, if there is enough force to cause a brain injury, there is enough to cause cervical spine injury brain and neck CT of the cervical spine and head (see below) should be done together and early.
Lateral C spine X-ray views may be useful if the hypotensive patient has a suspected cervical cord injury as the cause of their hypotension, or in a patient with severe multiple injuries including to the head and neck but requires immediate anaesthesia for damage control surgery.
Do not delay urgent surgical interventions to get C-spine X-rays - just consider the spine as being fractured and manage in a hard collar. Change to a well fitted Philadelphia or Aspen collar immediately. Shocked and unstable patients are put at increased risk if interventions are delayed by inappropriate imaging.
Cervical spine clearance should be done within 3 hours of admission to prevent problems with airway control, avoidable pain and soft tissue injury.
Abdominal/Pelvic CT:
Abdominal/Pelvic CT for trauma is highly sensitive and specific for significant injury and is the definitive test of choice in stable blunt trauma patients.
The accuracy of abdominal CT in diagnosing penetrating injury is inadequate, so penetration of the abdominal wall fascia warrants laparoscopy or laparotomy.
Clinical assessment of the abdomen is unable to exclude many occult, life-threatening injuries within the abdominal cavity. CT should be used to exclude these with knowledge of the risks of radiation.
Abdominal/Pelvic CT accurately diagnoses pelvic fractures, retroperitoneal injuries, solid organ injuries, lumbar spine fractures, sacral fractures and most hollow viscus injuries. Contrast blush in a solid organ may indicate the need for angio-embolisation in stable patients.
Hollow viscus injury can have devastating effects if it is missed and CT has a false negative rate (missed injury rate) of 10-13%.
The CT signs consistent with hollow viscus injury are:
• free air or oral contrast extravasation (hard signs); or
• free fluid, bowel thickening, mesenteric stranding and haematoma (soft signs).
Hard signs warrant laparotomy; soft signs warrant either laparotomy or careful serial examinations. Diagnostic Peritoneal Lavage is sensitive for hollow viscus injury.
The negative predictive value of contrast-enhanced abdominal CT is 99.5%.That means if the scan is negative, there is almost no chance of significant injury. Certainty in diagnosis allows other interventions to occur and enables confident decision-making in patients with multiple injuries and multiple competing priorities.
Oral contrast is not used routinely and maybe harmful in patients who are at risk of aspiration. lf contrast is to be used; follow the Trauma Protocol.
Chest CT:
CT of the chest gives detailed information on the chest and its contents and can reveal injuries that are not well defined by plain radiology. Most thoracic injuries do not require chest CT, with some notable exceptions.