Imaging in the Trauma Patient David A. Spain, MD Department of Surgery Stanford University
Pan Scan Instead of Clinical Exam?
Granted, some patients don’t need CT scan…
Platinum Package – Stanford Special
CT Scan
Head Neck Chest Abdomen Pelvis With T/L spine reformats
Takes about 30 minutes to do
LightSpeed The Power to Scan. Finer. Faster. Further.
The “New” ABCs Admit Begin CT
scan
Examine pt only if CT doesn’t tell you what’s wrong – the “CT-directed physical exam”
Everybody loves CT scan…
Often times, resuscitation seems like a race to CT scan Sometimes pt’s taken to CT after barely completing primary survey, let alone the secondary portion
Death begins in X-ray
True Case
Young year old man
Restrained passenger Side impact on his side Intubated in field (mental status) ? Right chest crepitance
Being wheeled to CT scan when trauma resident stopped and insisted on reviewing CXR
Dilemma
What’s the cost of a CT scan – real $$ Versus
Cost of missed or delayed injuries Faster thru put (double-edge) Peace of mind
Can you accurately predict who needs or doesn’t need a CT scan?
Injuries distracting from IAI after blunt trauma
Prospective study, GCS 15 and CT of abdomen or DPL Presence of pain and/or tenderness
sensitivity 82% specificity 45% positive predictive value 21% negative predictive value 93%
Abdominal pain and/or tenderness higher incidence of IAI, the lack of these findings did not preclude IAI Am J Emerg Med 1998;16:145-9
CT for blunt abdominal trauma in the ED: a prospective study.
196 patients were evaluated Abdominal tenderness present in 120 22 patients had IAI (11%) Abnormal abdomen PE and hematuria
sensitivity of 64% specificity of 94% positive predictive value of 56% negative predictive value of 95%
Am J Emerg Med 1998;16:338-42
Absence of IAI predicted with sensitivity 100% & specificity 87%
Use of abdominal CT in blunt trauma: do we scan too much?
Only 37% (40 of 109) of scans were suggestive of IAI Accuracy in predicting positive scans in equivocal cases is poor Two clinical prediction rules were found in the literature Accurate retrospectively, but haven’t been used prospectively
Admit or obs is not necessary after a negative Abd CT: results of a prospective, multi-institutional trial
22 months at four Level I trauma centers All patients with blunt abdominal trauma suspected by either PE or mechanism were evaluated by protocol PE in the ED Abdominal CT scan Hospitalization for observation Standardized PE repeated 4 - 8 hrs later J Trauma 1998;44:273-80
Admit or obs is not necessary after a negative Abd CT
2299 fulfilled the entire study protocol 21% were positive 19% patients with a positive CT scan had no tenderness Negative predictive power of abd CT scan based on prelim reading and need for a laparotomy was 99.63%
Can we omit head CT??
Loss of consciousness: when to perform computed tomography?
Minor head trauma: Is computed tomography always necessary?
Kids w/ LOC or amnesia and GCS 13-15 should have a head CT to avoid missing an intracranial injury
Routine head CT in pts with LOC/amnesia but no Sx/signs of depressed skull fracture has minimal value and not warranted
NEXUS
Value of repeat cranial CT in patients with minimal head injury
MHI and a positive cranial CAT scan 151 had a persistently normal or improved neurological examination none required after the repeat cranial CAT scan ? Value repeat CAT scan in this setting
J Trauma 2004;56:475-80
Do we really need CT in primary evaluation of blunt chest trauma in patients with "normal" CXR?
93 consecutive patients
76% MVC > 10 mph 24% after fall > 5 ft
25 had normal CXR and 13 (52%) CT scan showed multiple injuries
Reevaluation of diagnostic procedures for transmediastinal gunshot wounds
22 stable patients CT scans were positive in 7 Directed further diagnostic evaluation – 2 operations 68% had negative CT scans and were observed without further evaluation No missed injuries Hospital charges generated with CT-based protocol were significantly less J Trauma 2002;53:635-8
Reformatted visceral protocol HCT vs. conventional radiographs of T and L spine in blunt trauma patients
prospective evaluation of consecutive patients with thoracic and lumbar spine fractures Screening sensitivity
Reformatted HCT: 97% (T) and 95% (L) Conventional Xray:62% (T) and 86% (L)
J Trauma 2003;55:665-9
It’s always good to exam the patients…
Restrained rear seat passenger with seatbelt, c/o some abd pain
Reliability of clinical exam in detecting pelvic fx in blunt trauma
12 studies with 5454 patients 49 false neg cases fx
majority had either altered consciousness or minor pelvic fracture only
Only 3 clinically relevant pelvic fractures were missed among 441 pts with fracture within a total population > 5000 In stable and alert trauma pts, thorough exam will detect pelvic fractures with nearly 100% sensitivity
Selective management of penetrating neck trauma based on level of injury
312 pts over 18 years
75% stab, 25% GSW Zone I=13%, Zone II=67%, Zone III=20%
34% early exploration (16% nontherapeutic) 66% observed (0.5% delayed exploration)
Am J Surg 1997;174:678-82
Selective Management Unstable Hard signs Penetrating Neck Injury
Symptoms or Signs
OR Zone I
study
Zone II
OR
Zone III
angio
Zone I
study
Asymptomatic Zone II/III
observe
You can’t get it back in…
“Pan Scan”
CT of the head, cervical spine, chest, abdomen, and pelvis, with the following inclusion criteria: (1) no visible evidence of chest or abdominal injury (2) hemodynamically stable (3) normal abdominal examination results in a neurologically intact patient or unevaluable abdominal examination results secondary to a depressed LOC, and (4) significant mechanisms of injury
Main Outcome Measure
Any alteration in the normal treatment plan as a direct result of CT scan findings. Included:
Early hospital discharge Admission for observation Operative intervention Additional diagnostic studies or interventions
Results:
1000 patients underwent pan scan during the 18-months 592 were evaluable patients with no obvious signs of abdominal injury Clinically significant abnormalities were found in
3.5% of head CTs 5.1% of cervical spine CTs 19.6% of chest CTs 7.1% of abdominal CTs
Overall treatment was changed in 19% of patients based on abnormal CT scan findings
Pan Scan We believe that a liberal policy of CT scanning is warranted in patients with blunt multisystem trauma, even among select patients without obvious signs of injury. Although the overall incidence of significant injuries identified by the pan scan was low among evaluable patients, it did prompt immediate intervention in several potentially life-threatening injuries. Of equal or greater importance is the value of a normal pan scan in reliably excluding significant injuries and allowing for earlier discharge or disposition of patients.
Not an either/or question
CT scan technology will continue to improve
Faster More accurate Supplanting other invasive modalities
CT is complimentary to good initial assessment and serial examinations