Free fluid on CT - what next?
Alex Ng
Associate Director, Trauma Service
Outline
Free Fluid on CT
What next?
Alexander Ng FRACS
Trauma Service
Auckland City Hospital
Free Fluid on CT – what next?
Case studies
Definition
The management dilemma
The evidence
Suggested approach
Case 1
35F
Restrained front seat passenger, single vehicle rollover
30 minute extrication
Emergency Room
10 survey
A: protecting
B: spontaneous, RR 16
C: P 90, BP 105
D: GCS 14 (E3 V5 M6)
20 survey
chest pain
abdominal pain
left arm deformity
CT abdomen
Management options
Non-operative management
Serial physical examinations
Serial blood tests
Operative management
Timing
Operative findings
Case 2
35F
Restrained rear seat passenger, vehicle rear-ended on motorway
Emergency Room
10 survey
A: potential compromise → intubated
B: spontaneous, RR 18
C: P 115, BP 125
D: GCS 9 (E2 V2 M5)
20 survey
Head injury
Pelvic crepitus
Pelvis x-ray
CT abdomen
Management options
Non-operative management
Serial physical examinations
Serial blood tests
Operative management
Timing
Hospital course
Admitted ICU
Good initial improvement
Fever, abdominal distension, tenderness day 3
Chest clear
Laparotomy
Operative findings
Liver laceration confirmed
Single perforation in the terminal ileum
Contained enteric spillage
Primary repair of perforation, lavage
Postoperative course
Multiple episodes of sepsis from delayed leak, abscesses, fistula
Open abdomen
VAC dressings
Eventual skin graft
40 ICU days
38 ward days
“Free Fluid on CT”
Focused Definition:
Mechanism: blunt abdominal trauma
Haemodynamically stable
Free intra-abdominal fluid
No identifiable solid organ injury
Fluid not from DPL
Isolated intra-abdominal free fluid
Management dilemma
What is the significance of the fluid?
Is there direct or indirect hollow viscus injury?
Does the patient require laparotomy?
A ‘relatively new’ problem
Increasing use of CT in stable trauma patients
Non-operative management of solid organ injuries the current standard of care
Relatively poor sensitivity of CT for hollow viscus injuries
Isolated free fluid: sources
Missed solid organ injury: liver or spleen
Bleeding from mesenteric injury
Bowel injury (perforation)
Extravasation of fluid from retroperitoneal injury (pelvic fracture)
‘Physiological’ in young females
How much free fluid?
CT can accurately quantify fluid amount
Can be classified into one of 3 groups:
Trace amount: ≤ 3 CT sections
Moderate amount: 4-5 CT sections, 2 trace collections
Large amount: >5 CT sections, multiple collections
Levine et al. AJR 1995;164:1381
AAST Survey Brownstein et al, J Trauma 2000
AAST membership: trauma surgeons
Hypothetical case:
Stable, head-injured patient
Free fluid, no solid organ injury on abdominal CT
What next?
AAST Survey Brownstein et al, J Trauma 2000
Of 328 respondents
DPL 42%
Observe 28%
Laparotomy 16%
Repeat CT 12%
Review of 51 articles since 1990
10 articles suitable for analysis
Level 1 trauma centre
30 month review of BAT
All patients screened with FAST
Haemodynamically stable patients with positive FAST studied
Subsequent CT abdomen
Results
Total patients = 1367
Positive FAST = 134
Stable = 116
Solid organ injury = 88
Isolated free fluid = 28 (2%)
Isolated free fluid: management
Associated injuries
Seat belt bruising: 10 patients
Moderate / large amount of fluid: 8
Laparotomy: 10
Injury: 10
Bowel injury: 7
Therapeutic procedure: 9
Associated injuries
Chance #, flexion-distraction: 5 patients
Moderate / large amount of fluid: 5
Laparotomy: 5
Injury: 5
Bowel injury: 5
Therapeutic procedure: 5
Seat belt and flexion-distraction
Associated injuries
Pelvic fracture: 9 patients
Unstable fractures 6
Moderate / large amount of fluid: 6
Laparotomy: 7
Injury: 7
Bowel injury: 5
Therapeutic procedure: 5
Are there other clues on the CT?
Clinically significant hollow viscus injury may be associated with other signs on CT
CT signs
Bowel injury: diagnostic signs
Pneumoperitoneum
Leakage of oral contrast
Intramural gas
Intramesenteric gas
Retroperitoneal air
CT signs
Bowel injury: suspicious
Focal bowel wall thickening
Mesenteric stranding, haematoma adjacent to bowel loops
but
can be subtle, variable and observer-dependent
CT signs
Mesenteric injury
Stranding
Haematoma, free fluid between mesenteric folds
Arterial contrast extravasation
can be subtle, variable and observer-dependent
Associated injuries
Injuries with high association with intra-abdominal hollow viscus trauma
Chance fractures/flexion distraction injuries
Usually seat-belt related
Injuries commonly associated with intra-abdominal free fluid
Pelvic fractures
Other modalities to determine need for laparotomy
Diagnostic peritoneal lavage (DPL)
30+ year track record
Very (too) sensitive for blood
Can detect inflammatory response to bowel injury
White cells
Amylase
Alkaline phosphatase
DPL and isolated free fluid
Not yet proven reliable in this group
Perform in delayed fashion (>3 hours)
Measure lavage WBC (>500/mm3)
Consider cell count ratio (Fang et al)
Management of patients with isolated free fluid
Clinical findings
Radiologist review
Exclude solid organ injuries
Quantify the fluid
Trace/moderate/large
Associated injuries/patterns
Seat belt, flexion/distraction, pelvic fracture
Management of patients with isolated free fluid
Trace fluid and
No clinical signs, patient alert
Pelvic fracture
Non-operative management
Altered mental status/ventilated
Consider delayed DPL
Management of patients with isolated free fluid
Moderate or large amount of free fluid
strong recommendation for laparotomy
Especially if associated
seat belt bruising
Chance fracture/flexion-distraction injury
Unstable pelvic fracture
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Ministry of Health
