Secondary ultrasound examination increases the sensitivity of the FAST exam in blunt trauma.
BACKGROUND
Approximately one third of stable patients with significant intra-abdominal injury do not have significant intraperitoneal blood evident on admission. We hypothesized that a delayed, repeat ultrasound study (Secondary Ultrasound--SUS) will reveal additional intra-abdominal injuries and hemoperitoneum.


METHODS
We performed a prospective observational study of trauma patients at our Level I trauma center from April 2003 to December 2003. Patients underwent an initial ultrasound (US), followed by a SUS examination within 24 hours of admission. Patients not eligible for a SUS because of early discharge, operative intervention or death were excluded. All US and SUS exams were performed and evaluated by surgical/emergency medicine house staff or surgical attendings.


RESULTS
Five hundred forty-seven patients had both an initial US and a SUS examination. The sensitivity of the initial US in this patient population was 31.1% and increased to 72.1% on SUS (p < 0.001) for intra-abdominal injury or intra-abdominal fluid. The specificity for the initial US was 99.8% and 99.8% for SUS. The negative predictive value was 92.0% for the initial US and increased to 96.6% for SUS (p = 0.002). The accuracy of the initial ultrasound was 92.1% and increased to 96.7% on the SUS (p < 0.002). No patient with a negative SUS after 4 hours developed clinically significant hemoperitoneum.


CONCLUSIONS
A secondary ultrasound of the abdomen significantly increases the sensitivity of ultrasound to detect intra-abdominal injury.
Blackbourne
Lorne H
LH
United States Army Institute of Surgical Research, San Antonio, Texas, USA.
Soffer
Dror
D
McKenney
Mark
M
Amortegui
Jose
J
Schulman
Carl I
CI
Crookes
Bruce
B
Habib
Fahim
F
Benjamin
Robert
R
Lopez
Peter P
PP
Namias
Nicholas
N
Lynn
Mauricio
M
Cohn
Stephen M
SM
D000005:Abdomen / Q000000981:diagnostic imaging* / Q000601:surgery; D000007:Abdominal Injuries / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D005431:Florida; D006465:Hemoperitoneum / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery; D006785:Hospitals, University; D006801:Humans; D007223:Infant; D007813:Laparotomy; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors; D014193:Trauma Centers; D014463:Ultrasonography; D014949:Wounds, Nonpenetrating / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery