Resuscitation room ultrasound examination in the resuscitation room is rapidly replacing diagnostic peritoneal lavage as a means to evaluate the abdomen in trauma patients. The FAST (Focused Abdmonial Sonography for Trauma) scan specifically looks only for free intraperitoneal (and pericardial) fluid using five areas for ultrasound analysis. Rozycki GS; Shackford SR 'Ultrasound, what every trauma surgeon should know' J Trauma 1996 40(1):1-4 'Ultrasonography has been shown to be as accurate as DPL and CT in the detection of hemoperitoneum following abdominal trauma.'

' It is now well established that surgeons can perform a focused abdominal ultrasound for trauma (FAST) as accurately as formally trained radiologists. In a collected series of 4,941 patients, surgeons performed FAST with a sensitivity of 93.4%, a specificity of 98.7% and an accuracy of 97.5% in detecting both hemoperitoneum and visceral injury.'

FAST demonstration videos:
Courtesy Grace Rozycki, MD FACS

• Right upper quadrant
• Left upper quadrant
• Pelvis

Evidence

Level I

Level IIb

Boulanger BR; McLellan BA; Brenneman FD; Ochoa J; Kirkpatrick AW 'Prospective evidence of the superiority of a sonography-based algorithm in the assessment of blunt abdominal injury.' J Trauma, 1999 Oct, 47:4, 632-7

BACKGROUND: Although the routine use of FAST (focused assessment with sonography for trauma) in the evaluation of trauma victims is increasing, to our knowledge, a prospective comparison of contemporary adult trauma victims managed with and without FAST has not been reported in North America. METHODS: Adult victims of blunt trauma for whom there was a suspicion of abdominal injury were managed with one of two diagnostic algorithms, FAST or no-FAST. The two algorithms were compared for diagnostic accuracy, cost, time, and delayed diagnoses. RESULTS: Among 706 patients (mean Injury Severity Score, 23), 460 were managed with FAST and 246 with no-FAST. The two groups were similar with respect to age, Injury Severity Score, prehospital time, and mortality (p = not significant). There were 3 of 460 (0.7%) delayed diagnoses in the FAST group and 4 of 246 (1.6%) in the no-FAST group (p = not significant). The diagnostic accuracy for the FAST and no-FAST algorithms was 99% and 98%, respectfully. The FAST and no-FAST algorithms led to similar rates of laparotomy, 13% and 14%, respectfully, but nonoperative management was more common in the no-FAST group (p < 0.01). The mean diagnostic cost for the FAST algorithm was $156, compared with $540 with the no-FAST algorithm (p < 0.0001) and the mean time required for diagnostic work-up was 53 minutes with the FAST algorithm, compared with 151 minutes with the no-FAST algorithm (p < 0.0001). CONCLUSION: This study has provided prospective evidence that a FAST-based algorithm for blunt abdominal injury was more rapid, less expensive, and as accurate as an algorithm that used computed tomography or diagnostic peritoneal lavage only. Trauma centers are encouraged to incorporate a FAST-based algorithm into their initial management of blunt trauma victims.

Level III

Ballard RB, Rozycki GS, Newman PG, Cubillos JE, et al. (1999). “An algorithm to reduce the incidence of false-negative FAST examinations in patients at high risk for occult injury. Focused Assessment for the Sonographic Examination of the Trauma patient.” J Am Coll Surg 189(2): 145-150; discussion 150-141.

BACKGROUND: The Focused Assessment for the Sonographic Examination of the Trauma patient (FAST) sequentially surveys for the presence or absence of blood in dependent abdominal regions including the right upper quadrant, left upper quadrant, and the pelvis. But it does not readily identify intraparenchymal or retroperitoneal injuries, and a CT scan of the abdomen may be needed to reduce the incidence of missed injuries. We hypothesized that select patients who are considered high risk for occult injuries should undergo a CT scan of the abdomen when the FAST is negative so that occult injuries can be detected. STUDY DESIGN: An algorithm was prospectively tested for the evaluation of select injured patients over a 3 1/2-year period. Entrance criteria included adult patients with a blunt mechanism of trauma, a negative FAST examination, and a spine fracture (with or without cord injury), or a pelvic fracture. Trauma team members performed the FAST on patients during the Advanced Trauma Life Support secondary survey. Data recorded included the patient's mechanism and type of injury, the results of the FAST and CT scan examinations, operative or postmortem findings or both, and patient outcomes. Patients with spine injuries were grouped according to spine level and the presence or absence of neurologic deficit. The patients with pelvic fractures were grouped according to the Young and Resnick classification. RESULTS: One hundred two of 1,490 patients (6.8%) who had FAST examinations were entered into this study. Thirty-two patients (30.5% ) had spine injuries, with only one false-negative ultrasound result. Seventy patients (68.6%) had pelvic fractures with 13 false-negative ultrasound results: 11 ring (9 from motor vehicle crashes, 2 from pedestrians struck), 1 acetabular, and 1 isolated pelvic fracture. Nine patients underwent nonoperative management for solid organ injuries, and 4 patients needed surgery. CONCLUSIONS: Based on these preliminary data, we conclude that patients with pelvic ring-type fractures should have CT scans of the abdomen because of the higher yield for occult injuries.

Rozycki GS, Ochsner MG, Feliciano DV, Thomas B, et al. (1998). “Early detection of hemoperitoneum by ultrasound examination of the right upper quadrant: a multicenter study.” J Trauma 45(5): 878-883.

BACKGROUND: The focused assessment for the sonographic examination of the trauma patient (FAST) is a rapid diagnostic test that sequentially surveys for hemopericardium and then the right upper quadrant (RUQ), left upper quadrant (LUQ), and pelvis for hemoperitoneum in patients with potential truncal injuries. The sequence of the abdominal part of the examination, however, has yet to be validated. The objectives of this multicenter study were as follows: ( 1) to determine where hemoperitoneum is most frequently identified on positive FAST examinations; and (2) to determine if a relationship exists between that areas and the organs injured. METHODS: Ultrasound registries from four Level I trauma centers identified patients who had true-positive FAST examinations. Demographic data, areas positive on the FAST, and organs injured were recorded; injuries were classified as multiple, single solid organ (liver or spleen) , isolated hollow viscus, or retroperitoneal. Relationships between positive locations on the FAST examinations and the associations of organs injured to areas positive were assessed using McNamara's chi2 test; a p value < 0.05 was considered statistically significant. RESULTS: The RUQ was the most common site where hemoperitoneum was detected, and this was statistically significant compared with either the LUQ or the pelvis. Also, statistically significant correlations (p < 0.001) were observed between positive RUQ areas on the FAST and multiple injuries, single solid organ (liver or spleen) injury, and retroperitoneal injuries. CONCLUSION: Blood is most often found on the FAST in the RUQ area in patients with multiple intraperitoneal injuries or isolated injury to the liver, spleen, or retroperitoneum, but not when there is injury to a hollow viscus.

Paajanen H, Lahti P and Nordback I (1999). “Sensitivity of transabdominal ultrasonography in detection of intraperitoneal fluid in humans.” Eur Radiol 9(7): 1423-1425.

The sensitivity and specificity of ultrasonography in detection of free intraperitoneal fluid is over 90 %. The lowest detectable volume of free fluid in humans is unknown. The distribution of intraperitoneal fluid was studied in 86 patients by transabdominal US in group A (n = 21, 10 ml of fluid), in group B (n = 15, 50 ml of fluid) and group C (n = 50, splenic trauma). Ultrasound detected fluid in 15 of 21 patients in group A, and in all patients in groups B and C. In group A 10 ml of fluid was found in 71 % of cases behind the bladder, and in only 5-14 % of cases in the upper abdomen. In group B 50 ml of fluid was found in all patients in the lower pelvis, but in only 20 % in Morison's pouch and in 7 % around the spleen. In group C 200-4500 ml of fluid was detected by US in 72 % of patients in the perisplenic space, in 60 % in Morison's pouch and in 42 % in the retrovesical space. Small volumes of free intraperitoneal fluid (10-50 ml) can be detected with current US scanners, but only near the site of injury. These results support the role of US as a primary imaging modality in abdominal trauma.

Bain IM; Kirby RM; Tiwari P; McCaig J; Cook AL; Oakley PA; Templeton J; Braithwaite M 'Survey of abdominal ultrasound and diagnostic peritoneal lavage for suspected intra-abdominal injury following blunt trauma.' Injury, 1998 Jan, 29:1, 65-71

Over a 3 year period all severely injured blunt trauma patients who were investigated with abdominal ultrasound examinations (AUS) or diagnostic peritoneal lavage (DPL) to exclude intra-abdominal injury were evaluated. The ultrasound examinations were performed by radiologists in 220 severely injured patients (20 of whom also had DPL). The overall sensitivity and specificity of abdominal ultrasound were 82.7% and 99.5%, respectively. The sensitivity increased to 89.1% by repeat scanning. In comparison, 72 DPLs were performed in severely injured patients; the overall sensitivity and specificity of DPL were 82.8% and 97.2%, respectively. DPL resulted in more non-therapeutic laparotomies, 9/25 (36%) compared with 3/23 (13%) with AUS. Abdominal ultrasound is now the first line investigation at this centre for evaluation of possible intra-abdominal injury in injured patients.

Guide to Evidence Appraisals

The definitions of the types of evidence and the grading of recommendations used originate from the US Agency for Health Care Policy and Research