Emergency Medicine EBM:Emergency Medicine EBM:ED Radiological Evaluation of the Blunt Abdominal Trauma Patient*

Amy Gutman MD ~ LSH-HSC Department of Emergency Medicine

prehospitalmd@gmail.com

*Subtitle: *Subtitle: Fostering critical

thinking skills

OVERVIEWOVERVIEW

• Case Study

• Four Questions:

– Why Only Radiology Residents Performing “Official” FAST Exam?

– Why FAST if Everyone Gets A CT?

– Why PO Contrast For The Abdominal-Pelvic CT?

– What Is the Utility (?Futility) of a “Toughie” Scan In Patients With Isolated Injuries Not Directly Involving the Abdominal-Pelvic Area?

• Conclusions

FOR FUN…FOR FUN…

CASE STUDYCASE STUDY

•25 yo WM “trauma stat” post receiving a GSW to non-dominant LUE

•Drove self to hospital (restrained driver), “jumping” curb at ED ambulance entrance at speed <10 mph

•GCS 15, SBP 98, pulseless LUE. No visible signs of injury on secondary survey, including (-) FAST SCAN by ED resident

•Repeat SBP > 120 with properly fitting cuff. Pt remained HD stable throughout initial evaluation, complaining only of pain at GSW site

WHAT WOULD YOU DO?WHAT WOULD YOU DO?

US Army Historical Documents

For Wolcott

WHAT WAS DONEWHAT WAS DONE

• Lateral C-Spine• Portable CXR• Portable Pelvis• Portable LUE• CT Head• CT C-Spine• CT Chest with IV Contrast• CT Abdomen/ Pelvis with PO/IV Contrast• CT Angiogiography LUE

RESULTSRESULTS

• LUE Plain Films: – No bony fracture, + tracking air sub q with soft tissue

swelling. No foreign bodies

• LUE Angiography: – Negative

• Every Other Freakin’ Radiologic Study: – Negative

• Cost To Patient (i.e. “Us”)– > $6,500 for studies alone– Does not take into account radiology reading fee,

angiography suite costs, film costs, etc

BLUNT BLUNT ABDOMINAL ABDOMINAL TRAUMA (BAT)TRAUMA (BAT)

• “Blunt”: non-penetrating injury

• Trauma involving area between the nipples & distal ischium

• May include “thoracic” area, buttocks, rectum, GU systems

MECHANISM OF INJURYMECHANISM OF INJURY

• Rapid deceleration, usually due to falls or MVCs

• Noncompliant/ “solid” organs high risk of parenchymal fracture

• Duodenum & urinary bladder susceptible hollow organs

• Decreased head, chest & solid organ injuries (seatbelts/ airbags), greater pancreatic, mesenteric, & intestinal injuries (compression against spinal column)

• Death results principally from hemorrhage or sepsis

WHY ARE ONLY WHY ARE ONLY RADIOLOGY RADIOLOGY RESIDENTS RESIDENTS

ALLOWED TO ALLOWED TO PERFORM THE PERFORM THE

”OFFICIAL” FAST ”OFFICIAL” FAST EXAMINATION? EXAMINATION?

WHAT IS A “FAST” AND WHY SHOULD WHAT IS A “FAST” AND WHY SHOULD IT BE IMPORTANT ANYWAY?IT BE IMPORTANT ANYWAY?

• “Focused Assessment with Sonography for Trauma”

• Limited US directed at identifying free intraperitoneal or pericardial fluid

• In traumatic injury, free fluid usually due to hemorrhage, contributing to circulation assessment

• 30-70cc free fluid minimum amount of fluid visible to trained clinician, 1st noted in Morrison’s Pouch

Schwartz; Surgery, 1999

Trauma.org

Scalea TM. Focused assessment with sonography for trauma (FAST): results from an international consensus conference, J Trauma 46:466, 1999

Branney SW et al: Ultrasound based key clinical pathway reduces the use of hospital resources for the evaluation of blunt abdominal trauma, J Trauma 42:1086, 1997

• Recent studies emphasize FAST performed by surgeons or EM Physicians

• Amount of training & experience varies widely in studies, with credentialing a topic of debate

• Conflicts developed over who should perform emergency ultrasonography*

• The requisites of the sonographer are competency, present during acute phase of resuscitation, & can perform serial scans

• Competency requires credentialing. The learning curve for FAST exam is steep; most are competent after 25 scans

• Credentialing includes formal instruction on principles & physics of US, skills stations, practice exams for negative & positive FASTs, & proctoring on ultrasound trauma resuscitations

*Trauma.org

WHY EVEN WHY EVEN PERFORM A PERFORM A

FAST EXAM IF FAST EXAM IF EVERY GETS A EVERY GETS A CT ANYWAYS? CT ANYWAYS?

Sabiston’s/ Current Surgical*: Comparison of Diagnostic Methods for Blunt Abdominal Trauma (*modified from both sources)

Methods Time Cost Advantages/Disadvantages

Physical Exam Quick $ Serial exams, limited by distracting injuries, coma, drug intoxication, poor sensitivity/ specificity

DPL Quick $$ Rapid results, but invasive. Overly sensitive for blood, not specific for site of injury; requires experience; limited if previous surgery

FAST Quick $ Rapid detection of intra-abdominal fluid, cardiac tamponade, limited by operator, body habitus,

subQ air, poor for detection of bowel injury. Fairly sensitive but not highly specific

Helical CT Slower $$$$ Specific for injury site, evaluation of RP. Good sensitivity, risk of reaction to contrast dye

Trauma.org: Comparison of Emergency Radiology Diagnostic Modalities

US CT DPL

Rapid ++  + +Portable ++  - +Non-invasive ++ ++  -Ease of Use ++  - +Sensitivity   ++ ++ ++Specificity + ++  - Eval of RP  - ++ - Eval of pericardium ++ ++  -Interpretation Ease +  ++ +Ease of Repetition ++ +  -Radiation Exposure +  ++ -Patient Acceptance + ++  -Cost + ++ ++

Trauma.org: Ultrasound Vs. CT in Detecting Solid Organ InjuryTrauma.org: Ultrasound Vs. CT in Detecting Solid Organ Injury

Study N Sensitivity(%) Specificity(%) NPV(%)

Ballard et al,1999 102 28 99 85Boulanger et al,1996 400 81 97 96Chiu et al, 1997 772 71 100 98Coley et al, 2000 107 38 97 78Hoffmann et al, 1992 291 89 97 93Ingeman et al, 1996 97 75 96 92Kern et al, 19975 18 73 98 98Liu et al, 1993 55 92 95 84McElveen et al, 1997 82 88 98 96McKenney et al, 1996 996 88 99 98Rozycki et al, 1993 470 79 96 95Rozycki et al, 1995 365 90 100 98Rozycki et al, 1998 1227 78 100 99Shackford et al, 1999 234 69 98 92Thomas et al, 1997 300 81 99 98Tso et al, 1992 163 69 99 96Wherret et al, 1996 69 85 90 93Yeo et al, 1999 38 67 97 93Total 6324 75 98 94

Bakker J, Genders R. Sonography as the primary screening method in evaluating blunt abdominal trauma. J Clin Ultrasound. 2005 May;33(4):155-63

• PURPOSE: radiological evaluation of BAT patients can be done with either US or CT with strategies varying among institutions

• METHODS: retrospective analysis of all patients with possible BAT who underwent abdominal US, abdominal CT and/or a laparotomy

• RESULTS: 961/ 1149 patients had negative US; 922 “true” negative, (96% negative predictive). CT performed in 7%. In 2% there was delayed diagnosis with no significant morbidity. 14% laparotomies non-therapeutic; in 5 of these cases patients underwent non-therapeutic laparotomy despite negative CT

• CONCLUSIONS: US for evaluation of acute BAT is adequate, with a high negative predictive value, a small number of delayed diagnoses, & an acceptable rate of non-therapeutic laparotomies

Brown MA, Casola G. Blunt abdominal trauma: screening in 2,3693 patients. Radiology. 2001 Feb;218(2):352-8

• PURPOSE: Evaluate accuracy of screening abdominal US in patients with BAT

• MATERIALS AND METHODS: Patients with BAT underwent US. US positive if free fluid or parenchymal abnormalities consistent with trauma detected. US results compared with findings of DPL, repeat US, CT, cystography, surgery, &/ or autopsy and/or the clinical course

• RESULTS: 2,693 US exams. Positive in 145/ 172 patients with injuries who underwent surgical repair of injuries. False-negative findings were RP injury, bowel injury, & intraperitoneal solid organ injury w/o hemoperitoneum. No patient with false-negative findings died. Specificity of US 96%, overall accuracy 96% Positive predictive value 61%, & negative predictive value 9%

• CONCLUSION: Abdominal US useful in screening for BAT injury. Its use represents a change in institutional practice. CT used when screening US findings positive, when injury clinically suspected despite negative US findings, or when US not available

Blackborne LH, et al. Secondary ultrasound examination increases the sensitivity of the FAST exam in blunt trauma. J Trauma. 2004 Nov;57(5):934-8

• INTRODUCTION: 1/3 stable pts with significant intra-abdominal injury do not have intraperitoneal blood evident on admission. Study if delayed, repeat US reveals additional intra-abdominal injuries/ hemoperitoneum

• METHODS: Prospective observational. Patients underwent initial US, followed by repeat exam w/i 24 hours. All exams performed & evaluated by surgical/ EM house staff or attendings

• RESULTS: 547 pts had both initial & repeat exam. Sensitivity of initial US 31.1%, increasing to 72.1% on repeat (p < 0.001) for intra-abdominal injury or intra-abdominal fluid. Specificity for initial US 99.8% & 99.8% for repeat exam. Negative predictive value 92.0% for initial US increasing to 96.6% for repeat (p = 0.002). Accuracy of initial ultrasound 92.1% increasing to 96.7% on repeat exam (p < 0.002). No patient with a negative SUS after 4 hours developed clinically significant hemoperitoneum

• CONCLUSION: Secondary abdominal ultrasound significantly increases sensitivity of ultrasound to detect intra-abdominal injury.

• In Aug 2006, LSU-HSC Department of Radiology expected to present findings of an institutional, retrospective review of positive & negative “Whole Body” Trauma CT scans done

• The goal is determining the positive & negative predictive value of each scan, as well as the cost to patient, cost to institution, and “lives saved”

– How many negative scans to find the 1 patient whose outcome changed secondary to that intervention alone?

WHY DOES WHY DOES EVERYONE GET EVERYONE GET CONTRAST FOR CONTRAST FOR

THEIR THEIR ABDOMINAL-ABDOMINAL-

PELVIC CT SCAN?PELVIC CT SCAN?

Shreve W et al: Retrospective analysis of the adequacy of oral contrast material for computed tomography scans in trauma patients, Am J Surg 178:14, 1999

Clancy T et al: Oral contrast is not necessary in the evaluation of blunt abdominal trauma by computed tomography, Am J Surg 166:680, 1993

• PURPOSE: Utility of oral contrast in abdominal CT questionable.

• Proponents argue that oral contrast safe, aids in delineation of small bowel & pancreatic injuries

• Opponents contend oral contrast fails to reach the small bowel in reasonable time, administration delays CT scan, induces vomiting/ aspiration in 10 - 23% of patients, & does not increase visualization of solid visceral injury

Clancy TV, Ragozzino MW, Ramshaw D. Oral contrast is not necessary in the evaluation of blunt abdominal trauma by computed tomography. Am J Surg. 1993 Dec;166(6):680-4

• BACKROUND: are routine abdominal CT scans performed w/o OC associated with diagnostic error in patients with blunt trauma

• METHODS: 492 patients had CT scans for the evaluation of BAT

• RESULTS: 76% CT scans negative, 24% positive. OC used in 8/ 492 (1.6%). 1/ 372 whose initial non-OC-enhanced scan negative subsequently required surgery. 5 bowel injuries among 42 patients who underwent abdominal surgery; in none would the use of OC ensured the preoperative diagnosis

• CONCLUSION: Omission of OC did not represent a disadvantage to BAT patients undergoing routine abdominal CT. Potential time delays & hazards associated with use of OC were minimized

Stuhlfaut JW, Soto JA, Lucey BC, et al. Blunt abdominal trauma: performance of CT without oral contrast material. Radiology. 2004 Dec;233(3):689-94

• PURPOSE: Retrospectively evaluate CT w/o OC to identify bowel & mesenteric injuries requiring surgical repair in BAT patients

• MATERIALS AND METHODS: 1082 pts had CT w/o OC. Findings: negative, solid organ injury +/- hemoperitoneum, free fluid only, & suspected bowel or mesenteric injury. Sensitivity, specificity, positive & negative predictive calculated by comparing CT findings OR reports

• RESULTS: No injury (932), solid organ injury (102), free fluid (34), suspected bowel or mesenteric injury (14). 1066 true-negative, 9 true-positive, 2 false-negative, 5 false-positives. Sensitivity 82%, specificity 99%, positive predictive value 64%, & negative predictive value 99% for identifying bowel & mesenteric injuries

• CONCLUSION: CT without OC adequate for depiction of bowel & mesenteric injuries requiring surgical repair. Results comparable with previously reported data for single-row helical CT with oral contrast

Allen TL, et al. Computed tomographic scanning without oral contrast solution for blunt bowel and mesenteric injuries in abdominal trauma. J Trauma. 2004

Feb;56(2):314-22

• BACKGROUND: CT with IV & OC advocated for evaluation of intra-abdominal injury, including blunt bowel & mesenteric injuries (BBMIs). Necessity of OC in detecting these injuries questioned. Purpose of this study to determine sensitivity & specificity of CT scanning without OC for BBMIs

• METHODS: Prospective. 500 consecutive blunt trauma pts receiving abdominal CT imaging. All imaged without OC, but with IV contrast. CT images reviewed by a research radiologist blinded to initial CT read

• RESULTS: Initial CT reading detected 19/ 20 BBMIs. Initial CT read missed 1 duodenal perforation. 2 with false-positive interpretations. Sensitivity & specificity of CT imaging for detection of BBMIs were 95.0% & 99.6%, respectively

• CONCLUSION: Abdominal CT imaging without OC for detection of BBMIs compares favorably with CT imaging using oral contrast

Stafford RE, McGonigal MD, Weigelt JA, Johnson TJ. Oral contrast solution and computed tomography for blunt abdominal trauma: a randomized study. Arch Surg. 1999 Jun;134(6):622-6

• HYPOTHESIS: Determine if OC necessary in acute CT evaluation of BAT

• DESIGN: Randomized controlled. 394 pts randomized to receive/ not receive OC after placement of NGT. All received IV contrast

• OUTCOME MEASURES: Abn CT, laparotomy, missed GIT/ solid organ injuries, NV

• RESULTS: 199 OC, 195 no OC. 50 OC, 55 no OC abnormal exams; 33 pts with abnormal scans (19 OC, 14 no OC) underwent laparotomy. 1 nontherapeutic laparotomy in each group. 1 missed small-bowel injury in OC, no missed small-bowel injuries in no OC. 6 bowel injuries identified at laparotomy in OC. 3 bowel injuries identified in the no OC. Specificity for solid organ injury was 94% in OC & 57.1% in no OC. Sensitivity for solid organ injury was 84.2% in OC & 88.9% in no OC. Average time to abd CT scanning was 39.02+/-18.73 minutes in no OC group and 45.92+/-24.17 minutes in OC group (P= .008).

• CONCLUSION: Addition of OC to CT protocol for the evaluation of the patient with blunt abdominal trauma is unnecessary and delays time to CT scanning

WHAT IS THE UTILITY/ FUTILITY OF WHAT IS THE UTILITY/ FUTILITY OF A “TOUGHIE” SCAN IN PATIENTS A “TOUGHIE” SCAN IN PATIENTS WITH ISOLATED INJURIES NOT WITH ISOLATED INJURIES NOT

DIRECTLY INVOLVING THE DIRECTLY INVOLVING THE ABDOMINAL-PELVIC AREA? ABDOMINAL-PELVIC AREA?

Baby Springhart

Linsenmaier U, et al. Structured radiologic diagnosis in polytrauma Radiologe. 2002 Jul;42(7):533-40

• PURPOSE: Development of structured diagnostic imaging in pts with multiple trauma

• METHODS: Prospective. 2400 patients with multiple trauma. All diagnostic & therapeutic steps, primary & secondary death & 90 day lethality documented

• RESULTS: Criteria for initiation of a shock room treatment, strategies for documentation & interdisciplinary algorithms for the early clinical care coordinating diagnostic imaging & therapeutic procedures following standardized guidelines. Diagnostic imaging consists of basic diagnosis, radiological ABC, radiological follow-up & structured organ diagnosis using CT. Radiological trauma scoring allows improved quality control of diagnosis and therapy of multiple injured patients

• CONCLUSION: Structured diagnostic imaging of multi-injured pts leads to standardization of diagnosis & therapy, ensuring constant quality

Fasolo AO, Obichina AE, Arotiba JT. Concomitant injuries in 531 patients with maxillofacial fractures. Afr J Med Med Sci. 2002 Jun;31(2):101-5

• PURPOSE: 10 year review of 531 patients with facial fractures who sustained 648 associated injuries

• RESULTS: M:F = 3:1. Highest incidence was in 21-30 yr ages. MVC most common etiology; most frequently associated injury soft tissue lacerations (71.0%). Neurological injuries 10% total number of concomitant injuries. Other associated injuries seen were orthopedic 9.5%, ophthalmologic 6.6%, chest 1.9%, abdominal 0.6% & urological 0.5%

• CONCLUSION: Surgical team should be appropriately organized in the treatment of patients with concomitant injuries coexisting with maxillofacial fractures

Adili A, et al. Humeral shaft fractures as predictors of intra-abdominal injury in motor vehicle collision victims. Arch Orthop Trauma Surg. 2002 Feb;122(1):5-9

• PURPOSE: Assess utility of humeral shaft fractures as predictors of organ & skeletal injuries in multiply injured patients involved in MVCs

• METHODS: Prospective database of multiply injured motor vehicle occupants with ISS > 12 admitted to Level I trauma centre in 102-month period, reviewed to assess skeletal & organ injuries associated with a humeral shaft fracture. The effect of occupant location in vehicle, point of collision, & use of seat belt also examined to identify injury patterns

• RESULTS: 1070 pts. Patients with humeral shaft fracture had significantly greater liver injuries (p = 0.022), forearm/hand fractures (p < 0.001), tibial fractures (p < 0.01) & femoral fractures (p < 0.01) compared with controls. Lateral collision impact trended towards increased splenic & hepatic injuries in humeral shaft fracture group

• CONCLUSIONS: A humeral shaft fracture in a MVC multiply injured pt significantly associated with increased incidence of both upper & lower extremity fractures & liver injury. Humeral shaft fractures serve as a predictor of potential intra-abdominal pathology in multiply injured trauma patients involved in MVCs

Atanaijec TC, Savic SN, Nikolic SD, Djoki VM. Frequency and severity of injuries in correlation with the height of fall. J Forensic Sci. 2005 May;50(3):608-12

• PURPOSE: examine correlation between height of fall & type of injuries of certain body regions and organs

• METHODS: 660 cases of fatal falls (469 males, 191 females)

• RESULTS: frequency & extent of the injured body regions and organs are related to fall height. The height of fall over 15 m appears to be a boundary height beyond which the injuries of two or three body regions are generally associated

Lim LH, et al. Associated injuries in facial fractures: review of 839 patients. Br J Plast Surg. 1993 Dec;46(8):635-8

• PURPOSE: report incidence & nature of significant associated neurosurgical, ocular, spinal, torso & extremity injuries in facial fracture patients over 3 years

• RESULTS: Of 839 patients, 11% sustained significant concomitant injuries outside the facial skeleton. Injuries: 5% neurosurgical, 4% ocular, 1% spinal, 2% torso & 7% extremities

• CONCLUSIONS: Most neurosurgical injuries result from focal impact & intervention required related to local fracture, & management & the repair of dural tears. Risk of significant ocular injury highest when fracture involves orbit. Injuries of spine, torso & limbs most common in MVCs

Beck D, et al. Prospective study of the clinical predictors of a positive abdominal computed tomography in blunt trauma patients. J Trauma. 2004 Aug;57(2):296-300

• BACKGROUND: Many CT scans used in the evaluation of blunt trauma patients are negative. Clinical predictors of positive abdominal CT scans would be beneficial in patient care

• METHODS: Prospective study of 213 patients at a Level I trauma center presenting with blunt trauma who underwent abdominal CT scan

• RESULTS: Univariate chi2 tests showed abnormal pelvis x-ray (p = 0.0002) and an intubated patient (p = 0.03) predictors of a positive CT scan. Alcohol intoxication statistically significant predictor of a negative CT scan (p = 0.03)

• CONCLUSION: data suggest that an abnormal pelvis x-ray & intubation are significant risk factors for a positive CT scan. Alcohol intoxication, mechanism of injury, & unreliable examination, without other associated indication for a scan, may warrant further study

CONCLUSIONSCONCLUSIONS

Any trained clinician can accurately perform & interpret a FAST scan without delay required for

arrival of “specialized” personnel

Why Are Only Radiology Residents Performing “Official” FAST Exam?

Why Perform a FAST Exam if Everyone

Gets A CT?

The sequence of diagnostic tests in multiply injured patients requires sound

judgment by the trauma leader

Why Does Everyone Get PO

Contrast?

PO contrast unnecessary in vast majority of patients, delays time to the CT scanner, &

has potential harmful side effects

What Is the Utility (?Futility) of a “Whole Body” CT Scan

In Patients With Isolated Injuries Not Directly

Involving the Abdominal-Pelvic Area?

Careful evaluation of both the patient & MOI should guide diagnostic testing rather than

a “shotgun” algorithm

Per The ED Nurses’ Per The ED Nurses’ Requests…Requests…

The fourth horseman of the apocalypse is symbolic of death and devastation. Revelations 6:8, "I looked, and there before me was a pale horse! Its rider was

named Death, and Hades was following close behind him. They were given power over a fourth of the earth to kill by sword, famine and plague, and by the

wild beasts of the earth."