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Emergency Ultrasound Emergency Ultrasound in in
TraumaTrauma
Anthony J Weekes MD, RDMSAnthony J Weekes MD, RDMSJanet G. Alteveer, MDJanet G. Alteveer, MDSarah Stahmer, MD
Anthony J Weekes MD, RDMSAnthony J Weekes MD, RDMSJanet G. Alteveer, MDJanet G. Alteveer, MDSarah Stahmer, MD
Clinical CaseClinical CaseGR is a 62 y male who hit his right torso
when he slipped on an icy sidewalk. He denies head trauma, and can walk without a limp. Two hours later the pain in his lower chest has increased he comes to the ED.
Clinical CaseClinical Case
PE: BP116/72, pulse109, RR 24. There is a minor abrasion to right lateral
chest, which is tender to palpation. Diffuse mild abdominal tenderness.
Meds: Coumadin for irregular heartbeat
Clinical CaseClinical Case
2 large IV’s placed, CXR done. Blood tests sent.
Bedside ultrasound done.
CXR revealed lower rib fractures, no HTX or PTX
Clinical CaseClinical Case
FFP ordered and OR notified.
He is found to have a liver laceration and 500 cc of blood in the peritoneal cavity.
Diagnostic Modalities in Blunt Diagnostic Modalities in Blunt Abdominal TraumaAbdominal Trauma
Diagnostic Peritoneal Lavage (DPL)CAT ScanUltrasound (FAST exam)
Diagnostic Peritoneal LavageDiagnostic Peritoneal Lavage
Advantages– Very sensitive for
identifying intra-peritoneal blood
– 106 RBC/mm3 approx. 20 ml blood in 1L lavage fluid
– Can be done at the bedside
– Can be done in 10-15 minutes
Disadvantages– Overly sensitive, may
result in too high a laparotomy rate
– Invasive– Difficult in pregnancy,
or with many prior surgeries
– Can not be repeated
CT ScanCT Scan
Advantages– Identifies specific
injuries– Good for hollow viscus
and retroperitoneal injury
– High sensitivity and specificity
Disadvantages– Expensive equipment– 30-60 minutes to
complete study– Only for stable
patients– Not for pregnant
patients
FASTFAST
Advantages– Can be performed in 5
minutes at the bedside– Non-invasive– Repeat exams– Sensitivity and
specificity for free fluid equal to DPL and CT
Disadvantages– Operator dependent– May not identify
specific injury– Poor for hollow viscus
or retroperitoneal injury
– Obesity, subcutaneous air may interfere with exam
FAST PrinciplesFAST Principles Detects free
intraperitoneal fluid Blood/fluid pools in
dependent areas Pelvis
– Most dependent
Hepatorenal fossa– Most dependent area in
supramesocolic region
FAST PrinciplesFAST Principles Pelvis and Supra-
mesocolic areas communicate– Phrenicolic ligament
prevents flow
Liver/spleen injury– Represents 2/3 of cases of
blunt abdominal trauma
FAST- principlesFAST- principles
Intraperitoneal fluid may be– Blood– Preexisting ascites– Urine– Intestinal contents
FAST – limitationsFAST – limitations
US relatively insensitive for detecting traumatic abdominal organ injury
Fluid may pool at variable rates– Minimum volume for US detection– Multiple views at multiple sites– Serial exams: repeat exam if there is a change
in clinical pictureOperator dependent
Evidence supporting use of Evidence supporting use of FASTFAST
Multiple studies in USA by EM and trauma surgeons
Studies from Europe and JapanPolicy statements by specialty organizations
Emergency department ultrasound in the evaluation of blunt abdominal trauma.
Jehle, D., et al, Am J Emerg Med, 1993
– Single view of Morison’s pouch in 44 patients– Performed by physicians after 2 weeks training– US compared to DPL and laparotomy– Sensitivity 81.8%– Specificity 93.9%
Trauma surgical studyTrauma surgical study
A prospective study of surgeon-performed ultrasound as the primary adjuvant modality of injured patient assessment. 1994 Rozycki et al.
N=358 patientsOutcomes used: US detection of
hemoperitoneum/pericardial effusion
ResultsResults53/358 (15%) patients w/ free fluid on
“gold standard”All patients: Sens 81.5%, spec 99.7% Blunt trauma: Sens 78.6%, spec 100%PPV 98.1%, NPV 96.2%Overall accuracy was 96.5% for detection
of hemoperitoneum or pericardium
Trauma StudyTrauma Study
Rozycki G, et al 1998 Surgeon-performed ultrasound for the assessment of truncal injuries. Lessons learned from 1540 patients
FAST exam on patients with precordial or transthoracic wounds or blunt abdominal trauma
Protocol:+ Pericardial fluid OR
Stable CT+IP fluid
Unstable OR Results
– N= 1540 pts, 80/1540 (5%) with FF– Overall: Sens 83.3%, Spec 99.7%– PPV 95%, NPV 99%– Precordial/Transthor : Sens 100%, Spec 99.3%– Hypotensive BAT: Sens 100%, Spec 100%
FAST – Specialty SocietiesFAST – Specialty Societies
Established clinical role in Europe, Australia, Japan, Israel
German Surgical Society requires candidates’ proficiency in ultrasound
United States– US in ATLS– US policies by frontline specialties
American College of Surgeons ACEP,SAEM & AAEM
EquipmentEquipment
Curved array Various “footprints”
– Small footprint for thorax– Large for abdomen
Variable frequencies– 5.0 MHz: thin, child– 3.5 MHz: versatile– 2.0 MHz: cardiac, large
pts
Time to Complete ScanTime to Complete Scan
Each view: 30-60 secondsNumber of views dependent on clinical
question and findings on initial viewsTotal exam time usually < 3-5 minutes1988 Armenian earthquake
– 400 trauma US scans in 72 hrs
Focused Abdominal Sonography Focused Abdominal Sonography for Trauma (FAST)for Trauma (FAST)
Consists of 4 views – Subxiphoid– Right Upper
Quadrant– Left Upper
Quadrant– Pouch of Douglas
FASTFAST
Increased sensitivity with increased number of views
Will identify pleural effusions
Reliably detects as little as 50-100cc in the thorax
Sensitivity >96%, specificity 99-100%
Clinical experience with FASTClinical experience with FAST
Intraperitoneal fluid– Sensitivity 82-98%, specificity 88-100%
Morison’s pouch alone 36-82% sensitivityIncreased sensitivity with
– Increasing number of views– Trendelenberg– Serial examinations
Can detect as little as 250cc of free fluid
Clinical ExperienceClinical Experience
Solid organ disruption– 40% sensitivity for all organs– 33-94% for splenic injury
Hollow viscus injury– Sensitivity 57%
Retroperitoneal injury– Sensitivity for identification of hemorrhage
<60%
RUQRUQ
Probe at right thoraco-abdominal junction
Liver : large acoustic window
Probe marker cephalad Rib interference?
– Rotate 30° counterclockwise
RUQRUQ
Image on screen:– Liver cephalad– Kidney inferiorly– Morison’s Pouch*:
space between Glisson’s capsule and Gerota’s fascia
*
*
**
Normal RUQNormal RUQ
Image kidney – Longitudinally– Transversely
Two toned structure– Cortex/medulla– Renal sinus
Appearance of bloodAppearance of blood
Fresh blood – Anechoic (black)
Coagulating blood– First hypoechoic– Later hyperechoic
Branney, S.W. et al: Quantitative sensitivity of ultrasound in detecting free intraperitoneal fluid J Trauma:1995: 39
Peritoneal lavage fluid infused in 100 patientsSimultaneous scan of Morison’s pouch
– By physicians ( Surgery,EM, Radiology)– Blinded to volume and rate of infusion– Mean volume of detection: 619cc– Sensitivity at 1 liter: 97%– 10% physicians detected less than 400cc
Caveat to Branney study:
– Artificial condition: infused fluid– Fluid in Morison’s after pelvis overflow
Tiling et al :– 200 -250ml detected by US– Collection >0.5cm suggests over 500ml
Transvaginal/rectal– 15ml of free intraperitoneal fluid
Volume Assessment by US
Detection of Fluid by Detection of Fluid by UltrasoundUltrasound
Affected by positioning
Location of bleed Rate of bleeding Operator Experience
Value of sensitivity of Ultrasound:– Detects clinically
injuries– Non-detection of fluid
May indicate self- limited bleeding
All Fluid is not BloodAll Fluid is not Blood
AscitesRuptured Ovarian CystLavage fluidUrine from ruptured bladder
Mimics of Fluid in RUQMimics of Fluid in RUQ
Perinephric fat– May be hypoechoic like blood– Usually evenly layered along kidney– If in doubt, compare to left kidney
Abdominal inflammation– Widened extra-renal space– Echogenicity of kidney becomes more like the
liver parenchyma
PitfallsPitfalls
RUQ– Not attempting multiple probe placements– Not placing the probe cephalad enough to use the
acoustic window of the liver
Scanning too soon before enough blood has accumulated
Not repeating the scan
LUQ Scan PlaneLUQ Scan Plane
More difficult– Acoustic window
(spleen) is smaller than liver
– Mild inspiration will optimize image
– Bowel interference is common
To Evaluate the ThoraxTo Evaluate the Thorax
Move probe – cephalad– longitudinal
ImageLiver
Diaphragm
Pleural space
Ma O John, Mateer J, Trauma Ultrasound Examination Versus Chest Radiography in the Detection of Hemothorax
Ann Emerg Med: March 1997
240 trauma US study patients 26 had hemothorax ( CT or chest tube) CXR and US
– 0 false positive– 1 false negative – 25 true positive – 214 true negative
Pelvic ViewPelvic View
Probe should be placed in the suprapubic position
Either can be transverse or longitudinal
Helpful to image before placement of a Foley catheter
Pelvic View – Sagittal Pelvic View – Sagittal
Fluid in front of the bladder
If bladder is empty or Foley already placed:
Trick of trade– IV bag on abdomen– Scan through bag
clot bladder
FAST AlgorithmFAST Algorithm
NormalHemodynamicStatus
Altered MSConfounding InjuryGross Hematuria
HCT < 35%
Repeat U/S 30’HCT at 4hObserve 8h
US:Free fluid?
Nonoperative or
cirrhosis?LAPAROTOMY
DPL
Abdominal CT
PeritonealIrritation?
DPL
NO
NO NO
USFree fluid?
NO
Branney, et. al.J Trauma, 1997
YES
YES
YES
YES
YES
NO NO
YES
Penetrating Thoracic Penetrating Thoracic InjuryInjury
Clinical challenge– Where is the penetration?– What was the weapon?– What was the trajectory?– What organ(s) have been injured?– Improved outcomes in patients with normal or
near-normal vital signs
Penetrating Cardiac Penetrating Cardiac TraumaTrauma
Pericardial effusion– May develop suddenly or surreptitiously– May exist before clinical signs develop
Salvage rates better if detected before hypotension develops
Clinical CaseClinical Case
QD is 37 year old male brought in by EMS for ingesting entire bottle of unidentified red and white pills. In the ambulance bay he pulls out a knife and stabs himself in the left nipple.
Clinical CaseClinical Case
Initial BP 116/72, pulse 109 RR 24. IV’s placed.
No JVD, Clear breath sounds, non tender abdomen
As CXR is about to be done, pulse increases to 134.
Bedside ultrasound is done while cartridge is developed.
Subcostal ViewSubcostal ViewMost practical in trauma setting
Away from airway and neck/chest procedures
Also called Sub-Xyphoid view
Occult Penetrating Cardiac Occult Penetrating Cardiac TraumaTrauma
Observation unreliableSubxiphoid window
– Invasive– 100% sensitive, 92% specific– Negative exploration rates (as high as 80%)
Ultrasound reliable indicator of even small pericardial effusion
Trauma StudyTrauma Study
The role of ultrasound in patients with possible penetrating cardiac wounds: a prospective multicenter study.
Rozycki GS: J Trauma. 1999
Pericardial scans performed in 261 patients Sensitivity 100%, specificity 96.9% PPV: 81% NPV:100% Time interval BUS to OR: 12.1 +/- 5.9 min
Avoid PitfallsAvoid Pitfalls
Normal echo does not definitively rule out major pericardial injury
Repeat echo with clinical pictureEpicardial fat pad may easily be
misinterpreted as “clot”Hemothorax may be confused with
pericardial effusion
Blunt Cardiac TraumaBlunt Cardiac Trauma
Basic Assessments– Pericardial effusion– Assess for wall motion
abnormality – RV:
closest to anterior chest wall
Most likely to be injured
Advanced Assessments– Assess thoracic aorta –
may need TEE to see all of thoracic aorta
Hematoma Intimal flap Abnormal contour
– Valvular dysfunction or septal rupture
Blunt cardiac traumaBlunt cardiac trauma
Injuries difficult to assess by FAST– Valvular incompetence– Myocardial rupture– Intracardiac thrombosis– Ventricular aneurysm– Coronary Thrombosis– Intra-cardiac Thrombosis