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

FAST

Focused Abdominal Sonography in Trauma

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

FASTFAST

Perform during – Resuscitation– Physical exam – Stabilization

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

Scan PlaneScan Plane

Same image if probe positioned– Anterior– Mid axillary– Posterior

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

Normal Morison’s Pouch

Free fluid in Morison’s

Pouch

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

LUQLUQ

Probe at left posterior axillary line

Near ribs 9 and 10

Angle probe obliquely (avoid ribs)

LUQ Scan PlaneLUQ Scan Plane

More difficult– Acoustic window

(spleen) is smaller than liver

– Mild inspiration will optimize image

– Bowel interference is common

LUQ ScanLUQ Scan

spleen

kidney

*Splenorenal fossa – a potential space

**

**

Normal Spleno-renal

view

Free fluid around spleen

To Evaluate the ThoraxTo Evaluate the Thorax

Move probe – cephalad– longitudinal

ImageLiver

Diaphragm

Pleural space

HemothoraxHemothorax

liver

diaphragmfluid

Small Pleural EffusionSmall Pleural Effusion

Large Pleural EffusionLarge Pleural Effusion

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

Pelvis (Long View)Pelvis (Long View)

Pelvis: TransversePelvis: Transverse

Normal Transverse

pelvic

Fluid in pelvis

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

Blood in the PelvisBlood in the Pelvis

Free fluid in the pelvisFree fluid in the pelvis

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

Ultrasound in the Detection of InjuryFrom Blunt or Penetrating Thoracic Trauma

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.

Clinical CaseClinical Case

Clinical CaseClinical Case

Patient is taken to the OR

Penetrating cardiac wound is repaired

Subcostal ViewSubcostal ViewMost practical in trauma setting

Away from airway and neck/chest procedures

Also called Sub-Xyphoid view

Subcostal ViewSubcostal View

Subcostal View Subcostal View

Pericardial FluidPericardial Fluid

fluid

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

“ The most important preoperative objective in the management of the patient with trauma is to ascertain whether or not laparotomy is needed, and not the diagnosis of a specific organ injury”