Emergency Ultrasound in Trauma - LVHN

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Transcript of Emergency Ultrasound in Trauma - LVHN

  • Emergency Ultrasound in Trauma

    Anthony J Weekes MD, RDMS

    Janet G. Alteveer, MD

    Sarah Stahmer, MD

  • Clinical Case

    GR 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 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 Case

    2 large IVs placed, CXR done. Blood tests sent. Bedside ultrasound done.CXR revealed lower rib fractures, no HTX or PTX

  • Clinical 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 Abdominal Trauma

    Diagnostic Peritoneal Lavage (DPL)CAT ScanUltrasound (FAST exam)

  • Diagnostic 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 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

  • FAST

    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 Principles

    Detects free intraperitoneal fluidBlood/fluid pools in dependent areasPelvis

    Most dependent

    Hepatorenal fossa

    Most dependent area in supramesocolic region

  • FAST Principles

    Pelvis and Supra-mesocolic areas communicate

    Phrenicolic ligament prevents flow

    Liver/spleen injury

    Represents 2/3 of cases of blunt abdominal trauma

  • FAST- principles

    Intraperitoneal fluid may be

    Blood

    Preexisting ascites

    Urine

    Intestinal contents

  • FAST limitations

    US relatively insensitive for detecting traumatic abdominal organ injuryFluid 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 picture

    Operator dependent

  • Evidence supporting use of FAST

    Multiple studies in USA by EM and trauma surgeonsStudies 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 Morisons 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 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

  • Results

    53/358 (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 Study

    Rozycki G, et al 1998 Surgeon-performed ultrasound for the assessment of truncal injuries. Lessons learned from 1540 patientsFAST exam on patients with precordial or transthoracic wounds or blunt abdominal trauma

  • Protocol:

    + Pericardial fluid OR

    StableCT

    +IP fluid

    UnstableOR

    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 Societies

    Established clinical role in Europe, Australia, Japan, IsraelGerman Surgical Society requires candidates proficiency in ultrasoundUnited States

    US in ATLS

    US policies by frontline specialties

    American College of Surgeons

    ACEP,SAEM & AAEM

  • FAST

    Perform during

    Resuscitation

    Physical exam

    Stabilization

  • Equipment

    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 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 for Trauma (FAST)

    Consists of 4 views

    Subxiphoid

    Right Upper Quadrant

    Left Upper Quadrant

    Pouch of Douglas

  • FAST

    Increased sensitivity with increased number of viewsWill identify pleural effusionsReliably detects as little as 50-100cc in the thoraxSensitivity >96%, specificity 99-100%

  • Clinical experience with FAST

    Intraperitoneal fluid

    Sensitivity 82-98%, specificity 88-100%

    Morisons pouch alone 36-82% sensitivityIncreased sensitivity with

    Increasing number of views

    Trendelenberg

    Serial examinations

    Can detect as little as 250cc of free fluid

  • Clinical 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

  • RUQ

    Probe at right thoraco-abdominal junctionLiver : large acoustic windowProbe marker cephaladRib interference?

    Rotate 30 counterclockwise

  • Scan Plane

    Same image if probe positioned

    Anterior

    Mid axillary

    Posterior

  • RUQ

    Image on screen:

    Liver cephalad

    Kidney inferiorly

    Morisons Pouch*: space between Glissons capsule and Gerotas fascia

    *

    *

    *

    *

  • Normal RUQ

    Image kidney

    Longitudinally

    Transversely

    Two toned structure

    Cortex/medulla

    Renal sinus

  • Appearance of blood

    Fresh blood

    Anechoic (black)

    Coagulating blood

    First hypoechoic

    Later hyperechoic

  • Normal Morisons Pouch

    Free fluid in Morisons 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 Morisons 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 Morisons 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 Ultrasound

    Affected by positioningLocation of bleedRate of bleedingOperator Experience

    Value of sensitivity of Ultrasound:

    Detects clinically injuries

    Non-detection of fluid

    May indicate self- limited bleeding

  • All Fluid is not Blood

    AscitesRuptured Ovarian CystLavage fluidUrine from ruptured bladder

  • Mimics 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

  • Pitfalls

    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 accumulatedNot repeating the scan

  • LUQ

    Probe at left posterior axillary line

    Near ribs 9 and 10

    Angle probe obliquely (avoid ribs)

  • LUQ Scan Plane

    More difficult

    Acoustic window (spleen) is smaller than liver

    Mild inspiration will optimize image

    Bowel interference is common

  • LUQ Scan

    spleen

    kidney

    *Splenorenal fossa a potential space

    *

    *

    *

    *

  • Normal Spleno-renal view

    Free fluid around spleen

  • To Evaluate the Thorax

    Move probe

    cephalad

    longitudinal

    Image

    Liver

    Diaphragm

    Pleural space

  • Hemothorax

    liver

    diaphragm

    fluid

  • Small Pleural Effusion

    Large 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 patients26 had hemothorax ( CT or chest tube)CXR and US

    0 false positive

    1 false negative

    25 true positive

    214 true negative

  • Pelvic View

    Probe should be placed in the suprapubic positionEither can be transverse or longitudinalHelpful to image before placement of a Foley catheter

  • Pelvis (Long View)

  • Pelvis: Transverse

  • Normal Transverse pelvic

    Fluid in pelvis

  • Pelvic View Sagittal

    Fluid in front of the bladderIf bladder is empty or Foley already placed:

    Trick of trade

    IV bag on abdomen

    Scan through bag

    clot

    bladder

  • Blood in the Pelvis

  • Free fluid in the pelvis

  • FAST Algorithm

  • Ultrasound in the Detection of Injury

    From Blunt or Penetrating Thoracic

    Trauma

  • Penetrating Thoracic Injury

    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 Trauma

    Pericardial effusion

    May develop suddenly or surreptitiously

    May exist before clinical signs develop

    Salvage rates better if detected before hypotension develops

  • Clinical 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 Case

    Initial BP 116/72, pulse 109 RR 24. IVs placed. No JVD, Clear breath sounds, non tender abdomenAs CXR is about to be done, pulse increases to 134. Bedside ultrasound is done while cartridge is developed.

  • Clinical Case

  • Clinical Case

    Patient is taken to the OR

    Penetrating cardiac wound is repaired

  • Subcostal View

    Most practical in trauma settingAway from airway and neck/chest proceduresAlso called Sub-Xyphoid view

  • Subcostal View

  • Subcostal View

  • Pericardial Fluid

    fluid

  • Occult Penetrating Cardiac Trauma

    Observation unreliableSubxiphoid window

    Invasive

    100% sensitive, 92% specific

    Negative exploration rates (as high as 80%)

    Ultrasound reliable indicator of even small pericardial effusion

  • Trauma 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 patientsSensitivity 100%, specificity 96.9%PPV: 81% NPV:100%Time interval BUS to OR: 12.1 +/- 5.9 min

  • Avoid Pitfalls

    Normal echo does not definitively rule out major pericardial injuryRepeat echo with clinical pictureEpicardial fat pad may easily be misinterpreted as clotHemothorax may be confused with pericardial effusion

  • Blunt 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 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

    Normal

    Hemodynamic

    Status

    Altered MS

    Confounding Injury

    Gross Hematuria

    HCT < 35%

    Repeat U/S 30

    HCT at 4h

    Observe 8h

    US:

    Free fluid?

    Nonoperative

    or

    cirrhosis?

    LAPAROTOMY

    DPL

    Abdominal CT

    Peritoneal

    Irritation?

    DPL

    NO

    NO

    NO

    US

    Free

    fluid

    ?

    NO

    Branney, et. al.

    J Trauma, 1997

    YES

    YES

    YES

    YES

    YES

    NO

    NO

    YES