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 IV’s 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 Scan Ultrasound (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 Disadvantages 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

Focused Abdominal Sonography in Trauma FAST

FAST Advantages Disadvantages 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 fluid Blood/fluid pools in dependent areas Pelvis 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 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 picture Operator dependent

Evidence supporting use of FAST Multiple studies in USA by EM and trauma surgeons Studies from Europe and Japan Policy statements by specialty organizations

Jehle, D., et al, Am J Emerg Med, 1993 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 study A prospective study of surgeon-performed ultrasound as the primary adjuvant modality of injured patient assessment. 1994 Rozycki et al. N=358 patients Outcomes 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 patients FAST exam on patients with precordial or transthoracic wounds or blunt abdominal trauma

Precordial/Transthor : Sens 100%, Spec 99.3% 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 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

FAST Perform during Resuscitation Physical exam Stabilization

Equipment Curved array Various “footprints” Variable frequencies 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 seconds Number of views dependent on clinical question and findings on initial views Total exam time usually < 3-5 minutes 1988 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 views Will identify pleural effusions Reliably detects as little as 50-100cc in the thorax Sensitivity >96%, specificity 99-100%

Clinical experience with FAST Intraperitoneal fluid Sensitivity 82-98%, specificity 88-100% Morison’s pouch alone 36-82% sensitivity Increased sensitivity with Increasing number of views Trendelenberg Serial examinations Can detect as little as 250cc of free fluid

Clinical Experience Solid organ disruption Hollow viscus injury 40% sensitivity for all organs 33-94% for splenic injury Hollow viscus injury Sensitivity 57% Retroperitoneal injury Sensitivity for identification of hemorrhage <60%

RUQ Probe at right thoraco-abdominal junction Liver : large acoustic window Probe marker cephalad Rib interference? Rotate 30° counterclockwise

Scan Plane Same image if probe positioned Anterior Mid axillary Posterior

RUQ Image on screen: Liver cephalad Kidney inferiorly Morison’s Pouch*: space between Glisson’s capsule and Gerota’s fascia * * * *

Normal RUQ Image kidney Two toned structure Longitudinally Transversely Two toned structure Cortex/medulla Renal sinus

Appearance of blood Fresh blood Coagulating blood Anechoic (black) First hypoechoic Later hyperechoic

Normal Morison’s Pouch Free fluid in Morison’s Pouch

Peritoneal lavage fluid infused in 100 patients Branney, S.W. et al: Quantitative sensitivity of ultrasound in detecting free intraperitoneal fluid J Trauma:1995: 39 Peritoneal lavage fluid infused in 100 patients Simultaneous 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

Volume Assessment by US 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

Detection of Fluid by Ultrasound 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 Blood Ascites Ruptured Ovarian Cyst Lavage fluid Urine from ruptured bladder

Mimics of Fluid in RUQ Perinephric fat Abdominal inflammation 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 Scanning too soon before enough blood has accumulated 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 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 Image cephalad longitudinal Liver Diaphragm Pleural space

Hemothorax liver diaphragm fluid

Small Pleural Effusion Large Pleural Effusion

240 trauma US study patients 26 had hemothorax ( CT or chest tube) 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 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: Transverse

Normal Transverse pelvic Fluid in pelvis

Pelvic View – Sagittal Fluid in front of the bladder clot bladder Fluid in front of the bladder If bladder is empty or Foley already placed: Trick of trade IV bag on abdomen Scan through bag

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. 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 Case

Clinical Case Patient is taken to the OR Penetrating cardiac wound is repaired

Subcostal View Most practical in trauma setting Away from airway and neck/chest procedures Also called Sub-Xyphoid view

Subcostal View

Subcostal View

Pericardial Fluid fluid

Occult Penetrating Cardiac Trauma Observation unreliable Subxiphoid 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 patients Sensitivity 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 injury Repeat echo with  clinical picture Epicardial fat pad may easily be misinterpreted as “clot” Hemothorax may be confused with pericardial effusion

Blunt Cardiac Trauma Basic Assessments Advanced 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”