Download Free Medical Focused Emergency Ultrasound: Evaluation of the Abdominal Aorta PowerPoint Presentation

Focused Emergency Ultrasound: Evaluation of the Abdominal Aorta PowerPoint Presentation

DOWNLOAD MEDICAL POWERPOINT PRESENTATION

About This Presentation

Description : Check out this medical presentation on Aorta, which is titled "Focused Emergency Ultrasound: Evaluation of the Abdominal Aorta", to know about the clinical role of bedside ultrasound in screening for AAA, the technique of acquiring sonographic images of the aorta, the sonographic appearance of the normal aorta, and the sonographic appearance of AAA.

Tags : Aorta, Focused Emergency Ultrasound, Evaluation, Abdominal Aorta, clinical role, bedside ultrasound, screening for AAA

Published on : May 25, 2021 | Views : 1581 | Downloads : 5

Shareable Url :

Embed Code :

Comment

Transcript

Slide 1-

FOCUSED EMERGENCY ULTRASOUND: EVALUATION OF THE ABDOMINAL AORTA MARY BETH PHELAN, MD, RDMS DEPARTMENT OF EMERGENCY MEDICINE FOREDTERT MEMORIAL HOSPITAL
Slide 2-

SAEM 2 Lecture Objectives Describe clinical role of bedside ultrasound in screening for AAA Describe the technique of acquiring sonographic images of the aorta Describe the sonographic appearance of the normal aorta Describe the sonographic appearance of AAA
Slide 3-

Case History
Slide 4-

SAEM 4 Case History A 62-year-old man comes to the emergency department at 11PM complaining of left flank pain for approximately 2 hours. He has a history of hypertension. His initial vital signs are: HR 98, RR 24, BP 190/105, Temp 98.0.
Slide 5-

SAEM 5 Case History The emergency medicine resident equipped with the latest in emergency medicine ultrasound technology and training, IMMEDIATELY performs an abdominal ultrasound on the patient. This exam reveals the following:
Slide 6-

SAEM 6
Slide 7-

SAEM 7 Case History The patient is taken to the OR after only 30 minutes in the ED.
Slide 8-

OVERVIEW Epidemiology Clinical presentation Anatomy US exam Sonographic anatomy Scanning techniques Pitfalls
Slide 9-

Epidemiology AAA present in 2-4% of the population > 50 Incidence increasing Male > female 10,000 deaths/yr Rupture has a > 80% mortality rate
Slide 10-

Epidemiology: Risk Factors Cardiovascular disease Family History increases risk 10-20% Age > 50 Smoker
Slide 11-

SAEM 11 Clinical Perspective Settings in which to perform US in the ED Abdominal/back/flank pain and hypotension Stable elderly patient with abdominal or back pain
Slide 12-

Clinical Perspective Rate of expansion variable 4-4.9 cm AAA has a 3.3% risk of rupture 5cm AAA has a 14% risk of rupture > 5cm has a 20-40% risk of rupture
Slide 13-

Clinical Perspective 4cm or less: annual US examinations Between 4-5 cm: US every 6 months Greater than 5cm: Elective repair Mortality rate for elective repair is 5%
Slide 14-

Clinical Presentation Highly variable Classic triad: Abdominal/Back pain Pulsatile mass Hypotension Less than 1/3 of patients will have the triad
Slide 15-

SAEM 15 Clinical Presentation Diagnosis A formidable clinical challenge Notorious for masquerading as renal colic May be mistaken for: Diverticullitis GI bleed MI Musculoskeletal back pain
Slide 16-

Clinical Presentation Stable vital signs Back or flank pain, left side > right Testicular or leg pain Hypertension Mortality rate same as elective repair
Slide 17-

Clinical Presentation Vast majority are retroperitoneal 10 -30 % intraperitoneal GI bleeding most often seen in patients with aortic grafts Mortality 50%
Slide 18-

Does this patient have an abdominal aortic aneurysm?LEDERLE, JAMA 99 2 groups Sensitivity of examination for ruptured AAA Sensitivity of exam with increasing size of AAA CONCLUSION:Cannot be relied on to exclude AAA
Slide 19-

Misdiagnosis of Ruptured Abdominal Aortic Aneurysms MARSTON W ET AL J OF VASCULAR SURG 1992 Misdiagnosis= delay >6hr or other diagnosis Most common physical findings in misdiagnosed group: ABD PAIN, SHOCK, BACK PAIN Pulsatile mass present more often in correctly diagnosed group
Slide 20-

SUSPECTED LEAKING ABDOMINAL AORTIC ANEURYSM:USE OF SONOGRAPHY IN THE EMERGENCY ROOM SHUMAN WP, ET AL, RADIOLOGY 88 US IN ED FOR SUSPECTED AAA 1 MIN EXAM CORRECTLY IDENTIFIED 31/32 AAA DECISION TO OPERATE BASED ON 3 CRITERIA CORRECT 21/22 DX EXTRALUMINAL BLOOD BY SONOGRAPHY POOR 4% (1/24) NO FALSE NEG EXAMS
Slide 21-

Diagnosing AAA Palpation of the abdomen alone Plain radiographs Computed tomography ULTRASOUND
Slide 22-

Diagnosis: PE Absence of mass does not R/O AAA Obesity Bleeding into retroperitoneum may create doughy abdomen. Hypotension minimizes pulsations
Slide 23-

Diagnosis: Plain Radiographs AAA can be seen in 60-75% of cases Calcification of aortic wall Paravertebral mass Cross table lateral most helpful view Negative study not helpful
Slide 24-

Diagnosis: CT Scan Near 100% accuracy Better demonstration of extent of aneurysm Will detect complications of the aneurysm Retroperitoneal blood Dissection Drawbacks Contrast Patient has to leave the ED Delays time to diagnosis
Slide 25-

SAEM 25 Diagnosis: US Ultrasound Best test for detection of AAA in the ED Sensitivity 97% to 100% Small percentage can not be imaged due to bowel gas 6% in one study
Slide 26-

SAEM 26 Diagnosis: US Ultrasound In some studies as accurate as CT Measurements within 3 mm of surgical specimens Angiography may underestimate AAA diameter
Slide 27-

SAEM 27 Diagnosis: US Emergency department ultrasound scanning for abdominal aortic aneurysm: accessible, accurate and advantageous Kuhn et al. Ann Emerg Med 2000 “Relative neophytes can perform aortic ultrasound scans accurately. These scans appear useful as a screening measure in high-risk emergency patients; they may also aide in rapidly verifying the diagnosis in patients who require immediate surgical intervention”
Slide 28-

SAEM 28 Diagnosis: US ED Ultrasound Improves Time to Diagnosis and Survival in Ruptured AAA Plummer D, et al: Abstract at 1998 SAEM, Chicago, IL. Average time to diagnosis by bedside US = 5.4 minutes Average time to diagnosis by CT = 83 minutes Average time to OR for diagnosis by US = 12 minutes Average time to OR for diagnosis by CT = 90 minutes
Slide 29-

US EXAM Transducer is 2.5-3.0MHz curvilinear Place the transducer in the subxiphoid area, using the left lobe of the liver as an acoustic window Pressure must be applied to displace bowel gas The aorta must be examined in both the longitudinal and transverse planes
Slide 30-

Longitudinal Orientation
Slide 31-

SAEM 31 Transverse Orientation Orientation is similar to that of a CT scan Position probe is perpendicular to long axis of body or to long axis of object that is being studied IVC,Liver Aorta
Slide 32-

US EXAM The aorta appears as an anechoic, pulsatile tubular structure to the left of the spine After the longitudinal scan, the transducer is rotated 90 degrees to the aorta to obtain transverse views. The key landmark in the transverse view is to locate the spinal column as a hypoechoic area at the bottom of the screen. The aorta is located above and to the left of the spine
Slide 33-

AORTA IVC Left sided structure Thick vascular wall Not compressible Pulsatile Right sided structure Thin wall Will collapse “Sniff” Valsalva May pulsate from aortic transmission
Slide 34-

US EXAM Measure from outside wall to outside wall An aneurysm is identified as any measurement of 3 cm or greater Measure at: Epigastric region Take off of SMA 3-4 cm intervals to bifurcation Measure any aneurysm
Slide 35-

US EXAM Obesity or excessive bowel gas may obscure the aorta A coronal view of the aorta may be a reasonable alternative The patient is supine The transducer is placed in the mid-axillary line (probe indicator toward the patient’s head) The aorta is visualized adjacent to the vena cava
Slide 36-

SONOGRAPHIC APPEARANCE OF THE NORMAL AORTA: LONGITUDINAL
Slide 37-

SONOGRAPHIC APEARANCE OF THE NORMAL AORTA: TRANSVERSE Bifurcation Mid portion
Slide 38-

SONOGRAPHIC APPEARANCE OF THE NORMAL AORTA (L LATERAL DECUB/CORONAL)
Slide 39-

ABDOMINAL AORTIC ANEURYSM 90% of AAA are infra-renal 70% involve the renal vessels Thrombus is common, and usually forms on the antero-lateral walls of the aneurysm Two forms Sacular Fusiform – most common
Slide 40-

ABDOMINAL AORTIC ANEURYSM First sign may be loss of normal taper AP diameter > 3CM Focal dilitation even if less than 3 cm Thrombus Intimal flap
Slide 41-

AORTIC ANEURYSM
Slide 42-

SAEM 42 Large fusiform AAA
Slide 43-

SAEM 43 AAA with clot
Slide 44-

SAEM 44 Another AAA with clot
Slide 45-

ULTRASOUND EXAM: PITFALLS Bowel gas can be a major problem Apply pressure Roll the patient on their left side ( use the liver as an acoustic window) Does not detect complications of AAA Retroperitoneal rupture Dissection CT/MRI/angiography for stable patients is still recommended
Slide 46-

Pitfalls in Technique Failure to acquire high resolution images due to bowel gas Inaccurate measurements – do not measure what you cannot see! Distinguishing the IVC from the aorta Not identifying extraluminal fluid Failing to distinguish the normal “tortuous” aorta from an abdominal aortic aneurysm.