Transcript ED Ultrasound

ED Ultrasound
Rob Hall MD
Oral Presentation
PGY4 Emergency Medicine
October 30th, 2003
ED echo (“Eddie”)
ED ultrasound
WHY SHOULD
WE?

Ultrasound imaging enhances the physician's ability to
evaluate, diagnose, and treat emergency department
(ED) patients. Because ultrasound imaging is often timedependent in the acutely ill or injured patient, the
emergency physician is in an ideal position to use this
technology. Focused ultrasound examinations provide
immediate information and can answer specific
questions about the patient's physical condition. Such
bedside ultrasound imaging is within the scope of
practice of emergency physicians.
CAEP Position Statement:Feb 1999

Ultrasound should be available 24 hours per day
for emergency patients, particularly for those
being evaluated for cardac tamponade,
abdominal aortic aneurysm, abdominal trauma,
and ectopic pregnancy. A focused or limited
bedside Emergency Department ultrasound
should be available, performed by technicians,
radiologists, or appropriately trained, qualified
and experienced Emergency Physicians.
Who is doing ED ultrasound in the USA?
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Counselman. Acad Emerg Med 2000
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Mail out survery
80% response rate
95% of emergency medicine training programs
teaching and using ultrasound
Accounting for response bias --------- 75% of
programs
Conclusion: ED ultrasound is mainstay in US
emerg programs
What do all these places have in
common?
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Winnipeg
Lethbridge
Kelowna
Lillooet
Abbotsford
Vancouver
Victoria
Nanaimo
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Fredericton
Sacre’ Coeur
Granby
St-Paul
Monmagny
Montreal
Ottawa
Torondo
Windsor
Brampton
Sarnia
Kingston
Parry Sound
Huntsvile
Sault Sainte
Marie
What do all of these specialists
have in common?
Main objective: literature review of ED
ultrasound
AAA
Pregnancy
4 Primary Indications
Cardiac
FAST
Main objective: literature review of ED
ultrasound
AAA
Pregnancy
4 Primary Indications
Cardiac
FAST
AAA: objectives
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Is there literature
supporting ED
ultrasound to detect
AAAs?
How much training
is required be
accurate?
AAA: general information
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Ultrasound done by radiology is nearly 100%
sensitive for the detection of AAA
Ultrasound measurements correlate with CT and
laparotomy measurements w/I 2-3mm
Physical examination is unreliable: Lederle
JAMA 1999
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3.0-3.9cm
4.0-4.9cm
> 5.0cm
29% sensitivity
50% sensitivity
75% sensitivity
AAA: 6 prospective studies
Study
Size
Training Sens. %
(C.I.s)
Spec.%
(C.I.s)
Accurracy
(C.I.s)
Jones
2003
N=66
8hrs
98
(86-100)
100
(87-100)
99
(90-100)
Rowland
2001
N=33
3 days
100
(74-100)
100
(85-100)
100
(90-100)
Kuhn
2000
N=68
3 days
100
(87-100)
100
(91-100)
100
Mandavia
2000
N=44
16hrs
50
(15-70)
95
(79-98)
93
Lanoix
2000
N=20
4hrs
100
(40-100)
100
(76-100)
100
Schlager 95
N=11
16hrs
100
100
100
AAA: 6 prospective studies
Study
Size
Training Sens. %
(C.I.s)
Spec.%
(C.I.s)
Accurracy
(C.I.s)
Jones
2003
N=66
8hrs
98
(86-100)
100
(87-100)
99
(90-100)
Rowland
2001
N=33
3 days
100
(74-100)
100
(85-100)
100
(90-100)
Kuhn
2000
N=68
3 days
100
(87-100)
100
(91-100)
100
Mandavia
2000
N=44
16hrs
50
(15-70)
95
(79-98)
93
Lanoix
2000
N=20
4hrs
100
(40-100)
100
(76-100)
100
Schlager 95
N=11
16hrs
100
100
100
AAA
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Jones. Emergency Medicine 2003.
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Prospective
N=66 scans for AAA
Initial training was an 8 hour course covering four
primary indications
Gold standard = CT or laparotomy
Results
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Sensitivity 98% (86-100)
Specificity 100% (87-100)
Accuracy 99% (90-100)
AAA
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Khun. Ann Emerg Med 2000
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Prospective, N=68
Training was 3 days (2hrs for AAA)
Gold standard = radiologist review of video
Results
Sensitivity 100% (87-100)
 Specificity 100% (91-100)
 Accuracy 100% (no CI)
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AAA: conclusions
 Emergency
Physicians can
achieve accuracy in detection of
AAAs with limited training
 Our scans should aim to be 95%
accurate
Main objective: literature review of ED
ultrasound
AAA
Pregnancy
4 Primary Indications
Cardiac
FAST
Cardiac: objectives
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Can ED ultrasound be
used to predict survival
post cardiac arrest?
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Is there literature
supporting ED ultrasound
for the detection of
pericardial effusions? LV
function?
Cardiac arrest and ED ultrasound
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Blaivas Acad Emerg
Med 2001
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Prospective, N=166
Cardiac standstill
0/136 survival
Cardiac activity 20/33
survival
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Salen Acad Emerg
Med 2001
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Prospective, N=102
Standstill: 2/61
survival
Cardiac activity: 11/41
survival
ETC02 production was
a better predictor
Cardiac: conclusions
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There is insufficient evidence to prove that
cardiac standstill is a reliable indicator of
cardiac arrest survival
Cardiac standstill should be considered in
the decision to terminate resuscitation but
should not be the sole criterion
Cardiac: LV function
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Moore. Acad Emerg
Med 2002
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Looked at atraumatic
hypotensive patients
Prospective, N=51,
cardiology as gold
standard
Ratings: normal (1), mod
depressed (2), severely
depressed (3)
Kappa 0.61 (0.39-0.83)
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EP ratings
1
2
3
1
17
5
0
2
7
9
2
3
0
2
8
Cardiologist ratings
Cardiac: pericardial effusions
Study
Method Training
Sens
Spec
Accurac
y
Mandavia
2001
N=515
16hrs
96
(90-99)
98
(96-99)
97.5
(95-99)
Mandavia
2000
N = 28
16hrs
100
100
100
(50-100) (60-100)
Lanoix
2000
N=67
4hrs
88
(47-99)
Ma 1995
N=245
10hrs +
100
20 exams
98
(90-99)
97
99
99
Cardiac: pericardial effusions
Study
Method Training
Sens
Spec
Accurac
y
Mandavia
2001
N=515
16hrs
96
(90-99)
98
(96-99)
97.5
(95-99)
Mandavia
2000
N = 28
16hrs
100
100
100
(50-100) (60-100)
Lanoix
2000
N=67
4hrs
88
(47-99)
Ma 1995
N=245
10hrs +
100
20 exams
98
(90-99)
97
99
99
Cardiac: pericardial effusions
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Mandavia. Ann Emerg Med 2001
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Prospective study, N=515
Training = 16hrs, 5hrs dedicated to echo
Gold standard = blinded cardiologist interpretation
All scans were clinically indicated
Results:
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Technically adequate in 93%
Sensitivity 96% (90-99)
Specificity 98% (96-99)
Accuracy 97.5% (95-99)
Cardiac: conclusions
Emergency Physicians can achieve
accuracy in detection of pericardial
effusion with limited training
 Our scans should aim to be 95%
accurate
 Determination of LV function requires
further study
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Main objective: literature review of ED
ultrasound
AAA
Pregnancy
4 Primary Indications
Cardiac
FAST
Pregnancy: objectives
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How does ED ultrasound
affect patient
satisfaction? How does
ED ultrasound affect ED
flow?
Is there literature
supporting the accuracy
of ED ultrasound in
pregnancy?
Pregnancy: patient satisfaction
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Krubel. Am J Emerg Med . 1998
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Prospective; ½ got ED ultrasound
Survey of 96 ED visits
Showed
Improved overall satisfaction with ED care
 Improved satisfaction with tests performed
 Reduced desire for a second opinion
 Reduced anxiety after the ED visit
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Pregnancy: ED flow
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Remember the chart
review we did last
year: pregnancy
related u/s
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Useful
Not Useful
Document IUP was
found in 72% of initial
ultrasounds
ED ultrasound would
likely be useful in
72% of patients
Pregnancy: ED flow
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Rogerson. Acad Emerg Med
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ED RUQ ultrasound is associated with a
reduced time to diagnosis and treatment of
rupture ectopic pregnancies
Retrospective review
Time
ED u/s
Radiology u/s
To Dx
 To OR
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58 min (28-87)
111 min (69-153)
197 (162-232)
322 (270-364)
Pregnancy: ED flow
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Blaivas. Acad Emerg Med 2000
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Do emergency physicians save time when
locating a live IUP with bedside ultrasound?
Retrospective review of 1419 charts
Length of stays
ED ultrasound
 Rad ultrasound
 Absolute diff
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3hr 40min
4hr 39min
59 min, p=0.0001
Pregnancy: ED flow
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Burgher. Acad Emerg Med 1998
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Before and after ED u/s introduction study
Mean L.O.S. before: 234 min
Mean L.O.S. after: 164 min
Difference 70 min, p=0.0003
Shih. Ann Emerg Med
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Prospective; L.O.S. decreased when ultrasound
showed an IUP
ED ultrasound: mean L.O.S. 45 min
Radiology ultrasound: mean L.O.S. 177min
Pregnancy: conclusions
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ED ultrasound can improve ED flow
ED ultrasound can improve patient
satisfaction
Pregnancy: detecting an IUP
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How accurate can ER docs be after
minimal training?
Is it safe?
Pregnancy: detecting and IUP
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Studies look at
sensitivity and
specificity of
detecting an IUP
not an ectopic
Specificity is
therefore more
important!
IUP
present
IUP absent
U/S shows
IUP
True
Positive
False
Positive
(BAD!!!!!!)
U/S doesn’t
show IUP
False
Negative
True
Negative
Pregnancy: 6 prospective studies
Study
Size
Training
Sens. %
(C.I.s)
Spec.%
(C.I.s)
Accurracy
(C.I.s)
Mandavia
2000
N=101
16 hrs
76
(61-99)
92
(76-96)
83%
Lanoix
2000
N=33
4hrs
100
(82-100)
90
(54-99.5)
97%
Shih
1997
N=125
24hrs
+10exams
94%
(82-98%)
100
(83-100)
96%
Durham
1997
N=136
24hrs + 10
exams
Mateer
1995
N=152
12hrs + 12
exams
Jehle 1989
N=40
??
97%
(91-97)
99
(97-100)
93
(80-100)
97.5
Pregnancy: 6 prospective studies
Study
Size
Training
Sens. %
(C.I.s)
Spec.%
(C.I.s)
Accurracy
(C.I.s)
Mandavia
2000
N=101
16 hrs
76
(61-99)
92
(76-96)
83%
Lanoix
2000
N=33
4hrs
100
(82-100)
90
(54-99.5)
97%
Shih
1997
N=125
24hrs
+10exams
94%
(82-98%)
100
(83-100)
96%
Durham
1997
N=136
24hrs + 10
exams
Mateer
1995
N=152
12hrs + 12
exams
Jehle 1989
N=40
??
97%
(91-97)
99
(97-100)
93
(80-100)
97.5
Pregnancy: detecting an IUP
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Shih. Ann Emerg Med 1997
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Prospective, N=125
Training: 24hrs + 10 proctored exams
Gold standard was formal ultrasound
Some were transvag some transabd
Results
Sensitivity for IUP: 94% (C.I. 82-98%)
 Specificity for IUP: 100% (C.I. 83-100)
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Pregnancy: detecting an IUP
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Durham. Ann Emerg Med 1997
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Prospective, N=136
Training: 24hrs + 20 proctored exams (variable)
Gold standard: formal ultrasound
Pre-defined possible ultrasound results and
correlated ER interpretation vs formal ultrasound
result
Results showed overall 97% accurracy (91-97% C.I.)
Pregnancy: detecting an IUP:
Durham. Ann Emerg Med 1997
Diagnosis
Correct Incorrect Accuracy (95%C.I.)
IUP with fetal 87
pole
0
100% (97-100)
IUP <6wks
3
75% (59-93)
Indeterminate 15
0
100% (82-100)
Ectopic
7
1
88% (60-95)
Bl. Ovum
2
0
Molar
1
0
Totals
121
4
9
97% (91-97)
Pregnancy: detecting an IUP
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Mateer. Acad Emerg Med
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Prospective, N=152
Training: 12hrs + 12 proctored exams
Gold standard: interpretation by gyne
Also looked at results compared to final outcome
ER interpretation versus gyne interpretation
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Correct 94%
Incorrect 4.7%
Inadequate 1.4%
Pregnancy: conclusions
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Emergency physicians can accurately
detect Intra-uterine pregnancy
Our scans should aim to be 95% accurate
Specificity for IUP needs to be 100%
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If you’re not sure it’s an IUP, call it a “NO
definitive IUP” and get a formal ultrasound
Main objective: literature review of ED
ultrasound
AAA
Pregnancy
4 Primary Indications
Cardiac
FAST
FAST: objectives
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What is the learning
curve for FAST?
Can surgeons use
FAST accurately?
Can emergency
physicians use FAST
accurately?
FAST: general comments
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Sensitivity is very dependant on the gold
standard
FAST done by RADIOLOGISTS
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Laparotomy as gold standard
Sensitivties 93-97%
 Specificities 99-100%
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CT as gold standard
Sensitivity 89%
 Specificity 99%
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FAST: variable sensitivity
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Melanson. Emerg Med Clinics 1998
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Reviewed 30+ studies
Summarized studies with > 250 scans
Sensitivities ranged from 70-99%
Specificities ranged from 95-99%
FAST: variable sensitivity
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Branney. J. Trauma. 1995
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Used CAPD patients and looked at sensitivity
with various volumes of dialysate
FAST sensitivity clearly varies with volume of
intraperitoneal fluid
FAST: learning curves
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Gracias. American Surgeon: showed correlation
of sensitivity with experience
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Minimal (<30exams): sensitivity 59%
Moderate (30-100): sensitivity 88%
Extensive (>100): sensitivity 100%
Shackford. J Trauma. 1999
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Prospective, N=241
Surgeons with 8hr training and 10 supervised exams
Gold standard problems
FAST learning curves: Shackford 1999
Error rates
18
16
14
12
10
8
6
4
2
0
Exams 1-5
Exams 6-10 Exams11-15 Exams 16-20 Exams 20-25
FAST: surgeons
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Rozycki. J Trauma
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Prospective, N=476
32hour training (some had more)
Gold standard problems: CT, lap, DPL, or
serial exams!!!!
Sensitivity 79%, Specificity 96%, Accuracy
92%
Compared to radiology review of still images
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Accuracy 90%, 5% technically inadequate
FAST: 6 prospective studies
Study
Size
Training
Sens. %
(C.I.s)
Spec.%
(C.I.s)
Accurracy
(C.I.s)
Mandavia
2000
N=198
16 hrs
86
(61-93)
100
(94-100)
97
Lanoix
2000
N=44
4hrs
94
(68-97)
93
(75-99)
93
Jones
2003
N=122
unclear
?8hrs
72
(53-86)
97
(91-99)
90
(83-95)
Rowland
2001
N=66
3 days
64
(31-89)
85
(73-94)
82
(70-90)
Ma
1995
N=245
10hr +20
exams
86
99
98
Vassiliadis
2003
N=140
variable
70 (58-97)
98 (95-100) 91 (86-96)
FAST: 6 prospective studies
Study
Size
Training
Sens. %
(C.I.s)
Spec.%
(C.I.s)
Accurracy
(C.I.s)
Mandavia
2000
N=198
16 hrs
86
(61-93)
100
(94-100)
97
Lanoix
2000
N=44
4hrs
94
(68-97)
93
(75-99)
93
Jones
2003
N=122
unclear
?8hrs
72
(53-86)
97
(91-99)
90
(83-95)
Rowland
2001
N=66
3 days
64
(31-89)
85
(73-94)
82
(70-90)
Ma
1995
N=245
10hr +20
exams
86
99
98
Vassiliadis
2003
N=140
variable
70 (58-97)
98 (95-100) 91 (86-96)
FAST: emergency physicians
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Mandavia. Acad Emerg Med 2000
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Prospective, total N=1138, FAST N=198
Training = 16 hr session
Gold standard = over-read by ED physician
with “extensive” ultrasound training
Results
Sensitivity 86% (61-93)
 Specificity 100% (94-100)
 Accuracy 97%
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FAST: emergency physicians
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Ma. J Trauma. 1995
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Prospective, N=245
Training = 10 hrs + 20 exams
Gold standard problems: CT, DPL, lap, clinical
observation
Also had “surgical sonographer” overread
Results: sensitivity 86%, specificity 99%, accuracy
98% (NO confidence intervals)
Compared to “surgical sonographer”: agreement with
ER interpretation in 95%
FAST: conclusions
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FAST likely takes longer to learn
Emergency physicians can achieve high specificity
FAST done by Radiology is approximately 90% sensitive
Emergency physicians have been shown to be accurate
when interpretation is compared to experienced
ultrasonographer
Emergency physicians have NOT been shown to
achieve high sensitivity
INTERPRET A
NEGATIVE SCAN WITH CAUTION!!
Final Recomendations
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SAEM/CAEP guidelines
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Targets for our scans
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Training of an introductory course + 50 proctored
exams is reasonably supported by the literature
FAST may be the one exception: we should consider
further training in FAST
Accurracy 95%
Technically limited scans < 5-10%
High specificity four all four primary indications ---------------> be aware of this …….
Final Recommendations
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Pregnany
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Definitive IUP ---------- r/o ectopic
No definitive IUP --------- get a formal u/s
No AAA --------- scan if still suspicious
No effusion ------ echo if still suspicious
No free fluid ------- CT scan when stable
Questions?
Comments?