Ultrasound - American College of Physicians

Focused Bedside
Ultrasound
Seeing is Understanding
Daryl G Morrical MD, FCCP, FACP
History of Medical Ultrasound
1988 – report on echocardiography
performed by ER physicians
1989 use of thoracic U/S by Lichtenstein
Early 1990’s - FAST exam for trauma
2001 ER guidelines for emergency
ultrasound
2010 Consensus statement from American
Society of Echocardiography and American
College Emergency Physicians
Should a Hand-carried Ultrasound
Machine Become Standard Equipment
for Every Internist?
Decades since any new equipment in
internist’s black bag
Stethoscope, neurologic hammer, otoscope,
ophthalmoscope avail 200 years
Hand carried ultrasound equipment extends
physical exam – cost $9K to $40K
J Alpert, Am J Med Jan 2009
History of Medical Ultrasound
Developed from principles of sonar from
World War I
U/S images abdominal disease published
1958
– Early machines required subject be immersed in
water
1967 report of pleural effusion by U/S
1971 – U/S for hemoperitoneum in patient
with blunt trauma
History of Medical Ultrasound
March 2012 Practice Guidelines for Central
Venous Access from ASA
Small hand-held units now available and
used by multiple specialties
Should a Hand-carried Ultrasound
Machine Become Standard Equipment
for Every Internist?
Cardiac - LV assessment, volume status, valvular
disease, pericardial disease
Vascular disease -carotid, abdominal aortic
aneurysm
Musculoskeletal - joint effusion, tendon injury
Renal system - kidney size, obstruction, volume
status
Endocrine -thyroid nodule, solid vs cystic
GI - ascites, gallstones, splenomegaly
Pulmonary – effusions
Procedural guidance
J Alpert, Am J Med Jan 2009
11/23/2012
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Selected Applications of Point-of-Care Ultrasonography, According to
Medical Specialty
Moore CL, Copel JA. N Engl J Med 2011;364:749-757.
Range of Applications
Critical Care
Vascular ultrasonography
– Vascular access, venous thrombosis
Critical care echo
– LV and RV size and function, pericardial disease
(effusion/tamponade), valvular regurgitation,
fluid status/responsiveness
Making the Case
Critical Care Ultrasound
Pulmonary ultrasound (lung sliding, A lines,
B lines) not being done by others at present
– and pleural ultrasound not fully utilized
Integrates multiple disciplines – would
require vascular tech, abdominal tech, and
echo tech to do critical care ultrasound
Reduces radiation exposure
Reduces need to transport patient
Range of Applications
Critical Care
Pleural ultrasonography
– Effusion, pneumothorax (more sensitive than
CXR – may be similar to CT)
Lung ultrasonography
– Consolidation, air bronchograms,
alveolar/interstitial syndrome
(Chest Oct 2012 U/S in dx and f/u of CAP)
Abdominal ultrasonography
– Hydronephrosis, AAA, bladder obstruction,
ascites, diaphragmatic function
Making the Case
Critical Care Ultrasound
New imaging paradigm – real time
assessment, not static image for later
review by radiology or cardiology
Repeated as illness evolves – extends
physical exam
Complementary to current imaging – goal
directed to answer questions, not organ
based complete studies
Recorded image allows others to view
results and compare with prior findings
Making the Case
Critical Care Ultrasound
Allows rapid assessment of shock states –
differentiate sepsis, CHF, pulmonary
embolism, hypovolemia, pericardial
tamponade (Chest Oct 2012)
Recommended by Agency for Healthcare
Research and Quality and ASA for IJ central
line placement, required by ACGME for ER
residency and pulmonary/critical care
fellowships
11/23/2012
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Making the Case
Critical Care Ultrasound
Improved procedural safety – internal
jugular and subclavian line, thoracentesis
May alter treatment approach in 25 – 50%
of critically ill patients
Patients/families appreciate images and
time spent at bedside
Basic Ultrasound Physics
Ultrasound - sound with frequency >20 kHz
– For clinical purpose usually 2-10 MHz
Speed of propagation 1540 m/sec in soft tissue –
determined by density and stiffness of medium
– 330 m/sec in air
– 1497 m/sec in water
Sound generated by piezoelectric crystals –
transducer produces sound and listens for echo –
deeper structure generates later echo
Basic Ultrasound Physics
Interactions of sound with tissue
– Attenuation
Varies with signal frequency
– High frequency signal gives better resolution but
less penetration
Varies with tissue density
– Attenuation of fluid < fat < muscle < fibrous
tissue < calcifications and bone
– Artifacts
Reverberation, ring down, mirror-image, reflection,
enhancement, attenuation
Comparison of Effectiveness of Hand-
Carried Ultrasound to Bedside
Cardiovascular Physical Examination
2 medical students with 18 hrs echo training
compared to 5 cardiologists physical exam –
standard echo as gold standard
61 patients, 239 abnormalities on echo
Students identified 75% of abnormalities,
cardiologists 49%
93% (student) vs 62% (card) for lesions
causing systolic murmur; 75% vs 16% for
lesions causing diastolic murmur
Basic Ultrasound Physics
American Journal of
Cardiology Oct 2005
Interactions of sound with tissue
– Echo occurs at boundary of 2 materials
with different acoustic impedance
Simple fluid – no echo, black image
Small difference –weak echo, gray image
Large difference, strong echo, white image
Very large – ultrasound totally reflected, unable to see
beyond border (air, bone)
– Reflection, refraction
Angle of surface
Staph sepsis, incidental finding CHF
Enhancement, attenuation
Pt with pneumonia,
incidental finding
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Mirror image Reverberation
Basic (B-Mode) Two-Dimensional Ultrasound Image
Moore CL, Copel JA. N Engl J Med 2011;364:749-757.
Basic Ultrasound Physics
Return signal displays
– Signal amplitude displayed as brightness
(B mode - brightness)
– Signal depth/amplitude on a time plot (M
mode – motion)
Gain
Near field
Far field
Autogain
Depth
Exam type
Caliper
Clip
Save
Freeze
2D
Knobology
Ultrasound Guidance for Vascular Access
Moore CL, Copel JA. N Engl J Med 2011;364:749-757.
11/23/2012
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Thoracic Ultrasound
Air/fluid ratio leads to different
patterns
– Pleural effusion
– Alveolar consolidation
– Alveolar/interstitial syndrome
– Normal lung
– Pneumothorax
Effusion p perforated ulcer
Curtain sign R base
Severe sepsis, CHF
Lung cancer
Severe sepsis
Lung sliding point
Acute pulmonary edema
Amiodarone lung
Lung sliding
CHF , recent MI CHF, chronic effusion
CHF, staph on cultures Severe mitral regurg
22 yo with pneumonia
85 yo with heart failure
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Thora on R,
450 ml
transudate
93 yo with hx
smoking prior to
CABG 1996, afib,
now with
progressive
dyspnea, EF 25%
with mild mitral
insuff, mild -mod
aortic stenosis,
Na 122, creat 1.6
54 yo smoker
with 3 rd episode
hypercarbic resp
failure in 6 weeks
– now basilar
density after
extubation, no
leg clots by
venous
compression
Intubated few days later
despite diuresis with
refractory hypoxemia, BP
70’s p intubation
R base
Post thoracentesis
Pleural results - LDH 99, prot 4.5, WBC
1030 (67% polys)
Needle biopsy pleural nodule –
small cell cancer
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51 yo with 3 yr hx metastatic colon ca, few week
progressive cough and dypsnea
Former smoker with
weight loss
Main carina R main bronchus
Distal L main bronchus
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Images from Yale
Interstitial disease
Lung cancer
Resp failure p C section
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49 yo smoker with few month chest cold with dyspnea, copious
clear sputum, weight loss – presented for bronch with HR 130,
BP 150, severe dyspnea, leg swelling, chest pain
Distal trachea
ESRD, HBP
Septic shock
COPD, edema
11/23/2012
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R base L base
72 yo former smoker with HBP, recent
CABG in setting NSTEMI and
pulmonary edema, transferred from
rehab with leg swelling, renal insuff
BNP 8700
L base
22 with recent pneumonia and iv drug use
R anterior chest L lateral base
L posterior base
67 yo with hx CAD now with
dyspnea and chest discomfort -
cardiology ordered CT after
focused bedside study
After 375 ml thoracentesis
WBC 520, LDH 93, prot 2.6
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R com femoral compression R superficial femoral
R popliteal
59 yo with sudden dyspnea, intubated at home with frothy secretions,
mild mitral regurg by echo last year
Post 4 days heparin Rx Pre treatment
Decreased urine output 36 hours later
despite good BP and partial CXR clearing
11/23/2012
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59 yo nonsmoker with cough, confusion, dyspnea after
laparoscopic cholecystectomy for acute cholecystitis
70 yo with peripheral vascular disease, DM, and now sudden dyspnea
with hypertension after transfusion– no known heart disease
50 yo smoker with untreated heart disease and arrest
while playing drums
Had cricothyroidotomy at outside hospital after
intubation attempts unsuccessful
Transudate
11/23/2012
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81-year-old with small smoking history, chronic atrial
fibrillation on Coumadin, rheumatoid arthritis, episode of C.
difficile colitis 2 months ago, chronic hydronephrosis of the
right kidney now with hypotension and diarrhea
Patient complaint of lower
abdominal fullness p surgery
despite Foley
R common femoral
R kidney
L common femoral
L kidney
Acute renal failure in immobile patient from group home
Gallbladder Peristalsis LUQ
Scan lower abdomen R kidney
R common femoral
Hx recurrent CNS tumor, now
with aspiration pneumonia,
thrombocytopenia and leg
swelling, + HIT screen
Foley catheter, air injected
Scan from prox to distal femoral
11/23/2012
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80 yo with AICD x 6yrs, on warfarin 5 months for DVT, progressive dyspnea
and leg swelling
Before thoracentesis Post thoracentesis – 20 ml
Pleural fluid – WBC 330, 98% lymphs, protein 2.5,
LDH 120, glucose 86
L common femoral
L popliteal
R effusion L effusion
L superficial femoral
85 yo with CHF and prior
parapneumonic effusion
Post thoracentesis
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L effusion
L effusion 6 months later
47 yo former smoker with CHF, weight loss, resected paraesophageal hernia
with partial esophagectomy
Chronic R effusion
Scan through L lung base
Initial bronch April 6, repeat April 11
shown above – partial obstruction L
main, complete occlusion RLL
Post thoracentesis –
pleural rub by exam
R lung base with respiration
L base pre bronch
Post bronch L base
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45 yo with prior stroke, remote necrotizing
pancreatitis/splenectomy, bilat DVT 6 months ago on
warfarin, now with dyspnea several days after fall in shower
Drained 700 ml with thoracentesis –
after reversal coags surgery placed
large bore chest tube- 4800 ml
removed by next morning
L lateral view thorax
Upward diaphragmatic
movement with inspiration
74 yo with persistent resp failure after CABG and post surgery inferior MI
11/23/2012
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80 yo with hypertension
and sudden dyspnea
69 yo smoker with hypotension after
perforated ulcer repair
R thorax
8 days later – still
failure to wean
After hydration
and extubation
R lung base L lung base
72 yo 1.5 ppd smoker with progressive weakness, dyspnea,
mild clubbing fingers, 10 mm pulsus, 7 cm R paratracheal
mass, sodium 118
Bronchoscopy with TBNA - adenocarcinoma
L thorax
Apical 4 view
11/23/2012
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82 yo with obesity, DM, chronic anticoagulation, now with
ascites, renal failure, and cardiopulmonary arrest
700 ml exudative fluid removed from R
Chronic resp failure on warfarin, OSA, new renal
failure, arrested in radiology
52 yo with stroke, hx iv drug use
11/23/2012
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61 yo with pancreatitis, refractory hypotension on dobutrex and
pressors, lactate 20, and arrest x 3 overnight
87 yo with bullous lung disease, CAD , recurrent pneumonia, M avium, afib
on Coumadin, AAA now with fall, rib fractures, and progressive azotemia and
sats high 80’s on 100% high flow O2
Elderly pt with COPD
89 yo nonsmoker with hx HBP and ESRD on dialysis x 3 years, PE diagnosed
4 months ago p drive to Florida, pacer for heart block 11 yrs ago, and now
recurrent Staph bacteremia
11/23/2012
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R kidney
L kidney
R kidney L kidney
92 yo with neurogenic bladder now with oliguria, chills/weakness -minimal cloudy
urine from bladder
Required norepinephrine at 70 mcg/min to maintain BP
WBC 19900, Hgb 12.5 BUN 44. creat 3.9, HCO3 20, lactate 6.4
6 hrs later HCO3 14 , WBC 51200 with 37% bands, essentially anuric
Percutaneous nephrostomy by IR later in day – clear on L, purulent on R
77 yo with stroke, CAD, DM, G tube, coffee ground emesis,
and hypotension with dilated renal pelvis on CT abd
Ovarian cancer with ureteral stent ESRD with polycystic kidney
11/23/2012
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L common femoral R common femoral
L kidney R kidney
Acute renal failure in immobile patient from group home
79 yo with prior pelvic radiation now with confusion, hypotension,
renal failure
75 yo with hx squamous cell lung ca x 2 years on erlotinib –
now with progressive dyspnea, new atrial fibrillation
Foley catheter, air injected
11/23/2012
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Assessment of fluid status
Clinical experience “Making the same mistakes with
increasing confidence over an impressive number of
years” Sceptic's Medical Dictionary -Michael
O'Donnell
30 – 60% of hypotensive pts on mechanical
ventilation show no response to fluid administration
– prediction would be helpful given potential for
harm with excess fluids
Physical exam, vital signs, and static parameters
poorly predictive of response to volume expansion
– CVP, PAOP, LV end diastolic area
Assessment of fluid status
Practical approach – pts with spontaneous
breathing or on ventilator
– IVC < 10 mm or hyperdynamic LV with small end systolic
volume – high probability of fluid response
– IVC > 25 mm – low prob of response
– IVC 10-25 mm - indeterminate
“A line” pattern has 90% specificity for PAOP < 13
and may be used to guide safe fluid administration
– filling pressures uncertain with B lines
IVC variability with sniff reported in outpatient
dialysis population to gauge volume status
(IVCCI > 75% hypovolemic, 40-75% euvolemic, < 40% hypervolemic)
Assessment of fluid status
IVC variability >12% in pts passive on mech vent
with TV 8-10 ml/kg implies responsiveness to fluid
bolus (8 ml/kg)– lower tidal volumes, pt effort, and
arrhythmias decrease utility in clinical practice
Dynamic parameters
– Variation in venous return during ventilation or passive leg
raising to assess whether patient on steep portion of
Starling curve (volume responsive) or flat portion – RV
failure and increased abd pressure may limit validity
– PPV (Pulse pressure variation -art line), SPV (Systolic
pressure variation), SVV (Stroke volume variation - VTI by
Doppler at LVOT), Brachial artery peak velocity variation
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