fales & nakajima aortic emergencies
TRANSCRIPT
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Aortic EmergenciesCarrie Fales, MD
Steven Nakajima, PharmD
No Financial Disclosures
ED or No ED? Objectives
AAA and Aortic dissections Overview
Classification/Pathophysiology
Diagnostics
Management
Disposition
Who is in the audience?
Are you a:
A. Nurse
B. Paramedic
C. Physician
D. NP or PA
E. Respiratory therapist
F. Pharmacist
G. Other
Aortic Emergencies
Abdominal Aortic Aneurysm (AAA)
Aortic Dissection
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https://my.clevelandclinic.org/health/articles/heart-blood-vessels-aorta/aortic-aneurysm-aortic-dissection?view=print https://my.clevelandclinic.org/health/articles/heart-blood-vessels-aorta/aortic-aneurysm-aortic-dissection?view=print
Vessel AnatomyIntima = endothelial layer
Media = smooth muscle; elastin, collagen, and proteoglycans
Adventitia = collagen
Aneurysm vs. Dissection DefinitionsAneurysm
Focal dilatation in an artery
Greater than 1.5x normal diameter
True aneurysms have expansion of all layers of vessel wall
False aneurysms/pseudo aneurysms contained only by adventitia or surrounding soft tissue, ruptured media
Dissection
Blood entering media and splitting the layers of the aorta
Avoid ‘dissecting aneurysm’ terminology
Abdominal Aortic Aneurysm (AAA) Classification Classification of abdominal aortic aneurysms in reference to renal arteries Suprarenal, Pararenal, Juxtarenal, Infrarenal
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Abdominal Aortic Aneurysm
90% of AAA originate below renal arteries Due to rebound systolic pressure forces and turbulent flow
at bifurcation causing mechanical stresses
Low elastin content in this region
Area more prone to atherosclerosis
Comparable to proximal aorta and bicuspid valve
Abdominal Aortic Aneurysm
Defined as aneurysm at ≥3.0cm
Repair considered at ≥5.0cm
After age 50 years, the normal diameter of the infrarenalaorta 1.5 cm in women 1.7 cm in men
Risk of rupture directly related to size < 4 cm aneurysm, < 2% risk per year 4-5 cm, 1-5% 5-6 cm, 3-15% 6-7 cm, 10-20% > 7 cm, 20-50%
Risk Factors Male
Smoking history
Family history
Chronic obstructive pulmonary disease (COPD)
Previous aneurysm repair or peripheral aneurysm (popliteal or femoral)
Coronary artery disease
Hypertension
Marfan syndrome, Ehlers-Danlos syndrome, and collagen-vascular diseases
Mycotic aneurysm
Cystic medial necrosis
Arteritis
Trauma
Anastomotic disruption producing pseudo aneurysms
Smoking
ED or NO ED? Abdominal Aortic Aneursyms
Classic triad of back/abdominal/flank pain, hypotension, and palpable pulsatile mass only present 30% of the time
Most AAAs asymptomatic until time of rupture
15,000 deaths per year in US
Up to 30% of patients in ED misdiagnosed Common renal colic, diverticulitis, GI bleed
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Pre hospital Care
Advanced Life Support level care
IV access
EKG and cardiac monitoring
Treat hypoxia with oxygen
Treat hypotension with IVFs
Thorough neurologic exam
Physical Exam
Thorough physical exam- abdominal, neuro, cardiac, pulmonary
Abdominal bruit 5-10%
Palpation of pulsating mass Neither sensitive or specific
Size dependent
Patient dependent
Differential Diagnosis
Acute coronary syndrome
Cholecystitis, cholelithiasis, choledocholithiasis
Pancreatitis
Peptic ulcer disease, gastritis, GERD
GI bleed
Musculoskeletal back pain
Renal colic
Diverticulitis
Evaluation
BMP
CBC
Coagulation studies
Type and screen/cross
Also consider cardiac enzymes, LFTs, lipase, UA with other diseases in differential
EKG
Diagnostic Studies
X-ray Rarely can see calcification
Used to identify alternative diagnoses
Diagnostic Studies
CT
Nearly 100% sensitive and specific
Can detect extra luminal blood Retroperitoneal hemorrhage identification 77-
100% sensitive
Helpful for surgical planning
Radiation
Time consuming
Not ideal for unstable patient
IV contrast not necessary but does provide more information
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Diagnostic Studies
Ultrasound
ED bedside US ideal
Advantages Readily available Very sensitive and specific Lack of radiation
Disadvantages Operator dependent Inadequate to identify retroperitoneal blood, most
common area of AAA rupture
Bedside Ultrasound
Use 3.5 MHz curvilinear transducer
Measure outer wall to outer wall
Measure proximally and distally
Transverse (9 o’clock) and sagittal/longitudinal (12 o’clock) planes
If AAA found, look for free fluid with FAST
Biggest hurdles Bowel gas Obesity IVC vs. aorta
Transverse Proximal
Transverse Distal
Sagittal/Longitudinal Proximal
Sagittal/Longitudinal Distal
Treatment and Disposition
Surgical emergency
Early surgical evaluation and involvement
Resuscitate hypotensive patients with blood products
Treat hypertension with beta blockers
Question #1
The majority of isolated AAAs are infrarenal in location.
a. True
b. False
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Question #1- Answer
The majority of isolated AAAs are infrarenal in location.
a. True
b. False
Question #2
All of the following are risk factors for aortic aneurysm EXCEPT:
a. Hypertension
b. Age over 65
c. Cigarette smoking
d. Atherosclerosis
e. Diabetes
Question #2- Answer
All of the following are risk factors for aortic aneurysm EXCEPT:
a. Hypertension
b. Age over 65
c. Cigarette smoking
d. Atherosclerosis
e. Diabetes
Question #3
In what percentage of patients presenting with abdominal aortic aneurysm is an alternative, incorrect diagnosis initially made by physicians?
a. 10% b. 30% c. 50% d. 80%
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Question #3- Answer
In what percentage of patients presenting with abdominal aortic aneurysm is an alternative, incorrect diagnosis initially made by physicians?
a. 10% b. 30% c. 50% d. 80%
Question #4
The absence of a pulsatile abdominal mass excludes the diagnosis of aortic aneurysm.
a. True
b. False
Question #4- Answer
The absence of a pulsatile abdominal mass excludes the diagnosis of aortic aneurysm.
a. True
b. False
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Aortic Dissection Aortic Dissection
Subset of acute aortic syndromes Aortic intramural hematoma
Penetrating atherosclerotic ulcer
Aortic dissection
Aortic Dissection
Aortic dissection diagnosis missed in ED setting 16-38% of the time More likely to be missed for walk-in patients compared to EMS
arrived patients
Area for medical risk and litigation
High morbidity and mortality Type A Dissection
1-2% mortality per hour in first 48 hours 50% mortality day three 80% mortality day fourteen
Type B dissection 10-70% mortality at day 30 based on risk factors and medical co-
morbidities
Aortic Dissection
2/3 of aortic dissections are Stanford type A
1/3 of aortic dissections are Stanford type B Approximately 30% will be classified as complicated
dissections radiographic evidence of thoracic aortic rupture (eg, blood
outside the aortic wall)
ischemia involving the viscera, kidneys, spinal cord, or lower extremities
persistent pain
rapid expansion in the distal arch or proximal descending aorta to a total aortic diameter of > 4.5 cm
Classification
Acute vs chronic
14 days of symptoms
DeBakey type I, II, or III
I- ascending aorta, arch, descending aorta
II- only ascending aorta
III- only descending aorta
Stanford A or B
A- any involvement of ascending aorta
B- only descending aorta
Classification
Class 1 – classic aortic dissection: separation of intima from media and/or adventitia with intimal flap
Class 2 – intramural hematoma: hemorrhage within aortic wall without obvious intimal flap
Class 3 – subtle-discrete dissection: localized intimal tear with no dissection flap or medial hematoma
Class 4 – penetrating atherosclerotic ulcer: usually localized to descending aorta with significant atheroma; found usually in the adventitia with localized hematoma or saccular aneurysm. May convert to classic aortic dissection
Class 5 – iatrogenic or traumatic dissection: following cardiac catheterization or cardiac surgery or decelerating chest trauma
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Aortic Dissection
Approximately 10,000 patients in US per year Likely underestimate because of retrospective data and
autopsy data
Most commonly 40-70 year olds
Men 3x more likely than women
Women tend to present later and with worse outcomes
Risk Factors
Hypertension
Cocaine
Pregnancy
Trauma
Congenital: Aortic coarctation, Bicuspid valve, Connective Tissue Disorders- Marfan, Ehlers-Danlos, Turner Syndrome
Iatrogenic: Heart surgery, Aortic valve replacement, Catheterizaiton
ED or No ED? Clinical History
International Registry of Acute Aortic Dissection [IRAD]Hagan PG. JAMA 2000, 283:897
464 patients
12 centers
Database of clinical information
Clinical features, treatment, and outcomes
Classic symtomatology: abrupt and severe chest pain that radiates to back
ripping, tearing sensation
feeling of impending doom
Pre hospital Care
Advanced Life Support level care
IV access
EKG and cardiac monitoring
Treat hypoxia with oxygen
Treat hypotension with IVFs
Thorough neurologic exam
International Registry of Acute Aortic Dissection- History
Male 65.3%
Mean age* 63 years
Type A 62.3%
Hypertension 72.1%
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International Registry of Acute Aortic Dissection- Symptoms
Pain present is 95.5% of patients
Chest pain 72.7%
Anterior chest pain 60.9%
Back pain 53.2%
Abdominal pain 29.6%
International Registry of Acute Aortic Dissection- Pain
Abrupt onset 84.4%
‘Worst pain ever’ 90.6%
Sharp 64.4%
Tearing or ripping 50.6%
Radiating 28.3%
Migratory 16.6%
Physical Exam
Thorough physical exam- neuro, cardiac, pulmonary
Need high index of suspicion
Aortic insufficiency murmur (32%)
Pulse deficit in radial and/or femoral arteries (15%)
Hypertension (49%)
Hypotension (18%)
Check bilateral upper extremity blood pressure A difference of 20 mm Hg between arms is considered positive and can be
suggestive of an aortic dissection However, 20% of the population will have a blood pressure differential
without an aortic dissection
Differential DiagnosisThink about aortic dissection with any chest pain, back pain, abdominal pain, syncope, acute neurologic deficit with pain
Broad differential:
Myocardial infarction/acute coronary syndrome
Pericardial effusion, tamponade, pericarditis
Pneumonia
Esophageal rupture
Pneumothorax
Pulmonary embolism
Stroke
Musculoskeletal
Spinal cord injury
Intra-abdominal process
Evaluation
BMP
CBC
Coagulation studies
Type and screen/cross
Also consider cardiac enzymes, LFTs, lipase, UA with other diseases in differential
D-dimer Multiple studies to use as screening tool but none validated
Diagnostic Studies
EKG Nondiagnostic and not specific or sensitive Q waves
ST abnormalities
T wave abnormalities
No abnormalities
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Diagnostic Studies
Chest x-ray
There is no single radiographic finding that accurately predicts the presence of aortic dissection.
Wide mediastinum 66.1%Abnormal aortic contour 49.6%Pleural effusion 19.2%Wall calcification displacement 14.1%Normal CXR 12.4%
Wide Mediastinum
Abnormal Aortic Contour Calcification
Diagnostic Studies
CT Imaging modality of choice
High sensitivity
Identifies alternative diagnoses
Identifies false lumen and additional anatomy Dissection flap
Extension of flap into great vessels
Signs of rupture
Signs of end organ damage
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Diagnostic Studies
Transesophageal echocardiography Requires experienced operator and operator dependent
Usually requires sedation or anesthesia
Evaluates pericardial effusion, left ventricular dysfunction, aortic insufficiency
John A Elefteriades et al. Open Heart 2015;2:e000169©2015 by British Cardiovascular Society
Branch Vessel Compromise
Myocardial infarction
Stroke
Spinal cord infarction
Mesenteric and renal ischemia
Limb ischemia
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Aortic Valve Dysfunction
Aortic insufficiency
Acute pulmonary edema
Pericardial tamponade
ED or No ED?
Treatment
Pain management
Anti-hypertensive therapy Goal to reduce force on intimal flap
Negative inotropic effect
Goal HR <60 and BP <100-120
dP/dT (derivative of pressure / derivative of time) Concept
dP/dT
Antihypertensives
IDEAL Parenteral medications Short acting (fast onset/off-set)
Easily titrated (IV > oral, SL, IM)
Predictable BP reduction (avoid large drop in BP that causes hypoperfusion)
Favorable side effect profile
Patient-specific
β-BlockersDrug Mechanism Dose ADME Pearls
Labetalol β1-β2-α1 antagonist
(↓ HR, SVR)
Bolus: 10-20mg q10
1-6mg/min
On: 2-5min
Off: 2-6hr
-Precipitous ↓ BP-Fluid overload
Esmolol β1-antagonist
(↓ HR, contractility)
Bolus: 500 µg/kg
50–300 µg/kg/min
On: 60s
Off: 10-20min
-First line in aortic dissection-May bolus with increase-Premixed
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Esmolol
• Primarily decreases HR– Usually for aortic dissection
• Bolus: – 500 mcg/kg over 1 minute
• Infusion: 50-300 mcg/kg/min– Titrate by 50 mcg/kg/min
q5 minutes to BP AND HR– Reduce dose if HR <50
Labetalol
• Bolus: – 5-20 mg over 2 minutes– Boluses generally for
acute ischemic stroke
• Infusion: 1-6 mg/min– Titrate by 1 mg/min q5
minutes to BP AND HR– Reduce dose if HR <50
Calcium Channel Blockers
Drug Mechanism Dose ADME Pearls
Nicardipine
Drug Mechanism Dose ADME Pearls
Nicardipine 2nd GenPeripheral L-type selective CCB
(↓ SVR)
2.5-15 mg/hr
On: 5-15min
Off: 4-6hr
-Cerebral and coronary activity-Fluid overload
Clevidipine 3rd Gen Peripheral L-type selective CCB
(↓ SVR)
1-21 mg/hr On: 2-4 min
Off: 5-15 min
-In lipid = 2 kcal/mL-Esterase-Soy/Egg allergy
Nicardipine
• Infusion: 5 -15 mg/hr– Titrate by 2.5 mg/hr
q5 - 15 minutes to BP goal
• May cause reflex tachycardia– Ensure patient is
adequately β-blocked first
Clevidipine
• Infusion: 1-21 mg/hr– Double dose every 90
seconds, as BP approaches goal may increase dose by less than double
– T1/2= 1 minute
Nitric Oxide Donors
Drug Mechanism Dose ADME Pearls
Sodium Nitroprusside
arterial/veno-vasodilator
0.3-10 µg/kg/min
On: 3s
Off: 1-2 min
-Coronary steal-Cyanide toxicity; avoid in liver/renal- ↑ ICP
Nitroglycerine Venous > arterial vasodilator
5-400 µg/min
On: 2-5 min
Off: 10-20min
-Premixed-Variable response to Δ-HA, flushing-PDEs
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Sodium Nitroprusside
Protect from light!
Titration- very fast onset Start: 0.3 mcg/kg/min
Increase every minute by 0.5 mcg/kg/min
Max dose 10 mcg/kg/min
Monitor for cyanide toxicity Dyspnea, SpO2, AMS
Toxicity of Sodium Nitroprusside
Cyanide
Thiocyanate
Methemoglobin
Disposition
Admission to ICU
Surgical intervention vs. medical management Generally surgical intervention for Type A dissections and
medical management for Type B dissections
Endovascular repair vs. open repair Thoracic endovascular aortic repair (TEVAR)
Question #1
To decrease shear force, which of the following should be the initial medical therapy for aortic dissection?
a. Esmolol
b. Clevidipine
c. Nicardipine
d. Nitroprusside
Question #1- Answer
To decrease shear force, which of the following should be the initial medical therapy for aortic dissection?
a. Esmolol
b. Clevidipine
c. Nicardipine
d. Nitroprusside
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Question #2
Acute aortic syndrome encompasses all of the following EXCEPT:
a. Aortic aneurysm
b. Aortic dissection
c. Intramural hematoma
d. Penetrating atherosclerotic ulcer
Question #2- Answer
Acute aortic syndrome encompasses all of the following EXCEPT:
a. Aortic aneurysm
b. Aortic dissection
c. Intramural hematoma
d. Penetrating atherosclerotic ulcer
Question #3
The Stanford type B dissection refers to:
a. DeBakey type I and II dissection
b. Dissection of the ascending aorta only
c. Dissection of both the ascending and descending aorta
d. Dissection of the descending aorta only
Question #3- Answer
The Stanford type B dissection refers to:
a. DeBakey type I and II dissection
b. Dissection of the ascending aorta only
c. Dissection of both the ascending and descending aorta
d. Dissection of the descending aorta only
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Question #4
All of the following are risk factors for aortic dissection or rupture, EXCEPT:
a. hypertension
b. Marfan syndrome
c. known connective tissue disorder
d. cocaine
e. diabetes
Question #4- Answer
All of the following are risk factors for aortic dissection or rupture, EXCEPT:
a. hypertension
b. Marfan syndrome
c. known connective tissue disorder
d. cocaine
e. diabetes
Thank you
References available upon request