Abdominal aortic aneurysm: Difference between revisions
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==Background== | ==Background== | ||
[[File:AneurysmAortaWithArrows.jpg|thumb|CT reconstruction image of an abdominal aortic aneurysm (white arrows).]] | |||
*Infrarenal diameter >3cm or >50% increase in size of diameter | *Infrarenal diameter >3cm or >50% increase in size of diameter | ||
** | **85% of cases are infrarenal <ref name="NJM"></ref> | ||
*M to F ratio is 4:1 | *M to F ratio is 4:1 | ||
*Rupture Risk | *Rupture Risk | ||
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**>5cm: 25-41% | **>5cm: 25-41% | ||
**Rupture possible at any size, most commonly >5cm | **Rupture possible at any size, most commonly >5cm | ||
**Mortality with rupture: 85-90% <ref name="NJM">Kent, K. Abdominal Aortic Aneurysms. The New England Journal of Medicine. 2014; 371:2101-8. DOI: 10.1056/NEJMcp1401430 </ref> | |||
===Risk Factors=== | ===Risk Factors=== | ||
*Smoking | *Smoking | ||
**Risk factor most strongly | **Risk factor most strongly associated with AAA | ||
**Also promotes the rate of aneurysm growth | **Also promotes the rate of aneurysm growth | ||
**Direct relationship between risk and number of smoking years | |||
*Age (prevalence is negligible in age <50yrs) | *Age (prevalence is negligible in age <50yrs) | ||
*Family history | *Family history | ||
*Hypertension | *Hypertension | ||
*Hyperlipidemia | *Hyperlipidemia | ||
*Fluoroquinolone use <ref>P. Wendling for Medscape. FDA Warns of Aortic Aneurysm Risk with Fluoroquinolones. https://www.medscape.com/viewarticle/906867. Accessed 12/26/2018.</ref> | |||
==Clinical Features== | ==Clinical Features== | ||
*Classic triad is pain + hypotension + pulsatile mass | *Classic triad is [[abdominal pain|pain]] + [[hypotension]] + pulsatile mass | ||
**Pain often described as sudden, severe, radiating to back | **Pain often described as sudden, severe, radiating to back, ripping quality | ||
*Syncope (10%) | *[[Syncope]] (10%) | ||
*Signs of [[Retroperitoneal hemorrhage]] | *Signs of [[Retroperitoneal hemorrhage]] | ||
*Massive GI bleed from | *Massive [[GI bleed]] from [[aortoenteric fistula]] | ||
*Pain + AAA = rupture until proven otherwise | *Pain + AAA = rupture until proven otherwise | ||
*Acute abdomen + hypotension = possible rupture | *Acute abdomen + hypotension = possible rupture | ||
*Gross [[ | *Gross [[hematuria]] can be caused by an aortocaval fistula (very rare) | ||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
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==Evaluation== | ==Evaluation== | ||
[[File:AAA.png|thumb|AAA]] | [[File:AAA.png|thumb|AAA]] | ||
[[File:AAA_with_Thrombus.gif|thumbnail|Ultrasound of AAA with Thrombus (click to view).<ref>http://www.thepocusatlas.com/aorta-1/</ref>]] | |||
[[File:AneursymCTMark.png|thumb|Abdominal aortic aneurysm seen on CT with a small area of remaining blood flow (white).]] | |||
[[File:Sagital aaa.jpg|thumb|Sagital reconstruction of aortic aneurysm]] | |||
*[[Aortic ultrasound|Ultrasound]] | *[[Aortic ultrasound|Ultrasound]] | ||
**~100% sensitive for increased diameter | **~100% sensitive for increased diameter | ||
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==Management== | ==Management== | ||
===Rupture=== | ===Rupture=== | ||
[[File:RupturedAAA.png|thumb|Ruptured AAA with an open arrow marking the aneurysm and the closed arrow marking the free blood in the abdomen.]] | |||
*Do not waste time in ED trying to "stabilize" patient | *Do not waste time in ED trying to "stabilize" patient | ||
*Immediate surgery consultation/ go to OR | *Immediate surgery consultation/ go to OR | ||
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***Consider allowing for permissive hypotension (SBP 80-100) in conscious patient | ***Consider allowing for permissive hypotension (SBP 80-100) in conscious patient | ||
**[[Pressors]] | **[[Pressors]] | ||
***[[ | ***[[Norepinephrine]] 0.05mcg/kg/min IV; titrate by 0.02mcg/kg/min q5min | ||
***[[Phenylephrine]] 100-180mcg/min; titrate by 25mcg/min q10min | ***[[Phenylephrine]] 100-180mcg/min; titrate by 25mcg/min q10min | ||
***[[Dopamine]] 5mcg/kg/min; titrate by 5mcg/kg/min q10min | ***[[Dopamine]] 5mcg/kg/min; titrate by 5mcg/kg/min q10min | ||
===Asymptomatic=== | ===Asymptomatic=== | ||
*Prompt vascular surgery outpatient follow-up appt | *Aneurysm > 5 cm: Prompt (within days) vascular surgery outpatient follow-up appt | ||
**Endovascular (75%) vs open repair | |||
*Aneurysm 3-5 cm: Can likely follow up with PCP/surgeon on non-urgent basis | |||
*Screening frequency: | *Screening frequency: | ||
**3-4 cm diameter: 12 months | **3-4 cm diameter: 12 months | ||
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**5-6 cm diameter: 1 month | **5-6 cm diameter: 1 month | ||
*Elective Surgery indicated if: | *Elective Surgery indicated if: | ||
**AAA > 5.5 cm in men | **AAA > 5.5 cm in men <ref name="NJM"></ref> | ||
**AAA > 5 cm in women | **AAA > 5 cm in women <ref name="NJM"></ref> | ||
**increase in size > 1 cm/year | **increase in size > 1 cm/year | ||
**increase in size > 5 mm/6 months | **increase in size > 5 mm/6 months | ||
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*[[Inflammatory abdominal aortic aneurysm]] | *[[Inflammatory abdominal aortic aneurysm]] | ||
*[[Acute limb ischemia]] - embolism to lower extremities | *[[Acute limb ischemia]] - embolism to lower extremities | ||
*Graft infection | |||
*Endoleak | |||
==Disposition== | ==Disposition== |
Revision as of 23:02, 5 August 2020
Background
- Infrarenal diameter >3cm or >50% increase in size of diameter
- 85% of cases are infrarenal [1]
- M to F ratio is 4:1
- Rupture Risk
- <4cm: low risk for rupture
- 4-5cm: 5 year risk 3-12%
- >5cm: 25-41%
- Rupture possible at any size, most commonly >5cm
- Mortality with rupture: 85-90% [1]
Risk Factors
- Smoking
- Risk factor most strongly associated with AAA
- Also promotes the rate of aneurysm growth
- Direct relationship between risk and number of smoking years
- Age (prevalence is negligible in age <50yrs)
- Family history
- Hypertension
- Hyperlipidemia
- Fluoroquinolone use [2]
Clinical Features
- Classic triad is pain + hypotension + pulsatile mass
- Pain often described as sudden, severe, radiating to back, ripping quality
- Syncope (10%)
- Signs of Retroperitoneal hemorrhage
- Massive GI bleed from aortoenteric fistula
- Pain + AAA = rupture until proven otherwise
- Acute abdomen + hypotension = possible rupture
- Gross hematuria can be caused by an aortocaval fistula (very rare)
Differential Diagnosis
Diffuse Abdominal pain
- Abdominal aortic aneurysm
- Acute gastroenteritis
- Aortoenteric fisulta
- Appendicitis (early)
- Bowel obstruction
- Bowel perforation
- Diabetic ketoacidosis
- Gastroparesis
- Hernia
- Hypercalcemia
- Inflammatory bowel disease
- Mesenteric ischemia
- Pancreatitis
- Peritonitis
- Sickle cell crisis
- Spontaneous bacterial peritonitis
- Volvulus
Lower Back Pain
- Spine related
- Acute ligamentous injury
- Acute muscle strain
- Disk herniation (Sciatica)
- Degenerative joint disease
- Spondylolithesis
- Epidural compression syndromes
- Thoracic and lumbar fractures and dislocations
- Cancer metastasis
- Spinal stenosis
- Transverse myelitis
- Vertebral osteomyelitis
- Ankylosing spondylitis
- Spondylolisthesis
- Discitis
- Spinal Infarct
- Renal disease
- Intra-abdominal
- Abdominal aortic aneurysm
- Ulcer perforation
- Retrocecal appendicitis
- Large bowel obstruction
- Pancreatitis
- Pelvic disease
- Other
Evaluation
- Ultrasound
- ~100% sensitive for increased diameter
- Cannot reliably visualize rupture
- CT
- ~100% sensitive for increased diameter and rupture
- IV contrast is preferred but not essential
Management
Rupture
- Do not waste time in ED trying to "stabilize" patient
- Immediate surgery consultation/ go to OR
- Crossmatch 6 units of pRBC
- Pain control (avoid hypotension)
- Antihypertensives (use with caution, goal SBP 110-120 mmHg or MAP 70-80)[4]
- Labetalol: 20mg IV, then 40-80mg IV q10 min (max 300mg)
- Esmolol: Bolus 500 mcg/kg, then 50-200 mcg/kg/min
- Nitroprusside: 0.3 - 0.5 mcg/kg/min, titrate to max 10 mcg/kg/min
- Controversial
- Too little (ischemia), too much (increased bleeding)
- Consider allowing for permissive hypotension (SBP 80-100) in conscious patient
- Pressors
- Norepinephrine 0.05mcg/kg/min IV; titrate by 0.02mcg/kg/min q5min
- Phenylephrine 100-180mcg/min; titrate by 25mcg/min q10min
- Dopamine 5mcg/kg/min; titrate by 5mcg/kg/min q10min
- Too little (ischemia), too much (increased bleeding)
Asymptomatic
- Aneurysm > 5 cm: Prompt (within days) vascular surgery outpatient follow-up appt
- Endovascular (75%) vs open repair
- Aneurysm 3-5 cm: Can likely follow up with PCP/surgeon on non-urgent basis
- Screening frequency:
- 3-4 cm diameter: 12 months
- 4-5 cm diameter: 6 months
- 5-6 cm diameter: 1 month
- Elective Surgery indicated if:
Complications
- Aortoenteric fistula
- Aortocaval fistula
- Inflammatory abdominal aortic aneurysm
- Acute limb ischemia - embolism to lower extremities
- Graft infection
- Endoleak
Disposition
- Admit to OR in cases of ruptured OR
- Vasc surgery follow up in asymptomatic cases
References
- ↑ 1.0 1.1 1.2 1.3 Kent, K. Abdominal Aortic Aneurysms. The New England Journal of Medicine. 2014; 371:2101-8. DOI: 10.1056/NEJMcp1401430
- ↑ P. Wendling for Medscape. FDA Warns of Aortic Aneurysm Risk with Fluoroquinolones. https://www.medscape.com/viewarticle/906867. Accessed 12/26/2018.
- ↑ http://www.thepocusatlas.com/aorta-1/
- ↑ Reed, K. Aortic Emergencies, EB Medicine. 2006.