Thoracic Aortic Aneurysms
Abdominal Aortic Aneurysm (AAA)
Diff: renal colic, diverticulosis, GI hemorrhage, acute MI and back pain
Most are infrarenal (90%)
Normal aorta is 2 cm,>3 cm is AAA
Family history is a strong predictor
Pain, sense of abd fullness, pulsations
Should not feel pulsations to the R of the umbilicus(this is where aorta bifurcates as well)
Livedo reticularis-cyanotic, cool, pale, painful toes
Can compress adjacent structures or fibrose
Rupture-pain, hypotension, pulsatile abd mass, syncope
Studies: x-ray useless, bedside UTS or CT (do not need contrast to see aneurysm, might need it to see rupture, but in the right setting, aneurysm=rupture)
Aortoenteric fistula
Presents as GI bleeding
Aortovenous-bruit, high output cardiac failure
Appears on radiograph, UTS, CT
T+C 10 units if rupture
Complications post repair-graft infxn, fistula, anastomic aneurysm
Case 3: 69 year old male is brought to the ED by paramedics for acute LLQ pain and hematuria. The pain is 7/10, colicky, sharp, and worse when standing. He also complains of mild SOB and sweating off and on today but denies cough, CP, fever, nausea, vomiting or diarrhea. PMH is significant for CAD, CHF, CVA’s, HTN, NIDDM, and an appendectomy. His medications include glyburide, HCTZ, Lopressor, and K+.
Physical exam: WNWD male “relaxed, pale, and diaphoretic”. HR 94, BP 127/84, RR 26, T 37.1°C. RESP: mild right basilar crackles, CV: irregular without murmurs, GI: obese and soft with moderate LLQ tenderness, EXT: no edema and normal pedal pulses. BACK: no CVA tenderness. Rectal: 2+ prostate, heme negative brown stool.
Differential Diagnosis
· AAA
· Aortic dissection
· Diabetic ketoacidosis
·
Cardiac ischemia
· Mesenteric Ischemia
· Nephrolithiasis
· Pancreatitis
Additional information:
Genital exam: normal
EKG: Atrial fibrillation without signs of ischemia
UA: WBC 3, RBC 1
Chest X-ray: Cardiomegally, mild CHF
Bedside glucose: 190
Next diagnostic test of choice? Doesn’t Nephrolithiasis cause more than 1 RBC on urinalysis?
In the ED we always need to rule out life threatening causes. Given the non-specific nature of this patient’s pain and risk factors one must consider the three vascular abdominal emergencies in the elderly: a leaking AAA, mesenteric ischemia, and myocardial infarction.
In this case the treating physician suspected nephrolithiasis and ordered a KUB and then an IVP. What is the role of abdominal x-rays in the work up of abdominal pain? Is a KUB a good screening x-ray or should an “abdominal series” be ordered?
Abdominal Radiographs in Patients with Abdominal Pain
· An “abdominal series” should at least include upright chest in addition to supine abdomen to look for free air under the diaphragm.
· Suspected pathology indications:
1) Perforation
2) Obstruction
3) Volvulus
· A KUB is not a good screening x-ray even for nephrolithiasis. Even though textbooks state that 90% of kidney stones are visible on radiograph (outside of the patient), less than 10% can be seen on prediagnosis x-ray (with in the patient).
The KUB interpreted by the radiologist while the IVP was being done showed a large calcified AAA.
Next move?
Stat Surgical Consult.
Hospital course. Over the phone the surgical consult suggested that an abdominal CT scan be performed to delineate whether or not the aneurysm was ruptured (because repair of symptomatic, but not ruptured AAA has a much lower mortality if performed electively rather than emergently). Twenty minutes later a CT scan confirmed a ruptured AAA. The patient became hypotensive with a SBP in the 60’s and 70’s. He received 4 liters of saline and 4 units of O negative blood in an effort to “stabilize” him so he could be taken to surgery. Although his blood pressure transiently increase, he arrested as he was being wheeled into the OR and could not be resuscitated.
Abdominal Aortic Aneurysm
Pathophysiology:
· Localized dilatation of aorta involving all layers of vessel wall
Epidemiology:
· 2-4% prevalence over age 50
· 10% prevalence over age 80
· Five times more common in males
Etiology:
· Cause currently unknown
· Associated with long history of hypertension and atherosclerosis
Signs/Symptoms:
· Without rupture or leakage, most are asymptotic
· With rupture
1) Abdominal or back pain
2) Hypotension
3) Exam may be misleading: often without significant tenderness, may not palpate a pulsatile mass: cannot rule out AAA base on exam (Lederle).
Laboratory:
· Not helpful in excluding diagnosis
· Hematuria is common and does not help differentiate AAA from nephrolithiasis (7/15 microscopic and 6/15 gross hematuria in study by Pomper 1995 where as Bove found that 33% of patients with CT documented nephrolithiasis had a urinalysis with fewer than 5 RBC and 11% had no RBC).
Radiology:
· Plain film radiographs
1) Suggests AAA 60% of the time
2) Best view is lateral lumbar spine file
3) Should never be used to rule out AAA
· Ultrasound:
1) Can diagnose the presence or absence of an AAA
2) Will not differentiate whether or not AAA is leaking or ruptured
3) Allows for continued careful monitoring of patient
4) Operator dependent, however a recent study has shown ED physicians to be very (100%) accurate for detecting AAA with only 2/68 scans being indeterminate.(Kuhn)
· CT Scan of abdomen
1) Diagnoses the AAA if it is leaking or ruptured
2) Patient must leave the department
3) Less operator dependent
4) Excellent at diagnosing other pathology
5) Scans for nephrolithiasis will diagnose AAA (Nachmann)
· Angiography
1) Less sensitive than other modalities and more invasive
2) Main role is preoperative evaluation of elective AAA repair
3) No role in emergency evaluation of suspected leaking AAA
Treatment:
· For leaking AAA
1) Immediate surgical consult
2) Fluid/blood transfusion: controversial, some data suggests “hypotensive hemostatis” and withholding fluids and blood until SBP drops below 50mmHg. (Bickell)
3) Mortality 100% without surgery; 50% with surgery overall: mortality greater when rupture occurs into abdominal cavity (Satta 1998)
4) Even symptomatic, but radiographically “unruptured” AAA should be operated on emergently and do not have a higher mortality when performed emergently than electively.(0/9 versus 5/18 in one series, Adam)
5) One recent study found that emergency surgery in patients over 80 years of age only prolonged life by an average of 1 week. (Robinson 1997)
6) Cutting Edge: Emergently Placed Endovascular Grafts
a) Landmark Study: Ohki and Veith
b) Used a transbrachial balloon to achieve hemostasis in patients with 25 patients with ruptured AAA
c) 20 patients were stented with a “one-size-fits-all” graft; 5 needed open laparotomy
d) 23/25 survived to hospital discharge
e) Amazing results in study that included unstable patients
f) Currently limited to major vascular surgery center: should be available more broadly in 2 years
· For asymptomatic non-ruptured AAA
1) Refer for elective surgical or transfemoral repair
2) Treatment of even small aneurysms shown to improve survival in almost all patients: even octogenarians
3) Elective repair mortality: 1-5%
Teaching Points:
1) Always consider the diagnosis of AAA first in vasculopaths with signs and symptoms of nephrolithiasis.
2) Utilized helical CT to diagnose nephrolithiasis rather than IVP when available.
3) For patients with suspected AAA rupture or leaking: Call a surgeon and ready the OR immediately; don’t delay the call for diagnostic studies.
References
Adam DJ, Bradbury AW, Stuart WP, et al. The value of CT in the assessment of suspected ruptured AAA. J Vasc Surg 1998;27:431-437.
Attard AR, Corlett MJ, Kidner NJ, et al. Safety of early pain relief for acute abdominal pin. BMJ 1992;305:554-556.
Balthazar EJ, Yen BC, Gordon RB. Ischemic colitis: CT evaluation of 54 cases. Radiology 1999;211:381-388.
Bickell WH, Wall MJ, Pepe PE, et al. Immediate versus delayed fluid resuscitation for hypotensive patients with penetrating torso injuries. N Engl J Med 1994;331:1105-1109.
Blum U; Langer M; Spillner G; Mialhe C; et al. Abdominal aortic aneurysms: preliminary technical and clinical results with transfemoral placement of endovascular self-expanding stent-grafts. Radiology, 1996 Jan, 198(1):25-31.
Brennan DF. Ectopic Pregnancy- Part I: Clinical and Laboratory Diagnosis. Academic Emergency Medicine 1995;2:1081-1088.
Brennan DF. Ectopic Pregnancy- Part II: Diagnostic Procedures and Imaging. Academic Emergency Medicine 1995;2:1090-101097.
Buckley RG, King KJ, Disney JK, et al. Serum progesterone testing to predict ectopic pregnancy in symptomatic first-trimester patients. Ann Emerg Med 2000;36:95-100.
Castellone JA, Powers RD. Ischemic Bowel Syndromes: A Comprehensive, State-of-the-Art Approach to emergency diagnosis and management. Emergency Medicine Reports 1997;18:189-200.
Casto MA, Shipp TD, Casto EE, et al. The use of helical CT in pregnancy for the diagnosis of acute appendicitis. Amer Jo Obstet Gyn 2001;184:954-957.
Chou CK, Tsai TC. Small bowel volvulus. Abdom Imaging 1995;20:431-435.
Dart RG, Kaplan B, Cox C. Transvaginal ultrasound in patients with low β-hCG values: how often is the study diagnostic? Ann Emerg Med 1997;30:135-140.
Dart RG, Dart L, Mitchell P, Berty C. The predictive value of endometrial stripe thickness in patients with suspected ectopic pregnancy who have an empty uterus at ultrasonaography. Academic Emergency Medicine 1999;6:602-609.
Fenjo G. Acute abdominal disease in the elderly. Am J Surg 1982;143:751-754.
Funaki B, Grosskreukz SR, Funaki CN. Using unenhanced helical CT with enteric contrast material for suspected appendicitis in patients treated at a community hospital. AJR 1998;171:997-1001.
Gore RM, Miller FH, Pereles FS, et al. Helical CT in the evaluation of the acute abdomen. 2000;174:901-913.
Gurleyik E, Gurleyik G. Small Bowel Volvulus: a common cause of mechanical obstruction in our region. Eur J Surg 1998;164:51-55.
Hallan S, Asberg A. The accuracy of C-reactive protein in diagnosing acute appendicitis a meta-analysis. Scan J Clin Lab Invest 1997;57:373-380.
Hörmann M, Paya K, Eibenberger K, et al. MR Imaging in children with nonperforated acute appendicitis. Amer Jo Radiology 1998;171:1998.
Klempnauer J; Grothues F; Bektas H; Pichlmayr R. Long-term results after surgery for acute mesenteric ischemia. Surgery 1997 Mar, 121(3):239-43.
Kuhn M, Bonnin RLL, Davey MJ, et al. Emergency department ultrasound scanning for abdominal aortic aneurysm: accessible, accurate, and advantageous. Ann Emerg Med 2000;36:219-223.
Lederle FA, Simel DL. Does this patient have abdominal aortic aneurysm? JAMA 1999;281:77-82.
Lee JS, Stiell IG, Wells GA, et al. Adverse outcomes and opiod analgesic administration in acute abdominal pain. AEM 2000;7:980-987.
Leo PJ, Simonain HG. The role of serum phosphate level and acute ischemic bowel disease. Amer Jo of Emerg Med 1996;14:??
Lim HK, et al. Diagnosis of acute appendicitis in pregnant women: values of sonography. Am J Roent 1992;159:539-
Loh YH, Dunn GD, CT features of small bowel volvulus. Aust Radio 2000;464-467.
LoVecchio F, Oster N, Sturmann K, et al. The use of analgesics in patients with acute abdominal pain. J Emerg Med 1997;15:775-779.
Lowe LH, Penney MW, Stein SM, et al. Unenhanced limited CT of the abdomen in the diagnosis of appendicitis in children: comparison with sonograpy. AJR 2001;176:31-35.
Mader TJ. Acute diverticulitis in young adults. Journal of Emergency Medicine, 1994 Nov-Dec, 12(6):779-82.
Maenza RL, Smith L, Wolfson AB. The myth of the fecalith. Amer jo Emerg Med 1996;14:394-397.
Mahadevan M, Graff L. Prospective randomized study of analgesic use for ED patients with RLQ abdominal pain. Amer Jo Emerg Med 2000;18:753-756.
Nachmann MM, Harkaway RC, Summerton SL, et al. Helical CT scanning: the primary imaging modality for acute flank pain. Amer Jo Emerg Med 2000;18:649-652.
Ohki T, Veith FJ. Endovascular grafts and other image-guided catheter-based adjuncts to improve the treatment of ruptured aortoiliac aneurysms. Ann Surg 2000;232;
Orr RK, Porter D, Hartman D. Ultrasound to evaluate adults for appendicitis: decision making based on meta-analysis and probabilistic reasoning. Acad Emerg Med 1995;2:644-650.
Pace S, Burke TF. Intravenous morphine for early pain relief in patients with acute abdominal pain. Acad Emerg Med 1996;3:1086-1092.
Pomper SR, Fiorillo, MA; Anderson, CW; Kopatsis, A.Hematuria associated with ruptured abdominal aortic aneurysms . Int Surg 1995;80:261.
Rao PM, Rhea JT, Novelline et al. Effect of computed tomography of the appendix on treatment of patients and use of hospital resources. New Eng Jo of Med 1998;338:141-146.
Rao PM; Rhea JT; Novelline RA. Sensitivity and specificity of the individual CT signs of appendicitis: experience with 200 helical appendiceal CT examinations.
Journal of Computer Assisted Tomography, 1997 Sep-Oct, 21(5):686-92.
Rao PM, Rhea JT, Rao JA, Conn AKT. Plain abdominal radiography in clinically suspected appendicitis: diagnostic yield, resource use, and comparison with CT. American Journal of Emergency Medicine, 1999;17:325-335.
Rao PM; Rhea JT; Novelline RA; McCabe CJ. The computed tomography appearance of recurrent and chronic appendicitis. American Journal of Emergency Medicine, 1998 Jan, 16(1):26-33.
Rao PM; Rhea JT; Novelline RA; McCabe CJ; Lawrason JN; Berger DL; Sacknoff R.Helical CT technique for the diagnosis of appendicitis: prospective evaluation of a focused appendix CT examination. Radiology, 1997 Jan, 202(1):139-44.
Rao PM. CT for suspected appendicitis. AJR 1999;1447-1448. (Letter)
Rao PM, Rhea JT, Novelline RA, et al. Helical CT with only colonic contrast material for diagnosing diverticulitis: Prospective evaluation of 150 patients. AJR 1998;170:1445-1449.
Regan F, Karlstad RR, Magnuson TH. Minimally invasive management of acute superior mesenteric artery occlusion: combined urokinase and laparoscopic therapy. Amer Jo of Gastroenterology 1996;91:1019-1021.
Rha SE, Ha HK, Lee SO, et al. CT and MR imaging findings of bowel ischemia from various primary causes. Radiographics 2000;20:29-42.
Robinson D, Englund R, Hanel KC. Treatment of abdominal aortic aneurysm disease in the 9th and 10th decades of life. Australian and New Zealand Journal of Surgery 1997;67:640-642.
Rothrock SG. Misdiagnosis of appendicitis in nonpregnant women of childbearing age. J Emerg Med 1995;13:1
Rothrock SG. Overcoming limitations and pitfalls in the diagnosis of acute appendicits. Emergency Medicine Reports 1992;13:41-52.
Satta J, Leaearea E, Reinilea, et al. Rupture type determines the outcome for ruptured AAA patients. Annnals Chirurgiae et Gynaecologiae 1997;86:24-29.
Schnieder TA, Longo WE, Ure T, Vernava AM. Mesenteric Ischemia: acute arterial syndromes. Dis Colon Rectum 1994;37:1163-1174.
Snyder BK, Hayden SR. Accuracy of leukocyte count in the diagnosis of acute appendicitis. Ann Emerg Med;33:565-574.
Spivak H; Weinrauch S; Harvey JC; Surick B; Ferstenberg H; Friedman I. Acute colonic diverticulitis in the young. Diseases of the Colon and Rectum, 1997 May, 40(5):570-4.
Stovall TG, Kellerman AL, Ling FW, et al. Emergency department diagnosis of ectopic pregnancy. Ann Emerg Med 1990;19:1098-1103.
Taourel P, Deneuville M, Praden J, et al. Acute mesenteric ischemia: diagnosis with contrast enhanced CT. Radiology 1996;199:632-636.
Tilden FF, Powers RD. Ectopic Pregnancy: avoiding missed diagnosis and reducing morbidity. Emergency Medicine Reports 1996;17:199-205.
Vermeulen B, Morabia A, Unger PF, et al. Acute appendicitis: influence of early pain relief on the accuracy of clinical and US findings in the decision to operate a randomized trial. Radiology 1999;210:639-643.
Vignati PV; Welch JP; Cohen JL. Long-term management of diverticulitis in young patients. Diseases of the Colon and Rectum, 1995 Jun, 38(6):627-9.
Wagner JM, McKinney WP, Carpenter JL. Does this patient have appendicitis? Jama 1996;276:1589-1594.
Weltman DI, Yu J, Krumenachker J, et al. Diagnosis of acute appendicitis: comparison of 5- and 10-mm CT sections in the same patient. Radiology 2000;216:172-177.
Wise SW, Labuski MR, Kasales CJ, et al. Comparative assessment of CT and Sonographic Techniques for appendiceal imaging. AJR 2001;176:933-941.
Zoltie M, Cust MP. Analgesia in the acute abdomen. Annals of the Royal College of Surgeons of England 1986;68:209-210.
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