Risk factors associated with acute lower extremity ischemia after coronary revascularization

PAGE 78

JOURNAL OF VASCULAR NURSING www.mosby.com/vascnurs

SEPTEMBER 2002

Risk factors associated with acute lower extremity ischemia after coronary revascularization Debra Kohlman-Trigoboff, ACNP, Enrique Gongora, MD, Jon Stanford, MD, and Bruce M. Smith, MD

Acute lower extremity ischemia (ALEI) is a recognized complication of coronary revascularization that can lead to emergent lower extremity revascularization, amputation, and death. Patients with correctable coronary artery disease have a high incidence of lower extremity arterial occlusive disease (AOD). But, despite the known high correlation between AOD and coronary artery disease, the status of the lower extremity vasculature in patients undergoing coronary revascularization may be overlooked until the lower extremity becomes profoundly ischemic. Data from a retrospective review of 35,000 coronary revascularization procedures identified 55 patients who developed ALEI, subsequent to their cardiac procedures. Risk factors for ALEI included femoral artery instrumentation, previous coronary revascularization, hemodynamic instability, and documented AOD. Means of identifying patients at risk for ALEI are discussed. (J Vasc Nurs 2002;20:78-83)

Acute lower extremity ischemia (ALEI) is a recognized complication of coronary revascularization that can lead to emergent lower extremity revascularization, amputation, and death.1-5 Individuals with correctable coronary artery disease (CAD) have a high incidence of lower extremity arterial occlusive disease (AOD).6 Despite the known high correlation between AOD and CAD, the objective assessment of the lower extremity vasculature in patients undergoing coronary revascularization may be delayed until the lower extremity is profoundly ischemic. When caring for patients who have undergone coronary revascularization, a cardiovascular nurse will encounter patients who develop ALEI. Little information, however, is available on the prediction, prevention, and early recognition of ALEI. This article reviews the risk factors of patients who present with ALEI after coronary revascularization and discusses key elements of the history and physical examination that, if missed, may predispose patients to ALEI, delay its recognition, or complicate its management. According to the American Heart Association,7 more than 2.6 million open heart procedures and percutaneous therapeutic coronary angioplasties (PTCAs) are performed in the United

From the Washington Hospital Center, Section of Vascular Surgery, Washington, DC. Presented at the Society for Vascular Nursing Nineteenth Annual National Symposium, Minneapolis, MN, April 2001. Debra Kohlman-Trigoboff, ACNP, Washington Hospital Center, Section of Vascular Surgery, 110 Irving St, NW, NA-1041, Washington DC 20010. Copyright © 2002 by the Society for Vascular Nursing, Inc. 1062-0303/2002/$35.00 ⫹ 0 40/1/127737 doi:10.1067/mvn.2002.127737

States alone, but the incidence of symptomatic ALEI after coronary revascularization is unknown. The classic study by Hertzer et al6 in 1984 was the first real documentation of this correlation. In an investigation undertaken with the intent of reducing perioperative myocardial infarctions (MIs) after vascular surgery, Hertzer and his associates performed coronary angiography on 1000 patients (mean age, 64 years) who were under consideration for elective vascular procedures, and they demonstrated severe, correctable coronary disease in 38% of those with lower extremity ischemia. ALEI is defined as a sudden, critical reduction in blood flow to the lower extremity. Clinically, ALEI may present as the persistent presence of a cold (poikilothermic), pallid extremity with the loss of previously palpable pulses or Doppler signals. Pain, paresthesias, and paralysis in the leg may also be present,8,9 although these findings may be difficult to evaluate in an intubated or sedated patient. ALEI in patients who have undergone coronary revascularization may result from pre-existing lower extremity AOD in the setting of arterial injury, thromboembolism, mechanical obstruction, and/or a potential hemodynamic compromise, or venous outflow obstruction. Because of the potentially devastating consequences of ALEI in the setting of coronary revascularization, we undertook a review of our experience of this condition.

METHODS We analyzed the outcomes of patients who developed ALEI after percutaneous coronary angioplasty or open surgical coronary revascularization at the Washington Hospital Center in Washington, DC. Our facility is the largest tertiary facility in the area and is listed in US News and World Report10 as third among the top 10 US hospitals in the performance of cardiovascular procedures. During the review period, this facility averaged 12 open surgical and 18 percutaneous coronary revascularizations daily. After Institutional Review Board approval, a query of our computerized database of approximately 35,000 (13,000 coro-

Vol. XX No. 3

JOURNAL OF VASCULAR NURSING www.mosby.com/vascnurs

PAGE 79

TABLE I

TABLE III

DEMOGRAPHICS OF PATIENTS WITH ALEI

COMMON FINDINGS OF PATIENTS WITH ALEI

Characteristics

N ⴝ 55

Age mean (range) Male White Black Hispanic

66 (33-81) 29 (53%) 38 (69%) 14 (26%) 3 (5%)

TABLE II

Characteristics

N

Prior coronary revascularization Unstable angina Congestive heart failure Acute myocardial infarction Prior history of arterial occlusive disease (AOD) Urgent/emergent coronary revascularization

33 (55%) 24 (44%) 17 (30%) 23 (42%) 29 (53%) 52 (94%)

ATHEROSCLEROTIC RISK FACTORS IN PATIENTS WITH ALEI Hypertension Hyperlipidemia Diabetes mellitus Smoking

42/55 (76%) 31/55 (56%) 28/55 (51%) 27/55 (49%)

nary artery bypass grafting [CABG] procedures and 22,000 percutaneous coronary interventions) coronary revascularization procedures were performed from January 1995 to January 2000, and 55 charts meeting the inclusion criteria for ALEI were identified. These charts were directly reviewed. Data collected from the chart reviews included sex, age, race, risk actors for atherosclerosis, history of prior cardiac interventions, and any previous history of AOD or lower extremity revascularization. The indication, urgency, and types of coronary revascularizations were noted for the patients who developed ALEI. ALEI was defined as the observation of a cold and pallid extremity, or the loss of a previously palpable pulse or Doppler signal. Hemodynamic stability was assessed at the time of the initial vascular consult. The hemodynamically “stable” patient had a normal cardiac index and blood pressure reading without pharmacologic or intra-aortic balloon pump (IABP) support. Hemodynamic instability was defined as the requirement for intravenous drips of vasopressors or inotropic medications (norepinephrine, epinephrine, dobutamine, milrinone, and dopamine ⬎ 5 ␮g/kg/min) or an intra-aortic balloon pump (IABP) to maintain a normal blood pressure or cardiac index.

RESULTS The 55 patients found to have ALEI represented an incidence of 1.6 episodes of ALEI per 1000 cases. The demographics, atherosclerotic risk factors, and common cardiac and vascular historical and physical findings of patients with ALEI (B.M.S., E.G., D.K.-T., J.S., unpublished data, 2001) are summarized in Tables 1 through 4. The types of coronary revascularizations in the patients with ALEI are depicted in the Figure. The mortality of the patients who developed ALEI after percutaneous coronary

TABLE IV PREVIOUS VASCULAR HISTORY IN PATIENTS WHO DEVELOP ALEI N ⴝ 29/55 Patients (53%) ● Active claudication ● Lower extremity bypass ● Lower extremity amputation

21/29 9/29 5/29

(72%) (31%) (17%)

intervention was less (4/14 patients, 29%) than those after open surgical revascularization (19/41 patients, 46%).

DISCUSSION ALEI is multifactorial in patients with CAD due to the patient’s comorbidities, previous femoral artery instrumentation, and the atherosclerotic changes in the peripheral vasculature. Several researchers1,5,11,12 found that patients with clinical evidence of vascular disease have a higher incidence of periprocedural complications after PTCA and CABG. They attributed the increased morbidity in these patients to their age, smoking, and their multiple medical comorbid conditions (chronic obstructive pulmonary disease, diabetes mellitus, congestive heart failure [CHF], and chronic renal insufficiency). Because atherosclerosis is a systemic illness that will ultimately determine the patient’s outcome, the cornerstone of care of the vascular patient is the evaluation of risk-benefit when determining intervention.13 In treating ALEI in the patients in this series, we frequently encountered incomplete data on the status of the lower extremity vasculature before coronary revascularization, even in patients with identified ALEI risk factors (ie, abnormal pulse findings; history of AOD, such as previous lower extremity bypass; intermittent claudication; critical ischemia; or multiple femoral instrumentations). If the physician and patient decide to undertake an invasive coronary intervention, the following considerations may decrease the incidence of ALEI.

PAGE 80

JOURNAL OF VASCULAR NURSING www.mosby.com/vascnurs

Figure. Types of coronary revascularization in patients with ALEI.

The health history is the key to the diagnosis and treatment process because it lays the foundation for a thorough physical examination.14 Does the patient have any atherosclerotic risk factors such as smoking, diabetes mellitus, hypertension, or hyperlipidemia? The authors’ data showed that approximately 50% of the ALEI group had a history of diabetes mellitus, hyperlipidemia, and smoking. According to Cook,15 smoking increases the risk of vascular procedures since it narrows the arterial wall and can lead to vasoconstriction and hypercoagulation. Hypertension was found by Kantrowitz16 to be a predictor of vascular complications because it leads to accelerated atherosclerosis by causing smooth muscle cell hypertrophy, leading to a decrease in the arterial lumen. The presence of diabetes was a significant factor in chronic limb-threatening lower extremity ischemia in the study done by Thomas17 because it accelerates the atherosclerotic process and causes calcifications in the arterial walls. In addition, the arterial disease pattern of atherosclerosis in diabetic patients primarily involves the tibioperoneal vessels, thus placing them at increased risk for embolization. Hyperlipidemia also plays a key role in atherosclerosis because lipid cells are the major component of arterial plaques. The arterial plaque has the potential to be dislodged as cholesterol emboli after coronary revascularizations.18 Because our data demonstrated that 38% of the patients who developed ALEI after coronary revascularization had symptomatic AOD, it is important to elicit any history of intermittent claudication, critical ischemia with rest pain, and tissue loss or gangrene. In addition, vascular procedures such as lower extremity bypass, aortobifemoral bypass, or repair of a femoral or abdominal aortic aneurysm should be noted. Patients who have had bypass or arterial repairs are prone to the intimal hyperplasia at their anastamoses and acceleration of their arterial disease both proximally and distally to their procedures.18 Prior femoral artery instrumentation is universal in all patients undergoing coronary revascularization, with many patients having multiple femoral artery punctures, which increases the chances of ischemic complications. However, it is the number of arterial instrumentations that is significant. The patient’s history should include the number of times the patient has had instrumentation of the femoral arteries for arteriograms, cardiac catheterizations, or vascular or cardiac interventional procedures (eg, iliac stenting, carotid stenting, and coronary stenting/angioplasties). Interventionalists often enter the patient’s right groin for

SEPTEMBER 2002

the femoral artery puncture; thus, the right femoral, and possibly the iliac arteries, in a patient who has had multiple groin instrumentations are likely to have more scar tissue. The scar tissue can narrow the lumen, making the arteries susceptible for embolic or thrombotic occlusions. Complications from arterial injury have been found to relate to a large arterial sheath size (⬎ 8 French sheath, generally used for PTCAs or atherectomy devices),2,4 the length of the interventional procedure, and poor technique.19 Patients who are subjected to 2 separate groin sticks are at increased risk for arterial damage, embolization, or bleeding at the site of the indwelling catheters.2,5,19,20 Ricci et al4 found a 1% vascular complication rate in diagnostic catheterizations and a 3% vascular complication rate in interventional catheterizations. If the interventionalist performs the diagnostic study separate from the interventional procedure, the patient is subjected to increased arterial injury. Davis et al2 recommend that the catheters should not be left in for use as intravenous or arterial lines, particularly in patients without a normal examination. These catheters can narrow and obstruct the arterial lumen and serve as a medium for thrombus formation that, when removed, may embolize distally in the leg.19 Other risk factors for arterial injury are the patient’s age (⬎ 60 years) and sex (women have a greater incidence of arterial injury than do men).4,17 The authors’ data showed that the average age of the patient with ALEI after coronary revascularization is 66 years, approximately half of which patients are women. Eagle et al21 reported that the greater proportion of patients with vascular disease are women. Some researchers propose that atherosclerosis is unrecognized in women, whereas others find the smaller caliber of arteries in women as the culprit.15 In several studies, women older than 60 years tended to have greater morbidity after coronary artery revascularization.12,17,22-24 The data analysis revealed that 62% (34 of 55 patients) had an acute MI, and 30% (17 of 55 patients) were being treated for CHF. Therefore, the cardiac history is predictive for those patients who may develop ALEI after coronary revascularization. According to Goldman et al,25 a recent MI and CHF were the strongest predictors of adverse cardiac events in procedures done on vascular patients. A low ejection fraction in cardiomyopathy or CHF can compromise perfusion to the lower extremities.9 In addition, one of the most common complications after CABG is atrial fibrillation, which, if uncontrolled or unrecognized, can cause distal embolization of the mural thrombus from the heart.3,17 Because 94% of the ALEI group had undergone emergent coronary revascularization, this finding has emerged as a key element in predicting potential ALEI after coronary revascularization. Higgins26 and Mangano and Goldman27 reported that emergent coronary artery bypass patients were found to have a higher mortality rate than that of elective patients. These findings can be attributed to poorly controlled comorbidities and less experienced staff assisting with the coronary interventions during off-hours. The condition of patients who require emergent coronary revascularization is more likely to be unstable, and these patients require inotropic or vasoconstrictive drugs or the IABP. The authors’ data analysis demonstrates that 60% of the

Vol. XX No. 3

JOURNAL OF VASCULAR NURSING www.mosby.com/vascnurs

PAGE 81

TABLE V KEY VASCULAR ELEMENTS BEFORE CORONARY REVASCULARIZATION History ● History of vascular disease (intermittent claudication, ulcers, gangrene) ● History of vascular surgery (lower extremity bypass, aneurysm repair) ● Previous femoral artery instrumentation or interventional (vascular or cardiac) procedures ● Emergent versus elective procedure ● Prior coronary revascularization ● Low ejection fraction or congestive heart failure ● Atherosclerotic risk factors (smoking, hypertension, diabetes mellitus, hyperlipidemia)

patients with ALEI after coronary revascularization had hemodynamically unstable conditions. Many patients present with lower extremity ischemia simply because their cardiac output or blood pressure measurement is low.8 A definitive vascular assessment should be deferred until the patient’s condition is hemodynamically stable after coronary revascularization. Although sometimes necessary in the unstable patient, the IABP may acutely compromise the lower extremity perfusion secondary to trauma or the creation of an intimal flap or embolization of the arterial plaque when introduced into the artery. The IABP has been associated with vascular complication rates ranging from 12% to 47%.15,16 The absence of appropriate baseline data complicates subsequent management of patients who do develop ALEI, because the physical examination establishes the baseline vascular status before any procedure.18 The pulse examination can be very revealing. Criqui et al28 who studied more than 600 subjects by noninvasive testing found that an abnormal posterior tibial pulse is indicative of large AOD (sensitivity 71.2% and specificity of 91.3%). Patients whose conditions are asymptomatic of vascular disease who have no palpable pedal pulses who undergo coronary artery bypass, have a two-fold increase in hospital deaths.1 More than half of the patients who developed ALEI had documented AOD; more than 70% of these patients had active intermittent claudication. Preprocedural noninvasive testing such as ankle/brachial indices (ABIs), both at rest and after exercise, is an objective measure of the patient’s vasculature. An ABI is the ratio of ankle to arm systolic pressures and is a simple, inexpensive, and accurate method for detecting lower extremity arterial disease. ABIs are a key part of preinterventional or surgical procedures.12 Stoffers et al29 determined that an ABI less than 0.8 suggests that the patient has AOD. However, a limitation of ABIs in diabetic patients is that the tibial vessels may be noncompressible from calcification of the arterial walls. Therefore, toe/brachial indices (TBIs)–the ratio of toe systolic pressures to arm systolic pressures–may be a better objective measure of the diabetic patient’s vascular status since the digital vessels in diabetic patients are generally spared from calcification.8 The key vascular elements of the history and

Physical examination ● Baseline pulse examination ● Arrhythmias ● Presence of tissue loss on lower extremities ● Presence of arterial bruits or thrills ● Ankle-brachial index ⬍0.8 ● Presence of jugular venous distention (JVD) or pulmonary rales-checking for CHF ● Evidence of lower extremity scars

physical examination before coronary revascularization are summarized in Table 5. Early recognition of ALEI leads to simpler management and presumably will lower morbidity and mortality. How does the patient’s postprocedural pulse examination compare with that before the coronary revascularization? Is there a change in the patient’s ABI, or is there a new bruit (a bruit is the noise auscultated from turbulence in an artery and may be the first sign of arterial injury possibly related to an intimal tear or flap created by a catheter).8 Does the patient now have arterial sheaths, arterial lines, pulmonary artery catheters, or an IABP in his or her femoral artery that may be compromising distal perfusion? Is there mottling of the toes? Atheroemboli may have been dislodged during catheterization or femoral artery cannualization during surgery.5,9 What is the patient’s current cardiac output and blood pressure measurements? If the patient requires inotropic agents or vasopressors to maintain his or her cardiac output and blood pressure, the distal vasculature is often compromised from vasoconstriction or shunting of the blood to vital organs.30 Is the patient adequately oxygenated? If the patient is poorly oxygenated, the key organs such as the brain, heart, and kidneys will take what oxygen is available, sacrificing the extremities. If surgical revascularization was performed, the following factors may predispose the patient to ALEI. Mesh et al3 found that patients with vascular disease required greater cross-clamp time (the time needed to clamp the aorta during surgery [⬎ 63.1 ⫾ 25.3 minutes]) and pump times (the time a patient undergoes cardiopulmonary bypass [⬎ 108.3 ⫾ 42.2 minutes]), secondary to longer, more difficult procedures than patients without vascular disease, thus increasing their morbidity and mortality. The longer the lower extremities are not perfused, the more susceptible they are to becoming ischemic. Other means of decreasing perfusion to the leg are suggested by Goldsborough,31 who found that legs wrapped with Ace bandages or Coban did not heal as well and often became ischemic, possibly relating to the reduction of bloodflow in an already compromised leg. The key vascular elements of the history and physical examination, both before and after coronary revascularization, are listed in Tables 5, 6, and 7.

PAGE 82

JOURNAL OF VASCULAR NURSING www.mosby.com/vascnurs

SEPTEMBER 2002

TABLE VI KEY VASCULAR ELEMENTS AFTER CORONARY REVASCULARIZATION History ● Intraoperative/intraprocedural complications ● Use of intra-aortic balloon pump (IABP) ● Total cross-clamp time ● Hemodynamic status during procedure ● Use of compression on the lower extremities

Physical examination ● Change in pulse status, noting bruits or thrills ● Ankle-brachial indices less than those at preprocedure ● Presence of indwelling femoral lines ● Postprocedural hemodynamic instability ● Poor oxygenation

TABLE VII RISK FACTORS FOR ALEI AFTER CORONARY REVASCULARIZATION History ● Inadequate preprocedural history ● Documented AOD ● Previous femoral artery instrumentation ● Severe CAD (presence of CHF or low EF) ● Emergent coronary revascularization ● Previous coronary revascularization CONCLUSION ALEI after coronary revascularization is an infrequent but highly lethal event. Even in a hospital with extensive experience in treating CAD, complete preoperative vascular evaluation of patients at risk for ALEI appears to be infrequent. We believe that a more aggressive evaluation of patients at risk for ALEI before coronary revascularization will improve outcomes and simplify the management of ALEI if it develops. From these data analysis, a list of factors was compiled to designate patients who may be at risk for developing ALEI after coronary revascularization (Table 7). The implication for cardiovascular nursing practice is to use these risk factors in the prediction, prevention, and early recognition of ALEI in patients who undergo coronary revascularization. A baseline history and physical examination that are vascular-focused will reveal those patients who may be more at risk for ALEI and will assist in managing those who do develop ALEI. Future research must be done to determine whether consideration of these risk factors may prevent this lethal and morbid complication of coronary revascularization.

REFERENCES 1. Birkmeyer JD, O’Connor GT, Quinton HB, et al. The effect of peripheral vascular disease on in-hospital mortality rates with coronary artery bypass surgery. J Vasc Surg 1995;21: 445-52. 2. Davis C, VanRiper S, Longstreet J, et al. Vascular complications of coronary interventions. Heart Lung 1997;26(2): 118-27.

Physical examination ● Inadequate preprocedural physical examination ● Abnormal pulse examination ● Presence of arterial bruit or thrill ● Abnormal ankle-brachial index ⬍0.8 ● Indwelling interventional or diagnostic catheters ● Hemodynamic instability 3. Mesh CL, Cmolik BL, Van Heekeren DW, et al. Coronary bypass in vascular patients: a relatively high-risk procedure. Ann Vasc Surg 1997;11:612-9. 4. Ricci MA, Trevisani GT, Pilcher DB. Vascular complications of cardiac catheterization. Am J Surg 1994;167(4): 375-8. 5. Rihal CS, Sutton-Tyrell K, Guo P, et al. Increased incidence of periprocedural complications among patients with peripheral vascular disease undergoing myocardial revascularization in the bypass angioplasty revascularization investigation. Circulation 1999;100(2):171-7. 6. Hertzer NR, Beven EG, Young JR, et al. Coronary artery disease in peripheral vascular patients: a classification of 1000 coronary angiograms and results of surgical management. Ann Surg 1984;199(2):223-33. 7. American Heart Association. 2002 heart and stroke statistical update. Dallas: American Heart Association; 2001. 8. Fahey VA. Vascular nursing. 3rd ed. Philadelphia: WB Saunders; 1999. 9. Rutherford RB. Vascular surgery. 5th ed. Philadelphia: WB Saunders; 2000. 10. Comarow A. Higher volume, fewer deaths. US News and World Report July 2000;121(4):214-6. 11. Rihal CS, Eagle KA, Michel MC, et al. Surgical therapy for coronary artery disease among patients with combined coronary artery and peripheral vascular disease. Circulation 1995;91(1):46-53. 12. Sutton-Tyrrell K, Rihal C, Sellers MA, et al. Long-term prognostic value of clinically evident noncoronary vascular disease in patients undergoing coronary revascularization in

Vol. XX No. 3

JOURNAL OF VASCULAR NURSING www.mosby.com/vascnurs

the bypass angioplasty revascularization investigation (BARI). Am J Cardiol 1998;81(4):375-81. 13. Bensard DD, Krupski WC. Preoperative cardiac evaluation of patients for vascular surgery. Decision making in vascular surgery. St. Louis: WB Saunders; 1992. 14. Seidel HM, Ball JW, Dains JE, et al. Mosby’s guide to physical examination. 4th ed. St. Louis: Mosby; 1999. 15. Cook L, Pillar B, McCord G, Josephine R. Intra-aortic balloon pump complications: a five-year retrospective study of 283 patients. Heart Lung 1999;28(3):195-202. 16. Kantrowitz A, Wasfie T, et al. Intraaortic balloon pumping 1967 through 1982: analysis of complications. Am J Cardiol 1986;57:976-83. 17. Thomas TA, Taylor SM, Crane MM, et al. An analysis of limb-threatening lower extremity wound complications after 1090 consecutive coronary artery bypass procedures. Vasc Med 1999;4(2):83-8. 18. Cohen JR. Vascular surgery: for the house officer. 2nd ed. Baltimore: Williams & Wilkins; 1992. 19. Jackson MR, Clagett GP. Antithrombolytic therapy in peripheral arterial occlusive disease. Chest 2001;119(1):2835-995. 20. Shubrooks SJ, Malenka DJ, et al. Safety and efficacy of percutaneous coronary interventions performed immediately after diagnostic catheterization in northern New England and comparison with similar procedures performed later. Am J Cardiol 2000;86(1):41-5. 21. Eagle KA, Rihal CS, Foster ED, et al. Long-term survival in patients with coronary artery disease: importance of peripheral vascular disease. J Am Coll Cardiol 1994;23:1091-5. 22. Hannan EL, Kilburn H, O’Donnell JF, et al. Adult open-heart surgery in New York State: an analysis of risk factors and hospital mortality rates. JAMA 1990;264:2768-74.

PAGE 83

23. Parsonnet V, Bernstein DD. A method of uniform stratification of risk for evaluating the results of surgery in acquired adult heart disease. Circulation 1989;79(suppl I):I-3-I-12. 24. Paletta CE, Huang DB, Fiore AC, et al. Major leg wound complications after saphenous vein harvest for coronary revascularization. Ann Thorac Surg 2000;70(2):492-7. 25. Goldman L, Caldera DL, Nessbaum SR, et al. Multifactorial index of cardiac risk in noncardiac surgical procedures. N Engl J Med 1977;297:845-51. 26. Higgins TL, Estafanous FG, Loop FD, et al. Stratification of morbidity and mortality outcome by preoperative risk factors in coronary artery bypass patients: a clinical severity score. JAMA 1992;267:2344-8. 27. Mangano DT, Goldman L. Preoperative assessment of patients with known or suspected coronary disease. N Engl J Med 1995;333(26):1750-6. 28. Criqui MH, Fronek A, Melville R, et al. The sensitivity, specificity, and predictive value of traditional clinical evaluation of peripheral arterial disease: results from noninvasive testing in a defined population. Circulation 1985;71(3): 516-22. 29. Stoffers HE, Kester AD, Kaiser V, et al. The diagnostic value of the measurement of ankle-brachial systolic pressure index in primary health care. J Clin Epidemiol 1996;49(12):1401-5. 30. Moreno-Cabral CE, Mitchell RS, Miller DC. Manual of postoperative management in adult cardiac surgery. Baltimore: Williams & Wilkins; 1988. 31. Goldsborough MA, Miller MH, Gibson J, et al. Prevalence of leg wound complications after coronary artery bypass grafting: determination of risk factors. Am J Crit Care 1999;8: 149-53.

PAGE 84

JOURNAL OF VASCULAR NURSING www.mosby.com/vascnurs

SEPTEMBER 2002

Risk factors associated with lower extremity ischemia Contact Hours: 1.0 Test ID: JVN0292

Minimum Passing Score: 70% Test Processing Fee: $10.00

OBJECTIVES:

1. Describe risk factors associated with acute lower extremity ischemia (ALEI). 2. Identify study findings related to ALEI. 3. Discuss assessment parameters to determine high risk patients for ALEI. 1. The increased morbidity for patients following PTCA and CABSs was attributed to all of the following EXCEPT: a. Age b. Smoking c. Psychological adjustment to surgery d. Chronic renal insufficiency 2. Similar patients with vascular disease exhibited all of the following risk factors EXCEPT: a. Pulmonary embolism b. Congestive heart failure c. Diabetes mellitus d. Hypertension 3. What difference in complication rates was found between diagnostic and interventional catherizations? a. Diagnostic was 1%, interventional 7% b. Diagnostic was 3%, interventional 1% c. Diagnostic was 1%, interventional 3% d. Diagnostic was 7%, interventional 1% 4. Which of the following individuals would be considered at a higher risk for arterial injury? a. Males over 60 years b. Males under 60 years c. Females over 60 years d. Females under 60 years 5. Which group was the strongest predictor of adverse cardiac events for vascular patients? a. Unstable angina b. Pulmonary embolism c. Renal disease d. Congestive heart failure

6. What percentage of patients with ALEI after coronary revascularization were hemodynamicaly unstable? a. 10% b. 20% c. 60% d. 75% 7. The IABP has an associated complication rate of: a. 12%– 47% b. 30%– 60% c. 3%–10% d. 50%–75% 8. What ABI is indicative of AOD? a. .95–9.7 b. less than .8 c. .85–.90 d. .90 –.95 9. From the study, which risk factor was most prevalent? a. Hypertension b. Diabetes c. Smoking d. Hyperlipidemia 10. The most common finding of patients with ALEI was: a. Congestive heart failure b. Acute myocardial infarction c. Prior coronary revascularization d. Prior history of arterial occlusive disease 11. What was the least common vascular history reported by patients who developed ALEI? a. Active claudication b. Lower extremity amputation c. Lower extremity bypass d. Lower extremity paralysis

Vol. XX No. 3

JOURNAL OF VASCULAR NURSING www.mosby.com/vascnurs

PAGE 85

Nursing Continuing Education Answer/Enrollment Form JOURNAL OF VASCULAR NURSING Title: Risk factors associated with lower extremity ischemia

Test ID#: JVN0292 Minimum Passing Score: 70%

Contact Hours: 1.0 To receive CE credits, 1. Read the article, then answer the questions (There is only one right answer for each question). 2. Include the test processing fee of $10 with this answer form.

Make checks payable to BUCHANAN & ASSOCIATES (You may duplicate this answer form.)

3. Mail to: Buchanan & Associates, 1666 Garnet Ave #102, San Diego, CA 92109 You should receive your certificate within 3 weeks of mailing. Call 800.929.1233 or www.nursingce.com Name: (please print) First

RN License#: M.I.

Last

Mailing Address:

City:

Phone:

State:

Zip:

Soc Sec#:

ANSWERS: 1

6

11

16

2

7

12

17

3

8

13

18

4

9

14

19

5

10

15

20

How long did it take you to complete this program? Check the appropriate box Please evaluate the program using the following criteria. The course was able to meet the objectives and they were related to the overall purpose and goals of this program The objectives were related to the goals of this program

1/2-1 hour

1-1 1/2 hours

1 1/2-2 hrs

2 hrs or more

Strongly Agree

Agree

Neutral

Disagree

Strongly Disagree* (comments)

Objective #1 Objective #2 Objective #3 Objective #4 The information presented was accurate, current and at an appropriate educational level for this audience The teaching method was appropriate and effective for the material presented This program met my personal professional educational needs as it relates to this topic The information presented was relevant to my practice The teaching methodology (didactic) was appropriate to the material presented This form of continuing education was appropriate to the subject matter You may also submit the evaluation form to your local board of nursing in addition to Buchanan & Associates Comments and suggestions for future topics:

Buchanan & Associates is accredited as a provider of continuing education in nursing by the: American Nurses Credentialing Center, Commission on Accreditation, California Board of Registered Nursing CEP# 9473, Florida Board of Nursing FBN 2159.