Arteriovenous Malformations of the Brain

JULY 1987. VOI.. 46, NO I

A OR N J O U R N A L

Arteriovenous Malformations of the Brain Ruth E. Vaiden, RN; William R. White, MD

A

n arteriovenous malformation (AVM) is a tangled array of dilated vessels that form an abnormal communication between the arterial and venous systems. Arterial blood is shunted directly into the venous system without the usual connecting capillary network.' An arteriovenous malformation of the brain presents one of the most interestingand challenging problems in neurosurgery. Once an area of controversy, surgical treatment for AVM is now accepted. Because of modern techniques, AVMs arc being treated surgically in most hospitals with satisfactory results.

Pathophysiologv/Symptoms

A

rteriovenous malformations result from a failure in the development of capillary .networks between arteries and veins in the embryonic brain. Direct connections between the arterial and venous circulation result in a gradually enlarging nidus (nestlike structure) of thin-walled vessels engorged with arterial blood

under high pressure. As the fistulous connection(s) gradually enlarge, blood is diverted from the surrounding brain tissue, resulting in hypoxia of the adjacent brain-a phenomenon termed steal syndrome. The high pressure on the venous side of the circulation also adds to the poor tissue perfusion. Gliosis (gradual scarring) of the brain tissue immediately surrounding the AVM results from poor perfusion, which is caused by compression of the brain tissue by the AVM. This process is accelerated by multiple small hemorrhages caused by high intravascular pressure exerted on the thin walls of the vessels. Progressive neurological deficits consistent with the location of the AVM and the gliotic brain tissue may ensue. Seizure disorders are common. The most life-threatening complication is hemorrhage. Large intraparenchymal hemorrhages may result in stupor, coma, paralysis, and death. lntraventricular and subarachnoid hemorrhages are also common, and symptoms range from complaints of headache and stiff neck to stupor and coma.

Ruth E. Vaiden, RN, CNOR, is the director of neurosurgical nursing for Neurosurgical Associates. PC, Richmond, 'V She received her nursing diploma from Johnsron Willis Hospital School of Nursing, Richmond, Va

Ruth E. Vaiden

William R. White

William R. White, MD,is a neurosurgeon for Neurosurgical Associates, PC, Richmond, 'V He received his medical degree from Cornell University Medical College, New York City. 37

AORN JOURNAL

Hydrocephalus, a late complication. results from an obstruction in cerebrospinal fluid absorption because of repeated subarachnoid hemorrhages or an obstruction of the ventricular system by the AVM.

Indicationsfor Surgery

S

urgical treatment is indicated for progressive neurologic deficits or for a history of subarachnoid. intraventricular, or intraparenchymal hemorrhage. However, not every patient with these symptoms should be treated surgically, and some asymptomatic patients, in whom AVMs are found incidentally, benefit from surgery. A seizure disorder by itself is not an indication for surgery. A variety of factors must be considered. Age of the patient. There is a 3% incidence of recurrent hemorrhage per year in patients who have bled once.* No greater yearly risk exists for a young patient, but because of the longer life span, young patients who have hemorrhaged once are at significant risk to have another hemorrhage resulting in disability or death. More aggressive treatment is indicated in that situation than for an elderly patient with an asymptomatic AVM. Anatomic location. Arteriovenous malformations in eloquent areas of the brain (eg, motor, sensory, speech, or brainstem) have a high risk of postoperative neurologic deficits. In some AVMs in the brainstem and basal ganglia, risks for surgical treatment are prohibitive.3 To adequately expose an AVM in the brainstem may require sacrifice of normal tissue, which would result in significant neurological deficit. The risk of spontaneous hemorrhage seems to vary somewhat with location. Larger, diffuse, superficial AVMs may have less propensity to bleed than smaller, deep AVMs. Technical factors. Large, diffuse malformations with multiple feeder vessels from multiple parent arteries (eg, middle cerebral, anterior cerebral, and posterior cerebral) and malformations with high-flow shunts are more difficult to excise. They are also more prone to postoperative hemorrhage and cerebral edema than smaller lesions with only one or two feeding arteries. Adequate operative exposure of deep central 38

JULY 1987. VOL. 46, NO I

malformations is difficult to obtain, and therefore, poor results are more likely. After a hemorrhage, surgery is usually delayed from one to six weeks unless the hemorrhage is life threatening. Early rebleeding does occur but is not as common as in patients with berry (saccular) ane~rysms.~ To make an inoperable AVM surgically manageable, the patient may undergo preoperative embolization to reduce the size of the shunt and the number of arterial feeders. For the embolization procedure, small Mastic@ beads are introduced into the fistulous artery of the malformation via a catheter placed into the internal carotid. The beads enter the malformation and form a thrombus, which effectively blocks the vessels. Arteriograms are taken throughout the procedure to verify the position of the beads. This procedure is usually done one month before surgery. Proton-beam irradiation offers a nonsurgical alternative for some high-risk lesions. The radiation is used as an ablative procedure to shrink the AVM; stereotactic technique is used to direct the beam to the target area. With advancing technical capabilities, a large proportion of patients with symptomatic malformations can be treated surgically. Reduced operative morbidity and mortality has tilted the balance in favor of an aggressive surgical approach for many AVMS.~

Preoperative Care

P

reoperative testing includes computed tomography (CT) scanning to determine the size and location of the AVM and associated hemorrhages (Fig I ) . A four-vessel (right and left internal carotid arteries and vertebral arteries) angiogram is also done to locate the feeding arteries and venous drainage (Fig 2). The advantages of using magnetic resonance imaging for AVMs is unclear at the present time. Additional testing includes complete blood count, urinalysis, type and cross-match for four units of packed cells. electrocardiogram (ECG), and chest x-ray. The surgeon explains the surgical procedure and its associated risks and possible complications to

JULY 1987. VOL. 46. NO I

AORN J O U R N A L

Fig 1. Preoperative computed iomography scan showing hemorrhage.

Fig 2. Preoperative arteriogram showing the arteriovenous malformation in the brain.

the patient and family. These include possible lifestyle changes including alterations in personality, inability to resume previous employment, paralysis, and impaired speech. The degree of postoperative neurological deficits will depend on the size and location of the AVM and the amount of hemorrhage that has occurred. After the decision for surgery has been made, the patient signs the consent form, and the perioperative nurse assesses the patient and develops a care plan. The perioperative nurse reinforces what the surgeon has told the patient and family and encourages them to discuss any fears or concerns. The nurse tells the patient about being transferred to the holding area an hour before surgery, and that while in the holding area an intravenous (IV) line will be inserted. The nurse explains that the patient’s head may be shaved in the holding area or after anesthesia induction. The nurse also describes the postoperative dressing to the patient. The family is told that one of them can accompany the patient to the holding area and where they can wait while the patient is in the OR. They are also told that the procedure will

take approximately four to eight hours, and that the postanesthesia care unit (PACU) stay will be approximately one to three hours. From the PACU, the patient will be transferred to the intensive care unit (ICU) where he will stay for approximately two to three days. The nurse explains to the patient that an arterial line and central venous pressure line will be inserted in the OR after he is anesthetized, and that the arterial line will be used postoperatively in the PACU and ICU to draw any blood for necessary laboratory tests. The nurse also tells the patient that a Foley catheter will also be inserted after he is asleep, and that it along with the central venous pressure line will be used to determine fluid balance. The nurse documents the degree of preoperative neurological deficits such as paresis and paresthesia. The degree of paresis and paresthesia depends on the location of the AVM. The neurological deficits may be worse immediately postoperatively because of brain edema but usually improve after the brain edema decreases. The nurse also determines which measures to take to protect the patient’s skin and peripheral nerves during the procedure. 39

JULY 1987. VOL. 46, NO 1

AORN J O U R N A L

Table I

Equipment for Surgical Excision of AVM of the Brain Mayfield-pin headrest and a small, sterilely draped table with sterile points, plain sponges, povidone-iodine solution, and gloves for the surgeon Fiberoptic headlight Preferred suture Self-retaining brain retractor Foley cathether tray Anti-embolism stockings or two 4-inch and two 6-inch elastic bandages Operating microscope, 300 mm lens with video equipment, if available An assortment of temporary and permanent aneurysm clips with appliers Medium vascular ligating clips Unipolar and bipolar electrosurgical units Cottonoid patties and sheets Warming blanket (on the bed and one to cover the patient after positioning) Craniotome Collagen sponge Thrombin Absorbable gelatin sponge Microfibrillar collagen hemostat (Avitenes) Oxydized cellulose (Oxycels) Steroids (dexamethasone) Anticonvulsants (phenytoin sodium) Prophylactic antiobiotics of surgeon’s choice Sterile designed packs and trays for craniotomies help with the standard supplies and drapes for craniotomies

Surgical Preparation

T

he day of surgery, the circulating and scrub nurses open the craniotomy instruments, gather the necessary supplies and equipment, and count cottonoids, sponges, cotton balls, needles and knife blades (Table I). The circulating nurse ensures that the preoperative x-rays, including CT scans and angiograms, are available in the operating room. The four units of packed cells are kept in the blood bank until needed. 40

The circulating nurse goes to the holding area, identifies the patient, verifies the procedure, and checks the chart for completeness before transferring the patient to the OR. The patient is placed in the supine position on the OR bed, and the circulating nurse remains at the patient’s side to reassure the patient and assist the anesthesiologist. After anesthesia induction, the anesthesiologist inserts an arterial line, central venous pressure line, and a second IV. Prophylactic antibiotics may be started at this time, according to the surgeon’s choice. For young patients and alert adults, the head is shaved with a clippers and razor after anesthesia induction (for less alert adults, the head shave is sometimes done in the holding area). The circulating nurse inserts a Foley catheter and connects it to gravity drainage. He or she then applies elastic bandages to the patient’s legs if the patient does not have on anti-embolism stockings. The surgeon positions the patient’s head in the Mayfield-pin headrest. The patient remains in the supine position with the head slightly elevated in the headrest for the procedure. The circulating nurse applies the electrosurgical dispersive electrode pad to the patient’s thigh and ensures that all potential pressure areas are padded, especially the peripheral nerves. The nurse then preps the skin with povidone-iodine soap and solution, and the surgeon marks the incision site with a marking pen. Two sterile Mayo stands are strategically placed over the patient. This provides a tent-like area, which allows the anesthesiologist better access to the patient. The surgeon and scrub nurse apply the sterile drapes starting with four towels around the marked skin incision, followed by a split sheet with tails toward the head, a small sheet applied around the head, and then a cranial incise sheet that includes a transparent self-adhesive plastic drape. Depending on the position of the head, the surgeon may anchor the drapes with a 2-0 silk on a curved cutting needle-the head position depends on the location of the AVM. The scrub nurse places two sterile Mayo trays on the covered Mayo stands and connects the two suctions and the unipolar and bipolar electrosurgical units. The scrub nurse passes as many cords as possible off

JULY 1987. VOL. 46, NO I

AORN JOURNAL

Fig 3. Intraoperative view of the arteriovenous malformation and feeding arteries. the foot of the bed to prevent any clutter behind the surgeon and the assistant. The microscope is always placed on the anesthesiologist’sside of the bed before it is draped. Magnified vision with the operating microscope has greatly improved operative results. It allows AVMs to be removed from functional areas that previously had a high degree of operative morbidity and mortality associated with them. A viewing arm on the operating microscope and the video equipment allow the scrub nurse to watch what the surgeon is doing so the he or she can anticipate the surgeon’s needs. The patient’s intake and output is monitored jointly by the anesthesiologist and circulating nurse. The use of warmed saline for irrigation is monitored by the scrub nurse and reported to the anesthesiologist and circulating nurse, so they can subtract the amount from the measured blood loss. To decrease brain volume and thus relax the brain before retraction, the anesthesiologist administers 20 mg to 40 mg of furosemide (Lasix@) and up to 100 mg or 1 g/kg of body weight of mannitol (Osmitrol@) intravenously. The anesthesiologist also hyperventilates the

patient, which decreases his arterial carbon dioxide levels and results in a further decrease in intracranial pressure. The circulating nurse documents all nursing actions and patient responses preoperatively and intraoperatively in the patient record.

Operative Technique

T

he operative technique is similar to most craniotomies. A large bone plate is usually made to ensure adequate exposure of the AVM and all feeding arteries (Fig 3). The surgeon identifies the gliotic plane which separates the nidus of vessels from the surrounding brain. Working within this plane, the surgeon gradually coagulates or clips the arterial feeding vessels as close to the AVM as possible, preserving the normal arteries that pass beyond the AVM to distant normal brain. It is important for the surgeon to preserve at least one large draining vein until the end of the procedure. Premature interruption of the venous drainage can result in engorgement of the malformation with its blood supply under high pressure; uncontrolled bleeding or cerebral edema

d41

A O R N JOURNAL

JULY 1987, VOL. 46, NO I

Fig 4. Intraoperative view of brain after resection of the arteriovenous malformation.

Fig 5. Arteriovenous malformation specimen.

may result. If the drainage is preserved, inadvertent injury to the nidus can usually be controlled with bipolar coagulation or compression of the AVM with a cottonoid or an absorbable gelatin sponge. Temporary vascular clips can also be used to control bleeding and assist the surgeon in determining the flow characteristics of the malformation. Induced hypotension can also be 44

used to control bleeding. If the patient has an associated saccular aneurysm, it is also clipped with aneurysm clips. After the malformation is removed (Figs 4 and 5), the surgeon irrigates the wound and observes for bleeding. When the wound is dry, the surgeon closes the dura with 4-0 black braided nylon, places a closed suction drain in the epidural space,

AORN JOURNAL

JULY 1987. VOL. 46, NO 1

Fig 6. Postoperative computed tomography scan (le?)and angiogram showing complete removal of the arteriovenous malformation.

and replaces the bone plate securing it with 28gauge monofilament wire. The surgeon then closes the galea with 2-0 polyglactin and the skin with staples. The scrub and circulating nurses do a first closing count as the dura is being closed and a final count after the bone flap is in place. After the surgery is completed, the nurse paints the skin with povidone-iodine solution and assists the surgeon in applying the head dressing, which consists of nonadherent dressing, 4 x 4 plain gauze sponges, and a conforming stretch gauze head wrap. Depending on the patient’s responsiveness to stimuli, he may be extubated in the OR, PACU, or ICU.

Postoperative Care

D

uring the one- to three-hour PACU stay, the head of the bed is elevated between 15 and 30 degrees to help decrease intracranial pressure. The PACU nurse reviews arterial blood gas results to assess the patient’s respiratory system, and measures the CVP and urine output to assess the patient’s fluid status. The nurse also does periodic neurological checks 46

for abnormal pupillary reflexes, diminished sensorium, and an increase in preoperative neurological deficits. Vital signs are assessed continually on ECG and arterial line monitors to check for a rising blood pressure, which could increase intracranial pressure and bleeding. When the patient is in ICU, his head remains elevated and the nurses continue to assess intake, output, and vital and neurological signs for abnormalities indicative of bleeding and increased intracranial pressure. The nurse on the postsurgical unit also keeps the head of the patient’s bed elevated between 15 and 30 degrees and checks the patient’s vital signs and neurological signs every four hours. During the next several days the Foley catheter, arterial line, and CVP line are removed after it is determined that the patient’s vital signs and fluid and electrolyte status are normal, and that his neurological condition is stable. The closed suction drain is removed on the first postoperative day. The dressing is also changed when the drain is removed and again on the second or third postoperative day. Intravenous fluids are discontinued, and the patient is allowed a regular diet

JULY 1987, VOL. 46, NO I

when he is alert and no longer nauseated. Gradual ambulation begins on the first postoperative day. The patient is usually discharged one week postoperatively, unless he needs rehabilitation for neurologic deficits. Successful outcome for any surgery is accomplished with the combined team effort of the surgeon, nurses, and the anesthesiologist. The confidence, competence, and commitment of the entire team leads to a successful outcome.

Case Study

T

he series of scans, angiograms, and operative pictures used in this article (Figs 1, 2, 3, 4, and 5 ) illustrate the typical patient. The patient is now in his early thirties. Four years ago he developed a sudden severe headache, nausea, and vomiting. A left homonymous field cut (loss of vision in half of the visual field of both eyes) was found on examination. He was brought to the emergency room within a few hours of onset. The CT scan showed a moderate-sized hemorrhage in the right posterior temporal region. An angiogram also showed a moderate-sized AVM and identified feeders mainly from the middle cerebral artery. He was stable neurologically and did not seem to be in immediate danger of herniation of the temporal lobe. Signs and symptoms of impending herniation include decreased level of consciousness, pupillary abnomalities, motor dysfunction, and alterations in vital signs. He was observed for 10 days and then underwent a right parietotemporal craniotomy and excision of the AVM. Postoperative CT scanning and angiography showed complete excision of the AVM (Fig 6). He recovered well and has now returned to his previous employment. He had one seizure when his anticonvulsants were discontinued a year after surgery. His main complaint now is that he cannot pilot an airplane because of his seizure disorder and mild residual field cut. 0 Notes I . J Hickey. The Clinical Pruclice of Neurological and Neurosurgical Nursing. second ed (Philadelphia: J B Lippincott Co. 1986) 532. 2. D Fults. L Kelly, “Natural history of arteriovenous

AORN JOURNAL

malformations of the brain: A clinical study,” Neurosurgrrv 15 (November 1984) 658-662. 3. R Spetzler, N Martin. “A proposed grading system for arteriovenous malformations.” Journul of Neurosurgerv 65 (October 1986)476-483. 4. L Malic, “Arterioveneous malformations of the brain,” in Neurological Surgery, ed. J Youmans, vol 3 (Philadelphia: W B Saunders Co, 1982) 1786-1805. 5. Ibid. Suggested reading Luessenhop. J; Gennarelli. A. “Anatomical grading of supratentorial arteriovenous malformations for determining opera bi I i t y .” Neurosurgerv I ( J u 1y / August 1977) 30-35. Sugita. K . Micro-Ncwrosurgical Aths. Heidelberg. Germany: Springer-Verlag. 1985.

Noninvasive Methods Can Assess Venous Function Noninvasive methods may be used to check the efticacy of varicose vein surgery, venous valve repair, or reconstructive venous procedures. According to a study published in the March 1987 issue of Surgery, surgeons can effectively check the venous muscle pump function by using ambulatory calf volume strain gauge plethysmography to determine the venous reflux and expelled volume. This enables surgeons to select patients and evaluate the success of the surgery without using invasive methods. According to the article, invasive methods are time-consuming, difficult to perform, and, in general, unsuitable for repeated measurements in a patient. In the study, researchers from the University of Copenhagen, Denmark, tested 21 patients who had surgery for varicose veins. They tested the patients before surgery, three months after surgery, and 60 months after surgery. Results taken by plethysmography showed that after 60 months, mean venous reflux recordings were reduced by 54% and the mean venous expelled volume increased by 58%. Both readings were statistically significant, according to the researchers. In conclusion, the researchers stated that the effect of varicose vein surgery can be assessed by noninvasive means. 47

JULY 1987, VOL. 46, NO I

AORN JOURNAL

Mesh Stent Being Used in Coronary Angioplasty European cardiologists received a positive response when they introduced a flexible stainless steel mesh stent to maintain vessel patency. The mesh stents have been successful in preventing repeat restenosis in patients with postangioplasty stenosis or clogged bypass vein grafts, according to an article in the April 13 issue of Medical World News. Cardiologists in the United States have been disappointed with the 30%restenosis rate in percutaneous transluminal coronary angioplasty. In a presentation at the American College of Cardiology, New Orleans, researchers said that studies conducted at the Center Hospital and Vaudois University, both in Lausanne, Switzerland, and at Rangueil Hospital, Toulouse, France, were positive. Twenty-five patients at Center Hospital and Vaudois University received the flexible stents; seven for acute postangioplasty occlusion, 19 for later restenosis, and three for bypass graft steno-

sis. Follow-up testing at five months and 12 months showed undiminished patency in all but two of the stent sites. Spasm and thrombosis were the primary p r o b lems associated with the stent implantation. Four instances of thrombosis-three of which were resolved with urokinase-and four instances of spasm occurred in the patients. Thrombosis usually formed within the first 10 days after implantation, and appeared to occur when the stent was too large for the artery. The instances of spasm were reported to occur distal to the stent, according to the article. Nineteen patients at Rangueil Hospital also received the mesh stents. Twelve implants were event-free, and the last six patients did not have any problems whatsoever.

FOOT ACTIVATED OR HAND CONTROLLED

BIPOLAR COAGULATING FORCEPS Compatible with the most popular coagulating units available Stainless steel or Titanium forceps Highly polished tips, Satin finish body Precision tip alignment Light closing force for less fatigue Effective in dry or wet field Insulated and non-insulated

Please send for new ASS1 Surgical Catalog.

accurate surgical & scientific instruments corporation 300 SHAMES DRIVE, WESTBURY, NY 11590, PHONE (516) 333-2570 TO ORDER CALL TOLL FREE

48

(Except N Y Stale

1-800-645-3569 call 516-333-2570

WEST COAST SALES: SAN DIEGO, CA (619) 235-9400

1-800-ALL-WEST

(CALIFORNIA, PACIFIC and MOUNTAIN TIME STATES)

JULY 1987, VOL. 46, NO 1

AORN JOURNAL

Examination HOMESTUDYPROGRAM

1. An arteriovenous malformation (AVM) is a tangled array of dilated vessels that form an abnormal communication between the arterial and venous systems a) true b) false 2. In AVM patients, gliosis of the brain tissue surrounding the AVM is caused by a) increased intracranial pressure b) obstructed cerebrospinal fluid absorption c) poor perfusion d) seizure disorders 3. The most serious complication of an AVM is a) a seizure disorder b) hemorrhage c) the steal syndrome d) paralysis 4. A late complication of AVMs is a) seizure disorders b) hydrocephalus c) gliotic brain tissue d) visual deficits 5. Surgical treatment of an AVM patient is indicated for a ) progressive gliosis b) a seizure disorder c) a history of intraparenchymal hemorrhage d) an AVM located in the brainstem 6. The risk for hemorrhage associated with AVMs a) varies with the anatomical location of the AVM b) is high with large, diffuse, superficial AVMs

c) is low with smaller, deep AVMs d) is low in a young patient who has hemorrhaged once 7. Excision of an AVM can be more difficult if it a) is a smaller malformation b) is a superficial central malformation c) has low-flow shunts d) has multiple feeder vessels 8. After a hemorrhage, surgery is usually delayed for a) one to six weeks b) eight to 12 weeks c) four to six months d) eight to 12 months 9. The embolization procedure is performed preoperatively to reduce the size of the shunt and the number of arterial feeders a) true b) false 10. Preoperatively, management of the AVM patient will include measures to prevent hemorrhage such as maintaining a quiet therapeutic environment to control any activity or stress that could elevate the systemic blood .pressure a) true b) false 1 1. Preoperative testing of a patient with an AVM includes a) magnetic resonance imaging b) proton-beam radiation c) four-vessel angiogram d) embolization 12. Preoperatively, the perioperative nurse 49

reinforces what the surgeon has told the patient and family about the associated risks and complications of AVM surgery, which include alterations in personality, paralysis, and impaired speech a) true b) false 13. Postoperative neurological deficits associated with an AVM depend on the a) age of the patient b) size and location of the AVM c) position of the patient’s head during the surgical procedure d) amount of preoperative seizure activity 14. To decrease the patient’s brain volume intraoperatively, the anesthesiologist a) administers vasodilating medications b) hypoventilates the patient c) administers osmotic diuretics d) places the patient in the Trendelenburg position 15. Before excising the malformation, the surgeon clips all of the draining veins to prevent uncontrolled bleeding a) true b) false 16. The nurse in the PACU assesses the patient’s vital signs to check for a rising blood pressure, which could increase intracranial pressure and bleeding a) true b) false 17. The PACU nurse ensures that the head of the patient’s bed is elevated between 15 and 30 degrees to a) prevent seizure activity b) prevent blood loss c) help decrease intracranial pressure d) facilitate respiration 18. In caring for the AVM patient, the nurse must be aware of the signs of increased intracranial pressure including respiratory irregularities, bradycardia, and pupillary dysfunction a) true b) false 19. On the first postoperative day, the AVM patient will a) no longer require assessment of so

neurological signs b) have no ambulation restrictions c) no longer need the head of the bed elevated d) have the closed suction drain removed and head dressing changed 20. Signs and symptoms of impending herniation of the brain include respiratory irregularities and hemiplegia a) true b) false Editor j . note: Professional nurses are invited to submit manuscriptsfor the home s t d y program Manuscripts or queries should be sent to the Editor, AORN Journal I0170 E Mississippi Ave, Denver, CO 80231. As with all manuscripts sent to the Journal papers submined for home s t d y program should not have been previously published or submined simul&neously to any other publication

National Center Promoting Autologous Donation A National Autologous Blood Resource Center is being established to promote autologous transfusion, which is the donation and storage of one’s own blood for upcoming elective surgery. The term also refers to the salvage and transfusion of one’s own blood lost during and after surgery. The center has developed professional and public education materials to increase the use of these procedures. Currently, autologous blood transfusion represents only 1%of all blood transfused in the United States, but the American Association of Blood Banks (AABB) predicts that it will increase to at least 5% in the next two years, according to a press release from the AABB. For more information about autologous donation or about the new resource center, write the National Autologous Blood Resource Center, 1 1 17 N 19th St, Suite 600, Arlington, VA 22209.

JULY 1987, VOL. 46. NO

AORN JOURNAL

Answer Sheet ARTERIOVENOUS MALFORMATIONS OF THE BRAIN

P

lease fill out the application and answer form below. Tear out the page from the Journal or make photocopies. The deadline for this program is Jan 3 I , 1988. 1. Record your identification number in the appropriate section below. 2. Completely darken the space that indicatesyour answer to the examination starting with question one. 3. A score of 70%correct is required for credit. 4. Enclose fee: Members $5; Nonmembers $12.

Mail to: AORN Accounting Department c/o Home Study Program 10170 E Mississippi Ave Denver, Colorado 8023 I Mark only one answer per question

Name Address City State

Zip

Session # 5446

Event # 885005

Program offered July 1987 AORN (ID) #

RN license and state Florida license # (Required lor I Ikiridd ( I Credit)

If nonmember, please provide Social Security #

Fee enclosed of bill the credit card indicated

0 Master Card Card #

0 Visa

~

Expiration Date

Please complete this evaluation of the home study program; I = low and 5 = high. To what extent: Did the program increase your knowledge of the subject matter? Were the objectives of this program met? Was the content clear and organized? Did this article facilitate your learning? Were your individual objectives met? 52

(Low) (1) (1) (1) (1) (1)

(2) (2) (2) (2) (2)

(3) (3) (3) (3) (3)

(4) (4) (4) (4) (4)

(High) (5) (5) (5) (5) (5)

1