Vascular System 223 B. Physiological control. 1. Autoregulation: the ability of tissue to control its own blood flow. Autoregulatory system enables blood supply to vital organs (brain, kidney, heart) to remain relatively constant, even though blood pressure may fluctuate within normal ranges. 2. Nervous system control. a. Parasympathetic nervous system: influence on blood flow is the regulation of the heart rate by the vagus nerve. b. Sympathetic nervous system. (1) Primary influence of sympathetic system is on arterioles for dilation and constriction of the vessels in order to maintain peripheral resistance and vasomotor tone. (2) Peripheral resistance is resistance of arterioles to flow of blood. (3) Dilation decreases peripheral resistance, thereby decreasing blood pressure; vasoconstriction increases peripheral resistance, thereby increasing blood pressure. Blood Pressure A. Systolic blood pressure is the arterial pressure at the peak of ventricular contraction. The systolic pressure is determined primarily by the amount of blood ejected. B. Diastolic pressure represents the pressure exerted in the arteries at the end of systole; it is the resting ventri- cular pressure. Diastolic pressure depends on the ability of the arteries to stretch and handle the blood flow. C. Pulse pressure is the difference between the systolic and diastolic pressures. DISORDERS OF THE VASCULAR SYSTEM Atherosclerosis Atherosclerosis is the most common disease of the arteries. The word means “hardening of the arteries.” A. Atherosclerosis: most common classification of arterio- sclerosis; characterized by stenosis and obstruction in the lumen of the vessel (Figure 11-1). 1. Process is slow; generally no evidence of problems until a major artery is affected and there is severe decrease in blood supply to tissue supplied by artery involved. ✽ PHYSIOLOGY OF THE VASCULAR SYSTEM Vessels A. Arteries. 1. Primary function is to transport nutrients and oxygen to the cellular level. 2. Arterial vascular system is a high-pressure system with a rapid blood flow. B. Capillaries. 1. Microscopic vessels at the cellular level. 2. Capillary bed is the area of circulation where the arterioles branch into capillaries and exchange between the circulating blood volume and the interstitial fluid occurs. C. Veins. 1. Primary function of the veins is to return blood to the heart. 2. Veins contain valves to maintain direction of blood flow and to prevent the backflow of blood. 3. Venous system is a low-pressure system. D. Circulatory systems. 1. Systemic circulation: the flow of blood from the left ventricle into the aorta and through the arteries to the capillary beds, where cellular nutrition and oxygenation occur; then blood returns to the right atrium of the heart via the veins. 2. Pulmonary circulation: the flow of blood from the right ventricle into the pulmonary artery and then into the lungs; in the capillary beds of the lungs, the blood picks up oxygen and releases carbon diox- ide and then returns to the left atrium through the pulmonary veins. 3. Hepatic-portal circulation: the flow of blood from the venous system of the stomach, intestines, spleen, and pancreas into the portal vein and through the liver for absorption of nutrients and removal of toxins. Venous blood leaves the liver through the hepatic vein and flows into the inferior vena cava for return to the right atrium. E. Lymphatic system: primary function is to return fluid and protein to the blood from the interstitial fluid. Mechanics of Blood Flow A. Blood flow is controlled by: 1. The diameter of the vessel. 2. The length of the vessel. 3. The pressure at either end of the vessel. 4. The viscosity of the blood.
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Vascular System
223
B. Physiologicalcontrol. 1. Autoregulation:theabilityoftissuetocontrolits ownbloodflow.Autoregulatorysystemenables bloodsupplytovitalorgans(brain,kidney,heart)to remainrelativelyconstant,eventhoughblood pressuremayfluctuatewithinnormalranges. 2. Nervoussystemcontrol. a. Parasympatheticnervoussystem:influenceon bloodflowistheregulationoftheheartrateby thevagusnerve. b. Sympatheticnervoussystem. (1)Primaryinfluenceofsympatheticsystem isonarteriolesfordilationandconstriction ofthevesselsinordertomaintainperipheral resistanceandvasomotortone. (2) Peripheralresistanceisresistanceof arteriolestoflowofblood. (3) Dilationdecreasesperipheralresistance, therebydecreasingbloodpressure; vasoconstrictionincreasesperipheral resistance,therebyincreasingbloodpressure.
Atherosclerosis is the most common disease of the arteries. The word means “hardening of the arteries.”A. Atherosclerosis:mostcommonclassificationofarterio- sclerosis;characterizedbystenosisandobstructionin thelumenofthevessel(Figure11-1). 1. Processisslow;generallynoevidenceofproblems untilamajorarteryisaffectedandthereissevere decreaseinbloodsupplytotissuesuppliedbyartery involved.
2. Arteriescommonlyaffectedbyatherosclerosis: a. Coronaryarteries. b. Cerebrovasculararteries. c. Aorta:mayleadtoaorticaneurysm. d. Peripheralarteries.
Hypertension is a consistent increase in blood pressure.A. Classification. 1. Essential(primary,benign,idiopathic):etiologyun- known;accountsforapproximately85%to95%of hypertensiveclients. 2. Secondary:accountsforapproximately10%to15% ofhypertensioncases;thesustainedelevationisdue toanidentifiablecause. a. Increasedintracranialpressure. b. Renaldisease. c. Pregnancy-inducedhypertension(toxemia). d. Cushing’ssyndrome. e. Thyrotoxicosis. 3. Malignanthypertension:asustainedincreaseinthe diastolicpressurethatisunresponsivetotreatment. 4. Hypertensivecrisis:whenthedegreeofhyperten- sionisalife-threateningsituation.
Data CollectionA. Riskfactorsinessentialhypertension(Table11-1).B. Clinicalmanifestationsofessentialhypertension.
NURSING PRIORITY – Encourage blood pressure monitoring in clients with increased risk, hypertension is most often asymptomatic.
FIGURE 11-1 Pathophysiology of Atherosclerosis From Ignatavicius, DD, Workman, ML: Medical Surgical Nursing Patient-Centered Collaborative Care, ed 6, St Louis, 2010, Saunders.
CHAPTER 11 Vascular System 225
TABLE 11-1 RISK FACTORS IN ESSENTIAL HYPERTENSION
Nonmodifi able Factors Modifi able FactorsAge:B/Pprogressivelyincreaseswithage,commonlyincreases Obesity:centralabdominalobesity.betweenages30-50years. Stress:repeated,prolongedstress.prevalentinwoman.Gender:moreprevalentinmenuntilage55,andthenmore Excesssodiumintake:causesfluidretentionandcontributestoEthnicgroup:higherinAfricanAmericansthaninwhites. increasedbloodpressure.Familyhistory:especiallyifcloserelativehashypertension. Elevatedlipidlevels:hyperlipidemiaiscommoninclientswith highB/P. Substanceabuse:excessivealcoholintake,tobaccouse. Sedentarylifestyle:regularphysicalactivityhelpstodecreaserisk.
TEST ALERT: Review with client understanding of health promotion behaviors.
OLDER ADULT PRIORITY: Older adults are more sensitive to blood pressure changes. A drop in blood pressure to less than 120 mm Hg systolic may cause orthostatic hypotension.
C. Maintainlow-sodiumdiet.D. Assesschangesinweightwithregardtolow-sodium intakeanduseofdiuretics.E. Whenbloodpressure(BP)isinitiallydecreased,evalu- ateclient’stolerancetodropinBP.
Also known as peripheral vascular disease (PVD), this disorder primarily involves narrowing and obstruction of the of the extremities, especially the lower extremities. The atherosclerotic lesions cause chronic arterial obstruction that progressively leads to decreased oxygen delivery to the tissues.A. Lesionsarepredominantlyfoundintheloweraorta, frombelowtherenalarteriesextendingthroughthe poplitealarea.B. Bythetimesymptomsoccur,thearteryisapproximate- ly85%to95%occluded.C. Therenal,femoral,popliteal,andaorticiliacarteries arethemostcommonlyaffectedsites.
Data CollectionA. Riskfactors(sameasforhypertension–Table11-1).B. Clinicalmanifestations.
TEST ALERT: Recognize the client with conditions resulting in inadequate circulation of
lower extremities.
1. Intermittentclaudication(painwithactivity,re- lievedbyrest). 2. Ischemicpainatrest,orpainatnightindicatesad- vancedstagesofPVD. 3. Paresthesiaofthefeet. 4. Decreasedorabsentperipheralpulses(Figure11-2). a. Dorsalaspedis,posteriortibial. b. Popliteal. c. Femoral. 5. ArterialUlcers. a. Commonlyfoundonmetatarsalheadsandtips oftoes. b. Painful,sharpedges,palecolorbase,frequently occursonthelargetoe. c. Poorhealingofinjuriesontheextremitiesdueto lackofcirculation. 6. Changesintheskin. a. Cooltotouch.
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1. Presenceofposturalhypotension. 2. Changeinurinaryoutput. 3. Changeinenergylevel. 4. Changesinlevelofconsciousness.F. Report signifi cant changes in BP to the charge nurse.
NURSING PRIORITY: Obtain hemodynamic mea-surements: the BP of a hypertensive person should be measured lying down, sitting and standing; measure the BP in both arms.
BOX 11-2 LIFESTYLE MODIFICATIONS FOR HYPERTENSION PREVENTION AND CONTROL
TEST ALERT: Review client/family understanding of health promotion behaviors.
CHAPTER 11 Vascular System 227
b. Shiny,fragile,poorturgor. c. Dry,scaly. d. Lossofhaironthelowerleg. 7. Brittle,thicktoenails. 8. Dependentrubor(duskyredness)whenlegsarein- dependentposition,pallorwithelevationofthelegs.C. Diagnostics- seeAppendix11-1.
Treatment A. Medical. 1. Vasodilatingmedications. 2. Decreaseprogressionofatherosclerosis. a. Decreasedietarycholesterolintake. b. Initiateanexerciseprogramastolerated. c. Stopalltobaccouse. d. Decreaseweightifappropriate. 3. Preventandcontrolinfections. 4.Treatmentofdiabetes.B. Surgical:Proceduresareperformedwhenintermittent claudicationinterfereswiththeclient’sactivitiesof dailylivingorwhenthecirculationmustberestored inordertosalvagethelimb. 1. Peripheralatherectomy:removalofplaquewithin theartery. 2. Bypassgraft:bypassofanobstructionbysuturinga graftproximallyanddistallytotheobstruction. 3. Patchgraftangioplasty:arteryisopened,plaqueis removed,andapatchissuturedintheopening towidenthelumen. 4. Amputation:usedasalastresortwhenother therapieshavefailedandgangreneorinfectionis extensive.C.Nonsurgical. 1. Percutaneoustransluminalangioplasty:useofa ballooncathetertocompresstheplaqueagainstthe arterialwall. 2. Laser-assistedangioplasty:aprobeisadvanced throughacannulatotheareaofocclusion;alaseris usedtovaporizetheatheroscleroticplaque. 3. Intravascularstent:placementofastentwithina narrowedvesseltomaintainpatency.
TEST ALERT: Review assessment of peripheral pulses, report signs of potential complications.
v Goal: Topreventinjuryandinfection.A. Avoidvigorousrubbingoftheextremity.B. Preventpressuretoheels,ankles,toes.C. Useheelcoversandbedcradletopreventpressureon thetoesandheels.D. Maintaingoodskinhygieneandpropercareoftoenails. 1. Donottrimthetoenails. 2. Donottrimcallusesorcorns. 3. Advise RN or HCP if client has ingrown toenails. 4. Keepfeetcleananddry,donotsoakfeet,use lubricatinglotiontopreventskincracks. 5. Teachclienttoalwayswearshoes;avoidshoesor socksthataretootight.
TEST ALERT: Identify methods for preventing complications associated with illness. Identify
factors that affect wound healing.
Figure 11-2 Pulse Points for assessment of arterial pulse, From: Ignatavicius, DD, Workman, ML: Medical Surgical Nursing Patient-Centered Collaborative Care, ed 6, St Louis, 2010, Saunders. Page 717, Fig 35-6.
NURSING PRIORITY: In planning and caring for the diabetic client, problems of peripheral vascular disease must be considered. Poor peripheral circulation is a common complication.
NURSING PRIORITY: The vascular problem has a direct relationship to cigarette smoking. The client should understand that in order for the condition to be controlled, he must quit smoking.
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✔
Raynaud’s Disease
A disease characterized by episodic spasms of the small cutaneous arteries. It occurs primarily in the fingers.
Raynaud’s Phenomena
A. Intermittentepisodicspasmsofthearteriolesofthe fingers,toes,nose,andears.Spasmsarenotnecessarily correlatedwithotherperipheralvascularproblems.B. Conditionusuallyoccursinthehandsandisbilateral andsymmetrical.
TEST ALERT: Recognize client conditions that result in insufficient vascular perfusion; review
assessment of peripheral pulses of client. Pulse checks are critical in vascular surgery client. The nurse should compare the peripheral pulses in the lower extremities and initiate protective and preventative actions.
E. Nasogastricsuctionisfrequentlyusedintheimmediate postoperativeperiodtopreventgastricdistentionfrom causingincreasedpressurearoundareaofthegraft.
Home CareA. Activityrestrictions. 1. Noheavyliftingfor6-12weeks. 2. Avoidactivitiesthatinvolvepushing,pulling,or straining.B. Reportanysignsofinfection,redness,swelling,drain- age,orfever.
Shock (Severe Hypotension)
Shock is characterized by inadequate blood flow and tissue perfusion.A. Foradequatecirculationtooccur,allpartsofthecircu- latorysystemmustfunctioneffectivelytogether. 1. Adequatevasculartonetomaintainnormal resistanceofthevessels. 2. Abilityofthehearttomaintaincardiacoutput. 3. Adequateamountoftotalbloodvolume.B. Theinitialproblemsprecipitatingshockandthespe- cifictreatmentfortheproblemsareverydifferent. However,regardlessoftheprecipitatingcauseofshock, theunderlyingproblemisinadequatetissueperfusion.C. Classificationsofshock. 1. Hypovolemicshock:sizeofvascularcompartment remainsthesamewhilethevolumeofbloodor plasmadecreases;mayberelativeorabsolute. a. Hemorrhage. b. Burns. c. Severefluidloss. 2. Cardiogenicshock:heartisunabletoeffectively circulatetheintravascularvolume. a. Dysrhythmias. b. Myocardialinfarction(MI). c. Heartfailure. 3. Distributiveshock:anincreaseinthebloodvolume onthevenoussidewithadecreaseinthevenous returntotheheart. a. Neurogenic:spinalcordshock;lossofnerve supplytobloodvessels. b. Septic:vasodilationfromsevereinfection. c. Anaphylactic:vasodilationsecondaryto histaminerelease(allergicreactions). 4. Obstructiveshock:physicalimpedimenttoblood flow. a. Pulmonaryembolism. b. Venacavacompression. c. Tensionpneumothorax.
Data CollectionSignsandsymptomsofshockareessentiallythesameregardlessoftheprecipitatingcause.
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TEST ALERT: Implement interventions to man-age potential client circulatory complications. Be
able to recognize clients at increased risk; know the early symptoms of shock and initiate protective and preventive actions.
TEST ALERT: Identify client factors that could interfere with elimination. Decreased urinary
output is often an early observable sign of decreased renal perfusion secondary to decrease in cardiac output.
A. Evaluateurineoutputhourly.B. CarefullyassessrenalresponsetoincreaseinIVfluids.C. MonitorBUNandcreatinineforevidenceofrenalcom- plications.v Goal:Tomaintainhomeostasisanddecreaseeffectsofshock.A. Monitorclientresponsetomedicationstocounteract effectsofshock(seeAppendix11-6).B. Continuetoorientclient.C. Decreaseunnecessarysensorystimuli.D. MaintainNPO;provideoralhygiene.E. Evaluateforbowelsoundsanddistentiondueto intestinalischemia.F. Keepclientcomfortablywarm;donotallowchilling.F. DonotadministermedicationsPO,IM,or subcutaneouslybecauseofdecreasedtissueperfusion. (RN or HCP will administer medications IV push.)
G. Provideemotionalsupport;continuetotalkwithclient anddescribeproceduresbeforetheyaredone.H. Avoidunnecessarynursingprocedures.
Chronic Venous Insufficiency and Venous Stasis Ulcers
Chronic venous insufficiency (CVI) results from damage to the valves of the veins in the legs. A. Theprimarycauseofchronicvenousinsufficiencyis incompetentvalvesofthedeepveins,primarilyin thelowerextremities.B. Compressionandreliefofvenouscongestionarethe keyfactorstotreatmentandpreventionofCVI.C. Thisvalvularincompetenceleadstoregurgitationof blood,venouspooling,andedemainthelower extremities;eventuallyresultingindevelopmentof venousstasisulcers.
TEST ALERT: Implement measures to promote venous return, to manage potential circulatory
complications, and to monitor wounds for signs and symptoms of infection.
Varicose Veins
Varicose veins occur when veins in the lower trunk and extremities become congested and dilated because of incompetent valves in the vessels, as well as loss of elasticity of the vessel wall. As venous pressure increases, the-muscle around the vein fails to constrict effectively, and there is increased congestion and decreased venous return.
Problem begins with an inflammation of the vein. The inflammatory process may initiate a clot formation and the development of deep vein thrombosis (DVT). Thrombi occurring in the deep veins of the pelvis, legs, and abdomen are of particular concern because there is increased incidence of embolus formation.
TEST ALERT: Identify complications of im-mobility. Monitor client responses to interventions
for preventing complications from immobility. With any condition that causes an increase in venous stasis or inflammation to a vein, there is a significant increased risk for the development of thrombophlebitis and DVT.
Data CollectionA. Riskfactors(Virchow’sTriad). 1. Venousstasis. a.Surgery(hip,pelvicandorthopedicsurgeryare associatedwithhighrisk). b.Pregnancy,obesity. c. Prolongedimmobility(bedrest,longtrips, prolongedsitting). d.Heartdisease(atrialfibrillation,congestiveheart failure). 2. Hypercoagulability. a. Malignancies,dehydration. b.Blooddyscrasias. c.Oralcontraceptives,hormonereplacement therapy. d.Pregnancyandpostpartum. 3. Endothelialdamage. a. IVfluidsanddrugs(IVcatheterization,drug abuse,causticsolutionsordrugs) b.Abdominalandpelvicsurgery.
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c. Fracturesanddislocations(especiallyofthepelvis, hip,orleg). d. HistoryofDVT.B. Clinicalmanifestations. 1. Redness,warmth,andtendernessalongvein. 2. Crampingcalfpain. 3. Swollenextremity. 4. Warm,cyanoticskin. 5. Increasedtemperature. 6. Homans’sign:thisisnolongerconsideredan accurateindicatorofthrombophlebitis.
NURSING PRIORITY: Do not attempt to check Homans’ sign on a client with a diagnosis of thrombo-phlebitis. This can cause embolization of a thrombus that is present.
C. Diagnostics(Appendix11-1).D. Complications. 1. DVTassociatedwithhighriskforpulmonary emboli. 2. Chronicvenousinsufficiencyandvenousstasis ulcers.
TEST ALERT: Implement measures to manage potential circulatory complications. Due to the
multiple types of conditions that precipitate circulatory complications, questions may be incorporated into the care of the surgical client, the obstetric client, or any client with problems of circulation or immobility.
NURSING PRIORITY: The best way to prevent the development of a pulmonary emboli is to prevent the development of DVT or thrombophlebitis. It is much easier to prevent the problem than it is to treat it.
Appendix 11-2 ANTIHYPERLIPIDEMIC MEDICATIONSMedications Side Effects Nursing ImplicationsAntihyperlipidemics:DecreaseLDLcholesterol,butpreferablydonotdecreasetheHDLcholesterol.Usedincombinationwithdietaryrestrictions,exercise,andsmokingcessationtoreducebloodlipidlevels.
General Nursing Implications—Adviseclientthatserumliverenzymesshouldbemonitoredthroughouttherapy.—Medicationsshouldbetakenwiththeeveningmealoratbedtime.—Medicationsshouldbeusedinconjunctionwithotherlipid-loweringtherapies(exercise,low-cholesteroldiet,smokingcessation).—Serumcholesterolandtriglyceridelevelsshouldbemonitoredperiodicallythroughouttherapy.Medications Side Effects Nursing ImplicationsCholestyramine(Questran):POColestipol(Colestid):PO
TEST ALERT: Observe for effects of medications. Review the nursing implications associated with administration of anticoagulants.
HIGH
ALERT
240 CHAPTER 11 Vascular System
Appendix 11-4 ANTIHYPERTENSIVE MEDICATIONSMedications Side Effects Nursing Implications
General Nursing Implications—Adviseclientthatpostural(orthostatic)hypotensionmayoccurandhowtodecreaseeffects.Sitonsideofbedbeforestanding,makesureclientisstablebeforestanding.Donotstandforprolongedperiodsoftime.OlderclientisatincreasedriskMayoccurwithfirstdoseorsubsequentdoses.Problemismostoftentemporary.—Hypotensionmaybeincreasedbyhotweather,hotshowers,hottubs,andalcoholingestion.—Clientshouldnotabruptlydiscontinuemedicationorchangedosagewithoutconsultinghealthcareprovider.Abruptwithdrawalcancausereboundhypertension.—Encouragealow-sodiumdietandweightmaintenanceorreduction.—Discourageuseofalltobaccoproducts.—Haveclientreportunpleasantsideeffectsrelatedtosexualdysfunction.—Adviseclientnottotakeover-the-countercoughmedicationsordecongestantsthatcontainpseudoephedrine;thesemedicationscauseanincreaseinBP.
TEST ALERT: Observe for effects of medications. Evaluate client’s use of medications.
Memory Notebook of Nursing: Pharmacology and Diagnostics, ed 2, Ingram, Texas, 2009,
Nursing Education Consultants.
242 CHAPTER 11 Vascular System
Appendix 11-6 MEDICATIONS USED FOR TREATMENT OF SHOCK
General Nursing Implications—Mostoftenlimitedtocriticalcaresettings;constantmonitoringisrequired.—AdministeredIVindilutedsolutionbyinfusionpump.—MonitorIVinfusionsiteclosely;leakageintotissuemaycausetissuesloughing.—ContinuousECGmonitoring;observeclientcloselyforcardiacdysrhythmias.—Monitorurinaryoutputeveryhour.—MedicationsshouldnotbeadministeredtoclientsreceivingMAOIsortricyclicantidepressants.—PrimaryresponsibilityofPNistomonitorclientandkeepRNandHCPcloselyadvisedofclient’sresponse.