chapter

Patient Management: Cardiovascular System

18

MARLA DE JONG ■ KENNETH REMPHER ■ DULCE OBIAS-MANN ■ CONRAD GORDON*

PHARMACOLOGICAL THERAPY Fibrolytics, Anticoagulants, and Platelet Inhibitors Fibrinolytics Anticoagulants Platelet Inhibitors Antidysrhythmics Class I Antidysrhythmic Drugs Class II Antidysrhythmic Drugs Class III Antidysrhythmic Drugs Class IV Antidysrhythmic Drugs Unclassified Antidysrhythmic Drugs Inotropes Dopamine Dobutamine Epinephrine Isoproterenol Norepinephrine Amrinone Milrinone Vasodilators Nitrates Nitroprusside Sodium Angiotensin-Converting Enzyme Inhibitors Antihyperlipidemics PERCUTANEOUS CORONARY INTERVENTIONS AND PERCUTANEOUS BALLOON VALVULOPLASTY Percutaneous Coronary Interventions Historical Background Physiological Principles Comparisons Between PTCA and CABG Diagnostic Tests for PTCA and CABG Patient Selection Equipment Features

Indications for and Contraindications to Percutaneous Transluminal Coronary Angioplasty Procedure Results Assessment and Management Complications Other Interventional Cardiology Techniques Percutaneous Balloon Valvuloplasty Historical Background Pathophysiology of Stenotic Valves Diagnostic Tests for Percutaneous Balloon Valvuloplasty and Valve Replacement Equipment Features Indications for and Contraindications to Percutaneous Balloon Valvuloplasty Procedure Results Assessment and Management INTRA-AORTIC BALLOON PUMP COUNTERPULSATION AND MECHANICAL CIRCULATORY SUPPORT Intra-aortic Balloon Pump Counterpulsation Physiological Principles Equipment Features Indications for Intra-aortic Balloon Pump Counterpulsation

Contraindications to Intra-aortic Balloon Pump Counterpulsation Procedure Interpretation of Results Assessment and Management Complications Specific to Intraaortic Balloon Pump Therapy Mechanical Circulatory Support Physiological Principles Devices Nursing Implications Complications Associated With Intra-aortic Balloon Pump Therapy and Circulatory Support Bleeding Thromboembolic Events Right Ventricular Failure Infection Dysrhythmias Nutritional Deficits Psychosocial Factors MANAGEMENT OF DYSRHYTHMIAS Cardioversion Procedure Radiofrequency Catheter Ablation Indications for Ablation Procedure Nursing Management Cardiac Pacemakers Indications for Cardiac Pacing The Pacemaker System Temporary Pacing Systems Pacemaker Functioning The Pacemaker Code Pacing Modes Pacemaker Malfunction Pacemaker Complications Nursing Management

*The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Air Force or the Department of Defense.

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CHAPTER 18

Implantable Cardioverter– Defibrillators Indications for Implantable Cardioverter–Defibrillators The Implantable Cardioverter– Defibrillator System Implantable Cardioverter–Defibrillator Functioning The Implantable Cardioverter– Defibrillator Code Nursing Management

CARDIOPULMONARY RESUSCITATION Causes of Cardiopulmonary Arrest Assessment and Management of the Patient in Cardiopulmonary Arrest Determine Responsiveness Position the Patient Airway Breathing Circulation

objectives Based on the content in this chapter, the reader should be able to: ■ Compare and contrast commonly used fibrinolytics, anticoagulants, and platelet inhibitors used to affect the thrombotic process. ■ Describe the four classes of antidysrhythmic drugs. ■ Explain how inotropic drugs improve myocardial function. ■ Discuss the rationale for using angiotensinconverting enzyme inhibitor drugs for patients with cardiovascular disease. ■ Compare and contrast the four major classes of antihyperlipidemic drugs. ■ Compare and contrast the indications and contraindications for percutaneous coronary interventions (PCI), including percutaneous transluminal coronary angioplasty (PTCA), intracoronary stenting, directional coronary atherectomy (DCA), laser, brachytherapy, and percutaneous balloon valvuloplasty (PBV). ■ Summarize interventions for complications associated with PCI procedures. ■

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Patient Management: Cardiovascular System

List potential nursing diagnoses and the interventions for each diagnosis in the patient undergoing an interventional cardiology procedure. Describe the physiological effect of intra-aortic balloon pump (IABP) counterpulsation therapy. Explain indications for and contraindications to IABP therapy. Describe a ventricular assist device and its indications and mechanism of action.

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Role of Resuscitation Team Members Equipment Used in Cardiopulmonary Arrest Medications Defibrillation Automated External Defibrillator Transcutaneous Pacing Therapeutic Hypothermia Family Presence in Cardiac Arrest Situations

Discuss nursing interventions for the patient receiving IABP therapy or ventricular circulatory assistance. Describe the indications, procedure, and nursing management for cardioversion and radiofrequency catheter ablation. Describe the components of the pacing system and pacemaker functioning. Use the pacemaker code to describe modes of pacing. Explain complications of pacing and appropriate interventions. Discuss the nursing management of the patient with a pacemaker. Describe the indications for an implantable cardioverter–defibrillator (ICD). Describe the ICD system and its functioning. Explain the nursing management of a patient with an ICD. Describe causes of cardiopulmonary arrest. Explain steps of cardiopulmonary resuscitation. Discuss roles of members of the resuscitation team. Explain indications, procedure, and nursing management for defibrillation. Discuss the rationale for using hypothermia as part of cardiopulmonary arrest management. Describe pros and cons of having family members present in a cardiopulmonary arrest situation.

294

PART IV

CARDIOVASCULAR SYSTEM

Pharmacological Therapy Cardiovascular disease continues to be the leading cause of death in the United States. However, recent and remarkable pharmacological advances have reduced morbidity and mortality related to cardiovascular disease. Critical care nurses are responsible for preparing and administering potent drugs that affect the patient’s cardiovascular function. Furthermore, nurses continuously evaluate the effects of these drugs and use detailed patient assessment data to guide the titration of these drugs. This section summarizes drugs that are commonly used in critical care settings to treat cardiovascular disease. Recent research data are included to provide a scientific basis for drug therapy. Pharmacotherapy advances continually occur; therefore, changes in drug therapy are common. Critical care nurses frequently use current drug books or guides because before administering drugs, nurses must know the drug’s effects, contraindications, dosage and method of administration, and adverse effects. Finally, many patients require treatment with numerous cardiovascular drugs; therefore, it is important to consider how drugs interact with other drugs.

FIBROLYTICS, ANTICOAGULANTS, AND PLATELET INHIBITORS Atherosclerotic plaque rupture or vascular endothelium damage initiates a complex platelet reaction, consisting of adhesion, activation, and aggregation. The platelet aggre-

gate accelerates thrombin production through the coagulation cascade. When thrombin, a potent agonist for further platelet activation and coagulation cascade activity, converts fibrinogen to fibrin, a nonsoluble fibrin thrombus forms. For further information about the coagulation process, see Chapter 45. An arterial thrombus may transiently or persistently occlude coronary artery blood flow, causing acute coronary syndrome (ACS). Fibrinolytic, anticoagulant, and platelet inhibitor drugs affect different phases of the thrombotic process.

Fibrinolytics Fibrinolytic agents are indicated for patients with acute ST segment elevation myocardial infarction. Fibrinolytic drugs are not effective for patients with ACS without ST segment elevation, a posterior wall acute myocardial infarction (AMI), or a new left bundle branch block. Fibrinolytic agents either directly or indirectly convert plasminogen to plasmin, which in turn lyses the thrombus. The goal of fibrinolytic therapy is to dissolve the thrombus, reestablish coronary blood flow, minimize infarct size, preserve left ventricular function, and reduce morbidity and mortality.1 Table 18-1 summarizes commonly used fibrinolytic agents. Many researchers continue to evaluate fibrinolytic agents, and numerous multicenter, randomized fibrinolytic trials have shown that fibrinolytic therapy significantly reduces mortality from AMI.2 The Thrombolysis in Myocardial Infarction (TIMI) 10B trial found that a 40-mg dose

table 18-1 ■ Fibrinolytic Drugs Alteplase

Reteplase

Tenecteplase

Streptokinase

Action

Binds to fibrin in a thrombus and converts plasminogen to plasmin

Catalyzes the cleavage of plasminogen to generate plasmin

Binds to fibrin and converts plasminogen to plasmin

Binds with plasminogen to produce a complex that converts plasminogen to plasmin

Indications

AMI Acute ischemic stroke Acute, massive PE Unlabeled use: to clear thrombi in central venous catheters (2 mg into blocked catheter)

AMI

AMI

AMI Acute PE Acute, extensive deep venous thrombosis Acute arterial thrombosis or embolism Occlusion of ateriovenous cannulae

Dose

100 mg IV over 90 min (15 mg IV bolus; 50 mg IV over 30 min; 35 mg IV over 60 min)

10 U + 10 U IV bolus (each 10 U given over 2 min; second bolus given 30 min after first bolus)

Weight-based dose IV over 5 sec: >60 kg = 30 mg ≥60 to