Kaplan's Essentials of Cardiac Anesthesia E-Book

Joel A. Kaplan

• Publisher: Elsevier
• Year: 2017
• ISBN:
  9780323512084
• Edition: 2
• Topic: Medicine
• Subtopic: Anesthesiology & Pain Management

• Trusted authorities deliver the key cardiac anesthesia knowledge you need to know.
• A concise, user-friendly format and key points boxes in each chapter help you quickly locate crucial information.
• Annotated references guide you to the most practical additional resources.
• A portable size and clinical emphasis facilitates and enhances bedside patient care.

• Designed as a companion to Kaplan's Cardiac Anesthesia.
• Includes new topics vital to the current practice of cardiac anesthesiologists, such as transesophageal echocardiography; percutaneous valve procedures; new pacemakers and automatic internal defibrillators used for cardiac resynchronization therapy; left ventricular assist devices and extracorporeal membrane oxygenation therapy of heart failure; and patient safety issues.
• Focuses on today's most current and relevant therapies, including New Cardiac Drugs, and Heart Mate, Heart Ware, and Impella LVADs.
• Describes care of the cardiac patient in Hybrid Operating Rooms, Catheterization Laboratories, and Electrophysiology Laboratories, as well as the Cardiac Operating Rooms.
• Perfectly suited for residents, fellows, nurse anesthetists and anesthesiologists in practice.

Section IV

Anesthesia for Cardiac Surgical Procedures

Outline

Chapter 14 Anesthesia for Myocardial Revascularization

Chapter 15 Valvular Heart Disease Replacement and Repair

Chapter 16 Congenital Heart Disease in Adults

Chapter 17 Thoracic Aorta

Chapter 18 Uncommon Cardiac Diseases

Chapter 19 Anesthesia for Heart, Lung, and Heart-Lung Transplantation

Chapter 20 Pulmonary Thromboendarterectomy for Chronic Thromboembolic Pulmonary Hypertension

Chapter 21 Procedures in the Hybrid Operating Room

Chapter 22 Mechanical Assist Devices for Heart Failure

Chapter 23 Reoperative Cardiac Surgery

Chapter 24 Patient Safety in the Cardiac Operating Room

Chapter 14

Anesthesia for Myocardial Revascularization

Alexander J.C. Mittnacht MD, Martin J. London MD, John D. Puskas MD, Joel A. Kaplan MD, CPE, FACC

Key Points

1. Guideline updates emphasize the efficacy of surgical approaches to myocardial revascularization in patients with multivessel coronary artery disease.

2. Perioperative risk reduction includes careful consideration of all of the patient's relevant antihypertensive, antiplatelet, and antianginal medications.

3. Significant valvular abnormalities in patients scheduled for coronary revascularization should be evaluated and considered in surgical planning.

4. Off-pump coronary artery bypass surgery is an established alternative to on-pump myocardial revascularization (ie, coronary artery bypass grafting [CABG]). The choice and outcomes of either approach are highly surgeon dependent. Despite apparent advantages of avoiding cardiopulmonary bypass (CPB), evidence from large prospective trials enrolling mostly low-risk patients has not shown clear reductions in mortality with an off-pump approach.

5. Possible indications for pulmonary artery catheter use in CABG surgery include patients with pulmonary hypertension, right-sided heart failure, or severely impaired ventricular function, particularly those who require postoperative cardiac output monitoring.

6. Fast-tracking, including early extubation and mobilization, has been almost universally adopted for patients undergoing myocardial revascularization.

7. Anesthetic drugs, especially inhaled anesthetic agents, may help to ameliorate myocardial injury associated with CPB and aortic cross-clamping by their preconditioning and postconditioning effects. However, the magnitude of these effects on outcome remains controversial.

The role of the cardiac anesthesiologist in the perioperative care of patients undergoing myocardial revascularization continues to evolve. Achievements of the past two decades include providing safe anesthesia that allows rapid recovery and optimizing monitoring that includes the establishment of transesophageal echocardiography (TEE) as a standard of care in the cardiac operating room. More recent developments in patient care include the introduction of a perioperative surgical home, which affects the management of patients undergoing myocardial revascularization. The anesthesiologist is vitally important in the multidisciplinary approach to patient care. Optimal perioperative care requires close collaboration and coordination between the various specialties involved on the heart team. The process begins with the decision to proceed to surgery and continues with preoperative optimization, state-of-the-art perioperative and postoperative care, and rehabilitation after hospital discharge. Beyond safe anesthesia technique, the anesthesiologist must be well versed in all areas of perioperative management for patients with coronary artery disease (CAD). This includes advances in pharmacologic risk reduction, new surgical techniques, and anesthetic management and monitoring techniques to improve patient outcomes.

Epidemiology

According to the American Heart Association Heart Disease and Stroke Statistics, most recently updated in 2014, epidemiologic data relevant to cardiovascular disease can be summarized as follows. Overall rates of death attributable to cardiovascular disease have declined 31%; for CAD, there was a 39.2% decrease from 2000 to 2010. This was partially attributed to improvements in acute treatment of patients with acute coronary syndromes (ACSs), secondary preventive therapies after myocardial infarction (MI), treatment of acute heart failure (HF), revascularization of chronic CAD, and other preventive therapies. However, the prevalence remains high, with cardiovascular disease accounting for 31.9% of all deaths in the United States. Based on current estimates, by 2030 43.9% of the US population will have some form of cardiovascular disease. Similarly, 15.4 million individuals had CAD in 2010; and ischemic heart disease causes approximately one of every six deaths in the United States. In 2010, 379,559 Americans died of CAD, and statistically, every 34 seconds one person in the United States has a coronary event.

Between 2000 and 2010 the total number of inpatient cardiovascular procedures in the United States increased by 28%, with a total of 7,588,000 cardiovascular procedures performed in 2010. In 2010 an estimated 219,000 patients underwent 397,000 coronary artery bypass graft (CABG) procedures (Fig. 14.1). The in-hospital mortality rate for CABG declined by 50% despite an increase in the comorbidity index. CAD alone resulted in more than $44 billion in expenses, making it the most expensive condition treated. The total direct and indirect cost of cardiovascular disease and stroke was estimated to be $315.4 billion in 2010, more than for any other diagnostic group.

Fig. 14.1 Trends in cardiovascular operations and procedures from 1979 to 2010 for inpatient procedures only. PCI, Percutaneous coronary intervention. (From Mozaffarian D, Benjamin EJ, Go AS, et al. American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics: 2015 update. A report from the American Heart Association. Circulation. 2015;131:e29.)

Pathophysiology of Coronary Artery Disease

Anatomy

The anesthesiologist should be familiar with coronary anatomy if only to interpret the significance of angiographic findings. The coronary circulation and common sites for placement of distal anastomoses during CABG are shown in Figs. 14.2 through 14.4.

Fig. 14.2 Thirty-degree left anterior oblique angiographic view of the heart, which best shows the right coronary artery. Lines indicate common sites of distal vein graft anastomoses. (From Stiles QR, Tucker BL, Lindesmith GG, et al. Myocardial Revascularization: A Surgical Atlas. Boston, Little, Brown; 1976.)

Fig. 14.3 Ten-degree right anterior oblique angiographic view of the heart, which best shows the left main coronary artery dividing into the circumflex and left anterior descending arteries. Lines indicate common sites of distal vein graft anastomoses. (Modified from Stiles QR, Tucker BL, Lindesmith GG, et al. Myocardial Revascularization: A Surgical Atlas. Boston: Little, Brown; 1976.)

Fig. 14.4 Seventy-five–degree left anterior oblique angiographic view of the heart, which best shows branches of the left anterior descending and circumflex coronary arteries. Lines indicate common sites of distal vein graft anastomoses. (Modified from Stiles QR, Tucker BL, Lindesmith GG, et al. Myocardial Revascularization: A Surgical Atlas. Boston: Little, Brown; 1976.)

The right coronary artery (RCA) arises from the right sinus of Valsalva and is best seen in the left anterior oblique view on coronary cine angiography. It passes anteriorly for the first few millimeters and then follows the right atrioventricular (AV) groove and curves posteriorly within the groove to reach the crux of the heart, the area where the interventricular septum (IVS) meets the AV groove. In 84% of cases, it terminates as the posterior descending artery (PDA), which is its most important branch because it is the sole supply to the posterosuperior IVS. Other important branches are those to the sinus node in 60% of patients and the AV node in approximately 85% of patients. Anatomists consider the RCA to be dominant when it crosses the crux of the heart and continues in the AV groove regardless of the origin of the PDA. Angiographers, however, ascribe dominance to the artery—right coronary or left coronary (ie, circumflex)—that gives rise to the PDA.

The vertical and superior orientation of the RCA ostium allows easy passage of air bubbles during aortic cannulation, cardiopulmonary bypass (CPB), or open valve surgery. In sufficient volume, myocardial ischemia involving the inferior left ventricular (LV) wall segments and the right ventricle may occur (Fig. 14.5). In contrast, the near-perpendicular orientation of the left main coronary ostium makes air embolization much less common.

Fig. 14.5 The vertical and superior orientation of the right coronary artery (RCA) arising from the aortic root is identified by transesophageal echocardiography (TEE). The TEE transducer in the esophagus is at the top of the screen, and the patient's chest wall is at the bottom. Retained air preferentially enters the RCA, which may cause inferior ischemia, depending on the amount of air and the coronary perfusion pressure. Elevation of perfusion pressure using phenylephrine is often used to treat coronary air embolus. The left main coronary artery (not visible) arises at approximately 3 o'clock on this image. (Courtesy Martin J. London, MD, University of California, San Francisco, CA [www.ucsf.edu/teeecho].)

The left coronary artery arises from the left sinus of Valsalva as the left main coronary artery. It is best seen in a shallow right anterior oblique projection (see Fig. 14.3). The left main coronary artery courses anteriorly and to the left, where it divides in a space between the aorta and pulmonary artery. Its branches are the left anterior descending (LAD) artery and circumflex artery. The LAD passes along the anterior interventricular groove. It may reach only two-thirds of the distance to the apex or extend around the apex to the diaphragmatic portion of the left ventricle. Major branches of the LAD are the diagonal branches, which sup...