Essentials of Cardiac Anesthesia for Noncardiac Surgery E-Book

A Companion to Kaplan's Cardiac Anesthesia

Joel A. Kaplan

• Publisher: Elsevier
• Year: 2018
• Print ISBN: 9780323567169
• eBook ISBN: 9780323567121
• Topic: Medicine
• Subtopic: Anesthesiology & Pain Management

Patients with cardiac conditions routinely present for noncardiac surgeries, requiring special protocols for perioperative assessment and management by the anesthesiologist. Essentials of Cardiac Anesthesia for Noncardiac Surgery: A Companion to Kaplan's Cardiac Anesthesia provides current, easily accessible information in this complex area, ideal for general anesthesiologists and non-cardiac subspecialists. From preoperative assessment through postoperative care, this practical reference covers all perioperative approaches to today's patients with cardiac conditions.- Provides guidance on the anesthetic diagnosis and management of the full range of cardiac lesions, helping minimize adverse outcomes and reduce complications for patients with common, complex, or uncommon cardiac conditions.- Includes complete coverage of echocardiography and current monitoring techniques needed for thorough perioperative assessment – all from the anesthesiologist's perspective.- Discusses safe and effective perioperative anesthetic management of patients presenting with advanced levels of cardiac care such as drug-eluting stents, multiple antiplatelet drugs, ventricular assist devices, multiple drugs for end-stage heart failure, and implanted electrical devices that produce cardiac resynchronization therapy, as well as patients with complicated obstetric problems or other significant cardiovascular issues.- Features a concise, easy-to-navigate format and Key Points boxes in each chapter that help you find answers quickly.

Section II

Anesthesia for Noncardiac Surgery

Outline

• Chapter 9 Cardiovascular Monitoring in Noncardiac Surgery
• Chapter 10 Echocardiography in Noncardiac Surgery
• Chapter 11 Cardiovascular Pharmacology in Noncardiac Surgery
• Chapter 12 General, Regional, or Monitored Anesthesia Care for the Cardiac Patient Undergoing Noncardiac Surgery
• Chapter 13 Vascular Surgery Endovascular and Open Surgery
• Chapter 14 The Cardiac Patient for Thoracic Noncardiac Surgery
• Chapter 15 Anesthesia for Cardioversion and Electrophysiologic Procedures
• Chapter 16 Cardiac Patients Requiring Emergent Noncardiac Surgery
• Chapter 17 Cardiac Considerations During Orthotopic Liver Transplantation
• Chapter 18 The Pregnant Patient With Cardiac Disease
• Chapter 19 Goal-Directed Fluid Therapy, Perioperative Pain Management, and Enhanced Recovery

Chapter 9

Cardiovascular Monitoring in Noncardiac Surgery

Gerard R. Manecke Jr, MD, Timothy M. Maus MD

Keywords

hemodynamic monitoring; electrocardiogram; central venous pressure; cardiac output; goal-directed therapy

Key Points

1. 1. Excellent cardiac and hemodynamic management is essential to achieving good outcomes in patients with cardiovascular disease, particularly those undergoing high-risk noncardiac surgery.
2. 2. Much cardiovascular information can be obtained from the standard American Society of Anesthesiologists monitors, including those usually associated with evaluation of respiratory function (pulse oximetry, capnography). The pulse oximeter plethysmograph can be used to assess adequacy of the peripheral circulation; expired capnography reflects pulmonary blood flow and cardiac output.
3. 3. The five-electrode electrocardiographic system commonly used perioperatively allows rapid diagnosis of a wide variety of cardiac abnormalities, including rhythm disturbances, conduction abnormalities, myocardial ischemia, myocardial infarction, and electrolyte abnormalities.
4. 4. Although often unreliable as an intravascular volume monitor, invasive monitoring of the central venous pressure (CVP) can be useful in the management of cardiac patients. CVP provides information about the systolic and diastolic performance of the heart in response to fluid administration, as well as waveform information that can aid in the diagnosis of abnormalities such as tricuspid regurgitation and junctional rhythms.
5. 5. The pulmonary artery catheter is a very powerful monitor, providing a wide array of data that include right-sided pressures, cardiac performance, and a surrogate for left atrial pressure (pulmonary capillary wedge pressure). Although its use has declined in noncardiac surgery, it is still very useful in select patients such as those with pulmonary hypertension or right ventricular failure. It is also useful for monitoring left ventricular function and solving hemodynamic problems when transesophageal echocardiography is unavailable.
6. 6. Minimally invasive and noninvasive means of continuously monitoring arterial blood pressure, as well as cardiac output and dynamic parameters such as stroke volume variation, are now widely used. They are particularly useful in cardiac patients undergoing high-risk surgery. They facilitate perioperative goal-directed therapy (PGDT), enhanced recovery from surgery, and rapid diagnosis of hemodynamic problems.
7. 7. Noninvasive monitors that assess tissue oxygenation, pH, and perfusion are likely to be further developed and used. Because the purpose of circulation is tissue perfusion, it is logical to quantify tissue perfusion and oxygenation. Somatic near-infrared spectroscopy is currently used for this purpose in PGDT algorithms.

Perioperative care includes effective cardiac, hemodynamic, and fluid management. Excellent cardiovascular management is particularly important in patients undergoing major noncardiac surgery and those with preexisting cardiovascular disease. It is only with meaningful, accurate monitoring that appropriate cardiac, hemodynamic, and fluid therapy can be provided. This chapter focuses on the various means by which the cardiac and hemodynamic status can be monitored, ranging from noninvasive to highly invasive techniques. Other indicators of cardiovascular function, such as urine output, are discussed as well. Echocardiography is not discussed here; it is presented in Chapter 10.

Standard American Society of Anesthesiologists Monitors

Most of the standard American Society of Anesthesiologists (ASA) monitors provide information about the cardiovascular system (Box 9.1). Electrocardiogram (ECG), arterial blood pressure, heart rate, and intraarterial pressure tracings are obviously useful, but those used to monitor respiratory function, such as end-tidal carbon dioxide (ETCO₂) and pulse oximetry with its plethysmograph tracing, can also provide valuable cardiovascular information. The standard ASA monitors are listed in Table 9.1.

Box 9.1

Basic Perioperative Monitors of Cardiovascular Function

• • Electrocardiogram
• • Heart rate
• • Noninvasive blood pressure
• • Pulse oximetry with plethysmograph analysis
  • • Perfusion index
  • • Pleth variability index
• • End-tidal carbon dioxide
  • • Pulmonary blood flow
• • Auscultation of heart sounds
  • • Amplitude and frequency of S₁ for inotropic state
  • • Amplitude and frequency of S₂ for systemic blood pressure

Table 9.1

Standard American Society of Anesthesiologists Monitoring

Category	Monitor	Frequency
Circulation	Electrocardiogram^a	Continual
	Arterial blood pressure^a	Every 5 min (minimum)
	Heart rate^a	Every 5 min (minimum)
	Circulatory function (one of the following)^a:
	• Auscultation of heart sounds^a
	• Intraarterial pressure tracing^a	Continual
	• Ultrasound of peripheral pulse^a
	• Pulse plethysmography or oximetry^a
Ventilation	End-tidal carbon dioxide^a	Continual
Oxygenation	Inspired gas	Continual
	Pulse oximetry^a	Continual
	Patient color^a
Temperature	Temperature probe	Immediately available, when changes in body temperature are anticipated

^aParameters that are useful in cardiovascular monitoring.

From American Society of Anesthesiologists Standards for Basic Monitoring, http://www.asahq.org.

Electrocardiogram

The ECG is a mainstay for monitoring cardiac status. Continuously monitoring cardiac electrical activity, it provides heart rate and rhythm data, as well as assessment of cardiac conduction (PR interval, QRS duration) and repolarization (ST segment, T-wave morphology, and QT interval). The normal morphologies of the ECG signal and the ECG intervals are shown in Fig. 9.1.

Fig. 9.1 Electrocardiographic morphology of one cardiac cycle and intervals.

A three-lead system, using three or four electrodes (right arm, left arm, left leg, ground), allows monitoring of limb leads I, II, or III, providing primarily rhythm and conduction data. This can suffice for healthy patients, but a five-electrode system (right arm, left arm, left leg, precordial, ground) is usually used perioperatively and in intensive care units. This system allows simultaneous monitoring of a limb lead (usually lead II) and a precordial “V” lead that enhances the detection of myocardial ischemia. The sensitivity for detecting myocardial ischemia when using a combination of leads II and V₅ has been reported to be 80%. The V lead can be placed according to the particular area of interest, ranging from anterior (V₁) to lateral (V₆) (Fig. 9.2), with V₃ to V₅ generally being the most sensitive for anterior-lateral myocardial ischemia (lead II is used for inferior wall ischemia).

Fig. 9.2 Placement of the five-electrode system commonly used in operating rooms and intensive care units. The precordial lead (V) can be placed according to the area of interest, with the V₃ to V₅ positions generally being the most sensitive for myocardial ischemia.

Myocardial ischemia most often manifests as ST-segment depression, although elevated ST segments, change in T-wave morphology, new conduction defects, or frequent premature ventricular contractions may also be signs of myocardial ischemia. ECG monitoring systems have automated digital signal processing to continuously display heart rate, QT interval, and ST-segment depression or elevation, as well as alarm systems for these parameters.

Abnormal rhythms, such as sinus bradycardia and tachycardia, junctional rhythms, atrial fibrillation, right and left bundle branch blocks, and heart block, are not uncommon in cardiac patients. All these abnormalities can be detected using a five-electrode system (Tables 9.2 and 9.3). Whereas a limb lead such as lead II is preferred for conduction and rhythm detection, the precordial leads are preferred for diagnosis of myocardial ischem...

Table of contents

• Cover image
• Title Page
• Table of Contents
• Copyright
• Dedication
• Contributors
• Preface
• Section I Perioperative Medicine
• Section II Anesthesia for Noncardiac Surgery
• Section III Critical Care Medicine
• Index