Anesthesia for Noncardiac Surgery in Patients with Congenital Heart Disease

Introduction

• CHD is the most common form of congenital abnormality, occurring in approximately 1% of live births.^1,2 Advances in diagnosis, monitoring, procedural and surgical interventions, as well as organization of care into specialized teams and centers, have shifted mortality away from early childhood and towards adulthood, even for those with more severe CHD.^1,2 This translates into more children and adults undergoing noncardiac surgery.
• Patients with CHD are generally at higher risk for cardiac arrest, perioperative mortality, and major morbidity compared to those without CHD.^3-7 CHD severity, young age less than 1 year, and patient comorbidities are the predominant predictors of mortality.^3,4
• Data from the Pediatric Perioperative Cardiac Arrest Registry from 1994 to 2005 demonstrated that single ventricle patients, as well as those with unrepaired CHD, were more likely to experience cardiac arrest, and that this most frequently occurred in the general operating room.⁵
• Mortality trends for children with CHD undergoing noncardiac surgical procedures at children’s hospitals are improving, while those without CHD remain constant.³
• Adults with CHD comprise an increasing fraction of all noncardiac surgical admissions, with increased perioperative morbidity, length of stay, and higher hospital costs compared to the non-CHD cohort.⁶
• The most frequent noncardiac surgical procedures that CHD patients undergo are otolaryngology and general surgery procedures for children, and general surgery and orthopedic surgery for adults.^3,6
• Children with complex CHD are more likely to travel to a hospital with a specialized cardiac program.⁷ The majority of adult CHD patients are cared for in nonteaching hospitals.⁶

Preoperative Considerations

• Depending on the severity of CHD and the surgical risk, patients with CHD may require comprehensive team planning. Those with unrepaired CHD or residual lesion burden and compromised cardiovascular status require individualized care at a specialized center.^3,4

Cardiac Risk Stratification

• In 2023, the American Heart Association Council on Lifelong Congenital Heart Disease and Heart Health in the Young and the Council on Cardiovascular Radiology and Intervention published a scientific statement on perioperative considerations for pediatric patients with CHD undergoing noncardiac procedures.⁴ Their suggested management algorithm, based on the American College of Surgeons National Surgical Quality Improvement Program (Table 1) classifications for CHD, is shown in Figure 1.
• Patients with severe CHD or single-ventricle physiology should be cared for at centers with ICU capabilities by pediatric cardiac anesthesiologists or pediatric anesthesiologists with expertise in the care of patients with CHD, with a pediatric cardiac anesthesiologist available for consultation.
• Patients with major CHD are further risk-stratified into high and low-risk patient groups.
• The new 2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMRR/SVM guideline for perioperative cardiovascular management of noncardiac surgery (adults) includes elevated-risk CHD as a perioperative risk modifier.
  • Adult patients with intermediate- to elevated-risk CHD should have a preoperative consultation with an adult CHD specialist before elective noncardiac surgery.
  • Low-risk patients are defined as those with isolated, small CHD lesions; repaired CHD with no residual shunt; bicuspid aortic valve and aortopathy; and New York Heart Association functional class I with normal exercise capacity, no chamber enlargement on echocardiography, no pulmonary hypertension, and no arrhythmia.⁸

Preoperative Assessment and Planning

• A comprehensive preoperative evaluation for patients with CHD should include a review of the native anatomy and history of palliations/repairs or endocarditis, as well as the presence of current cardiac symptoms, residual lesions, arrhythmias, pulmonary hypertension, hypoxemia, and/or end-organ dysfunction.⁸
• Special attention to the presence of systolic or diastolic dysfunction, moderate to severe valvular dysfunction, aortopulmonary shunt compromise, and severe systemic outflow tract obstruction is imperative.⁴
• Hydration status with carefully planned fasting times, presence of recent respiratory infections, history of prior anesthetic exposure, noting any complications, difficult airway risk, and expected impact of the surgery on underlying hemodynamics and pathophysiology should be fully assessed.⁴
• Multidisciplinary planning should address the prevention of complications related to the patient’s underlying cardiovascular pathophysiology, the need for endocarditis prophylaxis or bubble precautions, the management of periprocedural anticoagulation and prevention of venous thrombosis, the identification of vascular access issues, and the assessment of renal and hepatic function to guide appropriate drug dosing.⁸
• Electrocardiograms, chest radiographs, echocardiograms, diagnostic or interventional catheterization data, cardiac magnetic resonance images, and computed tomography images should be reviewed. Cardiac diagrams, reconstructions, or 3D printed models of the patient’s heart are particularly useful in complex CHD. If the patient has developed new symptoms since the last evaluation or imaging study, new diagnostic studies may be warranted.
• Preoperative laboratory work should be obtained based on symptoms, comorbidities, medication use, and the planned surgical procedure, with attention to risk of hemorrhage, temperature dysregulation, and electrolyte disturbance.⁴
• Approximately 30% of CHD patients have extracardiac anomalies, which are often related to associated chromosomal abnormalities.⁹ Genetic syndromes related to CHD (most commonly Trisomy 21, Noonan, 22q11.2 deletion, and Turner) each have their own extracardiac conditions and clinical risk profile with a variety of perioperative considerations including cognitive or developmental delay, airway difficulty, autonomic nervous system dysfunction, extracardiac organ dysfunction, electrolyte disturbances, and abnormal vasculature leading to difficult intravenous and arterial access.

Perioperative Considerations

Monitoring

• Understanding the risks involved with the proposed surgical procedure and the associated physiologic stress responses, as well as the severity of CHD and functional status, will guide the selection of monitor placement.
• In addition to standard American Association of Anesthesiologists monitors, invasive monitoring with arterial line, central venous lines, pulmonary artery catheters, or transesophageal echocardiography may be indicated for procedures associated with significant blood loss, fluid shifts, core temperature variation, or deformation of important vascular structures or organs.

Airway Management

• Pulmonary comorbidities, including congenital airway malformations, difficult airway, tracheomalacia, and laryngomalacia, are present in many patients with CHD.⁴
• Careful preoperative evaluation, including a review of previous attempts at mask ventilation or endotracheal intubation, is important as even brief episodes of hypoxia or hypercarbia may not be tolerated.
• Immediate access to difficult airway equipment should be ensured. Apneic oxygenation during airway attempts (i.e., via nasal cannula) may be considered in higher-risk patients.

Device Management

• Patients with CHD may have pacemakers, internal cardioverter-defibrillators (Link) and/or ventricular assist devices (VAD).
• When caring for any patient with cardiac implantable electronic devices, the anesthesiologist must be familiar with perioperative management, including assessing the need for magnet application or device reprogramming based on potential electromagnetic interference and the patient’s device type, implantation indication, and device interrogation.
• CHD patients with a VAD are at higher risk of complications during noncardiac surgery and require a multidisciplinary approach to care at specialized centers, with special attention to anticoagulation management and infection prevention. These patients should be considered at high risk for having a “full stomach” due to altered gastrointestinal function and potential mechanical compression.

Infectious Endocarditis (IE) Prophylaxis¹⁰

• Certain CHD patients are at high risk for IE (Table 2).
• The 2007 AHA endocarditis prophylaxis guidelines recommend that antibiotics be given to high-risk patients for the following noncardiac procedures: dental procedures involving manipulation of gingiva, periapical teeth, or perforation of oral mucosa; procedures involving the respiratory tract; and procedures on infected skin, skin structures, or musculoskeletal tissue.¹
• Please see the OA summary on subacute bacterial endocarditis prophylaxis. Link
• Recommended antibiotic regimens are listed in Table 3.

Bubble Precautions

• Bubble precautions are important to reduce the risk of systemic air embolization, particularly in patients with right-to-left shunts. Proper intravenous line management, careful monitoring, and patient positioning may be important management strategies during procedures with a heightened risk of air embolism.

Laparoscopy

• Laparoscopic procedures and their potential for systemic carbon dioxide embolization is of particular concern in patients with right-to-left shunts from intracardiac anatomy or collateral circulation sources.
• A high level of vigilance during intra-abdominal insufflation and maintenance of pressure is prudent, as excessive pressure may compromise cardiac output through impedance of venous return and increases in mean airway pressure.⁴

Anticoagulation

• Postoperative thrombosis is highest in patients with cyanotic heart disease, especially in single ventricle physiology (SVP).⁴
• A multidisciplinary discussion on the appropriate timing of resumption of anticoagulation is imperative in these patients to balance the relative risks of postsurgical bleeding versus thromboembolic events.

Management Principles for Specific Patient Groups

Left-to-Right Shunts

• Simple left-to-right shunts such as atrial septal defect, ventricular septal defect, and patent ductus arteriosus are the most common forms of CHD. Measures taken to reduce the shunt fraction during anesthetic care to avoid worsening of pulmonary overcirculation may include limiting the fraction of inspired oxygen, maintaining normocarbia, and judicious use of intravenous fluids. Nitrous oxide should be avoided if there is an element of dynamic pulmonary hypertension.
• If unrepaired, these shunts may lead to pulmonary hypertension, ventricular hypertrophy, and eventually Eisenmenger Syndrome, which delineate their own anesthetic considerations.

Links to VSD and PDA keywords.

Single-Ventricle Physiology

• The risk associated with noncardiac surgery is elevated in patients with SVP, having been reported to be as high as nearly 12% in the intraoperative and early postoperative periods.⁴
• Risks associated with the various stages of palliation are less well characterized, but the physicians caring for the SVP patient should understand the anatomy and specific considerations associated with each stage.
• In SVP, ventricular output is the sum of pulmonary and systemic blood flow, and the distribution to each depends on relative resistance to flow. Patients with unrepaired SVP and palliated SVP are at risk of hemodynamic instability and cardiovascular collapse if balanced pulmonary and systemic blood flow is not maintained. Fontan patients, who rely on an in-series pulmonary and systemic circulation, may not tolerate positive-pressure ventilation due to its potential to impede venous return and forward flow; consideration of avoiding general anesthesia in favor of less invasive anesthetic techniques whenever possible is recommended.

Links to SVP and Fontan keywords.

Unrepaired Tetralogy of Fallot

• Patients with unrepaired tetralogy of Fallot are at risk for worsening cyanosis, hypoxemia, and cardiovascular collapse in the perioperative period. The degree of vulnerability is primarily related to the stability of their source of pulmonary blood flow and the degree of right ventricular outflow tract obstruction.
• Acute cyanosis/hypoxemia or “tet spells” can occur at any time due to increased right-to-left shunting caused by fluctuations in pulmonary vascular resistance (PVR) and systemic vascular resistance. Still, particularly vulnerable periods are during anesthetic induction and before surgical stimulation.¹¹
• Maneuvers to prevent and/or treat spells are aimed at relieving the infundibular muscle spasm and reversing the shunt: increase the fraction of inspired oxygen, administer phenylephrine and/or esmolol, administer intravenous fluids, apply abdominal compression, and increase the depth of anesthesia with a volatile agent.

Link to TOF keyword.

Pulmonary Hypertension

• Patients with pulmonary hypertension have a significantly elevated risk for perioperative morbidity and mortality, with the incidence of perioperative cardiac arrest as high as 5% and perioperative death as high as 1.5%.⁴
• Prevention of acute pulmonary hypertensive crisis, in which abrupt elevations in PVR lead to right ventricular dysfunction, hypotension, and decreased cardiac output, should include avoidance of hypothermia, acidosis, hypoxia, hypercarbia, and significant pain or stress.
• Select pulmonary vasodilators, such as inhaled nitrous oxide or phosphodiesterase inhibitors, and inotropic therapy to support the right heart may be indicated in certain patients.

Link to CHD: PHTN keyword.