Key Points
- 1.
Because of successes in treating congenital cardiac lesions, there are currently as many or more adults than children with congenital heart disease (CHD).
- 2.
These patients may require cardiac surgical intervention for primary cardiac repair, repair following prior palliation, revision of repair due to failure or lack of growth of prosthetic material, or conversion of a suboptimal repair to a more modern operation.
- 3.
Noncardiac anesthesiologists will see these patients for a vast array of ailments and injuries requiring surgery.
- 4.
If at all possible, noncardiac surgery on adult patients with moderate-to-complex CHD should be performed at an adult congenital heart center with the consultation of an anesthesiologist experienced with adult CHD.
- 5.
Delegation of one anesthesiologist as the liaison with the cardiology service for preoperative evaluation and triage of adult patients with CHD is helpful.
- 6.
All relevant cardiac tests and evaluations should be reviewed in advance.
- 7.
Sketching out the anatomy and path(s) of blood flow is often an easy and enlightening aid in simplifying apparently very complex lesions.
Advances in perioperative care for children with congenital heart disease (CHD) over the past several decades have resulted in an ever-increasing number of these children reaching adulthood with their cardiac lesions palliated or repaired. The first paper on adult CHD (ACHD) was published in 1973. The field has grown such that several texts are now devoted to it, and a dedicated specialty society, the International Society for Adult Congenital Heart Disease ( http://www.isachd.org ), was formed in the 1990s. Each year an estimated 32,000 new cases of CHD occur in the United States and 1.5 million worldwide. More than 85% of infants born with CHD are expected to grow to adulthood. It is estimated that there are more than 1 million adults with CHD in the United States and 1.2 million in Europe, and this population is growing at approximately 5% per year; 55% of these adults remain at moderate-to-high risk, and more than 115,000 in the US have complex disease. These patients can be seen by anesthesiologists for primary cardiac repair, repair following a prior palliation, revision of repair due to failure or lack of growth of prosthetic material, or conversion of a suboptimal repair to a more modern operation ( Box 16.1 ). In addition, these adults with CHD will be seen for the other common ailments of aging and trauma that require surgical intervention. Although it has been suggested that teenagers and adults can have repair of congenital cardiac defects with morbidity and mortality approaching that of surgery done during childhood, these data are limited and may reflect only a relatively young and acyanotic sampling. Other data suggest that, in general, adults over 50 years of age represent an excessive proportion of the early postoperative mortality encountered, and the number of previous operations and cyanosis are both risk factors.
Box 16.1
Primary repair
Total correction following palliation
Revision of total correction
Conversion of suboptimal obsolescent operation into more modern repair
Heart transplantation
These patients bring with them anatomic and physiologic complexities of which physicians accustomed to caring for adults may be unaware, as well as medical problems associated with aging or pregnancy that might not be familiar to physicians used to caring for children. This has led to the establishment of the growing subspecialty of ACHD. The American College of Cardiology reviewed the available evidence and published superb guidelines for the care of these patients in 2008. A major recommendation was that adult patients with moderate or complex CHD be cared for in specialized adult congenital heart centers. An informed anesthesiologist is a critical member of the team required to care optimally for these patients. A specific recommendation was that noncardiac surgery on adult patients with moderate-to-complex CHD be done at an adult congenital heart center (regional centers) with the consultation of an anesthesiologist experienced with ACHD. In fact, one of the founding fathers of the subspecialty wrote, “A cardiac anesthesiologist with experience in CHD is pivotal…The cardiac anesthesiologist and the attending cardiologist are more important than the noncardiac surgeon.” Despite this recommendation, the majority of adult patients with CHD having ambulatory surgery appear not to be having their surgery at ACHD centers.
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General Noncardiac Issues With Longstanding Congenital Heart Disease
A variety of organ systems can be affected by long-standing CHD; these are summarized in Box 16.2 . Because congenital cardiac disease can be one manifestation of a multiorgan genetic or dysmorphic syndrome, all patients require a full review of systems and examination.
Potential Respiratory Implications
- •
Decreased compliance (with increased pulmonary blood flow or impediment to pulmonary venous drainage)
- •
Compression of airways by large, hypertensive pulmonary arteries
- •
Compression of bronchioles
- •
Scoliosis
- •
Hemoptysis (with end-stage Eisenmenger syndrome)
- •
Phrenic nerve injury (prior thoracic surgery)
- •
Recurrent laryngeal nerve injury (prior thoracic surgery; very rarely from encroachment of cardiac structures)
- •
Blunted ventilatory response to hypoxemia (with cyanosis)
- •
Underestimation of Pa co 2 by capnometry in cyanotic patients
Potential Hematologic Implications
- •
Symptomatic hyperviscosity
- •
Bleeding diathesis
- •
Abnormal von Willebrand factor
- •
Artifactually elevated prothrombin/partial thromboplastin times with erythrocytic blood
- •
Artifactual thrombocytopenia with erythrocytic blood
- •
Gallstones
Potential Renal Implication
- •
Hyperuricemia and arthralgias (with cyanosis)
Potential Neurologic Implications
- •
Paradoxical emboli
- •
Brain abscess (with right-to-left shunts)
- •
Seizure (from old brain abscess focus)
- •
Intrathoracic nerve injury (iatrogenic phrenic, recurrent laryngeal, or sympathetic trunk injury)
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General Noncardiac Issues With Longstanding Congenital Heart Disease
A variety of organ systems can be affected by long-standing CHD; these are summarized in Box 16.2 . Because congenital cardiac disease can be one manifestation of a multiorgan genetic or dysmorphic syndrome, all patients require a full review of systems and examination.
Potential Respiratory Implications
- •
Decreased compliance (with increased pulmonary blood flow or impediment to pulmonary venous drainage)
- •
Compression of airways by large, hypertensive pulmonary arteries
- •
Compression of bronchioles
- •
Scoliosis
- •
Hemoptysis (with end-stage Eisenmenger syndrome)
- •
Phrenic nerve injury (prior thoracic surgery)
- •
Recurrent laryngeal nerve injury (prior thoracic surgery; very rarely from encroachment of cardiac structures)
- •
Blunted ventilatory response to hypoxemia (with cyanosis)
- •
Underestimation of Pa co 2 by capnometry in cyanotic patients
Potential Hematologic Implications
- •
Symptomatic hyperviscosity
- •
Bleeding diathesis
- •
Abnormal von Willebrand factor
- •
Artifactually elevated prothrombin/partial thromboplastin times with erythrocytic blood
- •
Artifactual thrombocytopenia with erythrocytic blood
- •
Gallstones
Potential Renal Implication
- •
Hyperuricemia and arthralgias (with cyanosis)
Potential Neurologic Implications
- •
Paradoxical emboli
- •
Brain abscess (with right-to-left shunts)
- •
Seizure (from old brain abscess focus)
- •
Intrathoracic nerve injury (iatrogenic phrenic, recurrent laryngeal, or sympathetic trunk injury)
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Cardiac Issues
The basic hemodynamic effects of an anatomic cardiac lesion can be modified by time and by the superimposed effects of chronic cyanosis, pulmonary disease, or the effects of aging. Although surgical cure is the goal, true universal cure, without residua, sequelae, or complications, is uncommon on a population-wide basis. Exceptions include closure of a nonpulmonary hypertensive patent ductus arteriosus (PDA) or atrial septal defect (ASD), probably in childhood. Although there have been reports of series of surgeries on adults with CHD, the wide variety of defects and sequelae from prior surgery make generalizations difficult, if not impossible. Poor myocardial function can be inherent in the CHD but can also be affected by long-standing cyanosis or superimposed surgical injury, including inadequate intraoperative myocardial protection. This is particularly true of adults who had their cardiac repair several decades ago when myocardial protection may not have been as good and when repair was undertaken at an older age. Postoperative arrhythmias are common, particularly when surgery entails long atrial suture lines. Thrombi can be found in these atria precluding immediate cardioversion. Bradyarrhythmias can be secondary to surgical injury to the sinus node or conducting tissue or can be a component of the cardiac defect.
The number of cardiac lesions and subtypes, together with the large number of contemporary and obsolescent palliative and corrective surgical procedures, make a complete discussion of all CHD impossible. The reader is referred to one of the current texts on pediatric cardiac anesthesia for more detailed descriptions of these lesions, the available surgical repairs, and the anesthetic implications during primary repair. Some general perioperative guidelines to caring for these patients are offered in Box 16.3 .
General
- •
The best care for both cardiac and noncardiac surgery in adult patients with congenital heart disease (CHD) is afforded in a center with a multidisciplinary team experienced in the care of adults with CHD and knowledgeable about both the anatomy and physiology of CHD and the manifestations and considerations specific to adults with CHD.
Preoperative
- •
Review most recent laboratory data, catheterization, and echocardiogram, and other imaging data. The most recent office letter from the cardiologist is often most helpful. Obtain and review these in advance.
- •
Drawing a diagram of the heart with saturations, pressures, and direction of blood flow often clarifies complex and superficially unfamiliar anatomy and physiology.
- •
Avoid prolonged fast if patient is erythrocytotic to avoid hemoconcentration.
- •
No generalized contraindication to preoperative sedation.
Intraoperative
- •
Large-bore intravenous access for redo sternotomy and cyanotic patients.
- •
Avoid air bubbles in all intravenous catheters. There can be transient right-to-left shunting even in lesions with predominant left-to-right shunting (filters are available but will severely restrict ability to give volume and blood).
- •
Apply external defibrillator pads for redo sternotomies and patients with poor cardiac function.
- •
Appropriate endocarditis prophylaxis (orally or intravenously before skin incision).
- •
Consider antifibrinolytic therapy, especially for patients with prior sternotomy.
- •
Transesophageal echocardiography for cardiac operations.
- •
Modulate pulmonary and systemic vascular resistances as appropriate pharmacologically and by modifications in ventilation.
Postoperative
- •
Appropriate pain control (cyanotic patients have normal ventilatory response to hypercarbia and narcotics).
- •
Maintain hematocrit appropriate for arterial saturation.
- •
Maintain central venous and left atrial pressures appropriate for altered ventricular diastolic compliance or presence of beneficial atrial level shunting.
- •
Pa o 2 may not increase significantly with the application of supplemental oxygen in the face of right-to-left shunting. Similarly, neither will it decrease much with the withdrawal of oxygen (in the absence of lung pathology).
Aortic Stenosis
Valvular aortic stenosis is the most common congenital heart defect but is often not seen in that light because it typically does not cause problems until adulthood. Most aortic stenosis in adults is due to a congenitally malformed bicuspid valve that does not become problematic until late middle age or beyond, although endocarditis risk is lifelong. Once symptoms (angina, syncope, near-syncope, heart failure) develop, survival is markedly shortened. Median survival is 5 years after the development of angina, 3 years after syncope, and 2 years after heart failure. Anesthetic management of aortic stenosis does not vary whether the stenosis is congenital (most common) or acquired.
Aortopulmonary Shunts
Depending on their age, adult patients may have had one or more of several aortopulmonary shunts to palliate cyanosis during childhood. These are shown in Fig. 16.1 . Although lifesaving, these shunts had considerable shortcomings in the long term. All were inherently inefficient, because some of the oxygenated blood returning through the pulmonary veins to the left atrium and ventricle would then return to the lungs through the shunt, thus volume loading the ventricle. It was difficult to quantify the size of the earlier shunts, such as the Waterston (side-to-side ascending aorta to right pulmonary artery) and Potts (side-to-side descending aorta to left pulmonary artery). If too small, the patient was left excessively cyanotic; if too large, there was pulmonary overcirculation with the risk of developing pulmonary vascular disease. The Waterston, in fact, could on occasion stream blood flow unequally, resulting in a hyperperfused, hypertensive ipsilateral (right) pulmonary artery and a hypoperfused contralateral (left) pulmonary artery. There were also surgical issues when complete repair became possible. Takedown of Waterston shunts often required a pulmonary arterioplasty to correct deformity of the pulmonary artery at the site of the anastomosis, and the posteriorly located Potts anastomoses could not be taken down from a median sternotomy. Patients with a classic Blalock-Taussig shunt almost always lack palpable pulses on the side of the shunt, and arm length and strength can be mildly affected. Even if there is a palpable pulse (from collateral flow around the shoulder), blood pressure obtained from that arm will be artifactually low. Even after a modified Blalock-Taussig shunt (using a piece of GORE-TEX tubing instead of an end-to-side anastomosis of the subclavian and pulmonary arteries), there can be a blood pressure disparity between the arms. To ensure a valid measurement, preoperative blood pressure should be measured in both arms ( Table 16.1 ).
