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Pediatric cardiac anesthesiology, as a subspecialty, has evolved in response to the challenging and complex needs of infants and children with heart disease requiring surgical repair or palliation. Anesthetic management of this group must be all encompassing, beginning with the preoperative assessment and often continuing into the postoperative period.
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PREOPERATIVE ASSESSMENT
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Careful and complete preoperative assessment of the patient is an absolute prerequisite. In light of the congenital heart disease, the following aspects need to be addressed.
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Prenatal care and maternal conditions that may have impacted the patient.
Detailed birth history, including complications prior to or during delivery (preterm labor, premature rupture of membranes, meconium aspiration).
When and how the patient was diagnosed.
Any underlying syndrome that has anesthesia-related implications and risks (airway compromise, immunodeficiency, limb anomalies).
Postnatal history, including the presence of persistent hypoxia, cyanotic spells, respiratory distress, or decreased urine output, any of which indicate imbalanced pulmonary-to-systemic output.
Current medical therapy.
Review of previous anesthetic records and operative reports.
Evaluation of current vital signs, including preductal and postductal saturation.
Assessment of facial/mandibular structure and airway.
Auscultation of lung fields and heart sounds.
Signs of congestive heart failure, including hepatomegaly or peripheral edema.
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Laboratory Evaluation
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Complete blood count to determine the presence of polycythemia or anemia as well as preexisting thrombocytopenia.
Coagulation status, including preoperative prothrombin time (PT), activated partial thromboplastin time (PTT), and international normalizing ratio (INR).
Type and crossmatch.
Serum electrolytes, including potassium, which is often affected by diuretic medications, and blood urea nitrogen (BUN) and creatinine which can indicate perinatal injury or a prerenal state.
Liver enzymes to determine if there is liver compromise from cardiovascular disease and inadequate hepatic perfusion or metabolic disease.
Arterial blood gas (ABG) analysis with lactate is also helpful in assessing homeostasis prior to surgery. Many neonates have ductal dependent lesions and their pulmonary-to-systemic output ratio can fluctuate dramatically. Metabolic acidosis and elevated lactate levels can indicate imbalanced physiology and raise concern for inadequate tissue oxygenation due to poor systemic output or severe hypoxemia.
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Echocardiographic imaging determines cardiac anatomy and structure, heart position, chamber size and function, valvar abnormalities, shunt size and direction, and the presence of a patent ductus arteriosus.
Magnetic resonance imaging (MRI) can further delineate congenital cardiac anomalies, especially those that are difficult to visualize on echocardiography, including complex coarctation of the aorta, branch pulmonary stenosis, and vascular rings.
Cardiac catheterization provides the most accurate assessment of ventricular filling pressures and pressure gradients across areas of pathologic stenosis. It can also be necessary in the preoperative period to definitively diagnose the cardiac anatomy as well as intervene with balloon atrial septostomy, or to provide angioplasty or stenting in an attempt to optimize the patient’s physiology prior to surgery. Assessment of relative pulmonary-to-systemic ...