Pediatric emergency medicine trisk 632

Please see Chapter 86 Cardiac Emergencies for emergency management of arrhythmias, shock, and acquired heart disease.. RELATED CHAPTERSSigns and Symptoms Shock: Chapter 10 Cyanosis: Chap

airway for acute obstruction is of utmost important Surgical excision or sclerotherapy is the treatment of choice depending on the type and impact of the lesion

FIGURE 96.32 Benign gingival cysts Epstein pearls (Reprinted with permission from

O’Doherty N Atlas of the Newborn Philadelphia, PA: JB Lippincott; 1979.)

FIGURE 96.33 Bohn nodule Pearly nodule on the gum of a neonate (Reprinted with

permission from Fletcher MA Physical Diagnosis in Neonatology Philadelphia, PA:

Lippincott–Raven Publishers; 1998:216.)

NEONATAL CARDIAC EMERGENCIES

This section focuses on ductal-related structural heart disease in the neonate presenting in the first few weeks of life Please see Chapter 86 Cardiac Emergencies for emergency management of arrhythmias, shock, and acquired heart disease

KEY POINTS

Congenital heart lesions can present as late as 2 to 3 weeks of age as the ductus arteriosus closes

Tachypnea may be the only sign of congestive heart failure

Femoral pulses may be palpable with aortic coarctation because of collateral vessels Instead palpate distal lower extremity pulses and obtain 4-extremity blood pressures

Prostaglandin infusion may be lifesaving even if the specific cardiac diagnosis is not known

Right-to-left shunts often are not associated with heart murmurs

RELATED CHAPTERS

Signs and Symptoms

Shock: Chapter 10

Cyanosis: Chapter 21

Heart Murmurs: Chapter 35

Respiratory Distress: Chapter 71

Septic-Appearing Infant: Chapter 73

Tachycardia: Chapter 77

Medical, Surgical, and Trauma Emergencies

Cardiac Emergencies: Chapter 86

Current Evidence

Cardiac disease presenting in the neonatal period can be acquired but is often congenital Age at presentation of CHD varies with the underlying lesion, its impact on cardiac performance, and its dependence upon the ductus arteriosus (DA) The DA, the conduit between the aorta and main pulmonary artery, allows for fetal circulatory viability in utero by allowing blood to shunt away from the collapsed lungs Postnatally, patency of the DA can preserve systemic perfusion even under conditions of abnormal cardiac anatomy In cases of impaired systemic blood flow, the right-to-left shunt of the DA mitigates the effects of even complete aortic and/or mitral atresia, allowing right ventricular output to reach the systemic circulation In cases of obstructed pulmonary blood flow, the ductus allows systemic (left ventricular) output to reach the pulmonary circulation This left-to-right shunt becomes crucial once the infant with impaired pulmonary blood flow becomes dependent on his/her own pulmonary circulation for oxygenation after delivery The DA closes functionally within the first day of life and is generally structurally closed by 3 weeks Symptoms in neonates with ductal-dependent lesions therefore typically present as early as the first few days

of life and up to 2 to 3 weeks of age

dependent cardiac lesions are divided into two categories Ductal-dependent pulmonary blood flow lesions, or right-sided obstructive lesions, include pulmonary atresia, tricuspid atresia, and critical pulmonary stenosis Ductal-dependent systemic blood flow lesions, or left-sided obstructive lesions, include hypoplastic left heart syndrome (aortic atresia), aortic coarctation, and aortic arch interruption

Goals of Treatment

For the baby with CHD and obstruction of the systemic or pulmonary blood flow, closure of the ductus can precipitate rapid clinical deterioration Emergency intervention with prostaglandins is lifesaving and therapy must be initiated even before a precise diagnosis is confirmed Once supportive care is initiated and the neonate stabilized, immediate consultation with cardiology is warranted, with timely transfer to appropriate pediatric cardiac care center

Clinical Considerations

Clinical Recognition

Newborn screening in the nursery is aimed at detecting cyanotic CHD and may not detect noncyanotic lesions Because CHD may be missed during postnatal hospitalization, ED physicians should consider CHD in the differential diagnosis

of neonates with symptoms as vague as difficulty feeding, poor weight gain, or irritability Any newborn with sudden onset or persistence of central cyanosis, severe hypoxemia, unexplained acidosis, shock, or tachypnea is considered at risk for a ductal-dependent cardiac lesion

Triage Considerations

Neonates should be triaged urgently because they can deteriorate quickly and physical findings are subtle Poor feeding may be the only presenting symptom

on history Vital signs, oxygen saturation measurement, and careful auscultation for murmurs should be performed Symmetric strong distal pedal pulses are reassuring Pulse oximetry should be measured from the preductal right hand and either postductal foot A confirmed difference in oxygen saturation between hand and foot confirms a patent ductus Blood pressure should be measured in the right arm and either leg A confirmed difference in blood pressure of more than 20 mm

Hg between the right arm and any leg suggests aortic coarctation or interrupted arch

Clinical Assessment

Physical examination should be efficient but thorough Carefully assess for gallop

or murmur A pathologic murmur is often audible in neonates with CHD Qualities of pathologic murmurs include harsh quality, murmur intensity grade 3

or higher, pansystolic duration, or abnormal S2 Always check for symmetric peripheral arterial pulses Weakened distal pulses are concerning for aortic coarctation and critical aortic stenosis but may be found with any low cardiac output state Hepatomegaly can be found in patients with left-sided obstructive