NURSING 4130: Peds Study Guide Test 2. Study Guide.

System Focused Disorders The Child with Alterations in Cardiovascular Function Ch. 48 Overview Circulatory System: - Blood enters the inferior and super vena cava to the right atrium  tricuspid valve  right ventricle  (unoxygenated blood) pulmonary arteries  lungs  (oxygenated blood) pulmonary veins  left atrium  mitral valve  left ventricle  aortic valve  aorta to the rest of the body. - Pediatric cardiac issues are very different from adult cardiac issues in that most adult issues are acquired (CHF, HTN) in children most of the issues are congenital (they are born with). If they acquire it it’s usually related to an infection (rheumatic fever). - Types o Acyanotic (ASD, VSD, PDA) – no cyanosis o Obstructive (Coarctation of the Aorta) o Cyanotic (Tetralogy of Fallot) – they are cyanotic Patent Ductus Arteriosus (PDA) P. 1302 - Ductus arteriosus connecting the aorta with the pulmonary artery stay open. - DD: Abnormal opening between the aorta (filled with high pressure rich oxygenated blood) and the pulmonary arteries (going back to the lungs to get more oxygen)  Oxygen wins, Acyanotic. Pathophysiology - A common congenital defect caused by persistent fetal circulation that accounts for 5% to 10% of all infants with congenital heart disease. When pulmonary circulation is established and systemic vascular resistance increases at birth, pressures in the aorta become greater than in the pulmonary arteries. Blood is then shunted from the aorta to the pulmonary arteries, increasing circulation to the pulmonary system. It is common problem of preterm infants who have respiratory distress syndrome or hypoxemia that work to keep the ductus arteriosus open. Clinical Manifestations - Dyspnea; tachypnea; tachycardia; full, bounding pulses; widened pulse pressure; diaphoresis (exerting too much energy); hypotension may be noted when cardiac output is low. May be asymptomatic. CHF, intercostal retractions, hepatomegaly, and poor growth when a large PDA exists. A continuous “machinery” murmur during systole and diastole, and a thrill in the pulmonic area. High risk of frequent respiratory infections and pneumonia. - DD: respiratory symptoms because you are feeding the lungs with more volume. Diagnostic Tests - The chest radiograph and ECG show left ventricular hypertrophy. The PDA can be visualized, and PDA blood flow measured on echocardiogram. Clinical Therapy - Ligation of PDA by open thoracostomy or video-assisted thoracoscopic surgery is the standard. Transcatheter closure by obstructive device is attempted in some children. IV ibuprofen or indomethacic often stimulated closure of the ductus arteriosus in preterm infants, but not if CHF is present. Prognosis - No long-term sequelae occur if treated before pulmonary vascular disease develops. If PDA is not treated, the child’s lifespan is shortened due to pulmonary HTN and pulmonary vascular obstructive disease. Atrial Septal Defect (ASD) Pg. 1302 - Abnormal opening between the two atria. Pathophysiology - The opening in the atrial septum permits left to right shunting of blood. The opening may be small, as when the foremen ovale fails to close, or large (the septum may completely be absent). 33% to 50% have an ASD in combination with other defects. - DD: its opening is in the septum dividing the right/left atrium. So if you have higher pressure on the left side of the heart and you have an opening that communicates with the right side of the heart, some of the blood is going to go right back into the lower pressure right side. Left side of the heart carries oxygenated blood and now it is going back through the opening in the septum back to the un-oxygenated right side of the heart, there is more oxygenated blood so oxygen wins the child stays acyanotic. Extra blood filling the right side leads to more volume to the lungs. Extra pulmonary circulation lead to frequent respiratory infections, children have difficulty feeding (feeding through the bottle is a form of exercise) they get tired and fatigued and they don’t tolerate their feedings. You may see JVD, edema, crackles, and fluid buildup. Clinical Manifestations - Infants and young children usually have no symptoms. Small and moderate sized ASDs may not be diagnosed until preschool years or later. Large ASDs may cause CHF, easy tiring, and poor growth. A soft systolic ejection murmur occurs in the pulmonic area with fixed, wide splitting of S2 through all phases of respiration.