Neonate with Congenital Heart Disease

Successful transition of the neonatal pulmonary circulation is marked by a decrease in pulmonary vascular resistance with contributions from remodeling of the vessel wall, release of vasoactive mediators, and vessel recruitment. Nevertheless, the neonatal pulmonary circulation is particularly labile, and evidence in lambs suggests that the postnatal fall in pulmo- 

FIGURE 6 Bedside monitor recording of systemic artery pressure (SAP) and pulmonary artery pressure (PAP) in a 7-month-old child with postoperative pulmonary hypertension refractory to treatment, including hyperventilation with oxygen, anesthesia, alkalosis, nitroprus-side, prostaglandin E, and acetylcholine. Administration of 80-ppm inhaled nitric oxide produced an immediate reduction in PAP, with little effect on SAP. 

FIGURE 7 Percentage changes in hemodynamic variables from baseline values during a 15-rain administration of inhaled nitric oxide in postoperative neonates with no residual anatomic obstruction to pulmonary blood flow. There was a marked pulmonary vasodilating effect. HR, Heart rate Cl, cardiac index BP, systemic artery pressure SVR, systemic vascular resistance PAP, mean pulmonary artery pressure PVR, pulmonary vascular resistance. 

While prolonged therapy with nitric oxide may prove to be useful in the management of the postoperative neonate, care must be exercised whenever nitric oxide use is discontinued. Abrupt withdrawal of therapy, prior to resolution of the underlying disease, may precipitate a pulmonary hypertensive crisis, as occurred in one of our patients. This was promptly and effectively treated with the reintroduction of a low dose of nitric oxide (Fig. 8). Cautious weaning of the dose is advisable. 

Five of the 11 patients did not respond to inhaled nitric oxide therapy, with either a decrease in proximal pulmonary artery pressure or an increase in systemic oxygen saturation. Each of these neonates had a predisposition toward elevation of pulmonary vascular resistance postoperatively. Two of these five patients had severe pulmonary venous hypertension requiring 

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Investigators from the Department of Pediatrics in Johns Hopkins Hospital, after seeing a neonate who had marked leukocytosis temporally related to alprostadil, conducted a retrospective study of neonatal leukocytosis induced by alprostadil in 45 neonates (5). They concluded that alprostadil infusion is a predictable cause of leukocytosis in neonates with congenital heart disease. Alprostadil-induced leukocytosis was especially prominent in three patients with splenic disorders associated with the hetero-taxy syndrome. Many of the other adverse effects of alprostadil, including respiratory depression, hypotension, fever, and lethargy, were also associated with sepsis. The authors considered that it is reasonable to look for sepsis in infants receiving alprostadil, but that it is equally reasonable to withdraw empirical therapy once infection has been ruled out. Leukocytosis associated with alprostadil infusion has not been previously reported and is not listed in the alprostadil package insert. 

Alprostadil is also used to treat several aspects of cardiovascular disease. For example, it is administered intravenously to neonates with congenital heart disease to maintain the patency of the ductus arteriosus before surgery can take place. In neonates treated with alprostadil for congenital heart defects, several side effects were observed in a 3-year study examining almost 500 children. These included some cardiovascular events, and in some individuals, respiratory depression (298). Alprostadil has also been used in the treatment of peripheral vascular disease, especially Raynaud s syndrome, which is characterized by digital ischemia induced by cold and... 

The ductus arteriosus in neonates is highly sensitive to vasodilation by PGEj. Maintenance of a patent ductus may be important hemodynamically in some neonates with congenital heart disease. PGEj (alprostadil, prostin vr pediatric) is highly effective for palliative, but not definitive, therapy to maintain temporary patency until surgery can be performed. Apnea is observed in —10% of neonates so treated, particularly those who weigh <2 kg at birth. 

Wessel, D. L. (1994). Perioperative care—management of the infant and neonate with congenital heart disease. In Cardiac Surgery of the Neonate and Infant (A. R. Castaneda, R. A. Jonas, J. E. Mayer, and F.L. Hanley, eds.), pp. 65-104. Saunders, Philadelphia. 

Alprostadil is PGEi available for exogenous administration. Alprostadil is widely used in neonates with cyanotic congenital heart disease to maintain the patency of the ductus arteriosus. Reported adverse effects include fever, apnea, flushing, bradycardia, and hyperostosis. Continuous chronic infusion of alprostadil via a portable pump and neuromuscular electrical stimulation help to improve the quality of life in patients with severe chronic heart failure waiting for a donor heart, as both treatments can be performed at home. 

Sterol-A -isomerase deficiency, known as Conradi-HUnermann syndrome (CDPX2), is an X-linked dominant disorder. Clinical manifestations of this disorder include skeletal abnormalities, chondrodysplasia punctata, craniofacial anomalies, cataracts, and skin abnormalities. The 7-dehydrocholesterol reductase deficiency, known as Smith-Lemli-Opitz syndrome (SLO) is an autosomal recessive disorder occurring in about 1 in 20,000 births. Clinical manifestations of affected individuals include craniofacial abnormalities, microcephaly, congenital heart disease, malformation of the limbs, psychomotor retardation, cerebral maldevelopment, and urogenital anomalies. Measurement of 7-dehydrocholesterol in amniotic fluid during second trimester or in neonatal blood specimen has been useful in the identification of the disorder. The sterol-A " -reductase deficiency causes a developmental phenotype similar to SLO syndrome and is associated with accumulation of desmosterol. The inability of de novo fetal synthesis of cholesterol combined with its inadequate transport from the mother to the fetus appears... 

Despite the high success rates, 20% of neonates fail to respond to treatment. Factors associated with poor response inclnde sepsis, pnenmonia, PDA, congenital heart disease, pulmonary hypertension, meconium aspiration, and pulmonary hypoplasia. - Whether retreatment of RDS with surfactant after resolution of these factors is nsefnl is currently unknown. 

Pyloric stenosis may lead to obstruction of the lumen and usually presents beyond the neonatal period. However, it has been diagnosed in utero and can be seen in the neonatal period after administration of prostaglandin E to infants with ductus-dependent congenital heart disease. The stenosis is produced by central foveolar hyperplasia. On sonography, mucosal thickening often with polypoid or lobular appearance is observed, different from the muscular thickening observed in hypertrophic pyloric stenosis (Peled et al. 1992 Babyn et al. 1995) (Fig. 1.2). 

Although an association between maternal connective tissue disease and cardiac involvement in neonatal lupus was suspected as early as 1901 (M22), the association between skin disease in an infant and maternal autoimmune disease was not reported until more than 50 years later. McCuistion and Schoch (M13) described an infant with a scaly erythematosus rash whose mother had systemic lupus erythematosus. The typical association of maternal antibodies to Ro/SSA was described for congenital heart block (CHB) several decades later in 1983 (R5, S8). 

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