Tag Archives: infants

Clopidogrel in Infants with Systemic-to-Pulmonary-Artery Shunts

Medications approved for adults often have additional uses in pediatric patients. Such is the case — as described by Wessel and colleagues — for clopidogrel, an agent that blocks the P2Y12 component of adenosine diphosphate (ADP) receptors on the surface of platelets. ADP receptors prevent the activation of the glycoprotein IIb/IIIa receptor complex, thereby reducing aggregation. Clopidogrel is used most commonly as a prophylactic antiplatelet therapy in adults with atherosclerotic cardiovascular disease, but is increasingly employed in the pediatric population, particularly in those with cardiac disease. Pediatric cardiovascular practitioners are using clopidogrel (along with the standard aspirin) to prevent the thrombosis of systemic-to-pulmonary-artery shunts in patients with complex cyanotic heart disease; however, the safety and efficacy of this practice have never been looked at prospectively. In the June 20 issue of The New England Journal of Medicine, investigators created a multicenter, event-driven trial to evaluate clopidogrel’s effect on infants.

A total of 906 subjects were enrolled, 467 in the clopidogrel group and 439 in the placebo group. The authors found that adding clopidogrel to conventional therapies (i.e., aspirin) did not affect mortality from any cause or shunt-thrombosis-related morbidity. Although  no statistically significant differences were detected in total subjects with adverse events,  the authors found more neurologic events in the clopidogrel group versus the placebo group. Read the full Concise Critical Appraisal.

Effect of Cardiac Function and Systemic Vascular Resistance in Premature Infants

Permissive hypercapnia is a well-accepted ventilator strategy for the management of acute respiratory distress syndrome as well as other causes of respiratory failure, such as the respiratory distress syndrome seen in premature infants. Multiple studies have demonstrated that both myocardial contractility and systemic vascular resistance (SVR) decrease with hypercapnic acidosis, the ultimate effect being that cardiac function is maintained or even augmented. The effects of hypercapnic acidosis on cardiac function in the preterm infant have not been elucidated. In a prospective observational study, published in the May issue of The Journal of Pediatrics, the authors analyzed paired blood gasses and echocardiograms from 29 hemodynamically stable preterm infants at 30 weeks gestation

Samples were taken within the first two weeks of life, either during the transitional period (days 1-3) or post-transitional period (days 4-14). In all, there were 103 paired blood gasses and echocardiograms from 21 subjects in the transitional period and 44 paired studies from 15 subjects in the post-transitional period. During the transitional period, pH and PaCO2 had no effect on any of the hemodynamic measures, including shortening fraction, stress-velocity index, or SVR. However, during the post-transitional period, the infants’ hemodynamics resembled those seen in adult patients. The results of the study demonstrated differences in the way the older infants responded to acidosis and hypercapnia. Read the full Concise Critical Appraisal.