Bone and tissue changes following prostaglandin therapy in neonates

Impact of balloon atrial septostomy in neonates with transposition of great arteries

OBJECTIVE

To examine the impact of balloon atrial septostomy (BAS) on cardio-respiratory status, need for prostaglandin E(1) (PGE(1)) and postoperative outcomes in infants with transposition of great arteries (TGA).

STUDY DESIGN

Single-center retrospective review of consecutive neonates with dTGA.

RESULT

BAS was performed in 42 (70%) infants and resulted in a significant increase in minimum (61 to 76%) and maximum (80 to 90%) oxygen (O(2)) saturations and a drop in FiO(2). BAS was 'successful,' that is, PGE(1) was discontinued in 16 (38%) infants. Three infants died; four infants developed strokes, all of whom had undergone BAS. The duration of hospitalization, ventilation and O(2) need did not differ between infants without BAS, 'successful' BAS and unsuccessful BAS. PGE(1) duration correlated with duration of hospitalization, ventilation, O(2) need and peak respiratory severity score (P<0.03).

CONCLUSION

We speculate that limiting BAS for clinical hypoxemia and aggressive weaning of PGE(1) following BAS would improve outcomes.

Do predictors exist for a successful withdrawal of preoperative prostaglandin E(1) from neonates with d-transposition of the great arteries and intact ventricular septum?

Prostaglandin E(1) (PGE(1)) is given to neonates with d-transposition of the great arteries (d-TGA) to reduce cyanosis by reopening and maintaining the patency of the ductus arteriosus. To avoid side effects, this medication can be stopped for hemodynamically stable patients after balloon atrial septostomy (BAS). A consecutive series of neonates with d-TGA and an intact ventricular septum (IVS) presenting from 2000 through 2005 was analyzed retrospectively to search for side effects of PGE(1) and to identify predictors for a safe preoperative withdrawal. The medication was stopped for hemodynamically stable patients with transcutaneous oxygen saturations higher than 80% after BAS and reinitiated for patients with an oxygen saturation lower than 65%. Patients successfully weaned were compared with those who had failed weaning in terms of atrial septal defect (ASD) size, ductus arteriosus size, and the transcutaneous oxygen saturation. Prostaglandin E(1) was initiated for all 43 neonates with d-TGA. The median maintenance dose of PGE(1) was 0.00625 μg/kg/min (range, 0.00313-0.050 μg/kg/min) for a median duration of 6 days (range, 1-12 days). For 16 patients, PGE(1) was preoperatively withdrawn but then had to be reinitiated for 7 of the 16 patients. No predictors for a successful weaning of PGE(1) were found based on ASD size, ductus arteriosus size, or oxygen saturation. The adverse effects of PGE(1) were apnea in 10 patients and fever in 19 patients. Neither seizures nor necrotizing enterocolitis was documented. Prostaglandin E(1) was successfully withdrawn for a minority of hemodynamically stable patients with d-TGA. No predictors for a successful weaning could be identified. Because apnea and fever are common side effects, withdrawal of PGE(1) after BAS may improve patient safety and comfort. In this patient group, if PGE(1) withdrawal was not well tolerated, it could be safely reinitiated. There were no serious side effects of PGE(1.).

A novel COL1A1 mutation in infantile cortical hyperostosis (Caffey disease) expands the spectrum of collagen-related disorders

Infantile cortical hyperostosis (Caffey disease) is characterized by spontaneous episodes of subperiosteal new bone formation along 1 or more bones commencing within the first 5 months of life. A genome-wide screen for genetic linkage in a large family with an autosomal dominant form of Caffey disease (ADC) revealed a locus on chromosome 17q21 (LOD score, 6.78). Affected individuals and obligate carriers were heterozygous for a missense mutation (3040Ctwo head right arrowT) in exon 41 of the gene encoding the alpha1(I) chain of type I collagen (COL1A1), altering residue 836 (R836C) in the triple-helical domain of this chain. The same mutation was identified in affected members of 2 unrelated, smaller families with ADC, but not in 2 prenatal cases and not in more than 300 chromosomes from healthy individuals. Fibroblast cultures from an affected individual produced abnormal disulfide-bonded dimeric alpha1(I) chains. Dermal collagen fibrils of the same individual were larger, more variable in shape and size, and less densely packed than those in control samples. Individuals bearing the mutation, whether they had experienced an episode of cortical hyperostosis or not, had joint hyperlaxity, hyperextensible skin, and inguinal hernias resembling symptoms of a mild form of Ehlers-Danlos syndrome type III. These findings extend the spectrum of COL1A1-related diseases to include a hyperostotic disorder.

Cortical hyperostosis in an infant on prolonged prostaglandin infusion: case report and literature review

The common side effects associated with the use of prostaglandins in newborn infants include apnoea, hyperthermia, diarrhoea, skin flushing and oedema. Periosteal reaction or cortical thickening of the bones, also known as cortical hyperostosis, is associated with a prolonged use of prostaglandins. This is a radiological diagnosis; therefore, its occurrence is most likely underestimated. We describe an infant who developed cortical hyperostosis simulating osteomyelitis with elevated alkaline phosphatase. The radiologic changes were initially attributed to congenital syphilis. This occurred after a prolonged infusion of prostaglandin E(1) for a cyanotic congenital heart disease.

Effects of dietary fats on bone health in advanced age

Evidence is accumulating that dietary lipids play an important role in bone health. Most of the data supporting the effects of lipids on bones have been collected in young adult and/or developing animals. Based upon this work, mechanisms have been proposed to explain how lipids act to enhance or inhibit bone resorption and deposition. Little work, however, has been done in older models. Since osteoporosis primarily afflicts the elderly, such work is needed in order to determine if mechanisms relevant to the young differ in advanced age, and to develop effective interventions for this especially vulnerable segment of the population. This article reviews evidence that dietary lipids are important to bone health in older individuals, and describes possible mechanisms that may be of particular relevance to the elderly. Specifically, studies supporting the influence of dietary lipids on calcium excretion, growth hormone secretion, fatty acid metabolism, and osteoblast formation are reviewed.

The effect of prostaglandin E1 on human bone metabolism: evaluation by biochemical markers for bone turnover

Prostaglandins (PGs) have complex and multiple effects on bone metabolism. Although the osteogenic effect of PGE in humans was initially found in an infant with a congenital heart disease, there have been few reports on the effect of PGE in human in vivo. The aim of this study was to investigate the effect of PGE1 on human bone metabolism, using biochemical bone markers. A total of 18 subjects were treated with PGE1 in lipid microspheres. Six subjects were given 10 microg of lipo-PGE, intravenously daily for 14 days, and twelve subjects were given the same dose twice a week for 7 weeks. Before and after the administration of PGE1, blood and a spot urine was obtained in the morning. Bone formation markers (alkaline phosphatase, osteocalcin, procollagen I carboxy-terminal peptide) did not change. In the subjects with daily administration for 2 weeks, type I collagen pyridinolines crosslinked C-telopeptide (ICTP) increased significantly. In the subjects treated twice a week, free deoxypyridinoline (Dpd) increased significantly. When all subjects were analyzed, bone resorption markers (ICTP and Dpd) increased, but not significantly (p=0.055 for ICTP, p=0.055 for Dpd). Therefore, PGE1 at the dosage used in this study did not increase bone formation but increased bone resorption in humans.