Pharmacologic dilatation of the ductus arteriosus with prostaglandin E1 in infants with congenital heart disease

Prostaglandin E1 for maintaining ductal patency in neonates with ductal-dependent cardiac lesions

BACKGROUND

Prostaglandin E1 (PGE1) is used to keep the ductus arteriosus patent and can be life-saving in neonates with ductal-dependent cardiac lesions. PGE1 is used to promote mixing of pulmonary and systemic blood flow or improve pulmonary or systemic circulations, prior to balloon atrial septostomy or surgery. PGE1 therapy may cause several short-term and long-term adverse effects. The efficacy and safety of PGE1 in neonates with ductal-dependent cardiac lesions has not been systematically reviewed.

OBJECTIVES

To determine the efficacy and safety of both short-term (< 120 hours) and long-term (≥120 hours) PGE1 therapy in maintaining patency of the ductus arteriosus and decreasing mortality in ductal-dependent cardiac lesions.

SEARCH METHODS

We searched the literature in October 2017, using the search strategy recommended by Cochrane Neonatal. We searched electronic databases (CENTRAL (in the Cochrane Library), MEDLINE, CINAHL, Embase); abstracts of the Pediatric Academic Societies; websites for registered trials at www.clinicaltrials.gov and www.controlled-trials.com; and in the reference list of identified articles.

SELECTION CRITERIA

Randomized or quasi-randomized trials using PGE1 at any dose or duration to maintain ductal patency in term or late preterm (≥ 34 weeks' gestation) infants with ductal-dependent cardiac lesions and which reported effectiveness and safety in the short term or long term.

DATA COLLECTION AND ANALYSIS

We followed the standard Cochrane methods for conducting a systematic review. Two review authors (SA and MP) independently assessed the titles and abstracts of studies identified by the search strategy to determine eligibility for inclusion. We obtained the full-text version if eligibility could not be done reliably by title and abstract. We resolved any differences by discussion. We designed electronic forms for trial inclusion/exclusion, data extraction, and for requesting additional published information from authors of the original reports.

MAIN RESULTS

Our search did not identify any completed or ongoing trials that met our inclusion criteria.

AUTHORS' CONCLUSIONS

There is insufficient evidence from randomized controlled trials to determine the safety and efficacy of PGE1 in neonates with ductal-dependent cardiac lesions. Evidence from observational trials have informed clinical practice on the use of PGE, which is now considered the standard of care for ductal-dependent cardiac lesions. It is unlikely that randomized controlled studies will be performed for this indication but comparative efficacy of newer formulations of PGE1, different doses of PGE1 and studies comparing PGE with PDA stents or other measures to keep the ductus open may be ethical and necessary.

Prostaglandin Availability and Association with Outcomes for Infants with Congenital Heart Disease

Data regarding availability of prostaglandin E1 (PGE) and its impact on the stabilization, transport, critical care course, and surgical outcome of infants with ductal-dependent congenital heart disease in the current pediatric healthcare environment are unknown. We sought to determine the proportion of hospitals in Texas that stock PGE and to investigate associations between PGE availability and clinical outcomes. All birth institutions listed with the Texas Department of Health and Human Services were contacted to determine PGE availability as of 2011. Outcomes of all infants admitted to our institution from 2007 to 2012 who received PGE for ductal-dependent lesions were evaluated. PGE was stocked in 50 % (n = 139) of hospitals that performed deliveries in Texas in 2011 representing 79.1 % (303, 481) of births. Hospitals that did not stock PGE had less annual births and were located a further distance from a center that provided pediatric cardiac surgical services. Patients born at a hospital that did not stock PGE had significantly greater serum lactate and creatinine (p = 0.002) and serum lactate on admission (p < 0.001). The PGE availability was not associated with hospital length of stay, postoperative length of stay, or mortality. When stratifying in TGA and HLHS subgroups, lack of PGE availability remained associated with higher creatinine, higher lactate, lower glucose, and lower pH. PGE is not universally available in all healthcare institutions providing obstetrical services. Lack of availability of PGE at an outlying hospital was associated with increased morbidity, but was not associated with mortality or length of stay.

Efficacy of very low-dose prostaglandin E1 in duct-dependent congenital heart disease

AIM

The present study aims to define the lowest effective prostaglandin E1 dose in patients with inadequacy of pulmonary blood flow and/or intracardiac blood mixing and those with inadequate systemic blood flow.

METHODS

Patients with inadequacy of both pulmonary blood flow and/or blood mixing (Group 1) and those with inadequate systemic blood flow (Group 2) were retrospectively evaluated in two separate groups with regard to the prostaglandin E1 starting dose given in the referring facility, the lowest and the highest dose administered in our centre, treatment duration, adverse effects, and administered treatment.

RESULTS

No difference between the groups could be detected with respect to sex or birth weight (p=0.95 and 0.42, respectively). Group 1 and Group 2 were statistically similar in aspect of prostaglandin treatment duration (9.73±0.81 days versus 11.6±1.05 days, p=0.064). When compared with Group 2, the initial, maintenance and lowest efficient doses of prostaglandin E1 treatment were significantly lower and the titrated dose of prostaglandin E1 was significantly higher in Group 1 (p=0.001 for each).

CONCLUSION

Our findings indicate that the infusion of prostaglandin at a very low dose (0.003-0.005 mcg/kg/minute) is sufficient to maintain the patency of the ductus arteriosus. A higher dose of prostaglandin E1 may be necessary in patients with inadequate systemic blood flow.

Hypoplastic left heart syndrome: current considerations and expectations

In the recent era, no congenital heart defect has undergone a more dramatic change in diagnostic approach, management, and outcomes than hypoplastic left heart syndrome (HLHS). During this time, survival to the age of 5 years (including Fontan) has ranged from 50% to 69%, but current expectations are that 70% of newborns born today with HLHS may reach adulthood. Although the 3-stage treatment approach to HLHS is now well founded, there is significant variation among centers. In this white paper, we present the current state of the art in our understanding and treatment of HLHS during the stages of care: 1) pre-Stage I: fetal and neonatal assessment and management; 2) Stage I: perioperative care, interstage monitoring, and management strategies; 3) Stage II: surgeries; 4) Stage III: Fontan surgery; and 5) long-term follow-up. Issues surrounding the genetics of HLHS, developmental outcomes, and quality of life are addressed in addition to the many other considerations for caring for this group of complex patients.

To intubate or not to intubate? Transporting infants on prostaglandin E1

OBJECTIVES

The purpose of this work was to describe the pretransport and transport management of infants receiving prostaglandin E(1) infusion for congenital heart disease and to compare transport complications among unintubated and electively intubated infants.

METHODS

We conducted a retrospective chart review of 202 infants receiving prostaglandin E(1) during transport to our facility from 2000 to 2005. Prostaglandin E(1) adverse effects were described as likely or possible and transport complications as major or minor (requiring no intervention). Logistic regression was used to identify risk factors for major transport complications, and subgroup analysis compared risks among unintubated and prophylactically intubated infants.

RESULTS

Sixty-four percent of infants were intubated before transport: 34% emergently before prostaglandin E(1), 14% for prostaglandin E(1)-related adverse effects, and 11% prophylactically. Likely prostaglandin E(1) adverse effects were noted in 38% of infants, including 18% with apnea. Major complications occurred during 42% of all of the transports, including 7 (10%) of 73 unintubated infants and 14 (61%) of 23 prophylactically intubated infants. After controlling for multiple factors, elective intubation was a significant predictor of major transport complications.

CONCLUSIONS

Despite high rates of prostaglandin E(1) adverse effects, elective intubation of infants for transport significantly increased the odds of a major transport complication. The risks of prophylactic intubation before the transport of otherwise stable infants on prostaglandin E(1) must be weighed carefully against possible benefits.

Role of store-operated calcium channels and calcium sensitization in normoxic contraction of the ductus arteriosus

BACKGROUND

At birth, the increase in oxygen causes contraction of the ductus arteriosus, thus diverting blood flow to the lungs. Although this contraction is modulated by substances such as endothelin and dilator prostaglandins, normoxic contraction is an intrinsic property of ductus smooth muscle. Normoxic inhibition of potassium channels causes membrane depolarization and calcium entry through L-type calcium channels. However, the studies reported here show that after inhibition of this pathway there is still substantial normoxic contraction, indicating the involvement of additional mechanisms.

METHODS AND RESULTS

Using ductus ring experiments, calcium imaging, reverse-transcription polymerase chain reaction, Western blot, and cellular electrophysiology, we find that this depolarization-independent contraction is caused by release of calcium from the IP3-sensitive store in the sarcoplasmic reticulum, by subsequent calcium entry through store-operated channels, and by increased calcium sensitization of actin-myosin filaments, involving Rho-kinase.

CONCLUSIONS

Much of the normoxic contraction of the ductus arteriosus at birth is related to calcium entry through store-operated channels, encoded by the transient receptor potential superfamily of genes, and to increased calcium sensitization. A clearer understanding of the mechanisms involved in normoxic contraction of the ductus will permit the development of better therapy to close the patent ductus arteriosus, which constitutes approximately 10% of all congenital heart disease and is especially common in premature infants.

Prostaglandin induced cortical hyperostosis in neonates with cyanotic heart disease

OBJECTIVE

To study the side effects of prolonged prostaglandin therapy especially hyperostosis and other musculoskeletal changes.

METHODS

Case files of the neonates, with cyanotic heart disease, who had received prostaglandin infusion from early days of life, were reviewed. Patients with periosteal changes were identified. Their radiographs, serum alkaline phosphatase activity, duration and dose of prostaglandin and other side effects related to the prostaglandin were studied.

RESULTS

Ten patients developed hyperostosis, who had received PGE1 infusion for a period of 9 to 195 days. Two babies developed coarse facial features, hypertrichosis, and edema of extremities and digital swelling. Serum alkaline phosphatase activity was significantly raised in the patients, with hyperostosis. Besides long bones, ribs and scapulae, the clavicles were also involved. The involvement of clavicles has not been previously reported.

CONCLUSION

Hyperostosis is a common side effect of prolonged prostaglandin therapy. Abnormal facial features, hypertrichosis and coarse skin are additional adverse effects of long term therapy. Serum alkaline phosphatase activity can be used as a marker of the hyperostosis. In addition to other bones clavicles can also be involved. The above effects seem to be both dose and duration dependent.

Surgical management of congenital heart defects: current trends

Surgical treatment for congenital heart disease has become available over the last five decades. Palliative procedures have been designed to improve physiologic abnormalities, for example systemic artery (or venous) to pulmonary artery shunts of various types to increase the pulmonary blood flow, pulmonary artery constriction (banding) to decrease the pulmonary blood flow, and surgical or transcatheter atrial septostomy to augment intracardiac mixing. These can be performed with a low mortality. The majority of congenital heart defects can be corrected by open heart surgical techniques; some require prior palliation and others can be operated without prior palliative surgery. Recent surgical advances include early total surgical correction for tetralogy of Fallot, arterial switch procedure for transposition of the great arteries, Fontan operation and its modifications for tricuspid atresia and single ventricle, new operations for hypoplastic left heart syndrome, newer prosthetic valves, myocardial preservation and cardiac transplantation.

Congenital diaphragmatic hernia

Congenital diaphragmatic hernia continues to be a critical problem in neonatal surgery. Despite the apparent simplicity of the anatomic defect, the physiology is complex, and survival remains uncertain. Surgical success has been achieved, but we recognize that the barrier to survival is pulmonary parenchymal and vascular hypoplasia as well as the complex syndrome of persistent fetal circulation. In many ways the problem of diaphragmatic hernia is as much of an enigma to today's physician-scientist as it was to Bochdalek in the nineteenth century. The treatment of respiratory distress after repair of congenital diaphragmatic hernia has brought out the most creative and innovative efforts of pediatric surgeons in both the laboratory and the intensive care unit.

Transient neonatal tricuspid regurgitation: possible relation with premature closure of the ductus arteriosus

Normal fetal circulation requires patency of the ductus arteriosus. Prenatal ductal closure causes profound circulatory changes, such as massive tricuspid regurgitation. After delivery, the clinical picture of these severely distressed cyanotic newborns usually improves rapidly as the circulation is no longer dependent on ductal patency after onset of respiration. This case report deals with a newborn infant with severe tricuspid regurgitation and a large atrial right to left shunt who was treated with prostaglandin E1 infusion at 12 hours of age and in whom cardiac angiography revealed no evidence of either patent or functionally closed ductus arteriosus and no anatomic cardiac abnormalities at 30 hours of age. On the basis of physiologic and morphologic observations in this infant, the possible role of premature ductal narrowing or closure in the pathogenesis of transient neonatal tricuspid regurgitation is discussed. It is recommended that documentation of ductal presence or absence should become part of the diagnostic evaluation of newborns with transient tricuspid regurgitation.

Alprostadil (Prostin VR Pediatric Sterile Solution, The Upjohn Company)

Alprostadil is a naturally occurring prostaglandin used in the treatment of infants with congenital heart defects to maintain the patency of the ductus arteriosus until palliative or corrective surgery can be performed. In infants with defects restricting pulmonary blood flow (cyanotic), alprostadil improves arterial blood oxygenation. In infants with defects restricting systemic blood flow, alprostadil improves arterial blood pH, urine output, and femoral arterial pulses. Alprostadil is administered by continuous intraarterial or intravenous infusion, usually at a starting dose of 0.1 microgram/kg/min, with maintenance doses as low as 0.002 microgram/kg/min. The most common side effects include fever, apnea, flushing, bradycardia, hypotension, and seizures; although in some cases, some of these effects may be related to the infant's underlying condition. Literature reports of clinical experience with alprostadil are reviewed.

Preoperative diagnosis and management of infants with critical congenital heart disease

Operative repair with an associated low morbidity and mortality is available now for most infants with congenital cardiac defects. Precise preoperative diagnosis is an essential part of continuing attempts to lower the operative risk for these patients. In this review we cover major areas of concern in regard to preoperative diagnosis and management. Long-term follow-up studies with clinical, hemodynamic, electrophysiological, and exercise data are required to assess current diagnostic and therapeutic practices.