Persistent Doppler flow predicts lack of response to multiple courses of indomethacin in premature infants with recurrent patent ductus arteriosus

Differential determinants of patent ductus arteriosus closure for prematurity of varying birth body weight: A Retrospective Cohort Study

BACKGROUND

Patent ductus arteriosus (PDA) remains a critical issue in prematurity care. To predict the PDA closure early, we aimed to clarify the association of PDA closure with the initial postnatal 24-hour clinical characteristics and maternal and gestational histories of preterm neonates.

METHODS

A retrospective cohort study was conducted in a pediatric-neonatal-intensive-care-unit from 2008 to 2013. Data relating to birth histories, maternal histories, and clinical data from the first 24 h of life were analyzed according to three types of PDA closure-non-treated, medically-responsive, and surgically-ligated PDA and birth body weights (BBWs). Univariate analysis was performed using non-parametric analysis and Chi-square test or Fisher's exact test. Multivariate analysis was performed using multinomial logistic regression to determine the independent risk factors for the PDA closure.

RESULTS

This study involved 682 preterm infants with median gestational age of 31 (interquartile, IQR: 28-34) weeks and BBW of 1360 (IQR: 1085-1861) g. Inclusively, 16.7% of (P)DAs underwent medical and/or surgical treatment. For very low birth body weight (VLBW) neonates, surfactant use not only predicted the requirement of PDA treatment, but together with dopamine use and the larger amount of first 24-hour intravenous fluid (IVF) per kilogram of BBW, it also predicted the possibility of surgical ligation. Meanwhile, the cut-off values of the IVF amount (87 and 89.5 ml/kg/day, respectively) might predict the PDA treatment necessity and surgical ligation. For neonates with BBW ≥1500 g, placenta previa and lower BBW and systolic blood pressure (SBP) predicted the risk of treatment for PDA and its treatment response.

CONCLUSIONS

Neonatal care for PDA in prematurity should be meticulously personalized. Surfactant use, dopamine administration and the first 24-hour IVF management may be critical for PDA closure in VLBW neonates. Antepartum history of placenta previa, BBW and SBP control may be important for BBW≥1500 g.

Plasma B-type natriuretic peptide cannot predict treatment response to ibuprofen in preterm infants with patent ductus arteriosus

Plasma B-type natriuretic peptide (BNP) is a useful marker for diagnosis of hemodynamically significant PDA (hsPDA) and serial BNP measurement is also valuable for monitoring treatment response. This retrospective study was performed to evaluate whether plasma BNP level can predict treatment response to ibuprofen in preterm infants born at <30 weeks of gestation with hsPDA. Plasma BNP was measured before (baseline) and 12 to 24 h after (post-treatment) completion of the first (IBU1) and second (IBU2) course of ibuprofen. We compared the BNP levels of responders (closed or insignificant PDA) with those of non-responders (hsPDA requiring further pharmacologic or surgical closure) to each course of ibuprofen. The treatment response rates for IBU1 (n = 92) and IBU2 (n = 19) were 74% and 26%, respectively. In IBU1, non-responders had lower gestational age and birth weight than responders (both, P = 0.004), while in IBU2, non-responders had lower birth weight (P = 0.014) and platelet counts (P = 0.005) than responders; however, baseline BNP levels did not differ significantly between responders and non-responders in either IBU1 (median 1,434 vs. 1,750 pg/mL) or IBU2 (415 vs. 596 pg/mL). Post-treatment BNP was a useful marker for monitoring treatment efficacy of IBU1 and IBU2 for hsPDA with a cut-off value of 331 pg/mL (P < 0.001) and 423 pg/mL(P < 0.010), respectively. We did not identify a cut-off baseline BNP level that could predict treatment response to ibuprofen in preterm infants with hsPDA.

Base excess and hematocrit predict response to indomethacin in very low birth weight infants with patent ductus arteriosus

Background

The treatment of patent ductus arteriosus (PDA) in very low birth weight (VLBW) infants remains a challenge. The ability to predict which infants will respond to indomethacin could spare some from the risks of unnecessary medications. Our objective was to determine if indicators of acid-base homeostasis could predict response to indomethacin treatment for ductal closure, and thus help guide treatment decisions.

Methods

We performed a retrospective analysis of medical records of VLBW (< 1500 g) neonates with hemodynamically significant PDA born at our institution between January 2009 and December 2012; all infants included in the study were treated with indomethacin for ductal closure within the first 2 weeks of life. We extracted data for a number of clinical variables including gestational age, birth weight, blood chemistries, surfactant use, hematocrit, and blood gas parameters. Our primary outcome measure was successful closure of PDA following the first round of indomethacin. Using variables that were significant on initial testing, we created multivariable regression models to determine the independent association of selected variables with indomethacin response.

Results

Of the 91 infants included in the study, 62 (68%) responded to the first course of indomethacin with successful ductal closure. Multivariable regression modeling revealed that both base excess and hematocrit were independently associated with indomethacin response; odds of PDA closure increased with increasing base excess (OR [odds ratio]: 1.81; 95% confidence interval [CI]: 1.36–2.60) and increasing hematocrit (OR: 1.21; 95% CI: 1.01–1.45). The optimal cutoff value for base excess was − 4.56, with a sensitivity of 96.8% (95% CI: 89–100) and specificity of 79.3% (95% CI: 60–92); optimal cutoff value for hematocrit was 40, with 69.4% sensitivity (95% CI: 56–80) and 65.5% specificity (95% CI: 46–82).

Conclusions

Base excess and hematocrit may be independent predictors of indomethacin response in VLBW infants with PDA. Low-cost and readily accessible, acid-base indicators such as base excess could help guide treatment decisions.

Electronic supplementary material

The online version of this article (10.1186/s13052-019-0706-y) contains supplementary material, which is available to authorized users.

Reopening of the ductus arteriosus in preterm infants; Clinical aspects and subsequent consequences

OBJECTIVE

Patent ductus arteriosus is a common problem frequently encountered in preterm infants. We aimed to study the risk factors associated with reopening of patent ductus arteriosus and their short term outcomes in preterm infants.

METHODS

A total of 162 preterm infants born between November 2013 and December 2015 with gestaional age less than 32 weeks and treated for hemodynamically significant patent ductus arteriosus are included in our study.

RESULTS

113(69.8%) showed permanent closure and 49(30.2%) infants revealed symptoms of reopening after effective closure of patent ductus arteriosus. Low birth weight and small gestational age were more common in reopening group. Multivariete analysis showed that sepsis and multiple courses of drug treatment were independent factors affecting reopening of hemodynamically significant patent ductus arteriosus (OR: 3.01, 95% CI 1.48-6.13, p = 0.002) and (OR: 2.67, 95% CI 1.23-5.82, p = 0.013) respectively. Reopened group had a remarkable higher rate of developing necrotising nnterocolitis, bronchopulmonary dysplasia and retinopathy of prematurity than the closed group. (16.3% vs 4.4%, p = 0.01, 55.1% vs 28.3%, p = 0.001 and 55.1% vs 23.0%, p = 0.0001 respectively).

CONCLUSION

Late neonatal sepsis and the need of multiple drug courses to close patent ductus arteriosus are risk factors affecting the reopening of patent ductus arteriosus in preterm infants.

Efficacy of pharmacologic closure of patent ductus arteriosus in small-for-gestational-age extremely preterm infants

BACKGROUND

Optimal management of the patent ductus arteriosus (PDA) in preterm infants remains controversial. Therefore, studies identifying infants who are most likely to benefit from PDA treatment are needed.

AIM

We sought to examine if significant intrauterine growth restriction, defined by birth weight z-score, reduces the efficacy of PDA closure with indomethacin or ibuprofen and thereby increases the need for surgical closure of PDA after pharmacologic treatment.

STUDY DESIGN, SUBJECTS, AND OUTCOME MEASURES

We studied infants 23-28weeks' gestation born 2006-2013 at NICHD Neonatal Research Network centers. We examined the responses to PDA treatment with indomethacin and/or ibuprofen and whether the PDA was subsequently closed surgically. Logistic regression generated adjusted odds ratios (ORs) for the associations between the z-score groups (<-2, -2 to -0.5, and >-0.5) and PDA surgery following pharmacologic treatment.

RESULTS

5606 infants were diagnosed with PDA; 3587 (64.0%) received indomethacin or ibuprofen or both, and 909 (25.3%) underwent PDA surgery. Mothers of infants with PDA non-closure were less likely to have hypertension (19% vs. 28%). Infants with non-closure were more likely to be female (53% vs. 49%), have lower gestational age and birth weight and to develop sepsis (42% vs. 31%). Compared to infants with z-score>-0.5, PDA surgery was increased among infants with z-score -2 to -0.5 (OR=1.23; 95% CI 1.02-1.47) but not among infants with z-score<-2.

CONCLUSION

Infants with birth weight z-score -2 to -0.5 are more likely than normally grown infants to require PDA surgery following pharmacologic treatment.

Factors associated with non-response to second course indomethacin for PDA treatment in preterm neonates

BACKGROUND

Failure of first course of indomethacin (FCI) for patent ductus arteriosus (PDA) treatment in preterm neonates often prompts clinicians to consider a second course (SCI).

OBJECTIVE

To identify factors including baseline characteristics and response to FCI that are associated with non-response to SCI for PDA treatment in preterm neonates.

METHODS

In this retrospective observational study, neonates ≤32 weeks admitted to a tertiary NICU over 5 years who received two indomethacin courses for PDA treatment were reviewed. Only neonates with echocardiograms (ECHO) immediately before and after receipt of each indomethacin course were included. Primary outcome was non-response to SCI. Baseline characteristics and response to FCI were compared between responders and non-responders of SCI.

RESULTS

Of the 98 neonates enrolled, 47 (48%) had non-response to SCI. Of them, 27 patients (57%) had prior non-response to FCI, while of the 51 neonates who responded to SCI, 24 neonates (47%) had prior non-response to FCI. The adjusted risk of non-response to SCI in patients who had non-response to FCI was 37% higher (relative risk = 1.37, 95%CI: 0.87-1.80; p = .07) compared to those who had response to FCI. Multivariable analysis showed that increasing gestational age (AOR: 1.6, 95%CI: 1.1-2.3, p = .03) was associated with a higher odds of non-response to SCI while the odds of non-response to SCI increased by 90% in patients with non-response to FCI (AOR: 1.9, 95%CI: 0.8-4.5; p = .15) compared to those with success of FCI, although no statistical significance was observed.

CONCLUSIONS

Advanced gestational age was the predictor of non-response to SCI in preterm neonates.

Repeated Courses of Oral Ibuprofen in Premature Infants with Patent Ductus Arteriosus: Efficacy and Safety

BACKGROUND

There are limited data about the results of repeated oral ibuprofen (OIBU) treatment. This study aimed to describe patent ductus arteriosus (PDA) closure rates and adverse events after repeated courses of OIBU in premature infants with PDA.

METHODS

Preterm infants with hemodynamically significant (hs)PDA were enrolled in the study. If the first course of OIBU treatment failed, a second and, if required, third course was administered.

RESULTS

A total of 100 patients received OIBU. In six patients, treatment could not be completed due to death (n=3) and side effects (n=3). In three patients, adverse effects related to OIBU (thrombocytopenia and impairment of renal function) developed during the first course. During the second and third courses, no new adverse event occurred. After all courses, the PDA closure rate was determined as 88%. The rate was 71% after the first course, 40% after the second course, and 35% after the third course. Although the second course resulted in a significant increase in the closure rate (p<0.05), the rate did not increase significantly with the third course (p>0.05). The mean postnatal age at the start of the first dose of OIBU was not significantly different among the responders and non-responders to the first course (p>0.05). Clinical characteristics did not affect the closure rate significantly. The number of courses did not have a significant effect on death, when gestational age and birth weight were used as covariates [p=0.867, Exp(B)=0.901, 95% confidence interval=0.264-3.1].

CONCLUSION

A second course of OIBU seems effective and safe for use in preterm infants with hsPDA. Although a third course of OIBU results in PDA closure in some additional patients, the difference is not significant. Thus, surgical ligation should be considered after the second course, especially in patients with signs of severe heart failure.

Intravenous paracetamol for PDA closure in the preterm: a single-center experience

Increasing recent evidence favors paracetamol use for patent ductus arteriosus (PDA) closure in preterms. Our study aims were (1) to assess efficacy and safety of intravenous (i.v.) paracetamol for PDA closure in a 23-32-week preterm population, as "first-line" (when traditional ibuprofen treatment was contraindicated) or "rescue" treatment (after ibuprofen failed), and (2) to identify predictors of PDA closure. The cumulative efficacy of consecutive cycles of i.v. paracetamol on PDA closure was confirmed after both "first-line" and "rescue" treatment, the overall PDA closure rates being, respectively, 56.7 and 61.1 % (p = 0.7624) after two cycles and 63.3 and 77.8 % (p = 0.2959) after three cycles. No toxicity was apparent after either "first-line" or "rescue" i.v. paracetamol treatment. On multivariate analysis, gestational age (GA) emerged as an independent predictor of PDA closure in the "first-line" i.v. paracetamol treatment group, while clinical risk index for babies (CRIB) score (a patient risk index based on birth weight, GA at birth, sex, patient's temperature on admission, and maximum base excess in first 12 h of life) was an independent predictor of PDA closure failure in the "rescue" group.

CONCLUSION

I.V. paracetamol proved effective in our study population. Randomized control trials (RCTs) are warranted to further investigate the efficacy and safety of i.v. paracetamol for PDA closure in preterms.

WHAT IS KNOWN

• Oral paracetamol has been judged as effective as oral ibuprofen for PDA closure in the preterm. • To date, only a handful of non-randomized studies exist to support the effectiveness of i.v. paracetamol in PDA closure. What is New: • Our observations confirm the clinical efficacy of i.v. paracetamol for PDA closure in a very low birth weight (VLBW)/extremely low birth weight (ELBW) preterm population. • Gestational age and CRIB score emerge as independent predictors of PDA closure.

Preterm patent ductus arteriosus: A continuing conundrum for the neonatologist?

How to manage the preterm patent ductus arteriosus (PDA) remains a conundrum. On the one hand, physiology and statistical association with adverse outcomes suggest that it is pathological. On the other hand, clinical trials of treatment strategies have failed to show any long-term benefit. Ultrasound studies of PDA have suggested that the haemodynamic impact may be much earlier after birth than previously thought (in the first hours); however, we still do not know when to treat PDA. Studies that have tested symptomatic or pre-symptomatic treatment are mainly historical and have not tested the effect of no treatment. Prophylactic treatment is the best-studied regimen but improvements in some short-term outcomes do not translate to any difference in longer-term outcomes. Neonatologists have been reluctant to engage in trials that test treatment against almost never treating. Observations of very early postnatal haemodynamic significance suggest that targeting treatment on the basis of the early postnatal constrictive response of the duct may optimize benefits. A pilot trial of this strategy showed reduction in the incidence of pulmonary haemorrhage but more trials of this strategy are needed.

Indomethacin vs ibuprofen: comparison of efficacy in the setting of conservative therapeutic approach

Indomethacin has been the mainstay for medical closure of patent ductus arteriosus. With its discontinuation, many units shifted to the use ibuprofen. We compared the therapeutic efficacy (successful closure, a priori defined as complete closure or >50% reduction in size) and the impact of the two drugs on neonatal morbidities. Two time epochs were analysed (IV indomethacin, January 2008 to November 2010, and IV ibuprofen lysine, November 2010 to September 2013). Demographic, clinical and echocardiographic data was compared. A total of 101 infants formed the study population, 58 (57.4%, indomethacin epoch) and 43 (42.6%, ibuprofen epoch). The gestational age, birth weight and postnatal age at initial treatment respectively were comparable [26 ± 1.8 vs 26.5 ± 1.9 weeks, 806 ± 183 vs 862 ± 234 g and median 12 (6, 17) vs 11 days (8, 18)]. Successful closure was significantly higher in the indomethacin group [26 (45%) vs 6 (14%), p < 0.01]. The incidence of bronchopulmonary dysplasia (BPD) and discharge in oxygen was comparable. Four infants (all in the ibuprofen group) developed pulmonary hypertension; one required pulmonary vasodilator therapy. Posttreatment serum creatinine was significantly lower in the ibuprofen group. Mortality was higher during the indomethacin epoch. On univariate analysis, the choice of the drug and higher gestational age were associated with successful closure.

CONCLUSION

Indomethacin was more efficacious for ductal closure although did not impact outcomes. Use of staging schema may help understand 'need to treat' and refine therapy.

Patent ductus arteriosus in preterm infants: do we have the right answers?

Patent ductus arteriosus (PDA) is a common clinical condition in preterm infants. Preterm newborns with PDA are at greater risk for several morbidities, including higher rates of bronchopulmonary dysplasia (BPD), decreased perfusion of vital organs, and mortality. Therefore, cyclooxygenase (COX) inhibitors and surgical interventions for ligation of PDA are widely used. However, these interventions were reported to be associated with side effects. In the absence of clear restricted rules for application of these interventions, different strategies are adopted by neonatologists. Three different approaches have been investigated including prophylactic treatment shortly after birth irrespective of the state of PDA, presymptomatic treatment using echocardiography at variable postnatal ages to select infants for treatment prior to the duct becoming clinically significant, and symptomatic treatment once PDA becomes clinically apparent or hemodynamically significant. Future appropriately designed randomized controlled trials (RCTs) to refine selection of patients for medical and surgical treatments should be conducted. Waiting for new evidence, it seems wise to employ available clinical and echocardiographic parameters of a hemodynamically significant (HS) PDA to select patients who are candidates for medical treatment. Surgical ligation of PDA could be used as a back-up tool for those patients who failed medical treatment and continued to have hemodynamic compromise.

Neurodevelopmental outcomes following two different treatment approaches (early ligation and selective ligation) for patent ductus arteriosus

OBJECTIVE

To examine whether a change in the approach to managing persistent patent ductus arteriosus (PDA) from early ligation to selective ligation is associated with an increased risk of abnormal neurodevelopmental outcomes.

STUDY DESIGN

In 2005, we changed our PDA treatment protocol for infants born at ≤27 6/7 weeks' gestation from an early ligation approach, with prompt PDA ligation if the ductus failed to close after indomethacin therapy (period 1: January 1999 to December 2004), to a selective ligation approach, with PDA ligation performed only if specific criteria were met (period 2: January 2005 to May 2009). All infants in both periods received prophylactic indomethacin. Multivariate analysis was used to compare the odds of a composite abnormal neurodevelopmental outcome (Bayley Mental Developmental Index or Cognitive Score <70, cerebral palsy, blindness, and/or deafness) associated with each treatment approach at age 18-36 months (n = 224).

RESULTS

During period 1, 23% of the infants in follow-up failed indomethacin treatment, and all underwent surgical ligation. During period 2, 30% of infants failed indomethacin, and 66% underwent ligation after meeting prespecified criteria. Infants treated with the selective ligation strategy demonstrated fewer abnormal outcomes than those treated with the early ligation approach (OR, 0.07; P = .046). Infants who underwent ligation before 10 days of age had an increased incidence of abnormal neurodevelopmental outcome. The significant difference in outcomes between the 2 PDA treatment strategies could be accounted for in part by the earlier age of ligation during period 1.

CONCLUSION

A selective ligation approach for PDAs that fail to close with indomethacin therapy is not associated with worse neurodevelopmental outcomes at age 18-36 months.

Repeated courses of ibuprofen are effective in closure of a patent ductus arteriosus

Patent ductus arteriosus (PDA) is a frequent complication in preterm infants. Ibuprofen and indomethacin (both COX inhibitors) are used for pharmacological closure of PDA. In most centers, a failed second course of COX inhibitors is followed by surgical closure. Our aim was to estimate the closure rate of clinically significant PDA after second and third courses of ibuprofen and record possible side effects. A study population, consisting of 164 preterm infants (<32 weeks' gestational age) with PDA admitted at our tertiary care center between November 2005 and September 2011, was retrospectively analyzed. Primary outcome was the closure rate after repeated courses of ibuprofen. The closure rate was similar after the first (109/164), second (24/43), and third (6/11) course of ibuprofen (X(2) = 2.1, p = 0.350). Late start of the first course of ibuprofen was a predictive factor for increased need of a second course (X(2) = 4.4, p = 0.036). No additional side effects of multiple courses of ibuprofen were detected. In conclusion, repeated courses of ibuprofen are an effective and safe alternative for surgical closure and should be considered after failure of the first course of ibuprofen.

Preterm patent ductus arteriosus: should we treat it?

Debate about the importance of the preterm patent ductus arteriosus (PDA) remains unresolved. Ultrasound studies of PDA have suggested that the haemodynamic impact may be much earlier after birth than previously thought, but we still do not know when to treat a PDA. Studies that have tested symptomatic or pre-symptomatic treatment are mainly historical and have not tested the effect of no treatment. Prophylactic treatment is the best studied regimen, but improvements in some short-term outcomes do not translate to any difference in longer term outcomes. Neonatologists have been reluctant to engage in trials that test treatment against not treating at all or very rarely. Targeting treatment on the basis of the early post-natal constrictive response of the duct is currently being tested as a possible strategy.

Patent ductus arteriosus in premature neonates

Persistent patency of the ductus arteriosus is a major cause of morbidity and mortality in premature infants. In infants born prior to 28 weeks of gestation, a haemodynamically significant patent ductus arteriosus (PDA) can cause cardiovascular instability, exacerbate respiratory distress syndrome, prolong the need for assisted ventilation and increase the risk of bronchopulmonary dysplasia, intraventricular haemorrhage, renal dysfunction, cerebral palsy and mortality. We review the pathophysiology, clinical features and assessment of haemodynamic significance, and provide a rigorous appraisal of the quality of evidence to support current medical and surgical management of PDA of prematurity. Cyclo-oxygenase inhibitors such as indomethacin and ibuprofen remain the mainstay of medical therapy for PDA, and can be used both for prophylaxis as well as for rescue therapy to achieve PDA closure. Surgical ligation is also effective and is used in infants who do not respond to medical management. Although both medical and surgical treatment have proven efficacy in closing the ductus, both modalities are associated with significant adverse effects. Because the ductus does undergo spontaneous closure in some premature infants, improved and early identification of infants most likely to develop a symptomatic PDA could help in directing treatment to the at-risk infants and allow others to receive expectant management.

Clinical aspects of very-low-birthweight infants showing reopening of ductus arteriosus

BACKGROUND

Indomethacin is used to treat the hemodynamically significant patent ductus arteriosus in premature infants. Some infants show ductus arteriosus reopening after effective constriction by the drug. The purpose of this study was to examine the clinical characteristics of such infants.

METHODS

We studied 57 very-low-birthweight infants with effective constriction of patent ductus arteriosus by the initial course of indomethacin. They were classified into the reopened group if they developed hemodynamically significant patent ductus arteriosus again or into the closed group if they showed complete closure. Clinical characteristics were compared between the two groups.

RESULTS

Ductus arteriosus reopening was shown in 15 (26%) of the 57 infants. These 15 infants had successful clinical ductal closure after a subsequent course of indomethacin or oral mefenamic acid treatment or surgical ligation without any severe complications. Infants in the reopened group showed significantly higher rates of developing chronic lung disease at 36 weeks of gestation than those in the closed group (53% vs 18%; P= 0.009). Furthermore, multivariate logistic regression analysis revealed ductus arteriosus reopening was the only independent risk factor for developing chronic lung disease at 36 postconceptional weeks in this population (adjusted odds ratio, 6.1; 95% confidence interval, 1.4-31.2; P= 0.02).

CONCLUSIONS

Incomplete closure of the ductus arteriosus is associated with recurrence of a clinically significant patent ductus arteriosus and reopening of the ductus after initial closure with indomethacin is associated with chronic lung disease.

Interatrial defect and patent ductus arteriosus

We greatly appreciated the letter to the Editor by Rana Olgunturk and Serdar Kula. We can say that his interpretation coincides with our interpretation and with the knowledge about patent ductus arteriosus (PDA) and secundum atrial septal defects. Although functional closure of PDA usually occurs in the first few hours of life in healthy infants born at term (about 15 h of life in healthy infants born at term), true anatomic closure, in which the ductus loses the ability to reopen, may take several weeks. Persistent, patency for up to 10 days after birth is encountered in premature infants. The male Italian newborn infant of the cited case report was referred at the age of 2 days to the Cardiology Unit for a cardiovascular check-up (in the text: "in a 3-day-old newborn infant" must be comprehended as "in a 2-day-old newborn infant") and was mature. Interatrial septal shunts in newborns are frequently encountered. Since there are no definitive diagnostic criteria for both patent foramen ovale and secundum atrial septal defects, it is difficult to differentiate these two lesions by echocardiography, particularly in the early newborn period. Some authors, called these two lesions as "interatrial septal openings". The diagnosis, in the case report cited, was made not only on the basis of the first observation but also on the basis of the persistence of abnormalities during the long-term follow-up and therefore the infant was referred to a pediatric heart surgical unit were the abnormalities were confirmed.

Early surgical ligation versus a conservative approach for management of patent ductus arteriosus that fails to close after indomethacin treatment

OBJECTIVE

To examine whether a more conservative approach to treating patent ductus arteriosus (PDA) is associated with an increase or decrease in morbidity compared with an approach involving early PDA ligation.

STUDY DESIGN

In January 2005, we changed our approach to infants born at age

RESULTS

The 2 periods had similar rates of perinatal/neonatal risk factors and indomethacin failure (24%), as well as ventilator management and feeding advance protocols. The conservative approach (period 2) was associated with decreased rates of duct ligation (72% vs 100%; P<.05). Even though infants subjected to this approach were exposed to larger PDA shunts for longer durations, the rates of bronchopulmonary dysplasia, sepsis, retinopathy of prematurity, neurologic injury, and death were similar to those in period 1. The overall rate of necrotizing enterocolitis was significantly lower in period 2 compared with period 1.

CONCLUSIONS

These findings support the need for new controlled, randomized trials to reexamine the benefits and risks of different approaches to PDA treatment.

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Key Words

• surgery
• ductus ligation
• indomethacin
• patent ductus arteriosus

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MESH Headings

• Ductus Arteriosus, Patent/drug therapy
• Ductus Arteriosus, Patent/surgery
• Female
• Humans
• Indomethacin/therapeutic use
• Infant, Newborn
• Ligation
• Male
• Prospective Studies
• Time Factors
• Treatment Failure

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Grants

• R01 HL046691 NHLBI NIH HHS
• R01 HL046691-16 NHLBI NIH HHS
• UL1 RR024131 NCRR NIH HHS
• HL46691 NHLBI NIH HHS

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Affiliation(s)

Nami Jhaveri Department of Pediatrics, University of California, San Francisco, CA 94143-0544, USA
Anita Moon-Grady
Ronald I Clyman

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Echocardiography predicts closure of patent ductus arteriosus in response to ibuprofen in infants less than 28 week gestational age

BACKGROUND

Patent ductus arteriosus (PDA) is a frequent problem in preterm infants, and its incidence is inversely correlated with gestational age. The efficacy of medical treatment decreases with decreasing gestational age (GA), and failure rates as well as ductus ligation rates of 40% have been reported in <28 week GA newborns. The aim of this study was to determine whether echocardiographic parameters can predict response to ibuprofen treatment of PDA.

STUDY DESIGN

In a longitudinal study, 29 infants born <28 week GA were screened for a significant PDA (left atrial to aortic root ratio>1.4, anterior cerebral artery resistance index>0.8, and oxygen requirement>35%) at 24-72 h of life and, if a PDA was found, treated with 10-5-5mg/kg ibuprofen intravenously every 24h. Ductal parameters were monitored by serial echocardiography. Infant neurodevelopmental outcomes were assessed at 24 month corrected age.

RESULTS

All 15 infants with significant PDA responded to the ibuprofen loading dose indicated by reduced PDA diameters or increased PDA maximum flow velocities (PDA V(max)), and 7 patients showed an ongoing response resulting in a closed PDA after the 1st cycle (47%). Of the 8 non-responders, 7 received a 2nd cycle with 2 further responders (29%). All non-responders to the 2nd course had a PDA V(max)<or=180 cm/s and increasing ductal diameters after the 3rd ibuprofen dose of the 1st course.

CONCLUSION

Maximum flow velocity and diameter of the PDA at the end of the 1st cycle discriminate between responders and non-responders to further ibuprofen treatment.

Inadvertent relaxation of the ductus arteriosus by pharmacologic agents that are commonly used in the neonatal period

Premature birth and disruption of the normal maturation process leave the immature ductus arteriosus unable to respond to postnatal cues for closure. Strategies that advocate conservative management of the patent ductus arteriosus (PDA) in premature infants are dependent on identification of the symptomatic PDA and understanding the risk factors that predispose to PDA. Exposure of premature infants to unintended vasodilatory stimuli may be one of the risk factors for PDA that is under recognized. In this article, we summarize the clinical factors that are associated with PDA and review commonly used neonatal drugs for their vasodilatory properties. Data demonstrating relaxation of the ductus arteriosus by gentamicin and other aminoglycoside antibiotics, by cimetidine and other H2 receptor antagonists, and by heparin are provided as examples of neonatal therapies that have unanticipated effects that may promote PDA.

Management of patent ductus arteriosus in term or near-term neonates with respiratory distress

BACKGROUND

Respiratory distress and patent ductus arteriosus (PDA) in neonates are mutually perpetuating. Contrary to the situation in premature infants, the recognition, clinical relevance and optimal management of PDA in full-term neonates are unclear. The present study aimed to identify PDA as a possible cause of respiratory distress in term and near-term neonates, and to examine the clinical responsiveness of PDA to different treatment modalities in mature-gestational-age neonates.

METHODS

Patients with gestational ages of over 34 weeks were included in this retrospective chart review; they had PDA as the sole recognizable cause of respiratory distress and were free of all other diseases. Clinical responsiveness to different regimens, including conservative treatment, drug therapy with preload reduction and inotropic agent with or without the addition of indomethacin, and surgical intervention were analyzed.

RESULTS

Forty-four neonates qualified for this study. Six received no treatment and their cardiorespiratory symptoms resolved within 1 week (regimen A). Symptoms in 11 neonates were relieved after use of diuretic and inotropic agents (regimen B). Twelve neonates became asymptomatic without further intervention after indomethacin treatment in addition to preload reduction and inotropes (regimen C). A total of 15 of the 44 infants underwent PDA ligation (regimen D) due to persistent heart failure following regimens B or C, but had speedy resolution of respiratory symptoms following surgery. There were significant differences in birth body weight and hemodynamic variation based on left atrium to aortic root dimensional ratio between the treatment (regimens B, C and D) and non-treatment (regimen A) groups (p < 0.05).

CONCLUSION

PDA plays an important role in prolonging respiratory distress in term or near-term neonates. Although most infants respond to noninvasive medical treatment, surgical ligation during the neonatal period is warranted in certain mature infants. Surgical treatment should be considered in patients with smaller birth body weights and those with increased left atrium to aortic root dimensional ratios.

Patent ductus arteriosus of the preterm infant

A persistently patent ductus arteriosus (PDA) in preterm infants can have significant clinical consequences, particularly during the recovery period from respiratory distress syndrome. With improvement of ventilation and oxygenation, the pulmonary vascular resistance decreases early and rapidly, especially in very immature infants with extremely low birth weight (<1000 g). Subsequently, the left-to-right shunt through the ductus arteriosus (DA) is augmented, thereby increasing pulmonary blood flow, which leads to pulmonary edema and overall worsening of cardiopulmonary status. Prolonged ventilation, with the potential risks of volutrauma, barotrauma, and hyperoxygenation, is strongly associated with the development and severity of bronchopulmonary dysplasia/chronic lung disease. Substantial left-to-right shunting through the ductus may also increase the risk of intraventricular hemorrhage, necrotizing enterocolitis, and death. Postnatal ductal closure is regulated by exposure to oxygen and vasodilators; the ensuing vascular responses, mediated by potassium channels, voltage-gated calcium channels, mitochondrial-derived reactive oxygen species, and endothelin 1, depend on gestational age. Platelets are recruited to the luminal aspect of the DA during closure and probably promote thrombotic sealing of the constricted DA. Currently, it is unclear whether and when a conservative, pharmacologic, or surgical approach for PDA closure may be advantageous. Furthermore, it is unknown if prophylactic and/or symptomatic PDA therapy will cause substantive improvements in outcome. In this article we review the mechanisms underlying DA closure, risk factors and comorbidities of significant DA shunting, and current clinical evidence and areas of uncertainty in the diagnosis and treatment of PDA of the preterm infant.

Comparison of intravenous and enteral indomethacin administration for closure of patent ductus arteriosus in extremely-low-birth-weight infants

BACKGROUND

The objective of this retrospective cohort study was to compare the patent ductus arteriosus (PDA) closure rate with different routes (intravenous and enteral) of indomethacin treatment and neonatal outcomes.

METHODS

Infants with a birthweight < 1,000 g born between July 1997 and June 2007 at Taipei Veterans General Hospital and who received indomethacin treatment for PDA were included in the study. Outcome measures were ductal closure rate and neonatal outcomes.

RESULTS

Of 41 extremely-low-birth-weight infants with PDA, 3 infants had spontaneous closure and 3 died before treatment. Of the remaining 35 infants, 13 received enteral ethanol solution of indomethacin and 22 received the intravenous (IV) form. The total closure rates of the IV and enteral groups were 81.8% and 76.9%, respectively. There were no significant differences in the incidence of impaired renal function, necrotizing enterocolitis, chronic lung disease or severe retinopathy of prematurity between the 2 groups.

CONCLUSION

Our results suggest that ethanol-based indomethacin is an effective alternative to IV indomethacin for the pharmacological closure of PDA in extremely-low-birth-weight infants.

A second course of ibuprofen is effective in the closure of a clinically significant PDA in ELBW infants

OBJECTIVES

There are few published data on the efficacy of ibuprofen in the most immature infants and no data on repeated courses. Our objectives were to describe PDA closure rates in a population of infants <1000 g birth weight after repeated courses of ibuprofen, to examine the effect of gestation, and to document plasma markers of renal function and platelet counts.

METHODS

This was a single center observational study. We collected data on infants weighing <1000 g at birth who were treated with ibuprofen for a clinically significant PDA. A successful outcome was defined as resolution of clinical symptoms such that no additional treatment was required. Serum biochemistry and hematology data were analyzed and compared with controls.

RESULTS

We identified 160 infants with a mean +/- SD birth weight of 757 +/- 127 g and gestation of 25.6 +/- 1.4 weeks. Seventy infants closed their PDA after a single course of ibuprofen (45%) and 32/80 (40%) following a second. Infants of <26 weeks' gestation (n = 83) were less likely to respond after both the first (27.7% vs 63.6%; P < .001) and second (30.9% vs 60.0%; P = .026) courses. The postnatal decrease in plasma creatinine was delayed by ibuprofen treatment, while platelet counts and other plasma markers were unaffected.

CONCLUSIONS

In our study population, PDA closure was gestation dependant, with a cumulative closure rate of 65%. A similar proportion of infants closed their PDA following the first and second courses regardless of gestation. These data suggest that a second course of ibuprofen may be effective in closing a PDA in even the most preterm infant.

Patent ductus arteriosus therapy: impact on neonatal and 18-month outcome

OBJECTIVE

The purpose of this work was to evaluate therapy for patent ductus arteriosus as a risk factor for death or neurodevelopmental impairment at 18 to 22 months, bronchopulmonary dysplasia, or necrotizing enterocolitis in extremely low birth weight infants.

METHODS

We studied infants in the National Institute of Child Health and Human Development Neonatal Research Network Generic Data Base born between 2000 and 2004 at 23 to 28 weeks' gestation and at <1000-g birth weight with patent ductus arteriosus. Patent ductus arteriosus therapy was evaluated as a risk factor for outcomes in bivariable and multivariable analyses.

RESULTS

Treatment for subjects with patent ductus arteriosus (n = 2838) included 403 receiving supportive treatment only, 1525 treated with indomethacin only, 775 with indomethacin followed by secondary surgical closure, and 135 treated with primary surgery. Patients who received supportive therapy for patent ductus arteriosus did not differ from subjects treated with indomethacin only for any of the outcomes of interest. Compared with indomethacin treatment only, patients undergoing primary or secondary surgery were smaller and more premature. When compared with indomethacin alone, primary surgery was associated with increased adjusted odds for neurodevelopmental impairment and bronchopulmonary dysplasia in multivariable logistic regression. Secondary surgical closure was associated with increased odds for neurodevelopmental impairment and increased adjusted odds for bronchopulmonary dysplasia but decreased adjusted odds for death. Risk of necrotizing enterocolitis did not differ among treatments. Indomethacin prophylaxis did not significantly modify these results.

CONCLUSIONS

Our results suggest that infants treated with primary or secondary surgery for patent ductus arteriosus may be at increased risk for poor short- and long-term outcomes compared with those treated with indomethacin. Prophylaxis with indomethacin in the first 24 hours of life did not modify the subsequent outcomes of patent ductus arteriosus therapy.

Ibuprofen versus continuous indomethacin in premature neonates with patent ductus arteriosus: is the difference in the mode of administration?

Ibuprofen has been proposed as a preferential alternative to indomethacin in treating patent ductus arteriosus (PDA), because it is purported to have less renal, mesenteric, and cerebral vasoconstrictive effects. However, short and long-term safety concerns regarding ibuprofen remain. Continuous slow infusion of indomethacin also eliminates peripheral vasoconstriction and may thus offer similar benefits to ibuprofen without safety concerns. In this study, our objective was to show that treating a PDA with continuous indomethacin is similar to ibuprofen in its effect on urine output, renal function, and blood flow velocities in the renal, superior mesenteric, and anterior cerebral arteries. Sixty four prematures with PDA were randomly, prospectively assigned to either treatment. PDA closure rates were similar (74 versus 59%; p = 0.123). Nine indomethacin-treated babies (29%) versus twelve ibuprofen babies (38%) underwent repeated therapy (p = 0.656). Two indomethacin and four ibuprofen infants required surgical ligation (p = 0.672). Serum creatinine, oliguria, estimated glomerular filtration rate, and fractional excretion of sodium were similar in both groups, as were blood flow velocity parameters in the vessels studied. There were no differences in necrotizing enterocolitis, BPD, intraventricular hemorrhage, and/or retinopathy of prematurity. In conclusion, PDA treatment with either continuous indomethacin infusion or ibuprofen was equally devoid of adverse renal effects and/or peripheral vasoconstrictive effects.

Multiple courses of indomethacin and neonatal outcomes in premature infants

The objective of this retrospective cohort study was to determine patent ductus arteriosus (PDA) closure rate with multiple short courses (three doses) of postnatal indomethacin and compare neonatal outcomes in infants who received two versus three courses of indomethacin for PDA closure. Infants <34 weeks' gestational age born between January 2000 and December 2004 at the University of Maryland Medical Center and who received two or more short courses of indomethacin were included. Outcome measures were ductal closure rate and neonatal outcomes. Of 61 infants who were identified to have received two or more courses of indomethacin, 26 infants closed their ductus after the second course (response rate, 42%). Of the 35 infants who failed ductal closure after two courses, 11 infants had their ductus ligated and 23 received a third course of indomethacin. Of 23 who received a third course, 10 closed their ductus (response rate, 43%). There was no significant difference in the incidence of chronic lung disease, severe retinopathy of prematurity, necrotizing enterocolitis, renal function, or mortality between infants who received two and those who received three courses of indomethacin. Infants exposed to three courses of indomethacin had a statistically nonsignificant increased incidence of periventricular leukomalacia (p = 0.08; adjusted odds ratio = 4.8; 95% CI, 0.8-30) and remained in the hospital for a longer duration (p = 0.02) compared to infants exposed to two courses of indomethacin. We conclude that multiple courses of indomethacin may be associated with a ductal closure. However, the requirement for a third course may be associated with an increased risk of periventricular leukomalacia.

Patent ductus arteriosus ligation in neonates: preoperative predictors of poor postoperative outcomes

PURPOSE

The purpose of this study was to identify preoperative predictors of adverse outcomes in infants undergoing surgical ligation of patent ductus arteriosus (PDA).

METHODS

Charts of all neonates who underwent PDA ligation at Texas Children's Hospital (Houston, TX) between 2001 and 2006 were retrospectively reviewed with specific attention to preoperative clinical characteristics, echocardiographic details, operative morbidity, and postoperative outcomes. Infants with other cardiac anomalies or right-to-left or bidirectional PDA shunt were excluded.

RESULTS

Eighty-two neonates were included (mean gestational age, 27 weeks; mean birth weight, 1000 g). There were no intraoperative complications. Preoperative symptoms related to respiratory insufficiency, hypotension, apnea, and pulmonary edema improved after ligation (P < .001). Birth weight, age at ligation, and indomethacin use did not correlate with postoperative outcome; however, lower gestational age, lower blood pressure, and lower shunt peak velocity predicted longer time to extubation by multiple analysis techniques (P < .0001). Linear regression (controlling for gestation, birth weight, and mean arterial pressure) showed inverse correlation between peak velocity and postoperative days on the ventilator (95% confidence interval, 47.18 to -12.25; P = .001).

CONCLUSION

The PDA ligation can be accomplished safely; however, some neonates have prolonged recovery. Lower gestational age and low peak velocity (<2.6 m/s) at the PDA shunt correlate with lengthened ventilator requirement after surgery.

Prevention and 18-month outcomes of serious pulmonary hemorrhage in extremely low birth weight infants: results from the trial of indomethacin prophylaxis in preterms

OBJECTIVES

A patent ductus arteriosus is a risk factor for pulmonary hemorrhage; however, despite halving the incidence of patent ductus arteriosus, indomethacin prophylaxis did not reduce the rate of pulmonary hemorrhage in the Trial of Indomethacin Prophylaxis in Preterms. Inclusion of mild bleeds after trauma to the upper airways may have masked a beneficial drug effect. Using the Trial of Indomethacin Prophylaxis in Preterms database, we studied the effect of prophylactic indomethacin on the prevention of serious hemorrhages in extremely low birth weight infants. We also compared the 18-month outcomes of infants with and without a serious pulmonary bleed.

METHODS

Pulmonary hemorrhage was classified as serious when it was treated with increased ventilator support, a higher concentration of oxygen, or transfusion of blood products. The cumulative risk for serious pulmonary hemorrhage was estimated for the first week of life and for the entire NICU stay. Poor outcome at a corrected age of 18 months was death or survival with cerebral palsy, cognitive delay, blindness, and/or deafness.

RESULTS

A total of 123 (10.2%) of 1202 infants developed a serious pulmonary hemorrhage. During week 1, prophylactic indomethacin reduced the risk for serious pulmonary hemorrhage by 35%; however, during the entire NICU stay, the risk for such hemorrhages was decreased by only 23%. A reduced risk for patent ductus arteriosus explained 80% of the beneficial effect of prophylactic indomethacin on serious pulmonary bleeds. The risks for death or for survival with neurosensory impairment were doubled after a serious pulmonary hemorrhage.

CONCLUSIONS

Extremely low birth weight infants with serious pulmonary hemorrhage have an increased risk for poor long-term outcome. Prophylactic indomethacin reduces the rate of early serious pulmonary hemorrhage, mainly through its action on patent ductus arteriosus. Prophylactic indomethacin is less effective in preventing serious pulmonary hemorrhages that occur after the first week of life.

Predictors of ductal closure and intestinal complications in very low birth weight infants treated with indomethacin

OBJECTIVE

To describe factors associated with failure of patent ductus arteriosus closure and development of gastrointestinal complications in subjects treated with indomethacin.

STUDY DESIGN

Infants <or=30 weeks and <1,500 g delivered between 1997-2003 with patent ductus arteriosus treated with indomethacin were included in this single-center retrospective study. Risk factors for failed ductal closure rates and gastrointestinal complications were identified with uni- and multivariable analyses.

RESULTS

Among 210 subjects treated with indomethacin, ductal closure increased from 43% at 23 weeks to 87% at 27 weeks (OR 1.51 per week gestation, 95% CI 1.14-2.01, p = 0.004) and was unchanged thereafter. Gastrointestinal complications decreased with increasing gestational age (OR 0.67/week, 95% CI 0.52-0.84) but increased with male gender (OR 2.41, 95% CI 1.07-5.45). SNAP-II (Score for Neonatal Acute Physiology-II) scores at birth and at the time of first indomethacin therapy were not associated with likelihood of closure or with gastrointestinal complications. Duration of ductal patency was not associated with risk of necrotizing enterocolitis or intestinal perforation after adjusting for gestational age and gender.

CONCLUSIONS

Ductal closure with indomethacin is linearly associated with gestational age in infants <or=27 weeks. Illness severity at the time of treatment is not predictive of treatment outcome or gastrointestinal complications. The duration of ductal patency is not associated with an increase in adjusted risk of necrotizing enterocolitis or intestinal perforation in patients treated with indomethacin.

Patent ductus arteriosus and its treatment as risk factors for neonatal and neurodevelopmental morbidity

OBJECTIVES

The purpose of this work was to determine whether the reported association between neonatal morbidities and a patent ductus arteriosus is because of the left-to-right patent ductus arteriosus shunt itself, the therapies used to treat it, or the immaturity of the infants who are likely to develop a patent ductus arteriosus.

METHODS

A total of 446 infants (<28 weeks' gestation) were treated with the same patent ductus arteriosus care-oriented protocol, and logistic regression analysis was used to examine the effects of several patent ductus arteriosus-related variables (presence of a symptomatic patent ductus arteriosus, the number of indomethacin doses used, the ductus response to indomethacin, and the use of surgical ligation) on the incidence of retinopathy of prematurity, necrotizing enterocolitis, chronic lung disease, death, and neurodevelopmental impairment.

RESULTS

Most of the predictive effects that the presence of a patent ductus arteriosus and its treatment had on neonatal morbidity could be accounted for by the infants' immature gestation. Use of surgical ligation, however, was significantly associated with the development of chronic lung disease and was independent of immature gestation, other patent ductus arteriosus-related variables, or other perinatal and neonatal risk factors known to be associated with chronic lung disease.

CONCLUSIONS

These findings add to the growing uncertainty about the benefits and risks of surgical ligation during the neonatal period.

Indomethacin use for the management of patent ductus arteriosus in preterms: a web-based survey of practice attitudes among neonatal fellowship program directors in the United States

The objective of this study was to determine whether neonatal-perinatal fellowship programs (NFTPs) in the United States vary in indomethacin use for the management of patent ductus arteriosus (PDA) in < or =28 week gestational age infants at birth. A 53-item web-based survey was sent to 84 NFTP directors who received prenotification, followed 2 weeks later by a reminder letter. A total of 56 NFTP directors responded (67% maximum response rate). Wide variation exists in the maximum number of indomethacin courses used to close ductus, use of indomethacin for reopened PDA beyond 14 days, ductal closure definition, contraindications before consideration of indomethacin, interventions for contraindications, and reported ductal closer rate after each indomethacin course. Indomethacin therapy for symptomatic PDA and short course of indomethacin are common practices. Indomethacin use for the management of PDA in premature infants varies among NFTP directors. Practice attitudes may explain variations in ductal closure and ligation rates. Because practice variations may have implications for long-term outcome of vulnerable premature infants, studies relevant to the management of PDA in premature infants are needed.

Enhanced intensive care for the neonatal ductus arteriosus

Failure of ductal closure is common in extremely low birth weight infants with significant postnatal morbidities from both pulmonary overcirculation (i.e. chronic lung disease) and/or systemic hypoperfusion (i.e. necrotizing enterocolitis). Early clinical signs of a hemodymanically significant ductus may be non-specific (i.e. hypotension, increasing ventilator requirements, metabolic acidosis) necessitating early screening by echocardiography. Cyclooxygenase inhibitors remain the first-line treatment option. Indomethacin remains the most commonly used agent, despite comparable efficacy and reduced risk of adverse events with ibuprofen. Surgical intervention is recommended after failure of medical therapy, contraindications to medical treatment or fulminating duct-related cardiorespiratory deterioration. Wherever possible, surgical intervention in ELBW infants should be avoided in the first week of life due to the potential risks of ischemia-reperfusion cerebral hemorrhage. The postoperative course is often complicated by left ventricular failure, pulmonary edema, and/or hemodynamic instability requiring close monitoring and physiologically relevant therapeutic interventions.

Prevalence of spontaneous closure of the ductus arteriosus in neonates at a birth weight of 1000 grams or less

OBJECTIVE

Ductus arteriosus (DA) closure occurs within 96 hours in >95% of neonates >1500 g in birth weight (BW). The prevalence and postnatal age of spontaneous ductal closure in neonates < or =1000 g in BW (extremely low birth weight [ELBW] neonates) remain unclear, as does the incidence of failure to close with indomethacin. Therefore, we prospectively examined the prevalence, postnatal age, and clinical variables associated with spontaneous DA closure, occurrence of persistent patent DA, and indomethacin failure in ELBW neonates.

METHODS

Neonates delivered at Parkland Memorial Hospital from February 2001 through December 2003 were studied. Those with congenital heart defects or death <10 days postnatally were excluded. Echocardiograms were performed 48 to 72 hours postnatal and every 48 hours until 10 days postnatally.

RESULTS

We studied 122 neonates with BW of 794 +/- 118 (SD) g and estimated gestational age (EGA) of 26 +/- 2 weeks. Spontaneous permanent DA closure occurred in 42 (34%) neonates at 4.3 +/- 2 days postnatally, with 100% closure by 8 days. These neonates were more mature, less likely to have received antenatal steroids or have hyaline membrane disease (HMD; 52% vs 79%), and more likely to be growth restricted (31% vs 5%) and delivered of hypertensive women. Using regression analysis, EGA and absence of antenatal steroids and HMD predicted ductal closure. Ten (8%) neonates with early DA closure reopened and required medical/surgical closure. Eighty neonates had persistent patent DA; 7 were surgically ligated, and 5 remained asymptomatic, with 4 of 5 closing after 10 days postnatally. Sixty-eight (85%) received indomethacin at 6.2 +/- 4 days postnatally; 41% failed therapy and had no distinguishing characteristics.

CONCLUSIONS

Spontaneous permanent DA closure occurs in >34% of ELBW neonates and is predicted by variables related to maturation, for example, EGA and an absence of HMD, whereas indomethacin failure could not be predicated.

Consequences of Delayed Surgical Closure of Patent Ductus Arteriosus in Very Premature Infants

BACKGROUND

Surgical closure of ductus arteriosus is commonly indicated in premature newborns. The aim of this study was to assess short-term and mid-term effects of delayed surgical closure of the ductus arteriosus on respiratory and digestive outcome in extremely preterm infants.

METHODS

We retrospectively studied 58 infants less than 28 weeks gestational age who underwent surgical closure of ductus arteriosus between January 1997 and December 2002. Nine infants with intrauterine growth restriction and major congenital malformation were excluded from the study. Criteria for surgical closure of ductus arteriosus were: (1) medical treatment failure (ie, indomethacin or ibuprofen) and (2) hemodynamically patent ductus arteriosus: systemic arterial pressure less than gestational age in mm Hg, heart failure, left atrial-aortic root ratio greater than 1.6, mean velocity in the left pulmonary artery greater than 0.6 m/s, and ductus arteriosus diameter greater than 3 mm. Infants were divided into two groups: (1) the early group who had surgery before 21 days of life (n = 31), and (2) the late group who had surgery after 21 days of life (n = 27). Preoperative and postoperative criteria were compared between the two groups (ie, gestational age, birth weight, hemodynamic, ventilatory, and echographic [left atrial-aortic root ratio, mean velocity in the left pulmonary artery] parameters).

RESULTS

Preoperative gestational age and birth weight did not differ between the two groups. In the early group, gestational age was 26 weeks (range, 23 to 28 weeks and birth weight was 800 g (range, 630 to 1,240 g). In the late group, gestational age was 26 weeks (range, 24 to 28 weeks) and birth weight was 840 g (530 to 1,130 g). Hemodynamic, ventilatory, and echographic parameters were similar in both groups. Rate of bronchopulmonary dysplasia was similar in both groups. However, at 24 hours post surgery, median FiO2 was higher in the late group (28% [range, 21% to 65%]) than in early group (21% [range, 21% to 60%]) (p < 0.05). Furthermore, full oral feeding was acquired later in the late group (57 days of life [range, 30 to 136 days]) than in the early group (37 days of life [range, 27 to 84 days]) (p < 0.01), and body weight at 36 weeks of post-conceptional age was higher in the early group at 1,800 g (range, 1,250 to 2,750 g) than in the late group at 1,607 g (1,274 to 2,200 g) (p < 0.05).

CONCLUSIONS

Our findings show that early surgical closure of the ductus arteriosus (< 3 weeks of life) is associated with shortened delay for full oral feeding and improved body growth when compared with late surgical closure (> 3 weeks of life).