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

Lung ultrasound score predicts patent ductus arteriosus ligation among neonates ≤25 weeks

BACKGROUND

This prospective study aimed to investigate whether lung ultrasound score (LUSs) can predict the patent ductus arteriosus (PDA) ligation.

METHODS

Preterm infants ≤25 weeks of gestational age (GA) were enrolled. A lung ultrasound was performed on the 14th day of life. Each lung zone was given a score between 0 and 4. A receiver-operating characteristic (ROC) curve was constructed to evaluate the ability of the LUSs for predicting ligation.

RESULTS

A total of 81 infants were eligible with a median GA and birth weight (BW) of 25 weeks (24.1-25.2) and 710 g (645-770), respectively. The median time from birth to ligation was 35 days (32-51). Those who underwent ligation had a longer time of mechanical ventilation (34 [26-39] vs. 19 [12-30], p < 0.001), shorter time of noninvasive respiratory support (39 [32-51] vs. 50 [41.5-57], p < 0.01), higher incidence of the bronchopulmonary dysplasia (BPD) (p < 0.01), and severe BPD (p < 0.001). The LUSs had an area under the ROC of 0.96 (95% confidence interval: 0.93-0.99) for the prediction of ligation. A LUSs cutoff of 36 has a sensitivity and specificity of 96% and 86% and positive and negative predictive values of 82% and 98%, respectively.

CONCLUSIONS

LUSs at an early stage of life can predict PDA ligation in extremely preterm infants. It would be helpful to reduce morbidity by reducing the duration and magnitude of respiratory support.

Combination pharmacotherapy for patent ductus arteriosus: Rationale and evidence

While cyclooxygenase inhibitors have been the most common medications used to facilitate earlier closure of patent ductus arteriosus in preterm infants, adverse effects and low efficacy in extremely low gestational age neonates (ELGANs) have highlighted a need for alternative options. Combination therapy with acetaminophen and ibuprofen is a novel strategy for PDA treatment in ELGANs, as it may facilitate higher ductal closure rates via additive action on two separate pathways inhibiting prostaglandin production. Initial small observational studies and pilot randomized clinical trials indicate potentially higher efficacy of the combination regime to induce ductal closure in comparison to treatment with ibuprofen alone. In this review, we examine the potential clinical impact of treatment failure in ELGANs with significant PDA, highlight the biological rationale in support of studying combination therapy, and review the randomized and non-randomized studies to date. With the rising number of ELGANs receiving neonatal intensive care, who are vulnerable to PDA-related morbidities, there is an urgent need for adequately powered clinical trials to systematically investigate the efficacy and safety of combination therapy for PDA treatment.

Vascular and pulmonary effects of ibuprofen on neonatal lung development

BACKGROUND

Ibuprofen is a nonsteroidal anti-inflammatory drug that is commonly used to stimulate closure of a patent ductus arteriosus (PDA) in very premature infants and may lead to aberrant neonatal lung development and bronchopulmonary dysplasia (BPD).

METHODS

We investigated the effect of ibuprofen on angiogenesis in human umbilical cord vein endothelial cells (HUVECs) and the therapeutic potential of daily treatment with 50 mg/kg of ibuprofen injected subcutaneously in neonatal Wistar rat pups with severe hyperoxia-induced experimental BPD. Parameters investigated included growth, survival, lung histopathology and mRNA expression.

RESULTS

Ibuprofen inhibited angiogenesis in HUVECs, as shown by reduced tube formation, migration and cell proliferation via inhibition of the cell cycle S-phase and promotion of apoptosis. Treatment of newborn rat pups with ibuprofen reduced pulmonary vessel density in the developing lung, but also attenuated experimental BPD by reducing lung inflammation, alveolar enlargement, alveolar septum thickness and small arteriolar wall thickening.

CONCLUSIONS

In conclusion, ibuprofen has dual effects on lung development: adverse effects on angiogenesis and beneficial effects on alveolarization and inflammation. Therefore, extrapolation of the beneficial effects of ibuprofen to premature infants with BPD should be done with extreme caution.

Comparison of standard versus high-dose ibuprofen for the treatment of hemodynamically significant patent ductus arteriosus in preterm infants

OBJECTIVE

To evaluate the effectiveness and safety of standard vs. high-dose ibuprofen for the treatment of hemodynamically significant patent ductus arteriosus(hs-PDA).

STUDY DESIGN

A retrospective study of preterm infants who received either standard (10-5-5 mg/kg/day) or high (postnatal age 1-3 days: 10-5-5 mg/kg/day; 3-5 days: 15-7.5-7.5 mg/kg/day; >5 days: 20-10-10 mg/kg/day) dose ibuprofen for hs-PDA was conducted.

RESULT

Sixty preterm infants with a mean birthweight of 898.2 (±262.6) g and mean gestational age of 26.3 (±0.6) weeks were included. High-dose ibuprofen was associated with a 21%(95% CI, -1.87 to 39.06%; p = 0.07) absolute reduction in PDA ligation compared to standard-dose ibuprofen. On adjusted analysis, receipt of standard-dose ibuprofen (OR 7.37, 95% CI, 1.2-45.27; p = 0.03) independently predicted increased PDA ligation risk. There were no differences in oliguria, NEC, or BPD between groups.

CONCLUSION

High-dose ibuprofen may significantly reduce PDA ligations. No difference in the safety profile with high-dose ibuprofen as compared to the standard-dose regimen was demonstrated.

Cost-effectiveness of Oral Versus Intravenous Ibuprofen Therapy in Preterm Infants With Patent Ductus Arteriosus in the Neonatal Intensive Care Setting: A Cohort-based Study

PURPOSE

Use of ibuprofen for the patent ductus arteriosus (PDA) has become increasingly common. This study aimed to evaluate the clinical and economic impact of oral ibuprofen versus intravenous ibuprofen for PDA among preterm infants.

METHODS

This retrospective, cohort-based pilot study examined the clinical and economic associations of oral versus intravenous ibuprofen for PDA. A decision-analytic model was constructed, from the hospital perspective, to follow the oral versus intravenous administrations of ibuprofen for PDA and their clinical and economic consequences. The course regimen of either formulation was an initial 10 mg/kg followed by 5 mg/kg at 24- and 48-h intervals. Clinical and resource utilization data were extracted from Cerner medical database, from 2014 through 2018, at the tertiary neonatal intensive care unit setting in Qatar. The primary outcome measures were the rate of successful closure based on the ductal diameter measure after the first course of treatment and the overall direct medical cost of PDA management. A population of 118 neonates was required for results with 80% power and 0.05 significance. Sensitivity analyses involving unit costs and a subgroup analysis based on gestational age and birth weight, added to a second-order probabilistic analysis of all model inputs, were performed.

FINDINGS

Forty infants were available for inclusion in the oral ibuprofen study group, not achieving the desired sample size, with successful PDA closure reported in 64% of cases compared with a reduced success of 36% with intravenous ibuprofen (n = 59) (risk ratio = 0.56; 95% CI, 0.32-0.97; P = 0.04), which was associated with economic advantage to oral ibuprofen. The probabilistic analysis illustrated that oral ibuprofen costs less than intravenous ibuprofen in 72% of patient cases, with QAR 48,751 (US $13,356) (95% CI, QAR 47,500-50,000, US $13,014-$13,699) in mean savings. Sensitivity analyses confirmed the robustness of study conclusions and found that the rate of closure success versus failure was the most influential on results, followed by the occurrence of adverse drug events with both intravenous and oral ibuprofen. Although both ibuprofen formulations had similar safety profiles (P = 0.16), the intravenous formulation was associated with a larger number of adverse drug effects.

IMPLICATIONS

This is the first cost-effectiveness evaluation of oral versus intravenous formulations of ibuprofen among infants with PDA. The oral ibuprofen might be associated with an enhanced ductal closure at a considerably lower cost. The study results support recent trends in neonatal intensive care unit practices in favor of the oral administration of ibuprofen.

Factors affecting the effectiveness of oral ibuprofen in the treatment of patent ductus arteriosus in preterm infants

Background Data on the effectiveness of oral ibuprofen treatment for patent ductus arteriosus are limited, and the factors affecting its effectiveness remain unclear. Objective The aim was to identify the potential factors affecting the clinical effectiveness of oral ibuprofen in preterm infants. Setting Neonatal intensive care unit in a prefecture-level maternal and child healthcare hospital in China. Method Over a 5-years period, the medical records of 327 preterm infants with patent ductus arteriosus who were admitted to the neonatal intensive care unit of our hospital to receive a single course of oral ibuprofen were retrospectively reviewed. Main outcome measures The prevalence of risk factors affecting the effectiveness of oral ibuprofen. Results In total, 201 (61.47%) preterm infants were considered to have undergone "effective therapy" and classified accordingly, whereas 11 (3.36%) showed certain adverse events. Factors affecting therapeutic effectiveness were postnatal age at the initiation of treatment and Day 1/Day 0 ratio of urine output/fluid intake during the treatment course, with odds ratios of 0.892 (95% CI: 0.835-0.953; P = 0.001) and 0.473 (95% CI 0.265-0.845; P = 0.011), respectively. Conclusion A single course of oral ibuprofen for patent ductus arteriosus closure among preterm infants is effective and safe. Preterm infants with postnatal age of ≤ 9 days at the initiation of treatment and Day 1/Day 0 ratio of ≤ 0.708 of the urine output/fluid intake during the treatment course can be considered predictors of effectiveness of patent ductus arteriosus.

A Matched Case Control Study of Surgically and Non-surgically Treated Patent Ductus Arteriosus in Extremely Pre-term Infants

Introduction: There are still uncertainties about the timing and indication for surgical ligation of patent ductus arteriosus (PDA) in pre-term infants, where lower gestational age (GA) usually is predictive for surgical treatment. Objective: Our aim was to assess differences in clinical characteristics and outcomes between surgically treated and matched non-surgically treated PDA in extremely pre-term infants. Methods: All extremely pre-term infants born 2010-2016 with surgically treated PDA (Ligated group; n = 44) were compared to non-surgically treated infants (Control group; n = 44) matched for gestational age (+/-1 week) and time of birth (+/-1 month). Perinatal parameters, echocardiographic variables, details of pharmacological PDA treatment, morbidity, and mortality were assessed. Result: Mean GA and birthweight were similar between the Ligated group (24⁺⁵ ± 1⁺³ weeks and 668 ± 170 g) and the Control group (24⁺⁵ ± 1⁺³ weeks and 704 ± 166 g; p = 1.000 and p = 0.319, respectively). Infants in the Ligated group had larger ductal diameters prior to pharmacological treatment, and lack of diameter decrease and PDA closure after treatment (p = 0.022, p = 0.043 and 0.006, respectively). Transfusions, post-natal steroids and invasive respiratory support were more common in the Ligated group. Except for a higher incidence of severe bronchopulmonary dysplasia (BPD) in the Ligated group there were no other differences in outcomes or mortality between the groups. Conclusion: Early large ductal diameter and reduced responsiveness to pharmacological treatment predicted the need for future surgical ligation in this matched cohort study of extremely pre-term infants where the effect of GA and differences in treatment strategies were excluded. Besides an increased incidence of severe BPD in the Ligated group, no other differences in morbidity or mortality were detected.

Use of combination therapy with acetaminophen and ibuprofen for closure of the patent ductus arteriosus in preterm neonates

Objective

To compare effectiveness and safety of combination therapy (acetaminophen and ibuprofen) to monotherapy (ibuprofen, indomethacin, or acetaminophen alone) in treatment of the patent ductus arteriosus (PDA) in premature neonates.

Methods

This was a retrospective cohort study of neonates admitted to a tertiary-level neonatal intensive care unit. Included neonates were born at <32 weeks gestation and received pharmacotherapy for PDA closure. Based on the primary therapy received, our cohort was divided into the following four groups: indomethacin alone, ibuprofen alone, acetaminophen alone, and ibuprofen and acetaminophen (in combination). Baseline characteristics, effectiveness, safety, neonatal mortality, and morbidities rates between these groups were compared.

Results

One hundred and forty neonates were analyzed; 17 received combination therapy, and 123 neonates received monotherapy: 22 (17.9%) ibuprofen, 29 (23.6%) acetaminophen, and 72 (58.5%) indomethacin. The PDA closure rates were 41.7% for indomethacin, 41.2% for combination therapy, 37.9% for acetaminophen, and 31.8% for ibuprofen (P=0.100). Rates of adverse effects were comparable between the groups.

Conclusion

The rate of ductal closure was not different between combination therapy and monotherapy. The study did not demonstrate any increased adverse effects in the combination group. Future well-designed prospective clinical trials are needed to guide clinical practice.

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.

Transcatheter Closure of Patent Ductus Arteriosus in Premature Infants With Very Low Birth Weight

Background: The aim of this study was to describe our experience with transcatheter device closure of patent ductus arteriosus (PDA) in symptomatic low-birth-weight premature infants. Methods: We performed a retrospective study of infants born with a birth body weight of < 2,000 g and admitted to National Cheng Kung University Hospital from September 2014 to December 2019. Basic demographic and clinical information as well as echocardiographic and angiographic data were recorded. Results: Twenty-five premature infants (11 boys and 14 girls) born at gestational ages ranging between 22 and 35 weeks (mean, 25 weeks) were identified. The mean age at procedure was 34.5 ± 5.5 days, and the mean weight was 1,209 ± 94 g (range, 478-1,980 g). The mean diameter of the PDA was 3.4 ± 0.2 mm (range, 2.0-5.4 mm). The following devices were used in this study: Amplatzer Ductal Occluder II additional size (n = 20), Amplatzer Vascular Plug I (n = 1), and Amplatzer Vascular Plug II (n = 4). Complete closure was achieved in all patients. The mean follow-up period was 30.1 ± 17.3 months (range, 6-68 months). In total, 3 patients had left pulmonary artery (LPA) stenosis and 1 patient had coarctation of the aorta during the follow-up period. Younger procedure age and smaller procedure body weight were significantly associated with these obstructions. Conclusions: Performing transcatheter PDA closure in symptomatic premature infants weighing more than 478 g is feasible using currently available devices; moreover, the procedure serves as an alternative to surgery.

Early echocardiography does not predict subsequent treatment of symptomatic patent ductus arteriosus in extremely preterm infants

AIM

To determine whether early echocardiographic ductal parameters identified infants who subsequently received medical or surgical treatment of the patent ductus arteriosus (PDA).

METHODS

Infants <29 weeks had PDA size in 2D and colour, flow velocity and patterns obtained on days 1 and 3. Infants were followed up to identify those subsequently receiving treatment for symptomatic PDA by clinicians who were unaware of scan results. Receiver operator characteristics curves and logistic regression were performed.

RESULTS

Sixty infants were studied. Mean (SD) gestation and birthweight were 25.8 (1.5) weeks and 817 (190) grams, respectively. Twenty-four (40%) infants received medical treatment, and nine (15%) infants received surgical ligation of PDA at a median age of 12 and 37 days, respectively. PDA size on days 1 and 3, change in ductal size between days 1 and 3, flow pattern/velocity did not predict whether infants subsequently received medical or surgical management of PDA. Using logistic regression, gestation (p = 0.006) was the only factor that predicted whether infants would subsequently receive medical or surgical treatment for PDA in this cohort.

CONCLUSION

Echocardiographic ductal parameters on day 1 or 3 did not identify infants who received PDA treatment. Gestation was the most powerful predictor for receiving medical or surgical treatment of PDA.

Patent ductus arteriosus in preterm infants born before 30 weeks' gestation: high rate of spontaneous closure after hospital discharge

AimThe aim of this study was to determine the spontaneous closure rate of patent ductus arteriosus at a 2-year follow-up, following failed medical therapy and beyond initial hospital discharge, and to evaluate in-hospital spontaneous or pharmacological closure rates.Materials and methodsA retrospective evaluation was conducted in a cohort of preterm infants admitted to the Neonatal ICU of Ancona between January, 2004 and June, 2013. Inclusion criteria were gestational age between 24+0 and 29+6 weeks or birth weight 1.5 mm, a left atrium-to-aorta ratio >1.4, and/or reversal of end-diastolic flow in the aorta >30% of the anterograde. First-line treatment was intravenous ibuprofen. Intravenous indomethacin was used if ibuprofen failed. Surgical ligation was considered in haemodynamically significant patent ductus arteriosus after medical treatment.

RESULTS

A total of 593 infants met the inclusion criteria, and patent ductus arteriosus was diagnosed in 317 (53.4%). Among them, 283 (89.3%) infants had haemodynamically significant patent ductus arteriosus, with pharmacological closure achieved in 228 (80.6%) infants and surgical ligation performed in 20 (7.1%). Follow-up at 24 months was available for 39 (81.3%) of 48 infants with patent ductus arteriosus at the hospital discharge: 36 (92.3%) underwent spontaneous closure, two (5.1%) underwent surgical ligation, and one (2.6%) had a patent ductus arteriosus.DiscussionA significant number of patent ductus arteriosus that fail pharmacological closure undergo spontaneous closure by the age of 2 years. This information should be taken into account when considering surgery or additional attempts of pharmacological closure.

Simulation-based suggestions to improve ibuprofen dosing for patent ductus arteriosus in preterm newborns

Purpose

Ibuprofen is the drug of choice for treatment of patent ductus arteriosus (PDA). There is accumulating evidence that current ibuprofen-dosing regimens for PDA treatment are inadequate. We aimed to propose an improved dosing regimen, based on all current knowledge.

Methods

We performed a literature search on the clinical pharmacology and effectiveness of ibuprofen. (R)- and (S)-ibuprofen plasma concentration-time profiles of different dosing regimens were simulated using a population pharmacokinetic model and evaluated to obtain a safe, yet likely more efficacious ibuprofen exposure.

Results

The most effective intravenous ibuprofen dosing in previous clinical trials included a first dose of 20 mg kg⁻¹ followed by 10 mg kg⁻¹ every 24 h. Simulations of this dosing regimen show an (S)-ibuprofen trough concentration of 43 mg L⁻¹ is reached at 48 h, which we assumed the target through concentration. We show that this target can be reached with a first dose of 18 mg kg⁻¹, followed by 4 mg kg⁻¹ every 12 h. After 96 h postnatal age, the dose should be increased to 5 mg kg⁻¹ every 12 h due to maturation of clearance. This twice-daily dosing has the advantage over once-daily dosing that an effective trough level may be maintained, while peak concentrations are substantially (22%) lower.

Conclusions

We propose to improve intermittent ibuprofen-dosing regimens by starting with a high first dose followed by a twice-daily maintenance dosing regimen that requires increase over time and should be continued until sufficient effect has been achieved.

Electronic supplementary material

The online version of this article (10.1007/s00228-018-2529-y) contains supplementary material, which is available to authorized users.

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.

Patent Ductus Arteriosus in the Preterm Infant: Diagnostic and Treatment Options

BACKGROUND

The incidence of hemodynamically significant patent ductus arteriosus (hsPDA) increases with decreasing gestational age and is associated with many common morbidities of extreme prematurity. Controversies remain surrounding the definition of hsPDA, the population of infants requiring treatment, the appropriate timing and method of treatment, and the outcomes associated with PDA and its therapies.

PURPOSE

This integrative literature review focuses on diagnostic and treatment recommendations derived from the highest levels of evidence.

SEARCH STRATEGY

PubMed and CINAHL were searched using key words "neonatal" and "patent ductus arteriosus" to discover the highest levels of evidence surrounding diagnosis, treatment methods, and outcomes.

FINDINGS/RESULTS

The lack of consensus surrounding the diagnosis and clinical significance of PDA hinders meta-analysis across studies and confounds understanding of appropriate management strategies. Novel biomarkers, pharmaceutical choices, and transcatheter closure methods are expanding diagnostic and treatment options.

IMPLICATIONS FOR PRACTICE

Infants weighing less than 1000 g are at highest risk. Prophylactic closure is no longer recommended, although early asymptomatic therapy is still preferred by some to avoid prolonged pulmonary overcirculation or decreased renal and gut perfusion. Conservative treatment measures such as fluid restriction and diuretic administration have not consistently proven effective and are in some instances detrimental. Cyclooxygenase inhibitors are effective but have adverse renal and mesenteric effects. Oral ibuprofen is associated with lower instance of necrotizing enterocolitis.

IMPLICATIONS FOR RESEARCH

Well-defined staging criteria would aid in comparison and meta-analysis. Trials that include a control group that receives no therapy may help separate the outcomes associated with prematurity from those associated with PDA.

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.

Early predictive echocardiographic features of hemodynamically significant patent ductus arteriosus in preterm VLBW infants

BACKGROUND

Patent ductus arteriosus (PDA) is associated with increased morbidity and mortality in very low-birthweight (VLBW) preterm infants due to significant left-to-right shunting, which leads to pulmonary edema/hemorrhage, intracranial hemorrhage, acute renal failure and necrotizing enterocolitis. In this prospective study, echocardiography was carried out in VLBW preterm infants soon after birth and at the end of 72 h to evaluate the relationship between early ductal anatomic features and significant ductal shunt during follow up.

METHODS

Preterm infants with a gestational age ≤ 28 weeks, birthweight < 1000 g and who had ductal patency during the first 6-12 h of life underwent color Doppler echocardiograms through the first 3 days after birth.

RESULTS

Fifty-eight patients were enrolled. The DA remained open in 42 preterm infants (72.4%) and was hemodynamically significant in 36 (62%) at the end of 72 h postnatal age. The preterm infants with hemodynamically significant PDA (hsPDA) had shorter ductal length from aortic to pulmonary insertion and from ductal constriction to pulmonary insertion in the initial exam. Cut-offs for these lengths were 5.2 and 1.7 mm, respectively. These parameters had significant univariate correlation with ductal closure time after treatment.

CONCLUSIONS

Echocardiographic features such as short ductal length and short or absent ductal constriction area can be used to predict hsPDA for early decision making strategies in VLBW preterm infants.

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.

Preterm infants who later require duct ligation show different vital signs and pH in early postnatal life

AIM

The study investigated early postnatal vital signs in very low birthweight (VLBW) infants who later developed patent ductus arteriosus (PDA). We hypothesised that the early postnatal course of vital signs and blood gas variables might differ between infants whose PDA closed spontaneously, those who responded to ibuprofen and those who later required PDA ligation.

METHODS

We analysed computerised records of VLBW infants born <28 weeks of gestational age, including vital signs, arterial pH values and echocardiographic data from the first postnatal days.

RESULTS

In total, 104 infants were included in the study. In the group of infants born <26 weeks of gestational age and requiring ibuprofen for PDA (n = 34), 12 infants ultimately required surgical ligation. Infants requiring ligation showed significantly lower oxygen saturation (p = 0.019), mean blood pressure (p = 0.034) and higher heart rate fluctuation ranges (p = 0.040) in the first five postnatal days than those who responded to ibuprofen. In multivariable logistic regression analysis, lower pH values in the first 48 h predicted the subsequent requirement for ligation independent of gestational age (p = 0.004).

CONCLUSION

Patients <26 weeks of gestational age requiring PDA ligation showed significant differences in the course of vital signs and pH during the first days of life.

Comparison of oral ibuprofen with oral indomethacin for PDA closure in Indian preterm neonates: a randomized controlled trial

Oral ibuprofen is being used as an alternative to indomethacin in medical management of patent ductus arteriosus (PDA), but limited data exist on oral efficacy of these drugs for PDA closure in India. To assess and compare the efficacy of oral ibuprofen and oral indomethacin for PDA closure in preterm Indian neonates, we designed a randomized controlled study on clinically diagnosed and echocardiographically confirmed hemodynamically significant PDA in preterm neonates. Patients were assigned to receive either oral ibuprofen at a dosage of 10, 5, 5 mg/kg every 24 h or three doses of oral indomethacin (0.20-0.25 mg/kg every 24 h) starting on the third day of life or when diagnosed. A second course of ibuprofen/indomethacin was given, if PDA failed to close within 48 h after the first course. Patients were monitored for complications like oliguria, bleeding, necrotizing enterocolitis, intraventricular hemorrhage, oxygen dependency, and gastrointestinal side effects. The baseline characteristics were comparable in both groups. Of the 83 children enrolled, 57.8 % received oral ibuprofen and 42.1 % received oral indomethacin. The overall closure rate of PDA was 60 and 65.7 % in the ibuprofen and indomethacin groups, respectively. Closure rate was significantly higher when the drugs were administered at an early postnatal age (<8 days) (83.3 % [p = 0.02] in the indomethacin group and 75 % [p = 0.03] in the ibuprofen group) in neonates >28 weeks (ibuprofen group 66.7 % [p = 0.02]; indomethacin group 65.5 % [p = 0.04]) and in babies with birth weight >1,000 g (ibuprofen group 62.2 %; indomethacin group 70 % [p = 0.04 in both groups]). Complications were similar in both groups. The efficacy of both drugs was similar. Poor closure in our study could be because of genetic differences in pharmacokinetics of drug metabolism in the Indian population. Regimens with higher doses or increased duration of treatment may increase the frequency of closure. Studies with larger numbers of subjects with evaluation of pharmacokinetic parameters are therefore required.

The Association between Patent Ductus Arteriosus and Perinatal Infection in A Group of Low Birth Weight Preterm Infants

OBJECTIVE

Patent ductus arteriosus (PDA) is an extremely common occurrence in very premature infants. Untreated symptomatic PDA may be associated with chronic lung disease. PDA has a major role in neonatal mortality and morbidity. We compared the efficacy and safety of oral versus intravenous ibuprofen for the pharmacological closure of PDA in low birth weight (LBW) preterm infants.

METHODS

A randomized, single-blinded, controlled study was performed on premature neonates at the neonatal unit, University Hospital for Obstetrics and Gynecology "Koço Gliozheni", Tirana, Albania from January 2010 to December 2012. The study enrolled 68 preterm infants with a confirmed and significant PDA. The preterm infants received either intravenous or oral ibuprofen randomly as an initial dose of 10 mg/kg, followed by 5 mg/kg at 24 and 48 h. Findings : 36 patients were treated with oral ibuprofen and 32 with intravenous ibuprofen during this period. After the first course of the treatment, the PDA closed in 30 (83.3%) of the patients assigned to the oral ibuprofen group versus 23 (71.8%) of those enrolled in the intravenous ibuprofen group (P=0.355). 15 patiens needed a second treatment course and they all (100%) had clinical signs of infection and positive blood culture. There was no reopening of the ductus after the closure.

CONCLUSION

Our data indicate that, for LBW infants, the rate of early ductal closure was comparable and the adverse effects were fewer with oral ibuprofen in comparison to the intravenous route. Association of PDA with perinatal infection has a negative impact in pharmacological closure of the ductus, increasing the need for a second course of treatment or for surgery.

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.

Primary surgical closure should be considered in premature neonates with large patent ductus arteriosus

BACKGROUND

Treatment for patent ductus arteriosus (PDA) in premature infants can consist of medical or surgical approaches. The appropriate therapeutic regimen remains contentious. This study evaluated the role of surgery in improving the survival of premature neonates weighing less than 1,500 g with PDA.

MATERIALS AND METHODS

From January 2008 to June 2011, 68 patients weighing less than 1,500 g with PDA were enrolled. The patients were divided into three groups: a group managed only by medical treatment (group I), a group requiring surgery after medical treatment (group II), and a group requiring primary surgical treatment (group III).

RESULTS

The rate of conversion to surgical methods due to failed medical treatment was 67.6% (25/37) in the patients with large PDA (≥2 mm in diameter). The number of patients who could be managed with medical treatment was nine which was only 20.5% (9/44) of the patients with large PDA. There was no surgery-related mortality. Group III displayed a statistically significantly low rate of development of bronchopulmonary dysplasia (BPD) (p=0.008). The mechanical ventilation time was significantly longer in group II (p=0.002).

CONCLUSION

Medical treatment has a high failure rate in infants weighing less than 1,500 g with PDA exceeding 2.0 mm. Surgical closure following medical treatment requires a longer mechanical ventilation time and increases the incidence of BPD. Primary surgical closure of PDA exceeding 2.0 mm in the infants weighing less than 1,500 g should be considered to reduce mortality and long-term morbidity events including BPD.

Therapeutic strategies, including a high surgical ligation rate, for patent ductus arteriosus closure in extremely premature infants in a North American centre

OBJECTIVE

To document the rate of surgical ligation of a patent ductus arteriosus (PDA) in extremely premature infants who had received more than one course of indomethacin. Outcomes were compared among three subgroups (ligation, further indomethacin and no further treatment) of infants who received at least one course of indomethacin, and between two subgroups (one course of indomethacin and more than one course) among infants who underwent ligation.

STUDY DESIGN

A retrospective chart review of all 23 weeks+0 days to 26 weeks+6 days' gestational age infants with a PDA born between 1994 and 2005 was performed. Secondary outcomes were compared among the subgroups.

RESULTS

The final study population consisted of 196 extremely premature infants with a PDA. The rate of surgical ligation in the 88 infants who received more than one course of indomethacin was 64%. The ligation subgroup, in comparison with the no further treatment subgroup, spent a greater median time on mechanical ventilation (39 versus 29 days, P<0.001) and in hospital (115 versus 92 days P=0.002), while trending toward lower mortality (18% versus 40%, P=0.07). The PDA closed following the first course of indomethacin in only 20% of infants.

CONCLUSIONS

A majority of extremely premature infants receiving more than one course of indomethacin underwent surgical ligation. Repeated indomethacin courses were generally well tolerated, but were mostly unsuccessful. Ligation appears to have potential risks and benefits. A randomized trial should be performed after studies define a hemodynamically significant PDA that will result in morbidity and/or mortality unless treated.

Comparison of oral Ibuprofen and intravenous indomethacin for the treatment of patent ductus arteriosus in extremely low birth weight infants

OBJECTIVE

There are few published reports concerning the efficacy of oral ibuprofen for the treatment of patent ductus arteriosus (PDA) in extremely low birth weight (ELBW) infants. Oral ibuprofen was compared to intravenous indomethacin regarding efficacy and safety in the treatment of PDA in infants weighting less than 1,000g at birth.

METHOD

This was a retrospective study in a single center. Data on ELBW infants who had an echocardiographically confirmed PDA were collected. The infants were treated with either intravenous indomethacin or oral ibuprofen. Rate of ductal closure, need for additional treatment, drug-related side effects or complications, and mortality were compared between the two treatment groups.

RESULT

26 infants who received indomethacin and 22 infants who received ibuprofen were studied. The overall rate of ductal closure was similar between the two treatments: it occurred in 23 of 26 infants (88.5%) treated with indomethacin, and in 18 of 22 infants (81.8%) treated with ibuprofen (p=0.40). The rate of surgical ligation (11.5% versus 18.2%; p=0.40) did not differ significantly between the two treatment groups. No significant difference was found in post-treatment serum creatinine concentrations between the two groups. There were no significant differences regarding additional side effects or complications.

CONCLUSION

In ELBW infants, oral ibuprofen is as efficacious as intravenous indomethacin for the treatment of PDA. There were no differences between the two drugs with respect to safety. Oral ibuprofen could be used as an alternative agent for the treatment of PDA in ELBW infants.

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.

The impact of patent ductus arteriosus in neonates with late onset sepsis: a retrospective matched-case control study

BACKGROUND

Late-onset sepsis (LOS) in neonates with patent ductus arteriosus (PDA) may predispose them to more complicated hospital courses. The objective of this study was to determine the incidence, the distribution of pathogens, and the clinical features of LOS in neonates with PDA and analyze their outcomes.

METHODS

The medical records were reviewed retrospectively of infants with PDA and LOS who were hospitalized in NICUs of Chang Gung Children's Hospital between January 2003 and December 2009. The clinical features of these infants were compared with a group of gestational age and birth body weight-matched neonates with LOS during the same period.

RESULTS

During this period, 224 neonates were found to have at least one event of blood-culture proven LOS and 79 (35.3%) were documented to have PDA. Although most LOS episodes (85/104, 81.7%) in neonates with PDA occurred after closure of PDA, neonates with PDA had a significantly higher rate of bronchopulmonary dysplasia (81.0% vs. 61.0%, p = 0.002) and a relatively higher rate of recurrent sepsis (25.3% vs. 15.2%, p = 0.079) than those without PDA. Longer durations of ventilator support and hospital stay were also noted in neonates with PDA as compared to those without (p = 0.001 and 0.005, respectively).

CONCLUSION

In neonates with LOS, the presence of PDA, even though it is aggressively treated with indomethacin or surgical intervention, may still contribute to the complexity of hospitalization. Close monitoring and aggressive treatments are warranted in these neonates with PDA.

Thrombocytopenia in the first 24 hours after birth and incidence of patent ductus arteriosus

BACKGROUND

Experimental studies suggest that platelet-triggered ductal sealing is critically involved in definite ductus arteriosus closure. Whether thrombocytopenia contributes to persistently patent ductus arteriosus (PDA) in humans is controversial. This was a retrospective study of 1350 very low birth weight (VLBW; <1500 g) infants, including 592 extremely low birth weight (ELBW; <1000 g) infants.

METHODS

All infants who had a platelet count in the first 24 hours after birth and an echocardiogram performed on day of life 4 to 5 were included. The incidence of thrombocytopenia was analyzed in infants with and without PDA, and in those who did or did not undergo PDA intervention. The impact of thrombocytopenia, gestational age, birth weight, gender, and sepsis on PDA was determined by receiver operating characteristic curve, odds ratio, and regression analyses.

RESULTS

Platelet numbers within the first 24 hours after birth did not differ between VLBW/ELBW infants with and without spontaneous ductal closure. Platelet numbers were not associated with subsequent PDA treatment. Low platelet counts were not related to failure of pharma-cologic PDA treatment and the need for subsequent surgical ligation. Lower gestational age or birth weight, male gender, and sepsis were linked to the presence of PDA in VLBW infants on day of life 4 to 5.

CONCLUSIONS

Thrombocytopenia in the first 24 hours after birth was not associated with PDA in this largest VLBW/ELBW infant cohort studied to date. Impaired platelet function, due to immaturity and critical illness, rather than platelet number, might play a role in ductus arteriosus patency.

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.

Failure of a repeat course of cyclooxygenase inhibitor to close a PDA is a risk factor for developing chronic lung disease in ELBW infants

BACKGROUND

The optimal treatment regimen or protocol for managing a persistent patent ductus arteriosus (PDA) in extremely low birth weight (ELBW) infants has not been well established. This study was aimed at evaluating the failure rate of a cyclooxygenase (COX) inhibitor (COI) for PDA closure and to determine the incidence of a PDA requiring ligation in ELBW infants. We examined the clinical characteristics and risk factors that may predict the clinical consequences of failure of PDA closure by COI.

METHODS

Medical information on 138 infants with birth weight (BW) < 1000 gm who survived for > 48 hours was retrieved. Clinical characteristics and outcomes of patients whose PDAs closed with COI were compared with those who did not close.

RESULTS

Of the 138 patients, 112 survived to discharge. Eighty (71.4%) of those who survived received 1-3 courses of COI treatment for a symptomatic PDA. A total of 32 (40%) failed COI treatment and underwent PDA ligation. Multivariable logistic regression analysis suggests that the observed differences in the outcomes in infants with or without symptomatic PDA can be explained by the babies with symptomatic PDA being more immature and sicker. No significant difference was seen in the incidence of chronic lung disease (CLD) in infants whose PDA was treated medically versus those who failed medical treatment and then underwent ligation. However, after adjusting for disease severity and other known risk factors, the odds ratio of developing CLD for surviving babies with a persistent PDA compared to those whose PDA was successfully closed with 1-2 courses of COI is 3.24 (1.07-9.81; p = 0.038).

CONCLUSIONS

When successfully treated, PDA in ELBW infants did not contribute significantly to the adverse outcomes such as CLD, retinopathy of prematurity (ROP) and age at discharge. This suggests that it is beneficial for a hemodynamically significant PDA to be closed. The failure of a repeat course of COI to close a PDA is a major risk factor for developing CLD in ELBW infants.

High-dose ibuprofen for patent ductus arteriosus in extremely preterm infants: a randomized controlled study

Our aim was to assess the hypothesis that a high-dose regimen of ibuprofen is more effective than the standard-dose regimen in closing patent ductus arteriosus (PDA) without increasing adverse effects. Infants of gestational age <29 weeks, with respiratory distress syndrome (RDS) and echocardiographic evidence of significant PDA at 12-24 h of life, were randomized to receive a standard (10-5-5 mg/kg/day) or high-dose (20-10-10 mg/kg/day) course of ibuprofen. We studied 70 infants, 35 of whom received the standard dose of ibuprofen and the other 35 the high dose. Of the infants treated with the standard-dose regimen, 37% had persistent PDA as compared with 14% of those treated with the high-dose regimen (P = 0.03). No differences in the occurrence of adverse effects were observed between the two groups. The high-dose ibuprofen regimen is more effective than the standard-dose regimen in closing PDA in preterm infants <29 weeks of gestation without increasing the adverse effect rate.

Comparison of renal effects of ibuprofen versus indomethacin during treatment of patent ductus arteriosus in contiguous historical cohorts

Background

Ibuprofen treatment of patent ductus arteriosus (PDA) has been shown to be as effective as indomethacin in small randomized controlled trials, with possibly fewer adverse effects. However, adverse renal effects of ibuprofen have been noted in some trials and suspected in our practice.

The purpose of this study was to examine whether ibuprofen and indomethacin treatment of PDA have comparable effects on renal function as evidenced by urine output and serum creatinine.

Methods

Retrospective chart review of 350 patients. Serum creatinine and urine output were recorded prior to start of treatment, during each course and after the last course of treatment. Pre-treatment mean creatinine and urine output values were compared to treatment and post treatment means using 2-factor repeated measures ANOVA.

Results

165 patients were treated with indomethacin (2005-2006) and 185 received ibuprofen (2007-2008). There was no difference between treatment groups in demographics or baseline renal function. For both groups, the number of treatment courses was inversely correlated with birth weight and gestational age. Analysis of the first course including all patients, revealed significant increase in creatinine and decrease in urine output with both drugs, with a more pronounced effect of indomethacin on creatinine. In the subgroup of 219 patients who received only one treatment course, there was a significant increase in creatinine after indomethacin, but not after ibuprofen. In the 131 who received 2 or more courses, the decrease in urine output and increase in creatinine were not different between drugs. There were significant decreases in urine output observed in the second and third courses of ibuprofen treatment (both by 0.9 mL/kg/hr).

Conclusion

Both drugs have a similar short-term effect on renal function. Indomethacin had a more prominent initial effect, while ibuprofen decreased renal function during the second and third courses similarly to indomethacin. The changes in renal function seen with ibuprofen treatment should be considered in fluid and electrolyte management, especially if treatment beyond one course is required.

Should we definitively abandon prophylaxis for patent ductus arteriosus in preterm new-borns?

Although the prophylactic administration of indomethacin in extremely low-birth weight infants reduces the frequency of patent ductus arteriosus and severe intraventricular hemorrhage, it does not appear to provide any long-term benefit in terms of survival without neurosensory and cognitive outcomes. Considering the increased drug-induced reduction in renal, intestinal, and cerebral blood flow, the use of prophylaxis cannot be routinely recommended in preterm neonates. However, a better understanding of the genetic background of each infant may allow for individualized prophylaxis using NSAIDs and metabolomics.

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.

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.