Diagnosis of patent ductus arteriosus

Prophylaxis of Patent Ductus Arteriosus with Paracetamol in Extremely Low Gestational Age Newborns (ELGANs): A Single-Institution Observational Study in Vietnam

INTRODUCTION

Prophylactic paracetamol for extremely low gestation age neonates (ELGAN, <27 weeks' gestation) with symptomatic patent ductus arteriosus (sPDA) in high-income countries (HIC) reduces medical and surgical interventions. Its effectiveness in low-to-middle-income countries (LMIC) remains uncertain. This study assesses prophylactic paracetamol's impact on sPDA interventions in ELGANs in an LMIC.

METHODS

This is a retrospective cohort study that compared a historical cohort of ELGANs that were treated with oral ibuprofen or intravenous paracetamol after diagnosis of sPDA (n = 104) with infants (n = 76) treated with prophylactic paracetamol (20 mg/kg loading, 7.5 mg/kg qid for 4 days), in a tertiary neonatal intensive care unit (NICU) in Vietnam. Oral ibuprofen or intravenous therapeutic paracetamol were administered if prophylactic paracetamol failed to close sPDA. Surgical ligation was conducted if targeted medical intervention failed, or the infant deteriorated from conditions attributable to sPDA.

RESULTS

In the historical cohort, 57 (55%) infants died within 7 days of life compared to 18 (24%) from the prophylactic cohort (p < 0.01). Of the survivors, 21 (45%) of the historical and 23 (39.7%) of the prophylactic cohort required surgical ligation (p = 0.6). Duration of hospitalization for survivors was lower in the prophylactic cohort (mean 74 vs. 97 days, p = 0.01). In the prophylactic cohort, 24 (41%) infants did not need further treatment while 34 (59%) required further treatment including ibuprofen and/or paracetamol 28 (48%) and surgical ligation 22 (38%).

CONCLUSIONS

Prophylactic paracetamol for ELGAN in LMIC does not reduce the need for surgical ligation, sPDA rates, and other PDA-related morbidities in infants who survive beyond 7 days of age. It may reduce the risk of death and the duration of hospitalization but further study into the reasons behind this need to be determined with larger studies.

A Network Meta-Analysis of Intravenous Versus Oral Acetaminophen for Patent Ductus Arteriosus

The use of acetaminophen to close a PDA in preterm infants is increasing; however, the most effective route of administration is not yet known. This network meta-analysis compares the efficacy of IV versus PO routes of acetaminophen administration on clinical outcomes related to the presence of a PDA in preterm neonates. Medline, Embase, Cochrane Central Register of Controlled Trials, Embase, Web of Science, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform were searched from inception to October 2020. A total 21 randomized controlled trials in neonates less than 37 weeks at birth, comparing oral or intravenously administered acetaminophen to close a PDA based on study criteria were included. Two authors extracted data independently and in duplicate. All outcomes were binary, and a frequentist network meta-analysis was performed. After one or two courses, both PO and IV acetaminophen were efficacious in closing a PDA with oral ranking higher than IV (low confidence). Neither medication was better than no treatment for secondary outcomes of NEC or BPD (moderate and low confidence respectively). We did not test the rectal route of acetaminophen administration and cannot make generalized statements. This study suggests oral acetaminophen increases the odds of being able to close a PDA in preterm neonates when compared to IV acetaminophen.

Relationship of Patent Ductus Arteriosus Echocardiographic Markers With Descending Aorta Diastolic Flow

OBJECTIVES

To characterize the relationship of echocardiographic markers of left heart overload and flow in peripheral major end-organ vessels (eg, celiac artery) with the presence of reversed holodiastolic flow in the descending aorta, considered a surrogate marker of an increased transductal shunt volume, in preterm patients with a patent ductus arteriosus (PDA).

METHODS

This work was a retrospective study of data from echocardiography performed to investigate the hemodynamic significance of a PDA in preterm patients. We studied differences in echocardiographic markers of the PDA shunt volume according to patterns of flow in the postductal descending aorta (no PDA, PDA with antegrade diastolic flow, and PDA with reversed diastolic flow). The strength of the association between each echocardiographic marker and the presence of aortic holodiastolic flow reversal was investigated.

RESULTS

We studied 137 patients with a median (interquartile range) birth weight of 850 (694-1030) g and a median gestational age of 25 (24-27) weeks. Among patients with a PDA (113), those with diastolic flow reversal in the descending aorta (44) presented had increased echocardiographic markers representative of the shunt volume (increased left ventricular output, left atrial-to-aortic ratio, pulmonary vein D wave, and shorter isovolumic relaxation time) compared to those with aortic antegrade diastolic flow. A positive, albeit weak, correlation between diastolic flow reversal and shunt volume echocardiographic markers was found. Abnormal diastolic flow in the celiac artery had the strongest correlation (R²  = 0.24).

CONCLUSIONS

In preterm patients with a PDA, echocardiographic markers of the shunt volume were more abnormal in patients with reversed diastolic flow in the descending aorta. These data support the assumption that variance in these markers are related to the shunt volume, which needs consideration when adjudicating hemodynamic significance.

A randomized trial of intravenous acetaminophen versus indomethacin for treatment of hemodynamically significant PDAs in VLBW infants

Objective was to compare the rate of successful treatment of hsPDA based on echocardiogram criteria after use of IV acetaminophen or IV indomethacin in very low-birthweight infants. The study was a multi-center, randomized controlled trial. Infants born prior to 32 weeks with birthweight ≤ 1500 g were included if PDA treatment was indicated within the 21 days after birth. hsPDA was defined by strict echocardiogram criteria. Eligible infants were randomized to treatment with either IV acetaminophen or IV indomethacin. Of 86 eligible infants, 17 infants were randomized to acetaminophen and 20 to indomethacin. One (5.9%) hsPDA in the acetaminophen group had successful treatment compared to 11 (55%) in the indomethacin group (p = 0.002). Eight (47%) in the acetaminophen group and 3 (15%) in the indomethacin group received transcatheter PDA closure (p = 0.07). IV indomethacin was more effective than IV acetaminophen for treatment of hsPDAs. More infants in the acetaminophen group received transcatheter closure.

Oral indomethacin versus oral ibuprofen for treatment of patent ductus arteriosus: a randomised controlled study in very low-birthweight infants

BACKGROUND

In low- and middle-income countries (LMIC), haemodynamically significant patent ductus arteriosus (hsPDA) is treated with oral indomethacin (IDC) and ibuprofen (IB) instead of intravenous formulations. No significant differences in efficacy have been reported. However, previous studies had small numbers of VLBW infants (<1500 g).

OBJECTIVE

To evaluate the efficacy of oral IDC and IB for closing PDA in VLBW infants with a gestational age of 24-32 weeks.

METHODS

This randomised controlled study enrolled 32 infants with hsPDA for treatment with either three doses of oral IDC or oral IB. Echocardiography was performed before and after treatment.

RESULTS

Oral IDC was more effective than oral IB (65% vs. 27%, p = 0.03). This difference was attributable to the subset of extremely low-birthweight infants (<1000 g) in whom an hsPDA closed 78% of the time after oral IDC compared with 13% of those treated with oral IB (p = 0.01). In contrast, there was no difference in hsPDA closure rates between the study groups of infants with birthweights of 1000-1499 g. There was no significant difference between the drugs in clinical and laboratory measures of adverse effects, nor of other clinical outcomes Conclusion: Oral IDC was more effective than oral IB for closing PDA in VLBW infants, without significant differences in side-effects or short-term outcomes.

Efficacy and safety of oral paracetamol versus oral ibuprofen for closure of patent ductus arteriosus in preterm infants: a randomized controlled trial

Objective: The objective of this study is to evaluate the efficacy and safety of oral paracetamol versus oral ibuprofen in the treatment of hemodynamically significant patent ductus arteriosus (hsPDA) in preterm infants. Study design: An interventional randomized case-control study, registered in ClinicalTrials.gov (NCT03265782), was conducted on 60 preterm infants with gestational age ≤34 weeks, postnatal age of 2-7 d and color Doppler echocardiographic evidence of hsPDA. Neonates were randomly assigned to two groups: 30 received oral ibuprofen and 30 received oral paracetamol. With failure of ductal closure, a second course of ibuprofen or paracetamol was given. The included newborns were subjected to detailed history, clinical examination, laboratory investigations that included complete blood count, renal, and liver function tests and echocardiographic evaluation. Results: Oral paracetamol was as effective as ibuprofen for the closure of patent ductus arteriosus (PDA) with one course of treatment (p > .05). Moreover, oral paracetamol was superior to ibuprofen among neonates who needed second course of treatment with significant decrease in end diastolic flow velocity in the left pulmonary artery (0.35 ± 0.09 versus 0.19 ± 0.06, p = .014), right ventricular systolic pressure (40.50 ± 12.91 versus 20.50 ± 0.58, p = .016) and left atrium to aortic root ratio (1.23 ± 0.14 versus 1.07 ± 0.04, p = .046) when compared to ibuprofen group. Furthermore, the mean difference between pre- and post-treatment PDA size was significantly higher in the paracetamol group compared with ibuprofen group after the second course of treatment (1.07 ± 0.32 versus 0.73 ± 0.38, p = .024). Oral paracetamol was comparable with ibuprofen in terms of the rate of non-surgical ductal closure [28 (93.3%) versus 24 (80%), p = .591]. In addition, oral paracetamol was as safe as oral ibuprofen in terms of gastrointestinal perforation or bleeding, necrotizing enterocolitis, bronchopulmonary dysplasia, intraventricular hemorrhage, thrombocytopenia, hepatic or renal dysfunction. Conclusions: Oral paracetamol is an effective and well-tolerated first-line drug treatment for PDA in premature infants.

[Clinical efficacy of pulmonary surfactant combined with budesonide for preventing bronchopulmonary dysplasia in very low birth weight infants]

OBJECTIVE

To explore the clinical efficacy of intratracheal instillation of pulmonary surfactant (PS) combined with budesonide for preventing bronchopulmonary dysplasia (BPD) in very low birth weight (VLBW) infants.

METHODS

Thirty VLBW infants with gestational age <32 weeks who developed neonatal respiratory distress syndrome (NRDS) (grade III-IV) suffering from intrauterine infection were randomly assigned into a PS + budesonide group and a PS alone group. The changes were compared between the two groups in arterial blood gas indexes, oxygenation index (OI), duration of mechanical ventilation, duration of oxygen supplementation, incidence of BPD, mortality rate at 36 weeks corrected gestational age and incidences of other complications except BPD.

RESULTS

Compared with the PS alone group, the PS+budesonide group had a lower incidence of BPD, shorter duration of mechanical ventilation and oxygen supplementation (P<0.05). On the 2nd to 6th day after treatment, the PS+budesonide group had higher pH value of arterial blood gas and OI and lower carbon dioxide partial pressure compared with the PS alone group (P<0.05). There were no significant differences in the mortality rate at 36 weeks corrected gestational age and the incidences of other complications except BPD between the two groups (P>0.05).

CONCLUSIONS

Intratracheal instillation of PS combined with budesonide can effectively reduce the incidence of BPD in VLBW premature infants with severe NRDS.

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.

A mitochondrial redox oxygen sensor in the pulmonary vasculature and ductus arteriosus

The mammalian homeostatic oxygen sensing system (HOSS) initiates changes in vascular tone, respiration, and neurosecretion that optimize oxygen uptake and tissue oxygen delivery within seconds of detecting altered environmental or arterial PO2. The HOSS includes carotid body type 1 cells, adrenomedullary cells, neuroepithelial bodies, and smooth muscle cells (SMCs) in pulmonary arteries (PAs), ductus arteriosus (DA), and fetoplacental arteries. Hypoxic pulmonary vasoconstriction (HPV) optimizes ventilation-perfusion matching. In utero, HPV diverts placentally oxygenated blood from the non-ventilated lung through the DA. At birth, increased alveolar and arterial oxygen tension dilates the pulmonary vasculature and constricts the DA, respectively, thereby transitioning the newborn to an air-breathing organism. Though modulated by endothelial-derived relaxing and constricting factors, O2 sensing is intrinsic to PASMCs and DASMCs. Within the SMC's dynamic mitochondrial network, changes in PO2 alter the reduction-oxidation state of redox couples (NAD(+)/NADH, NADP(+)/NADPH) and the production of reactive oxygen species, ROS (e.g., H2O2), by complexes I and III of the electron transport chain (ETC). ROS and redox couples regulate ion channels, transporters, and enzymes, changing intracellular calcium [Ca(2+)]i and calcium sensitivity and eliciting homeostatic responses to hypoxia. In PASMCs, hypoxia inhibits ROS production and reduces redox couples, thereby inhibiting O2-sensitive voltage-gated potassium (Kv) channels, depolarizing the plasma membrane, activating voltage-gated calcium channels (CaL), increasing [Ca(2+)]i, and causing vasoconstriction. In DASMCs, elevated PO2 causes mitochondrial fission, increasing ETC complex I activity and ROS production. The DASMC's downstream response to elevated PO2 (Kv channel inhibition, CaL activation, increased [Ca(2+)]i, and rho kinase activation) is similar to the PASMC's hypoxic response. Impaired O2 sensing contributes to human diseases, including pulmonary arterial hypertension and patent DA.

Peak systolic to end diastolic flow velocity ratio is associated with ductal patency in infants below 32 weeks of gestation

BACKGROUND

Early diagnosis and effective treatment of the patent ductus arteriosus (PDA) in infants less than 32 weeks gestation remains contentious.

OBJECTIVE

To determine which clinical and echocardiographic parameters are associated with PDA patency in preterm infants less than 32 weeks gestation.

DESIGN/METHODS

This was a prospective cohort study. An echocardiography (echo) was performed within 12-48 h of birth and a follow-up echo at 1 month of life. Parental consent was obtained.

RESULTS

55 babies were enrolled. Median (range) gestation was 28 (24-31) weeks and birth weight 1090 g (470-1800 g). ECHO 1 demonstrated that 50 babies had a PDA present within 48 h of birth, of which 19 were large (≥2 mm) (36%) and 31 were small (59%) on colour Doppler assessment of duct diameter. Three babies died before 1 month. At 1 month 30 babies still had a PDA (58%), 10 of which were large (19%) and 19 were small (36%). Parameters significantly associated with large PDAs versus no PDA at 1 month were gestational age (26 weeks vs 30 weeks, p=0.002), birth weight (860 g vs 1290 g, p=0.007) and ventilator support at 48 h (80% vs 17%, p=0.001). Echo parameters revealed that ductal size on colour Doppler (2.5 mm vs 1.5 mm, p=0.003), end diastolic flow velocity (57 m/s vs 147 m/s, p<0.001) and peak systolic to end diastolic flow velocity ratio (2.29 vs 1.23, p=0.001) at 48 h were associated with large PDAs at 1 month.

CONCLUSIONS

For infants less than 32 weeks gestation a peak systolic to end diastolic flow velocity ratio>2 within 48 h of birth is associated with a persistent large PDA at 1 month of age.

Development of left ventricular longitudinal speckle tracking echocardiography in very low birth weight infants with and without bronchopulmonary dysplasia during the neonatal period

Objectives

In preterm infants, postnatal myocardial adaptation may be complicated by bronchopulmonary dysplasia (BPD). We aimed to describe the development of left ventricular function by serial 2D, Doppler, and speckle tracking echocardiography (2D-STE) in infants with and without BPD during the neonatal period and compare these to anthropometric and conventional hemodynamic parameters.

Study Design

Prospective echocardiography on day of life (DOL) 1, 7, 14, and 28 in 119 preterm infants <1500 g birth weight of whom 36 developed BPD (need for oxygen supplementation at 36 weeks gestational age). Non-BPD and BPD infants differed significantly in median (IQR) gestational age (25.5(24–26.5) weeks vs. 29(27–30) weeks, p<0.001) and birth weight (661(552–871) g vs. 1100(890–1290) g, p<0.001).

Results

The intra- and inter-observer variability of the 2D-STE parameters measured did not depend on time of measurement, although there were significant differences in the reproducibility of the parameters. Low intra- and inter-observer variability was seen for longitudinal systolic strain and strain rate mid septum with a median CV (coefficient of variation) of <4.6%. Much higher CVs (>10%) were seen for the apical segment. While anthropometric parameters show rapid development during the first 4 weeks of life, the speckle tracking parameters did not differ statistically significantly during the neonatal period. Infants with and without BPD differed significantly (p<0.001) in the development of anthropometric parameters, conventional hemodynamic parameters except for heart rate, and 2D-STE parameters: global longitudinal systolic strain rate (GLSSR) and longitudinal systolic strain for the mid left wall (LSSR). The largest differences were seen at DOL 1 and 7 in GLSSR (p<0.001) and in LSSR (p<0.01).

Conclusions

Reproducible 2D-STE measurements are possible in preterm infants <1500 g. Cardiac deformation reveals early (DOL 1 and 7) ventricular changes (GLSSR and LSSR) in very low birth weight infants who develop BPD.

"Shunt index" can be used to predict clinically significant patent ductus arteriosus in premature neonates in early post-natal life

BACKGROUND

This study aimed to examine the differences between arterial and inferior caval vein oxygen saturation, fractional oxygen extraction, and the shunt index, which were calculated in the diagnosis of patent ductus arteriosus.

METHODS

Twenty-seven preterm infants were included in this study and were divided into two groups according to patent ductus arteriosus. Among them, 11 (41%) infants had haemodynamically significant patent ductus arteriosus and 16 (59%) did not have significant patent ductus arteriosus. Synchronous arterial and venous blood gases were measured during the first post-natal hours after the insertion of umbilical catheters. The differences between arterial and inferior caval vein oxygen saturation, inferior body fractional oxygen extraction, and the shunt index were calculated. Echocardiography was performed before the 72nd hour of life in a selected group of patients who had haemodynamically significant patent ductus arteriosus. Ibuprofen treatment was administered to patients with patent ductus arteriosus. Echocardiography was performed on the 72nd hour of life in preterm infants without any clinical suspicion of patent ductus arteriosus.

RESULTS

The early measured differences between arterial and inferior caval vein oxygen saturation and inferior body fractional oxygen extraction were found to be lower and the shunt index was found to be higher in the haemodynamically significant patent ductus arteriosus group than in the group without haemodynamically significant patent ductus arteriosus.

CONCLUSION

We found that the shunt index, calculated in the first hours of life as ≥63%, predicted haemodynamically significant patent ductus arteriosus with a sensitivity of 78% and specificity of 82% in preterm newborns.

Assessment of PDA shunt and systemic blood flow in newborns using cardiac MRI

Patent ductus arteriosus (PDA) remains common in preterm newborns, but uncertainty over optimal management is perpetuated by clinicians' inability to quantify its true haemodynamic impact. Our aim was to develop a technique to quantify ductal shunt volume and the effect of PDA on systemic blood flow volume in neonates. Phase contrast MRI sequences were optimized to quantify left ventricular output (LVO) and blood flow in the distal superior vena cava (SVC) (below the azygos vein insertion), descending aorta (DAo) and azygos vein. Total systemic flow was measured as SVC + DAo-azygos flow. Echo measures were included and correlated to shunt volumes. 75 infants with median (range) corrected gestation 33(+6) (26(+4) -38(+6) ) weeks were assessed. PDA was present in 15. In 60 infants without PDA, LVO matched total systemic flow (mean difference 2.06 ml/kg/min, repeatability index 13.2%). In PDA infants, ductal shunt volume was 7.9-74.2% of LVO. Multiple linear regression analysis correcting for gestational age showed that there was a significant association between ductal shunt volume and decreased upper and lower body flow (p = 0.01 and p < 0.001). However, upper body blood flow volumes were within the control group 95% confidence limits in all 15 infants with PDA, and lower body flow volumes within the control group limits in 12 infants with PDA. Echocardiographic assessment of reversed diastolic flow in the descending aorta had the strongest correlation with ductal shunt volume. We have demonstrated that quantification of shunt volume is feasible in neonates. In the presence of high volume ductal shunting the upper and lower body flow volume are somewhat reduced, but levels remain within or close to the normal range for preterm infants.

Patent ductus arteriosus in preterm infants is associated with cardiac autonomic alteration and predominant parasympathetic stimulation

BACKGROUND

Hemodynamic disorders in patent ductus arteriosus (PDA) may alter the stimulation of the autonomic nervous system.

AIM

The objective of this study was to analyze the orthosympathetic-parasympathetic balance in preterm infants with PDA.

STUDY DESIGN AND SUBJECTS

Patients were included from consecutive admissions to Amiens University Hospital from 2009 to 2011. We defined a PDA group and a Control group (echographic criteria). For each patient, three 4-minutes segments of ECG were recorded during quiet sleep and the RR chronologic series were extracted, and spectral (Fourier Transform) and time-domain analyses were performed. For each parameter of heart rate variability (HRV), average of three measures was determined and analysed.

RESULTS

Forty-four patients were included for analysis. The total HRV power, LF/HF ratio and SDNN were lower in the PDA group (n = 22, gestational age 28.2 w ± 1.9) than in the Control group (n = 22, gestational age 28.8 w ± 2). The decrease in LF power destabilized the autonomic balance in favour of parasympathetic stimulation. After adjustment for postconceptional age, PDA was still associated with parameters of autonomic neural stimulation.

CONCLUSION

These results suggest association of PDA with predominance of parasympathetic stimulation in preterm infants. The mechanisms of homeostasis in patients with PDA are very complex and involve both circulatory adaptations and control by autonomic pathway. If confirmed, our results could be interesting for future researches aiming to verify the interest of new targeted therapies for the management of PDA.

Neonatal outcome of preterm infants born to mothers with abnormal genital tract colonisation and chorioamnionitis: a cohort study

PURPOSE

We hypothesised that abnormal genital tract colonisation leading to an in utero inflammation/infection process, contributes to the risk of respiratory distress syndrome (RDS), patent ductus arteriosus (PDA), intra ventricular haemorrhage (IVH), bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP) and necrotizing enterocolitis (NEC) in preterm infants.

METHODS

396 placentas and umbilical cords of neonates born at 22-32weeks of gestation were evaluated. Genital tract and amniotic fluid swabs were cultured for aerobic and anaerobic bacteria.

RESULTS

Chorioamnionitis significantly increases the risk for RDS (OR 1.74, 95% CI 1.14-2.65), NEC (OR 3.22, 95% CI 1.36-3.28) and ROP>2 (OR 2.12, 95% CI 1.33-3.36). But the risk for IVH, PDA and BPD did not differ between the groups. Klebsiella pneumoniae (OR 5.33, 95% CI 1.06-26.79), Staphylococcus sp. (OR 18.39, 95% CI 2.32-145.2) and Enterococcus faecalis (OR 10.7, 95% CI 1.27-89.9) showed a significant relationship with intrauterine inflammation processes. E. faecalis increased the risk for NEC (OR 6.13, 95% CI 1.059-37.6). We did not note a link between ROP and genital tract colonisation. Interestingly PDA seems to be triggered by the presence of Pseudomonas aeruginosa (OR 2.38 95% CI 1.83-3.82).

CONCLUSION

Our results show a link between K. pneumoniae, Staphylococcus sp., E. faecalis and intrauterine infection. E. faecalis increases the risk for NEC, and suggests a direct link between gram + bacteria, chorioamnionitis and NEC.

Urinary NT-proBNP and ductal closure in preterm infants

OBJECTIVE

To explore the association of urinary N-terminal pro-brain natriuretic peptide (NT-proBNP) concentrations and closure of patent ductus arteriosus (PDA) in preterm infants.

STUDY DESIGN

Blinded prospective study involving 136 preterm infants (median (interquartile range) gestational age 28 (26 to 30) weeks; birth weight 1030 (780 to 1270) g). NT-proBNP was determined in urine collected on day of life (DOL) 2, 7, 14 and 28.

RESULT

Urinary NT-proBNP/creatinine ratios declined continuously between DOL 2 (74 (17 to 248) μg g(-1)) and DOL 28 (4 (2 to 12) μg g(-1)) and were significantly elevated in ventilated infants on DOL 2, 7 and 14, and in ventilated infants with a hemodynamically significant PDA on DOL 2. Furthermore, urinary NT-proBNP/creatinine ratios on day 14 were higher in 14 ventilated infants who did not respond to pharmacological treatment and subsequently required surgical PDA closure (247 (214 to 547) μg g(-1)) than in ventilated infants (n=7) with successful pharmacological PDA closure (55 (21 to 114) μg g(-1); P<0.05). A cutoff >210 μg g(-1) on day 14 had a sensitivity of 75% and specificity of 100% for predicting non-responsiveness to pharmacological treatment.

CONCLUSION

Measurement of urinary NT-proBNP is a new and simple non-invasive test for preterm infants, which may be helpful in guiding PDA treatment decisions.

Intravenous paracetamol treatment in the management of patent ductus arteriosus in extremely low birth weight infants

BACKGROUND

Treatment options for the closure of a hemodynamically significant patent ductus arteriosus (hsPDA) include medical therapy such as ibuprofen and indomethacin and surgical ligation.

OBJECTIVE

To evaluate the efficacy of intravenous paracetamol in preterm infants with hsPDA whose feeding was contraindicated or had feeding intolerance.

METHODS

Preterm infants with hsPDA were started on intravenous paracetamol treatment with parental consent. Paracetamol was administered at a dose of 60 mg/kg/day, in four divided doses, for a period of 3 days. In the absence of closure of hsPDA, treatment was extended up to 6 days, after which echocardiographic examination was performed.

RESULTS

A total of 10 preterm infants were included in the study with a median gestational age of 27(4/7) weeks (minimum-maximum: 24-29) and a median birth weight of 775 g (590-990). The first dose of intravenous paracetamol was given after a median of 6 days (2-15). On echocardiographic examination, median internal ductal diameter was 2 mm (1.5-3), with a median left atrium-to-aortic root ratio of 1.95 (1.6-2.2). Intravenous paracetamol resulted in successful closure of hsPDA in all patients.

CONCLUSIONS

This study is the first case series in the literature which used intravenous paracetamol treatment for hsPDA. We believe that intravenous paracetamol could be used as an alternative drug for infants. Further prospective randomized-controlled trials are needed to evaluate the efficacy of intravenous paracetamol for the closure of hsPDA.

B-type natriuretic Peptide assay for the diagnosis and prognosis of patent ductus arteriosus in preterm infants

BACKGROUND AND OBJECTIVES

Patent ductus arteriosus (PDA) is a significant cause of morbidity and mortality in preterm infants. Measurement of plasma B-type natriuretic peptide (BNP) has been reported to be a useful bedside screening tool for the presence of hemodynamically significant PDA (hsPDA) in neonates. This study was conducted to investigate the usefulness of a BNP assay as a biochemical marker for the diagnosis of hsPDA and predictive biomarker of the response to indomethacin in preterm infants.

SUBJECTS AND METHODS

Preterm infants born at <37 weeks' gestational age were prospectively enrolled within 24 hours of birth. Plasma BNP levels were measured on days 1, 4, and 7. Significant PDA was diagnosed by large ductal flow with left to right shunt on color Doppler echocardiography, along with clinical features of PDA. Following that, hsPDA was treated with indomethacin.

RESULTS

A total of 28 preterm infants were prospectively enrolled in this study. Seven infants with PDA had higher on day 4 plasma BNP values (median 654.68 pg/mL; range 428.29-1280.00) compared to the control group (median 124.52 pg/mL; range 37.21-290.49). The area under the receiver operator characteristic curve for the detection of hsPDA was high: 0.998 (95% confidence interval: 0.995-1.002). The cutoff of BNP concentration for the diagnosis of hsPDA was determined to be 412 pg/mL (sensitivity: 100%; specificity: 95%).

CONCLUSION

B-type natriuretic peptide can be a useful biomarker for the screening and diagnosis of PDA in preterm infants. Serial BNP measurements are valuable for assessing the clinical course and indomethacin responsiveness of PDA.

Cardiac troponin T and illness severity in the very-low-birth-weight infant

Introduction. Respiratory distress are very common in Very-low-birth-weight (VLBW) infants and Myocardial injury may play a role in the disease outcome. Cardiac troponin T (cTnT) is the most useful marker of injury in adult population, but has not been extensively studied in this population. Aim. To study the role of cTnT in VLBW infants and its association with clinical outcomes. Methods. All VLBW infants admitted to our NICU were included in the study. Echocardiography and blood samples for cTnT determination were collected at 24 and 48 hours of life, and values >0.1 ng/mL were considered CTnT-positive values. Results. A total of 116 neonates had their blood samples collected. The median cTnT concentration within 24 hours was 0.191 (0.1-0.79) ng/mL and within 48 hours was 0.293 (0.1-1.0) ng/mL. A logistic regression analysis showed that PDA, low GA, and use of dopamine were independently associated with positive cTnT and abnormal Dopplerfluxometry and diuretics use had protective effects and was independently associated with troponin values. Conclusion. We observed a high prevalence of positivecTnT values in VLBW infants associated with illness severity. Our findings suggest that cTnT may be a useful and early marker of myocardial injury in VLBW infants.

The methodology of Doppler-derived central blood flow measurements in newborn infants

Central blood flow (CBF) measurements are measurements in and around the heart. It incorporates cardiac output, but also measurements of cardiac input and assessment of intra- and extracardiac shunts. CBF can be measured in the central circulation as right or left ventricular output (RVO or LVO) and/or as cardiac input measured at the superior vena cava (SVC flow). Assessment of shunts incorporates evaluation of the ductus arteriosus and the foramen ovale. This paper describes the methodology of CBF measurements in newborn infants. It provides a brief overview of the evolution of Doppler ultrasound blood flow measurements, basic principles of Doppler ultrasound, and an overview of all used methodology in the literature. A general guide for interpretation and normal values with suggested cutoffs of CBFs are provided for clinical use.

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.

Change in blood pressure and pulse pressure in preterm infants after treatment of patent ductus arteriosus with indomethacin

Background and Objectives

Patent ductus arteriosus (PDA) is associated with increased morbidity and mortality in premature infants. Therefore, an early diagnosis and treatment of a hemodynamically significant PDA are very important. A widened pulse pressure is considered to be a well known clinical sign of a PDA in older infants and children; however, whether this is also applicable in the case of preterm infants remains to be confirmed. The aims of this study were to investigate the change in blood pressure (BP) before and after medical treatment of a PDA with indomethacin and to evaluate if the change in the pulse pressure in preterm infants with a medically treated PDA could be used as a reliable clinical predictor of a hemodynamically significant PDA.

Subjects and Methods

Between January 2005 and June 2009, a retrospective analysis was performed in preterm infants with a hemodynamically significant PDA (PDA group, n=72) and preterm infants without a PDA (control group, n=72) at the Chonnam National University Hospital Neonatal Intensive Care Unit. The PDA was closed by treatment with indomethacin. The BP was compared between the two groups over the seven days after the first dose of indomethacin.

Results

In preterm infants with a hemodynamically significant PDA, the mean systolic (55.1±6.0 mmHg) and diastolic BPs (31.4±6.2 mmHg) were lower than those in the controls (mean systolic BP 58.0±6.4 mmHg, mean diastolic BP 34.7±6.0 mmHg) before indomethacin treatment. When the ductus arteriosus was successfully closed by indomethacin treatment, there was a gradual increase in both the systolic and diastolic BPs without any change in the pulse pressure.

Conclusion

The results of this study show that a widened pulse pressure is not a useful clinical sign of a hemodynamically significant PDA in preterm infants. However, low systolic and diastolic BPs may be useful clinical signs of a hemodynamically significant PDA in preterm infants. If the systolic and diastolic BP is low, a PDA should be considered and echocardiography should be performed for early diagnosis and treatment.

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.

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.

Humanistic therapies versus other psychological therapies for depression

This is the protocol for a review and there is no abstract. The objectives are as follows: To examine the effectiveness and acceptability of all humanistic therapies compared with all other psychological therapy approaches for acute depression.To examine the effectiveness and acceptability of different humanistic therapy models (person-centred, gestalt, process-experiential, transactional analysis, existential and non-directive therapies) compared with all other psychological therapy approaches for acute depression.To examine the effectiveness and acceptability of all humanistic therapies compared with different psychological therapy approaches (psychodynamic, behavioural, humanistic, integrative, cognitive-behavioural) for acute depression.

Role of echocardiography on the evaluation of patent ductus arteriosus in newborns

The echocardiogram is the preferred procedure in confirming the diagnosis and characterizing PDA. Doppler echocardiography proved more efficient than clinical examination in grading PDA and becomes essential in the evaluation of clinically significant ductal shunting. Four patterns of PDA shunt can be identified using pulsed Doppler echocardiography: pulmonary hypertension, growing pattern, pulsatile pattern, closing pattern. In this review we confirm that echocardiography can provide a reasonable as well as accurate prediction of the development of later clinically significant PDA by a combination of variables that are easy to measure and compare.

Effect of aerosolized PGE(1) on the ductus arteriosus of neonatal swine

BACKGROUND

Inhaled PGE(1) (IPGE(1)) is a potential pulmonary vasodilator in neonatal respiratory failure. However, its effect on the patency of the ductus arteriosus (DA) has not been described.

OBJECTIVE

To investigate the effect of IPGE(1) on the DA in healthy piglets.

DESIGN/METHODS

IPGE(1) (1200ng/kg/min) [Study] or nebulized saline [Control] was administered using a jet nebulizer. Transthoracic echocardiography (TTE) was performed prior to (T0) and after 24h of aerosol therapy (T24). The DA was also evaluated histomorphologically at autopsy.

RESULTS

Fifteen piglets, 1-9 days old (study=9; control=6), were evaluated for DA patency. Study piglets received IPGE(1) for 12-24h. TTE was performed on 12 piglets at T0. Nine animals showed no ductal flow and 3 (1 study, 2 control) had a small DA. TTE at T24 in 5 animals showed no change in DA. At autopsy, the ductal diameter and histologic maturity stage were comparable in study and control animals.

CONCLUSIONS

High dose IPGE(1) given for 12-24h does not exert significant effect on the DA of healthy term piglets as evaluated by echocardiography and histomorphology. We conclude that ductal patency in neonates is influenced not only by prostaglandins but also by factors like hypoxemia, prematurity, and heart disease.

Renal impairment associated with indomethacin treatment for patent ductus arteriosus in extremely preterm neonates—is postnatal age at start of treatment important?

OBJECTIVE

To study serum creatinine (SCr) levels following indomethacin for patent ductus arteriosus (PDA) closure in extremely preterm neonates in relation to postnatal age at the start of treatment.

METHODS

This was a retrospective (January 2000-December 2002) analysis of data on preterm neonates (gestation <29 weeks) who received indomethacin for PDA. Pre-existing renal malformation and/or impairment and high serum levels of nephrotoxic drugs were criteria for exclusion.

RESULTS

Indomethacin was commenced at postnatal age <7 days and >or=7 days in 60 (group 1) and 30 (group 2) neonates, respectively. The median (Q1, Q3) gestational age and birth weight for group 1 and group 2 neonates were 25 (23, 27) vs. 25 (24, 26) weeks and 740 (620, 909) vs. 780 (663, 966) grams, respectively. Postnatal age <7 days at start of indomethacin was associated with higher baseline (0.083 (0.074, 0.090) vs. 0.073 (0.054, 0.083) mmol/L, p=0.001) and peak SCr levels (0.099 (0.089,0.109) vs. 0.090 (0.064, 0.104) mmol/L, p=0.015). Logistic regression analysis controlling for gestational age and baseline SCr level indicated that postnatal age >or=7 days was a risk factor for elevated SCr after indomethacin (OR=13.4, 95% CI: 3.8-46.6, p < 0.001).

CONCLUSION

Postnatal age >or=7 days at the start of indomethacin is a predictor of a significant rise in SCr in extremely preterm neonates.

Clinical and echocardiographic diagnosis of patent ductus arteriosus in premature neonates

The ductus arteriosus frequently fails to close in premature neonates. Considerable difference in opinion exists around what signifies a hemodynamically significant patent ductus arteriosus (PDA) and how reliable clinical signs are in determining the degree of the left-to-right shunting. Although reliance on clinical signs alone could delay the diagnosis of a PDA, there is insufficient evidence to suggest that early treatment improves outcome. Echocardiography is often used as the gold standard for diagnosing a PDA. A combination of echocardiographic measurements may assist in the early diagnosis of a PDA with a hemodynamically significant degree of left-to-right shunting, especially in extremely premature babies, where closure can be significantly delayed. Decision to treat PDA should be based on a combination of clinical signs and echocardiographic parameters. Monitoring B-type natriuretic peptide may be useful in the diagnosing neonates with symptomatic PDA.

Does point-of-care functional echocardiography enhance cardiovascular care in the NICU?

Although the last two decades have seen major advances in the care of sick, extremely premature newborns, the approach to cardiovascular assessment and monitoring remains suboptimal owing to an overreliance on poorly predictive clinical markers such as heart rate or capillary refill time. Point-of-care functional echocardiography (PCFecho) enables real-time evaluation of cardiac performance and systemic hemodynamics to characterize acute physiology, identify the exact nature of cardiovascular compromise and guide therapeutic decisions. In this article, we will review four clinical scenarios where bedside functional cardiac imaging enabled delineation of the real clinical problem and refinement of the therapeutic care plan with direct patient benefits.

Does retrograde diastolic flow in the descending aorta signify impaired systemic perfusion in preterm infants?

High-volume systemic-to-pulmonary ductal shunting occurs frequently in preterm infants and is indicated by diastolic flow reversal in the descending aorta (DAo). We studied the relationship between ductal diameter, diastolic DAo reversal, and left ventricular output (LVO); and superior vena caval (SVC) flow (upper body perfusion) and DAo flow (lower body perfusion) in preterm (<31 wk) infants. Echocardiographic assessments were performed at 5, 12, 24, and 48 h postnatal age (80 infants, median gestation 28 wk, 1060 g). Incidence of ductal patency fell from 100% at 5 h to 72% at 48 h; incidence of pure systemic-to-pulmonary shunting increased from 66% to 95% of infants with patent ducts. In infants with duct diameter greater than the median, 35-48% of infants had DAo flow reversal. In infants with duct diameter greater than median, DAo reversal was associated with 23-29% increases in LVO at 5-48 h, and 35% decreases in DAo flow volume at 24-48 h, but no differences in SVC flow. In conclusion, a large duct with left-to-right shunting is common in preterm infants. Retrograde DAo flow is a marker of high-volume shunt, evidenced by increased LVO. Preterm infants with high-volume ductal shunt may have preserved upper body perfusion but reduced lower body perfusion.

Patent ductus arteriosus: an overview

Patent ductus arteriosus (PDA) is one of the most common congenital heart defects, accounting for 5%-10% of all congenital heart disease in term infants. The occurrence of PDA is inversely related to gestational age and weight, with an even greater incidence in preterm infants. The maintenance of ductal patency is essential for the normal development of the fetus. In the neonate, however, persistent patency of the ductus arteriosus (DA) is associated with significant morbidity and mortality. Normally, at birth, the DA constricts, resulting in intraluminal ischemic hypoxia, which eventually leads to closure and remodeling of the ductus. PDA in term infants is usually associated with a functional defect, whereas in preterm infants it is associated with immaturity. Normal physiologic mechanisms contributing to closure - oxygen tension and decreased prostaglandins-are altered in prematurity. Clinical signs of ductal patency include murmur, tachycardia, bounding peripheral pulses, and congestive heart failure and associated symptoms. Symptoms are not always present; therefore, diagnostic imaging is critical if a PDA is suspected on clinical grounds. Three management strategies are currently available for PDA: fluid restriction and diuretics (as clinically appropriate), medical intervention, and surgical ligation. Pharmacologic closure can be achieved via administration of intravenous indomethacin or ibuprofen lysine. While both agents have shown similar efficacy, ibuprofen lysine has demonstrated an improved safety profile, particularly in terms of renal effects, compared to indomethacin.

Patent ductus arteriosus: an overview

Patent ductus arteriosus (PDA) is one of the most common congenital heart defects, accounting for 5%-10% of all congenital heart disease in term infants. The occurrence of PDA is inversely related to gestational age and weight, with an even greater incidence in preterm infants. The maintenance of ductal patency is essential for the normal development of the fetus. In the neonate, however, persistent patency of the ductus arteriosus (DA) is associated with significant morbidity and mortality. Normally, at birth, the DA constricts, resulting in intraluminal ischemic hypoxia, which eventually leads to closure and remodeling of the ductus. PDA in term infants is usually associated with a functional defect, whereas in preterm infants it is associated with immaturity. Normal physiologic mechanisms contributing to closure - oxygen tension and decreased prostaglandins-are altered in prematurity. Clinical signs of ductal patency include murmur, tachycardia, bounding peripheral pulses, and congestive heart failure and associated symptoms. Symptoms are not always present; therefore, diagnostic imaging is critical if a PDA is suspected on clinical grounds. Three management strategies are currently available for PDA: fluid restriction and diuretics (as clinically appropriate), medical intervention, and surgical ligation. Pharmacologic closure can be achieved via administration of intravenous indomethacin or ibuprofen lysine. While both agents have shown similar efficacy, ibuprofen lysine has demonstrated an improved safety profile, particularly in terms of renal effects, compared to indomethacin.

Is refractory hypotension in preterm infants a manifestation of early ductal shunting?

BACKGROUND

Clinicians frequently use hydrocortisone (HC) to treat vasopressor-resistant hypotension even before establishing its cause.

OBJECTIVE

To identify the etiologic factors leading to development of refractory hypotension, and to assess if patent ductus arteriosus (PDA) is associated with refractory hypotension during the first week of life.

STUDY DESIGN

The medical records of 290 consecutively born infants <or=30 weeks' gestational age (GA) were reviewed to identify the escalating need for vasopressors to maintain mean arterial blood pressure (MABP) at or above a level equal to the GA in completed weeks. Refractory hypotension was defined as MABP unresponsive to fluid boluses and high-dose vasopressors (dopamine and dobutamine at doses 20 microg/kg/min each and/or epinephrine) prompting the use of HC.

RESULTS

Eighty-nine (30.7%) of 290 infants had refractory hypotension between postnatal days 2 and 7. Infants with refractory hypotension were more likely to have a lower birth weight and GA (P<0.001), been treated with surfactant (P=0.004) and received indomethacin for a symptomatic PDA (P<0.001). To identify the etiologic factors, a univariate analysis revealed that the use of high-frequency oscillatory ventilation, presence of air leaks, PDA, sepsis, hyperkalemia and intraventricular hemorrhage (IVH) were significantly associated with refractory hypotension. However, multivariate analysis confirmed the independent association of only PDA (odds ratio (OR) 7.6, 95% confidence interval (CI) 3.3-17.7, P=0.000), severe IVH (OR 2.6, 95% CI 1.1-6.4, P=0.03) and GA (OR 0.7, 95% CI 0.6-0.8, P=0.001).

CONCLUSIONS

Evaluation for early ductal shunting and closure of the ductus, if patent, should be attempted before HC is considered in hypotensive infants with escalating needs for vasopressors.

Management of the neonate with patent ductus arteriosus

Care of the preterm infant with a suspected or confirmed diagnosis of patent ductus arteriosus (PDA) is a frequent challenge for the neonatal nurse. Management of term infants with cardiac lesions dependent upon a PDA can be even more challenging. It is vital for neonatal nurses to understand the normal cardiovascular and pulmonary changes that occur at birth so they can anticipate pathological processes influencing the clinical course of an infant with a PDA. In addition, knowledge of current and effective treatment approaches is essential to providing optimal care for these vulnerable infants, as well as in guiding their parents. The purpose of this article is to review current information about PDA, including physiology, pathophysiology, pharmacological approaches, surgical considerations, complications and outcomes, parental support, and areas for future research.

Longitudinal changes of brain-type natriuretic peptide in preterm neonates

OBJECTIVE

To determine age-related concentrations of brain-type natriuretic peptide in preterm infants using bedside Triage brain-type natriuretic peptide test and correlate it to the presence or absence of the patent ductus arteriosus and ventilatory support.

METHODS

Serum brain-type natriuretic peptide levels were measured in infants who were born at <32 weeks' gestation from birth to 2 months of age. Serial echocardiograms were performed, until closure of the patent ductus arteriosus, or until discharge. Brain-type natriuretic peptide levels were correlated to the day of life, gestational age, presence or absence of the patent ductus arteriosus, and the degree of ventilatory support. Nineteen preterm infants (gestational age: 24-31 weeks; birth weight: 645-1670 g) were enrolled prospectively during the first 2 weeks of life. Serum brain-type natriuretic peptide levels (pg/mL) were determined in 177 blood samples, and 87 paired echocardiograms were performed.

RESULTS

Significant negative correlation was found between brain-type natriuretic peptide levels and the day of life and remained significant when the patients were stratified by gestational age (< or =28 weeks and >28 weeks). Higher brain-type natriuretic peptide levels correlated with increasing grade of the patent ductus arteriosus. Significant differences in brain-type natriuretic peptide levels were seen with increasing ventilatory support. Comparisons between the size of patent ductus arteriosus and the degree of ventilatory support to brain-type natriuretic peptide levels revealed that the size of the patent ductus arteriosus was the major determinant of both brain-type natriuretic peptide levels and the degree of ventilatory support.

CONCLUSIONS

Similar to term infants, brain-type natriuretic peptide levels of preterm infants are related to the chronological age and decline during the first month of life. Rapid bedside Triage brain-type natriuretic peptide is a potentially valuable and practical assay in determining the hemodynamic changes in preterm infants.

Role of plasma B-type natriuretic peptide in screening for hemodynamically significant patent ductus arteriosus in preterm neonates

BACKGROUND

B-type natriuretic peptide (BNP) is a hormone secreted by the ventricles under hemodynamic stress and congestive failure.

OBJECTIVE

The objective of the present study was to evaluate whether BNP can be used as a valid screening test for the presence of a hemodynamically significant patent ductus arteriosus (hsPDA) in the preterm neonate.

MATERIALS AND METHODS

This was a prospective blinded study involving preterm neonates with birth weights <or=1500 g and gestational age <or=34 weeks. Each enrolled neonate underwent the initial echocardiogram for a clinical suspicion of patent ductus arteriosus (PDA) and BNP assay within 3 hours of each other. Those neonates who did not have a PDA or who were not treated underwent a repeat echo and BNP measurement 48 to 72 hours after the first echo. In patients who received treatment for a PDA, an echo and BNP were repeated 48 to 72 hours after completion of treatment.

RESULTS

A total of 29 newborns with a median birth weight of 870 g (560 to 1325 g) and a median gestation of 26 weeks (24 to 31 weeks) were enrolled at a median age of 7 days (2 to 28 days). BNP levels were significantly higher in neonates with hsPDA (n=14) compared to those without (n=15) (508.5+/-618.2 vs 59.5+/-69.9 pg/ml, p<0.005). At a cutoff value of 70 pg/ml, BNP had a sensitivity of 92.9%, specificity of 73.3%, positive likelihood ratio of 3.5 and negative likelihood ratio of 0.09 for detection of hsPDA. BNP levels dropped significantly after medical or surgical closure of hsPDA (n=12), (404.9+/-159.2 to 25.1+/-4.1 pg/ml, p=0.03).

CONCLUSIONS

Elevation of plasma BNP accurately detects the presence of hsPDA in premature infants. Successful closure is reflected by a corresponding decrease in BNP. At a cutoff of 70 pg/ml, BNP is a useful screening tool for diagnosis and for monitoring efficacy of treatment of hsPDA.

Comparison of clinical criteria with echocardiographic findings in diagnosing PDA in preterm infants

OBJECTIVE

The purpose of our study was to compare clinical criteria with echocardiographic findings in diagnosing hemodynamically significant patent ductus arteriosus (PDA) in preterm infants.

METHODS

We evaluated 25 preterm infants born at 24-32 weeks of gestation with birth weight from 500 to 1700 g for tachycardia, heart murmur, hyperdynamic chest, presence of dorsalis pedis pulse, hypotension, and worsening of the respiratory status at 48-72 h of life. A pediatric cardiologist blinded to clinical findings performed the echocardiograms. Infants with congenital anomalies and conditions, sepsis, IVH, and necrotizing enterocolitis were excluded.

RESULTS

Out of 25 preterm infants, 12 infants had hemodynamically significant PDA with left-to-right shunt. Two infants had small PDA and in 11 infants the ductus arteriosus was not patent. PDA infants had lower gestational age (P = 0.02) and birth weight (P = 0.03). Their Apgar scores (1 min) were lower (P = 0.03). The heart rate between the two groups differed, but was clinically within normal limits. Systolic (P = 0.05) and mean blood pressures (P = 0.04) were lower in the PDA group. A poor association between heart murmur, hyperdynamic chest and dorsalis pedis pulse, and the presence of PDA was revealed.

CONCLUSION

Echocardiogram is required for early diagnosis of PDA in preterm infants, as clinical signs are not reliable in the first few days of life.

Is surgical ligation of patent ductus arteriosus necessary? The Western Australian experience of conservative management

BACKGROUND

Surgical ligation of patent ductus arteriosus (PDA) is widely practised in preterm infants despite no clear evidence that this improves outcomes. Geographical isolation meant that ductal ligation was not an option in King Edward Memorial Hospital until recently.

OBJECTIVE

A retrospective data analysis to test the hypothesis that outcomes of infants with persistent PDA were no worse than those of infants with no significant duct or a duct that closed after medical treatment.

PATIENTS AND METHODS

A total of 252 infants (gestation < or =28 weeks) born between 1 January 2000 and 30 June 2002 were divided into three groups: group 1, no significant PDA (n = 154); group 2, significant PDA which closed after medical treatment (n = 65); group 3, significant PDA remaining patent after medical treatment (n = 33). A significant PDA was defined by a left atrium to aortic root ratio of >1.4 or a ductal diameter >1.5 mm with a left to right shunt.

RESULTS

Twenty four (10%) infants died at median (interquartile range) 15.5 (9-35) days. After adjustment for gestational age, relative to group 1, the infants from group 3 were at a 4.02 times increased risk of death (95% confidence interval 1.12 to 14.51). There was no significant difference between groups in the incidence of chronic lung disease, chronic lung disease or death, necrotising enterocolitis, intraventricular haemorrhage, duration of oxygen, or hospital stay.

CONCLUSION

Mortality was higher in infants with a persistent PDA, but other morbidities were not significantly different. A randomised trial is needed to determine whether surgical ligation will reduce mortality in such infants.

Utility of rapid B-type natriuretic peptide assay for diagnosis of symptomatic patent ductus arteriosus in preterm infants

OBJECTIVE

In preterm infants, the rapid and accurate determination of the presence of a hemodynamically significant patent ductus arteriosus (PDA) is extremely important, but this is often difficult. Plasma B-type natriuretic peptide (BNP) measurement has been reported to be a helpful aid in the diagnosis of hemodynamically significant PDA in preterm infants. The aim of our study was to investigate the usefulness of a rapid BNP assay as a diagnostic marker of symptomatic PDA (sPDA) in preterm infants.

METHODS

Sixty-six preterm infants, ranging from 25 to 34 gestational weeks of age, underwent clinical and echocardiographic examinations for PDA every other day from the third day of life until the disappearance of ductal flow. Blood samples were collected and plasma BNP concentrations were measured simultaneously using a commercial kit, (Triage BNP test kit; Biosite Diagnositics, San Diego, CA). When > or =2 clinically significant features of PDA were noted, and a large ductal flow was confirmed by color Doppler echocardiography, sPDA was diagnosed and treated with indomethacin.

RESULTS

On the third day after birth, the mean BNP concentration in the sPDA group (n = 23) was significantly higher than in the control group (n = 43) (2896 +/- 1627 vs 208 +/- 313 pg/mL). Seventeen infants (74%) in the sPDA group became asymptomatic after an initial course of indomethacin and their BNP levels concomitantly decreased. Moreover, BNP concentrations were significantly correlated with the magnitudes of the ductal shunt, such as the ratio of left atrial to aortic root diameter and the diastolic flow velocity of the left pulmonary artery (r = 0.726 and 0.877). The area under the receiver operator characteristic curve for the detection of sPDA was high: 0.997 (95% confidence interval: 0.991-1.004). The best cutoff of BNP concentration for the diagnosis of sPDA was determined to be 1110 pg/mL (sensitivity: 100%; specificity: 95.3%).

CONCLUSION

In preterm infants, the circulating BNP levels correlated well with the clinical and echocardiographic assessments of PDA. Although not a stand-alone test, the rapid BNP assay provides valuable information for the detection of infants with sPDA that require treatment. Moreover, serial BNP measurements may be of value in determining the clinical course of PDA in preterm infants.

Skin reflectance changes in preterm infants with patent ductus arteriosus

INTRODUCTION

Patent ductus arteriosus (PDA) is a common complication in preterm infants. While two-dimensional echocardiography is the method of choice for diagnosing a PDA, clinical signs are known to be of limited value.

STUDY DESIGN

Haemodynamically significant PDA (hs-PDA) was defined as a ductal left-to-right shunt with elevated left atrial/aortic root ratio ( > 1.6:1), a ductal diameter > 2 mm, retrograde diastolic flow exceeding 30% of the anterograde flow and anterograde peak diastolic flow velocity in left pulmonary artery > 50 cm/s. A hs-PDA may affect the cerebral circulation and skin color is known to be related to local perfusion. In this study, we tested the value of a caudal-to-cephalic skin reflectance differential in detecting preterm infants with hs-PDA. The study was blinded and prospective.

SUBJECTS

Fifteen infants with a hs-PDA (M: 8, F: 7; gestational age: 28.0 +/- 2.0 weeks, birth weight: 880 +/- 130 g) and 15 gender- and gestational age-matched infants without a haemodynamically significant PDA (M: 8, F: 7; gestational age: 28.2 +/- 2.3 weeks, birth weight: 885 +/- 135 g) participated to the study.

OUTCOME MEASURE

Skin reflectance measurements were performed using a reflectance spectrophotometer (CM-2600d/2500d, Minolta, Osaka, Japan). Sole ("postductal" site) to forehead ("preductal" site) skin reflectance ratio (caudal-to-cephalic ratio).

RESULTS

hs-PDA infants showed significantly lower forehead light reflectance values on for the whole visible spectrum (p < or = 0.043) with the exception of 580-590 nm (p = 0.058), whereas no statistically significant differences were observed for the sole skin reflectance between the two groups in the examined visible spectrum. Consequently, hs-PDA infants showed a significantly higher caudal to cephalic ratio in the 410-430 nm (p < or = 0.042), 460-530 nm (p < or = 0.027) and 590-700 nm (p < or = 0.011) wavelength ranges.

CONCLUSIONS

These findings may provide a previously unrecognised clinical marker for haemodynamically significant PDA in preterm infants, thus predicting those preterm infants who may require intervention for PDA.