Treatment of patent ductus arteriosus

Closing the Gap: Investigation of Various Approaches in the Management of Patent Ductus Arteriosus

In preterm newborns with extremely low birth weights, patent ductus arteriosus (PDA), which is defined as a remnant connection between the aorta and pulmonary artery after 72 hours of birth, is frequently linked to substantial morbidity and mortality. If left untreated, a hemodynamically significant PDA (hsPDA) increases the risk for bronchopulmonary dysplasia, necrotizing enterocolitis, and intraventricular hemorrhage among other morbidities, and can even lead to death. While instances of patent ductus arteriosus (PDA) resolving on their own are frequent, the primary approach for managing PDA closure in premature infants involves pharmacological interventions, commonly utilizing indomethacin, ibuprofen, or paracetamol. However, with these pharmacological treatment options, there is an increased risk of renal toxicity, gastrointestinal bleeding, and reopening of PDA among other complications. If pharmacological interventions are not successful or contraindicated, PDA can be closed via transcatheter closure or surgical ligation. As with any medically invasive procedure, it is not without risks and can lead to long-term complications. This review explores the different management options and the benefits and outcomes of conservative management vs. active management in order to get one step closer to standardizing the treatment for PDA. With so much controversy surrounding the best management option, there is a lack of evidence to support one treatment method superior to the other in reducing overall mortality, and this needs to be explored further.

Therapeutic strategy of patent ductus arteriosus in extremely preterm infants

The ductus arteriosus is likely to close without treatment in most infants born at gestational age (GA) > 28 weeks (73%), and those with birth weight > 1000 g (94%). However, the rates of spontaneous ductal closure among less mature or smaller infants with respiratory distress syndrome are not known. Extremely preterm infants born at GA < 28 weeks are associated with a high risk of severe intraventricular hemorrhage (IVH) or pulmonary hemorrhage, which usually occur within 72 h after birth and affect mortality and long-term neurological development. These serious hemorrhagic complications may be closely related to hemodynamic changes caused by a hemodynamically significant patent ductus arteriosus (hs-PDA). While prophylactic indomethacin has been shown to reduce the rates of PDA, PDA ligation, severe IVH and early pulmonary hemorrhage, the available evidence does not support its prophylactic use in preterm infants. Symptomatic or late treatment is associated with lower success rate, and increased complications of a hs-PDA. The issue of "to treat or not to treat a PDA" is controversial. Considering the relationship between the effectiveness and timing of pharmacological treatment, early targeted treatment may be an alternative approach for the early identification of a hs-PDA in specific high-risk patient population, especially infants <26 weeks GA who are at the highest risk of severe IVH or pulmonary hemorrhage. Serial echocardiographic studies can be used to select patients who are candidates for early targeted medical treatment of hs-PDA. Surgical ligation of PDA, and transcatheter closure if proven to be safe, can be used as back-up therapy for patients who fail medical treatment and continue to have cardiopulmonary compromise.

Paracetamol vs. Ibuprofen in Preterm Infants With Hemodynamically Significant Patent Ductus Arteriosus: A Non-inferiority Randomized Clinical Trial Protocol

Background: Currently, the first line treatment of persistent ductus arteriosus (PDA) is either indomethacin or ibuprofen. However, the potentially life-threatening side effects associated to their use have prompted physicians to look for alternative options. The incorporation of paracetamol as an alternative to ibuprofen in the management of PDA is still based on insufficient clinical evidence. Hence, more clinical trials are needed to establish a therapeutic role for paracetamol in the management of PDA that take into consideration short- and long-term safety and efficacy outcomes. Study Design: This is a non-inferiority, randomized, multicenter, double-blinded study to evaluate the efficacy, and safety of intravenous (IV) paracetamol vs. IV ibuprofen (standard treatment) for PDA in preterm patients with a gestational age ≤ 30 weeks. At baseline, patients will be randomized (1:1) to treatment with paracetamol or ibuprofen. The primary endpoint is closure of the ductus after the first treatment course. Secondary endpoints are related to effectiveness (need for a second treatment course, rescue treatment, reopening rate, time to definitive closure, need for surgical ligation), safety (early and long-term complications), pharmacokinetics, and pharmacodynamics, pharmacogenetics, pharmacoeconomics, and genotoxicity. Long-term follow-up to 24 months of corrected postnatal age will be performed using Bayley III neurodevelopmental scale. Trial Registration: ClinicalTrials.gov Identifier: NCT04037514. EudraCT: 2015-003177-14.

High-sensitivity troponin T in preterm infants with a hemodynamically significant patent ductus arteriosus

OBJECTIVE

To investigate if a hemodynamically significant patent ductus arteriosus (hsPDA) leads to elevated high-sensitivity troponin T (hsTnT) and NTproBNP levels in serum.

STUDY DESIGN

Infants <34 weeks and <1500 g were prospectively enrolled, except those with major congenital or chromosomal anomalies. An echocardiogram (ECHO) was performed and hsTnT and NTproBNP were measured within 5 days of life and repeated after treatment of hsPDA. Clinical, ECHO, and hsTnT data were analyzed using Student t-test, two proportion z-test, and regression analysis.

RESULTS

Seventy infants were enrolled. Infants in the hsPDA group had lower gestation and birth weight. Mean hsTnT and NTproBNP levels in the hsPDA group were higher compared to the group without an hsPDA, with levels being 251.54 vs 161.6 pg/ml, p < 0.01 for hsTnT and 18181.02 vs 3149.23 pg/ml, p < 0.001 for NTproBNP.

CONCLUSION

HsPDA leads to increased hsTnT and NTproBNP levels in preterm infants without affecting cardiac function.

Non-pharmacological management of a hemodynamically significant patent ductus arteriosus

The association between the patent ductus arteriosus (PDA) and neonatal morbidity, mortality and poor neurodevelopmental outcome in later childhood has been the focus of intense debate for decades. The lack of evidence supporting therapeutic strategies aimed at achieving PDA closure has led to the widespread adoption of conservative management aimed at mitigating the impact of shunt volume without achieving ductal closure. In this article, we review this management approach, describe the supportive evidence and potential complications associated with this strategy.

Patent Ductus Arteriosus in Preterm Infants, Part 1: Understanding the Pathophysiologic Link Between the Patent Ductus Arteriosus and Clinical Complications

The clinical guidelines for treating patent ductus arteriosus (PDA) have significantly evolved over the last decades from treating any ductal shunt to more conservative management where only the hemodynamically significant patent ductus arteriosus (HSPDA) is treated. This shift has resulted largely from a lack of evidence from randomized controlled trials supporting a relationship between treating a PDA and improving long-term neonatal outcomes. However, there are many unresolved issues. There is no consensus on the precise definition of HSPDA requiring treatment or a clear understanding of when to treat HSPDA. Moreover, the current evidence shows worsening of the long-term neurodevelopmental outcome for infants undergoing surgical PDA ligation.<br/> The presence of physiologic variability among preterm infants, and the presence of different compensatory mechanisms may make it difficult to establish a link between pathophysiology and long-term outcomes. That is, the physiologic variability cannot be simply assessed by randomly assigning infants into two arms of a study. Relying on research from animal and human studies, this article explains the link between the pathophysiology of a PDA and neonatal outcomes.

The impact of a dedicated patent ductus arteriosus ligation team on neonatal health-care outcomes

OBJECTIVE

The decision to perform patent ductus arteriosus (PDA) ligation is controversial. Patient selection is oftentimes poorly standardized, leading to delays in referral and inappropriate intervention. A system for PDA ligation categorization and triaging process was introduced in 2006 at a quaternary hospital in Canada to streamline referrals and enhance perioperative care. We aimed to evaluate the impact of this dedicated PDA ligation triaging system comparing pre- and postimplementation of this system.

STUDY DESIGN

We performed a retrospective chart review. Demographic and cardiorespiratory data of neonates ⩽30 weeks gestation age at birth, who were referred for and/or had a PDA ligation performed during two distinct epochs (EPOCH 1 (2003 to 2005) and EPOCH 2 (2010 to 2012)), were analyzed. All surgeries were performed at The Hospital for Sick Children, the regional referral center for PDA ligation. The primary outcome was incidence of PDA ligation and procedural cancellations. Secondary outcomes included postoperative need for cardiovascular or respiratory support. Subgroup analysis was performed in neonates <1000 vs >1000 g at the time of surgery during both epochs.

RESULT

A total of 198 neonates underwent surgery with no difference in baseline demographics between epochs. The incidence of PDA ligation as a proportion of total live births under 30 weeks in Central East Region of Ontario was lower in the second epoch (EPOCH 1: 117/1092 (10.7%) vs EPOCH 2: 81/1520 (5.3%)). During the second epoch, 24% of referrals for surgery were canceled after review by our PDA ligation team. There were no overall differences in the proportion of neonates with oxygenation failure, ventilation failure or Post-Ligation Cardiac Syndrome (PLCS), after surgery, between epochs. The proportion of neonates who developed systemic hypotension was higher in patients <1000 g (n=34 (34%) vs n=17 (17.4%), P=0.01) at the time of surgery. In addition, we identified a reduction in the proportion of neonates <1000 g who developed PLCS in EPOCH 2. On the contrary, there was an increase in the proportion of neonates >1000 g who developed ventilation failure in EPOCH 2.

CONCLUSION

The presence of dedicated triaging and management system enhances efficiency of referral process through careful selection of patients for PDA ligation and optimizes perioperative management. We demonstrated a reduction in the incidence of PDA ligation without any negative impact on short-term neonatal morbidity. The use of targeted neonatal echocardiography in the assessment of PDA shunt volume and guiding postoperative decision making is likely to have contributed to these findings.

A prospective study of maternal preference for indomethacin prophylaxis versus symptomatic treatment of a patent ductus arteriosus in preterm infants

Background

The management of a patent ductus arteriosus in preterm infants continues to be debated among neonatologists due to the absence of concrete evidence that precisely weighs the long term outcomes of active, early intervention against a conservative approach. In the majority of institutions, parents are encouraged to play an active role in the complex, decision –making processes with regard to the care of their infants. The objective of this study is to elicit maternal preferences for indomethacin prophylaxis versus treatment of a patent ductus arteriosus (PDA) in extremely low birth weight (ELBW) infants, utilizing a decision aid instrument (DAI).

Methods

Healthy and high risk pregnant women at 23–28 weeks gestation, and mothers of admitted ELBW infants were enrolled. A computer based, validated DAI was utilized during interviews. The DAI first provides information about prematurity and concurrent morbidities with comprehensive facts of the pros and cons about prophylactic versus treatment options. It subsequently coaches participants how to select values and preferences based on their decisions. A 17-item questionnaire assessed and valued each short and long term morbidity of extreme prematurity and preferred choice for PDA management.

Results

Two hundred ninety nine subjects were enrolled; 75% were healthy women at 23–28 weeks gestation, 19% were high risk and 6% recently delivered an ELBW infant. Eighty-two percent preferred a prophylactic indomethacin strategy versus symptomatic treatment for the management of PDA. Across a spectrum of potential morbidities, the occurrence of severe intraventricular hemorrhage was viewed by mothers as the most un-wanted outcome irrespective of the two proposed options.

Conclusions

In contrast to neonatal practitioners, mothers who used this particular DAI strongly endorsed prophylactic indomethacin versus a treatment intervention for the management of PDA in preterm infants.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0353-4) contains supplementary material, which is available to authorized users.

Current controversies in the management of patent ductus arteriosus in preterm infants

OBJECTIVE

Patent ductus arteriosus is very commonly seen in very low birth weight (VLBW) infants, affecting about one-third. The present review tries to identify the group of VLBW infants who need active intervention in day-to-day practice and to determine the mode of intervention, based on current published literatures.

METHODS

We searched the Cochrane library, MEDLINE, EMBASE and CINAHL databases, and reference that of identified trials.

RESULTS AND CONCLUSIONS

Preterm infants with a birth weight of <800g are at risk of significant morbidity and mortality from PDA; it would be reasonable to treat them when symptomatic or if requiring positive pressure ventilator support. Those weighing >800g are unlikely to need treatment unless they are ventilator-dependent or show evidence of congestive heart failure.

Cardiovascular magnetic resonance of cardiac function and myocardial mass in preterm infants: a preliminary study of the impact of patent ductus arteriosus

BACKGROUND

Many pathologies seen in the preterm population are associated with abnormal blood supply, yet robust evaluation of preterm cardiac function is scarce and consequently normative ranges in this population are limited. The aim of this study was to quantify and validate left ventricular dimension and function in preterm infants using cardiovascular magnetic resonance (CMR). An initial investigation of the impact of the common congenital defect patent ductus arteriosus (PDA) was then carried out.

METHODS

Steady State Free Procession short axis stacks were acquired. Normative ranges of left ventricular end diastolic volume (EDV), stroke volume (SV), left ventricular output (LVO), ejection fraction (EF), left ventricular (LV) mass, wall thickness and fractional thickening were determined in "healthy" (control) neonates. Left ventricular parameters were then investigated in PDA infants. Unpaired student t-tests compared the 2 groups. Multiple linear regression analysis assessed impact of shunt volume in PDA infants, p-value ≤ 0.05 being significant.

RESULTS

29 control infants median (range) corrected gestational age at scan 34+6(31+1-39+3) weeks were scanned. EDV, SV, LVO, LV mass normalized by weight and EF were shown to decrease with increasing corrected gestational age (cGA) in controls. In 16 PDA infants (cGA 30+3(27+3-36+1) weeks) left ventricular dimension and output were significantly increased, yet there was no significant difference in ejection fraction and fractional thickening between the two groups. A significant association between shunt volume and increased left ventricular mass correcting for postnatal age and corrected gestational age existed.

CONCLUSION

CMR assessment of left ventricular function has been validated in neonates, providing more robust normative ranges of left ventricular dimension and function in this population. Initial investigation of PDA infants would suggest that function is relatively maintained.

Pocket echocardiography system for detection of patent ductus arteriosus in neonates

BACKGROUND

Neonates are commonly referred for a cardiology consult and an echocardiogram to rule out patent ductus arteriosus (PDA).

OBJECTIVES

Evaluate the usefulness of current pocket echocardiography system (PES) in PDA detection compared to traditional full-featured echo system (FFES).

HYPOTHESIS

The determination of the presence of a PDA in neonates can be done using PES.

METHODS

Fifty newborns with orders for echo evaluation were included in this study. A 5-minute PES scan was performed first. Then a full echo study was performed on a traditional FFES. Images were evaluated by three pediatric cardiologists blinded to the patients and the FFES results.

RESULTS

The overall accuracy of reviewers rating PES versus FFES to rule in PDA had low false-positive rates 9.5% (95% CI: 1.2-30%), 11.8% (95% CI: 1.5-36%), 11.1% (95% CI: 1.4-35%) and the false-negative rate to rule out PDA was 0% (95% CI: 0-18%), 5.5% (95% CI: 0.14-27%), 0% (95% CI: 0-26%) for each reviewer 1, 2, and 3, respectively. Upon further analysis, PES scan was shown not to be accurate on infants with body weight below 1000 g with encouraging results for infants above 1000 g and those >37 weeks gestational age.

CONCLUSIONS

Our results suggest that the current PES could potentially be used in larger and near-term infants but has less than acceptable performance in low birth weight and premature infants in determining who should undergo a FFES study for persistent PDA diagnosis. Improvements in the technology along with developing limited training protocols for noncardiology personnel should make it possible for PES scan to be used as a screening tool and as an extension of physical examination especially in limited resource settings.

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.

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.

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.

A high ductal flow velocity is associated with successful pharmacological closure of patent ductus arteriosus in infants 22-27 weeks gestational age

Objective. To identify factors affecting closure of patent ductus arteriosus (PDA) in newborn infants born at 22–27 weeks gestational age (GA) during pharmacological treatment with cyclooxygenase inhibitors. Method. Infants born at 22–27 weeks of GA between January 2006 and December 2009 who had been treated pharmacologically for PDA were identified retrospectively. Medical records were assessed for clinical, ventilatory, and outcome parameters. Echocardiographic examinations during treatment were reviewed. Results. Fifty-six infants were included in the study. Overall success rate of ductal closure with pharmacological treatment was 52%. Infants whose PDA was successfully closed had a higher GA (25 + 4 weeks versus 24 + 3 weeks; P = 0.047), and a higher pretreatment left to right maximal ductal flow velocity (1.6 m/s versus 1.1 m/s; P = 0.023). Correcting for GA, preeclampsia, antenatal steroids, and age at start of treatment, a higher maximal ductal flow velocity was still associated with successful ductal closure (OR 3.04; P = 0.049). Conclusion. Maximal ductal flow velocity was independently associated with success of PDA treatment.

Hemodynamic effects of fluid restriction in preterm infants with significant patent ductus arteriosus

OBJECTIVE

To determine the hemodynamic impact of fluid restriction in preterm newborns with significant patent ductus arteriosus.

STUDY DESIGN

Newborns ≥24 and <32 weeks' gestational age with significant patent ductus arteriosus were eligible for this prospective multicenter observational study. We recorded hemodynamic and Doppler echocardiographic variables before and 24 hours after fluid restriction.

RESULTS

Eighteen newborns were included (gestational age 24.8 ± 1.1 weeks, birth weight 850 ± 180 g). Fluid intake was decreased from 145 ± 15 to 108 ± 10 mL/kg/d. Respiratory variables, fraction of inspired oxygen, blood gas values, ductus arteriosus diameter, blood flow-velocities in ductus arteriosus, in the left pulmonary artery and in the ascending aorta, and the left atrial/aortic root ratio were unchanged after fluid restriction. Although systemic blood pressure did not change, blood flow in the superior vena cava decreased from 105 ± 40 to 61 ± 25 mL/kg/min (P < .001). The mean blood flow-velocity in the superior mesenteric artery was lower 24 hours after starting fluid restriction.

CONCLUSIONS

Our results do not support the hypothesis that fluid restriction has beneficial effects on pulmonary or systemic hemodynamics in preterm newborns.

Use of targeted neonatal echocardiography to prevent postoperative cardiorespiratory instability after patent ductus arteriosus ligation

OBJECTIVES

To investigate the value of targeted neonatal echocardiography (TnECHO) in predicting cardiorespiratory instability after patent ductus arteriosus (PDA) ligation, and to evaluate the impact of TnECHO-directed care.

STUDY DESIGN

We reviewed serial echocardiography evaluations of 62 preterm infants after PDA ligation to investigate the relationship between indices of myocardial performance and postoperative cardiorespiratory instability. A predictive model was developed based on TnECHO criteria, with targeted initiation of intravenous milrinone. A comparative evaluation was performed between matched infants in the previous era (epoch 1; n=25) and current era (epoch 2; n=27) of TnECHO-guided treatment.

RESULTS

Left ventricular output <200 mL/kg/min at 1 hour after PDA ligation was a sensitive predictor of systemic hypotension and the need for inotropes, and was used for initiation of i.v. milrinone infusion in epoch 2. Infants treated with milrinone had a lower incidence of ventilation failure (15% vs 48%; P=.02) and less need for inotropes (19% vs 56%; P=.01), and showed a trend toward improved oxygenation (P=.08).

CONCLUSION

TnECHO facilitates early detection of infants at greatest risk for subsequent cardiorespiratory deterioration. Administration of milrinone to neonates with low cardiac output may lead to improved postoperative stability.

A decision aid for considering indomethacin prophylaxis vs. symptomatic treatment of PDA for extreme low birth weight infants

BACKGROUND

Decision Aids (DA) are well established in various fields of medicine. It can improve the quality of decision-making and reduce decisional conflict. In neonatal care, and due to scientific equipoise, neonatologists caring for extreme low birth weight (ELBW) infants are in need to elicit parents' preferences with regard to the use of indomethacin therapy in ELBW infants. We aimed to develop a DA that elicits parents' preferences with regard to indomethacin therapy in ELBW infants.

METHODS

We developed a DA for the use of the indomethacin therapy in ELBW infants according to the Ottawa Decision Support Framework. The development process involved parents, neonatologists, DA developers and decision making experts. A pilot testing with healthy volunteers was conducted through an evaluation questionnaire, a knowledge scale, and a validated decisional conflict scale.

RESULTS

The DA is a computer-based interactive tool. In the first part, the DA provides information about patent ductus arteriosus (PDA) as a disease, the different treatment options, and the benefits and downsides of using indomethacin therapy in preterm infants. In the second part, it coaches the parent in the decision making process through clarifying values and preferences. Volunteers rated 10 out of 13 items of the DA positively and showed significant improvement on both the knowledge scale (p = 0.008) and the decisional conflict scale (p = 0.008).

CONCLUSION

We have developed a computer based DA to assess parental preferences with regard to indomethacin therapy in preterm infants. Future research will involve measurement of parental preferences to guide and augment the clinical decisions in current neonatal practice.

Ibuprofen lysine (NeoProfen) for the treatment of patent ductus arteriosus

Patent ductus arteriosus (PDA) affects approximately 31% of infants whose birth weight is between 501 and 1500 g. The ductus arteriosus is a blood vessel that allows blood to bypass the pulmonary vasculature in utero. Oxygen delivery and elimination of prostaglandins are essential for the closure of the ductus after birth. For years, indomethacin has been the drug of choice for the treatment of PDA in the USA. Undesirable adverse effects prompted researchers to seek alternative agents. In April 2006, the US Food and Drug Administration approved the use of ibuprofen lysine (NeoProfen) for closure of clinically significant PDA in premature neonates. Ibuprofen's mechanism of action for closure of PDA is believed to be through the inhibition of prostaglandins. Clinical studies have shown ibuprofen to be as effective as indomethacin with fewer adverse effects.

Transcatheter closure of patent ductus arteriosus: Evaluating the effect of the learning curve on the outcome

Background and Objectives:

Initial experience with transcatheter closure of patent ductus arteriosus (PDA) using detachable coils and Amplatzer duct occluder devices is reported. We evaluated the outcome, complications, and influence of the learning curve, and also assessed the need of surgical backup for such interventional procedures.

Methods:

From January 2000 to December 2004, 121 patients underwent transcatheter closure of PDA. Aortic angiogram was performed to evaluate the size, position, and shape of the duct for appropriately choosing the occluder device type and size. A second aortic angiogram was performed 10 minutes after device deployment. Echocardiography was repeated at intervals of 24 hours, then at 1, 3, and 6 months after the procedure to assess complications. Stepwise multiple regression analysis was used to assess the role of experience in improving the outcome of the procedure.

Results:

Of 121 cases, four patients had pulmonary artery embolization of the occluder device which was successfully retrieved in the catheterization laboratory, while two others had embolization that required surgical intervention. Four patients had temporary residual leak, nine had protrusion of the device into the aorta without significant Doppler pressure gradient or hemolysis on follow-up, and five had partial hemodynamically insignificant obstruction to the left pulmonary artery. Statistical analysis showed that the effect of the learning curve and experience was responsible for 93% improvement in the procedural outcome over the five-year study period.

Conclusion:

Transcatheter occlusion of PDA is safe and effective alternative to surgery. Complications occurred in those with unfavorable duct anatomy and with the use of multiple coils. Surgical backup was important for such interventional procedures. Experience played a major role in the proper choice of device type and size which greatly influenced the outcome of the procedure.

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.

Anesthetic technique and postoperative outcome in preterm infants undergoing PDA closure

OBJECTIVE

To describe the various anesthetic techniques used for surgical closure of PDA in premature infants at the Montreal Children's Hospital and assess their impact on postoperative outcome.

STUDY DESIGN

The charts of all preterms who underwent PDA ligation during a 21-month period were reviewed for preoperative status, intraoperative anesthetic management and postoperative outcome. We determined the associations between independent variables and two postoperative outcome variables: unstable postoperative respiratory course (UPRC) and hypotension.

RESULT

The mean weight at surgery of the 33 infants was 1.031±0.29 kg. All infants, but one, received intraoperative opioids. Eight patients presented UPRC. Mean fentanyl doses were 5.3±2.6 mcg kg(-1) for patients with UPRC vs 22.6±16.6 mcg kg(-1) for patients without UPRC (P=0.004). Applying the receiver-operator characteristic curve (ROC), 10.5 mcg kg(-1) of fentanyl was established as the dose that discriminated and identified patients who experienced UPRC. The postnatal and postmenstrual age of the patient, birthweight, current weight, ventilator settings preoperatively, previous courses of indomethacin, sex and preoperative creatinine, were not correlated with the dose of fentanyl equivalent used. Logistic regression did not show a relationship between any of the previously mentioned factors and receiving a fentanyl equivalent of >10.5 mcg kg(-1). The only factor associated with the total fentanyl equivalent dose (as a continuous variable) or receiving <10.5 mcg kg(-1) (as a dichotomous variable) was the identity of the anesthetist involved, P<0.001.

CONCLUSION

We conclude that the use of at least 10.5 mcg kg(-1) of fentanyl equivalent as a component of the anesthetic regimen for surgical closure of a PDA in premature infants, avoids an unstable postoperative respiratory course.

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.

Renal effects of ibuprofen for the treatment of patent ductus arteriosus in premature infants

In recent years ibuprofen has been proposed for the treatment of patent ductus arteriosus (PDA) as it has been proved to be equally as effective as indomethacin and shows fewer cerebral blood flow, intestinal and renal hemodynamic effects. A number of studies and several meta-analyses comparing both drugs are now available that debate whether indomethacin or ibuprofen should be used for PDA prophylaxis or closure. This review examines the available knowledge on the specific issue of the effects of ibuprofen on kidney function, as improved renal tolerance is a major argument in favor of its use in the routine treatment of PDA. There is sufficient evidence to consider that ibuprofen, at the currently proposed dosing regimen, has a similar efficacy to indomethacin but is better tolerated by the neonatal kidney when employed for the treatment of established PDA. However, adverse effects of ibuprofen have been evidenced both in trials on the use of ibuprofen for the prevention of PDA and of intraventricular hemorrhage-periventricular hemorrhage (IVH-PVH), and in experimental studies on a neonatal, anesthetized animal model. Thus ibuprofen, as with other cyclooxygenase (COX) inhibitors, may not be exempt from causing renal adverse effects, especially in circumstances when renal prostaglandin activation is maximal (i.e., when administrated early after birth, in more immature patients and in certain situations such as in the anesthetized rabbit). However, although the issue has been addressed extensively in the last decades, there is insufficient evidence that therapeutic intervention in PDA is beneficial in terms of mortality or clinically significant morbidity outcomes. Studies aimed at resolving this key issue are still needed.

N-terminal probrain natriuretic peptide and patent ductus arteriosus in preterm infants

OBJECTIVE

To determine whether plasma N-terminal probrain natriuretic peptide (NT-proBNP) in premature infants could identify hemodynamically significant patent ductus arteriosus (HsPDA) and to determine the correlation between serial plasma NT-proBNP and echocardiographic assessment of ductal shunting.

STUDY DESIGN

An observational study involving 35 preterm infants who underwent echocardiographic assessment for PDA on day 2, 4 and 7 of life with simultaneous blood sampling for determination of NT-proBNP concentrations. HsPDA was diagnosed by left-to-right ductal shunt on color Doppler, measuring diameter >1.5 mm on two-dimensional echocardiography plus > or =2 clinical features of PDA.

RESULT

Plasma NT-proNBP levels on day 2 in the HsPDA group (n=12) were significantly higher than in non-HsPDA group (n=23) with a median of 16,353 pg ml(-1) (interquartile range (IQR), 12,360-33,459; range, 10,316-104,998) vs 3914 pg ml(-1) (IQR, 2601-5782; range, 1535-19,516) (P<0.001), respectively. Eight infants (67%) in the HsPDA group responded to an initial course of indomethacin or ibuprofen and their NT-proBNP levels significantly decreased within 48 h after treatment compared with non-responders (P=0.007). NT-proBNP concentrations were significantly correlated with left atrial to aortic root ratio. A cut-off NT-proBNP on day 2 of 10,180 pg ml(-1) offered the best predictive values for HsPDA with a sensitivity of 100% and a specificity of 91%.

CONCLUSION

Plasma NT-proBNP on day 2 was found as a sensitive marker for predicting HsPDA in preterm infants. Successful closure of PDA was also correspondent with the decline in plasma NT-proBNP.

Cerebral and splanchnic hemodynamics after duct ligation in very low birth weight infants

OBJECTIVE

To describe mesenteric and cerebral blood flow velocities after surgical patent ductus arteriosus (PDA) closure in premature infants.

STUDY DESIGN

We measured middle cerebral artery (MCA), celiac artery (CA), and superior mesenteric artery (SMA) Doppler ultrasound scanning blood flow velocity (BFV) preoperatively, 3 and 24 hours after ligation.

RESULTS

We studied 32 infants, with a mean (+/- SD) birthweight of 762 +/- 170 g and gestational age of 25.6 +/- 1.4 weeks at a mean age of 34 +/- 13 days. Significant changes in end-diastolic (EDV), average velocity (AV), and vascular resistance were measured in all 3 vessels by 3 hours. AV increased significantly in the CA and SMA within 3 hours; however, no significant increase in MCA AV was found until 24 hours after surgery.

CONCLUSION

PDA ligation significantly changes BFV in the MCA, CA, and SMA. In the MCA vascular tone is acutely modulated, with no change in AV at 3 hours. In the CA and SMA, AV increases acutely after ligation. These different patterns of change in BFV suggest region-specific adaptation to surgical PDA closure.

Genetic contribution to patent ductus arteriosus in the premature newborn

BACKGROUND

The most common congenital heart disease in the newborn population, patent ductus arteriosus, accounts for significant morbidity in preterm newborns. In addition to prematurity and environmental factors, we hypothesized that genetic factors play a significant role in this condition.

OBJECTIVE

The objective of this study was to quantify the contribution of genetic factors to the variance in liability for patent ductus arteriosus in premature newborns.

PATIENTS AND METHODS

A retrospective study (1991-2006) from 2 centers was performed by using zygosity data from premature twins born at < or =36 weeks' gestational age and surviving beyond 36 weeks' postmenstrual age. Patent ductus arteriosus was diagnosed by echocardiography at each center. Mixed-effects logistic regression was used to assess the effect of specific covariates. Latent variable probit modeling was then performed to estimate the heritability of patent ductus arteriosus, and mixed-effects probit modeling was used to quantify the genetic component.

RESULTS

We obtained data from 333 dizygotic twin pairs and 99 monozygotic twin pairs from 2 centers (Yale University and University of Connecticut). Data on chorioamnionitis, antenatal steroids, gestational age, body weight, gender, respiratory distress syndrome, patent ductus arteriosus, necrotizing enterocolitis, oxygen supplementation, and bronchopulmonary dysplasia were comparable between monozygotic and dizygotic twins. We found that gestational age, respiratory distress syndrome, and institution were significant covariates for patent ductus arteriosus. After controlling for specific covariates, genetic factors or the shared environment accounted for 76.1% of the variance in liability for patent ductus arteriosus.

CONCLUSIONS

Preterm patent ductus arteriosus is highly familial (contributed to by genetic and environmental factors), with the effect being mainly environmental, after controlling for known confounders.

Hypotension in preterm infants with significant patent ductus arteriosus: effects of dopamine

OBJECTIVE

To study the effects of dopamine on systemic arterial pressure (SAP) and systemic blood flow (SBF) (estimated with the superior vena cava [SVC] flow) in preterm infants with hypotension and patent ductus arteriosus (PDA).

STUDY DESIGN

Clinical and echocardiographic variables were measured before and 2 hours after starting dopamine in premature infants <32 weeks gestational age with PDA and systemic hypotension.

RESULTS

Seventeen premature infants were included (gestational age, 28+/-2 weeks; birth weight, 1030 +/- 400 g). A mean rate of 8 +/- 2 microg/kg/min of dopamine raised SAP from 30 +/- 3 to 41 +/- 5 mm Hg (P < .05), and the pulmonary artery pressures from 25 +/- 5 to 32 +/- 8 mm Hg (P < .05). The SVC flow increased by 30% (from 130 +/- 40 to 170 +/- 44 mL/kg/min; P < .05). The left ventricular output and the end-diastolic and mean left pulmonary artery blood flow velocities did not change despite the increase in pulmonary artery pressure.

CONCLUSION

In preterm infants with hypotension and PDA, dopamine (<10 microg/kg/min) increases the systemic blood pressure and the systemic blood flow. Our results suggest that dopamine decreases left-to-right shunting across ductus arteriosus, caused by a rise in pulmonary vascular resistances.

B-type natriuretic peptide to predict ductus intervention in infants <28 weeks

Patent ductus arteriosus (PDA) is frequent in neonates with gestational age of less than 28 wk. Clinical and echocardiographic signs define hemodynamic significance of PDA, but do not reveal the need for PDA intervention in the first days of life. B-type natriuretic peptide (BNP) has been proposed as a screening tool for PDA in preterm infants. To determine whether BNP can predict the need for PDA intervention, plasma BNP was measured by chemiluminescence immunoassay in 67 preterm infants <28 wk (median 26) on the second day of life in a prospective blinded study. PDA intervention was based on specified clinical and echocardiographic findings. Twenty-four patients (intervention group) received treatment for PDA and 43 patients (controls) remained without intervention. BNP concentrations were higher in the intervention (median 1069 pg/mL) than in the control group (247 pg/mL, p < 0.001). BNP correlated positively with ductal size (R = 0.46, p < 0.001) and atrial/aortic root ratio (R = 0.54, p < 0.001). In conclusion, plasma BNP proved to be a good predictor for ductus intervention (area under the curve: 0.86) with the best cutoff at 550 pg/mL on the second day of life in ventilated infants less than 28 wk gestation (sensitivity: 83%; specificity: 86%).

Acute hemodynamic decompensation following patent ductus arteriosus ligation in premature infants

INTRODUCTION

Patent ductus arteriosus (PDA) ligation can lead to postoperative hemodynamic instability requiring inotropic support, termed hemodynamic decompensation. The purpose of this study was to prospectively determine the incidence, predictors, and clinical impact of hemodynamic decompensation after PDA ligation in preterm infants.

METHODS

All infants undergoing PDA ligation were eligible for this prospective cohort study. After undergoing ligation, patients were followed until 30 days after successful extubation, discharge from the NICU, or death. Data collection included perinatal and preoperative clinical information, operative details, postoperative course, and outcome.

RESULTS

Ninety-six preterm infants were enrolled and underwent PDA ligation. Hemodynamic decompensation occurred in 27 patients (28%). Overall in-hospital mortality rate was 18%. Mortality was significantly higher among infants that developed hemodynamic decompensation (33% vs 11%, p = .012). Hemodynamic decompensation was associated with an adjusted odds ratio (OR) for death of 3.1 (95% confidence interval: 1.0-9.5, p = .05). Lower estimated gestational age, lower corrected age, and higher rate of preoperative mechanical ventilation were significant predictors of hemodynamic decompensation.

CONCLUSION

Hemodynamic decompensation occurred in 28% of patients after PDA ligation, resulting in a significantly higher mortality. Younger patients requiring higher ventilator support are most likely to develop hemodynamic decompensation.

Multidetector CT evaluation of congenital lung anomalies

Congenital lung anomalies vary widely in their clinical manifestation and imaging appearance. Although radiographs play a role in the incidental detection and initial imaging evaluation in patients with clinical suspicion of congenital lung anomalies, cross-sectional imaging such as computer tomography (CT) is frequently required for confirmation of diagnosis, further characterization, and preoperative evaluation in the case of surgical lesions. Recently, with the development and widespread availability of multidetector CT scanners, CT has assumed a greater role in the noninvasive evaluation of congenital lung anomalies. The combination of fast speed, high spatial resolution, and enhanced quality of multiplanar reformation and three-dimensional reconstructions makes multidetector CT an ideal noninvasive method for evaluating congenital lung anomalies. In this article, the authors review the multidetector CT technique for evaluation of congenital lung anomalies. Important clinical aspects, characteristic imaging features, and key points that allow differentiation among various anomalies are highlighted for a variety of common and uncommon conditions.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Establishing normal values of central venous pressure in very low birth weight infants

The objective of this paper is to establish a reference range of central venous pressure (CVP) values during the first 4 days of life in very low birth weight (VLBW) infants. A prospective observational study with continuous monitoring of CVP in VLBW newborns who had an umbilical venous catheter (UVC) positioned in or near the right atrium is conducted. All UVCs were inserted as part of normal care of the infants. The mean CVP (mCVP) was monitored for 72 h from recruitment, or until the UVC was removed. The mean mCVP was calculated for each infant. The median of the mean mCVPs was then calculated. Data were analysed in 17 infants. The median gestational age was 27 weeks and median birth weight was 940 g. Sixteen were mechanically ventilated and of these, six also received continuous positive airway pressure (CPAP) during the study period. One infant received no respiratory support. One infant died during the study period. The lowest mean mCVP was 2.8 mmHg and the highest was 13.9 mmHg. The median mean mCVP was 4.9 mmHg (interquartile range 4.4-6.1). The normal range of CVP in VLBW infants during the first 4 days of life is wider than previously suggested.

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.

Conservative treatment for patent ductus arteriosus in the preterm

BACKGROUND

A patent ductus arteriosus (PDA) is common among preterms, and prophylactic medical treatment has been advocated as the first-line approach. Conservative treatment may result in similar outcome, but without exposure to the harmful side effects of medication. A retrospective analysis revealed a ductal closure rate of 94% after conservative treatment with adjustment of ventilation (lowering the inspiratory time and increasing positive end expiratory pressure) and fluid restriction.

OBJECTIVE

To study prospectively over one year the rate of PDA closure, and morbidity and mortality following conservative treatment.

METHOD

Prospective study (1 January 2005 - 31 December 2005) including 30 newborns <or=30 weeks' gestation, all of whom were being ventilated and required surfactant. Echocardiography was performed 48-72 h after birth. Clinically important PDA was conservatively treated as described above. The percentage of children with PDA, ductal ligation and major complications was determined.

RESULTS

Ten neonates (33%) developed a clinical important PDA. Following conservative treatment the duct closed in all neonates (100%), and none required ductal ligation or medical treatment. The rates of major complications were no higher than those reported by the Vermont Oxford Network and in the literature.

CONCLUSION

The managed care plan resulted in an overall ductal closure rate of 100%. These results suggest that conservative treatment of PDA is a worthy alternative to prophylactic medical treatment.

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.

Near-infrared spectroscopy as a screening tool for patent ductus arteriosus in extremely low birth weight infants

BACKGROUND

Patent ductus arteriosus (PDA) is frequent and potentially pathologic in preterm infants. A simple bedside tool to screen for ductal patency would assist in the care of extremely low birth weight (ELBW) infants.

OBJECTIVE

To investigate the utility of near-infrared spectroscopy (NIRS) in identifying ELBW infants who would benefit from early echocardiography.

METHODS

Tissue oxygen saturation (S(t)O(2)) was measured by NIRS in the lungs, brain, skeletal muscle and kidney of 20 ELBW infants. Comparisons were made between the S(t)O(2) in these organs and the need for intervention for a PDA. All studies were performed within the first 4 days of life. Similar measurements were performed following treatment with indomethacin in nine of the patients.

RESULTS

The S(t)O(2) of skeletal muscle (left deltoid) and kidney differed between the infants who were treated for PDA and those who were not (p = 0.01 for both). As a screen for a PDA requiring intervention, deltoid S(t)O(2) had sensitivity 77% and specificity 83%, and kidney S(t)O(2) had sensitivity 85% and specificity 83%. Following treatment with indomethacin, the low S(t)O(2) in the deltoid and kidney increased toward the range seen in patients who did not require treatment of a PDA. Inter- and intra-observer variability ranged from minimal to high.

CONCLUSION

This pilot study of a portable NIRS device shows encouraging efficacy in identifying ELBW infants who were likely to benefit from early echocardiography and subsequent intervention to close a PDA. Further study is warranted.

Patent ductus arteriosus in extremely preterm infants receiving phototherapy: does shielding the chest make a difference? A randomized, controlled trial

BACKGROUND

Patent ductus arteriosus (PDA), a common complication in extremely preterm infants, is associated with increased mortality and morbidity. Phototherapy has been associated with PDA, and one randomized, control trial has shown that shielding of the chest may decrease the risk of PDA.

AIM

To examine if chest shielding reduces the incidence and severity of PDA in extremely preterm infants.

STUDY DESIGN

Randomized clinical trial of infants < 29 wk gestation (stratified into two groups: < 27 wk gestation and 27-28 wk gestation).

METHODS

Following written parental consent, eligible infants were randomized to receive phototherapy, with or without a chest shield. Ductal parameters were assessed by Doppler echocardiogram in all infants prior to starting phototherapy and at 48 h after initiation, or earlier if phototherapy was discontinued.

RESULTS

54 infants were enrolled in the study. The incidence of PDA (shield 19/27 vs no shield 21/27), ductal size (1.4 vs 1.0 mm) and left atrial/aortic root (LA/Ao) ratio (1.2 vs 1.3) were similar in the two groups pre-phototherapy. There was no difference between the groups post-phototherapy in incidence (shield 12/27 vs no shield 13/27), ductal size (1.4 vs 1.5 mm) or LA/Ao ratio (1.1 vs 1.3).

CONCLUSION

Chest shielding did not alter the incidence or severity of PDA in our population of extremely preterm infants.

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.

Mesenteric oxyhemoglobin desaturation improves with patent ductus arteriosus ligation

Near-infrared spectroscopy was used to monitor cerebral and mesenteric regional oximetry in a preterm neonate undergoing surgical ligation of a patent ductus arteriosus. This patient initially demonstrated severe mesenteric oxyhemoglobin desaturation, which improved immediately following ductal ligation.