Randomised controlled trial of plasma protein fraction versus dopamine in hypotensive very low birthweight infants

Comparative efficacy of volume expansion, inotropes and vasopressors in preterm neonates with probable transitional circulatory instability in the first week of life: a systematic review and network meta-analysis

BACKGROUND

There exists limited agreement on the recommendations for the treatment of transitional circulatory instability (TCI) in preterm neonates OBJECTIVE: To compare the efficacy of various interventions used to treat TCI METHODS: Medline and Embase were searched from inception to 21st July 2023. Two authors extracted the data independently. A Bayesian random effects network meta-analysis was used. Recommendations were formulated using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) framework.

INTERVENTIONS

Dopamine, dobutamine, epinephrine, hydrocortisone, vasopressin, milrinone, volume and placebo.

MAIN OUTCOME MEASURES

Mortality, major brain injury (MBI) (intraventricular haemorrhage > grade 2 or cystic periventricular leukomalacia), necrotising enterocolitis (NEC) ≥stage 2 and treatment response (as defined by the author).

RESULTS

15 Randomized Controlled Trials (RCTs) were included from the 1365 titles and abstracts screened. Clinical benefit or harm could not be ruled out for the critical outcome of mortality. For the outcome of MBI, epinephrine possibly decreased the risk when compared to dobutamine and milrinone (very low certainty). Epinephrine was possibly associated with a lesser risk of NEC when compared with dopamine, dobutamine, hydrocortisone and milrinone (very low certainty). Dopamine was possibly associated with a lesser risk of NEC when compared with dobutamine (very low certainty). Vasopressin possibly decreased the risk of NEC compared with dopamine, dobutamine, hydrocortisone and milrinone (very low certainty). Clinical benefit or harm could not be ruled out for the outcome response to treatment.

CONCLUSIONS

Epinephrine may be used as the first-line drug in preterm neonates with TCI, the evidence certainty being very low. We suggest future trials evaluating the management of TCI with an emphasis on objective criteria to define it.

An Update on Pharmacologic Management of Neonatal Hypotension: When, Why, and Which Medication

Anti-hypotensive treatment, which includes dopamine, dobutamine, epinephrine, norepinephrine, milrinone, vasopressin, terlipressin, levosimendan, and glucocorticoids, is a long-established intervention in neonates with arterial hypotension (AH). However, there are still gaps in knowledge and issues that need clarification. The main questions and challenges that neonatologists face relate to the reference ranges of arterial blood pressure in presumably healthy neonates in relation to gestational and postnatal age; the arterial blood pressure level that potentially affects perfusion of critical organs; the incorporation of targeted echocardiography and near-infrared spectroscopy for assessing heart function and cerebral perfusion in clinical practice; the indication, timing, and choice of medication for each individual patient; the limited randomized clinical trials in neonates with sometimes conflicting results; and the sparse data regarding the potential effect of early hypotension or anti-hypotensive medications on long-term neurodevelopment. In this review, after a short review of AH definitions used in neonates and existing data on pathophysiology of AH, we discuss currently available data on pharmacokinetic and hemodynamic effects, as well as the effectiveness and safety of anti-hypotensive medications in neonates. In addition, data on the comparisons between anti-hypotensive medications and current suggestions for the main indications of each medication are discussed.

Analysis of trends in retinopathy of prematurity over 5 years in a tertiary neonatal intensive care unit

AIM

The aim of the study was to look at the incidence and trend of retinopathy of prematurity (ROP) between 2017 and 2021 in a tertiary neonatal intensive care unit (NICU) in Australia and to compare potential modifiable risk factors of ROP between preterm infants who required treatment for ROP and who did not need treatment.

METHODS

This retrospective study used the data of newborn infants who were <31 weeks gestational age (GA) or birth weight (BW) of <1250 g born between 2017 and 2021 at a tertiary NICU in Australia (n = 261). Univariate analysis using t test for continuous data, Fischer exact test for categorical data and multiple logistic regression analysis were undertaken to identify any significant differences between two groups.

RESULTS

A total number of 261 infants were studied. 55.9% of infants developed any type of ROP (146 infants out of 261 infants), type 1 ROP was 5.4% (14 out of 261) and aggressive ROP (AROP) was 3% (8 out of 261). Out of 146 infants who were diagnosed with ROP, 22 (15%) of them required treatment. Mean GA for those who underwent ROP treatment was 25.6 (±1.47) weeks and for those who did not require treatment was 27.6 (±1.95) weeks. The mean BWs for those who needed treatment was 764 (±189.32) g and for those who did not need treatment was 1039 (±306.06) g. The mean duration of invasive ventilation for infants with ROP requiring treatment and those who did not require treatment were 23.95 (±22.41) days and 9.89 (±17.2) days. The total duration of oxygen requirement was 235.54 (±160.5) days and 121.11 (±117.34) days for those who needed treatment and those who did not need treatment respectively. Among infants who required treatment for ROP, 68.18% required blood transfusion whereas among those who did not need treatment, 24.19% required blood transfusion.

CONCLUSION

Lower GA, lower BW, longer duration of invasive ventilation, longer total duration of oxygen requirement and blood transfusion in first 2 weeks of life were significant in preterm infants who required treatment for ROP compared with those who did not.

Efficacy of dopamine, epinephrine and blood transfusion for treatment of fluid refractory shock in children with severe acute malnutrition or severe underweight and cholera or other dehydrating diarrhoeas: protocol for a randomised controlled clinical trial

INTRODUCTION

Diarrhoea is one of the leading causes of under-5 childhood mortality and accounts for 8% of 5.4 million global under-5 deaths. In severely malnourished children, diarrhoea progresses to shock, where the risk of mortality is even higher. At icddr,b Dhaka Hospital, the fatality rate is as high as 69% in children with severe malnutrition and fluid refractory septic shock. To date, no study has evaluated systematically the effects of inotrope or vasopressor or blood transfusion in children with dehydrating diarrhoea (eg, in cholera) and severe acute malnutrition (SAM) or severe underweight who are in shock and unresponsive to WHO-recommended fluid therapy. To reduce the mortality of severely malnourished children presenting with diarrhoea and fluid refractory shock, we aim to compare the efficacy of blood transfusion, dopamine and epinephrine in fluid refractory shock in children who do not respond to WHO-recommended fluid resuscitation.

METHODS AND ANALYSIS

In this randomised, three-arm, controlled, non-masked clinical trial in children 1-59 months old with SAM or severe underweight and fluid refractory shock, we will compare the efficacy of dopamine or epinephrine administration versus blood transfusion in children who failed to respond to WHO-recommended fluid resuscitation. The primary outcome variable is the case fatality rate. The effect of the intervention will be assessed by performing an intention-to-treat analysis. Recruitment and data collection began in July 2021 and are now ongoing. Results are expected by May 2023.

ETHICS AND DISSEMINATION

This study has been approved by the icddr,b Institutional Review Board. We adhere to the 'Declaration of Helsinki' (2000), guidelines for Good Clinical Practice. Before enrolment, we collect signed informed consent from the parents or caregivers of the children. We will publish the results in a peer-reviewed journal and will arrange a dissemination seminar.

TRIAL REGISTRATION NUMBER

NCT04750070.

Interventions to Reduce Severe Brain Injury Risk in Preterm Neonates: A Systematic Review and Meta-analysis

Importance

Interventions to reduce severe brain injury risk are the prime focus in neonatal clinical trials.

Objective

To evaluate multiple perinatal interventions across clinical settings for reducing the risk of severe intraventricular hemorrhage (sIVH) and cystic periventricular leukomalacia (cPVL) in preterm neonates.

Data Sources

MEDLINE, Embase, CENTRAL (Cochrane Central Register of Controlled Trials), and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases were searched from inception until September 8, 2022, using prespecified search terms and no language restrictions.

Study Selection

Randomized clinical trials (RCTs) that evaluated perinatal interventions, chosen a priori, and reported 1 or more outcomes (sIVH, cPVL, and severe brain injury) were included.

Data Extraction and Synthesis

Two co-authors independently extracted the data, assessed the quality of the trials, and evaluated the certainty of the evidence using the Cochrane GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Fixed-effects pairwise meta-analysis was used for data synthesis.

Main Outcomes and Measures

The 3 prespecified outcomes were sIVH, cPVL, and severe brain injury.

Results

A total of 221 RCTs that assessed 44 perinatal interventions (6 antenatal, 6 delivery room, and 32 neonatal) were included. Meta-analysis showed with moderate certainty that antenatal corticosteroids were associated with small reduction in sIVH risk (risk ratio [RR], 0.54 [95% CI, 0.35-0.82]; absolute risk difference [ARD], -1% [95% CI, -2% to 0%]; number needed to treat [NNT], 80 [95% CI, 48-232]), whereas indomethacin prophylaxis was associated with moderate reduction in sIVH risk (RR, 0.64 [95% CI, 0.52-0.79]; ARD, -5% [95% CI, -8% to -3%]; NNT, 20 [95% CI, 13-39]). Similarly, the meta-analysis showed with low certainty that volume-targeted ventilation was associated with large reduction in risk of sIVH (RR, 0.51 [95% CI, 0.36-0.72]; ARD, -9% [95% CI, -13% to -5%]; NNT, 11 [95% CI, 7-23]). Additionally, early erythropoiesis-stimulating agents (RR, 0.68 [95% CI, 0.57-0.83]; ARD, -3% [95% CI, -4% to -1%]; NNT, 34 [95% CI, 22-67]) and prophylactic ethamsylate (RR, 0.68 [95% CI, 0.48-0.97]; ARD, -4% [95% CI, -7% to 0%]; NNT, 26 [95% CI, 13-372]) were associated with moderate reduction in sIVH risk (low certainty). The meta-analysis also showed with low certainty that compared with delayed cord clamping, umbilical cord milking was associated with a moderate increase in sIVH risk (RR, 1.82 [95% CI, 1.03-3.21]; ARD, 3% [95% CI, 0%-6%]; NNT, -30 [95% CI, -368 to -16]).

Conclusions and Relevance

Results of this study suggest that a few interventions, including antenatal corticosteroids and indomethacin prophylaxis, were associated with reduction in sIVH risk (moderate certainty), and volume-targeted ventilation, early erythropoiesis-stimulating agents, and prophylactic ethamsylate were associated with reduction in sIVH risk (low certainty) in preterm neonates. However, clinicians should carefully consider all of the critical factors that may affect applicability in these interventions, including certainty of the evidence, before applying them to clinical practice.

Use of Vasopressors in Extremely Preterm Infants in First Week of Life

OBJECTIVE

 A significant variability exists for diagnosis and treatment of hypotension in extremely preterm infants. Benefits of the use of vasopressors remain unclear. We wanted to identify the risk factors associated with use of vasopressors in the first week of life and their impact on outcomes of extremely preterm infants.

STUDY DESIGN

 Retrospective review of all newborns ≤28 weeks of gestational age (GA) admitted in neonatal intensive care unit from October 1, 2012, to October 31, 2015, done. Data regarding antenatal and neonatal characteristics and outcomes were recorded. Study infants were divided into two cohorts and compared based on vasopressor use. Chi-square, t-test, and multiple logistic regression were performed as appropriate and significance set at p <0.05.

RESULTS

 Of 213 extremely preterm infants, 90 (42.3%) received vasopressors in first week of life. The mean arterial pressure (MAP) at admission in these infants was significantly lower than that of infants who did not require vasopressors (27 ± 8 vs. 30 ± 6 mm Hg, p < 0.05). Vasopressors were initiated within 24 hours in 91% of babies. After controlling for other variables, use of vasopressors was significantly higher in infants with lower birth weight (odds ratio [OR]: 3.2, 95% confidence interval [CI]: 1.6-8.3), 5-minute Apgar's score ≤5 (OR: 1.8, 95% CI: 1.2-3.12), and admission hypothermia (OR: 2.7, 95% CI: 1.3-4.9). The use of vasopressors was significantly associated with severe intraventricular hemorrhage (IVH), even after controlling for other significant variables (OR: 5.9, 95% CI: 1.6-9.3).

CONCLUSION

 Lower birth weight, low 5-minute Apgar's score, and admission hypothermia are characteristics associated with early use of vasopressors in extremely preterm infants. Infants treated with vasopressors are at a higher risk of developing severe IVH.

KEY POINTS

· Low systemic blood pressure is a very common problem in the extremely preterm population.. · In clinical practice, mean arterial blood pressure (BP) less than the infants GA in week is typically considered to be "low BP.". · About 50% of infants born at <29 weeks of GA received very preterm in the first week of life.. · Use of vasopressors is associated with a higher incidence of intraventricular hemorrhage in extremely preterm population..

Systematic Review and Meta-Analysis of Cardiovascular Medications in Neonatal Hypotension

Background

Comparative studies among the various cardiovascular medications used for the treatment of neonatal hypotension are lacking.

Methods

This systematic review and pairwise meta-analysis of the anti-hypotensive treatments in preterm and term infants was conducted to evaluate efficacy and impact on outcome. Electronic databases were searched up to February 2021 for relevant articles. As an extension of the current approach for study selection, a machine learning technique was used. Only randomized controlled trials (RCTs) of inotropes, pressors, volume therapy, and corticosteroids were included. Response to treatment was the primary outcome while secondary outcomes included mortality and common morbidities.

Results

Nineteen RCTs involving 758 preterm and term neonates were found, and 8 treatments were evaluated. Most studies involved subjects with early hypotension associated with prematurity. Pairwise meta-analysis among treatments showed that dopamine was more effective than dobutamine regarding the response to treatment (restoration of normotension or normalization of blood pressure) (7 trials, 286 neonates, odds ratio, 3.06 [95% CI = 1.06–8.87]; I² = 49%, very low quality of the evidence per GRADE). Comparisons of other treatments were not significant. No differences were found among regimens regarding survival and other secondary outcomes.

Conclusion

In this systematic review and pairwise meta-analysis, only the comparison of dopamine versus dobutamine provided evidence for efficacy of treatment and favored dopamine. No safe conclusions could be reached in regard to other treatments. Data regarding the management of arterial hypotension in conditions other than transition after birth in preterm newborns are sparse both in preterm and term infants.

Successful use of an artificial placenta-based life support system to treat extremely preterm ovine fetuses compromised by intrauterine inflammation

BACKGROUND

Ex vivo uterine environment therapy is an experimental intensive care strategy for extremely preterm infants born between 21 and 24 weeks of gestation. Gas exchange is performed by membranous oxygenators connected by catheters to the umbilical vessels. The fetus is submerged in a bath of synthetic amniotic fluid. The lungs remain fluid filled, and pulmonary respiration does not occur. Intrauterine inflammation is strongly associated with extremely preterm birth and fetal injury. At present, there are no data that we are aware of to show that artificial placenta-based systems can be used to support extremely preterm fetuses compromised by exposure to intrauterine inflammation.

OBJECTIVE

To evaluate the ability of our ex vivo uterine environment therapy platform to support extremely preterm ovine fetuses (95-day gestational age; approximately equivalent to 24 weeks of human gestation) exposed to intrauterine inflammation for a period of 120 hours, the following primary endpoints were chosen: (1) maintenance of key physiological variables within normal ranges, (2) absence of infection and inflammation, (3) absence of brain injury, and (4) gross fetal growth and cardiovascular function matching that of age-matched in utero controls.

STUDY DESIGN

Ten ewes with singleton pregnancies were each given a single intraamniotic injection of 10-mg Escherichia coli lipopolysaccharides under ultrasound guidance 48 hours before undergoing surgical delivery for adaptation to ex vivo uterine environment therapy at 95-day gestation (term=150 days). Fetuses were adapted to ex vivo uterine environment therapy and maintained for 120 hours with constant monitoring of key vital parameters (ex vivo uterine environment group) before being killed at 100-day equivalent gestational age. Umbilical artery blood samples were regularly collected to assess blood gas data, differential counts, biochemical parameters, inflammatory markers, and microbial load to exclude infection. Ultrasound was conducted at 48 hours after intraamniotic lipopolysaccharides (before surgery) to confirm fetal viability and at the conclusion of the experiments (before euthanasia) to evaluate cardiac function. Brain injury was evaluated by gross anatomic and histopathologic investigations. Eight singleton pregnant control animals were similarly exposed to intraamniotic lipopolysaccharides at 93-day gestation and were killed at 100-day gestation to allow comparative postmortem analyses (control group). Biobanked samples from age-matched saline-treated animals served as an additional comparison group. Successful instillation of lipopolysaccharides into the amniotic fluid exposure was confirmed by amniotic fluid analysis at the time of administration and by analyzing cytokine levels in fetal plasma and amniotic fluid. Data were tested for mean differences using analysis of variance.

RESULTS

Six of 8 lipopolysaccharide control group (75%) and 8 of 10 ex vivo uterine environment group fetuses (80%) successfully completed their protocols. Six of 8 ex vivo uterine environment group fetuses required dexamethasone phosphate treatment to manage profound refractory hypotension. Weight and crown-rump length were reduced in ex vivo uterine environment group fetuses at euthanasia than those in lipopolysaccharide control group fetuses (P<.05). There were no biologically significant differences in cardiac ultrasound measurement, differential leukocyte counts (P>.05), plasma tumor necrosis factor α, monocyte chemoattractant protein-1 concentrations (P>.05), or liver function tests between groups. Daily blood cultures were negative for aerobic and anaerobic growth in all ex vivo uterine environment group animals. No cases of intraventricular hemorrhage were observed. White matter injury was identified in 3 of 6 lipopolysaccharide control group fetuses and 3 of 8 vivo uterine environment group fetuses.

CONCLUSION

We report the use of an artificial placenta-based system to support extremely preterm lambs compromised by exposure to intrauterine inflammation. Our data highlight key challenges (refractory hypotension, growth restriction, and white matter injury) to be overcome in the development and use of artificial placenta technology for extremely preterm infants. As such challenges seem largely absent from studies based on healthy pregnancies, additional experiments of this nature using clinically relevant model systems are essential for further development of this technology and its eventual clinical application.

What Inotrope and Why?

Primary function of cardiovascular system is to meet body's metabolic demands. The aim of inotrope therapy is to minimise adverse impact of cardiovascular compromise. Current use of inotropes is primarily guided by the pathophysiology of cardiovascular compromise and anticipated actions of inotropes. Lack of significant reduction in morbidity and mortality associated with cardiovascular compromise despite inotrope use, highlights major gaps in our understanding of circulatory targets, thresholds and choices of inotrope therapy. Thus far, prevention of cardiovascular compromise remains the most effective strategy to optimize outcomes. Studies of alternative design are needed for further advancement in cardiovascular therapy in neonates.

Clinical Trials in Hemodynamic Support: Past, Present, and Future

Managing low blood flow states in the preterm population remains a challenge in neonatal clinical care. The heterogeneity of the trials to date and the relatively low number of infants enrolled, in addition to a desire to oversimplify the underlying pathophysiology, have contributed to an inability to draw meaningful conclusions to direct clinical care. This article reviews the current literature on this topic in the preterm population and outlines the challenges that have been encountered in performing such trials. Alternative studies are proposed, based on the lessons learned over the past number of years.

Successful use of an artificial placenta to support extremely preterm ovine fetuses at the border of viability

BACKGROUND

Ex vivo uterine environment therapy is an experimental life support platform designed to reduce the risk of morbidity and mortality for extremely preterm infants born at the border of viability (21-24 weeks' gestation). To spare the functionally immature lung, this platform performs gas exchange via a membranous oxygenator connected to the umbilical vessels, and the fetus is submerged in a protective bath of artificial amniotic fluid. We and others have demonstrated the feasibility of extended survival with ex vivo uterine environment therapy therapy in late preterm fetuses; however, there is presently no evidence to show that the use of such a platform can support extremely preterm fetuses, the eventual translational target for therapy of this nature.

OBJECTIVE

The objective of the study was to use our ex vivo uterine environment therapy platform to support the healthy maintenance of 600-700 g/95 days gestational age (equivalent to 24 weeks of human gestation) sheep fetuses. Primary outcome measures were as follows: (1) maintenance of key physiological variables; (2) absence of infection; (3) absence of brain injury; and (4) growth and cardiovascular function patterns matching that of noninstrumented, age-matched in utero controls.

STUDY DESIGN

Singleton fetuses from 8 ewes underwent surgical delivery at 95 days' gestation (term, 150 days). Fetuses were adapted to ex vivo uterine environment therapy and maintained for 120 hours with real-time monitoring of key physiological variables. Umbilical artery blood samples were regularly collected to assess blood gas data, differential counts, inflammation, and microbial load to exclude infection. Brain injury was evaluated by gross anatomical and histopathological approaches after euthanasia. Nine pregnant control animals were euthanized at 100 days' gestation to allow comparative postmortem analyses. Data were tested for mean differences with an analysis of variance.

RESULTS

Seven of 8 ex vivo uterine environment group fetuses (87.5%) completed 120 hours of therapy with key parameters maintained in a normal physiological range. There were no significant intergroup differences (P > .05) in final weight, crown-rump length, and body weight-normalized lung and brain weights at euthanasia compared with controls. There were no biologically significant differences in hematological parameters (total or differential leucocyte counts and plasma concentration of tumor necrosis factor-α and monocyte chemoattractant protein 1) (P > .05). Daily blood cultures were negative for aerobic and anaerobic growth in all ex vivo uterine environment animals. There was no difference in airspace consolidation between control and ex vivo uterine environment animals, and there was no increase in the number of lung cells staining positive for the T-cell marker CD3. There were no increases in interleukin-1, interleukin-6, interleukin-8, tumor necrosis factor-α, and monocyte chemoattractant protein 1 mRNA expression in lung tissues compared with the control group. No cases of intraventricular hemorrhage were observed, and white matter injury was identified in only 1 ex vivo uterine environment fetus.

CONCLUSION

For several decades, there has been little improvement in outcomes of extremely preterm infants born at the border of viability. In the present study, we report the use of artificial placenta technology to support, for the first time, extremely preterm ovine fetuses (equivalent to 24 weeks of human gestation) in a stable, growth-normal state for 120 hours. With additional refinement, the data generated by this study may inform a treatment option to improve outcomes for extremely preterm infants.

Early red cell transfusion is associated with development of severe retinopathy of prematurity

OBJECTIVE

To evaluate the association between early (within 10 d) pRBC transfusion and the development of severe ROP.

STUDY DESIGN AND METHODS

This was a single-center retrospective study. Inclusion criteria were preterm infants born ≤32 weeks gestation or weighing ≤1500 g. Severe ROP was defined as infants requiring retinal laser ablation or bevacizumab injection. Logistic regression was used to identify the association between transfusions and severe ROP.

RESULTS

A total of 1635 infants were included in the final analysis. The severe ROP incidence was 8% (126/1635). Ninety-one percent (115/126) of infants who developed severe ROP received a pRBC transfusion in the first 10 d. Early transfusion was associated with severe ROP; adjusted odds ratio of 3.8 (95% CI: 1.8-8.1).

CONCLUSION

pRBC transfusions in the first 10 days of life are associated with an almost four-fold increased risk of severe ROP, independent of gestational age at birth or bronchopulmonary dysplasia (BPD) status.

Hypotension within 1 week of life associated with poor short- and long-term outcomes in very low birth weight infants

We examined whether hypotension in very low birth weight infants aged⩽1 week was associated with hospital morbidities and overall mortality. Further, we studied whether hypotension was associated with poor neurodevelopmental outcomes in these patients at the corrected age of 18 months. A total of 166 very low birth weight infants were studied during this period. Hospital outcomes and neurodevelopmental outcomes at the corrected age of 18 months were evaluated. Among the 166 very low birth weight infants, 95 patients (57.2%) experienced hypotension at⩽1 week and were associated with an increased incidence of morbidities and mortality. At the corrected age of 18 months, hypotension of the⩽1 week group had significantly lower scores in all three - cognitive, language, and motor - composites of the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) screening tests. In addition, a multivariable logistic regression analysis showed that longer mechanical ventilation and periventricular leukomalacia were additionally associated with worse cognitive and language neurodevelopmental outcomes. Hypotension in very low birth weight infants within 1 week of life was associated with increased morbidities and overall mortality. It was also associated with an increased risk of cognitive and language outcomes.

Inotropes for Preterm Infants: 50 Years on Are We Any Wiser?

For almost half a century, inotropes have been administered to preterm infants with the ultimate goal of increasing their blood pressure. A number of trials, the majority of which focused on dopamine administration, have demonstrated increased blood pressure following inotrope administration in preterm infants and have led to continued use of inotropes in our neonatal units. We have also seen an increase in the number of potential agents available to the clinician. However, we now know that hypotension is a much broader concept than blood pressure alone, and our aim should instead be focused on improving end organ perfusion, specifically cerebral perfusion. Only a limited number of studies have incorporated the organ-relevant hemodynamic changes and long-term outcomes when assessing inotropic effects in neonates, the majority of which are observational studies or have a small sample size. In addition, important considerations, including the developing/maturing adrenergic receptors, polymorphisms of these receptors, and other differences in the pharmacokinetics and pharmacodynamics of preterm infants, are only recently being recognized. Certainly, there remains huge variation in practice. The lack of well-conducted randomized controlled trials addressing these relevant outcomes, along with the difficulty executing such RCTs, leaves us with more questions than answers. This review provides an overview of the various inotropic agents currently being used in the care of preterm infants, with a particular focus on their organ/cerebral hemodynamic effects both during and after transition.

A comparative analysis of ante- and postnatal clinical characteristics of extremely premature neonates suffering from refractory and non-refractory hypotension: Is early clinical differentiation possible?

BACKGROUND

About 25% of hypotensive ELBW infants are refractory to intravascular volume expansion and inotropic drugs (VI) and require hydrocortisone (HC). Such neonates suffer from complications of prolonged hypotension and extended therapy with VI. ELBW infants with refractory hypotension (RH) are clinically and biochemically indistinguishable from those who respond to VI.

OBJECTIVE

Early identification and differentiation of ELBW infants susceptible to steroid dependent hypotension from those who respond to inotropic medications.

METHODS

In a retrospective study the ante- and postnatal clinical characteristics of ELBW infants who received hydrocortisone (HC) for refractory hypotension (RH) were compared to those who responded to volume-inotropes (VI).

RESULTS

Infants in HC group had lower birth weight (BW, 675±121g) and gestational age (GA, 25.1±1.3weeks) and higher mean airway pressure and oxygen requirements, all independent of antenatal steroid (ANS) exposure. The receipt of ANS (p 0.01) and occurrences of maternal diabetes mellitus (GDM, p 0.01) were lower in HC group. ANS (OR 0.5, 95% CI 0.2-0.9, p 0.01) and GDM (OR 0.3, 95% CI 0.09-0.9, p 0.04) reduced the risk for RH. HC group had higher risk for IVH (OR 2.1, 95% CI 1.02-4.2 p=0.04) which declined in the multivariate analysis. A trend towards lower risk of ventriculomegaly (VM) was noted in HC group (OR 0.3, 95% CI 0.1-1.1), which became significant after controlling for BW (OR 0.2 95% CI 0.07-0.9, p 0.04). Similar trend was noted for maternal hypertension.

CONCLUSION

Hypotension in ELBW infants who are ≤25wks of GA and unexposed to ANS and GDM is refractory to VI therapy. Such neonates may benefit from an initial therapy with, or earlier institution of hydrocortisone. The trend towards a higher risk for VM with VI therapy needs validation in future studies.

Uses and misuses of albumin during resuscitation and in the neonatal intensive care unit

Albumin is one of the most abundant proteins in plasma and serves many vital functions. Neonatal concentrations vary greatly with gestational and postnatal age. In critically ill neonates, hypoalbuminemia occurs due to decreased synthesis, increased losses or redistribution of albumin into the extravascular space, and has been associated with increased morbidities and mortality. For that reason, infusion of exogenous albumin as a volume expander has been proposed for various clinical settings including hypotension, delivery room resuscitation, sepsis and postoperative fluid management. Albumin is often prescribed in infants with hypoalbuminemia, hyperbilirubinemia, and protein-losing conditions. However, the evidence of these practices has not been reviewed or validated. Albumin infusion may initiate highly complex processes that vary according to the individual and disease pathophysiology. Indeed, it may be associated with harms when misused. In this review, we critically appraise the scientific evidence for administering albumin in most conditions encountered in the neonatal intensive care unit, while emphasizing the benefits and risks associated with their use.

Response to dopamine in prematurity: a biomarker for brain injury?

OBJECTIVE

To identify factors associated with responsiveness to dopamine therapy for hypotension and the relationship to brain injury in a cohort of preterm infants.

STUDY DESIGN

The pharmacy database at St Louis Children's Hospital was retrospectively queried to identify infants who (a) were born <28 weeks gestation between 2012 and 2014, (b) received dopamine and (c) had blood pressure measurements from an umbilical arterial catheter. A control group was constructed from contemporaneous infants who did not receive dopamine. Mean arterial blood pressure (MABP) at baseline, 1 h and 3 h after initiating dopamine were obtained for each dopamine-exposed infant. MABP measurements at matched time points were obtained in the control group.

RESULT

Sixty-nine dopamine-treated and 45 control infants were included. Mean ΔMABP at 3 h was 4.5±6.3 mm of Hg for treated infants vs 1±2.9 for the control. Median dopamine starting dose was 2.5 μg kg(-1) min(-1). Dopamine-treated infants were less mature and of lower birth weight while also more likely to be intubated at 72 h, diagnosed with intraventricular hemorrhage (IVH) and to die. Failure to respond to dopamine was associated with greater likelihood of developing IVH (odds ratio (OR) 5.8, 95% confidence interval (CI) 1.1-42.3), while a strong response (ΔMABP>10 mm Hg) was associated with a reduction in risk of IVH (OR 0.1, 95% CI 0.01-0.8).

CONCLUSION

Low-moderate dose dopamine administration results in modest blood pressure improvements. A lack of response to dopamine is associated with a greater risk of IVH, whereas a strong response is associated with a decreased risk. Further research into underlying mechanisms and management strategies is needed.

Diagnosis and management of hypotension in neonates

The diagnosis and management of hypotension in neonates is a frequently encountered issue in the intensive care setting. There is an ongoing debate as to the appropriateness of blood pressure monitoring as an indicator of organ perfusion and tissue hypoxia. These ultimately determine morbidity and mortality in the sick newborn. This article explores the methods available for the assessment of organ perfusion and speculates on other means that may become available in the future. Different modalities of treatment currently in use are discussed, with the aim of using information gained from perfusion monitoring techniques to determine the optimal choice of therapy.

Challenges in understanding the impact of blood pressure management on cerebral oxygenation in the preterm brain

Systemic hypotension in preterm infants has been related to increased mortality, cerebrovascular lesions, and neurodevelopmental morbidity. Treatment of hypotension with inotropic medications aims at preservation of end organ perfusion and oxygen delivery, especially the brain. The common inotropic medications in preterm infants include dopamine, dobutamine, adrenaline, with adjunctive use of corticosteroids in cases of refractory hypotension. Whether maintenance of mean arterial blood pressure (MAP) by use of inotropic medication is neuroprotective or not remains unclear. This review explores the different inotropic agents and their effects on perfusion and oxygenation in the preterm brain, in clinical studies as well as in animal models. Dopamine and adrenalin, because of their α-adrenergic vasoconstrictor actions, have raised concerns of reduction in cerebral blood flow (CBF). Several studies in hypotensive preterm infants have shown that dopamine elevates CBF together with increased MAP, in keeping with limited cerebro-autoregulation. Adrenaline is also effective in raising cerebral perfusion together with MAP in preterm infants. Experimental studies in immature animals show no cerebro-vasoconstrictive effects of dopamine or adrenaline, but demonstrate the consistent findings of increased cerebral perfusion and oxygenation with the use of dopamine, dobutamine, and adrenaline, alongside with raised MAP. Both clinical and animal studies report the transitory effects of adrenaline in increasing plasma lactate, and blood glucose, which might render its use as a 2nd line therapy. To investigate the cerebral effects of inotropic agents in long-term outcome in hypotensive preterm infants, carefully designed prospective research possibly including preterm infants with permissive hypotension is required. Preterm animal models would be useful in investigating the relationship between the physiological effects of inotropes and histopathology outcomes in the developing brain.

Permissive hypotension in extremely low birth weight infants (≤1000 gm)

PURPOSE

We performed this study to evaluate the safety of permissive hypotension management in extremely low birth weight infants (ELBWIs).

MATERIALS AND METHODS

Medical records of all inborn ELBWIs admitted to Samsung Medical Center from January 2004 to December 2008 were reviewed retrospectively. Of a total of 261 ELBWIs, 47 (18%) required treatment for hypotension (group T), 110 (42%) remained normotensive (group N), and 104 (40%) experienced more than one episode of hypotension without treatment (group P) during the first 72 hours of life. Treatment of hypotension included inotropic support and/or fluid loading.

RESULTS

Birth weight and Apgar scores were significantly lower in the T group than the other two groups. In the N group, the rate of pathologically confirmed maternal chorioamnionitis was significantly higher than other two groups, and the rate was higher in the P group than the T group. After adjusting for covariate factors, no significant differences in mortality and major morbidities were found between the N and P groups. However, the mortality rate and the incidence of intraventricular hemorrhage (≥stage 3) and bronchopulmonary dysplasia (≥moderate) were significantly higher in the T group than the other two groups. Long term neurodevelopmental outcomes were not significantly different between the N and P groups.

CONCLUSION

Close observation of hypotensive ELBWIs who showed good clinical perfusion signs without intervention allowed to avoid unnecessary medications and resulted in good neurological outcomes.

Pediatric Sepsis - Part I: "Children are not small adults!"

The recognition, diagnosis, and management of sepsis remain among the greatest challenges in pediatric critical care medicine. Sepsis remains among the leading causes of death in both developed and underdeveloped countries and has an incidence that is predicted to increase each year. Unfortunately, promising therapies derived from preclinical models have universally failed to significantly reduce the substantial mortality and morbidity associated with sepsis. There are several key developmental differences in the host response to infection and therapy that clearly delineate pediatric sepsis as a separate, albeit related, entity from adult sepsis. Thus, there remains a critical need for well-designed epidemiologic and mechanistic studies of pediatric sepsis in order to gain a better understanding of these unique developmental differences so that we may provide the appropriate treatment. Herein, we will review the important differences in the pediatric host response to sepsis, highlighting key differences at the whole-organism level, organ system level, and cellular and molecular level.

A meta-analysis of dopamine use in hypotensive preterm infants: blood pressure and cerebral hemodynamics

OBJECTIVE

Dopamine administration results in variable effects on blood pressure in hypotensive preterm infants. The clinical benefits of dopamine administration in increasing cerebral blood flow (CBF) and reducing adverse neurological outcomes in hypotensive preterm neonates are unclear. The objective of this study was to examine the efficacy of dopamine for treatment of hypotension and investigate the changes in cerebral hemodynamics and central nervous system injury in hypotensive preterm infants following dopamine administration.

STUDY DESIGN

Standard meta-analytic techniques, including random and fixed effects models, were used to calculate combined effect size correlations and significance levels.

RESULT

Random effects meta-analysis found that dopamine increases mean arterial blood pressure (12 studies; N=163; r=0.88, 95% confidence interval (CI)=0.76 to 0.94) and systolic blood pressure (8 studies; N=142; r=0.81, 95% CI=0.42 to 0.94). For the increase in blood pressure, dopamine administration was associated with a significantly greater overall efficacy than dobutamine (seven studies; N=251; r=0.26; 95% CI=0.20 to 0.32), colloid (two studies; N=67; r=0.60; 95% CI=0.41 to 0.74) and hydrocortisone (one study; N=28; r=0.40; 95% CI=0.034 to 0.67). CBF increased following dopamine administration (five studies; N=75; r=0.36; 95% CI=-0.059 to 0.67) and the increase in CBF was greater in hypotensive than normotensive preterm infants (eight studies; N=153; r=0.16; 95% CI=-0.0080 to 0.32). There were no statistically significant differences in adverse neurological outcome between dopamine and dobutamine (three studies; N=118; r=-0.13; 95% CI=-0.31 to 0.059), epinephrine (two studies; N=46; r=0.06; 95% CI=-0.23 to 0.34), colloid (two studies; N=80; r=0.0070; 95% CI=-0.218 to 0.23) or hydrocortisone administration (one study; N=40; r=-0.10; 95% CI=-0.40 to 0.22).

CONCLUSION

Dopamine administration increases mean and systolic blood pressure in hypotensive preterm infants, and is more effective than dobutamine, colloid or hydrocortisone alone. Dopamine administration is associated with increased CBF, with greater increases in CBF in hypotensive than in normotensive preterm infants. Dopamine is not associated with a greater incidence of adverse effects than other therapies used to treat hypotension.

The role of systemic hemodynamic disturbances in prematurity-related brain injury

Premature infants who experience cerebrovascular injury frequently have acute and long-term neurologic complications. In this article, we explore the relationship between systemic hemodynamic insults and brain injury in this patient population and the mechanisms that might be at play.

Cerebrovascular injury in premature infants: current understanding and challenges for future prevention

Cerebrovascular insults are a leading cause of brain injury in premature infants, contributing to the high prevalence of motor, cognitive, and behavioral deficits. Understanding the complex pathways linking circulatory immaturity to brain injury in premature infants remains incomplete. These mechanisms are significantly different from those causing injury in the mature brain. The gaps in knowledge of normal and disturbed cerebral vasoregulation need to be addressed. This article reviews current understanding of cerebral perfusion, in the sick premature infant in particular, and discusses challenges that lie ahead.

Dopamine versus dobutamine in very low birthweight infants: endocrine effects

OBJECTIVES

To compare the endocrine effects of dopamine and dobutamine in hypotensive very low birthweight (VLBW) infants.

DESIGN

Non-blinded randomised prospective trial.

SETTING

Level III neonatal intensive care unit.

PATIENTS

35 hypotensive VLBW infants who did not respond to volume loading, assigned to receive dopamine or dobutamine.

MEASUREMENTS

Haemodynamic variables and serum levels of thyroid stimulating hormone (TSH), total thyroxine (T(4)), prolactin (PRL) and growth hormone were assessed during the first 72 h of treatment and the first 72 h after stopping treatment.

RESULTS

Demographic and clinical data did not significantly differ between the two groups. Necessary cumulative and mean drug doses and maximum infusion required to normalise blood pressure were significantly higher in the dobutamine than in the dopamine group (p<0.01). Suppression of TSH, T(4) and PRL was observed in dopamine-treated newborns from 12 h of treatment onwards, whereas levels of growth hormone reduced significantly only at 12 h and 36 h of treatment (p<0.01). TSH, T(4) and PRL rebound was observed from the first day onwards after stopping dopamine. Dobutamine administration did not alter the profile of any of the hormones and no rebound was observed after stopping treatment.

CONCLUSION

Dopamine and dobutamine both increase the systemic blood pressure, though dopamine is more effective. Dopamine reduces serum levels of TSH, T(4) and PRL in VLBW infants but such suppression is quickly reversed after treatment is stopped. Further research is required to assess if short-term iatrogenic pituitary suppression has longer-term consequences.

Treating hypotension in the preterm infant: when and with what: a critical and systematic review

A very large proportion of extremely preterm infants receive treatments for hypotension. There are, however, marked variations in indications for treatment, and in the interventions used, between neonatal intensive care units and between neonatologists.

METHODS

We performed systematic reviews of the literature in order to determine which preterm infants may benefit from treatment with interventions to elevate blood pressure (BP), and which interventions improve clinically important outcomes.

RESULTS

Our review was not able to define a threshold BP that was significantly predictive of a poor outcome, nor whether any interventions for hypotensive infants improved outcomes, nor which interventions were more likely to be beneficial.

CONCLUSIONS

There is a distinct lack of prospective research of this issue, which prevents good clinical care. It is possible that a simple BP threshold that indicates the need for therapy does not exist, and other factors, such as the clinical status or systemic blood flow measurements, may be much more informative. Such a paradigm shift will also require careful prospective study.

The effect of inotropes on morbidity and mortality in preterm infants with low systemic or organ blood flow

BACKGROUND

Low systemic blood flow (SBF) is common in extremely premature infants in the first day after birth and has been associated with peri / intraventricular haemorrhage (PIVH), necrotising enterocolitis (NEC), mortality and developmental impairment.

OBJECTIVES

To determine the effect of specific inotropes on morbidity and mortality in preterm infants with low systemic blood flow

SEARCH STRATEGY

Searches were made of The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2006 ), MEDLINE (1966 - April 2006), EMBASE (1980 - April 2006) and CINAHL (1982 - April 2006), supplemented by searches of abstracts of conference proceedings, citations of reviews and expert informants.

SELECTION CRITERIA

Random and quasi-random controlled trials of inotropes enrolling preterm infants with low systemic or organ blood flow in the neonatal period.

DATA COLLECTION AND ANALYSIS

Independent assessment of trial eligibility, quality and data extraction by each review author. Synthesis of data using relative risk (RR) and weighted mean difference (WMD) using standard methods of the Cochrane Collaboration.

MAIN RESULTS

No studies that compared an inotrope to no treatment in preterm infants with low SBF were found. One study (Osborn 2002a) was found that compared dobutamine versus dopamine. The study was of adequate methodology. It enrolled 42 infants < 30 weeks gestation and < 12 hours after birth with low SVC flow. The trial compared the effect of dobutamine versus dopamine titrated 10 to 20 mug/kg/min with the goal of increasing and maintaining SVC flow > 40 ml/kg/min. No significant difference was reported in mortality to discharge (RR 1.41, 95% CI 0.79, 2.52), PIVH (RR 1.01, 95% 0.52, 1.97), grade 3 or 4 PIVH (RR 0.39, 95% CI 0.12, 1.31) or NEC. At three years, there was no significant difference in cerebral palsy, deafness, Developmental quotient > 2 sd below norm or combined disability (RR 0.10, 95% CI 0.01, 1.56). Surviving infants treated with dobutamine had a significantly higher development quotient (MD 35.00, 95% CI 17.68, 52.32). There was no significant difference in death or disability at the latest time reported (RR 0.95, 95% CI 0.66, 1.38). For secondary outcomes, there was no significant difference in periventricular leucomalacia, renal impairment, pulmonary haemorrhage, retinopathy of prematurity or CLD at 36 weeks. There was no significant difference in treatment failure. Dobutamine produced a significantly greater increase in SVC flow at the highest dose reached (MD 13.10, 95% CI 2.87, 23.33), whereas dopamine produced a significantly greater increase in mean BP at 10 and 20 mug/kg/min and at the highest dose reached (MD -7.20, 95% CI -11.41, -2.99).

AUTHORS' CONCLUSIONS

In preterm infants with low systemic blood flow, there is some evidence that dobutamine is better than dopamine at increasing and maintaining systemic blood flow. The only eligible trial did not demonstrate any consistent differences in clinical outcomes. However, this study was not sufficiently powered to prove or disprove effects on clinical outcomes. It is unclear what is the most effective strategy for improving the cardiovascular status of immature infants in the first day. Further trials are needed to determine effective strategies for preventing and improving low systemic and organ blood flow.

Hemodynamic changes after low-dosage hydrocortisone administration in vasopressor-treated preterm and term neonates

OBJECTIVE

We sought to investigate whether the increase in blood pressure and decrease in vasopressor support after hydrocortisone administration are associated with changes in systemic hemodynamics in neonates who receive high-dosage dopamine to maintain blood pressure at the lowest acceptable levels.

METHODS

In this prospective, observational study, preterm and term neonates who required dopamine > or = 15 microg/kg per minute to maintain minimum acceptable blood pressure received intravenous hydrocortisone 2 mg/kg followed by up to 4 doses of 1 mg/kg every 12 hours. Fifteen preterm and 5 term neonates without a patent ductus arteriosus composed the study population. Echocardiograms and vascular Doppler studies were performed immediately before the first dose of hydrocortisone and at 1, 2, 6 to 12, 24, and 48 hours thereafter.

RESULTS

In the 15 preterm infants, during the first 12 hours of hydrocortisone treatment, the 28% increase in blood pressure paralleled that in the systemic vascular resistance without changes in stroke volume or cardiac output, whereas dopamine dosage decreased. By 24 hours, the dosage of dopamine continued to decrease, whereas stroke volume increased without additional changes in systemic vascular resistance. By 48 hours, dopamine dosage decreased by 72%; blood pressure and stroke volume increased by 31% and 33%, respectively; and systemic vascular resistance and cardiac output tended to be higher (14% and 21%, respectively) compared with baseline. Contractility, global myocardial function, and Doppler indices of blood flow in the middle cerebral and renal artery remained normal and unchanged. The findings in the 5 term infants showed a similar pattern for changes in cardiac function, systemic hemodynamics, and organ blood flow after hydrocortisone administration.

CONCLUSIONS

In preterm and term neonates who require high-dosage dopamine to maintain blood pressure at the lowest acceptable levels, hydrocortisone improves blood pressure without compromising cardiac function, systemic perfusion, or cerebral and renal blood flow.

Cardiovascular support in preterm infants

BACKGROUND

Despite increasing investigation in the area of cardiovascular instability in preterm infants, huge gaps in knowledge remain. None of the current treatments for hypotension, including the use of inotropic agents, have been well studied in the preterm population, and data regarding safety and efficacy are lacking. Thus, the labeling information regarding the use of inotropes as therapeutic agents in this population is inadequate.

OBJECTIVE

This article reviews the current deficiencies in knowledge with respect to measuring and achieving normal organ perfusion; summarizes the clinical, methodological, and ethical issues to consider when designing trials to evaluate medications for hemodynamic instability in the preterm neonate; and proposes 2 possible trial designs. Unanswered questions and potential obstacles for the systematic study of drugs to treat cardiovascular instability in preterm neonates are discussed.

METHODS

The neonatal Cardiology Group was established in 2003 by the US Food and Drug Administration (FDA) and the National Institute of Child Health and Human Development (NICHD) as part of the Newborn Drug Development Initiative. The Cardiology Group conducted a number of teleconferences and one meeting to develop a document addressing gaps in knowledge regarding cardiovascular drugs commonly used in low-birth-weight neonates and possible approaches to investigate these drugs. This work was presented at a workshop cosponsored by the NICHD and the FDA held in March 2004 in Baltimore, Maryland. Information for this article was gathered during this initiative.

RESULTS

To develop rational, evidence-based guidelines corroborated by robust scientific data for cardiovascular support in newborns, well-designed and adequately powered pharmacologic studies and clinical trials are needed to evaluate the safety and efficacy of inotropic agents and to determine the short- and long-term effects of these drugs. Trials investigating the currently available and novel therapies for cardiovascular instability in neonates will provide information that can be incorporated into product labeling and a scientific framework for cardiovascular management in critically ill neonates. The Cardiology Group identified and prioritized 2 conditions for investigation of therapeutic options for the management of neonatal cardiovascular instability: (1) cardiovascular instability in preterm neonates; and (2) cardiac dysfunction in neonates after cardiopulmonary bypass surgery. Key research questions in the area of cardiovascular instability in the preterm infant include determining optimal blood pressure (BP) in preterm infants; identifying better measures than BP to determine organ perfusion; optimizing hemodynamic treatments; and clarifying any associations between BP or therapy for low BP and mortality, intraventricular hemorrhage, periventricular leukomalacia, necrotizing enterocolitis, retinopathy of prematurity, and neurodevelopmental outcome. The Cardiology Group concluded that the study of inotropic agents in neonates using outcomes of importance to patients will require a complicated trial design to address the elements discussed. The group proposed 2 clinical trial designs: (1) a placebo-controlled trial with rescue therapy for symptomatic infants; and (2) a targeted BP trial.

CONCLUSION

This summary is intended to stimulate and assist future research in the area of cardiovascular support for preterm infants.

Dopamine versus epinephrine for cardiovascular support in low birth weight infants: analysis of systemic effects and neonatal clinical outcomes

BACKGROUND

Early postnatal adaptation to transitional circulation in low birth weight infants frequently is associated with low blood pressure and decreased blood flow to organs. Catecholamines have been used widely as treatment, despite remarkably little empirical evidence on the effects of vasopressor/inotropic support on circulation and on clinically important outcomes in sick newborn infants.

AIMS

To explore the effectiveness of low/moderate-dose dopamine and epinephrine in the treatment of early systemic hypotension in low birth weight infants, evaluate the frequency of adverse drug effects, and examine neonatal clinical outcomes of patients in relation to treatment.

DESIGN/METHODS

Newborns of <1501-g birth weight or <32 weeks of gestational age, with a mean blood pressure lower than gestational age in the first 24 hours of life, were assigned randomly to receive dopamine (2.5, 5, 7.5, and 10 microg/kg per minute; n = 28) or epinephrine (0.125, 0.250, 0.375, and 0.5 microg/kg per minute; n = 32) at doses that were increased stepwise every 20 minutes until optimal mean blood pressure was attained and maintained (responders). If this treatment was unsuccessful (nonresponders), sequential rescue therapy was started, consisting first of the addition of the second study drug and then hydrocortisone.

OUTCOME MEASURES

These included: (1) short-term changes (first 96 hours, only responders) in heart rate, mean blood pressure, acid-base status, lactate, glycemia, urine output, and fluid-carbohydrate debit; and (2) medium-term morbidity, enteral nutrition tolerance, gastrointestinal complications, severity of lung disease, patent ductus arteriosus, cerebral ultrasound diagnoses, retinopathy of prematurity, and mortality.

RESULTS

Patients enrolled in this trial did not differ in birth weight or gestational age (1008 +/- 286 g and 28.3 +/- 2.3 weeks in the dopamine group; 944 +/- 281 g and 27.7 +/- 2.4 weeks in the epinephrine group). Other main antenatal variables were also comparable. However, responders and nonresponders differed significantly with respect to the need for cardiorespiratory resuscitation at birth (3% vs 23%), Critical Risk Index for Babies score (3.8 +/- 3 vs 7 +/- 5), and premature rupture of membranes >24 hours (39.5% vs 13.6%), respectively. No differences were found in the rate of treatment failure (dopamine: 36%; epinephrine: 37%) or need for rescue therapy according to treatment allocation. Groups did not differ in age at initiation of therapy (dopamine: 5.3 +/- 3.9 hours; epinephrine: 5.2 +/- 3.3 hours), but withdrawal was significantly later in the dopamine group. For short-term changes, mean blood pressure showed a significant increase from baseline throughout the first 96 hours with no differences between groups. However, epinephrine produced a greater increase in heart rate than dopamine. After treatment began, epinephrine patients showed higher plasma lactate (first 36 hours) and lower bicarbonate and base excess (first 6 hours) and received more bicarbonate. Patients in the epinephrine group also had higher glycemia (first 24 hours) and needed insulin therapy more often. Groups did not differ in urine output or fluid-carbohydrate supply during the first 96 hours. For medium-term morbidity, there were no differences in neonatal clinical outcomes in responders. However, significant differences were found in the incidence of patent ductus arteriosus, bronchopulmonary dysplasia, need for high-frequency ventilation, occurrence of necrotizing enterocolitis, and death between responders and nonresponders.

CONCLUSIONS

Low/moderate-dose epinephrine is as effective as low/moderate-dose dopamine for the treatment of hypotension in low birth weight infants, although it is associated with more transitory adverse effects.

Volume resuscitation: crystalloid versus colloid

Adequate circulating volume to maintain mean arterial blood pressure above a critical value is necessary to reverse bradycardia by positive-pressure ventilation during resuscitation after asphyxia. A variety of circumstances can lead to visible or occult blood loss in the perinatal period; however, distinguishing hypovolemic shock from asphyxial shock can be difficult in the delivery room. Small, randomized, controlled trials support the usefulness of isotonic crystalloid rather than albumin-containing solutions for acute volume expansion; ready availability, lower cost, and lesser risk of infectious complications favor the use of isotonic crystalloid as well. No trials have compared crystalloid and colloid for volume expansion in the setting of immediate resuscitation after birth. Further work is needed to refine the approach to infants in whom adequate positive-pressure ventilation fails and to better discriminate between shock on the basis of hypovolemia versus decreased myocardial function.

Prospective evaluation of postnatal steroid administration: a 1-year experience from the California Perinatal Quality Care Collaborative

OBJECTIVE

Postnatal steroids (PNSs) are used frequently to prevent or treat chronic lung disease (CLD) in the very low birth weight (VLBW) infant, and their use continues despite concerns regarding an increased incidence of longer-term neurodevelopmental abnormalities in such infants. More recently, there has been a suggestion that corticosteroids may be a useful alternative therapy for hypotension in VLBW infants, but there have been no prospective reports of such use for a current cohort of VLBW infants.

METHODS

The California Perinatal Quality Care Collaborative (CPQCC) requested members to supplement their routine Vermont Oxford Network data collection with additional information on any VLBW infant treated during their hospital course with PNS, for any indication. The indication, actual agent used, total initial daily dose, age at treatment, type of respiratory support, mean airway pressure, fraction of inspired oxygen, and duration of first dosing were recorded.

RESULTS

From April 2002 to March 2003 in California, 22 of the 62 CPQCC hospitals reported supplemental data, if applicable, from a cohort of 1401 VLBW infants (expanded data group [EDG]), representing 33.2% of the VLBW infants registered with the CPQCC during the 12-month period. PNSs for CLD were administered to 8.2% of all VLBW infants in 2003, 8.6% of infants in the 42 hospitals that did not submit supplemental data (routine data-set group, compared with 7.6% in EDG hospitals). Of the 1401 VLBW infants in the EDG, 19.3% received PNSs; 3.6% received PNSs for only CLD, 11.8% for only non-CLD indications, and 4.0% for both indications. At all birth weight categories, non-CLD use was significantly greater than CLD use. The most common non-CLD indication was hypotension, followed by extubation stridor, for which 36 (16.3%) infants were treated. For hypotension, medications used were hydrocortisone followed by dexamethasone. Infants treated with PNSs exclusively for hypotension had a significantly higher incidence of intraventricular hemorrhage, periventricular leukomalacia, and death when compared with infants treated only for CLD or those who did not receive PNSs.

CONCLUSIONS

The common early use of hydrocortisone for hypotension and the high morbidity and mortality in children receiving such treatment has not been recognized previously and prospective trials evaluating the short- and long-term risk/benefit of such treatment are urgently required.

Summary proceedings from the cardiology group on cardiovascular instability in preterm infants

The appropriate determination of adequate tissue perfusion and the best approach to treatment of perceived abnormalities in blood pressure in the neonate remain controversial. There is no consensus regarding the actual definition of hypotension in the neonate or how best to raise perceived low blood pressure. In addition, there is no direct and prospectively collected information available on the result of treatment of a "low" blood pressure on neonatal morbidity and mortality. It also has not been clearly demonstrated that bringing systemic blood pressure to a "normal" range improve outcomes. However, it is widely accepted by clinicians that early and aggressive treatment of hypotension leads to improved neurologic outcome and survival in the neonate. Commonly used therapeutic maneuvers to correct systemic hypotension in the neonate include volume expansion, inotropic agents, and corticosteroids. Although there is a paucity of research on the cardiovascular response to these commonly used agents in neonates, among the commonly used inotropic drugs dopamine has been shown to be more effective than dobutamine in raising blood pressure in the neonate. The cardiology group focused on the use of inotropes, particularly dopamine and dobutamine, to treat very low birth weight infants with cardiac instability and neonatal postoperative cardiac patients. The cardiology group identified key issues that must be considered when designing studies of inotropic agents in preterm infants and proposed 2 clinical-trial designs: (1) a placebo-controlled trial with rescue for symptomatic infants; and (2) a targeted-blood pressure study. The first trial design would answer questions concerning efficacy of treatment with inotropic agents in this population. The second trial design would address concerns related to the lack of knowledge on normal blood pressure ranges in this population. The group identified specific design elements that would need to be addressed for the complicated trial design to study inotropic agents in neonates.

Cardiovascular Effects of Low-Dose Dexamethasone in Very Low Birth Weight Neonates with Refractory Hypotension

BACKGROUND

Administration of hydrocortisone and relatively high doses of dexamethasone increase blood pressure in volume- and pressor-resistant hypotensive preterm infants. However, little is known about the temporal relationship of dexamethasone administration and the improvement in blood pressure and the weaning of pressors/inotropes. Furthermore, there are no sufficient data available on whether a smaller dose of dexamethasone would also be effective in treating refractory hypotension.

OBJECTIVE

To study the cardiovascular responses to low-dose dexamethasone in very low birth weight neonates with volume- and pressor-resistant hypotension.

METHODS

Retrospective database review. Twenty-four preterm neonates (gestational age 26 (23-34) weeks; birth weight 801 (457-1,180) g; postnatal age 2 (1-24) days, medians (ranges)) who remained hypotensive despite volume administration and combined dopamine and dobutamine treatment at >or=30 microg/kg/min received dexamethasone 0.1 mg/kg followed by 0.05 mg/kg intravenously every 12 h for 5 additional doses if still on pressors >or=8 microg/kg/min.

RESULTS

Two hours after the first dose of dexamethasone the mean blood pressure increased from 30 +/- 5 to 34 +/- 6 mm Hg (p < 0.001) and remained elevated at 4, 6, 12, and 24 h after treatment was started (p < 0.001). Six hours after the initial dose of dexamethasone the pressor/inotrope requirement decreased from 34 +/- 9 to 24 +/- 13 microg/kg/min (p = 0.001) and continued to decrease at 12 and 24 h (p < 0.001). Urine output also increased significantly during the first 6 h after dexamethasone (p < 0.001).

CONCLUSIONS

Low-dose dexamethasone rapidly increases blood pressure and decreases pressor requirements in very low birth weight neonates with volume- and pressor-resistant hypotension.

Use of volume expansion during delivery room resuscitation in near-term and term infants

OBJECTIVE

To characterize use of volume infusion (VI) for infants who are > or =34 weeks' gestational age and receive intensive cardiopulmonary resuscitation (CPR; defined as >1 minute of positive-pressure ventilation and chest compressions, with or without the administration of medications) in the delivery room and are admitted to the NICU.

METHODS

A retrospective review of a resuscitation registry between January 1999 and June 2001 was conducted.

RESULTS

Of 37,972 infants, 23 received CPR, including 13 with VI. Ten of 13 received VI for persistent bradycardia despite CPR, and only 3 of 13 received VI for suspicion of hypovolemia with poor perfusion. More VI versus no VI infants had Apgar scores < or =2 at 5 and 10 minutes. VI versus no VI infants had lower cord arterial pH, had higher arterial partial pressure of carbon dioxide, had larger base deficit, required longer CPR, and required more epinephrine. On admission to the NICU, VI versus no VI infants had lower blood pressure and larger base deficit over the first 2 hours but did not differ in arterial pH, arterial partial pressure of carbon dioxide, heart rate, mortality, or use of additional VI or buffer.

CONCLUSIONS

VI is rarely given for overt hypovolemia and more often for asphyxiated infants who are slow to respond to intensive CPR. Persistent postnatal hypotension in VI infants suggests that other factors, eg, myocardial dysfunction, may be important contributors to lack of response to CPR.

A randomized-controlled trial of prophylactic hydrocortisone supplementation for the prevention of hypotension in extremely low birth weight infants

OBJECTIVE

Extremely low birth weight (ELBW) infants are at risk for hypotension. Abnormal adrenal function may play a role in the pathogenesis of hypotension, and therefore, the administration of hydrocortisone (HC) may be an effective treatment for hypotension in some infants. However, the efficacy of prophylactic HC to prevent the use of vasopressors for a defined hypotensive state has not been studied. We conducted a randomized-controlled trial to determine the potential role on adrenal insufficiency in early neonatal hypotension and to determine the effectiveness of prophylactic HC in reducing treatment of hypotension in ELBW infants.

STUDY DESIGN

Infants were assigned to receive either HC or placebo within the first 3 hours of life. Therapy was continued for 5 days. The presence of hypotension was based on an operational definition and treatment with vasopressors (VP) was standardized based on an a priori protocol.

RESULTS

A total of 34 patients were enrolled. Baseline characteristics were similar between groups. Of the HC group 25% received VP at 24 hours of age compared to 44% of the placebo group. On day of life 2, only 7% of the HC group received VP compared to 39% of the placebo group (p<0.05).

CONCLUSION

Prophylactic treatment with HC reduces the incidence of hypotension, defined by treatment with VP, among ELBW infants during the first 2 days of life. However, the mounting evidence that prophylactic administration of glucocorticoids in the first days of life is harmful to ELBW infants makes HC prophylaxis unwise until the efficacy of treatment relative to safety can be clearly established.

Clinical detection of low upper body blood flow in very premature infants using blood pressure, capillary refill time, and central-peripheral temperature difference

OBJECTIVE

To determine the accuracy of blood pressure (BP), capillary refill time (CRT), and central-peripheral temperature difference (CPTd) for detecting low upper body blood flow in the first day after birth.

METHODS

A prospective, two centre cohort study of 128 infants born at < 30 weeks gestation. Invasive BP (n = 108), CRT (n = 128), and CPTd (n = 46) were performed immediately before echocardiographic measurement of superior vena cava (SVC) flow at three, 5-10, and 24 hours after birth.

RESULTS

Forty four (34%) infants had low SVC flow (< 41 ml/kg/min) in the first day, 13/122 (11%) at three hours, 39/126 (31%) at 5-10 hours, and 4/119 (3%) at 24 hours. CPTd did not detect infants with low flows. Combining all observations in the first 24 hours, CRT > or = 3 seconds had 55% sensitivity and 81% specificity, mean BP < 30 mm Hg had 59% sensitivity and 77% specificity, and systolic BP < 40 mm Hg had 76% sensitivity and 68% specificity for detecting low SVC flow. Combining a mean BP < 30 mm Hg and/or central CRT > or = 3 seconds increases the sensitivity to 78%.

CONCLUSIONS

Low upper body blood flow is common in the first day after birth and strongly associated with peri/intraventricular haemorrhage. BP and CRT are imperfect bedside tests for detecting low blood flow in the first day after birth.

Treatment of hypotension in newborns

Systemic hypotension is a common complication of preterm birth affecting approximately one-third of very low-birthweight infants. There is considerable variation between neonatal units in the reported prevalence of hypotension, the threshold for therapeutic intervention and the nature of any cardiovascular support offered. Systemic hypotension is associated with adverse long-term neurodevelopmental outcome. The majority of preterm infants with hypotension have a normal or high left ventricular output, with low systemic vascular resistance often associated with a haemodynamically significant ductal shunt. Historically, volume expansion, dopamine and dobutamine have been the agents most commonly used to treat hypotension. Some hypotensive preterm infants have low cortisol levels, and corticosteroids are being used increasingly to prevent or treat hypotension in these babies.

Hypotension in the very low birthweight infant: the old, the new, and the uncertain

Hypotension occurs in up to 20% of very low birthweight infants, usually in the first 48 hours after birth. Its importance lies in its possible causal link with brain injury. Its management is controversial.

Volume expansion during neonatal intensive care: do we know what we are doing?

Although volume expansion is liberally used in newborn intensive care, we know little about its effects on hemodynamics or outcomes. Given appropriately to a truly hypovolemic baby, it can be life-saving, but the clinical diagnosis of hypovolemia is probably very inaccurate. We know that volume expansion has less effect on blood pressure than dopamine, and although it seems to produce immediate increases in systemic blood flow, we do not know for how long these increases are sustained. There is evidence to show that the routine use of volume expansion in preterm babies has no effect on outcome, and there is little evidence to support its routine use during resuscitation or the treatment of metabolic acidosis. Whether crystalloids or colloids are preferable is also unclear in newborns. In situations of concern related to circulatory compromise, if possible, define the hemodynamics echocardiographically. Otherwise, if in doubt, some volume should be given, although it is probably unwise to keep expanding the volume if this is not improving physiologic (blood pressure and heart rate) or echocardiographic systemic blood flow parameters.

Excessive volume expansion and neonatal death in preterm infants born at 27-28 weeks gestation

Volume expansion is used commonly in preterm infants to treat presumed hypovolaemia. However, the amount that should be given is uncertain. We present data that were obtained from anonymised regional case notes of Project 27/28, a national case-controlled study run by the Confidential Enquiry into Stillbirths and Deaths in Infancy. Various clinical parameters were analysed, including the volume expansion administered during the first 48 h of life. All deaths in the first year of the study in the West Midlands (cases, n = 22) and matched regional controls (survivors, n = 29) were included. The primary outcome was death within 28 days. Sixteen of the 22 deaths were considered 'not inevitable' on the basis of the neonates' condition at birth. These newborns received on average more than twice the volume expansion compared with controls in the first 48 h of life (38.2 vs. 18.2 mL/kg, P = 0.007). There were no significant differences between the groups in lowest blood pressure or base deficit within the first 12 h of life. Newborns who received >or= 30 mL/kg volume expansion in the first 48 h of life were more likely to die than those who received < 30 mL/kg (OR 4.5 [95% CI 1.2, 17.2]). Our data suggest that administration of >or= 30 mL/kg volume expansion is associated with increased mortality in neonates of 27-28 weeks' gestation. Unless there is clear evidence of hypovolaemia, clinicians should exercise caution when prescribing volume expansion.

Randomized trial of dobutamine versus dopamine in preterm infants with low systemic blood flow

OBJECTIVE

Our purpose was to determine if dobutamine or dopamine results in greater improvements in systemic blood flow in very preterm infants with low flow during the first 24 hours of life.

STUDY DESIGN

A 2-center, randomized, double-blind study. Infants (n = 42) with low superior vena cava (SVC) flow (<41 mL/kg/min) in the first 12 hours were randomly assigned to receive 10 mL/kg normal saline solution, followed by 10 microg/kg/minute of dobutamine or dopamine. If low flow persisted or recurred, the inotrope was increased to 20 microg/kg/minute, with crossover to the other inotrope if treatment failed to maintain flow.

RESULTS

Volume produced a more significant increase in SVC flow than dopamine (+43%). At the highest dose, dobutamine resulted in a significantly greater increase in SVC flow than dopamine (mean, +9.9 vs -3.2 mL/kg/min, P =.02). Dopamine resulted in a significantly greater increase in blood pressure. Infants receiving dobutamine only at 24 hours had a greater right ventricular output than infants receiving dopamine (mean, 295 vs 167 mL/kg/min, P <.001). Forty percent failed to increase or maintain SVC flow in response to either inotrope. No significant differences in mortality or morbidity were found.

CONCLUSIONS

Dobutamine produced a greater increase in blood flow than dopamine.

Blood pressure in the very low birth weight neonate

Few aspects of management of very low birth weight (VLBW; <1500 g) neonates have generated as much controversy as the assessment of blood pressure (BP) and need for treatment of perceived abnormalities of this physiologic variable. The approach to this problem may differ greatly among various institutions and even among clinicians within a given center. The purpose of this manuscript is to review available information regarding physiologic determinants and measurement of BP in VLBW neonates, normative data for BP, clinical factors that may affect BP in these at-risk neonates and studies in which presumed abnormalities of BP resulted in adverse clinical outcomes. Options for treatment of low BP in VLBW neonates also will be discussed.

Controversies in the diagnosis and management of hypotension in the newborn infant

Although close to half of the newborns admitted to neonatal intensive care units receive treatment for "hypotension," the normal physiologic blood pressure range ensuring appropriate organ perfusion in the neonate is unknown. Thus, the decision to treat hypotension in the newborn is based on statistically defined gestational and postnatal age-dependent normative blood pressure values and physicians' beliefs rather than on data bearing physiologic reference. Dopamine is the most widely used sympathomimetic amine in the treatment of neonatal hypotension, and it is more effective than dobutamine in raising blood pressure. Volume administration is less effective in the immediate postnatal period, and its extensive use is associated with significant untoward effects, especially in preterm infants. During the course of their disease, some of the sickest hypotensive newborns become unresponsive to volume and pressor administration. This phenomenon is caused by the desensitization of the cardiovascular system to catecholamines by the critical illness and relative or absolute adrenal insufficiency. The findings that steroids rapidly up-regulate cardiovascular adrenergic receptor expression and serve as hormone substitution in cases of adrenal insufficiency explain their effectiveness in stabilizing the cardiovascular status and decreasing the requirement for pressor support in the critically ill newborn with volume-and pressor-resistant hypotension. Finally, despite recent advances in our understanding of the pathophysiology and management of neonatal hypotension, there are few data on the impact of the treatment on organ blood flow and tissue perfusion and on neonatal morbidity and mortality.

Circulatory support of the sick preterm infant

In the majority of preterm infants, especially during the immediate postnatal period, hypotension is primarily caused by abnormal peripheral vasoregulation and/or myocardial dysfunction and not by absolute hypovolemia. Therefore, aggressive volume resuscitation is not warranted and is potentially harmful. Volume support should be limited to 10-20 ml/kg of isotonic saline administration and, if sustained normalization of the blood pressure cannot be achieved, early initiation of cardiovascular pharmacological support is recommended. However, in preterm infants who present with an identifiable volume loss, the kind of fluid lost should first be replaced. Due to its beneficial cardiovascular and renal actions, dopamine is the drug of choice in the treatment of neonatal hypotension. Dobutamine may be added if myocardial dysfunction persists or develops during dopamine treatment. In some critically ill preterm infants, escalation of dopamine therapy or addition of epinephrine is necessary yet not always effective indicating the development of pressor resistant hypotension. Downregulation of cardiovascular adrenergic receptors and some degree of adrenal insufficiency may explain this phenomenon. In these patients, a brief course of steroid treatment may be successful in stabilizing the cardiovascular status and decreasing the requirement for pressor/inotrope support. However, well-designed randomized and controlled clinical trials are needed in the future to determine the effectiveness and potential short- and long-term side effects of steroid administration in preterm infants with pressor-resistant hypotension. In summary, management of the critically ill hypotensive preterm infant remains challenging and requires a better understanding of the pathophysiology of neonatal shock and improvements in our ability to evaluate cardiac output, organ blood flow, and tissue perfusion at the bedside.

Early volume expansion versus inotrope for prevention of morbidity and mortality in very preterm infants

BACKGROUND

Reduced perfusion of organs such as the brain, heart, kidneys and the gastrointestinal tract may lead to acute dysfunction and be associated with permanent injury. Various strategies have been used to provide cardiovascular support to preterm infants including inotropes, corticosteroids and volume expansion.

OBJECTIVES

In very preterm infants, to determine the effect of early volume expansion compared to inotrope in reducing morbidity and mortality. Subgroup analysis was planned according to method of diagnosis of poor perfusion, postnatal age of treatment and type of volume expansion and inotrope used.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used.

SELECTION CRITERIA

All randomised trials that compared volume expansion to an inotrope in preterm infants in the first days of life were included.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by each author and analysed using the standard methods of the Cochrane Collaboration and its Neonatal Review Group using relative risk (RR), risk difference (RD) and weighted mean difference (WMD).

MAIN RESULTS

Two small studies comparing volume expansion, using albumin, with dopamine were included. Both studies were adequately randomised, unblinded studies of albumin versus dopamine with no losses to follow up and analysed by intention to treat. Data for clinical outcomes were available from one study in hypotensive preterm infants in the first day of life. In this study, albumin had a higher failure rate for correcting hypotension (RR 5.2, 95% CI 1.3, 20.6). As 49% of these infants had already been given volume, the question of which treatment should be given first was not answered. A second study compared albumin with dopamine in preterm infants with a normal mean blood pressure at a mean age of 32 hours. Dopamine produced a significant increase in mean blood pressure when compared to infants who received albumin or no treatment, although the difference between the dopamine and albumin groups did not reach significance. Albumin and dopamine produced similar increases in left ventricular output but no significant change in cerebral blood flow. No difference was found in mortality (RR 1.5, 95% CI 0.5, 4.0) or morbidity including any P/IVH, chronic lung disease or retinopathy. There was a higher rate of grade 2-4 P/IVH of borderline statistical significance in infants who received albumin in one study (RR 1.47; 95% CI 0.96 to 2.25: RD 0.27, 95% CI 0.00 to 0.54). No data were available for neurodevelopmental outcomes.

REVIEWER'S CONCLUSIONS

Dopamine was more successful than albumin at correcting low blood pressure in hypotensive preterm infants, many of whom had already received volume. Neither intervention has been shown to be superior at improving blood flow, or in improving mortality and morbidity in preterm infants. The trials do not allow any firm conclusions to be made as to whether or when volume or dopamine should be used in preterm infants.

The haemodynamic effects of dopamine and volume expansion in sick preterm infants

AIM

To determine the haemodynamic effects of dopamine and volume expansion in preterm neonates. Effect parameters were mean arterial blood pressure (MABP), left ventricular output (LVO) and global cerebral blood flow (CBF).

METHODS

In a randomised, clinical control trial 36 preterm neonates were randomised to receive either dopamine 5 microg/kg per min, volume expansion with albumin 20% 15 ml/kg or no treatment. Parameters were measured before and 2 h after initiation of treatment.

RESULTS

Dopamine was effective in increasing MABP; both treatments increased LVO, whereas no significant difference between the treatment groups and the control group could be demonstrated with regard to CBF.

CONCLUSION

No effect on global cerebral blood flow could be demonstrated in this study, despite significant effects on systemic circulatory parameters. However, the variance on the measurement of cerebral blood flow indicates that a small but clinically significant effect may have been overlooked.

Dopamine versus dobutamine for hypotensive preterm infants

BACKGROUND

Inotropes are widely used in preterm infants to treat systemic hypotension. The most commonly used drugs are dopamine and dobutamine. These agents have different modes of action which may result in different haemodynamic effects.

OBJECTIVES

To compare the effectiveness and safety of dopamine and dobutamine in the treatment of systemic hypotension in preterm infants.

SEARCH STRATEGY

The standard search method of the Cochrane Neonatal Review Group was used. Searches of electronic and other databases were performed. Previous reviews were searched for references to relevant trials and leading authors in the field were contacted for information about other published and unpublished studies.

SELECTION CRITERIA

Randomised controlled trials where short and/or long term effects of treatment with dopamine and dobutamine for the treatment of systemic arterial hypotension were compared were selected for this review. Trials studying newborn infants born before 37 completed weeks gestation and less than 28 days of age were eligible for inclusion. Systemic arterial hypotension was not defined specifically, but accepted as defined in individual studies. Studies were not limited by birthweight, lower gestational age threshold or by route or duration of administration of inotropic agents. Study quality and eligibility were assessed independently by each reviewer.

DATA COLLECTION AND ANALYSIS

The standard method of the Cochrane Collaboration described in the Cochrane Collaboration Handbook was used to perform this systematic review. Data extraction was performed independently by each reviewer, with differences being resolved by discussion. The following outcomes were determined: mortality in the neonatal period, long term neurodevelopmental outcome, radiological evidence of severe neurological injury, short term haemodynamic changes and incidence of adverse effects. The effect of interventions is expressed either as Relative Risk (RR), Risk Difference (RD) or as Weighted Mean Difference (WMD) with their 95% Confidence Interval (CI).

MAIN RESULTS

Four trials met the pre-defined criteria for inclusion in this review. There was no evidence of a significant difference between dopamine and dobutamine in terms of neonatal mortality (RD 0.02 95% CI -0.12 to 0.16), incidence of periventricular leukomalacia (RD -0.08, 95% CI -0.19 to 0.04), or severe periventricular haemorrhage (RD -0.02, 95% CI -0.13 to 0.09). Dopamine was more successful than dobutamine in treating systemic hypotension, with fewer infants having treatment failure (RD -0.29, 95% CI -0.42 to -0.17; NNT = 3.5, 95% CI 2.4 to 5.9). There was no evidence of a significant difference in change in left ventricular output when dopamine was compared with dobutamine (WMD -83 ml/kg/min, 95% CI -174 to 8 ml/kg/min). There was no evidence of a significant difference between the two agents with respect to the incidence of tachycardia (RD -0.06, 95% CI -0.25 to 0.14). None of the studies reported the incidence of adverse long term neurodevelopmental outcome.

REVIEWER'S CONCLUSIONS

Dopamine is more effective than dobutamine in the short term treatment of systemic hypotension in preterm infants. There was no evidence of an effect on the incidence of adverse neuroradiological sequelae (severe periventricular haemorrhage and/or periventricular leucomalacia), or on the incidence of tachycardia. However, in the absence of data confirming long term benefit and safety of dopamine compared to dobutamine, no firm recommendations can be made regarding the choice of drug to treat hypotension.