Randomised trial of fluid restriction in ventilated very low birthweight infants

A Systematic Review: Is Early Fluid Restriction in Preterm Neonates Going to Prevent Bronchopulmonary Dysplasia?

Preterm birth causes constant challenges, with bronchopulmonary dysplasia (BPD) being a major concern. Immediately after birth, it takes time to establish feeding between the mother and the premature baby. During this time, the telological shifting of fluid from extracellular space to intracellular space will help the baby; this transition should be smooth. Both normal physiologic changes and pathophysiologic events are capable of disrupting this delicate fluid shifting that occurs in very low-birth-weight infants during the first week of life. The immaturity of the renal system and evaporative losses complicate this process. This lack of fluid displacement can be associated with an increased amount of water in the lungs and reduced lung compliance. This can lead to the need for more ventilatory support and a higher oxygen requirement, which, in turn, leads to lung damage. The fluid restriction is also associated with complications such as severe dehydration, intracranial hemorrhage, and bilirubin toxicity. However, the administration of large amounts of fluid and salt is associated with an increased incidence of patent ductus arteriosus, BPD, necrotizing enterocolitis, and intraventricular hemorrhage. There were studies conducted in both the pre-surfactant and surfactant eras that were inconclusive regarding fluid restriction in BPD. We only included very recent studies. This systematic review attempts to summarize the current evidence, focusing on the efficacy and safety of early fluid management in preterm infants. This reduces the risk of BPD and improves outcomes for premature infants. As we know, intact survival is very important. Our review supported the early fluid restriction.

The prevention and management strategies for neonatal chronic lung disease

INTRODUCTION

Survival from even very premature birth is improving, but long-term respiratory morbidity following neonatal chronic lung disease (bronchopulmonary dysplasia (BPD)) has not reduced. Affected infants may require supplementary oxygen at home, because they have more hospital admissions particularly due to viral infections and frequent, troublesome respiratory symptoms requiring treatment. Furthermore, adolescents and adults who had BPD have poorer lung function and exercise capacity.

AREAS COVERED

Antenatal and postnatal preventative strategies and management of infants with BPD. A literature review was undertaken using PubMed and Web of Science.

EXPERT OPINION

There are effective preventative strategies which include caffeine, postnatal corticosteroids, vitamin A, and volume guarantee ventilation. Side-effects, however, have appropriately caused clinicians to reduce use of systemically administered corticosteroids to infants only at risk of severe BPD. Promising preventative strategies which need further research are surfactant with budesonide, less invasive surfactant administration (LISA), neurally adjusted ventilatory assist (NAVA) and stem cells. The management of infants with established BPD is under-researched and should include identifying the optimum form of respiratory support on the neonatal unit and at home and which infants will most benefit in the long term from pulmonary vasodilators, diuretics, and bronchodilators.

Use of Albumin in the NICU: An Evidence-based Review

Albumin is the most abundant protein in human blood with distinctive functions throughout the human body. Low albumin levels are a predictor of mortality as well as disease outcome in children and adults. However, the clinical significance of hypoalbuminemia and the role of albumin infusions in NICUs remain unclear and controversial.

Association between fluid overload and mortality in newborns: a systematic review and meta-analysis

Fluid overload (FO) is associated with higher rates of mortality and morbidity in pediatric and adult populations. The aim of this systematic review and meta-analysis was to investigate the association between FO and mortality in critically ill neonates. Systematic search of Ovid MEDLINE, EMBASE, Cochrane Library, trial registries, and gray literature from inception to January 2021. We included all studies that examined neonates admitted to neonatal intensive care units and described FO and outcomes of interest. We identified 17 observational studies with a total of 4772 critically ill neonates who met the inclusion criteria. FO was associated with higher mortality (OR, 4.95 [95% CI, 2.26-10.87]), and survivors had a lower percentage of FO compared with nonsurvivors (WMD, - 4.33 [95% CI, - 8.34 to - 0.32]). Neonates who did not develop acute kidney injury (AKI) had lower FO compared with AKI patients (WMD, - 2.29 [95% CI, - 4.47 to - 0.10]). Neonates who did not require mechanical ventilation on postnatal day 7 had lower fluid balance (WMD, - 1.54 [95% CI, - 2.21 to - 0.88]). FO is associated with higher mortality, AKI, and need for mechanical ventilation in critically ill neonates in the intensive care unit. Strict control of fluid balance to prevent FO is essential. A higher resolution version of the Graphical abstract is available as Supplementary information.

The Impact of Hypernatremia in Preterm Infants on Neurodevelopmental Outcome at 18 Months of Corrected Age

OBJECTIVE

The study objective was to assess the correlation between hypernatremia during the first week of life and neurodevelopmental outcomes at 18 months of corrected age in premature infants.

STUDY DESIGN

A retrospective observational study of preterm infants born at less than 32 weeks of gestation who had a neurodevelopmental assessment with the Bayley scales of infant and toddler development III at 18 ± 6 months of corrected age. Serum sodium levels from birth through 7 days of life were collected. The study cohort was divided into two groups: infants with a peak serum sodium of >145 mmol/L (hypernatremia group) and infants with a peak serum sodium level of <145 mmol/L (no hypernatremia group). Prenatal, intrapartum, and postnatal hospital course and neurodevelopmental data at 18 ± 6 months were collected. Logistic regression analysis was used to assess the correlation between neonatal hypernatremia and neurodevelopment with adjustment for selected population characteristics.

RESULTS

Eighty-eight preterm infants with complete neurodevelopmental outcome data at 18 ± 6 months of corrected gestational age were included in the study. Thirty-five neonates were in the hypernatremia group and 53 were in the no hypernatremia group. Maternal and neonatal characteristics were similar between the two groups except that the hypernatremia group had a significantly lower average birth weight and gestational age. Comparison of the mean neurodevelopmental scores between the two groups showed that patients in the hypernatremia group as compared with those in the no hypernatremia group had significantly lower neurodevelopmental scaled scores in the fine motor domain (p = 0.01). This difference remained significant (p = 0.03, odds ratio [OR] = 0.8, 95% confidence interval [CI]: 0.6-0.97) when adjusted for birth weight and gestational age.

CONCLUSION

Preterm infants born at less than 32 weeks of gestation with hypernatremia in the first week of life have lower fine motor scores at 18 months of corrected age.

KEY POINTS

· Hypernatremia is a common electrolyte disturbance in preterm neonates.. · Hypernatremia may be associated with long-term neurodevelopmental outcomes in preterm infants.. · Hypernatremia is a potentially modifiable risk factor..

Know the Code: Medications for Resuscitation in Neonates

Resuscitations in the delivery room or the nursery cause significant stress for caregivers. Diligent preparation will improve the efficacy and safety of life-saving interventions and increase staff comfort. When establishment of an airway and delivery of positive pressure ventilation and chest compressions fail to result in return of spontaneous circulation, pharmacotherapeutic interventions should be considered. Epinephrine is first-line pharmacotherapy for severe bradycardia or cardiac arrest, increasing coronary arterial pressure and blood flow during chest compressions. Despite limited data regarding dosing and efficacy, the first dose of epinephrine may be delivered through the endotracheal tube during attainment of venous access (preferably a low-lying umbilical venous catheter in the delivery room). Intravenous dosing is preferred, and any facility caring for newborns must ensure optimized logistics including readily available dosing guidance and optimal flush volumes. After provision of epinephrine, additional medications may be considered, especially for resuscitations occurring outside of the immediate perinatal period, including normal saline, glucose, adenosine, atropine, and calcium. Clinicians must understand the indications, dosing, and monitoring parameters for these medications and ensure rapid availability for resuscitation. Every second truly counts in a neonatal resuscitation, and optimal understanding and preparation will ensure delivery of pharmacotherapy to optimize both patient outcomes and staff comfort.

A physiological approach to fluid and electrolyte management of the preterm infant: Review

Despite the fact that hundreds of thousands of preterm infants receive parenteral fluids each year, study of optimal fluid and electrolyte management in this population is limited. Compared to older children and adults, preterm infants have an impaired capacity to regulate water and electrolyte balance. Appropriate fluid and electrolyte management is critical for optimal care of low birth weight or sick infants, as fluid overload and electrolyte abnormalities pose significant morbidity. This review highlights basic physiological principles which need to be applied when prescribing parenteral fluids and builds upon published literature to outline a rational approach to initial fluid and electrolyte management of the preterm infant.

In preterm infants, does fluid restriction, as opposed to liberal fluid prescription, reduce the risk of important morbidities and mortality?

AIM

To answer the clinical question: 'In preterm infants, does fluid restriction, as opposed to liberal fluid prescription, reduce the risk of important morbidities (namely, intraventricular haemorrhage, necrotising enterocolitis, bronchopulmonary dysplasia and patent ductus arteriosus) and mortality?'

METHODS

Literature searches were conducted of Medline, Embase and Cochrane Library. Results were limited to human clinical trials on infants and those published in English. The reference lists of relevant articles were screened for further articles. Studies that examined measures which inform diagnostic criteria of morbidities of interest (such as echocardiographic changes) but did not go further to confirm or exclude presence of said morbidities in study populations were excluded.

RESULTS

A total of 110 articles were found and screened by title and abstract. The final analysis included five randomised controlled trials and five case control studies. Among the randomised controlled trials, there is some suggestion (though not unanimous) that liberal fluid regimens are associated with an increased risk of patent ductus arteriosus, necrotising enterocolitis and mortality. Case control studies focused on patent ductus arteriosus and bronchopulmonary dysplasia or chronic lung disease, with all but one study suggesting an increased risk of these complications with liberal fluid regimens.

CONCLUSION

Further investigation is needed to clarify the optimal fluid regimen for preterm infants to ensure adequate hydration and nutrition without contributing to serious complications.

Prevention of Bronchopulmonary Dysplasia: A Summary of Evidence-Based Strategies

Bronchopulmonary dysplasia (BPD) is the most common chronic complication associated with extremely preterm birth. Although BPD is now an uncommon condition in infants born with birthweights higher than 1,500 g, among infants born at or near the current limits of viability, BPD rates have not improved over the past 2 to 3 decades and may be increasing. No single therapeutic intervention is effective at preventing BPD. As such, clinicians must use multiple evidence-based strategies to help reduce BPD rates. This review examines current evidence-based approaches to BPD prevention, primarily focusing on data obtained from randomized controlled trials.

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.

Do early postnatal body weight changes contribute to neonatal morbidities in the extremely low birth weight infants

BACKGROUND

The implications of early postnatal body weight changes (Δbw) in the morbidities related to body fluid metabolism in sick preterm infants in not well investigated. The extremely low birth weight infants (ELBW, birth weight <1000 g) have the highest incidence of such morbidities among all neonates.

AIM

To determine the relationships between Δbw and neonatal morbidities associated with body fluid metabolism in the ELBW infants.

METHODS

In an observational study, the associations between daily weight changes from birth weight (DΔ bw) and oxygen dependence on postnatal day 28 (BPD28), patent ductus arteriosus (PDA), intraventricular-periventricular hemorrhage (IVH), antenatal steroid (ANS) and gestational age (GA) were evaluated. Maximum weight loss (MΔ bw) was correlated with GA, BPD28 and BPD36 (oxygen dependence on postmenstrual 36 weeks). Pearson's correlation co-efficient and multivariate logistic regressions were performed for analysis.

RESULTS

DΔ bw correlated inversely with GA on days 1-8 of life (p <  0.01 for all, 0.06 for DOL 2). DΔ bw was associated with a lower risk of BPD28 on days 6 (OR 0.87, 95% CI 0.76-1), 10 (OR 0.86, 95% CI 0.76-0.98) and 11 (OR 0.87, 95% CI 0.77-0.99); with PDA on days 8-11 (OR ranging between 0.89 to 0.92 for the 4 days, 95% CI 0.83 to 0.99) and with IVH on day 5 (OR 0.93, 95% CI 0.86-1) after controlling for GA. DΔ bw was not identified as risk factor for the tested morbidities. ANS decreased DΔ bw on days 4 (OR 0.88, 95% CI 0.78-1) and 10 (OR 0.9, 95% CI 0.84-1). MΔbw correlated directly with BPD28 (r = 0.3, p = 0.004), which declined after controlling for GA (r = 0.2, p = 0.2).

CONCLUSIONS

DΔ bw is protective for PDA, BPD28 and IVH, independent of gestational age, whereas, the effects of MΔ bw on BPD are governed by maturation in ELBW infants. ANS decreases DΔbw, which correlates inversely with GA during the first week of life.

Management during the first 72 h of age of the periviable infant: an evidence-based review

After NICU admission the extremely immature newborn (EIN) requires evaluation and support of each organ system, and the integration of all those supports in a comprehensive plan of care. In this review, I attempt to analyze the evidence for treatment options after the initial transition, during the first 3 days of life, which have been shown to improve survival or short- or long-term morbidity. This review revealed several things: there is little available evidence from studies that have included significant numbers of EINs; interventions affecting different organ systems need to be co-ordinated as any intervention will have multiple effects; and future advances in treatment of this group of patients will require the installation of permanent research networks to have enough power to perform many studies needed to improve outcomes.

Fluid homeostasis in the neonate

The physiology of the neonate is ideally suited to the transition to extrauterine life followed by a period of rapid growth and development. Intravenous fluids and electrolytes should be prescribed with care in the neonate. Sodium and water requirements in the first few days of life are low and should be increased after the postnatal diuresis. Expansion of the extracellular fluid volume prior to the postnatal diuresis is associated with poor outcomes, particularly in preterm infants. Newborn infants are prone to hypoglycemia and require a source of intravenous glucose if enteral feeds are withheld. Anemia is common, and untreated is associated with poor outcomes. Liberal versus restrictive transfusion practices are controversial, but liberal transfusion practices (accompanied by measures to minimize donor exposure) may be associated with improved long-term outcomes. Intravenous crystalloids are as effective as albumin to treat hypotension, and semi-synthetic colloids cannot be recommended at this time. Inotropes should be used to treat hypotension unresponsive to intravenous fluid, ideally guided by assessment of perfusion rather than blood pressure alone. Noninvasive methods of assessing cardiac output have been validated in neonates. More studies are required to guide fluid management in neonates, particularly in those with sepsis or undergoing surgery. A balanced salt solution such as Hartmann's or Plasmalyte should be used to replace losses during surgery (and blood or coagulation factors as indicated). Excessive fluid administration during surgery should be avoided.

Restricted versus liberal water intake for preventing morbidity and mortality in preterm infants

BACKGROUND

Most premature infants are physiologically not sufficiently mature to orally ingest all of their required water and nutrients. Therefore, premature infants rely on their caregivers to regulate their volume of water intake. Thus, the caregiver must determine the amount of water to be given each day to such infants.

OBJECTIVES

To determine the effect of water intake on postnatal weight loss and the risks of dehydration, patent ductus arteriosus, necrotizing enterocolitis, bronchopulmonary dysplasia, intracranial hemorrhage, and death in premature infants.

SEARCH METHODS

Randomized clinical trials (RCTs) identified in previous versions of this review were re-examined and, in each case, retained. Additional trials were sought that compared the outcomes of interest in groups of premature infants who were given different levels of water intake according to an experimental protocol. Such trials were sought in a list of trials provided by the Cochrane Neonatal Review Group, with a PubMed search and in the authors' personal files.This search was updated in 2014.

SELECTION CRITERIA

Only RCTs of varying water intake in premature infants were included. The review was limited to trials that included infants whose water intake was provided mainly or entirely by intravascular infusion.

DATA COLLECTION AND ANALYSIS

The standard methods of The Cochrane Collaboration were used. Study selection and data abstraction were performed independently by each review author. The adverse event rates were calculated for the restricted and liberal water intake groups for each dichotomous outcome, and the relative risk and risk difference were computed. In addition, the maximal weight loss results were recorded and the weighted mean difference was computed.

MAIN RESULTS

The analysis of the five studies taken together indicated that restricted water intake significantly increased postnatal weight loss and significantly reduced the risks of patent ductus arteriosus and necrotizing enterocolitis. With restricted water intake, there were trends toward increased risk of dehydration and reduced risks of bronchopulmonary dysplasia, intracranial hemorrhage, and death but these trends were not statistically significant.

AUTHORS' CONCLUSIONS

Based on this analysis, the most prudent prescription for water intake to premature infants would seem to be careful restriction of water intake so that physiological needs are met without allowing significant dehydration. This practice could be expected to decrease the risks of patent ductus arteriosus and necrotizing enterocolitis without significantly increasing the risk of adverse consequences.

Learning to live with patency of the ductus arteriosus in preterm infants

Treatment of persistent patency of the ductus arteriosus in preterm infants remains heterogeneous and controversial. Routine early treatment to induce ductal closure is not beneficial, but the potential criteria for, timing of, methods for and benefits of later ductal closure have not been determined. Management strategies for infants awaiting spontaneous closure or meeting criteria for treatment may be based on pathophysiological considerations but require evaluation in clinical trials. Better diagnostic tools allowing the identification of infants who might benefit from ductal closure, supplemented by data from clinical trials confirming realization of that potential, are urgently needed.

Fluid, electrolytes, and nutrition: minutes matter

Historically, in very low-birth-weight infant care, nutritional support was delayed during the first postnatal days because of fear of toxicity and harm with immature metabolic systems and intestinal function. Recent evidence demonstrates that early nutritional support is not only safe but likely necessary to optimize infant growth and neurodevelopment. In fact, nutrition management is a critical factor in very low-birth-weight infant golden hour support. Contemporary studies in protein and lipid intravenous support and early feeds as minimal enteral nutrition exhibit safety and some efficacy. We will present analysis of this evidence and development of potential better practices on the basis of these data as well as a review of golden hour fluid and glucose management. In addition, we provide several outcomes following our adoption of potentially better golden hour nutrition practices.

Acute lung injury in preterm newborn infants: mechanisms and management

Respiratory morbidity and mortality remain common in preterm infants. The immature preterm lung is especially prone to injury. This process often starts in-utero due to maternal chorioamnionitis, priming the lung for further injury in response to post-natal ventilation, oxygen and nosocomial infection. Pulmonary inflammation has been strongly implicated in the pathway leading to lung injury in this population of infants. Several therapeutic approaches have been attempted to prevent acute lung injury or to limit its progress. The mechanisms of acute lung injury in preterm infants; their clinical correlates and available therapeutic approaches are reviewed here.

Quality improvement in respiratory care: decreasing bronchopulmonary dysplasia

Chronic lung disease (CLD) is one of the most common long-term complications in very preterm infants. Bronchopulmonary dysplasia (BPD) is the most common cause of CLD in infancy. Modern neonatal respiratory care has witnessed the emergence of a new BPD that exhibits decreased fibrosis and emphysema, but also decreased alveolar septation, and microvascular development. CLD encompasses the classic and the new BPD, and recognizes that lung injury can occur in term infants who need aggressive ventilatory support and who develop lung injury as a result, and that CLD is a multisystem disease. Controversy exists on whether quality improvement (QI) methods that implement multiple interventions will be effective in limiting pathology with multiple causes. Caution in generalization of QI findings is encouraged. QI methods toward improvement in CLD or any other outcome should be considered as a tool for implementing evidence and studying the effects of change in complex adaptive systems.

Albumin versus normal saline for dehydrated term infants with metabolic acidosis due to acute diarrhea

To compare the efficacy of albumin to normal saline (NS) for initial hydration therapy for dehydrated term infants with severe metabolic acidosis due to acute diarrhea.

STUDY DESIGN

We randomized 33 infants presenting with moderate-to-severe dehydration and metabolic acidosis (pH <7.25 or base excess (BE) <-15) into two groups, an albumin group (n=15) and a NS group (n=18). For initial hydration treatment, the albumin group received 5% albumin (10 ml kg(-1)), whereas the NS group received NS (10 ml kg(-1)).

RESULT

After 3 h of treatment, both groups improved. However, the magnitude of improvement in the pH, BE and HCO(3)(-) levels were not different in comparisons between these two groups. In addition, there were no differences either in the body weight and weight gain 4 days after treatment or in the length of hospital stay.

CONCLUSION

Albumin was not more effective than NS for initial hydration treatment of dehydrated term infants with metabolic acidosis due to acute diarrhea.

Randomized trial of sterile water by gavage drip in the fluid management of extremely low birth weight infants

OBJECTIVE

To determine whether extremely low birth weight infants who receive enteral sterile water have a reduction in treated patent ductus arteriosus or death by 28 days compared to infants with routine management.

STUDY DESIGN

A total of 214 infants were enrolled and randomized by 36 h of age to receive up to 50 ml kg(-1) per day of enteral sterile water (n=109) for 7 days or routine fluid management (n=104). Patent ductus arteriosus treatment was defined as either indomethacin treatment or surgical ligation.

RESULT

The proportion of infants with a treated patent ductus arteriosus or death at <28 days of age was 63% in the sterile water group vs 64% in the control group (relative risk 0.99, 95% confidence interval 0.81 to 1.22). There were no differences in the proportion of infants in the sterile water group vs control group with a treated patent ductus arteriosus (55 vs 48%), death (21 vs 28%), necrotizing enterocolitis or death (24 vs 32%), or bronchopulmonary dysplasia or death at <28 days (80 vs 77%). Daily mean glucose levels were significantly higher (P=0.04) in control infants than sterile water infants.

CONCLUSION

The use of sterile water did not decrease the incidence of patent ductus arteriosus or other adverse clinical outcomes. The role of enteral sterile water in the fluid management of extremely low birth weight infants remains uncertain.

Fluid regimens in the first week of life may increase risk of patent ductus arteriosus in extremely low birth weight infants

BACKGROUND

High fluid volumes may increase neonatal morbidity. However, evidence supporting fluid restriction is inconclusive and restricting fluids may restrict caloric intake.

OBJECTIVE

To determine if higher fluid intake was associated with increased risk of patent ductus arteriosus (PDA) or bronchopulmonary dysplasia (BPD) in extremely low birth weight (ELBW) infants.

STUDY DESIGN

A total of 204 ELBW (<or=32 weeks, <or=1250 g) infant survivors were grouped into low-, intermediate- and high-fluid groups. chi2 analyzed proportions of subjects with and without morbidities across groups. Logistic regression quantified increased risk of PDA or BPD associated with fluid intake while controlling for confounders. Analysis of variance compared differences in caloric intake across groups.

RESULT

After controlling for gestational age, severity of illness and weight change, fluid intake on day 2 (odds ratio (OR) 1.014; confidence interval (CI) 1.001 to 1.028) and day 3 (OR 1.022; CI 1.004 to 1.040) was associated with increased risk of PDA.

CONCLUSION

High fluid intake (>170 ml kg(-1) day(-1)) in the first days of life is associated with increased risk of PDA.

Restricted versus liberal water intake for preventing morbidity and mortality in preterm infants

BACKGROUND

Most premature infants are not sufficiently mature physiologically to ingest all of their required water and nutrients orally. Therefore, premature infants rely on their caregivers to regulate their volume of water intake. Thus, the caregiver must determine the amount of water to be given each day to such infants.

OBJECTIVES

The objective of this review is to examine the effects of water intake on postnatal weight loss and on the risks of dehydration, patent ductus arteriosus, necrotizing enterocolitis, bronchopulmonary dysplasia, intracranial hemorrhage, and death in premature infants.

SEARCH STRATEGY

Randomized clinical trials identified in previous versions of this review were re-examined and, in each case, retained. Additional trials were sought that compared the outcomes of interest in groups of premature infants who were given different levels of water intake according to experimental protocol. Such trials were sought in a list of trials provided by the Cochrane Neonatal Review Group, with a PubMed search, and in the authors' personal files.

SELECTION CRITERIA

Only randomized clinical trials of varying water intake in premature infants are included. The review was limited to trials that included infants whose water intake was provided mainly or entirely by intravascular infusion. Included studies reported at least one of the following outcomes: postnatal weight loss, dehydration, patent ductus arteriosus, necrotizing enterocolitis, bronchopulmonary dysplasia, intracranial hemorrhage, and death.

DATA COLLECTION AND ANALYSIS

Standard methods of the Cochrane Collaboration were used. The studies to be included were selected by two reviewers, each of whom also assessed the methodological quality of each trial. Data were independently extracted by the reviewers, who agreed on the key details. The data were then entered into tables using RevMan 4.3.1. The adverse event rates were calculated for the restricted and liberal water intake groups for each dichotomous outcome, and the relative risk and risk difference were computed. In addition, the maximal weight loss results were recorded, and the weighted mean difference was computed. The analyses - including calculation of relative risk, risk difference, and weighted mean difference - and tests of heterogeneity were accomplished using RevMan 4.3.1 software.

MAIN RESULTS

The analysis of the five studies taken together indicates that restricted water intake significantly increases postnatal weight loss and significantly reduces the risks of patent ductus arteriosus and necrotizing enterocolitis. With restricted water intake, there are trends toward increased risk of dehydration and reduced risks of bronchopulmonary dysplasia, intracranial hemorrhage, and death, but these trends are not statistically significant.

AUTHORS' CONCLUSIONS

Based on this analysis, the most prudent prescription for water intake to premature infants would seem to be careful restriction of water intake so that physiological needs are met without allowing significant dehydration. This practice could be expected to decrease the risks of patent ductus arteriosus and necrotizing enterocolitis without significantly increasing the risk of adverse consequences.

Association between early postnatal weight loss and death or BPD in small and appropriate for gestational age extremely low-birth-weight infants

OBJECTIVE

To examine the association between weight loss during the first 10 days of life and the incidence of death or bronchopulmonary dysplasia (BPD) in small for gestational age (SGA) and appropriate for gestational age (AGA) extremely low-birth-weight infants.

DESIGN/METHODS

This is a retrospective analysis of a cohort of ELBW (birth weight <1000 g) infants from the NICHD Neonatal Research Network's database. The cohort consisted of 9461 ELBW infants with gestational age of 24-29 weeks, admitted to Network's participating centers during calendar years 1994-2002 and surviving at least 72 h after birth. The cohort was divided into two groups, 1248 SGA (with birth weight below 10th percentile for gestational age) and 8213 AGA (with birth weight between 10th and 90th percentile) infants. We identified infants with or without weight loss during the first 10 days of life, which we termed as 'early postnatal weight loss' (EPWL). Univariate analyses were used to predict whether EPWL was related to the primary outcome, death or BPD, within each birth weight/gestation category (SGA or AGA). BPD and death were also analyzed separately in relation to EPWL. Logistic regression analysis was done to evaluate the risk of death or BPD in SGA and AGA groups, controlling for maternal and neonatal demographic and clinical factors found to be significant by univariate analysis.

RESULTS

SGA ELBW infants had a lower prevalence of EPWL as compared with AGA ELBW infants (81.2 vs 93.7%, respectively, P<0.001). In AGA infants, univariate analysis showed that death or BPD rate was lower in the group of infants with EPWL compared with infants without EPWL (53.4 vs 74.3%, respectively, P<0.001). The BPD (47.2 vs 64%, P<0.001) and death (13.8 vs 32.9%, P<0.001) rate were similarly lower in the EPWL group. The risk-adjusted odds ratios (ORs) showed that EPWL was associated with lower rate of death or BPD (OR 0.47, 95% CI: 0.37-0.60). In SGA infants, on univariate analysis, a similar association between EPWL and outcomes was seen as shown in AGA infants: death or BPD (55.9 vs 75.2%, P<0.001), BPD rate (48.3 vs 62.1%, P=0.002) and rate death (19 vs 40.8%, P<0.001) for those with or without EPWL, respectively. Multiple logistic regression showed that as in AGA ELBW infants, EPWL was associated with lower risk for death or BPD (OR 0.60, 95% CI: 0.41-0.89) among SGA infants.

CONCLUSIONS

SGA infants experienced less EPWL when compared with their AGA counterparts. EPWL was associated with a lower risk of death or BPD in both ELBW AGA and SGA infants. These data suggest that clinicians who consider the association between EPWL and risk of death or BPD should do so independent of gestation/birth weight status.

A scoring system to predict chronic oxygen dependency

INTRODUCTION

Chronic oxygen dependency (COD) is a common adverse outcome of very premature birth. It is, therefore, important to develop an accurate and simple predictive test to facilitate targeting of interventions to prevent COD. Our aim was to determine if a simple score based on respiratory support requirements predicted COD development.

METHODS

A retrospective study of 136 infants, median gestation age (GA) 28 weeks (range: 23-33 weeks) and a prospective study of 75 infants, median GA 30 weeks (range: 23-32 weeks), were performed. The score was calculated by multiplying the inspired oxygen concentration by the level of respiratory support (mechanical ventilation: 2.5; continuous positive airway pressure: 1.5; nasal cannula or head box oxygen or air: 1.0). Scores were calculated on data from days 2 and 7, and their predictive ability compared to that of the maximum inspired oxygen concentration at those ages and (retrospective study) the results of lung volume measurement.

RESULTS

Infants that were oxygen dependent at 28 days and 36 weeks post-menstrual age (PMA) had higher scores on days 2 (p<0.0001, p<0.0001, respectively) and 7 (p<0.0001, p<0.0001, respectively) than the non-oxygen dependent infants in both the retrospective and prospective cohorts. Construction of receiver operator characteristic curves demonstrated the score performed better than the inspired oxygen level and lung volume measurement results. A score on day 7 >0.323 had 95% specificity and 78% sensitivity in predicting COD at 28 days, and 80% specificity and 73% sensitivity in predicting COD at 36 weeks PMA.

CONCLUSION

Chronic oxygen dependency can be predicted using a simple scoring system.

Hypernatraemia in preterm infants born at less than 27 weeks gestation

AIMS

To study the incidence of hypernatraemia (plasma sodium >145 mmol/L), identify predisposing factors to and associated complications of hypernatraemia in preterm infants born less than 27 weeks gestation in the first 5 days of life.

METHODS

Preterm infants less than 27 week gestation over an 18-month period were studied by retrospective analysis of patient records. Data were collected on gestation, birthweight, sex, antenatal steroid use, phototherapy, incubator humidity, time of transfer to incubator, plasma sodium, urea and creatinine. Actual fluid and sodium intake was calculated for the first 5 days of life. Data were collected on chronic lung disease, patent ductus arteriosus, intraventricular haemorrhage, necrotising enterocolitis and death.

RESULTS

In this study 46 (69.7%) of 66 infants studied developed hypernatraemia (>145 mmol/L), occurring most frequently between 24 and 48 h of age. The median gestation of hypernatraemic babies was significantly lower. There was no significant difference in median birthweight, or factors associated with increased insensible water loss between the hypernatraemic and the non-hypernatraemic groups. Fluid intake was significantly higher on days 2, 3 and 4 in the hypernatraemic group. There was no difference in sodium intake between the two groups. More hypernatraemic babies compared with controls developed chronic lung disease, patent ductus arteriosus, significant intraventricular haemorrhage, necrotising enterocolitis and died, but was not significant.

CONCLUSION

Hypernatraemia occurs commonly in preterm infants less than 27 weeks gestation and was not associated with significant morbidity. The more immature infants developed hypernatraemia and all cases resolved after increasing fluid intake.

Bronchopulmonary dysplasia

Bronchopulmonary dysplasia is a chronic lung disease that affects premature babies and contributes to their morbidity and mortality. Improved survival of very immature infants has led to increased numbers of infants with this disorder. This increase puts a heavy burden on health resources since these infants need frequent re-admission to hospital in the first 2 years after birth and, even as adolescents, have lung-function abnormalities and persistent respiratory symptoms. Unlike the original description of the disease in 1967, premature infants can develop chronic oxygen dependency without severe, acute respiratory distress; this "new bronchopulmonary dysplasia" could be the result of impaired postnatal lung growth. Whether such infants subsequently have catch-up lung growth, especially if given corticosteroids postnatally, is unknown. No safe and effective preventive therapy has been identified, but promising new treatments directed either at reducing lung injury or improving lung growth are under study.

Association between fluid intake and weight loss during the first ten days of life and risk of bronchopulmonary dysplasia in extremely low birth weight infants

OBJECTIVE

To demonstrate the association between fluid intake and weight loss during the first 10 days of life and the risk of bronchopulmonary dysplasia (BPD) in extremely low birth weight (ELBW) infants.

STUDY DESIGN

A retrospective analysis of data from a cohort of ELBW infants enrolled in the Neonatal Research; 1,382 infants with birth weight between 401 and 1,000 g were randomized. The daily fluid intake and weight loss during the first 10 days of life were compared between the infants who survived without BPD and those who either died or developed BPD. Demographic and clinical neonatal variables were also compared. Multivariate logistic regression was used to analyze the effect of fluid intake and weight loss on death or BPD, controlling for demographic and clinical factors that are significantly associated with BPD by univariate analysis.

RESULTS

585 infants survived without BPD and 797 infants either died or developed BPD. Univariate analysis showed that the daily fluid intakes were higher (day 2-10) and weight loss less (day 6-9) in the group of infants who either died or developed BPD. In addition, lower birth weight, lower gestational age, male gender, lower 1 and 5-minute Apgar Scores, higher oxygen requirement at 24 hours of age, longer duration of assisted ventilation, use of postnatal steroids for BPD and presence of severe intraventricular hemorrhage, proven necrotizing enterocolitis, patent ductus arteriosus, and late onset sepsis, were associated with higher incidence of death or BPD. The adjusted risk of higher fluid intake and less weight loss during the first 10 days of life remained significantly related to death or BPD.

CONCLUSION

In this cohort of ELBW infants treated during the post surfactant era, higher fluid intake and less weight loss during the first 10 days of life were associated with an increased risk of BPD. The finding suggests that careful attention to fluid balance might be an important means to reduce the incidence of BPD.

Lung volumes in infants who had mild to moderate bronchopulmonary dysplasia

"New" bronchopulmonary dysplasia (BPD) has been suggested to be a maldevelopment sequence with reduced alveolarisation of the lungs; affected infants then would be predicted to have low lung volumes. The aim of this study was to test that hypothesis by comparing the lung volumes of infants who had had mild-moderate BPD with those without BPD of similar postmenstrual age. Lung volumes of 17 infants who had mild-moderate BPD (oxygen dependent beyond 28 days, but not past term) (BPD infants) were compared to those of 17 infants without BPD (non-BPD infants). All were born at less than 33 weeks of gestation and studied at postmenstrual ages of 33 to 39 weeks. Lung volume was assessed by measurement of functional residual capacity (FRC). The BPD infants had lower lung volumes (median 19.1 ml/kg) than the non-BPD infants (median 26.5 ml/kg) (p = 0.0001). The BPD compared to the non-BPD infants were of greater postnatal age (p = 0.0003), born at a lower gestational age (p = 0.0001) and of lighter birthweight (p = 0.0001). Regression analysis, however, demonstrated that lung volume was significantly related to BPD status (p = 0.005), independently of postnatal age, birthweight and gestational age. It is concluded that the lower lung volumes of the infants who had had mild-moderate BPD support the hypothesis that new BPD is associated with poor alveolarisation.

The albumin controversy

There are relatively few studies of albumin use in neonates and children, with most showing no consistent benefit compared with the use of crystalloid solutions. Certainly, albumin treatment is not indicated for treatment of hypoalbuminemia alone. Studies also show that albumin is not indicated in neonates for the initial treatment of hypotension, respiratory distress, or partial exchange transfusions. In adults, albumin is not considered to be the initial therapy for hypovolemia, burn injury, or nutritional supplementation. Based on the evidence, albumin should be used rarely in the neonatal ICU. Albumin may be indicated in the treatment of hypovolemia only after crystalloid infusion has failed. In patients with acute hemorrhagic shock, albumin may be used with crystalloids when blood products are not available immediately. Inpatients with acute or continuing losses of albumin and normal capillary permeability and lymphatic function, such as during persistent thoracostomy tube or surgical site drainage, albumin supplementation will prevent the development of hypoalbuminemia, and possibly edema formation. This has not been studied systematically, however. In patients with hypoalbuminemia and increased capillary permeability, albumin supplementation often leads to greater albumin leakage across the capillary membrane, contributing to edema formation without improvement in outcome. As the disease process improves and capillary permeability normalizes, albumin supplementation may accelerate recovery, but long-term benefits of albumin treatment usually cannot be demonstrated. These patients will recover whether or not albumin is administered.

A simple automatized audit system for following and managing practices of platelet and plasma transfusions in a neonatal intensive care unit

During neonatal intensive care, blood components are often used in clinical situations where both their efficacy and safety lack solid justification. A practical system to continuously analyse actual transfusion practices is a prerequisite for improvements of quality in transfusion therapy. We hypothesized that such a system would reveal inappropriate variations in clinical decision making and offer a means for staff education and quality improvement and assurance. The study consisted of three 120-152-day periods (P I, P II and P III) between January 2000 and October 2001 and involved 543 new patient admissions (141 patients with birth weight < 1501 g) and 6227 days of patient care at a single tertiary level NICU. P I was a control with no intervention, P II was after technically introducing the computer system and, the last period, P III was after presenting and discussing the results of P I and P II at a staff meeting. Upon an order of platelet or fresh frozen plasma (FFP) unit from the blood bank, a computer-based audit system compared the last platelet count or prothrombin time [expressed as percentage of normal clotting activity, prothrombin time (PT-%)] to predefined criteria. In the case of exceeding the preset thresholds, the system required additional information and recorded the pretransfusion laboratory values for later analysis. Thirty-two per cent of platelet transfusions were given with pretransfusion platelet count >49 x 10(9) L(-1), and 60% of these transfusions (19% of all platelet transfusions) could not be clinically justified in retrospective chart review. There was no significant change in this practice from P II to P III. FFP transfusions were given with significantly different pretransfusion PT-% values during P II and P III. The proportions of FFP transfusions with pretransfusion PT-% > 49% were 7.8% and 0.9% during P II and P III, respectively (P < 0.0001). In chart review, none of the FFP transfusions with pretransfusion PT-% > 49% could be justified by clinical grounds. Inappropriate transfusions of both platelets and plasma remain a significant challenge for quality assurance of neonatal intensive care. Automated recording of pretransfusion platelet count and prothrombin time reliably identified the poorly justified transfusions and thus offered a practical resource-saving tool for quality assurance of transfusion in the NICU. A significant shift towards more appropriate use of plasma was demonstrated after implementation of the audit system.

Prediction of outcome from the chest radiograph appearance on day 7 of very prematurely born infants

Our aim was to determine whether the chest radiograph appearance at 7 days predicted chronic lung disease development (oxygen dependency at 36 weeks post-menstrual age) or death before discharge and if it was a better predictor than readily available clinical data. Two consecutive studies were performed. In both, chest radiographs taken at 7 days for clinical purposes were assessed using a scoring system for the presence of fibrosis/interstitial shadows, cystic elements and hyperinflation and data were collected regarding gestational age, birth weight, use of antenatal steroids and post-natal surfactant and requirement for ventilation at 7 days. Oxygenation indices were calculated in the first study (study A) at 120 h and in the second (study B) at 168 h. In study A, there were 59 infants with a median gestational age of 26 weeks (range 24 to 28 weeks) and in study B, 40 infants with a median gestational age of 27 weeks (range 25-31 weeks). In both studies, infants who developed chronic lung disease had a significantly higher total chest radiograph score, with a higher score for fibrosis/interstitial shadowing than the rest of the cohort. Infants who died before discharge differed significantly from the rest with regard to significantly higher scores for cysts. In both studies, the areas under the receiver operator characteristic curves with regard to prediction of chronic lung disease were higher for the total chest radiograph score compared to those for readily available clinical data.

CONCLUSION

In infants who require a chest radiograph for clinical purposes at 7 days, the chest radiograph appearance can facilitate prediction of outcome of infants born very prematurely.

Early volume expansion 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, does early volume expansion reduce morbidity and mortality. If volume expansion is effective, what type of volume expansion is most effective.

SEARCH STRATEGY

The standard search strategy of the Neonatal Review Group was used. See Review Group details for more information. This was supplemented by additional searches of the Oxford Database of Perinatal Trials, and updated search performed of the Cochrane Central Register of Controlled Trials (CENTRAL, Cochrane Library Issue 1, 2004), MEDLINE (1996-January 2004), EMBASE (1980-January 2004), previous reviews including cross references (all articles referenced), abstracts and conferences (Perinatal Society of Australia and New Zealand, and Pediatric Academic Societies and American Academy of Pediatrics meetings 1998-2003).

SELECTION CRITERIA

Randomised trials of early volume expansion with normal saline, fresh frozen plasma, albumin, plasma substitutes or blood compared to no treatment or another form of volume expansion in preterm infants < 32 weeks gestation or < 1500g were included. Volume expansion was defined as at least 10 mls/kg given in the first 72 hours of life.

DATA COLLECTION AND ANALYSIS

Standard methods of the Neonatal Review Group with use of relative risk (RR), risk difference (RD) and weighted mean difference (WMD). The fixed effects model using RevMan 4.1 was used for meta-analysis. Data from individual studies were only eligible for inclusion if a least 80% of infants were reported for that outcome.

MAIN RESULTS

Seven studies were included. Five studies, four with data for mortality, compared volume to no treatment. Most studies enrolled very preterm infants on the basis of gestation or birthweight. Two studies comparing different types of volume expansion enrolled very preterm infants with hypotension. No study enrolled infants on the basis of low blood flow. One study examined the effect of volume expansion on blood flow but in normotensive very preterm infants. Comparing volume and no treatment, 4 studies with a total of 940 very preterm infants reported no significant difference in mortality (RR 1.11, 95% CI 0.88, 1.40). The large NNNI 1996 study reported no significant difference in severe disability (RR 0.80, 95% CI 0.52, 1.23), cerebral palsy (RR 0.76, 95% CI 0.48, 1.20) and combined death or severe disability (RR 1.00, 95% CI 0.80, 1.24). Although one small study (Beverley 1985) reported reduced P/IVH with volume expansion, this was not supported by any other study. No significant difference was reported in grade 3-4 P/IVH and combined death or grade 3-4 P/IVH. One study (NNNI 1996) reported no significant difference in the incidence of hypotension. The finding of decreased necrotising enterocolitis and increased sepsis in infants who received fresh frozen plasma compared to a gelatin-based plasma substitute or no treatment in one study should be treated with caution. No significant differences in mortality or disability were found in this study. Comparing albumin and saline in hypotensive infants, one study (Lynch 2002) reported a significant increase in mean BP and reduced incidence of treatment failure (persistent hypotension). The other study (So 1997) and the meta-analysis of the two studies found no significant difference in treatment failure (RR 0.75, 95% CI 0.53, 1.06) or in any other clinical outcome.

REVIEWERS' CONCLUSIONS

There is no evidence from randomised trials to support the routine use of early volume expansion in very preterm infants without cardiovascular compromise. There is insufficient evidence to determine whether infants with cardiovascular compromise benefit from volume expansion. There is insufficient evidence to determine what type of volume expansion should be used in preterm infants (if at all) or for the use of early red cell transfusions. The significance of the finding of a significant increase in blood pressure in hypotensive preterm infants in one trial comparing albumin and saline is unclear, but the overall meta-analyses found no other significant clinical benefit in using albumin compared to saline.

Current perspectives on the prevention and management of chronic lung disease in preterm infants

Chronic lung disease (CLD) or bronchopulmonary dysplasia is a recognized sequel of preterm birth. With improving survival of infants at lower gestational ages, the incidence is on the rise. Pathological features of CLD include alveolar maldevelopment, with or without areas of pulmonary fibrosis. Assisted ventilation, infection/inflammation, oxygen administration, and fluid overload are the major risk factors in the evolution of CLD.Interventions, including the treatment of maternal infection, administration of prenatal glucocorticoids, and postnatal surfactant replacement therapy, improve the survival of preterm infants; however, their effect on CLD is difficult to determine. Strategies that have been effective in reducing CLD are the administration of retinol (vitamin A), high frequency oscillatory ventilation, and administration of glucocorticoids. Previous concerns regarding neurological problems associated with high frequency ventilation have not been substantiated in recent studies. Current recommendations do not advise the routine use of glucocorticoids due to concerns regarding long-term neurodevelopment. Therapies that were found to be ineffective in reducing the incidence of CLD include prenatal thyrotropin, cromolyn sodium (sodium cromoglycate), alpha-1 antitrypsin, superoxide dismutase, tocopherol (vitamin E), ascorbic acid (vitamin C), allopurinol, ambroxol, inositol, inhaled bronchodilators, and fluid restriction. Strategies that may be effective in reducing lung injury and subsequent CLD include avoiding assisted ventilation, lung protective ventilatory maneuvers, permissive hypercapnia, prevention of infection, early aggressive nutrition, and the treatment of a patent ductus arteriosus. The use of inhaled glucocorticoids improves pulmonary dynamics but long-term effects are unknown. The management of infants with established CLD has not been studied adequately, and the role of various ventilatory strategies for infants with established CLD is not clear. Adequate oxygenation should be maintained to prevent hypoxic episodes. Diuretics are helpful during acute decompensation; however, their long-term impact has not been well studied. Provision of adequate nutrition, immunization (routine and against respiratory syncytial virus), follow-up, and monitoring are the key elements in the long-term management of infants with CLD. Future research priorities should be to identify strategies to prevent/treat inflammation and promote the healing processes in the injured lung. The long-term effects of lung-protective ventilation strategies need to be studied.

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.

Clinical implications of postnatal alterations in body water distribution

Substantial alterations take place in the quantity and distribution of body water compartments after birth. Clinical management must be tailored to the pace of postnatal adaptation, and the neonatal physician must be aware of these alterations in order to promote both normal physiological change and growth.

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.