Protective effect of vitamin E (DL-alpha-tocopherol) against intraventricular haemorrhage in premature babies

The Effectiveness of interventions to prevent intraventricular haemorrhage in premature infants: A systematic review and network meta-analysis

BACKGROUND

Intraventricular haemorrhage (IVH) is a common problem in preterm infants, being a major cause of morbidity and mortality. Despite many randomised controlled trials comparing interventions to prevent IVH, the best prevention remains unclear. This study aims to review all the interventions which intended to reduce the incidence of IVH and compare them in a network meta-analysis.

METHODS

A search on MEDLINE, EMBASE, Emcare, and CENTRAL was performed. Randomised controlled trials which evaluated neonatal interventions with a primary aim to reduce incidence of IVH in preterm infants were eligible. A surface under a cumulative ranking curve (SUCRA) was produced to indicate the intervention's likelihood of being the most effective for preventing IVH.

RESULTS

40 studies were eligible, enrolling over 6760 infants. Twelve intervention groups were found, including delayed cord clamping, erythropoietin, ethamsylate, fresh frozen plasma, heparin, ibuprofen, indomethacin, magnesium, nursing interventions, sedation, tranexamic acid, and vitamin E. Vitamin E and indomethacin had the highest probability of being the best interventions to prevent IVH in premature infants, but interpretation of these results is difficult due to study limitations.

CONCLUSION

Despite the impact of IVH, we were unable to identify a clearly beneficial treatment to reduce its incidence. Interpretation of the network meta-analysis was limited due to differences within studied populations, wide range of therapies trialled, and underlying advances in neonatal care between units, and over time. Although vitamin E and indomethacin appear to be promising candidates, contemporaneous trials of these, or novel agents, enrolling the most at-risk infants is needed urgently.

Periventricular- intraventricular hemorrhage in the premature infant- A historical perspective

The objective of this chapter is to trace the evolution of intraventricular hemorrhage in the premature infant highlighting the importance of the germinal matrix, a critical role for cerebral blood flow changes in the genesis of hemorrhage, clinical factors that increase the bleeding risk, and potential preventative strategies. In 1976, neuropathological studies demonstrated capillary rupture within the germinal matrix as the precursor of hemorrhage. In 1980, introduction of cranial ultrasound facilitated diagnosis of intraventricular hemorrhage. In 1979, loss of cerebral autoregulation in sick newborn infants was demonstrated. In the 1980's, studies demonstrated the importance of intravascular factors in provoking hemorrhage. In 1983, the association of cerebral blood flow velocity fluctuations and subsequent hemorrhage was demonstrated. In 1994, antenatal steroids use to accelerate lung development was recommended. This was associated with an unanticipated reduction in hemorrhage. In the mid 1990's early indomethacin administration was associated with a reduction of severe hemorrhage.

GC-MS Analysis of Bioactive Compounds of Flower Extracts of Calycopteris floribunda Lam.: A Multi Potent Medicinal Plant

Calycopteris floribunda Lam. is a potent medicinal woody climber that belongs to Combretaceae. This plant is usually found in dry deciduous tropical forests and is used in various medicinal practices like Ayurveda, Unani and Sidda. Whole plant and its different parts like leaves, flowers and stem are used in the treatment of diarrhoea, dysentery, jaundice and malaria. It is also have anthelminthic, anti-inflammatory, antifungal, hepatoprotective and anticancerous activities. Knowing its medicinal properties, the present study is undertaken to investigate the preliminary phytochemical constituents and bioactive compounds of flower extracts by GC-MS. GC-MS analysis of flower extracts revealed the presence of over all 41 compounds, of which, acetone and ethanol extracts showed the presence of 13 compounds each, chloroform extract 8 and petroleum ether extract 7 compounds. Some compounds were common in two and three extracts only. The significant bioactive compounds identified are 1,2-benzenedicarboxylic acid (59.81%) in chloroform extract, triterpene lupeol (34.98%) in ethanol extract, tetratetracontane (26.99%) in petroleum ether extract and gamma sitosterol (22.04%) in acetone extract.

Vitamin E and preterm infants

In evaluating vitamin E (VE) nutritional status of preterm infants, it is essential that any data should be compared with those of healthy term infants, and never with those of adults. Moreover, it should be evaluated in terms of gestational age (GA), not birth weight (BW), because placental transfer of most nutrients from mother to fetus is dependent on GA, not BW. Judging from the limited data during the last 75 years, there was no significant correlation between GA and VE concentrations in circulation or in the red blood cells (RBCs), leukocytes, and buccal mucosal cells. In addition, the oxidizability of polyunsaturated fatty acids (PUFAs) in plasma or RBCs, as targets for protection by VE chain-breaking ability, was lower in preterm infants. However, because of the minimal information available about hepatic VE levels, which is considered a key determinant of whole body VE status, the decision on whether VE status of preterm infants is comparable with that of term infants should be postponed. Clinical trials of VE supplementation in preterm infants were repeatedly undertaken to investigate whether VE reduces severity or inhibits development of several diseases specific to preterm infants, namely retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD), and germinal matrix hemorrhage - intraventricular hemorrhage (GMH-IVH). Most of these trials resulted in a misfire, with a few exceptions for IVH prevention. However, almost all these studies were performed from 1980s to early 1990s, in the pre-surfactant era, and the study populations were composed of mid-preterm infants with GAs of approximately 30 weeks (wks). There is considerable difference in 'preterm infants' between the pre- and post-surfactant eras; modern neonatal medicine mainly treats preterm infants of 28 wks GA or less. Therefore, these results are difficult to apply in modern neonatal care. Before considering new trials of VE supplementation, we should fully understand modern neonatal medicine, especially the recent method of oxygen supplementation. Additionally, a deeper understanding of recent progress in pathophysiology and therapies for possible target diseases is necessary to decide whether VE administration is still worth re-challenging in modern neonatal intensive care units (NICUs). In this review, we present recent concepts and therapeutic trends in ROP, BPD, and GMH-IVH for those unfamiliar with neonatal medicine. Numerous studies have reported the possible involvement of reactive oxygen species (ROS)-induced damage in relation to supplemental oxygen use, inflammation, and immature antioxidant defense in the development of both BPD and ROP. Various antioxidants effectively prevented the exacerbation of BPD and ROP in animal models. In the future, VE should be re-attempted as a complementary factor in combination with various therapies for BPD, ROP, and GMH-IVH. Because VE is a natural and safe supplement, we are certain that it will attract attention again in preterm medicine.

Comparative analysis of the seasonal influence on polyphenolic content, antioxidant capacity, identification of bioactive constituents and hepatoprotective biomarkers by in silico docking analysis in Premna integrifolia L

The present study reports the effect of different seasons on polyphenol content and antioxidant potential of ethanolic, methanolic, ethyl acetate, and aqueous extracts of leaves, stems, and roots of Premna integrifolia. Ethyl acetate extract of leaves (EAEPI) collected in the rainy season showed potent antioxidant activity with highest total phenol (74.33 ± 2.26 µg/mg, gallic acid equivalent), and flavonoid (98.83 ± 0.26 µg/mg, rutin equivalent) content. Therefore, EAEPI extract was subjected to characterization by UHPLC-Q-TOF-MS/MS and GC-MS analysis for the identification of active constituents. UHPLC-Q-TOF-MS/MS analysis in + ve ion mode revealed the presence of eight polyphenolic compounds namely quercetin-3-D-xyloside, kaempferol-3,7-O-bis-alpha-L-rhamnoside, isorhamnetin-3-Oglucoside, luteolin-3',7-di-O-glucoside, eriodictyol-7-O-glucoside, syringetin-3-O-galactoside, petunidin-3-O-beta-glucopyranoside and vitexin-2″-O-rhamnoside. GC-MS analysis confirmed the presence of 26 compounds with six major compounds viz; citronellol, phytol acetate, campesterol, squalene, stigmasterol, and hexadecanoic acid. These compounds are reported for the first time from P. integrifolia except phytol and stigmasterol. Our previous study validates the hepatoprotective potential of P. integrifolia but there was no idea about the bioactive compound responsible for the activity. So, in present work, the major compounds identified in spectrometry analysis were subjected to in silico docking against an important liver enzyme alanine amino transaminase to confirm its hepatoprotective properties. Docking analysis validates the presence of two hepatoprotective lead compounds stigmasterol, and campesterol, which satisfy the drug-likeness criteria with good absorption, distribution, metabolism, and toxicity properties. Thus, present work gives a clear insight about the influence of season on the total polyphenolic constituent in different plant parts of P. integrifolia, their antioxidant potential and preclinical evaluation of hepatoprotective lead compounds.

Effect of Vitamin E in Prevention of Intraventricular Hemorrhage in Preterm Neonates

Background

Germinal matrix-intraventricular hemorrhage (IVH) is the most common brain hemorrhage in preterm neonates. The importance of this hemorrhage lies in its severe complications. There is no definite treatment for IVH in neonates; therefore, the prevention of IVH should be considered. Some studies have shown that Vitamin E can probably decrease the risk of IVH and the other study has not shown its efficacy. The aim of this study is to evaluate the effects of Vitamin E on incidence and severity of IVH in preterm neonates.

Methods

This study is a randomized clinical trial conducted on 76 neonates with gestational age of ≤30 weeks in the Isfahan University of Medical Science. The neonates were divided into two groups. The group one was administered with 10 units of Vitamin E for 3 days and the second group with placebo. In the 4th and 7th days after birth, brain sonography was conducted to evaluate IVH. The presence of sepsis, incidence of necrotizing enterocolitis, and hypotension were examined.

Results

In this study, 76 neonates with the mean age of 28.49 ± 1.46 weeks participated. The incidence of hemorrhage in the 4th day was 26.3% in cases and 42.1% in controls with no significant difference (P = 0.3). The findings of the second sonography reported the incidence of IVH in 17.1% of cases and 36.8% of control group.

Conclusions

Based on findings of the current study, Vitamin E use did not significantly decrease IVH in neonates. Further studies with larger sample size are needed.

Serum tocopherol levels in very preterm infants after a single dose of vitamin E at birth

OBJECTIVE

Our aim was to examine the impact of a single enteral dose of vitamin E on serum tocopherol levels. The study was undertaken to see whether a single dose of vitamin E soon after birth can rapidly increase the low α-tocopherol levels seen in very preterm infants. If so, this intervention could be tested as a means of reducing the risk of intracranial hemorrhage.

METHODS

Ninety-three infants <27 weeks' gestation and <1000 g were randomly assigned to receive a single dose of vitamin E or placebo by gastric tube within 4 hours of birth. The vitamin E group received 50 IU/kg of vitamin E as dl-α-tocopheryl acetate (Aquasol E). The placebo group received sterile water. Blood samples were taken for measurement of serum tocopherol levels by high-performance liquid chromatography before dosing and 24 hours and 7 days after dosing.

RESULTS

Eighty-eight infants received the study drug and were included in the analyses. The α-tocopherol levels were similar between the groups at baseline but higher in the vitamin E group at 24 hours (median 0.63 mg/dL vs. 0.42 mg/dL, P = .003) and 7 days (2.21 mg/dL vs 1.86 mg/dL, P = .04). There were no differences between groups in γ-tocopherol levels. At 24 hours, 30% of vitamin E infants and 62% of placebo infants had α-tocopherol levels <0.5 mg/dL.

CONCLUSIONS

A 50-IU/kg dose of vitamin E raised serum α-tocopherol levels, but to consistently achieve α-tocopherol levels >0.5 mg/dL, a higher dose or several doses of vitamin E may be needed.

Intracranial hemorrhage in the preterm infant: understanding it, preventing it

New discoveries in neonatal imaging, cerebral monitoring, and hemodynamics, and greater understanding of inflammatory and genetic mechanisms involved in intracranial hemorrhage (ICH) in the preterm infant are creating opportunities for innovative early detection and prevention approaches. This article covers the spectrum of ICH in the preterm infant, including germinal matrix intraventricular hemorrhage, its complications, and associated phenomena, such as the emerging role of cerebellar hemorrhage. The overall aim of this article is to review the current knowledge of the mechanisms, diagnosis, outcome, and management of preterm ICH; to revisit the origins from which they develop; and to discuss future expectations.

Intraventricular haemorrhage and posthaemorrhagic hydrocephalus: pathogenesis, prevention and future interventions

Intraventricular haemorrhage (IVH) is still a major complication of preterm birth with serious disability resulting. The fragile blood vessels in the germinal matrix below the ventricular lining and the instability of blood flow to this highly vascular area are the main mechanisms behind IVH. There is good evidence that corticosteroid therapy before preterm delivery reduces mortality and IVH substantially with a trend towards a reduction in disability. There is good evidence that postnatal indomethacin reduces IVH but no evidence that mortality or disability is reduced. There is evidence that stabilizing cerebral blood flow with pancuronium in infants with respiratory distress reduces IVH in the minority of infants with marked fluctuations. There is limited evidence that postnatal vitamin E and ethamsylate reduce IVH but insufficient evidence of reduced mortality or disability. Hydrocephalus following IVH results initially from multiple small blood clots throughout the CSF channels impeding circulation and re-absorption. Transforming growth factor beta is released into the CSF and there is mounting evidence that this cytokine stimulates the laying down of extracellular matrix proteins such as laminin and fibronectin which produce permanent obstruction to the CSF pathways. Interventions such as early lumbar punctures, diuretic drugs to reduce CSF production and intraventricular fibrinolytic therapy have been tested and, not only fail to prevent shunt dependence, death or disability, but have significant adverse effects. Surgical interventions such as subcutaneous reservoir and external drain have not been subject to controlled trial. Ventriculoperitoneal shunt is not feasible in the early phase after IVH but, despite the problems with blockages and infections, remains the only option for infants with excessive head expansion over periods of weeks. New treatment approaches aimed at preventing hydrocephalus are needed.

Intraventricular hemorrhage: emphasis on prevention

Germinal matrix/intraventricular hemorrhage is a common type of cerebral injury in premature newborns. Based on the improved understanding of underlying pathogenetic mechanisms, numerous interventional strategies for prevention have been proposed. This article summarizes and evaluates the efficacy and safety of major interventions that are currently under consideration for the prevention of germinal matrix/intraventricular hemorrhage.

Breath pentane as a marker for lipid peroxidation and adverse outcome in preterm infants

AIM

To test the hypothesis that complications of neonatal intensive care are related to increased oxygen derived free radical activity, using breath pentane as a marker of lipid peroxidation.

METHODS

Exhaled breath was collected daily from 57 ventilated preterm infants and pentane concentration measured by gas chromatography.

RESULTS

High peak pentane exhalation was significantly associated with low gestational age, mortality, intraventricular haemorrhage and retinopathy of prematurity. Peak pentane was not significantly associated with the development of chronic lung disease.

CONCLUSIONS

The demonstration that pentane exhalation is related to the course of neonatal disease and its outcome is consistent with the hypothesis that lipid peroxidation is associated with these illnesses, and may contribute to their severity. If this is a causal relation, antioxidant treatments could prove useful in reducing their severity. Measurement of breath pentane might assist in the assessment of antioxidant strategies prior to more extensive clinical trials.

Vitamin E prophylaxis to reduce retinopathy of prematurity: a reappraisal of published trials

OBJECTIVE

We conducted a meta-analysis of the published randomized clinical trials of vitamin E prophylaxis designed to reduce retinopathy of prematurity (ROP) to determine whether increased serum concentrations of vitamin E reduced the incidence of severe, threshold (Stage 3+) ROP in the very low birth weight (VLBW) infant subset.

STUDY DESIGN

Among the six trials considered eligible for analyses, the incidence for all stages of ROP and for Stage 3+ ROP was computed for all randomly assigned infants (intention-to-treat analysis) and for those infants completing the trials. Odds ratios (ORs) and pooled estimates for event rate reductions (and the respective 95% confidence intervals [CIs]) were calculated for these outcome end points.

RESULTS

There were 704 VLBW infants in the vitamin E prophylaxis groups and 714 in control groups; 536 (76.1%) infants in the vitamin E and 551 (77.2%) in the control groups completed the trials. In all trials the mean serum vitamin E concentrations were within or above the physiologic range in the vitamin-treated groups and at or below the physiologic ranges in the control groups. The overall incidence of any stage ROP was similar between the groups: 39.8% in the vitamin E group and 43.5% in the control group. The overall incidence for Stage 3+ ROP was lower in the vitamin E-treated groups than in the control group (2.4% in vitamin E vs 5.3% in control). The pooled OR for developing Stage 3+ ROP with vitamin E prophylaxis was 0.44 (95% CI, 0.21, 0.81, p < 0.02). The reciprocal of the pooled estimate of mean risk reduction (2.8%, 95% CI: 0.55%, 5.1%) for Stage 3+ ROP revealed that on average, vitamin E prophylaxis given to 35 VLBW infants would prevent one case of threshold, Stage 3+ ROP.

CONCLUSIONS

Considering that there was a 52% reduction in the incidence of Stage 3+ ROP, we suggest that the role of vitamin E in reducing severe ROP be re-evaluated. We could not assess the adverse effect rates from vitamin E therapy in the trials analyzed; therefore, we recommend a well-controlled and focused trial in which the issues of benefit, adverse effects, and cost can be assessed with vitamin E prophylaxis in extremely low birth weight (< 1000 gm) infants.

Neonatal nutritional requirements and formula composition: a review

Adequate neonatal nutrition is essential for appropriate growth and avoidance of complications associated with deficiencies. Neonatal nutritional requirements vary with metabolic states, degree of prematurity, and diseases affecting the gastrointestinal, pulmonary, and cardiac systems. Differences exist between formula brands for protein, fat, and carbohydrate sources. Differences also exist between formulas designed for preterm and full-term infants, as well as infants with special nutritional needs. Optimal nutrition should be a consistent goal for each infant, whether in a healthy newborn nursery, intensive-care unit, or home care setting. Nurses must be aware of the possibilities available to address the special needs of infants.

Prevention of intraventricular hemorrhage in preterm infants

Prematurely born infants with intraventricular hemorrhage (IVH) suffer significant morbidity and mortality, particularly those infants with high grade hemorrhage. The more premature infants have a higher incidence, experiencing more severe IVH. Early onset IVH is also likely to be severe and to progress to a higher grade. The etiology of intraventricular hemorrhages is clearly multifactorial, with differing sets of risk factors for early onset and later occurring hemorrhage. Prevention requires multilayered strategies, both prenatal and postnatal. These strategies are discussed in detail, highlighting unresolved controversies. Certain recommendations for prevention can be made. These include efforts to prevent preterm delivery, transfer of high risk mothers to tertiary care centers and antenatal maternal steroid use. Postnatally, the importance of optimal resuscitation and neonatal care practices is stressed, particularly those which minimize cerebral blood flow fluctuation. Postnatal indomethacin use should be considered in most infants. Further investigation of other strategies is necessary, including multicenter randomized trials to further evaluate antenatal pharmacologic agents, as well as the relative efficacy of different modes of delivery. The different risk factors for early onset versus later onset IVH must be more clearly delineated. Most importantly, any strategy must include sustained neurodevelopmental followup.

Vitamin E supplementation in the critically ill patient: too narrow a view?

Oxidative stress plays an important contributory role in a number of diseases. In critically ill patients, oxidative stress is a major problem that results from a number of compounding factors such as supportive oxygen therapy, pulmonary inflammation, and the nutritional inadequacies of these patients. It has been known for some time that the circulating concentration of vitamin E, the primary lipid-soluble antioxidant, is low in critically ill patients. However, supplementation with vitamin E by oral loading has not been successful in improving clinical status. A better understanding of the bioavailability of vitamin E in these patients and of the synergistic action of other antioxidant nutrients such as vitamin C and glutathione with vitamin E has provided new opportunities to reexamine the use of antioxidant supplementation for the critically ill.

Intraventricular Hemorrhage: An Update

Although the incidence of intraventricular hemorrhage (IVH) has decreased in recent years, the increasing survival rates for the smallest premature infants indicate that the lesion will continue to be a major problem in neonatal intensive care facilities. We review prenatal, perinatal, and postnatal variables that have been associated with enhanced risk of IVH and address some of the methodological limitations of previously reported studies. The neuropa-thology is characterized by bleeding into the subependymal germinal matrix, with subsequent rupture into the lateral ventricle. The pathogenesis of IVH relates to intravascular, vascular, and extravascular factors. Intravas-cular factors are those that relate primarily to control of blood flow and pressure in the microcirculation of the germinal matrix. Vascular factors relate to the microcirculation of the matrix, the site of initial bleeding. A maturation-dependent alteration of vascular integrity and a vulnerability of matrix vessels to injury appear important. Extravascular factors include those relevant to mesenchy-mal and glial support for matrix vessels and to local fibrino-lytic activity in the germinal matrix. Prognosis in the setting of IVH relates to the mechanisms of brain injury, the most important of which is pcriventricular hemorrhagic infarction, often inappropriately called grade IV IVH and often associated with subsequent motor and cognitive deficits. Prevention of IVH remains the most important goal. Prenatal interventions include prevention of premature birth, transportation of premature infants to a tertiary facility in utero rather than after birth, possibly prenatal administration of phenobarbital or vitamin K, and optimal management of labor and deliver. Postnatal interventions include careful newborn resuscitation, correction or prevention of major hemodynamic disturbances, and correction of abnormalities of coagulation. Postnatal pharmacological interventions that have been studied in detail include phenobarbital, indomethacin, ethamsylate, and vitamin E. No single agent among this group has been shown consistently to lead to a decrease in incidence and severity of IVH.

Dietary supplementation of vitamin E fails to prevent the development of hyperoxic lung injury in the premature guinea pig

1. The benefit of dietary vitamin E supplementation in preventing oxidative-induced lung injury was investigated. Three day preterm guinea pig pups were exposed to hyperoxic (85% O2) or normoxic (21% O2) conditions. The animals were fed either a standard low birthweight human infant formula milk (6.4 mg/l vitamin E), or a vitamin E supplemented milk (100 mg/l) for up to 7 days. 2. After 3 days vitamin E supplementation, plasma but not erythrocyte vitamin E concentrations were elevated, while following 7 days both plasma and erythrocyte vitamin E concentrations were significantly increased. 3. Lung and liver vitamin E concentrations were elevated at both 3 and 7 days. At 3 days the increase in lung vitamin E was oxygen-dependent, suggesting that the lung increases uptake of vitamin E in response to oxidative stress. 4. Despite an increase in the vitamin E concentration of the lungs of preterm guinea pigs, no amelioration of the lung injury was observed. These results suggest that although vitamin E is a potent antioxidant, it is unable to protect adequately the lungs from reactive oxygen species in the absence of sufficient primary enzymatic antioxidant defences.

Pharmacologic management of neonatal cerebral ischemia and hemorrhage: old and new directions

New developments in pharmacologic management of cerebral ischemia and hemorrhage are reviewed. A number of agents with diverse modes of action have now been shown to be neuroprotective in adult and neonatal animal models when administered either before or after a hypoxic-ischemic insult. As experience improves with these agents in hypoxic-ischemic injury and periventricular-intraventricular hemorrhage in human neonates, there is reason to be optimistic that effective neuroprotective strategies will soon be clinically available.

Indomethacin promotes germinal matrix microvessel maturation in the newborn beagle pup

BACKGROUND AND PURPOSE

Although indomethacin has been demonstrated to prevent germinal matrix and intraventricular hemorrhage in clinical and animal studies, the mechanism of action of this agent to prevent hemorrhage remains unclear. Previous studies have demonstrated both that the microvessels in the germinal matrix of newborn beagle pups undergo basement membrane maturation during the first 4 postnatal days and that indomethacin may promote laminin deposition in tumor cell culture systems.

METHODS

We employed the newborn beagle pup model to test the hypothesis that indomethacin may stimulate laminin deposition in germinal matrix microvessels. Newborn pups were randomized to receive either 0.1 mg/kg/dose i.p. indomethacin or an equal volume of saline diluent. Pups received doses of study medication once a day for 1, 2, or 3 days and were studied on postnatal days 1, 2, 3, or 4. Pups were anesthetized and systemically perfused with buffered formalin; the brains were removed and prepared for immunohistochemical study.

RESULTS

Sections stained with Bandeiraea lectin demonstrated that there was no difference in germinal matrix vessel density among the postnatal ages studied; similarly, there were no differences in vessel density between saline- and indomethacin-treated animals at any postnatal age. Quantification of germinal matrix stained intensity by confocal microscopy demonstrated significant increases in indomethacin-treated pups for both laminin staining at postnatal days 2 (p = 0.05) and 3 (p = 0.0009) and type V collagen staining at postnatal day 2 (p = 0.011). Although staining for beta 1 integrins increased across postnatal ages, there were no differences between saline- and indomethacin-treated animals.

CONCLUSIONS

These data suggest that indomethacin may stimulate basement membrane deposition in the germinal matrix microvessels of newborn beagle pups to prevent germinal matrix and/or intraventricular hemorrhage.

Tissue alpha-tocopherol status during late fetal and early neonatal life of the guinea-pig

The alpha-tocopherol content of a number of different fetal, neonatal and maternal guinea-pig tissues was determined and compared with plasma and erythrocyte alpha-tocopherol values. During late gestation, the fetal liver appears to act as a storage site for alpha-tocopherol, the majority of which is released immediately following birth. In contrast, lung and brain vitamin E levels are relatively constant over the final period of gestation and during early neonatal life. The ontogeny of alpha-tocopherol in brain and lung was similar to that for erythrocytes while plasma alpha-tocopherol content varied considerably and did not accurately reflect tissue alpha-tocopherol status. Surprisingly, fetal and maternal lung alpha-tocopherol concentrations were similar at all time-points considered, whereas fetal liver alpha-tocopherol status was always considerably greater than maternal liver alpha-tocopherol content. These results, if representative of the human fetus, suggest that preterm infants may not have tissue alpha-tocopherol concentrations as low as previously assumed and that during the perinatal period erythrocyte alpha-tocopherol content is a more accurate indicator of tissue alpha-tocopherol concentration than plasma alpha-tocopherol content.

Etiologic factors and pathologic alterations in selenium-vitamin E deficiency and excess in animals and humans

The etiology of selenium-vitamin E (Se-E) deficiency diseases may be complex. Many of the syndromes involve combined deficiency of selenium and vitamin E. Selenium moves into the animal and human food chain from soil and plants, which may contain inadequate amounts of the nutrient in many areas of the world. Vitamin E may be in low concentration in many animal feeds unless supplements are added. Some syndromes, such as steatitis in cats, result from an increased requirement of vitamin E in diets that contain large amounts of polyunsaturated fatty acids, and these diseases will only respond to vitamin E administration. Deficiency syndromes in animals owing to pure Se deficiency are infrequent and have been produced mainly by laboratory studies utilizing extreme deficiency conditions. Other factors that may affect the occurrence of these deficiency diseases are concurrent dietary deficiency of S-containing amino acids, bioavailability of different forms of dietary Se, intake of compounds that antagonize Se (e.g., silver salts), and exposure to various prooxidant substances (e.g., iron compounds, oxygen, ozone, and various drugs).

Vitamin E therapy in retinopathy of prematurity

Vitamin E is a fat soluble antioxidant and as a result it is able to scavenge free radicals derived from oxygen. The premature infant and the retina are likely to be particularly vulnerable to the deleterious effects of these oxygen derived free radicals, and as a result prophylactic vitamin E has been suggested for the management of retinopathy of prematurity (ROP). However, despite numerous trials, prophylactic supplementation with vitamin E remains controversial. This paper will critically review the use of vitamin E in ROP and consider the risk/benefit relationship of such treatment in premature infants.

Prevention and treatment of postasphyxial cerebral damage

Prevention and treatment of postasphyxial, i.e. hypoxic-ischemic, brain damage can be considered at various levels or stages of the process. The first approach is based on epidemiological studies, which typically allow the delineation of risk factors for cerebral damage. By trying to eliminate or reduce such factors, one may influence the incidence of the disorder. At the second stage, the actual pathogenetic mechanisms, e.g. hypoxia or hypotension, leading to brain damage may be preventable or treatable. Finally, limiting the extent of the lesion immediately after the event may be possible.

Is routine vitamin E administration justified in very low-birthweight infants?

Analysis of nine randomised controlled trials of prophylactic vitamin E supplementation in very low-birthweight infants (less than 1500g) showed no statistically significant reduction in the incidence of acute retinopathy of prematurity. There was a significant reduction (49 per cent) in the incidence of intraventricular haemorrhage, but no clear evidence for a corresponding reduction in intracerebral haemorrhage and no reduction in the incidence of haemorrhage confined to the germinal matrix. By combining the estimated reduction with the known incidence of long-term neurological disability associated with intracranial haemorrhage alone, it was shown that only 1.5 per cent (point estimate) and not more than about 4 per cent of all very low-birthweight infants are likely to benefit from routine vitamin E supplementation. In view of this, and data suggesting toxicity of vitamin E at concentrations close to those considered therapeutic, the routine use of vitamin E in very low-birthweight infants is not justified on present evidence. Only large randomised trials can establish whether currently used vitamin E preparations do more good than harm.

Results of surgical treatment of neonatal necrotizing enterocolitis

In 6 years, 74 neonates were treated for necrotizing enterocolitis, 40 (54 per cent) of whom underwent operation. The early postoperative mortality rate was 23 per cent and there was one late death. Of the 30 postoperative survivors, two have short bowel syndrome, two have chronic respiratory disease, two are partially sighted, and five (17 per cent) have severe developmental delay. Only 15 (50 per cent) survivors enjoy good health.

Iron nutrition in childhood: the interplay of genes, development and environment

The state of a child's iron nutrition depends on his genetic endowment, the stage of development he has reached and the environment in which he lives. Genetic disorders lead more commonly to iron overload than to deficiency. Generally interplay between genes and environment is apparently of little importance when considering iron deficiency; are we missing something? The greatest demands for iron are at the time of most rapid growth, i.e. during infancy and puberty, but during early infancy body stores can meet the demand without a need for dietary iron. Oxygen, diet and microbes are the important environmental factors related to iron nutrition. The relationship of oxygen toxicity to iron nutrition in the newborn has received only fleeting study, the availability of iron from many foods is unclear; the clinical significance of iron overload and deficiency in the evolution of an infection is also unclear despite a wealth of in vitro observation. I am not convinced that the bottle fed baby should receive iron in his diet during the first 4-6 months of life. Thereafter, while the concept of universal unselective supplementation causes some uneasiness there are considerable epidemiological arguments for fortification of food with iron.

Intraventricular hemorrhage in the premature infant--current concepts. Part II

Diagnosis of periventricular-intraventricular hemorrhage (IVH) and its neuropathological consequences and accompaniments in the living infant has been facilitated greatly by the introduction of real-time cranial ultrasonography. The major advantages of the technique include high-resolution capability, portable instrumentation, lack of ionizing radiation, and relative affordability. Prognosis in infants with IVH relates to the mechanisms of brain injury, the most important of which are prior hypoxic-ischemic insults, posthemorrhagic hydrocephalus, and periventricular hemorrhagic infarction. The last of these is most critical and it is now clear that careful quantitative assessment of the ultrasonographic appearance of the periventricular parenchyma in the infant with IVH during the acute period of illness is of major value in estimating outcome. Prevention of IVH remains the most important goal. Prenatal interventions include prevention of premature birth (currently a very elusive goal in the United States), transportation of the premature infant to a tertiary facility in utero rather than after birth (an approach of proven value), prenatal administration of phenobarbital or vitamin K (initially promising data that require confirmation and amplification), and optimal management of labor and delivery. Postnatal interventions include careful resuscitation of newborns, correction of fluctuating cerebral blood flow velocity, correction or prevention of other major hemodynamic disturbances, and correction of abnormalities of coagulation. Of these interventions the use of muscle paralysis to correct fluctuating cerebral blood flow velocity has shown the most striking benefit vis-à-vis prevention of IVH. Postnatal pharmacological interventions that have been studied in detail include the use of phenobarbital, indomethacin, ethamsylate, and vitamin E. No single agent among this group has been shown consistently to lead to a decrease in incidence and severity of IVH.(ABSTRACT TRUNCATED AT 250 WORDS)

Randomized low-dose indomethacin trial for prevention of intraventricular hemorrhage in very low birth weight neonates

We admitted 36 preterm neonates (600 to 1250 gm birth weight) with normal 6-hour echoencephalograms to a randomized, placebo-controlled prospective trial to determine whether a low dose of indomethacin would prevent germinal matrix or intraventricular hemorrhage and permit adequate urinary output. Between the sixth and tenth postnatal hours, indomethacin (0.1 mg/kg) or placebo was administered intravenously every 24 hours for a total of three doses. Cardiac ultrasound studies to assess the status of the ductus arteriosus were performed at 6 postnatal hours and on day 5. Urinary output, serum electrolytes, serum indomethacin levels, and renal and clotting functions were monitored. No differences in birth weight, gestational age, or Apgar scores were noted between the two groups of infants. Two indomethacin-treated infants and three infants given placebo had significant urinary output difficulties, requiring that the study medication be withheld. Of 19 infants given indomethacin, two had germinal matrix or intraventricular hemorrhage, in comparison with 8 of 17 infants given saline solution (p = 0.02). Of the infants who had a left-to-right patent ductus arteriosus shunt before treatment, 64% of the indomethacin-treated and 33% of the saline solution-treated infants no longer had a patent ductus arteriosus on day 5. Ductal status appeared unrelated to the development of germinal matrix or intraventricular hemorrhage.

Understanding and preventing perinatal, intracerebral, peri- and intraventricular hemorrhage

Antenatal anticipation of problem pregnancies and improvements in resuscitation and care of newborns have led to increasing survival of babies born prematurely. Nevertheless, the potential for neurologic handicaps is significant in this population of children, and the prevention of intracerebral, peri- and intraventricular hemorrhages and associated brain lesions remains a high priority. In this review, we consider the clinical problem of periventricular, intraventricular hemorrhage; means of diagnosis; the EEG and periventricular, intraventricular hemorrhage; sequelae; hypotheses of pathogenesis; experimental approaches to understanding periventricular, intraventricular hemorrhage; agents being tested for use in preventing hemorrhage; and future areas for research toward the prevention of hemorrhage and other neonatal brain lesions.

Vitamin E supplementation reduces frequency of periventricular haemorrhage in very preterm babies

231 babies, born at less than or equal to 32 weeks' gestation were enrolled in a randomised, controlled trial to assess the efficacy of vitamin E (dl-alpha-tocopherol acetate) in the prevention of periventricular haemorrhage. Daily supplementation with 20 mg/kg vitamin E intramuscularly during the first 3 days of life was associated with a rise in plasma vitamin E concentration and a reduction in hydrogen peroxide haemolysis of red blood cells in vitro. Among babies without haemorrhage on entry to the trial (n = 210), supplemented babies had a lower frequency of intraventricular haemorrhage than controls (8.8% v 34.3%; p less than 0.005) and a lower combined frequency of intraventricular and parenchymal haemorrhage (10.8% v 40.7%; p less than 0.0001) on the final ultrasound brain scan. This protective effect was observed in both inborn and referred babies but was stronger in the former. Supplementation had no effect on mortality, but among survivors fewer supplemented babies than controls had intraventricular or parenchymal haemorrhage (10.7% v 32.6%; p less than 0.001). Possibly, vitamin E scavenges free radicals generated during ischaemic injury of the subependymal region and thereby limits tissue damage and the extent of periventricular haemorrhage on reperfusion.

Serum alpha-tocopherol levels after high-dose enteral vitamin E administration in patients with acute respiratory failure

Serum levels of tocopherols were measured in 5 healthy volunteers and in 14 patients with acute respiratory failure before and after onset of high-dose enteral vitamin E administration. The initial alpha-tocopherol levels did not differ between both groups (12.1 +/- 2.7 micrograms/ml in the volunteers and 11.3 +/- 3.5 micrograms/ml in the patients; mean +/- SD). After oral administration of 1 g d,l-alpha-tocopherylacetate per day the serum levels more than doubled within 1 day and reached a plateau between 22 and 30 micrograms/ml after 3 days in the volunteers. In contrast, application of even 3 g vitamin E/day by gastric tube in the patients with respiratory failure caused only a delayed increase of the serum levels with values nearly doubling after 5-10 days (6 patients), or there was no increase at all (8 patients). Serum alpha-tocopherol did not rise in patients without accompanying highmolecular weight formula diet and in patients with prolonged hemodynamic insufficiency and metabolic acidosis. The age of the patients, the fact of severe blood losses, hemodialysis and hemofiltration and the final outcome of death or survival appeared to be without influence on the response to enteral vitamin application. Neither in the volunteers nor in the patients with acute respiratory failure were there any detectable amounts of beta-, gamma- or delta-tocopherol or of alpha-tocopherolquinone or alpha-tocotrienol.

Multicentre trial of ethamsylate for prevention of periventricular haemorrhage in very low birthweight infants

The effectiveness of ethamsylate in the prevention of periventricular haemorrhage (PVH) in very low birthweight infants was evaluated by means of a multicentre, placebo-controlled, double-blind trial. In 330 infants without evidence of PVH on initial cranial ultrasound examination there was little difference between ethamsylate and placebo groups with respect to subependymal haemorrhage, but intraventricular and parenchymal haemorrhages developed in 30/162 infants (18.5%) in the treated group, compared with 50/168 (29.8%) in the control group (p less than 0.02). The incidence of intraventricular and parenchymal haemorrhage in survivors was 20/137 (14.6%) in the ethamsylate group and 37/146 (25.3%) in the controls (p less than 0.05). In 30 infants with evidence of PVH on the initial scan, ethamsylate treatment seemed to limit parenchymal extension. Analysis of the total cohort of 360 infants showed that the proportion of infants in whom an increase of two or more grades of severity of PVH was recorded during the trial was lower in the treated than in the placebo group (p less than 0.01). No adverse effects were attributed to ethamsylate therapy. The reported incidence of patent ductus arterious was lower in the treated than in the placebo group (p less than 0.02). Mortality was similar in the two groups.

Ethamsylate reduces immunoreactive prostacyclin metabolite in low birthweight infants with respiratory distress syndrome

Measurement of 6 ketoprostaglandin F1 alpha was made by radioimmunoassay during the first 3 days of life in 33 infants with respiratory distress syndrome who were subjects in a double blind controlled trial of ethamsylate for the prevention of intraventricular haemorrhage. Levels of 6-ketoprostaglandin F1 alpha were significantly lower on the first and second days of life in babies receiving ethamsylate. There was a reduction in the incidence of intraventricular haemorrhage in the treated group. High levels of prostacyclin metabolite are found in babies who develop haemorrhage, and reduction of prostacyclin synthetase activity may be the mode of action of this drug in vivo.

Periventricular haemorrhage and leukomalacia in extremely low birthweight infants

Forty (49%) of 82 extremely low birthweight (ELBW, less than 1000 g) infants had periventricular haemorrhage (PVH). Ten (12%) had germinal layer haemorrhage (GLH) alone, 16 (20%) had intraventricular haemorrhage (IVH) and 14 (17%) had intracerebral haemorrhage (ICH). Almost all the cases of PVH had developed by 4 days of age. Small-for-gestational age infants (12% of study population) had a significantly lower incidence and severity of PVH than appropriate-for-gestational age infants. Of 94 infants born between 23 and 28 weeks gestation, 45 (48%) had PVH. The PVH incidence was 60% in those of 23-26 weeks and 38% in those of 27-28 weeks. The hospital survival rate of ELBW infants was 69% in those without PVH and 43% in those with PVH; 70% in GLH alone; 50% in IVH and 14% in ICH. Three survivors developed post-haemorrhage hydrocephalus of whom two required ventriculoperitoneal shunting. Five survivors developed periventricular leukomalacia (PVL) evidenced by cysts identified between 3 and 7 weeks of age. A significant decrease in the incidence of PVH occurred over the study period (67% in 1982, 38% in 1983 and 33% in 1984). This decrease was seen for all grades of PVH. The reasons for this decreased incidence are still to be ascertained but this trend suggests that improvements in neonatal intensive care have the potential to improve the neurological outcome of more recent ELBW survivors.

Reduction in periventricular haemorrhage in preterm infants

Our previous cerebral ultrasound study of antecedents of periventricular haemorrhage in infants weighing 1250 g or less at birth suggested that neonatal events that caused increased or fluctuating cerebral blood flow lead to periventricular haemorrhage. As the risk period for this type of haemorrhage was the first four days of life strict guidelines were introduced to avoid the previously identified neonatal risk factors. No attempt was made to modify obstetric practice. Over the next two years, although the obstetric risk profile, the frequency and severity of hyaline membrane disease, and the gestation, birth weight, and sex distributions of a similar cohort of infants did not change, the incidence of periventricular haemorrhage decreased significantly from 60% to 36%. Significant antecedents of haemorrhage similar to those found in the previous study included severe bruising, low arterial:fractional inspiratory oxygen ratio and low packed cell volume on admission, hyaline membrane disease, hypercarbia, and hypoxaemia. Assisted ventilation, pneumothorax, treatment with tubocurarine, and hypotension were no longer significant risk factors for periventricular haemorrhage. A multivariate discriminant analysis correctly predicted haemorrhage in 86% of the study group when bruising, hypercarbia, hypoxaemia, hyaline membrane disease, and low gestation were considered. These results suggest that changes in neonatal practices can reduce the incidence of periventricular haemorrhage and that drug studies indicating similar reduction in haemorrhage need to be evaluated carefully to ensure that placebo and treated groups are in fact comparable.

Controversies in neonatal nutrition

The assessment of growth parameters remains one of the most practical and valuable tools to estimate nutritional status in neonates. Growth assessment in full-term infants is performed by using charts developed by the National Center for Health and Statistics. The assessment of post-natal growth in premature infants is controversial and can be performed by using either intrauterine or extrauterine standards. The selection of appropriate growth charts should be based on clinical, demographic, ethnic, and socioeconomic similarities of the population used for reference. Daily energy intakes ranging from 100 to 120 kcal/kg/day have been recommended for full-term infants, while higher intakes ranging from 114 to 181 kcal/kg/day have been recommended for premature neonates. Full-term infants should be nursed or nipple fed on demand; however, premature infants should ideally be tube fed by intermittent gastric feeding (gavage). Continuous gastric and transpyloric feedings are indicated in selected infants. Human milk is a preferred food for full-term infants during the first six months of life; however, this precept does not suggest that all infants who are exclusively breast-fed will grow adequately. Preterm human milk is also a preferred food for the low birthweight infant, provided nutritional supplements are used. It is unclear whether the supplementation of vitamin D, iron, and fluoride in full-term breast-fed infants should be started at birth, at the time of initiation of solid foods, or at the age of six months. The routine supplementation of multivitamins, folic acid, and vitamin E to all low birthweight infants is controversial. Most investigators suggest vitamin supplementation be given until the intake of formula or breast milk is sufficient to meet daily requirements. Vitamin E appears to exert a protective effect in premature infants against the development of severe retinopathy. The supplementation of vitamin E should be dependent upon the serum vitamin E concentration. It is controversial whether iron supplementation for premature infants should be initiated soon after birth or at two months of age, or whether higher doses of iron should be given to very low birthweight infants. If iron supplementation is started at birth, vitamin E status should be closely monitored. Although the optimal intakes of calcium and phosphorus in infant feedings have not been firmly established, the levels of calcium and phosphorus in human milk appear to be inadequate for the growing low birthweight infant.(ABSTRACT TRUNCATED AT 400 WORDS)