Anna Petrova

Near-infrared spectroscopy in the detection of regional tissue oxygenation during hypoxic events in preterm infants undergoing critical care.

Objectives: To determine whether pulse oximetry-detected episodes of desaturation are associated with impairment of cerebral and somatic (renal) tissue oxygenation in mechanically ventilated preterm neonates. Design: Observational cross-sectional study. Setting: Neonatal intensive care unit of a university-affiliated childrens hospital. Patients: Ten mechanically ventilated preterm (gestational age 24–32 wks) infants. Interventions: In addition to the traditional monitoring of hemodynamic variables that included pulse oximetry (Sao2), near-infrared spectroscopy (NIRS) was used to evaluate the cerebral and somatic (renal) tissue oxygen saturation (rSO2C and rSO2R, respectively). Measurements and Main Results: A total of 40 rSO2C and rSO2R measurements were simultaneously recorded: 20 during hypoxic events when the Sao2 was ≤80% for ≥4 secs (cases) and generally ranged between 70% and 80%, and 20 measurements when the Sao2 was ≥85% (paired controls). Additionally, the fractional oxygen extraction (FOE) from the cerebral (FOEC) and renal (FOER) tissue was calculated. All the measurements were made under steady conditions during a 2-hr period. The rSO2C, rSO2R, FOEC, and FOER among the cases (Sao2 ≤ 80%) and controls (Sao2 ≥ 85%) were compared using the paired Students t-test. Both rSO2C and rSO2R during the desaturation episodes were lower than in the controls (51.6 ± 6.3% vs. 66.2 ± 10.2%, p < .0001 and 61.1 ± 6.8% vs. 80.1 ± 10.0%, p < .0001, respectively). The FOEC during the hypoxic episodes was comparable with control levels but increased in renal tissue. However, during two of the desaturation episodes (10%), the rSO2C and FOEC levels (which were <44% and >0.47, respectively) may reflect compromised tissue oxygen supply. Conclusions: In the majority of mechanically ventilated preterm neonates, the reduction in cerebral and renal tissue oxygenation associated with short periods of decreased arterial saturation to 70–80% does not significantly compromise oxygen utilization in the cerebral tissue but increases oxygen extraction in the renal tissue, which might cause ischemic tissue injury following a further reduction in oxygen delivery.

Effect of storage on breast milk antioxidant activity

Background: Human milk, which contains compounds beneficial to infants, is often expressed and stored before use. Changes in its antioxidant activity with storage have not been studied. Objectives: To measure antioxidant activity of fresh, refrigerated (4°C), and frozen human milk (−20°C), stored for two to seven days; to compare the antioxidant activity of milk from mothers delivering prematurely and at term; to compare the antioxidant activity of infant formulas and human milk. Methods: Sixteen breast milk samples (term and preterm) were collected from mothers within 24 hours of delivery and divided into aliquots. Fresh samples were immediately tested for antioxidant activity, and the rest of the aliquots were stored at −20°C or 4°C to be analysed at 48 hours and seven days respectively. The assay used measures the ability of milk samples to inhibit the oxidation of 2,2′-azino-di-3-(ethylbenzthiazolinesulphonate) to its radical cation compared with Trolox. Results: Antioxidant activity at both refrigeration and freezing temperatures was significantly decreased. Freezing resulted in a greater decrease than refrigeration, and storage for seven days resulted in lower antioxidant activity than storage for 48 hours. There was no difference in milk from mothers who delivered prematurely or at term. Significantly lower antioxidant activity was noted in formula milk than in fresh human milk. Conclusions: To preserve the antioxidant activity of human milk, storage time should be limited to 48 hours. Refrigeration is better than freezing and thawing.

Biologically active breast milk proteins in association with very preterm delivery and stage of lactation.

Objective:The aim of this study was to identify the independent effect of very preterm gestation on breast milk content of biologically active proteins (secretory immunoglobulin A (sIgA), lysozyme, lactoferrin, osteoprotegerin (OPG), leptin, adiponectin and β-endorphin (b-EP)) during the first month of lactation.Study Design:We collected samples of transitional (6 to 8 and 13 to 15 days) and mature (20 to 22 and 27 to 29 days) milk from mothers after term (38 to 41 weeks) or very preterm (24 to 31 weeks) delivery. The levels of sIgA, lysozyme, lactoferrin, OPG, leptin, adiponectin and b-EP in the breast milk were quantified using enzyme-linked immunosorbent assay or enzyme immunoassay kits. Statistical analysis included descriptive statistics and regression analysis.Result:Sixty breast milk samples were collected from 15 mothers after very preterm (preterm breast milk, PBM) and 20 samples from 5 mothers after term (term breast milk, TBM) deliveries. Decrease in lysozyme, lactoferrin, OPG, leptin, adiponectin and b-EP but no change in sIgA was recorded during the first month of lactation in both TBM and PBM. The IgA, lysozyme and adiponectin were higher in PBM than in TBM, whereas concentrations of lactoferrin, OPG and leptin were higher in TBM than in PBM (P<0.05 to 0.0001). A similar pattern was seen in the lysozyme, leptin and adiponectin concentration in mature milk. Increased b-EP levels in breast milk were associated with the vaginal mode of delivery but not gestational age.Conclusion:Although a similar pattern of change was observed in the breast milk bioactive proteins during the first month of lactation after term and very preterm gestation, PBM is a better source of factors with antibacterial/anti-inflammatory activities but is constantly deficient in leptin, which is involved in neuroendocrine regulation.

Neonatal morbidity and placental pathology.

Objective: To investigate the association between gestational age, placental pathology and outcome among preterm births.Methods: Medical records and placental pathology results of 165 preterm infants (gestational age ≤34 weeks) were used to analyze the development of intraventricular hemorrhage (IVH), bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), patent ductus arteriosus (PDA) and sepsis, in association with placental findings in the gestational age categories of 22–27 (n=71) and 28–33 (n=93) weeks.Results: Significant differences were found in placental findings based on gestational age and neonatal morbidity. Lower gestational age was associated with increased infection-related lesions such as chorionic vasculitis (47.9%, P<0.001) and acute chorioamnionitis (67.6%, P<0.001). Placental lesions reflecting disturbances of fetal-placental blood flow (infarction, chorionic plate thrombi and basal perivillous fibrin) were predominantly seen in the 28–33 week gestational age category (P<0.05–0.01). Despite the high prevalence of chorioamnionitis (38.8%), no significant association was found between this lesion and the tested preterm morbidity after controlling for gestational age. Only, villous edema and chorionic vasculitis were identified as independent predictors for the development of IVH (49.2%, ORA 2.57, 95% CI 1.01, 6.58 and 39.3%, ORA 1.95, 95% CI 1.01, 4.21, respectively).Conclusion: Villous edema and chorionic vasculitis are significant risk factors for the development of the IVH among neonates born at gestational age ≤34 weeks.

Regional tissue oxygenation in preterm born infants in association with echocardiographically significant patent ductus arteriosus

Objective:To analyze the levels of regional tissue oxygenation in preterm infants in association with echocardiographically significant patent ductus arteriosis (PDA).Study Design:Preterm infants with gestational age less than 32 week were enrolled before the first dose of the pharmacological treatment for the PDA. Non-invasive near-infrared spectroscopy (NIRS) technology was utilized to measure cerebral (rSO2-C), renal (rSO2-R) and mesenteric (rSO2-M) tissue oxygenation for approximately 60 min. Regional fractional oxygen extraction (FOE) was calculated using simultaneously measured arterial saturation (SaO2). We analyzed regional tissue oxygenation and oxygen extraction, hemodynamic parameters, and demographic and clinical information in association with the size of the PDA (moderate vs large).Result:Among the 38 enrolled infants, the majority were diagnosed with a large (63.2%, n=24) and the rest with a moderate-sized PDA. Infants with large and moderate PDA were comparable in terms of gestational age, study age and weight, mode of delivery and hemodynamic parameters. A significantly higher proportion of infants with a moderate PDA were mechanically ventilated as compared with those with a large PDA. We found no significant differences in the rSO2-C and rSO2-R, irrespective of the type of respiratory support. However, in infants with a large PDA on continuous nasal positive airway pressure (NCPAP), the rSO2-M was lower and mesenteric FOE was higher than that in mechanically ventilated neonates with a large PDA, and in those with moderate PDA irrespective of the type of respiratory support.Conclusion:The PDA size did not affect cerebral and renal tissue oxygenation, but the mesenteric tissue oxygenation was decreased in infants with a large PDA on NCPAP.

Impact of Race and Ethnicity on the Outcome of Preterm Infants Below 32 Weeks Gestation

OBJECTIVES: To determine the impact of race/ethnicity on mortality and morbidity such as intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), bronchopulmonary dysplasia (BPD) and bacteriologically confirmed sepsis, assisted ventilation, surfactant administration, intrauterine growth retardation (IUGR), and patent ductus arteriosus (PDA) among very prematurely delivered infants.STUDY DESIGN: Retrospective study of a cohort of 1006 preterm neonates with gestational age ranging from 22 to 32 weeks discharged from the Neonatal Intensive Care Unit (NICU) between 1998 and 2001. Subgroup analysis according to gestational age (GA) (22 to 24, 25 to 28, and 29 to 32 weeks) and plurality (singleton and multiple) was performed using the χ 2 test and an analysis of variance.RESULTS: Of the 1006 infants, 54.3% were white, 21.7% black, 13.7% Hispanic, and 10.3% were classified as Other. Multiple births among white infants were approximately twice that in (42.4%) black infants (22.1%), and was also significantly higher than in the Hispanic (28.3%) and other race/ethnic groups (25.2%). Overall, a higher proportion of black infants were born with a GA ≤28 weeks (n=115, 55.3%) than white (n=201, 37.1%) and Hispanic (n=53, 38.4%), p<0.05. Therefore, black neonates had a lower GA (27.9±2.9 weeks) and birth weight (1170±463 g) as compared to white (p<0.0002) and Hispanic infants (p<0.0001). There was no significant impact of race/ethnicity on the mean gestational age in any of the gestational age categories. Infant mortality and morbidity in each gestational age category by race/ethnicity were comparable. The multiple birth black infants were seen to have a lower gestational age and birth weight as compared to singleton black as well as to white, Hispanic and other race/ethnic groups. However, this did not influence morbidity and mortality in multiple birth black neonates. The result of this study showed that the level of prematurity and not plurality predominantly influences the rate of infant mortality and morbidity in each race/ethnic category.CONCLUSIONS:The reduction in gestational age and birth weight in black neonates is not associated with an increased risk of infant mortality and morbidity. In general, the outcomes of black singleton and multiple pregnancies were comparable with those of white, Hispanic and other race/ethnic groups.

The accuracy of transcutaneous bilirubin measurements in neonates: A correlation study

A prospective observational study was conducted on 212 neonates born between 24 and 42 weeks of gestation who required blood sampling to determine total serum bilirubin (TSB) in the first week of life, prior to phototherapy. The transcutaneous bilirubin (TcB) measurements were performed on the infant’s forehead using BiliCheck™ within ±30 min of a blood sample being drawn. There was significant (r = 0.78) correlation between bilirubin levels obtained transcutaneously and those measured in the infant’s blood. The correlation was not affected by birth weight and was dependent on the bilirubin levels. The negative nonsignificant correlation appears when TSB levels are greater than 11 mg/dl. Thus, TcB measurements can accurately predict TSB values lower than 11 mg/dl in a multiracial preterm and term neonatal population.

Vitamin D in the maternal-fetal-neonatal interface: clinical implications and requirements for supplementation.

Abstract Identification of the current evidence regarding the pathophysiological and clinical facets of vitamin D in the maternal–fetal–neonatal interface is of value because of the significance of the vitamin D endocrine system in human health and high prevalence of vitamin D deficiency in mothers and their infants. Although many questions have still not been answered by the existing literature, we found evidence that: (i) during pregnancy vitamin D participates in fetal skeletal mineralization and growth, (ii) neonatal vitamin D levels are dependent on the maternal vitamin D status at delivery, (iii) a vitamin D sufficient status at birth may decrease the risk for the development of asthma and type 1 diabetes mellitus in later life, (iv) recommendations for maintaining serum 25-hydroxyvitamin D [25(OH)D] levels ≥32 ng/mL to avoid secondary hyperparathyroidism in adults have not been applied to mothers and their infants, (v) American Academy of Pediatrics recommended supplementation of 400 IU of vitamin D per day is sufficient only for infants who are born with normal vitamin D levels and (vii) supplementation of lactating mothers with high doses of vitamin D (4000 IU/d) allows the achievement of optimal 25(OH)D concentrations (>32 ng/mL) in the maternal and infant serum without any risk of hypervitaminosis D in the mother. We believe that inconsistency in the recognition of sufficient levels of vitamin D in mothers and their infants affects the identification of adequate doses for vitamin D supplementation during pregnancy, lactation and infancy.

Risk of cardio-respiratory abnormalities in preterm infants placed in car seats: a cross-sectional study

BackgroundLittle is known about the factors that predispose to the occurrence and severity of cardio-respiratory symptoms during the placement of a prematurely born infant in a car seat. The impact of gestational age, weight at discharge and infants pre-existing cardio-respiratory status (in the supine position) on cardio-respiratory function during pre-discharge testing in a car seat (semi-upright position) has not been investigated.MethodsThe cardio-respiratory function of 42 preterm neonates with gestational age 24 to 35 weeks and discharge weight 1790 to 2570 grams were monitored for 45 minutes before, during, and after placement in a car seat. The occurrence of periodic breathing, apnea, bradycardia, or decreased oxygen saturation (SaO2) was analyzed.ResultsPrior to the car seat testing, 15 (35.7%) infants displayed one or more abnormalities of cardio-respiratory function. During the car seat testing, 25 (59.6%) infants had periodic breathing, 33 (78.2%) had oxygen saturation <90%, 14 (33.3%) had bradycardia less than 80 beats per minute, and 35 (83.3%) had a combination of these symptoms. Infants, both with and without pre-existing cardio-respiratory abnormalities, had an almost equal probability (80% vs. 83.3%) for the development of cardio-respiratory symptoms during placement in the car seat. Weight at discharge ([less than or equal to] 2,000 grams) but not the gestational age (<28 weeks or [greater than or equal to] 28<37 weeks), was associated with either increased episodes of oxygen desaturation or the combination of cardio-respiratory symptoms that were seen during the placement of these infants in the car seat. Repositioning from the car seat to the supine position showed normalization of cardio-respiratory function in the majority (83%) of the tested infants. None of the tested clinical factors were associated with the severity of the cardio-respiratory symptoms.ConclusionPre-discharge testing of the cardio-respiratory function of preterm infants during placement in a car seat is important for the prevention of cardio-respiratory symptoms during their transportation. However, the high risk for developing cardio-respiratory symptoms will require the consideration of an alternative mode of safe home transportation for preterm infants; especially those with a discharge weight less than 2,000 grams.

Health Care Practices of the Foreign Born Asian Indians in the United States. A Community Based Survey

Although successful utilization of medical and preventive care by members of the non-US born communities is an important public health concern, our knowledge regarding health practices of different ethnic subgroups is limited. In the present study, participants of the health fairs organized during South Asian cultural and religions events were asked anonymously to complete the South Asian Total Health Initiative (SATHI) health survey questionnaire to evaluate their health-related practices, self-health perception, and satisfaction with medical care. Among 1,250 surveyed, 1,016 foreign born Asian Indians adults that represented the fastest growing subgroups of the South Asian born nationals in the US were included in the analysis. We found that the majority reported healthy behavior (exercise activities and abstinence from alcohol or tobacco), high self-health perception, satisfaction with medical care, and compliance with annual routine medical examinations that was directly associated with the annual house income. Approximately 40% of women complied with breast and cervical cancer screenings and less than 20% of men complied with prostate cancer screening guidelines. Presence of chronic conditions (mostly cardiovascular pathology and/or diabetes) that were reported by approximately half of the participants negatively impacted their self-health perception. In conclusion, positive self-reported health perception and compliance with routine health examinations of the surveyed foreign born Asian Indians was reported along with an increased rate of chronic morbidity and underutilization of specific preventive services. Observed discrepancy between self-health perception and health status highlights the need to enhance utilization of preventive services among the non-US born Asian Indian community.