Boris Metze

B-Type Natriuretic Peptide to Predict Ductus Intervention in Infants <28 Weeks

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

Accelerated lung maturation following maternal steroid treatment in infants born before 30 weeks gestation

A meta-analysis was performed of 9 controlled trials of maternal beta-/dexamethasone treatment in which the incidence of RDS in infants born before 30 weeks gestation was reported. A significant decrease could be shown in 250 immature infants. The number of cases was to small for analysis of lower gestational ages or for the demonstration of a reduction in mortality. In a separate study of 135 infants born before 30 weeks gestation tracheal aspirate phospholipid analysis was performed using thin layer chromatography. 64 of them had been exposed prenatally to steroids. Significantly more of these infants had a mature L/S ratio > or = 2.7 (p < 0.02) and prenatal glucocorticoid treatment was associated with a markedly increased survival rate (odds ratio 2.4, p < 0.02). We conclude from the meta-analysis of the literature and from the findings of our study, that accelerated lung maturation follows prenatal steroid treatment with a reduction in RDS-incidence even in very immature fetuses. Consequently it would be appropriate to administer glucocorticoids combined with tocolysis since this has been shown to be beneficial for those women threatening to deliver prematurely at less than 30 weeks gestation.

Thrombocytopenia in the First 24 Hours After Birth and Incidence of Patent Ductus Arteriosus

BACKGROUND: Experimental studies suggest that platelet-triggered ductal sealing is critically involved in definite ductus arteriosus closure. Whether thrombocytopenia contributes to persistently patent ductus arteriosus (PDA) in humans is controversial. This was a retrospective study of 1350 very low birth weight (VLBW; <1500 g) infants, including 592 extremely low birth weight (ELBW; <1000 g) infants. METHODS: All infants who had a platelet count in the first 24 hours after birth and an echocardiogram performed on day of life 4 to 5 were included. The incidence of thrombocytopenia was analyzed in infants with and without PDA, and in those who did or did not undergo PDA intervention. The impact of thrombocytopenia, gestational age, birth weight, gender, and sepsis on PDA was determined by receiver operating characteristic curve, odds ratio, and regression analyses. RESULTS: Platelet numbers within the first 24 hours after birth did not differ between VLBW/ELBW infants with and without spontaneous ductal closure. Platelet numbers were not associated with subsequent PDA treatment. Low platelet counts were not related to failure of pharma-cologic PDA treatment and the need for subsequent surgical ligation. Lower gestational age or birth weight, male gender, and sepsis were linked to the presence of PDA in VLBW infants on day of life 4 to 5. CONCLUSIONS: Thrombocytopenia in the first 24 hours after birth was not associated with PDA in this largest VLBW/ELBW infant cohort studied to date. Impaired platelet function, due to immaturity and critical illness, rather than platelet number, might play a role in ductus arteriosus patency.

Comparison of left ventricular cardiac dimensions between small and appropriate for gestational age preterm infants below 30 weeks of gestation

Abstract Objective: The development of the left cardiac structures in the early life of small for gestational age (SGA) preterm infants has been inadequately studied. The aim of the study was to compare the left ventricular cardiac dimensions between SGA and appropriate for gestational age (AGA) preterm infants. Methods: Echocardiography was performed on day 2 (T1) and at age 1 month (T2) in 19 SGA preterm infants (birthweight <3rd percentile) and 21 AGA controls (P25-50) matched for gestational age (<30 weeks). Results: The left ventricular cardiac dimensions did not differ significantly between SGA and AGA infants at either T1 or T2 after correction for body length. The left ventricular mass was similar for SGA and AGA infants at T1 and T2 after correction for body weight or body length. The left ventricular output increased significantly from T1 to T2 in both SGA and AGA infants [SGA: 350 (T1)–640 (T2) mL/kg/min, P<0.05; AGA: 300 (T1)–510 (T2) mL/kg/min, P<0.05]. Conclusions: The left cardiac structures related to body length are comparable between SGA and AGA preterm infants in the first month of life and show similar development.

Diminished cord blood lymphocytel-selectin expression in neonatal bacterial infection

Abstractl-Selectin, a leukocyte surface glycoprotein involved in white blood cell extravasation, is rapidly down-regulated after leukocyte activation. We prospectively determined lymphocytel-selectin expression in freshly obtained cord blood samples of 98 neonates (gestational age 25–42 weeks). In eight infants with bacterial infection, the mean percentage ofl-selectinhigh lymphocytes was 32.5% (SD 20.1%), compared to 60.1% (SD 18.7%) in the control group (P<0.01). A percentage ofl-selectinhigh lymphocytes of less than 42% had a sensitivity of 75% and a specificity of 82% in identifying infected newborns. Cord blood lymphocytel-selectin expression was independent of gestational age, birth weight, umbilical artery pH, hematocrit, white blood cell count, absolute neutrophil count, C-reactive protein level, or maternal fever before delivery while there was a weak correlation with the newborns immature/total ratio and platelet count. To our knowledge, this is the first report demonstrating downregulation of human lymphocytel-selectin expression following activation of the immune system in vivo.

Birth weight-related percentiles of brain ventricular system as a tool for assessment of posthemorrhagic hydrocephalus and ventricular enlargement.

Abstract Besides remarkable improvements of neonatal medical therapy, neurological morbidity remains a major concern in preterm infants. In particular, intracranial hemorrhage is a severe complication strongly correlated to poor neurological outcome. For early clinical assessment of intracranial hemorrhage and its impact on the ventricular system, cranial sonography is an important bedside diagnostic tool. Reference values of ventricular sizes are available in relation to gestational age (GA). So far, it has not been demonstrated that ventricular size values are also reliable in relation to birth weight (BW). In this study, we performed cranial ultrasonography in 250 preterm and term newborn infants. Measurements of the intracranial ventricular system by cranial ultrasound examination were performed within 72 h after birth. We determined ventricular index, anterior horn width, width of the third ventricle, width and length of the fourth ventricle for statistical analysis in relation to BW and GA. GA ranged from 23 weeks, 3 days to 42 weeks, 1 day (mean: 33 weeks), BW ranged from 345 to 5620 g (mean: 2146 g). Ventricular index and fourth ventricle width revealed a significant correlation to birth weight with r=0.75, each. A significant correlation to birth weight was also obtained for width and length of the third ventricle (r=0.55 and 0.47, respectively). Correlations obtained for ventricular measures in relation to GA were similar to those referring to BW. In preterm and term infants, ventricular sizes in relation to BW seem reliable for assessment and monitoring of ventricular pathologies, i.e. after intracranial hemorrhage.

Association between Platelet Counts before and during Pharmacological Therapy for Patent Ductus Arteriosus and Treatment Failure in Preterm Infants

Background The role of platelets for mediating closure of the ductus arteriosus in human preterm infants is controversial. Especially, the effect of low platelet counts on pharmacological treatment failure is still unclear. Methods In this retrospective study of 471 preterm infants [<1,500 g birth weight (BW)], who were treated for a patent ductus arteriosus (PDA) with indomethacin or ibuprofen, we investigated whether platelet counts before or during pharmacological treatment had an impact on the successful closure of a hemodynamically significant PDA. The effects of other factors, such as sepsis, preeclampsia, gestational age, BW, and gender, were also evaluated. Results Platelet counts before initiation of pharmacological PDA treatment did not differ between infants with later treatment success or failure. However, we found significant associations between low platelet counts during pharmacological PDA therapy and treatment failure (p < 0.05). Receiver operating characteristic (ROC) curve analysis showed that platelet counts after the first, and before and after the second cyclooxygenase inhibitor (COXI) cycle were significantly associated with treatment failure (area under the curve of >0.6). However, ROC curve analysis did not reveal a specific platelet cutoff-value that could predict PDA treatment failure. Multivariate logistic regression analysis showed that lower platelet counts, a lower BW, and preeclampsia were independently associated with COXI treatment failure. Conclusion We provide further evidence for an association between low platelet counts during pharmacological therapy for symptomatic PDA and treatment failure, while platelet counts before initiation of therapy did not affect treatment outcome.