Pulse oximetry screening for critical congenital heart diseases at two different hospital settings in Thailand.

OBJECTIVE: To evaluate the predictive abilities of pulse oximetry screening (POS) for critical congenital heart disease (CRIT.CHD) at two different hospital settings in Thailand. STUDY DESIGN: The study was conducted in healthy newborns at Ramathibodi Hospital (RH), a university hospital and Maharat Nakhon Ratchasima Hospital (MH), a regional hospital. Positive POS was defined as oxygen saturation (SpO2) <95% or difference between pre- and postductal SpO2 >3%. RESULTS: Of 11 407 live births, 10 603 (92.9%) newborns were enrolled with a follow-up rate at 1 month of 78.3%. Incidence of CRIT.CHD (per 1000 live births) at RH and MH were 5.7 and 2.7, respectively. POS could detect three newborns who would have had a missed diagnosis. Sensitivity of POS for CRIT.CHD at RH was 82.3% vs 100% at MH. Overall specificity was 99.9% and false-positive rate was 0.009%. Combination of POS and physical examination (PE) enhanced detection ability to 100% at both hospitals. CONCLUSION: POS combined with PE improved detection of CRIT.CHD. Routine POS is useful in personnel-limited settings.

Echocardiographic parameters of patent ductus arteriosus in preterm infants.

OBJECTIVE: To analyze cardiovascular parameters by echocardiography in preterm infants with patent ductus arteriosus (PDA). SETTING: Tertiary-care pediatric university hospital. DESIGN: Cross-sectional, hospital-based study. PARTICIPANTS: 58 preterm infants, gestational age less than 33 weeks. MEASUREMENTS: A complete 2-dimension, M-mode, color doppler echocardiography was performed in each preterm infant at approximately 48 hours of life. RESULTS: Each preterm was categorized into hemodynamically significant PDA (hsPDA) (n=17, 29.3%), non-hemodynamically significant PDA (non-hsPDA) (n = 12, 20.7%), and no PDA (non-PDA) (n=29, 50%). Gestational age (29.4 ± 1.2 wk) and birth weight (1237 ± 358 g) of infants in hsPDA were significantly lower than those in non-PDA group (30.8 ± 1.3 wk, 1543 ± 361 g, P = 0.001), as compared to those in the non-hsPDA group (29.5 ± 2.3 wk, 1296 ± 462 g). Cardiovascular parameters including left atrium/aorta ratio, left atrium volume index, left ventricular dimensions and volumes, stroke volume, and cardiac output in hsPDA were significantly greater than those in non-hsPDA and nonPDA. LV systolic and diastolic functions were not significantly different in each group. LV global function in hsPDA (0.34 ± 0.13) was significantly lower than that in non-PDA (0.45 ± 0.13, P = 0.01). CONCLUSIONS: In preterm infants with hsPDA, there was a volume load of the left heart causing increased stroke volume and cardiac output. The hsPDA could be detected by echocardiography even in the first 48 hours. The left atrial volume index may be a better indicator of the volume load of the heart.

Vitamin A and E status in very low birth weight infants.

OBJECTIVE: To determine vitamin A and vitamin E status in very low birth weight (VLBW) infants at the time of birth (TB), at the time of full feeding (TFF) and at term postmenstrual age (TT). STUDY DESIGN: An observational study was conducted in VLBW infants. Plasma retinol and α-tocopherol levels were measured at TB, TFF and TT. Multivitamin supplementation was given to all infants to meet the daily requirement. RESULT: A total of 35 infants were enrolled. The median (interquartile range) of gestational age and birth weight was 30 (28 to 32) weeks and 1157 g (982 to 1406 g). The median of vitamin A and vitamin E intakes from TFF to TT was 832 and 5.5 IU kg(-1) day(-1), respectively. Vitamin A deficiency occurred in 67.7% at birth, 51.6% at TFF and 82.1% at TT. Vitamin E deficiency occurred in 77.4% at birth, 16.1% at TFF and 35.7% at TT. Small-for-gestational age was the only risk factor for vitamin A deficiency. Lower amount of breast milk consumption was associated with higher incidence of vitamin E deficiency. No differences in vitamin A- or vitamin E-related morbidities between infants with and without vitamin deficiencies were found. CONCLUSION: High prevalence of vitamin A and vitamin E deficiency was found in VLBW infants starting from birth to term postmenstrual age. Therefore, a higher dose of vitamin supplementation is required.

Oxygen saturation trends in preterm infants during the first 15 min after birth.

OBJECTIVE: To determine oxygen saturation (SpO(2)) trends in healthy preterm newborns during the first 15 min after birth and to ascertain factors affecting SpO(2) changes during that period. STUDY DESIGN: An observational study was conducted. Preterm newborns with gestational age (GA) less than 35 weeks, who did not require oxygen supplementation during the first 15 min of life, were enrolled. Pulse oximetry was applied to the right hand immediately after birth. SpO(2) data were recorded continuously every 2 s and were then transferred to a Microsoft Excel spreadsheet for analysis. The time to reach a stable SpO(2) >or=85 or >or=90% was described by the Kaplan-Meier method and compared using log-rank test. RESULT: A total of 102 preterm newborns were eligible, of whom 27 were excluded, resulting in 75 newborns enrolled into the study with a median (range) GA of 35 (29 to 35) weeks, median (range) birth weight of 2390 (1270 to 2990) g and median (range) Apgar scores at 1 and 5 min of 9 (5 to 10) and 10 (7 to 10), respectively. There was a gradual increase in SpO(2) with time. The median (interquartile range, IQR) SpO(2) at 2, 3, 4, 5 and 6 min was 77% (72 to 92), 84% (75 to 94), 88% (80 to 94), 90% (79 to 95) and 95% (85 to 97), respectively. Newborns with a lower GA seemed to have lower SpO(2) values. The median (IQR) time to reach a stable SpO(2) >or=85 or >or=90% was 4 (3 to 6) and 5 (3 to 57) min, respectively. The mode of delivery was a significant factor affecting SpO(2); infants delivered by cesarean section had a significantly lower SpO(2) and took a longer time to reach SpO(2) >or=85% compared with those delivered by vaginal delivery (HR=1.96, 95% CI=1.11 to 3.49; P=0.02). All enrolled newborns had no serious complications and they survived to discharge. CONCLUSION: SpO(2) in preterm newborns gradually increased with time. Approximately half of the preterm newborns had an SpO(2) <90% during the first 5 min of life. Infants delivered by cesarean section had a lower SpO(2) than those delivered by vaginal delivery.

N-terminal probrain natriuretic peptide and patent ductus arteriosus in preterm infants.

OBJECTIVE: To determine whether plasma N-terminal probrain natriuretic peptide (NT-proBNP) in premature infants could identify hemodynamically significant patent ductus arteriosus (HsPDA) and to determine the correlation between serial plasma NT-proBNP and echocardiographic assessment of ductal shunting. STUDY DESIGN: An observational study involving 35 preterm infants who underwent echocardiographic assessment for PDA on day 2, 4 and 7 of life with simultaneous blood sampling for determination of NT-proBNP concentrations. HsPDA was diagnosed by left-to-right ductal shunt on color Doppler, measuring diameter >1.5 mm on two-dimensional echocardiography plus > or =2 clinical features of PDA. RESULT: Plasma NT-proNBP levels on day 2 in the HsPDA group (n=12) were significantly higher than in non-HsPDA group (n=23) with a median of 16,353 pg ml(-1) (interquartile range (IQR), 12,360-33,459; range, 10,316-104,998) vs 3914 pg ml(-1) (IQR, 2601-5782; range, 1535-19,516) (P<0.001), respectively. Eight infants (67%) in the HsPDA group responded to an initial course of indomethacin or ibuprofen and their NT-proBNP levels significantly decreased within 48 h after treatment compared with non-responders (P=0.007). NT-proBNP concentrations were significantly correlated with left atrial to aortic root ratio. A cut-off NT-proBNP on day 2 of 10,180 pg ml(-1) offered the best predictive values for HsPDA with a sensitivity of 100% and a specificity of 91%. CONCLUSION: Plasma NT-proBNP on day 2 was found as a sensitive marker for predicting HsPDA in preterm infants. Successful closure of PDA was also correspondent with the decline in plasma NT-proBNP.

Neonatal infections in Asia.

OBJECTIVE: To study the epidemiology (including incidence, antibiotic sensitivity and mortality) of neonatal unit infections in countries in Asia. METHODS: One year prospective study of neonatal infections in eight neonatal units in Asia. RESULTS: There were 453 episodes of sepsis affecting 394 babies. Mortality from neonatal sepsis was 10.4%, with an incidence of 0.69 deaths/1000 live births. Group B streptococcus was the most common early-onset organism causing 38% of episodes of early-onset (<48 h old) sepsis, with a rate of 0.51 episodes per 1000 live births and a mortality of 22%. Gram-negative bacillary early-onset sepsis occurred at a rate of 0.15 episodes per 1000 live births with a mortality of 12%. There were 406 episodes of late-onset sepsis. The incidence was high at 11.6 per 1000 live births, and mortality was 8.9%. Coagulase-negative staphylococcus caused 34.1% of episodes, whereas Staphylococcus aureus caused only 5.4%. Gram-negative bacilli caused 189 episodes (46.6%). Only 44% of Gram-negative bacilli were sensitive to both gentamicin and a third-generation cephalosporin, whereas 30% were resistant to both antibiotics. Meningitis occurred in 17.2% of episodes of late sepsis, with a mortality of 20%. CONCLUSIONS: The incidence of late-onset sepsis was higher in Asia than in resource-rich countries, but the organisms isolated and mortality were similar. Over half of all Gram-negative bacilli were antibiotic resistant.

Cerebral blood flow velocity changes after bovine natural surfactant instillation.

OBJECTIVE: To determine the effects of bovine natural surfactant (beractant) instillation on cerebral hemodynamics in preterm infants with respiratory distress syndrome (RDS). STUDY DESIGN: Preterm infants who required surfactant for RDS were enrolled. Cerebral blood flow velocity (CBFV) waveforms from the pericallosal artery were analyzed by pulsed Doppler ultrasonography with the anterior fontanel serving as an acoustic window. CBFV was measured before and at 5, 10, 20, and 30 minutes after the first dose of a bolus instillation of surfactant in four aliquots. Simultaneously with CBFV measurements, mean blood pressure (MBP), heart rate, and ventilator settings were recorded. pH, PACO2, and PAO2 before and at 30 minutes after surfactant administration were also determined. RESULTS: The 30 enrolled preterm infants had a mean birth weight of 973 gm (513 to 1996 gm) and a mean gestational age of 27 weeks (23 to 33 weeks). Mean postnatal age at surfactant administration was 4.7 +/- 2.7 hours. There were no significant changes in pH and PACO2 before and at 30 minutes after surfactant (before surfactant: mean pH of 7.29 +/- 0.07 and mean PACO2 of 44.4 +/- 7.1 torr; after surfactant: mean pH of 7.31 +/- 0.07 and mean PACO2 of 42.7 +/- 8.3 torr). PAO2 increased significantly from a pre-surfactant mean of 83 torr to 130 torr at 30 minutes after surfactant (p < 0.05), with no significant changes in mean airway pressure. There were no significant changes in MBP, heart rate, mean CBFV, peak systolic flow velocity, and diastolic flow velocity before and after surfactant instillation regardless of gestational age. Individual changes in mean CBFV were related to MBP changes (p < 0.001, linear mixed models with random effects). CONCLUSION: In low birth weight infants with RDS, bovine surfactant instillation is not associated with a significant alteration in cerebral hemodynamics. However, the direct relationship between CBFV and MBP is consistent with the reported pressure-passive cerebral circulation in sick preterm infants.

Blood pressure measurements in the newborn.

This article reviews the methods of blood pressure measurements, values reported on premature and term infants, and the significant changes in trends and measurements reported with various conditions. Understanding the underlying mechanisms or conditions that may be associated with blood pressure derangements enable the clinician to determine appropriate treatment and optimal monitoring of responses to instituted therapy.