Accuracy of mortality rates for livebirths 500-999 g birthweight.
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Humans↗
Biomedical subjects
V Y Yu
Publications and source records attributed to V Y Yu.
Improving health status in extremely low birthweight children between two and five years.
The 5-year outcome of 101 extremely low birthweight (ELBW, < 1000 g) children discharged from the Neonatal Intensive Care Unit was reported. Over this period, there were four post-discharge deaths. The neurodevelopmental impairment rate was 18% overall: cerebral palsy 7%, blindness 3%, deafness 3% and developmental delay 10%. Seventy-one percent of children were readmitted to hospital. The mean number of admissions was 2.4 per child and the mean duration of total hospital stay was 11.3 days per child in the 5-year period. A trend was observed in a reduction in the readmission rate and hospital days in the 2-5-year period compared to the period between discharge and 2 years, though the differences were not statistically significant. The most common reason for readmission was for surgical procedures, primarily aural ventilation tube insertion and tonsillectomy and adenoidectomy. Significant health problems included recurrent wheezing episodes, stridor and croup in the period up to 2 years and otitis media and tonsillitis between 2 and 5 years. There was some catch-up growth, especially in height, between 2 and 5 years. Children with < 800 g birthweight had similar rates of neurodevelopmental impairment and hospital readmission to those of 800-999 g birthweight. However, they experienced more otitis media and pneumonia, had more ear, nose and throat operations, and at 5 years of age, more were below the 3rd centile for weight. This study showed that the health status of ELBW children had improved between 2 and 5 years, but they continued to experience recurrent health problems and hospital readmissions which would have resulted in added financial and emotional burdens to their families.
Child Development↗
Survival prospects of extremely preterm infants: a 10-year experience in a single perinatal center.
During a 10-year period, 1977 to 1986, 233 (53%) of 442 inborn live births between 23 and 28 weeks' gestation survived; their 1-year survival rate was 7% at 23 weeks, 30% at 24 weeks, 31% at 25 weeks, 55% at 26 weeks, 67% at 27 weeks, and 71% at 28 weeks. No significant change in survival rate was observed over the years. Twelve percent of pregnancies and 20% of infants were multiple gestations. Singleton births had significantly higher survival rates compared with multiple births (58% versus 41%). The obstetric intervention rate, as measured by the frequency of cesarean section, increased significantly over the years: from 15% in 1977-1978 to 33% in 1985-1986. The neonatal intervention rate, as measured by the frequency of live births offered neonatal intensive care, remained unchanged. Ten percent were not treated: 4% had major malformations and 6% were considered "nonviable." Active perinatal management, which assumed fetal-neonatal viability, accounted for better survival rates compared with centers with a more passive management policy. Information on survival based on gestational cohorts plays an important role in helping obstetricians, neonatologists, and parents make appropriate management decisions.
Cesarean Section↗
Effect of fetal haemoglobin on the accuracy of pulse oximetry in preterm infants.
Pulse oximeters are programmed with a calibration curve derived from studies done in adults. Whether fetal haemoglobin levels affect their reliability is unclear. This study reports the accuracy of pulse oximetry in 22 preterm infants (mean 31 weeks, range 25-36 weeks gestation) between 1 h and 73 days of age. Oxygen saturation obtained from a Nellcor N-200 pulse oximeter (SpO2) was compared with simultaneous arterial values (functional SaO2) measured by a Radiometer OSM3 Hemoximeter over a SpO2 range of 83-99%. Fetal haemoglobin (HbF), carboxyhaemoglobin (HbCO) and methaemoglobin (HbMet) measured by the hemoximeter ranged between 0-100%, 0-3.5% and 0-0.8% respectively. Linear regression analysis revealed a close correlation between SpO2 and functional SaO2 (SpO2 = 0.75 SaO2 + 24.43, r = 0.88, P less than 0.001) over a wide range of values for PCV, heart rate, blood pressure, PaO2, PaCO2 and pH. The mean SpO2-SaO2 difference of 1.3, (s.d. 2.5%, P less than 0.001) was unaffected by HgF, HbCO or HbMet but was increased in infants receiving inotropic support. We conclude that the Nellcor N-200 pulse oximeter gives reliable oxygen saturation measurements unaffected by the HbF level in preterm infants.
Fetal Hemoglobin↗
Simultaneous measurement of preductal and postductal oxygen saturation by pulse oximetry in hyaline membrane disease.
Preductal and postductal oxygen saturation were compared in 20 ventilated preterm infants with hyaline membrane disease to establish the frequency of right to left shunting and to assess the accuracy of postductus arteriosus blood gas sampling. One hundred and thirty eight comparisons were made and the frequency of right to left shunting was 17% (95% confidence interval 12 to 25%). Shunting episodes with possible preductal hyperoxia occurred far less commonly on a maximum of 5% of occasions. The findings in infants under 1000 g and of 24-28 weeks' gestation were not significantly different from larger or more mature infants. Shunting occurred significantly more frequently in very ill infants who subsequently died as a result of respiratory disease.
Ductus Arteriosus, Patent↗
Neonatal consequences of placental and membrane dysfunction.
Early amnion rupture is a sporadic event that results in mechanical teratogenesis due to amniotic-band disruption and/or compression. It may cause abortion or stillbirth, craniofacial clefts, and cerebral, body wall and limb/skeletal defects. Prolonged and premature rupture of membranes and oligohydramnios result in the dry-lung syndrome and pulmonary hypoplasia. The risk of chorioamnionitis is also increased, with serious consequences to the fetus and neonate. Placental lesions are associated with fetal growth retardation, preterm birth, fetal malformations and other neonatal disorders (congenital infections, erythroblastosis, alpha thalassaemia). In particular, the impact of extremely preterm births on perinatal mortality rates and health costs is substantial. The 1-year survival rate of singleton infants born at the Monash Medical Centre was 10% at a gestation period of 23 weeks, 37% at 24 weeks, 42% at 25 weeks, 61% at 26 weeks and 78% at 27 weeks (11% at birthweights of 500-599 g, 30% at 600-699 g, 55% at 700-799 g and 71% at 800-899 g). Proven measures to minimize the neonatal consequences of extremely preterm delivery include in utero transfer of at-risk fetuses to a perinatal centre and antepartum corticosteroids. Research into the pathophysiological basis of placental and membrane dysfunction may help reduce the prematurity rate.
Adrenal Cortex Hormones↗
Duration of hospitalization in extremely preterm infants.
This study reports the age at hospital discharge of 233 survivors and age at death of 209 infants who were born at 23-28 weeks gestation over a 10 year period, 1977-86. The mean duration of hospitalization of survivors was 95 days and was inversely related to maturity at birth; those born at 23-25 weeks remained in hospital on average 1-2 weeks beyond term while those born at 26-28 weeks went home on average at term or 1 week before term. The mean age at death was 12 days: 53% within 1 day, 23% between 2 and 7 days, 15% between 8 and 28 days and 9% between 28 days and 1 year. The proportions of death in the post-neonatal period for infants born at 23-24 weeks, 25-26 weeks and 27-28 weeks were 2, 9 and 16% respectively. There was no significant trend in prolonged hospitalization of survivors or postponement of neonatal deaths to the post-neonatal period over the 1977-86 period. Nevertheless, both neonatal and post-neonatal mortality should continually be monitored in this extremely preterm group.
Gestational Age↗
Intravenous indomethacin therapy in preterm neonates with patent ductus arteriosus.
This study examined the response of the patent ductus arteriosus (PDA) to intravenous Indomethacin using serial two dimensional and Doppler echocardiography and documented the complications associated with therapy. Thirty-six preterm neonates who were oxygen and ventilator dependent were studied when they were aged 3-7 days. The PDA initially closed in 22 (61%) and constricted in seven (19%) of the infants. It was non-responsive in five (14%) and the treatment was stopped because of complications in two (6%). Only three (43%) of seven neonates given a second course had PDA closure. In the 25 instances where there was PDA closure following Indomethacin, re-opening was documented echocardiographically on three (12%) occasions. Overall, Indomethacin therapy was successful in 29 (81%) neonates, PDA ligation was required in four (11%) and three died from unrelated causes. Three (8%) neonates developed major complications: multiple gastric perforations in the first, focal ileal perforation in the second, and necrotizing enterocolitis in the third. Treatment failure, PDA ligation and major complications occurred exclusively in neonates less than 28 weeks gestation. In view of the relatively low efficacy and high major complication rate in these extremely preterm infants, a randomized clinical trial needs to be conducted using two dimensional and Doppler echocardiography to allow accurate assessment of the PDA response to intravenous Indomethacin.
Ductus Arteriosus, Patent↗
Methods of delivery and resuscitation of very-low-birthweight infants in Victoria: 1982-1985.
This article describes the patterns of delivery and resuscitation for very-low-birthweight infants who were born in Victoria from 1982 to 1985. Caesarean delivery rates increased from 15% to 30% for infants of birthweights of 500-999 g, and from 39% to 52% for infants of birthweights of 1000-1499 g. In level-III hospitals, the proportion of live-born infants who did not receive active resuscitation fell from 32% to 18% for those who weighed 500-999 g, and from 28% to 15% for those who weighed 1000-1499 g. Time trends over the four years showed the management of very-low-birthweight infants to be in a state of rapid transition in all birth settings. At the same time there was a fall in the still-birth rate of infants of birthweights of 500-999 g. Still-births rates for infants of birthweights of 1000-1499 g remained unchanged, as did neonatal mortality rates in both weight groups.
Apgar Score↗
Neonatal sepsis and infection control policies in Australia.
The pattern of neonatal bacterial infection, its management and the types of infection control policy were ascertained in 20 neonatal intensive care units (NICU) in Australia by questionnaire survey. Group B Streptococcus and Escherichia coli were the predominant organisms responsible for perinatally acquired infection for which the most common antibiotic combination used was Penicillin and Gentamicin. Staphylococcus epidermidis and aureus (majority Methicillin resistant) were the predominant organisms responsible for nosocomial infection for which the most common antibiotic combination used was Vancomycin and Cefotaxime. A Serratia epidemic was experienced in four NICU. Lumbar and suprapubic punctures were frequently done as part of the diagnostic workup in nosocomial infections but not with perinatally acquired infections. Haematological indices considered useful as a diagnosis aid varied between NICU and acute phase reactants were rarely relied upon for diagnosis or for monitoring treatment response. Granulocyte transfusion and intravenous immunoglobulins were infrequently used in therapy. No consensus was found on infection control policies. Eight NICU required routine gowning on entry, two restricted sibling visiting and four restricted visiting by relatives and friends. Although routine bacteriological surveillance on staff or equipment was uncommon, serial cultures were carried out in infants from the body surface in six NICU and from the endotracheal aspirate in 17 NICU. Antiseptics used with technical procedures included iodine, chlorhexidine and alcohol used singly or in combination. Skin and umbilical cord care also varied between NICU. The literature was reviewed to determine the effectiveness or otherwise of some of the existing policies in the prevention or management of neonatal infection to encourage consensus towards a more rational approach to neonatal infection in Australia.
Anti-Bacterial Agents↗
The value of C-reactive protein measurement in the diagnosis of neonatal infection.
We examined whether serum C-reactive protein (CRP) measurements used in conjunction with leucocyte counts help in the diagnosis of perinatally acquired and nosocomial infections in very preterm newborn infants. One hundred and twenty-five infants born at a gestational age between 23 and 31 weeks with respiratory distress were studied at birth. A similar group of 85 infants beyond 3 days of age were also studied on 100 occasions for suspected infection. The diagnosis of proven or probable infection was correlated with abnormal haematology (leucopenia less than 5000/mm3, leucocytosis greater than 20,000/mm3 or ratio of immature forms to total neutrophils of greater than 0.2) and an elevated CRP (greater than 10 mg/L) singly or in combination. The sensitivity of an elevated CRP was relatively higher than abnormal haematology in both early and late infections and the sensitivity was highest when either test was abnormal. Similarly, the specificity, positive and negative predictive values and efficiency of an elevated CRP was relatively higher than abnormal haematology. The performance of the tests in 45 infants born at 23-28 weeks gestation was similar to that in 80 infants born at 29-31 weeks gestation. It was concluded that both CRP and leucocyte counts should be determined as they provide valuable information in the diagnosis of neonatal bacterial infection.
Bacterial Infections↗
A 12-year experience of retinopathy of prematurity in infants less than or equal to 28 weeks gestation or less than or equal to 1000 g birthweight.
This study reported the prevalence and severity of retinopathy of prematurity (ROP) in less than or equal to 28 weeks gestation or less than or equal to 1000 g birthweight infants over a 12-year period. Among 328 survivors of less than or equal to 28 weeks gestation, 30% had ROP, 12% had severe ROP of Stage 3 or worse, 5% had at least one blind eye and 3% were bilaterally blind. Among 201 survivors of less than or equal to 1000 g birthweight, the above abnormalities were found in 40, 16, 6 and 4% respectively. In both cohorts there was a significant increase in the prevalence of ROP and severe ROP between the period 1977-80 and 1981-84, but the lesser increase observed between the periods 1981-84 and 1985-88 was not statistically significant. The rates of ROP-induced blindness were not significantly different between the three 4-year periods. An inverse relationship was noted between the prevalence of ROP and gestational age. The results suggest a resurgence of ROP in less than or equal to 28 weeks or less than or equal to 1000 g infants, the cause of which is uncertain. In view of this trend, continued surveillance of ROP is warranted.
Birth Weight↗
Neurodevelopmental outcome, growth and health of extremely low-birthweight survivors: how soon can we tell?
A three-year cohort of extremely low-birthweight (ELBW, less than 1000g) survivors born between 1st January 1979 and 31st December 1981 were followed prospectively at one, two and five years of age, corrected for preterm birth. 57 of 110 infants survived, and 53 children were still alive at five years. The diagnoses of cerebral palsy, blindness, deafness and developmental delay fluctuated markedly according to age at developmental assessment. Although 13 of the 53 children were found to have impairments at five years, only seven were identified at one year, while 17 were identified at two years. In relation to the five-year assessment, impairments were underestimated at one year and developmental delay was overestimated at two years, which suggest that valid and reliable estimation of adverse neurodevelopmental sequelae among ELBW survivors may not be possible until school-age.
Blindness↗
Immunoglobulin and anti-Escherichia coli antibody in lower respiratory tract secretions from infants weighing less than 1500 g at birth.
Concentrations of immunoglobulins and anti-Escherichia coli antibody were studied longitudinally in tracheobronchial aspirates from 33 premature intubated neonates, median gestational age 27 weeks. Aspirates collected at birth contained IgG, IgA, and IgM in 100%, 93%, and 79% of samples, respectively. The median IgA concentration at birth was 0.7 micrograms/mg total protein and increased to 5.8 micrograms/mg protein by the sixth week. IgG and IgM antibodies to E coli were present in 90% and 30%, respectively, of tracheobronchial aspirates collected at birth. Samples from three of 28 neonates (11%) contained IgA anti-E coli antibody at birth, and the proportion with IgA antibody rose to 50% during the sixth week. Secretory component associated IgA and IgM were detectable in samples tested at birth and at 4 weeks of age, and secretory component associated anti-E coli antibody was present in aspirates from three of nine neonates studied at 4 weeks of age, but had not been detectable at birth.
Antibodies, Bacterial↗
Regional cerebral blood flow after hemorrhagic hypotension in the preterm, near-term, and newborn lamb.
Developmental changes in regional cerebral blood flow (CBF) responses to hemorrhagic hypotension during normoxia and normocapnia were determined using radioactively labeled microspheres to measure flow to the cortex, brainstem, cerebellum, white matter, caudate nucleus, and choroid plexus in three groups of chronically catheterized lambs: 90- to 100-d preterm fetal lambs (n = 9); 125- to 136-d near-term fetal lambs (n = 9); and newborn lambs 5- to 35-d-old (n = 8). Heart rate, central venous pressure, and arterial blood pressure were monitored continuously and arterial blood gas tensions, pH, Hb, and oxygen saturation together with regional CBF were measured periodically. Hemorrhagic hypotension produced a mean decrease in arterial blood pressure of 27 +/- 4, 23 +/- 2, and 41 +/- 4% in the three groups, respectively, whereas reinfusion of the lamb's blood resulted in a return to control blood pressure within 3% in all three groups. In the pre-term fetal lamb, CBF decreased significantly in all regions during hypotension. In the near-term fetal lamb, only blood flow to the cortex decreased significantly during hypotension. In the newborn lamb, only the choroid plexus demonstrated a significant decrease in blood flow during hypotension. The lower limit of regional CBF autoregulation was identical to the resting mean arterial pressure in fetal life but significantly lower in newborn lambs. These experiments demonstrate for the first time that vulnerability to hypotension decreases with increasing maturity and that the brainstem, the phylogenetically oldest region of the brain, is the least vulnerable to the effects of hypotension at any age in the lamb model.
Animals↗
Clinical experience with preterm formulas in very low birthweight infants.
Infants below 1500 g at birth were randomly assigned to receive one of two preterm infant formulars: S26 Low Birthweight (S26-LBW, 25 infants) or Enfalac Premature (EPF, 24 infants). They were either exclusively formula-fed (13 infants) or the formula was used to supplement their own mother's fresh breast milk (36 infants). The mean age when milk feeds were commenced was 7 days and the mean age when birthweight was regained was 12 days. The mean age when 2000 g was reached was 45 days at which time 10 (20%) infants were below the tenth centile on the intrauterine growth chart. None of the above variables were significantly different between the S26-LBW and EPF groups. However, the S26-LBW group established full enteral feeding significantly earlier compared to the EPF group (42 versus 64 d) and the number with adverse gastrointestinal effects was lower (4 versus 10 infants). Both preterm infant formulas supported a growth rate in excess of that in utero without stressing the infants' metabolic system. The growth rate of infants fed preterm breast milk supplemented with preterm infant formula was quantitatively similar to those exclusively fed preterm infant formula.
Bottle Feeding↗
Does dexamethasone suppress the ACTH response in preterm babies?
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Cosyntropin↗
The survival of extremely-low-birthweight infants in Victoria: 1982-1985.
A population-based survey of mortality in extremely-low-birthweight (500- to 999-g) infants was carried out in Victoria for the years 1982 to 1985. No increase in the number of extremely-preterm births occurred during that time. The still-birth rate fell from 498 still births per 1000 births in 1982-1983 to 403 still births per 1000 births in 1984-1985. The neonatal mortality in 1982-1985 was 638 deaths per 1000 live births, with no significant decline from that of the 1978-1981 cohort. The small increase in neonatal survivors was not associated with any change in the postneonatal death rate. Delivery in a level-3 unit was associated with a significantly better outcome. Multiple births made a major contribution to the extremely-low-birthweight group of infants.
Birth Weight↗