Early postnatal hypotension is not associated with indicators of white matter damage or cerebral palsy in extremely low gestational age newborns.

OBJECTIVE: To evaluate, in extremely low gestational age newborns (ELGANs), relationships between indicators of early postnatal hypotension and cranial ultrasound indicators of cerebral white matter damage imaged in the nursery and cerebral palsy diagnoses at 24 months follow-up. STUDY DESIGN: The 1041 infants in this prospective study were born at <28 weeks gestation, were assessed for three indicators of hypotension in the first 24 postnatal hours, had at least one set of protocol cranial ultrasound scans and were evaluated with a structured neurological exam at 24 months corrected age. Indicators of hypotension included: (1) lowest mean arterial pressure (MAP) in the lowest quartile for gestational age; (2) treatment with a vasopressor; and (3) blood pressure lability, defined as the upper quartile of the difference between each infant's lowest and highest MAP. Outcomes included indicators of cerebral white matter damage, that is, moderate/severe ventriculomegaly or an echolucent lesion on cranial ultrasound and cerebral palsy diagnoses at 24 months gestation. Logistic regression was used to evaluate relationships among hypotension indicators and outcomes, adjusting for potential confounders. RESULT: Twenty-one percent of surviving infants had a lowest blood pressure in the lowest quartile for gestational age, 24% were treated with vasopressors and 24% had labile blood pressure. Among infants with these hypotension indicators, 10% percent developed ventriculomegaly and 7% developed an echolucent lesion. At 24 months follow-up, 6% had developed quadriparesis, 4% diparesis and 2% hemiparesis. After adjusting for confounders, we found no association between indicators of hypotension, and indicators of cerebral white matter damage or a cerebral palsy diagnosis. CONCLUSION: The absence of an association between indicators of hypotension and cerebral white matter damage and or cerebral palsy suggests that early hypotension may not be important in the pathogenesis of brain injury in ELGANs.

Fetal schistocytic hemolytic anemia and umbilical vein varix.

A rare case of schistocytic hemolytic anemia presenting in a fetus secondary to a varix of the intra-abdominal umbilical vein is reported. A patient was referred to our hospital at 32 weeks of gestation because of an abnormal hypoechoic finding in the fetal liver. Prenatal ultrasound showed turbulent flow through a 12-mm diameter dilatation of the fetal intra-abdominal umbilical vein consistent with a varix. Cardiomegaly also was noted. At birth, the 1098-g, growth-retarded, male neonate was in severe congestive heart failure secondary to anemia as the initial hemoglobin was 5 g/dL. Additional evaluation found the anemia to be secondary to schistocytic hemolysis. After the neonate received a transfusion of packed erythrocytes and supportive care, the anemia quickly resolved, and he was discharged to home doing well after a 6-week stay in the neonatal intensive care unit. Prompt recognition of the varix prenatally and thorough evaluation of the newborn postnatally led to appropriate diagnosis and treatment.

Need for urgent delivery after third-trimester amniocentesis.

OBJECTIVE: To estimate the risk of need for urgent delivery after third-trimester amniocentesis as currently done using ultrasound guidance to assess fetal lung maturity. METHODS: Ultrasound records of women scheduled for third-trimester amniocenteses to assess fetal lung maturity from February 1990 through October 1997 were reviewed for possible complications during or immediately after procedures. Collected data included gestational age, indication for the procedure, number of needle passes, transplacental passage, needle gauge, and fluid color. The primary outcome examined was procedure-related complications that required emergency delivery or the decision to deliver before completion of maturity studies. Infants who developed hyaline membrane disease leading to neonatal intensive care admission were also identified. RESULTS: During the 7 1/2-year study period, 962 amniocenteses were done to assess lung maturity. Complete data were not available for 49 cases. Of the remaining 913 procedures, 15 (1.6%) were unsuccessful (needle pass without collecting fluid). Forty-one infants were delivered spontaneously or by cesarean on the same day as the procedure. However, complications that required delivery were identified in only six cases, an incidence of 0.7% (95% confidence interval = 0.16, 1.24). Complications included fetal heart rate abnormalities (n = 3), placental bleeding (n = 1), abruptio placentae (n = 1), and uterine rupture (n = 1). Only one of six complications had a single needle pass with clear fluid collected. Hyaline membrane disease occurred in 14 neonates, including two with mature indices. CONCLUSION: Although complications that required urgent delivery after third-trimester amniocentesis are rare, the risks of the procedure should be carefully weighed against the benefits.

The impact of fetal compromise on outcome at the border of viability.

OBJECTIVE: Our goal was to evaluate the impact of fetal compromise on the outcome of borderline viable babies. STUDY DESIGN: All 142 babies born in our hospital from 1990 to 1995 with a gestational age of 23 to 25 weeks were included. Fetal compromise was considered present if one of the following was documented: a major anomaly, congenital sepsis, chronic intrauterine infection, intrauterine drug exposure, congenital anemia, severe growth restriction, fetal acidosis, or cardiorespiratory and neurologic depression in the delivery room. RESULTS: The 43 babies who had at least one cause of fetal compromise had a lower birth weight (p < 0.001), but there were no other differences in demographics or complications of prematurity. The survival rate was significantly better for babies free of fetal compromise (75% vs 33%, p < 0.001), particularly for babies born at 23 weeks of gestation (75% vs 6%, p < 0.001). For surviving babies free of fetal compromise, the outcome at 23 weeks was comparable to that at 24 to 25 weeks for major causes of long-term neurologic morbidity. CONCLUSIONS: Like advancing gestational age and increasing birth weight, the absence of fetal compromise has a major beneficial impact on the outcome of borderline viable babies that might be important when decisions are made about the appropriate level of support.

Isolated lateral ventricular asymmetry in very low-birth-weight infants: a left-sided lesion?

We prospectively performed serial cranial ultrasonography to determine the incidence of asymmetry of the lateral ventricles in very low-birth-weight (VLBW) infants (500-1500 g) who did not have evidence of other intracranial pathology. Of the 490 babies scanned, 354 were free of other pathology and 41 (11.6%) had isolated ventricular asymmetry. In 10 infants, the asymmetry was seen on the initial scan and in 31, it developed subsequently. In 19 infants, the ventricular asymmetry resolved and in 22 infants it persisted until hospital discharge. In no case was progressive enlargement of the ventricles noted. There was a striking tendency of the larger ventricle to be on the left side (33 L>R, 8 R>L). Compared with a control group of babies matched for birth weight and gestational age who had persistently negative scans, there were no differences in Apgar scores, cesarean section rate, gender distribution, prenatal steroid exposure, or complications of prematurity except for an increased incidence of respiratory distress syndrome requiring surfactant in the group with ventricular asymmetry (63% vs. 29%, p = 0.04). Ventricular asymmetry is common in VLBW infants, but whether it is an incidental finding or represents subtle brain injury is unknown.

Current gestational age-related incidence of major intraventricular hemorrhage.

The overall incidence of germinal matrix intraventricular hemorrhage (GMIVH) for an inborn population of 250 very low birth weight infants from 1991 through 1993 was 20%; the incidence of major GMIVH was 5.2%. Of infants < or = 25 weeks, 60% survived and 94% of the survivors were free of major GMIVH, whereas 94% of infants > or = 25 weeks survived and 99% had no major GMIVH.

Survival and short-term outcome in newborns of 23 to 25 weeks' gestation.

OBJECTIVES: We determined which factors are associated with survival and good short-term neurologic outcome in newborns of 23 to 25 weeks' gestation. STUDY DESIGN: We retrospectively reviewed the charts of all (n = 82) infants born alive at our hospital at 23 to 25 weeks' gestation from 1988 through 1991. We used univariate and multiple logistic regression analysis to compare survivors at hospital discharge with nonsurvivors and those with and without good short-term neurologic outcome. RESULTS: Survival rates were 19%, 59%, and 65% at 23, 24, and 25 weeks' gestation, respectively. A total of 90% of survivors had good short-term neurologic outcome. On multiple logistic regression analysis, female sex (odds ratio 8.7, 95% confidence limits 2.2 and 34), larger birth weight (odds ratio 2.5 per 100 gm increment, 95% confidence limits 1.3 and 4.9), and more advanced gestational age (odds ratio 5.3, 95% confidence limits 1.2 and 22 for 24 weeks; odds ratio 3.8, 95% confidence limits 0.6 and 22 for 25 weeks) were associated with survival. Female sex, more advanced gestational age, and larger birth weight were also associated with good short-term neurologic outcome. CONCLUSIONS: Good short-term neurologic outcome is possible in many survivors in this gestational age range. Factors other than gestational age may be considered when intervention in these pregnancies is contemplated.

Severe retinopathy of prematurity and steroid exposure.

During a 3-year period (1988 through 1990) an increase was observed in the number of infants born at 23- to 26-weeks' gestation who required cryotherapy for severe retinopathy of prematurity (0/20, 1988; 3/14, 1989; 6/18, 1990; P = .015). Inasmuch as this was not related to improved survival, a retrospective case-control study was conducted to try to explain this observation. Of 52 surviving infants who had been born at 23 to 26 weeks' gestation, 9 required cryotherapy and the other 43 served as control subjects. There were no differences between groups in birthweight, gestational age, or the number of infants with hyaline membrane disease, intraventricular hemorrhage, or hydrocephalus. Factors related to the need for cryotherapy included patent ductus arteriosus (P = .046), mechanical ventilation for more than 21 days (P = .045), and the use of steroids for lung disease (P < .001). In this neonatal intensive care unit, steroids are administered according to the attending neonatologist's preference. Inasmuch as steroids are considered only for infants still ventilator dependent at 21 days, this group was analyzed separately (n = 36). Of the 21 factors examined, only the use of steroids for lung disease was associated with the need for cryotherapy (P < .001).

Respiratory complications associated with cryotherapy in premature infants.

We reviewed the frequency of respiratory complications associated with cryotherapy in 14 premature infants who underwent 17 cryotherapy procedures. Five of the procedures were performed on infants already being mechanically ventilated. Two of these infants required increased ventilatory support during and following the procedure for decreased spontaneous respirations. For the 12 procedures performed on 11 infants who were not being mechanically ventilated at the time of cryotherapy, four infants had no complications, three infants had minor respiratory deteriorations, and five infants required positive pressure ventilation for severe apnea and bradycardia episodes (one just after narcotic administration, four during the procedure). Excluding the three infants (five procedures) who were already receiving mechanical ventilation at the time of cryotherapy, the infants who had severe apnea requiring the initiation of positive pressure ventilation weighed less and were younger than those infants not having a serious respiratory complication (p less than 0.05).

Reducing neonatal transfusions.

In an attempt to prevent blood transfusions from being ordered unnecessarily in our neonatal intensive care unit (NICU), we developed transfusion guidelines and prospectively evaluated their impact on our transfusion practices. Initially, 17% of our packed red blood cell transfusions (PRBCT) did not meet our guidelines. However, 6 months following development of the guidelines, this decreased to 9%, and 12 months later, it decreased to 1%. Although the guidelines are clearly arbitrary, they do provide for consistency within our NICU and a method of evaluating our own use of PRBCT.

Cerebral blood flow velocity in normal, full-term newborns is not related to ductal closure.

OBJECTIVE: To correlate changes in blood flow velocity in the anterior and middle cerebral arteries with closure of the ductus arteriosus in normal, full-term newborns during the first 2 days following delivery. DESIGN: Survey. SETTING: Large community hospital. PARTICIPANTS: Twenty-three normal, full-term neonates. SELECTION PROCEDURES: Volunteer sample. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: We measured blood flow velocity in the anterior and middle cerebral arteries, cardiac output, and patency of the ductus arteriosus using pulsed Doppler, M-mode, and real-time ultrasound. The initial examination was performed at (mean +/- SD) 7.6 +/- 2 hours and the second examination was performed at 30 +/- 3 hours. The systolic, diastolic, and mean blood flow velocity in the anterior and middle cerebral arteries increased significantly from day 1 to day 2. Cardiac output did not change significantly (252 +/- 49 vs 279 +/- 69 cm3/kg per minute). Thirteen newborns on day 1, but only two newborns on day 2, had echocardiographic evidence of a patent ductus arteriosus. Newborns whose ductus was already closed on day 1 had similar increases in blood flow velocity in the anterior and middle cerebral arteries from day 1 to day 2 compared with newborns whose ductus had closed from day 1 to day 2. CONCLUSION: The normal increase in blood flow velocity in the anterior and middle cerebral arteries in the first 2 days following delivery is not related to changes in cardiac output or ductal closure.

Complications associated with central venous catheters inserted in critically ill neonates.

OBJECTIVE: To assess the incidence and spectrum of complications associated with central venous catheter (CVC) placement in the critically ill infant. DESIGN: A prospective study of all babies hospitalized in a neonatal intensive care unit (NICU) from January 1989 to December 1989. Potential risk factors associated with infection were evaluated by a case-control comparison. SETTING: Conducted at a university-affiliated, tertiary care community hospital. PATIENTS: Neonates requiring intensive care and a central venous catheter. Controls consisted of noninfected babies. RESULTS: Of 263 critically ill neonates, only 13 (4.9%) required a CVC insertion. Seventeen CVCs were placed in these 13 neonates for a total duration of 600 days (median, 32 days/cannula). Fifteen (88%) of these cannulas had one or more complications during its catheter life including dislodgement or leakage (53%), occlusion or thrombosis (47%), infections (29%), or minor bleeding (12%). Five babies (29%) developed 6 episodes of bloodstream infection including 3 sporadic cases due to Staphylococcus epidermidis and a cluster of fungemia due to Malassezia furfur associated with lipid emulsion therapy. Infants with a CVC-associated infection were a younger gestational age (24 weeks versus 32 weeks, p = .04) and weighed less at birth (580 g versus 1285 g, p = .02). The overall rate of bloodstream infection was one episode per 100 days of catheter use. CONCLUSIONS: CVCs may be lifesaving to a critically ill neonate, but complications occur frequently. Use must be restricted to infants in whom alternate delivery routes of intravenous therapy or support are otherwise unavailable.

A comparison of chromogen test strip (Chemstrip bG) and serum glucose values in newborns.

Although glucose oxidase-peroxidase chromogen test strips are frequently used to estimate serum glucose values in newborns, previous studies have not evaluated multiobserver variability of test strip readings and have included few infants with hypoglycemia. We compared values of 272 samples of serum glucose with values simultaneously obtained by chromogen test strips (Chemstrip bG) in newborns. The diagnostic sensitivity of a chromogen test strip less than 2.2 mmol/L for predicting a serum glucose level less than 1.9 mmol/L was 86% (95% confidence interval [CI], 75% to 94%), with 78% specificity (95% CI, 73% to 84%). The positive predictive value in our specimens, with a 21% prevalence of serum glucose levels less than 1.9 mmol/L, was 52% (95% CI, 41% to 62%), with a negative predictive value of 95% (95% CI, 91% to 100%). Fifty-eight of our serum glucose values were less than 1.9 mmol/L and the levels obtained by chromogen test strip were greater than or equal to 2.2 mmol/L in 8 of these cases. Review of these 8 cases showed that a delay in performing the laboratory glucose oxidase serum glucose could account for the discrepancy in 2 cases. Chromogen test strips are readily available and easy to use, but more sensitive, specific, accurate, and precise methods of serum glucose screening in newborns are needed.

Effect of birth order on intraventricular hemorrhage in very low birth weight twins.

We evaluated the effect of birth order on the incidence and severity of intraventricular hemorrhage in 29 sets of very low birth weight twins (1500 g or less). Intraventricular hemorrhage occurred in 55% of first-presenting twins and 62% of second-presenting twins. The incidence of minor intraventricular hemorrhage (grades I and II) was 41% for first twins and 52% for second twins, whereas the incidence of major intraventricular hemorrhage (grades III and IV) was 14 and 10%, respectively. None of these differences reached statistical significance. We conclude that birth order does not appear to have a major effect on the incidence or severity of intraventricular hemorrhage in very low birth weight twins.

Intrauterine skull depression and intracranial hemorrhage in a premature infant.

The authors describe a case of a premature infant born with a parietal skull depression who suffered an intraventricular hemorrhage and an ipsilateral intracerebral injury. At 21 months of life the infant's gross motor milestones were delayed and he had moderate spastic hemiplegia. Although skull depressions at birth are usually benign, they may be associated with long-term neurologic sequelae.

The effect of intraventricular blood on cerebral blood flow in newborn dogs.

We investigated the effect of intraventricular blood on cerebral blood flow in the newborn puppy by infusing autologous blood into the lateral ventricle to produce and maintain an intraventricular pressure of approximately 15 mm Hg (mild insult), 30 mm Hg (moderate insult), or 50 mm Hg (severe insult) for 20 min. As the intraventricular pressure increased, flow decreased progressively to all areas of the brain directly proportional to the cerebral perfusion pressure. On return of the intraventricular pressure to baseline level, cerebral blood flow normalized despite the continued presence of a large amount of blood within the lateral ventricles. We suggest that blood within the ventricular system can result in a significant acute reduction of cerebral blood flow which appears to be mediated through the effect on cerebral perfusion pressure.

Incidence and severity of intraventricular hemorrhage: 1981-1984.

We have examined the trend in the incidence and mortality of intraventricular hemorrhage (IVH) in low birthweight infants from 1981 through 1984. During this time we admitted 407 infants in the first week of life with a birthweight less than or equal to 1500 gm in whom a cranial ultrasonogram or autopsy had been performed. Though the mean birthweight and gestational age, proportion of infants who were inborn, and percentage of infants requiring mechanical ventilation did not change over the 4 years, cesarean deliveries were performed more frequently (P less than .001). The overall incidence of IVH was 62% in 1981, 56% in 1982, 49% in 1983, and 58% in 1984, thus no significant trend was evident. Although the incidence of minor hemorrhages (grades I and II) remained relatively constant, there was a decrease in the incidence of grade III IVH (1981, 11%; 1984, 2%, P = .01). The incidence of grade IV hemorrhage did not change during the 4 years and ranged from 7 to 9%. Mortality rate for all infants weighing less than or equal to 1500 gm and for infants with a minor hemorrhage remained unchanged; however, the mortality rate for infants with a major hemorrhage (grade III or IV) tended to decrease (P = .07). We conclude that although some minor changes in the incidence and mortality have occurred, IVH continues to be a major problem in very-low-birthweight infants at our institution.