Doppler echocardiographic evaluation of right and left ventricular diastolic function in normal neonates.

Doppler echocardiograms of the tricuspid and mitral valves were recorded along with the electrocardiogram and respiration in 22 normal full-term neonates. A computer-interfaced digitizer pad was utilized to measure the following: peak E and A velocities (cm/s); E and A areas (the components of the total velocity-time integral in the early passive period of ventricular filling [E] and the late active period of atrial emptying [A], respectively) and the 1/3 area fraction (or the proportion of filling in the first 1/3 of diastole). All of the variables of right (tricuspid) versus left (mitral) ventricular filling were significantly different on the 1st day of life. Respective values were peak E velocity (cm/s) 44.6 +/- 10.0 (tricuspid) versus 53.2 +/- 9.3 (mitral), p less than 0.01; peak E/A ratio 0.84 +/- 0.14 versus 1.15 +/- 0.17, p less than 0.0001; E/total area 0.58 +/- 0.07 versus 0.63 +/- 0.05, p less than 0.005; E/A area ratio 1.05 +/- 0.23 versus 1.63 +/- 0.40, p less than 0.0001; 1/3 area fraction 0.31 +/- 0.04 versus 0.41 +/- 0.04, p less than 0.0001; peak A velocity (cm/s) 53.0 +/- 8.4 versus 47.6 +/- 5.8, p less than 0.05 and A/total area 0.57 +/- 0.09 versus 0.41 +/- 0.09, p less than 0.001; the mean heart rate (beats/min) was not significantly different: 121 +/- 8 versus 120 +/- 7. Most of the variables remained significantly different on the 2nd day of life, but the level of significance was the same or less for all measurements.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of peripheral intravenous cannulas in premature infants: a controlled study.

A randomized, controlled study was done to determine whether a 25-gauge steel needle or a 24-gauge Teflon catheter was preferable for the administration of peripheral intravenous fluids and medications to premature infants. A total of 58 cannulas--28 steel needles and 30 catheters--were used in 34 infants. The needles remained in place for 15.4 +/- 13.2 hours (mean +/- SD) and the Teflon catheters for 49.5 +/- 30.9 hours (mean +/- SD). All of the steel needles had to be removed because of infiltration whereas only 17/30 (57%) of the catheters infiltrated. A local inflammatory reaction, which was not related to infection, occurred with 11/30 (37%) of the Teflon catheters. Following removal, Staphylococcus epidermidis was grown from the culture of 1/19 steel needles and 1/25 catheters. In both instances this organism was thought to be a contaminant. Teflon catheters remain functional three times longer than steel needles with no apparent increase in complications. The use of these catheters, therefore, appears to be the preferred method for administering intravenous fluids to premature infants.

Effect of pneumothorax-induced systemic blood pressure alterations on the cerebral circulation in newborn dogs.

Pneumothorax has been associated with intraventricular hemorrhage in premature infants, although the mechanism for this relationship is not clear. Because alterations in cerebral blood flow are believed to be important in the pathogenesis of intraventricular hemorrhage, the effect of induced pneumothorax and subsequent evacuation on the cerebral circulation in 16 newborn dogs was evaluated. Continuous Doppler ultrasound was used to monitor changes in cerebral blood velocity. Pneumothorax was induced by slow infusion (5 cc/kg/min) or rapid infusion (5 to 10 seconds) of air to reduce mean arterial blood pressure to half of base-line levels. Both methods of pneumothorax induction resulted in significant elevations of central venous pressure and intrapleural pressure, whereas mean arterial blood pressure and cerebral blood velocity decreased significantly. In each group, the pneumothorax was evacuated either by slow withdrawal of air (10 cc/kg/min) or as rapidly as possible. Rapid evacuation of air resulted in an immediate increase in mean arterial blood pressure and cerebral blood velocity to supranormal levels. Slow evacuation led to a more gradual normalization of mean arterial blood pressure and cerebral blood velocity. It is suggested that the precipitous increases in mean arterial blood pressure and cerebral blood velocity following rapid evacuation of a tension pneumothorax may account for the observed association between pneumothorax and intraventricular hemorrhage in premature infants.

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).

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.

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.

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.

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.

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.

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.

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.

Effects of reinforcement, proximity, and orientation on verbal behavior of female schizophrenics.

Evaluated effects of reinforcement, proximity, and orientation on verbal behavior of female schizophrenics. Sixty-four inpatient state hospital volunteers (36 schizophrenics and 33 hospitalized controls) either were reinforced verbally or nonreinforced for construction of appropriate sentences. Also, participants were exposed to near or far proximity as well as direct or indirect orientation. Results indicated that schizophrenics performed best in the indirect orientation condition. While no differential group effects were seen across diagnosis, participants on the average responded more effectively when reinforced. These findings are contradictory to those reported in earlier studies of verbal conditioning in schizophrenics. Discussed were the detrimental effects of attentional demands on verbal conditioning in schizophrenics and the effectiveness of verbal reinforcement across hospitalized patients.

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.

Serum potassium changes following packed red cell transfusions in newborn infants.

We studied the effect of packed red cell transfusions on serum potassium levels in sick newborn infants. In 11 transfusions the infants' serum potassium levels fell from a mean of 5.1 +/- 1.2 mEq per 1 (SD) to 4.9 +/- 1.2 mEq per 1 within 1 hour of the transfusion. Plasma potassium in stored packed red cells rose markedly within 48 hours of drawing. In spite of this, the transfusion of 10 ml per kg of packed red cells did not affect the serum potassium concentration in the newborn infant.

Rickets associated with cholestasis and parenteral nutrition in premature infants.

Fourteen premature infants on prolonged total parenteral nutrition (TPN) exhibited radiographic evidence of rickets. All had received supplementary doses of vitamin D that, in retrospect, may have been inadequate. Cholestasis and rickets resolved in the 10 surviving infants after they were started on oral feelings, which corrected their hypophosphatemia. On the assumption that they might be deficient in vitamin D, they were given high doses of it. In retrospect, it appears probable that rickets in such cases is caused by hypophosphatemia, due to inadequate phosphorus intake, and that vitamin D deficiency is of little or no importance.

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.