Major cardiorespiratory events do not increase after immunizations, eye exams, and other stressors in most very low birth weight infants

BACKGROUND

Increased cardiorespiratory events with bradycardia and oxygen desaturation have been reported in very low birthweight (VLBW) infants following stressors such as immunizations. These events are difficult to quantify and may be mild. Our group developed an automated algorithm to analyze bedside monitor data from NICU patients for events with bradycardia and prolonged oxygen desaturation (BDs) and used this to compare BDs 24 hours before and after potentially stressful interventions.

METHODS

We included VLBW infants from 2012-2017 with data available around at least one of four interventions: two-month immunizations, retinopathy of prematurity (ROP) examinations, ROP therapy, and inguinal hernia surgery. We used a validated algorithm to analyze electrocardiogram heart rate and pulse oximeter saturation data (HR, SpO2) to quantify BD events of HR <  100 beats/minute for≥4 seconds with oxygen desaturation <  80%SpO2 for≥10 seconds. BDs were analyzed 24 hours before and after interventions using Wilcoxon rank-sum tests.

RESULTS

In 354 of 493 (72%) interventions, BD frequency stayed the same or decreased in the 24 hours after the event. An increase of at least five BD's occurred in 17/146 (12%) after immunizations, 85/290 (29%) after ROP examinations, 4/33 (12%) after ROP therapy, and 3/25 (12%) after hernia surgery. Infants with an increase in BDs after interventions had similar demographics compared to those without. More infants with an increase in BDs following immunizations were on CPAP or caffeine than those without.

CONCLUSIONS

Most VLBW infants in our cohort had no increase in significant cardiorespiratory events in the 24 hours following potentially stressful interventions.

Achievement of maturational milestones among very low birth weight infants

BACKGROUND

Very low birth weight (VLBW) infants must achieve several maturational milestones to be discharged home from the NICU.

OBJECTIVE

Describe the timing of maturational milestones in VLBW infants and the impact of clinical variables and milestone achievement on postmenstrual age (PMA) at discharge.

METHODS

For VLBW infants without severe lung disease discharged home from a level IV NICU, we assessed PMA at the achievement of thermoregulation, cardiorespiratory stability, feeding, and discharge.

RESULTS

In 400 infants (median GA 28.4 weeks), lower birth weight, white race, and having multiple comorbidities of prematurity predicted later discharge PMA. The most common milestone sequence was CPAP discontinuation, caffeine discontinuation, thermoregulation, apnea resolution, and full oral feeds. PMA at apnea resolution and full oral feeds correlated highly with discharge PMA.

CONCLUSIONS

In a single-center VLBW cohort, comorbidities of prematurity impacted the timing of NICU discharge through delay in oral feeding and cardiorespiratory stability.

Abnormal heart rate characteristics are associated with abnormal neuroimaging and outcomes in extremely low birth weight infants

OBJECTIVE

Brain injury in preterm infants may lead to an inflammatory response and central nervous system dysfunction reflected by abnormal heart rate characteristics (HRC). We hypothesized that a continuously monitored HRC index reflecting reduced HR variability and decelerations correlates with abnormal neuroimaging and outcomes in extremely low birth weight infants (ELBW).

STUDY DESIGN

We analyzed the average HRC index within 28 days after birth (aHRC28) and head ultrasound (HUS) in 384 ELBW infants. In 50 infants with brain magnetic resonance imaging (MRI) and 70 infants with Bayley neurodevelopmental testing at 1 year of age, we analyzed the relationship between aHRC28, MRI abnormalities and low Bayley scores.

RESULT

aHRC28 was higher in infants with severe HUS abnormalities (2.65±1.27 for Grade III-IV intraventricular hemorrhage (IVH) or cystic periventricular leukomalacia (cPVL) versus 1.72±0.95 for normal or Grade I-II IVH, P<0.001). Higher aHRC28 was also associated with white matter damage on MRI and death or Bayley motor or mental developmental index <70. Associations persisted after adjusting for gestational age, birth weight and septicemia. For every one point increase in aHRC28, the odds ratio of death or Bayley score <70 was 2.45 (95% CI 1.46, 4.05, P<0.001).

CONCLUSION

A continuously monitored HRC index provides an objective, noninvasive measure associated with abnormal brain imaging and adverse neurologic outcomes in ELBW infants.

Improving cognitive development of low-birth-weight premature infants with the COPE program: a pilot study of the benefit of early NICU intervention with mothers

The purpose of this pilot study was to evaluate the effectiveness of a parent-focused intervention program (COPE) on infant cognitive development and maternal coping. A randomized clinical trial was conducted with 42 mothers of low-birth-weight (LBW) premature infants hospitalized in a neonatal intensive care unit (NICU), with follow-up at 3 months' and 6 months' corrected ages. COPE mothers received the four-phase educational-behavioral program that began 2-4 days postbirth and continued through 1 week following discharge from the NICU. Comparison mothers received audiotaped information during the same four time frames. Results indicated that COPE infants had significantly higher mental development scores at a 3 months' corrected age (M = 100.3) than did the comparison infants (M = 93.9), and this difference widened at 6 months' corrected age, with COPE infants scoring 14 points higher. COPE mothers were significantly less stressed by the NICU sights and sounds and had significantly stronger beliefs about what behaviors and characteristics to expect from their premature infants. Findings from this study support the need for further testing of early NICU interventions with parents to determine their effectiveness on parental coping and infant developmental outcomes.

Early dexamethasone-attempting to prevent chronic lung disease

BACKGROUND

We previously demonstrated improved survival and early outcomes in a pilot trial of 2 doses of intravenous dexamethasone for infants with surfactant-treated respiratory distress syndrome. (1) A multicenter, randomized, double-blind trial was undertaken to confirm these results.

METHODS

Infants <30 weeks' gestation were eligible if they had respiratory distress syndrome, required mechanical ventilation at 12 to 18 hours of age, and had received at least 1 dose of exogenous surfactant. Infants were excluded if sepsis or pneumonia was suspected or if congenital heart disease or chromosomal abnormalities were present. A total of 384 infants were enrolled-189 randomized to dexamethasone (.5mg/kg birth weight at 12-18 hours of age and a second dose 12 hours later) and 195 to an equal volume of saline placebo.

RESULTS

No differences were found in the dexamethasone versus placebo groups, respectively, regarding the primary outcomes of survival (79% vs 83%), survival without oxygen at 36 weeks' corrected gestational age (CGA; both 59%), and survival without oxygen at 36 weeks' CGA and without late glucocorticoid therapy (46% vs 44%). No significant differences between the groups in estimates from Kaplan-Meier survival analyses were found for median days on oxygen (50 vs 56 days), ventilation (20 vs 27 days), days to regain birth weight (15.5 vs 14 days), or length of stay (LOS; 88 vs 89 days). Infants given early dexamethasone were less likely to receive later glucocorticoid therapy for bronchopulmonary dysplasia during their hospitalization (27% vs 35%). No clinically significant side effects were noted in the dexamethasone group, although there were transient elevations in blood glucose and blood pressure followed by a return to baseline by study day 10. Among infants who died (40 vs 33), there were no differences in the median days on oxygen, ventilation, nor LOS. However, in survivors (149 vs 162), the following were observed: median days on oxygen 37 versus 45 days, ventilation 14 versus 19 days, and LOS 79 versus 81 days, for the dexamethasone versus placebo groups, respectively.

CONCLUSIONS

This dose of early intravenous dexamethasone did not reduce the requirement for oxygen at 36 weeks' CGA and survival was not improved. However, early dexamethasone reduced the use of later prolonged dexamethasone therapy, and among survivors, reduced the median days on oxygen and ventilation. We conclude that this course of early dexamethasone probably represents a near minimum dose for instituting a prophylactic regimen against bronchopulmonary dysplasia.

Respiratory syncytial virus and premature infants born at 32 weeks' gestation or earlier: hospitalization and economic implications of prophylaxis

OBJECTIVES

To assess the risk of hospitalization associated with respiratory syncytial virus (RSV) and to estimate the economic impact of RSV prophylaxis with either RSV immune globulin (RSV-Ig) or RSV monoclonal antibody (palivizumab) on a cohort of preterm infants born at 32 weeks' gestation or earlier.

DESIGN

Historical cohort study.

SETTING

A 12-county neonatal network served by the regional center in Rochester, NY.

PARTICIPANTS

One thousand twenty-nine infants born at 32 weeks' gestation or earlier followed up until 1 year of corrected age.

MAIN OUTCOME MEASURES

Rate of hospitalization with an RSV-associated illness; cost per hospitalization prevented resulting from either form of RSV prophylaxis.

RESULTS

The probability of hospitalization with an RSV-associated illness for infants born at 32 weeks' gestation or earlier was estimated at 11.2%. The incidence of RSV hospitalization increased with decreasing gestational age (13.9% vs 4.4% for infants born at < or =26 weeks' gestation vs those born at 30-32 weeks' gestation). Infants requiring respiratory support at 36 weeks of postconceptual age (PCA) or older had a higher hospitalization rate (16.8% vs 6.2%), longer hospital stays, and higher hospital charges than infants requiring respiratory support at less than 36 weeks of PCA. For infants requiring respiratory support at less than 36 weeks of PCA, the incidence of RSV hospitalization still increased with decreasing gestational age (10.2% vs 4.3% for infants < or =26 weeks' gestation vs those 30-32 weeks' gestation). Analysis indicated that both forms of RSV prophylaxis would increase the net cost of care for all groups. Palivizumab was more cost-effective than RSV-Ig for preventing RSV hospitalization among infants who required respiratory support at less than 36 weeks of PCA, especially those born at 26 weeks' gestation or earlier. Overall, RSV-Ig was more cost-effective than palivizumab for infants requiring respiratory support at 36 weeks of PCA or older.

CONCLUSIONS

This analysis suggests that available forms of RSV prophylaxis would increase the net cost of care not only for the entire cohort but for each of the subgroups studied. However, the RSV hospitalization rate and the cost-effectiveness of prophylaxis varied markedly by subgroup.

Vascular endothelial growth factor in pulmonary lavage fluid from premature infants: effects of age and postnatal dexamethasone

Corticosteroids are used to ameliorate bronchopulmonary dysplasia (BPD). They also affect normal development, including the expression of growth factors such as vascular endothelial growth factor (VEGF). Deep pulmonary lavage specimens were collected on days 1, 3, 7 and 28 of life in 40 infants of <34 weeks of gestation at birth during a randomized controlled trial of two doses of dexamethasone (DEX) at 12 and 24 h of age for BPD prophylaxis. VEGF was measured by enzyme-linked immunosorbent assay. The 18 DEX and 21 control subjects had similar gestations, birth weights and oxygen requirements at study entry. Lavage VEGF tripled between day 1 and 3 in both groups. The day 7 levels were higher in DEX subjects than in controls. DEX and control values were similar on day 28. Higher lavage VEGF levels on days 1 and 3 were also correlated with lower gestational age at birth. Lavage VEGF levels were not associated with the development of BPD. We speculate that these DEX- and age-associated changes in VEGF may affect pulmonary angiogenesis.

Lipid intolerance in neonates receiving dexamethasone for bronchopulmonary dysplasia

BACKGROUND

We hypothesized that dexamethasone induces hypertriglyceridemia (triglyceride levels >2.82 mmol/L [250 mg/dL]) and increases free fatty acid (FFA) levels and that steroid-induced hypertriglyceridemia is associated with hyperinsulinemia and elevated FFA levels.

OBJECTIVE

To study the effect of dexamethasone sodium phosphate on lipid metabolism in neonates receiving intravenous lipids.

DESIGN

A prospective cohort study with patients serving as their own controls.

SETTING

Neonatal Intensive Care Unit, Children's Hospital at Strong, Rochester, NY.

METHODS

All neonates younger than 29 weeks' gestational age at birth receiving 3 g/kg per day of intravenous lipids who were to start dexamethasone therapy for bronchopulmonary dysplasia were eligible. Exclusion criteria included neonates with active infection, prior hypertriglyceridemia, bleeding manifestations, recent surgery, thyroid medication, and human recombinant insulin intravenous infusion therapy. Ten neonates were studied. Blood was drawn for triglyceride, FFA, and insulin assays before initiating and at 1, 2, 3, and 5 days after starting dexamethasone therapy. On day 3, dexamethasone dosage was decreased as per protocol. Intravenous lipid intake was kept constant. Statistical analysis was done using a paired t test.

RESULTS

Six of 10 neonates reached a state of hypertriglyceridemia (95% confidence interval, 26.2%-87.8%). The mean average increase in triglycerides, insulin, and FFA levels in neonates receiving 3 g/kg per day of intravenous lipids after initiation of dexamethasone therapy was 0.75 mmol/L (66.6 mg/dL) (P=.007), 127 pmol/L (P = .006), and 47.5 micromol/L (P = .65), respectively. Six neonates who developed hypertriglyceridemia had significantly elevated mean peak FFA levels (918.3 micromol/L) prior to developing hypertriglyceridemia compared with 4 neonates (mean peak FFA levels, 380.2 micromol/L) who had triglyceride levels lower than 2.82 mmol/L (250 mg/dL) (P = .002).

CONCLUSION

We conclude that dexamethasone induces hypertriglyceridemia in the presence of hyperinsulinemia and increased FFA levels.

Disseminated coagulopathy associated with transtorcular embolization of vein of Galen aneurysm in a neonate

We describe in this report the development of disseminated intravascular coagulopathy in a neonate after transtorcular embolization of an unusual vein of Galen aneurysm. This rare but potentially fatal complication associated with transtorcular embolization should be considered in decision-making and prognostic evaluation processes, especially in neonates with severe heart failure.

Fibronectin expression in bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic fibrotic lung disease of neonates. Fibronectin (FN), a component of the extracellular matrix, is increased in the tracheobronchial effluent of neonates destined to develop BPD. Pulmonary FN is derived from plasma and local cellular synthesis. In order to identify which pulmonary cells synthesize FN and to test the hypothesis that FN is more abundant in lungs with BPD, we examined the distribution of pulmonary FN by in situ hybridization (for mRNA) and immunohistochemistry (for protein) in neonatal autopsy lung specimens, comparing lungs with BPD to those without. We used a staging system in which BPD is characterized by disruption of alveolar architecture, severe vascular changes, airway epithelial necrosis, smooth muscle hypertrophy, and peribronchial fibrosis. FN mRNA and protein were found in vascular endothelium, macrophages, fibroblasts, vascular and airway smooth muscle, and chondrocytes as well as in the pulmonary parenchyma in neonates with and without BPD. Hyaline membranes, when present, immunostained intensely for FN protein. FN mRNA was not seen in airway epithelial cells of either group. FN mRNA and protein were first increased in early acute BPD with their levels appearing greatest during the chronic reparative stage of BPD. In long-standing "healed" BPD, lower levels of FN mRNA and protein were seen. These findings are consistent with the association of increased FN with adult fibrotic lung disease and the previously reported increase in FN tracheal effluent levels in infants with BPD. Our results suggest an important role for pulmonary cell-derived FN in the early inflammatory and later proliferative stages of BPD.

Comparison of two strategies for surfactant prophylaxis in very premature infants: a multicenter randomized trial

INTRODUCTION

Previous trials of surfactant therapy in premature infants have demonstrated a survival advantage associated with prophylactic therapy as an immediate bolus, compared with the rescue treatment of established respiratory distress syndrome. The optimal strategy for prophylactic therapy, however, remains controversial. When administered as an endotracheal bolus immediately after delivery, surfactant mixes with the absorbing fetal lung fluid and may reach the alveoli before the onset of lung injury. This approach, however, causes a brief delay in the initiation of standard neonatal resuscitation, including positive pressure ventilation, and is associated with a risk for surfactant delivery into the right main stem bronchus or esophagus. As an alternative approach, surfactant prophylaxis may be administered in small aliquots soon after resuscitation and confirmation of endotracheal tube position. Although this strategy has substantial logistical advantages in clinical practice, its efficacy has not been established.

OBJECTIVE

The purpose of this study was to determine whether the established benefits of the immediate bolus strategy for surfactant prophylaxis could still be achieved using a postventilatory aliquot strategy after initial standard resuscitation and stabilization.

DESIGN

Multicenter randomized clinical trial with patients randomized before delivery to immediate bolus or postventilatory aliquot therapy.

PARTICIPANTS

Inborn premature infants delivered to mothers at an estimated gestational age of 24[0/7] to 28[6/7] weeks.

INTERVENTIONS

Those infants who were randomized to the immediate bolus strategy were intubated as rapidly as possible after birth, and a 3-mL intratracheal bolus of calf lung surfactant extract (Infasurf) was administered before the initiation of positive pressure ventilation. Those infants who were randomized to the postventilatory aliquot strategy received standard resuscitation measures with intubation by 5 minutes of age, if not required earlier. At 10 minutes after birth, 3 mL of surfactant was administered in 4 divided aliquots of 0.75 mL each. Patients in both groups were eligible to receive up to three additional doses of surfactant as rescue therapy in the neonatal intensive care unit, if needed.

OUTCOME MEASURES

The primary outcome variable was survival to discharge to home. Secondary variables included neonatal complications and requirement for oxygen therapy at 36 weeks' postmenstrual age.

RESULTS

Among three centers, 651 infants were enrolled and randomized before delivery. Survival to discharge to home was similar for the two strategies for surfactant therapy as prophylaxis: 76% for the immediate bolus group and 80% for the postventilatory aliquot group. In a secondary analysis, the rate of supplemental oxygen administration at 36 weeks' postmenstrual age was 18% for the immediate bolus group and 13% for the postventilatory aliquot group.

CONCLUSIONS

Survival to discharge to home was similar with immediate bolus and postventilatory aliquot strategies for surfactant prophylaxis. Because of its logistical advantages in the delivery room and its beneficial effects on prolonged oxygen requirements, we recommend the postventilatory aliquot strategy for surfactant prophylaxis of premature infants delivered before 29 weeks' gestation.

School-age follow-up of prophylactic versus rescue surfactant trial: pulmonary, neurodevelopmental, and educational outcomes

BACKGROUND

Exogenous surfactant replacement has improved survival and reduced pulmonary complications of prematurity. Improved early outcomes for infants of <30 weeks' gestation treated with a strategy of prophylactic versus rescue surfactant, if needed, were demonstrated in a multicenter, randomized trial conducted between 1985 and 1988. We reevaluated a subset of survivors from this trial to determine the pulmonary and neurodevelopmental outcomes at school age.

METHODS

At 4.5 to 8 years of age, all survivors from one of the three centers were located, and 96% were evaluated. The original randomization included stratification by center and followed an intention-to-treat methodology in assessing the efficacy of prophylactic versus rescue treatment with surfactant. The follow-up test battery included a health-assessment questionnaire, spirometry, 88% saturation test, neurologic examination, and the McCarthy Scales of Children's Abilities (MSCA) and the Conners' Parent Rating Scale-48. Educational achievement was determined by school class placement and teachers' reports of achievement.

RESULTS

Of the 192 children originally enrolled, 154 survived. Evaluations were performed on 148 of these infants. An abnormal pulmonary history was found in 45 (30%) of the children: 16 (22%) in the prophylactic group and 29 (39%) in the rescue group. Formal pulmonary function was evaluated in 81 children; 29 (78%) in the prophylactic group and 33 (75%) in the rescue group were considered abnormal. No significant differences were found between the two groups on either cognitive or motor subscales of the MSCA, the Conners' Parent Rating Scale-48, the neurologic examination, the education services received in school, or the teacher ratings of below-average academic performance. Intelligence scores measured on the MSCA were low-normal for both groups. Some level of educational assistance was being provided to 72 (49%) of the cohort studied, and both groups had below average educational performance and increased needs for educational assistance.

CONCLUSIONS

Prophylactic surfactant administration to infants of <30 weeks' gestation was associated with fewer long-term clinical pulmonary complications than assignment to rescue administration. Formal pulmonary testing at school age did not reveal significant differences between treatment groups in those infants who could be tested. There also were no group differences found on neurologic, cognitive, behavioral, or educational assessments at school age.

Cell-specific expression of fibronectin and EIIIA and EIIIB splice variants after oxygen injury

Cellular fibronectin (cFN) expression is characteristic of injured tissues. Unlike plasma FN, cFN mRNA often contains the EIIIA or EIIIB domains. We examined the lung cell-specific expression of total cFN mRNA and the EIIIA and EIIIB splice variants in rabbits after acute oxygen injury. By in situ hybridization, control lung had low cFN mRNA. After exposure to > 95% oxygen, mRNAs for total cFN and EIIIA were noted primarily in alveolar macrophages and large-vessel endothelial cells. By 3-5 days recovery, cFN and EIIIA mRNA abundance was increased in alveolar septal cells (i.e., alveolar epithelial, interstitial, or endothelial cells) and in some large-vessel endothelial cells but was low in bronchial epithelial cells. During recovery, EIIIB mRNA was low in alveolar septal cells but was noted mainly in chondrocytes. Immunostaining for EIIIA increased during recovery, paralleling the in situ hybridizations. Because FN may modulate alveolar type II cell phenotype, we investigated type II cell cFN mRNA expression in vivo. During recovery, neither isolated type II cells nor cells with surfactant protein C mRNA in vivo contained FN mRNA. In summary, these data suggest that cFN with the EIIIA domain has a role in alveolar cell recovery from oxygen injury and that type II cells do not express cFN during recovery.

Unusual manifestation of a vein of Galen malformation: value of CT angiography

We describe a neonate with aneurysmal dilatation of the vein of Galen with arteriovenous fistulous sites located at the superior vermian vein. Helical CT angiography was useful for evaluating the anomalous vessels.

Differential cytokine mRNA expression by neonatal pulmonary cells

The purpose of this study was to describe cytokine profiles of human neonatal pulmonary cells isolated by tracheal aspiration (TA) and by deep pulmonary lavage (DPL). We hypothesized that mRNA phenotyping, using the technique of reverse transcriptase polymerase chain reaction (RT-PCR), would reveal differences in cytokine expression patterns between cells from proximal and distal airway compartments. We reasoned that cells derived by DPL may reflect pathogenic pathways indicative for the development of bronchopulmonary dysplasia in the premature infant. Here we have described the detection of mRNA for IL-1 alpha, IL-1 beta, IL-6, IL-8, and tumor necrosis factor-alpha. Fourteen paired TA and DPL samples from six premature infants were collected at 1, 7, or 28 d of age. Two of 14 samples were negative for beta-actin (a ubiquitous mRNA) by RT-PCR and were excluded from further analysis. Each of the remaining 12 samples expressed IL-8. Furthermore, each cytokine could be expressed by TA or DPL cells. Cytokine mRNA phenotype profiles were found to differ between TA and DPL cells in four of five paired samples. Our results show that cells retrieved from these two pulmonary compartments are sources for these cytokines and suggest that RT-PCR of TA/DPL cells can be used to test hypothetical predictive markers for the development of bronchopulmonary dysplasia.

Interleukin-8 and monocyte chemoattractant protein-1 mRNAs in oxygen-injured rabbit lung

The chemokines interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) are neutrophil and monocyte attractants, respectively. We hypothesized that IL-8 and MCP-1 mRNA expression in alveolar macrophages (AM) lavaged from rabbit lung would be increased by oxygen exposure, which is known to induce inflammation. Adult rabbits were exposed to > 95% oxygen for up to 64 h and allowed to recover in room air for up to 72 h before killing and pulmonary lavage. Numbers of lavageable polymorphonuclear cells (PMN) and AM rose during the exposure protocol. Quantitative in situ hybridization with 3H-labeled cRNA probes showed both IL-8 and MCP-1 mRNA expression in AM during oxygen exposure, with peak levels of IL-8 mRNA at 56-h oxygen exposure and of MCP-1 mRNA at 64-h oxygen exposure with 24-h room air recovery. IL-8 mRNA was present in PMN between 48-h oxygen exposure and 64-h oxygen exposure with 24-h room air recovery. MCP-1 mRNA was not expressed in PMN. This pattern of chemokine mRNA expression emphasizes the importance of inflammatory cells as effectors in the pulmonary response to oxygen exposure.

Cell-specific expression of fibronectin in adult and developing rabbit lung

Fibronectin (FN), a glycoprotein component of the extracellular matrix, plays a role in tissue morphogenesis and tissue-specific differentiation through its effects on cell adhesion, cell shape, and cytoskeletal organization. Immunohistochemistry has been used to show that during lung development FN deposition changes, yet the cell-specific sites of pulmonary FN synthesis have not been determined. Because cellular FN synthesis is reflected by FN mRNA abundance, we performed in situ hybridizations to identify pulmonary tissue with the capacity to synthesize FN. Both in situ mRNA hybridization and immunohistochemical staining were performed on tissue sections from lungs of adults and late gestation fetal and neonatal rabbits. In adults, FN transcripts and immunostaining were clearly seen in endothelial cells, smooth muscle cells, and chondrocytes. During lung development, FN transcripts were virtually ubiquitous except in airway epithelium. There was a gradual decrease in FN mRNA abundance with advancing fetal age, but low levels of FN mRNA persisted in neonatal and adult lungs. In contrast, parenchymal immunostaining increased throughout fetal development and remained elevated in the newborn. FN immunostaining was lower in adult lung. In all tissues examined, airway epithelial cells contained no FN transcripts above background. However, immunostaining was detected in airway basement membrane zones and on luminal surfaces of some epithelial cells. The lack of FN transcripts in airway epithelial cells suggests that FN synthesis does not normally occur in this cell type and that its associated FN immunostaining is from another source. The colocalization of FN mRNA and protein in pulmonary endothelial cells, smooth muscle cells, and chondrocytes in adults strongly suggests that these cells are sites of FN synthesis.

Transforming growth factor-beta 1 modulates type II cell fibronectin and surfactant protein C expression

Extracellular matrix (ECM) deposition by alveolar type II cells is important for repair of a damaged alveolar epithelium. Transforming growth factor-beta (TGF-beta) is abundant in injured lung and has profound effects on ECM production and cell differentiation. We determined the effects of TGF-beta 1 on type II cell expression of fibronectin and surfactant protein C (SP-C) in vitro. TGF-beta 1 increased the proportion of type II cells with detectable mRNA for fibronectin from 9 to 68%, as demonstrated by in situ hybridization, and increased the fibronectin mRNA levels 10-fold. TGF-beta 1-treated cultures had increased immunostaining for fibronectin and increased secretion of metabolically labeled fibronectin. A decreased proportion of type II cells treated with TGF-beta 1 had detectable mRNA for SP-C, and the abundance of this message per cell decreased to 25% of control values. No effects of TGF-beta 1 were noted on the proportion of cells that contained lamellar bodies, which was 87% in both groups. These data indicate that TGF-beta 1 regulates type II cell fibronectin protein an mRNA levels. In addition, the decreased abundance of SP-C mRNA suggests that TGF-beta 1 may also modulate type II cell differentiation in lung injury.

Marked twin-twin transfusion in the absence of nonimmune hydrops

The precise pathophysiology of development of nonimmune hydrops in either the recipient or donor twin associated with twin-twin transfusion syndrome is not entirely clear. At times the recipient twin may develop nonimmune hydrops, but at other times the donor twin, and infrequently both, may develop this ominous complication. We present an unusual cases of this syndrome in which discordant twins, despite neonatal hematocrit levels of 86 and 21% were both nonhydropic and discuss the possible underlying pathophysiology of this occurrence.

Prevention of central venous catheter-related coagulase-negative staphylococcal sepsis in neonates

A randomized, double-blind, controlled trial was conducted to determine whether vancomycin added to parenteral alimentation solution given via a central venous catheter would decrease the incidence of catheter-related coagulase-negative staphylococcal sepsis. Seventy infants with a central venous catheter (CVC) in place were randomly selected to receive total parenteral nutrition--either the standard solution or a solution containing 25 micrograms of vancomycin per milliliter. Catheter-related sepsis was defined as the isolation of the same bacterial species from specimens of both peripheral and CVC blood with the concentration of bacteria at least tenfold greater in the specimen obtained from the CVC. Specimens from the CVCs were cultured on removal of the catheters to determine colonization. The colonization of catheters by coagulase-negative staphylococci was reduced from 40% to 22% (p = 0.03) in the vancomycin group; catheter-related sepsis was reduced from 15% to no cases (p = 0.004). Fewer infants required CVC reinsertion in the vancomycin-treated group (p = 0.02), who also regained birth weight earlier (13.4 vs 17.1 days (p = 0.014)). Adverse effects of vancomycin infusion were not observed. We conclude that vancomycin added to the solution used for total parenteral nutrition effectively reduces catheter-related sepsis in the neonatal intensive care unit and offers other potential benefits such as the need for fewer catheters and earlier weight gain. However, we do not recommend widespread implementation of this technique until there are data regarding the emergence of vancomycin-resistant organisms.

Two doses of early intravenous dexamethasone for the prevention of bronchopulmonary dysplasia in babies with respiratory distress syndrome

Bronchopulmonary dysplasia is an important complication of ventilation in babies for which treatment with steroids has been advocated. We report the results of a phase I study of early i.v. dexamethasone to prevent the development of bronchopulmonary dysplasia in a high-risk population of ventilated premature babies, < 30 wk gestation, with surfactant-treated respiratory distress syndrome. This study used a limited dexamethasone dosing regimen to minimize toxicity but used administration early in the course of acute lung disease to interrupt the injury cycle. Forty babies were enrolled; 19 were randomized to receive dexamethasone (0.5 mg/kg birth weight at 12-18 h of age and a second dose 12 h later) and 21 were randomized to receive placebo (i.v. saline). The dexamethasone group required less ventilatory support (mean airway, peak inspiratory and end expiratory pressures, and intermittent mandatory ventilation) and supplemental oxygen after study d 4 (all p < 0.05, repeated measures analysis of variance). Improved tidal volume in the dexamethasone group, as measured by pulmonary function testing of infants who remained intubated, was seen on study d 7 (p = 0.02, t test). The dexamethasone group required shorter hospitalizations (median of 95 d versus 106 d, p = 0.01) (proportional hazards regression). Survival in the dexamethasone group was 89% versus 67% in the placebo group (p = 0.08, chi 2 analysis). Survival without bronchopulmonary dysplasia, diagnosed at 36 wk corrected gestational age, was 68% in the dexamethasone group versus 43% in the placebo group (p = 0.14).(ABSTRACT TRUNCATED AT 250 WORDS)

Amnioinfusion during labor complicated by particulate meconium-stained amniotic fluid decreases neonatal morbidity

OBJECTIVE

Our purpose was to evaluate the efficacy of prophylactic amnioinfusion in decreasing neonatal morbidity associated with labor complicated by particulate meconium-stained amniotic fluid and to assess potential complications of this procedure.

STUDY DESIGN

One hundred five laboring pregnant women with particulate (moderate or thick) meconium by subjective clinical analysis were randomly assigned to receive amnioinfusion or to receive standard obstetric care without amnioinfusion. Patients with any antepartum complications, other than the presence of meconium, were excluded from the study. Statistical analyses consisted of the two-tailed and paired Student t tests, Pearson chi 2 test, and Wilcoxon nonparametric test. Significance was set at p < 0.05.

RESULTS

The study included 47 patients in the study group and 58 patients in the control group. A significantly greater proportion of study patients demonstrated decreased meconium concentration between rupture of membranes and delivery (46 of 46 vs 15 of 58, p < 0.001). The relative dilution of meconium consistency by objective analysis was significantly different between the study group and the control group (77.1% decrease vs 9.3% increase, p < 0.001). The proportion of neonates with meconium below the vocal cords was reduced in the study group (two of 47 vs 36 of 58, p < 0.001). Umbilical artery pH was increased in the study group neonates (7.29 +/- 0.01 vs 7.25 +/- 0.009, p < 0.05). The rate of neonatal acidemia was reduced in the study group (4 of 45 vs 12 of 50, p < 0.05). The rate of meconium aspiration syndrome was reduced in the study group (1 of 47 vs 8 of 58, p < 0.05). Maternal and neonatal morbidity rates were similar.

CONCLUSION

Prophylactic amnioinfusion should be considered a possible addition to the intrapartum management of patients with particulate meconium-stained amniotic fluid.

Congenital ichthyosis with restrictive dermopathy and Gaucher disease: a new syndrome with associated prenatal diagnostic and pathology findings

BACKGROUND

Since 1988, three nonrelated fatal cases of congenital ichthyosis associated with Gaucher disease have been described in Australia.

CASE

We present a case of Gaucher disease with congenital ichthyosis and restrictive dermopathy and describe the associated prenatal sonographic findings and pathology of this new syndrome.

CONCLUSION

The unusual association of congenital ichthyosis with lipid storage disease may be suspected prenatally. A high index of suspicion may prove this condition to be more common than previously thought.

Prenatal ultrasonographic diagnosis of intracranial teratoma and massive craniomegaly with associated high-output cardiac failure

Congenital intracranial teratomas are rare and usually fatal. We present prenatal diagnosis of such a case associated with scalp, facial, and body skin edema, hepatomegaly, extramedullary hematopoiesis, polyhydramnios, and a hydropic placenta. These manifestations of high-output cardiac failure were thought to be the result of the large cardiac output required by massive intracranial tumor arteriovenous shunting.

Increased fibronectin mRNA in alveolar macrophages following in vivo hyperoxia

Oxygen-mediated lung injury can stimulate a fibroproliferative response resulting in the alteration of the pulmonary extracellular matrix and subsequent scarring of parenchymal tissue. Fibronectin (FN), a component of the extracellular matrix, appears in increased quantities in fibrotic lung disease. Alveolar macrophages (AMs) are a potential source of this molecule. Using quantitative in situ hybridization, we demonstrated that AMs from rabbits acutely exposed to 100% oxygen (hyperoxia) for up to 64 h have 20-fold greater levels of FN mRNA relative to cells from control animals. When animals were allowed to recover in room air for up to 72 h after maximal oxygen exposure, AM FN mRNA abundance approached baseline levels. Furthermore, in oxygen-exposed animals, the fraction of lavaged cells expressing FN mRNA was increased 10-fold relative to controls. Although there was marked cell-to-cell variation, we conclude that the AM is a potential source of FN in the events leading to hyperoxia-induced pulmonary fibrosis.

Cellular and molecular responses to lung injury in relation to induction of tissue repair and fibrosis

Those factors that determine whether tissue injury is followed by regeneration and repair or irreversible destruction and fibrosis are only now being elucidated. This article examines the lung's response to injury, the prominent role of polypeptide growth factors and cytokines in directing tissue responses, and the effects of injury on cell-specific expression of a number of genes.

Acute intrapartum twin-twin transfusion. A case report

A rare case of acute intrapartum twin-twin transfusion occurred. The well-recognized criteria of long-standing chronic twin-twin transfusion were absent. Although a cesarean section was performed for obstetric reasons, the hyperperfused twin, A, died intrapartum. Twin B, the hypoperfused twin, although liveborn, died neonatally of renal failure attributed to renal cortical necrosis as a sequel to hypotension.

A comparison of surfactant as immediate prophylaxis and as rescue therapy in newborns of less than 30 weeks' gestation

BACKGROUND

Exogenous pulmonary surfactants are administered into the trachea either to prevent respiratory distress syndrome in premature infants or to treat it. In a randomized, multicenter trial, we compared the results of surfactant therapy initiated as prophylaxis with the results of rescue therapy with surfactant.

METHODS

Before birth, 479 infants with an estimated gestational age of less than 30 weeks were randomly assigned to receive surfactant as prophylaxis (n = 235) or rescue therapy (n = 244). The infants in the prophylaxis group received a 90-mg intratracheal dose of an exogenous calf-lung surfactant extract at the time of delivery, whereas the infants in the rescue-therapy group received 90 mg of the surfactant several hours after delivery if the fractional inspiratory oxygen concentration was at least 0.40 or if the mean airway pressure was at least 0.686 kPa (7 cm of water), or both. Infants in both groups received additional doses of surfactant at intervals of 12 to 24 hours if these criteria were met.

RESULTS

The proportion of infants surviving until discharge to their homes was significantly higher in the prophylaxis group than in the rescue-therapy group (88 vs. 80 percent, P = 0.028). This difference was due primarily to the longer survival of very premature infants (less than or equal to 26 weeks' gestation) in the prophylaxis group than in the rescue-therapy group (75 vs. 54 percent, P = 0.006). According to proportional-hazards regression analysis, the distribution of survival times was better for all infants in the prophylaxis group (P = 0.007) and for the subgroup of infants in the prophylaxis group who were delivered at 26 weeks' gestation or earlier (P = 0.0048). Infants in the prophylaxis group who were delivered at 26 weeks' gestation or earlier had a lower incidence of pneumothorax than similar infants in the rescue-therapy group (7 vs. 18 percent, P = 0.03).

CONCLUSIONS

We found a significant advantage to the administration of the initial dose of surfactant as prophylaxis rather than as rescue therapy in very premature infants.

Predicting risk for bronchopulmonary dysplasia: selection criteria for clinical trials

Early identification of neonates in whom bronchopulmonary dysplasia is most likely to develop permits appropriate enrollment into clinical trials testing early intervention therapies for the prevention or treatment of bronchopulmonary dysplasia. Analysis of 160 neonatal intensive care unit survivors to 28 days revealed that supplemental oxygen requirement at 28 days could be predicted by a logistic regression including (1) birth weight, gestational age, 5-minute Apgar score, and peak inspiratory pressure at 12 hours for 12-hour-old neonates and (2) birth weight, gestational age, peak inspiratory pressure at 12 hours, and mean airway pressure at 10 days for 10-day-old neonates. These two regression analyses were applied prospectively to three new data sets totaling 238 neonates to test their predictive ability. Neonates were classified into low-, moderate-, or high-risk groups on the basis of their predicted probability of requiring oxygen supplementation at 28 days; low = probability of less than 25%, moderate = probability of 25% to 75%, and high = probability greater than 75%. Although these populations were demographically distinct from the original group, the regression analyses performed well. The regression analysis for 12 hours of age classified 125 neonates at low risk of whom 9% required supplemental oxygen at 28 days, and the regression analysis for 10 days classified 141 neonates at low risk of whom 7% required supplemental oxygen. The 12-hour regression analysis classified 80 neonates at moderate risk of whom 33% required supplemental oxygen at 28 days and the 10-day regression analysis classified 49 neonates at moderate risk of whom 24% required supplemental oxygen.(ABSTRACT TRUNCATED AT 250 WORDS)

Drug therapy for bronchopulmonary dysplasia

With improved survival of critically ill premature infants, BPD has become an important sequela of neonatal intensive care. A variety of medications are used in the management of BPD. In this article we have attempted to summarize clinical efficacy, pharmacokinetics, and side effects of many of these medications. Longer-term studies on the efficacy of drug therapy are needed and may be facilitated by the development of accurate and reproducible computerized techniques for the measurement of pulmonary mechanics in neonates. Ultimately, new pharmacologic agents or other strategies that will prevent lung injury from hyperoxia and mechanical ventilation or accelerate tissue repair once injury occurs will play a major role in the prevention and treatment of infants with BPD.

The effect of surfactant replacement therapy on conditions associated with respiratory distress syndrome: patent ductus arteriosus, intraventricular hemorrhage, and bronchopulmonary dysplasia

In assessing the current experience with SRT, both considering its effects on respiratory function and on associated problems, there are strong suggestions that this therapy has the potential to have a major impact on the morbidity and mortality of premature infants. The studies to date have not disclosed any serious adverse reactions, and there are strong trends toward improvements in short-term respiratory function and in long-term outcomes. In particular, SRT does not seem to adversely effect cardiopulmonary circulatory status and worsen the effects of the patent ductus arteriosus. There are no adverse effects on intraventricular hemorrhage and some possibility that it may lead to a reduction in hemorrhages. The use of SRT will likely have its biggest effect on reducing the incidence and severity of bronchopulmonary dysplasia.

Exogenous lung surfactant: effect on radiographic appearance in premature infants

At birth, premature infants of 25-29 weeks gestation, at high risk for development of neonatal respiratory distress syndrome (RDS), were given a single dose (90 mg) of calf lung surfactant extract (CLSE) by intratracheal instillation. The frequency and severity of RDS were assessed with use of a simple radiographic scoring system in which pulmonary parenchymal densities and the prominence of the air-bronchogram effect were used as indicators of widespread atelectasis. Radiographs were obtained in surfactant-treated and control infants within the first 90 minutes of life as part of an initial evaluation of their pulmonary status. Subsequent examinations were performed at less than 24 hours and less than 48 hours of age. Radiographic assessment of lung disease compared consistently with coordinated data on oxygen and mean airway pressure requirements of the infants. Both indicated a significantly decreased frequency and severity of RDS in the infants treated with surfactant. The results provide supporting evidence of the effectiveness of exogenous lung surfactant replacement in mitigating RDS in very premature infants.

New strategies for the prevention of bronchopulmonary dysplasia

This article reviews the progress being made into the prevention or arrest of this complex respiratory disease. The key elements in the pathophysiology are reviewed; the current problems in defining, classifying, and predicting the development of this disorder are discussed and potentially useful interventions also are introduced.

Double-blind, randomized trial of a calf lung surfactant extract administered at birth to very premature infants for prevention of respiratory distress syndrome

Organic solvent extraction of surfactant obtained by lavage of calf lungs yields a highly surface-active material. A double blind, randomized clinical trial to determine the effect of this material on respiratory distress syndrome in premature infants was initiated in the Neonatal Intensive Care Unit at the University of Rochester in December 1983. Infants 25 to 29 weeks gestational age were eligible for entry into the trial. At the time of this interim analysis 32 patients had been randomly selected and entered into the trial, 16 surfactant-treated patients and 16 in a control group who received only saline. At birth, intrapulmonary instillation of the calf lung surfactant extract dispersed in saline or saline alone occurred in the delivery room immediately after intubation and prior to ventilation; infants were then ventilated and treated as usual. At 6, 12, 24, 48, and 72 hours after birth, the severity of respiratory distress was categorized as either minimal, intermediate, or severe based on oxygen and mean airway pressure requirements. Differences observed at six hours after birth were of marginal significance, but at 12 and 24 hours the surfactant-treated group had significantly (P less than .01) less severe respiratory distress compared with the control group. Differences between treated and control infants were not statistically significant at 48 and 72 hours after birth. In four surfactant-treated infants the severity of respiratory distress worsened between 24 and 48 hours after birth, suggesting that one dose of surfactant at birth may not be sufficient for some infants.