Susan E. Denson

Strategies for Prevention of Health Care-Associated Infections in the NICU

Health care–associated infections in the NICU result in increased morbidity and mortality, prolonged lengths of stay, and increased medical costs. Neonates are at high risk of acquiring health care–associated infections because of impaired host-defense mechanisms, limited amounts of protective endogenous flora on skin and mucosal surfaces at time of birth, reduced barrier function of their skin, use of invasive procedures and devices, and frequent exposure to broad-spectrum antibiotic agents. This clinical report reviews management and prevention of health care–associated infections in newborn infants.

Effects of medical risk and socioeconomic status on the rate of change in cognitive and social development for low birth weight children

Using Hierarchical Linear Models (HLM) analysis, this study evaluated the effects of medical risk at birth and socioeconomic status (SES) on the rate of change in cognitive and social development over the first three years of life in premature children with low birth weight (LBW). Children with LBW (n = 79) with both high (HR) (n = 37) and low (LR) (n = 42) medical risk were compared to healthy full-term (FT) (n = 49) children. Children were assessed longitudinally at 6, 12, 24, and 36 months for cognitive development with the Bayley Scales of Infant Development and the McCarthy Scales for Childrens Abilities, and for social initiative and responsiveness with observational measures. The HR LBW group had slower rates of increases in cognitive scores than did the LR LBW and FT groups and showed more deceleration in cognitive development by 36 months of age. Children with LBW, regardless of medical risk, had lower social initiating scores and slower rates of increase in initiating across the first 36 months than did FT children. As predicted, the groups did not show different rates of change for measures of social responsiveness. Higher SES was predictive of better cognitive and social development for all children. The difficulties encountered by children with LR and HR LBW in developing social initiating skills are discussed in relation to the link between learning to take initiative and early executive function skills.

Comparison of three dosing procedures for administration of bovine surfactant to neonates with respiratory distress syndrome

A multicenter, randomized, double-blind, controlled trial compared three beractant (Survanta) administration procedures in the treatment of neonatal respiratory distress syndrome. Infants weighing > or = 600 gm with respiratory distress syndrome who required assisted ventilation were treated within 8 hours of birth with beractant administered intratracheally. Procedure A required administration in two fractional doses after removal of the infant from the ventilator. Procedure B required administration in two fractional doses through a neonatal suction valve and did not require removal of the infant from the ventilator, and procedure C required administration in four fractional doses during removal from the ventilator. Procedure C is the method used in all previous beractant studies. Of the 299 infants enrolled, 103 were randomly assigned to procedure A, 100 to procedure B, and 96 to procedure C. The results indicate no significant differences among the treatment groups in the clinical outcome measures of fractional inspired oxygen, mean airway pressure, and arterial-alveolar ratio of partial pressure of oxygen at 72 hours of life, or in the incidences of air leaks, pulmonary interstitial emphysema, or death through 72 hours of life. There were no significant differences in the lowest heart rates recorded during administration of doses, but there was less oxygen desaturation during administration of dose 1 with procedure B than with procedure A (p = 0.001), and more reflux of beractant after procedure B than after procedure C (p = 0.007). We conclude that the three procedures are equally effective and can be used to administer beractant safely and effectively. Procedure B has the advantage of allowing administration without interrupting mechanical ventilation.

Longitudinal outcome for low birth weight infants: Effects of intraventricular hemorrhage and bronchopulmonary dysplasia

This study addresses the mental and motor development of 78 low birth weight infants (LBW) classified into five groups according to early medical complications: (1) respiratory distress syndrome (RDS); (2) intraventricular hemorrhage (IVH Grades I-II); (3) IVH (Grade III); (4) IVH (Grade IV) with hydrocephalus; and (5) bronchopulmonary dysplasia (BPD) with or without IVH. Each child received an assessment of mental and motor development at 6, 12, 24 and 36 months of age. Results of mental scores revealed clear effects of group and age, but no interaction of group and age. The RDS and IVH (Grades I-III) groups generally had higher scores on indices of mental development than did IVH (Grade IV) and BPD infants with or without IVH. Although most groups had higher mental scores at the older ages, rates of growth were essentially parallel across the five groups. There was some support for differential rates of motor development, with the IVH (Grade IV) group showing acceleration between 24 and 36 months of age while the BPD group continued to show motor delay at 36 months. These results call into question the common practice of correcting psychology test scores of LBW infants for gestational age.

Feeding, Medical Factors, and Developmental Outcome in Premature Infants

This is a prospective, longitudinal study of premature infants investigating whether the length of time needed to reach full enteral feedings (FEF) or full nipple feedings (FNF) is related to medical complications and/or developmental outcome at 24 months corrected age. Premature infants (n=161) from three institutions with birth weights less than 1,600 grams were followed up from birth to 24 months corrected age. The infants were stratified into groups by the severity of medical complications. Bayley Scales of Infant Development were performed at 24 months corrected age. Multiple linear regression was used to analyze the association between feeding milestones, medical complications, and developmental outcomes. Our results show that when controlling for birth weight and gestational age (GA), the severity of respiratory complications was significantly related to reaching FEF (p=0.024) and FNF (p=0.0014). Furthermore, when controlling for the severity of respiratory complications, GA, and socioeconomic status, an increased length of time to FNF was significantly associated with a poorer mental outcome (p=0.0013). We conclude that there is an association between the length of time to reach FNF and mental developmental outcome at 24 months corrected age. Infants who reach full enteral feedings at an earlier age appear to have a better developmental outcome despite their GA and severity of respiratory complications.

Physical growth of low birthweight infants in the first year of life: Impact of maternal behaviors

Physical growth of preterm infants relates to many medical factors, such as birthweight, severity of medical illnesses, and nutritional status. We previously reported that maternal behaviors influence developmental outcomes in low birthweight infants (birthweight < 1600 g); we now hypothesize that maternal behaviors also influence physical somatic growth in low birthweight (LBW) infants. We serially followed 218 mother-infant pairs from birth through 12 months of age. One-hundred thirteen LBW infants were categorized based on severity of early medical complications. Low Risk infants (LR, n = 71) had acute respiratory distress and/or grade 1-2 intraventricular hemorrhage (IVH), or grade 3 IVH without hydrocephalus. High Risk infants (HR, n = 42) had chronic lung disease, grade 3 IVH with hydrocephalus or grade 4 IVH, and/or periventricular leukomalacia. We also studied 105 socioeconomic (SES) matched Full Term (FT) controls. Maternal behaviors were assessed during home visits with global ratings of Warm Sensitivity and Punitiveness. Infant weight was measured at birth and at 38 weeks, 6 months and 12 months corrected gestational age. We examined alternative expressions of weight growth across the three groups by developing the Weight Quotient (WQ), which is the ratio of actual measured weight to the median weight for age. For each infant the regression of the WQ ratio against correct gestational age was analyzed. We used a General Linear Model to compare the relation of the maternal variables to the weight quotients for the three groups. We determined the catch up growth as the slope of each regression. Results indicated that higher levels of maternal Punitiveness were related to slower rates of growth for High Risk (R2 = 0.36), but not Low Risk or Full Term. For maternal Warm Sensitivity (R2 = 0.36), there were significant (P < 0.05) inverse relations with weight gain growth for the Full Term infants. These data suggest that some maternal behaviors are related to the growth of term and premature infants, although the mechanisms through which this occurs is unclear.

Syndrome of inappropriate antidiuretic hormone secretion in neonates with pneumothorax or atelectasis

Nine episodes of the syndrome of inappropriate antidiuretic hormone secretion occurred in five newborn infants following atelectasis or pneumothorax. All infants had pre-existing lung disease and were being treated with positive pressure ventilation. The mean interval between acute atelectasis or pneumothorax and the development of diagnostic hyponatremia, hypo-osmolal serum, hyperosmolal urine, and oliguria was 13.4 hours. Fluid restriction and removal of the triggering event resulted in resolution of the abnormalities within 1.5 to 4 days. Infants who develop atelectasis or pneumothorax should be evaluated for the subsequent occurrence of SIADH; the administration of a water load to them may result in dilutional hyponatremia, for which fluid restriction, not sodium infusion, is the proper therapy.

Patterns of Physical and Neurologic Development in Preterm Children

OBJECTIVE: To evaluate the influence of medical complications, gestational age, gender, ethnicity, and socioeconomic status on the changes in anthropometric measures and severity of neurologic impairment from 6 to 54 months of age in premature and term infants.STUDY DESIGN: This study was a prospective longitudinal study to determine predictors of patterns of growth and neurologic outcome in low-risk (n=137) and high-risk (n=96) preterm infants compared to full-term infants (n=136). Growth modeling analyses were used to evaluate factors that might influence patterns of physical growth and changes in neurologic status.RESULTS: Medical risk level was a predictor of height and head circumference at 30 months and neurologic outcome. Gender was a predictor of weight gain. Medical risk level and gender predicted 13.8% and 32% of the variance in head circumference and neurologic scores, respectively.CONCLUSION: Medical complications after birth and gender are stronger influences than gestational age on patterns of growth and neurologic outcome.

Utilizing a line maintenance team to reduce central-line-associated bloodstream infections in a neonatal intensive care unit.

Objective:To determine the association of a central-line maintenance team on the incidence of central-line-associated bloodstream infections (CLABSIs) in the neonatal intensive care unit (NICU).Study Design:Central line maintenance in the NICU was limited to a line team starting in March 2008. CLABSI rates were determined before (December 2006 to February 2008) and after implementation of the line team ( March 2008 to August 2010) utilizing consistent National Healthcare Safety Network definitions. Rates were calculated by birth weight categories and overall. Data analysis was performed by two-proportion t test using Minitab.Result:Overall CLABSI decreased by 65% after implementation of the line team. Pre intervention, mean overall CLABSI rate was 11.6 /1000, as compared with 4.0/1000 after intervention (P<0.001). Birth-weight-specific CLABSI rates also decreased significantly. Decreased infection rates were sustained over time.Conclusion:A line team provided for standardized, consistent central-line maintenance care leading to a significant, sustained decrease in CLABSI in a NICU.

Prediction of developmental patterns through 40 months from 6- and 12-month neurologic examinations in very low birth weight infants.

This study examines whether neurologic examinations at 6 and 12 months of age can predict developmental patterns in very low birth weight infants and fullterm controls through 40 months of age. We performed neurologic examinations at 6 and 12 months; the Bayley Scales of Infant Development at 6, 12, and 24 months; and the Stanford-Binet and the McCarthy Motor scale at 40 months. The very low birth weight infants were categorized on the basis of socioeconomic status and high or low risk for early medical complications. More abnormal neurologic scores predicted greater deceleration of cognitive development for high-risk infants only. The 12-month neurologic examination predicted the degree of deceleration in motor development. Medical risk was an independent predictor of curvature of the psychomotor development curve. We conclude that neurologic examinations during the 1st year of life might be used with other factors in decisions concerning referrals to early-intervention programs. J Dev Behav Pediatr 18:215–221, 1997.