Faculty Bibliography

OBJECTIVES: Antacid medications are frequently administered to preterm infants. These medications can change gastric pH levels and can affect regular gastrointestinal function and gut micro-bacterial flora. We hypothesized that preterm infants exposed to antacid medications are at a greater risk of necrotizing enterocolitis (NEC) and sepsis, and set out to determine any association, as well as to assess the clinical efficacy of these medications. MATERIALS AND METHODS: Retrospective chart review of preterm infants /=Bell stage 2) or culture proven sepsis. RESULTS: The study comprised 65 eligible neonates, 28 in antacid treatment group and 37 in control. The incidence of NEC (21.4% vs. 2.7%, P=0.04) was significantly higher in the antacid group, but these infants tended to be born more prematurely than control subjects. There was a trend toward more culture proven sepsis cases in the antacid group. We found no difference in signs generally associated with neonatal reflux (apnea, bradycardia, and desaturation events) in subjects treated with antacid medications after treatment began. CONCLUSIONS: Treatment of preterm infants with antacid medications is potentially associated with a higher risk of NEC, and possibly sepsis, while appearing to provide little benefit.

Global tissue perfusion and oxygenation are important indicators of physiologic function in humans. The monitoring of splanchnic oximetry through the use of near-infrared spectroscopy (NIRS) is an emerging method used to assess tissue oxygenation status. Splanchnic tissue oxygenation (SrSO2) is thought to be potentially of high value in critically ill patients because gastrointestinal organs can often be the first to suffer ischemic injury. During conditions of hypovolemia, cardiac dysfunction, or decreased oxygen-carrying capacity, blood flow is diverted toward vital organs, such as the brain and the heart at the expense of the splanchnic circulation. While monitoring SrSO2 has great potential benefit, there are limitations to the technology and techniques. SrSO2 has been found to have a relatively high degree of variability that can potentially make it difficult to interpret. In addition, because splanchnic organs only lie near the skin surface in children and infants, and energy from currently available sensors only penetrates a few centimeters deep, it can be difficult to use clinically in a noninvasive manner in adults. Research thus far is showing that splanchnic oximetry holds great promise in the ability to monitor patient oxygenation status and detect disease states in humans, especially in pediatric populations.

OBJECTIVES: Nasal continuous positive airway pressure (NCPAP) is an accepted form of non-invasive ventilation in preterm infants. Few, if any, studies have shown an advantage of one type of NCPAP over another. It has been theorized that bubble-generated NCPAP may be advantageous for the preterm neonate versus traditionally used ventilator-generated NCPAP. The aim of this study was to examine for any short-term differences in physiologic parameters in preterm subjects receiving these two different methods of NCPAP. METHODS: We conducted a randomized, prospective, cross-over pilot study of preterm infants being treated with NCPAP in the neonatal intensive care unit. Subjects were continuously monitored for several physiologic parameters including heart rate, respiratory rate, oxygen saturation, cerebral tissue oxygen saturation and cerebral fractional oxygen extraction using routine neonatal monitors and near-infrared spectroscopy (NIRS) while on 2 h of bubble NCPAP and 2 h of ventilator NCPAP. Subjects were randomized to be monitored while either starting on bubble NCPAP and then switching to ventilator NCPAP or starting on ventilator NCPAP and switching to bubble NCPAP. RESULTS: Eighteen subjects were included. We found no statistically significant difference in any of the physiologic parameters while subjects were receiving bubble NCPAP versus ventilator NCPAP during the monitoring time periods. While on bubble NCPAP, subjects showed a trend toward decreasing respiratory rate and decreasing cerebral fractional oxygen extraction over time, but this did not reach statistical significance. CONCLUSION: There appears to be no difference in immediate physiologic effects between bubble NCPAP and ventilator NCPAP. This does not preclude the possibility of potential long-term differences, but any differences seen would likely be based on mechanisms that take more time to develop. A larger prospective trial is warranted to confirm our findings.

AIM: Inhaled nitric oxide (iNO) is used to treat neonates with hypoxic respiratory failure (HRF). The aim of this study was to determine clinical characteristics and factors associated with non-response to iNO therapy that may assist in clinical management and weaning strategies. METHODS: Retrospective chart review. The study cohort included gestational age >/=34 weeks' infants with acute HRF who received iNO within 7 days of birth. Subjects were stratified as responders or non-responders to iNO. Non-responders were defined as infants with failure to improve their PaO2 >20 mm Hg within 6 h of iNO initiation, need for extracorporeal membrane oxygenation (ECMO), or mortality. Clinical and laboratory characteristics were then compared between groups. RESULTS: Forty four subjects were included. There were 31 responders and 13 non-responders to iNO therapy. Regression analysis showed significant correlation between a non-response to iNO therapy and changes in PaO2 and pH levels. We found for every 10 mm Hg decrease in PaO2 immediate post-iNO therapy there is a 17.5% decrease in the likelihood of responding to iNO (odds ratio [OR] 0.98, P=0.012). Similarly, for every 0.15 point decrease in pH, there is a 16.3% increased chance of not responding to iNO therapy (OR 1.16, P=0.002). The need for pressor support prior to iNO initiation was also found to be associated with a non-response (OR 2. 94, P=0.034). CONCLUSIONS: Hypotension requiring treatment with pressors at the time of iNO therapy, as well as changes in pH and PaO2 after iNO initiation can be used as early clinical predictors to identify patients quickly who may be iNO non-responders.

BACKGROUND:Increasing evidence is demonstrating that infants born early on during the term period are at increased risk of morbidity compared with infants born closer to a complete 40 week gestational pregnancy. The purpose of this study was to compare early term [gestation age (GA): 37-37 6/7 weeks] neonatal outcomes with those of other full term neonatal intensive care unit (NICU) admissions. METHODS:Retrospective chart review of all term infants admitted to the NICU at New York University Langone Medical Center over a 17 month period. Subjects were grouped and analyzed according to their GA at birth: 1) early term infants (GA between 37 0/7 to 37 6/7 weeks) and 2) other term infants (38 0/7 weeks and older). RESULTS:Early term infants were more likely to require NICU care than other term infants [relative risk: 1.42, 95% confidence interval (CI)=1.07-1.88), P=0.01]. In the NICU, they are more likely to manifest respiratory distress syndrome [odds ratio (OR)=5.7, 95% CI=1.6-19.8, P<0.01] and hypoglycemia (OR=4.6, 95% CI=2.0-10.4, P<0.001). In addition, early term neonates were more likely to be born via elective cesarean section than other term neonates (OR=4.1, 95% CI=2.0-8.5, P<0.001). CONCLUSIONS:Being born at early term is associated with increased risk of respiratory disease and hypoglycemia requiring neonatal intensive care. Further efforts directed at decreasing early term deliveries may be warranted.

Objective This study aims to evaluate impact of respiratory and other neonatal comorbidities on neurodevelopmental outcome in late preterm infants (LPT). Method Retrospective study of LPT infants (34 (0/7)-36 (6/7) weeks' gestation) discharged from the New York University Langone Medical Center neonatal intensive care unit, during January 2006 to December 2010 and received follow-up care up to 2 years of age. Neonatal morbidities were correlated with neurodevelopmental outcomes and assessed by performance on the Mullen Scales of Early Learning during three developmental follow-up visits. Results A total of 99 LPT completed neurodevelopmental assessment up to 2 years of age. Infants with diagnosis of moderate-to-severe respiratory distress syndrome showed a significantly lower performance in the visual reception on the second (p < 0.01) and third visit (p = 0.02), as well as lower performance in the receptive language (visit 2, p = 0.02; visit 3, p < 0.01). A diagnosis of persistent pulmonary hypertension was found to be associated with significantly lower performance in the visual reception at all visits (p < 0.01; p = 0.02; p = 0.02) and in the receptive language on the second and third visit (p = 0.03; p = 0.02). Combined respiratory morbidities were also associated with lower developmental scores in fine motor (visit 2, p < 0.01; visit 3, p = 0.04) as well as expressive language (visit 3, p = 0.02). Conclusion LPT with significant respiratory morbidities are at higher risk for long-term developmental delays, mainly affecting cognitive developmental domains.

BACKGROUND: There is increasing evidence indicating an association between red blood cell (RBC) transfusions and necrotising enterocolitis (NEC) in preterm infants, especially late-onset NEC. This phenomenon is referred to as transfusion-related acute gut injury (TRAGI). One theory as to a pathophysiological mechanism is that transfusion may result in an ischemia-reperfusion injury to intestinal tissue. We tested the hypothesis that there is significantly greater variability during transfusion in splanchnic tissue oxygen saturation (SrSO2) than in cerebral tissue oxygen saturation (CrSO2). MATERIALS AND METHODS: This was a prospective, observational study using near-infrared spectroscopy to monitor SrSO2 and CrSO2 in preterm neonates undergoing RBC transfusion for symptomatic anaemia. Mean, standard deviation, highest and lowest SrSO2 and CrSO2 values during each transfusion were determined. The greatest difference in SrSO2 and CrSO2 during each transfusion was calculated, along with the coefficient of variation. RESULTS: We studied 37 subjects. Throughout all transfusions, the mean SrSO2 was 45.6% +/-13.8 and the mean CrSO2 was 65.4% +/-6.9 (p<0.001). The variability of SrSO2 was significantly greater than that of CrSO2. Averaging data from all subjects, the greatest difference in SrSO2 was 43.8% +/-13.4 compared with 23.3% +/-7.6 for CrSO2 (p<0.001). The mean coefficient of variation in all transfusions was 20.5% for SrSO2 and 6.0% for CrSO2 (p<0.001). Increasing post-conceptional age did not affect SrSO2 variability (R2=0.022; p=0.379), whereas CrSO2 variability during transfusion decreased with increasing post-conceptional age (R2=0.209; p=0.004). DISCUSSION: In preterm infants, there is a large degree of tissue oxygenation variability in splanchnic tissue during RBC transfusion and this does not change with increasing maturity. We speculate that these findings, combined with lower average tissue oxygenation, may demonstrate susceptibility of the preterm gut to TRAGI.

NICU patients are among those potentially most vulnerable to the effects of natural or man-made disaster on a medical center. The published data on evacuations of NICU patients in the setting of disaster are sparse. In October of 2012, New York University Langone Medical Center was evacuated during Hurricane Sandy in the setting of a power outage secondary to a coastal surge. In this setting, 21 neonates were safely evacuated from the medical center's NICU to receiving hospitals within New York City in a span of 4.5 hours. Using data recorded during the evacuation and from staff debriefings, we describe the challenges faced and lessons learned during both the power outage and vertical evacuation. From our experience, we identify several elements that are important to the functioning of an NICU in a disaster or to an evacuation that may be incorporated into future NICU-focused disaster planning. These include a clear command structure, backups (personnel, communication, medical information, and equipment), establishing situational awareness, regional coordination, and flexibility as well as special attention to families and to the availability of neonatal transport resources.

Abstract Aims: It remains unclear if mode of delivery can have any impact on the neonatal brain. Our aim was to determine in term newborns any differences based on mode of delivery in either neuronal injury biomarkers, phosphorylated axonal neurofilament heavy chain (pNF-H) and ubiquitin C-terminal hydrolase (UCHL1), or brain oxygenation values, regional cerebral tissue oxygen saturation (CrSO2) and cerebral fractional tissue oxygen extraction (CFOE). Methods: An Institutional Review Board approved prospective observational pilot study of well newborns. Serum pNF-H and UCHL1 levels were measured on the day following delivery. CrSO2 values along with CFOE values were also measured using near-infrared spectroscopy (NIRS) and pulse oximetry. Results: There were 22 subjects, 15 born vaginally and seven born by cesarean section. No difference was found in mean pNF-H (107.9+/-54.3 pg/mL vs. 120.2+/-43.3 pg/mL, P=0.66) or mean UCHL1 (4.0+/-3.5 pg/mL vs. 3.0+/-2.2 pg/mL, P=0.68). No difference was found in mean CrSO2 (80.8+/-5.3% vs. 80.8+/-5.6%, P=0.99) or mean CFOE (0.17+/-0.06 vs. 0.15+/-0.08, P=0.51). Conclusions: We found no difference in neuronal injury markers between term neonates born vaginally compared to those born by cesarean section. From a neurologic standpoint, this supports current obstetric practice guidelines that emphasize vaginal birth as the preferred delivery method whenever possible.

Objective To determine cerebral regional tissue oxygen saturation (CrSO2), renal regional tissue oxygen saturation (RrSO2), and splanchnic regional tissue oxygen saturation (SrSO2) values in healthy term infants.Study Design Near-infrared spectroscopy was used to simultaneously measure CrSO2, RrSO2, and SrSO2 continuously for a 1-hour period on the first and second days of life.Results A total of 41 subjects were monitored out of which complete data were available for 38 subjects. Mean CrSO2 was 78.2 +/- 7.9% on first day; 78.3 +/- 6.1% on second day (p = 0.95). Mean RrSO2 was 92.1 +/- 5.3% on first day; 88.9 +/- 5.9% on second day (p < 0.01). Mean SrSO2 was 69.9 +/- 12.1% on first day and 75.3 +/- 12.4% on second day (p = 0.02).Conclusion There appears to be consistency in rSO2 values in healthy newborns. CrSO2 was similar on both days. Differences observed in RrSO2 and SrSO2 between days may represent a shift in somatic blood flow distribution taking place during the first day of life.