Faculty Bibliography

OBJECTIVE:To assess whether neonatologists show implicit racial and/or socioeconomic biases and whether these are predictive of recommendations at extreme periviability. STUDY DESIGN/METHODS:weeks of gestation asked physicians how likely they were to recommend intensive vs comfort care. Participants were randomized to 1 of 4 versions of the vignette in which racial and socioeconomic stimuli were varied, followed by 2 implicit association tests (IATs). RESULTS:IATs revealed implicit preferences favoring white (mean IAT score = 0.48, P < .001) and greater socioeconomic status (mean IAT score = 0.73, P < .001). Multivariable linear regression analysis showed that physicians with implicit bias toward greater socioeconomic status were more likely than those without bias to recommend comfort care when presented with a patient of high socioeconomic status (P = .037). No significant effect was seen for implicit racial bias. CONCLUSIONS:Building on previous demonstrations of unconscious racial and socioeconomic biases among physicians and their predictive validity, our results suggest that unconscious socioeconomic bias influences recommendations when counseling at the limits of viability. Physicians who display a negative socioeconomic bias are less likely to recommend resuscitation when counseling women of high socioeconomic status. The influence of implicit socioeconomic bias on recommendations at periviability may influence neonatal healthcare disparities and should be explored in future studies.

BACKGROUND:Due to the extremely low incidence of TORCH (toxoplasmosis, rubella, CMV, herpes simplex virus) infections, diagnostic testing of all small for gestational age (SGA) infants aimed at TORCH etiologies may incur unnecessary tests and cost. OBJECTIVE:To determine the frequency of urine CMV PCR and total IgM testing among infants with birth weight <10% and the rate of test positivity. To evaluate the frequency of alternative etiologies of SGA in tested infants. METHODS:Retrospective chart review of SGA infants admitted to the neonatal intensive care unit (NICU) at NYU Langone Medical Center between 2007 and 2012. Subjects were classified as being SGA with or without intrauterine growth restriction (IUGR). The IUGR subjects were then further categorized as having either symmetric or asymmetric IUGR utilizing the Fenton growth chart at birth. Initial testing for TORCH infections, which included serum total IgM, CMV PCR and head ultrasound, were reviewed and analyzed. RESULTS:Three hundred and eighty-six (13%) infants from a total of 2953 NICU admissions had a birth weight ≤10th percentile. Of these, 44% were IUGR; 34% being symmetric IUGR and 10% asymmetric. A total of 32% of SGA infants had urine CMV PCR and total IgM tested with no positive results. As expected, significantly higher percentage of symmetric IUGR infants were tested compared to asymmetric IUGR and non-IUGR SGA infants, (64% vs. 47% vs. 19%) P≤0.01. However, 63% of infants with a known cause for IUGR had same testing done aimed at TORCH infections. We calculated additional charges of $64,065 that were incurred by such testing. CONCLUSIONS:The majority of infants in our study who received testing for urine CMV PCR and total IgM aimed at TORCH infections had one or more other known non-infectious etiologies for IUGR. Because the overall yield of such testing is extremely low, we suggest tests for possible TORCH infections may be limited to symmetric IUGR infants without other known etiologies. Improved guidelines testing for TORCH infections can result in reducing hospital charges and unnecessary studies.

OBJECTIVE: To compare neurally adjusted ventilatory assist and conventional ventilation on patient-ventilator interaction and neural breathing patterns, with a focus on central apnea in preterm infants. DESIGN: Prospective, observational cross-over study of intubated and ventilated newborns. Data were collected while infants were successively ventilated with three different ventilator conditions (30 min each period): 1) synchronized intermittent mandatory ventilation (SIMV) combined with pressure support at the clinically prescribed, SIMV with baseline settings (SIMVBL), 2) neurally adjusted ventilatory assist, 3) same as SIMVBL, but with an adjustment of the inspiratory time of the mandatory breaths (SIMV with adjusted settings [SIMVADJ]) using feedback from the electrical activity of the diaphragm). SETTING: Regional perinatal center neonatal ICU. PATIENTS: Neonates admitted in the neonatal ICU requiring invasive mechanical ventilation. MEASUREMENTS AND MAIN RESULTS: Twenty-three infants were studied, with median (range) gestational age at birth 27 weeks (24-41 wk), birth weight 780 g (490-3,610 g), and 7 days old (1-87 d old). Patient ventilator asynchrony, as quantified by the NeuroSync index, was lower during neurally adjusted ventilatory assist (18.3% +/- 6.3%) compared with SIMVBL (46.5% +/-11.7%; p < 0.05) and SIMVADJ (45.8% +/- 9.4%; p < 0.05). There were no significant differences in neural breathing parameters, or vital signs, except for the end-expiratory electrical activity of the diaphragm, which was lower during neurally adjusted ventilatory assist. Central apnea, defined as a flat electrical activity of the diaphragm more than 5 seconds, was significantly reduced during neurally adjusted ventilatory assist compared with both SIMV periods. These results were comparable for term and preterm infants. CONCLUSIONS: Patient-ventilator interaction appears to be improved with neurally adjusted ventilatory assist. Analysis of the neural breathing pattern revealed a reduction in central apnea during neurally adjusted ventilatory assist use.

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.

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.

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.

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.

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.