Faculty Bibliography

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: 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.

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.

Abstract Objective: Family-centered care (FCC), which includes involving parents in conversations about medical management, is increasingly employed in the neonatal intensive care unit (NICU). Our aim was to determine which care decisions are discussed by neonatologists with families most frequently and the percentage of clinicians influenced by such conversations. Methods: Anonymous web-based survey provided to 2137 neonatologists assessing information sharing and parental involvement. Results: Thousand and two neonatologists responded in which 893 fully completed the surveys. 88% practice FCC. Topics most frequently discussed with parents were blood transfusion, steroids for lung disease and patent ductus arteriosus (PDA) surgery, each being reported and discussed by more than 90% of respondents. Many therapies, including aminoglycoisdes, total parenteral nutrition, and phototherapy, were discussed with parents by far fewer clinicians. Additionally, parents had most influence on clinicians in two categories, blood transfusion and steroids, with more than 70% reporting that their practice was influenced by parental opinion if communicated. For some topics, such as PDA surgery and central line placement, conversations impacted few clinicians. Conclusions: FCC appears to have an impact on NICU clinical decision-making processes, some more than others. Further investigation in this area may provide information on how to best communicate with families and run effective, efficient FCC rounds.

PURPOSE: The splanchnic-cerebral oxygenation ratio (SCOR) is a measurement comparing regional tissue oxygen saturation of splanchnic organs and brain tissue. SCOR has been previously proposed as a marker of clinical conditions associated with gut ischemia. Our goal was to determine SCOR values in healthy neonates in their first and second days of life. METHODS: Prospective observational study measuring SCOR in term neonates in the nursery using near-infrared spectroscopy (NIRS). RESULTS: Forty-five subjects with a mean gestational age of 39.4 +/- 1.3 weeks were included. Mean SCOR on the first day was 0.90 +/- 0.16 and 0.97 +/- 0.16 on the second day, p = 0.02 (n = 45). No correlation was found between SCOR and gestational age; however, we did find a positive correlation between hour of life and SCOR values (r = 0.28, r (2) = 0.08, p < 0.01, two tails); SCOR appears to stabilize by 36 h. CONCLUSIONS: Our findings demonstrate SCOR values in healthy neonates consistent with those previously theorized and help to validate it as a diagnostic measure. In addition, we have demonstrated that SCOR values may normally be lower in infants during their first days of life, and this information may be helpful to clinicians using NIRS as a diagnostic tool.

Objective To determine etiology of neonatal intensive care unit (NICU) admission and acute morbidities in late preterm (LPT) neonates.Methods Neonates admitted at New York University Langone Medical Center's NICU were grouped as follows: period 1: all LPT neonates with gestational age between 340/7 and 366/7 weeks and born between January 2006 and June 2007; period 2: all term neonates born between January 2007 and June 2008. Neonatal and maternal data were collected from both the groups and compared.Results Thirty-three percent of LPT births were admitted to the NICU, compared with 7% of term births (p < 0.05). LPT neonates had an increased incidence of low birth weight, hypoglycemia, hypothermia, and hyperbilirubinemia as an admission diagnosis (p < 0.001). The overall incidence of respiratory distress syndrome (RDS) was 9%, 4%, 3%, 0.7%, 0.2% and 0% in 34-week, 35-week, 36-week, 37-week, 38- to 39-week, and 40-week gestational age neonates (p < 0. 001).There was an increased incidence of RDS and persistent pulmonary hypertension, along with an increased need for surfactant replacement therapy, continuous positive airway pressure, and ventilator support in the LPT group when compared with the term neonates (p < 0.001).Conclusions LPT neonates are at increased risk for hypothermia, hypoglycemia, hyperbilirubinemia, and respiratory morbidity requiring increased respiratory support when compared with term neonates.

BACKGROUND: Premature neonates often receive red blood cell (RBC) transfusions to improve tissue perfusion and oxygen delivery. Clinical and laboratory indicators used to guide transfusion therapy are inadequate to determine physiologic need with high predictability and transfusions frequently do not result in clinical improvement. The splanchnic-cerebral oxygenation ratio (SCOR) provides insight into overall tissue oxygen sufficiency and can be determined using near-infrared spectroscopy (NIRS). Our aim was to assess the usefulness of SCOR as a marker for transfusion need in preterm infants. STUDY DESIGN AND METHODS: This study was a prospective observational pilot study utilizing NIRS to analyze the SCOR in symptomatic anemic premature neonates receiving RBC transfusions and nontransfused asymptomatic premature neonates with similarly low hemoglobin (Hb) levels. Subject clinical status was determined based on frequency of apnea, bradycardia, pulse-oximetry desaturation events, heart rate, respiratory support, and feeding tolerance. We then assessed for any difference between baseline (pretransfusion) SCOR of 1) symptomatic subjects who improved after transfusion, 2) symptomatic subjects who did not improve, and 3) asymptomatic subjects. RESULTS: The study included 52 subjects (34 transfused, 18 asymptomatic): mean birth weight was 1164 g, mean gestational age was 28.6 weeks, and mean Hb level was 9.0 g/dL. Of 34 transfused subjects, 19 improved (56%). Mean baseline SCOR values were lower in neonates who improved with transfusion, 0.61 +/- 0.22, when compared to those without improvement, 0.75 +/- 0.17, and asymptomatic neonates, 0.77 +/- 0.16 (p = 0.03). Infants with a low baseline SCOR (</=0.73) were more likely to improve after transfusion (likelihood ratio, 2.8; 95% confidence interval, 1.1-6.7). CONCLUSION: SCOR may help identify premature infants who will benefit from RBC transfusion