Lipocalin-2 and calprotectin as stool biomarkers for predicting necrotizing enterocolitis in premature neonates.

BACKGROUND: Necrotizing enterocolitis (NEC) is a major challenge for premature infants in neonatal intensive care units and efforts toward the search for indicators that could be used to predict the development of the disease have given limited results until now. METHODS: In this study, stools from 132 very low birth weight infants were collected daily in the context of a multi-center prospective study aimed at investigating the potential of fecal biomarkers for NEC prediction. Eight infants (~6%) received a stage 3 NEC diagnosis. Their stools collected up to 10 days before diagnosis were included and matched with 14 non-NEC controls and tested by ELISA for the quantitation of eight biomarkers. RESULTS: Biomarkers were evaluated in all available stool samples leading to the identification of lipocalin-2 and calprotectin as the two most reliable predicting markers over the 10-day period prior to NEC development. Pooling the data for each infant confirmed the significance of lipocalin-2 and calprotectin, individually and in combination 1 week in advance of the NEC clinical diagnosis. CONCLUSIONS: The lipocalin-2 and calprotectin tandem represents a significant biomarker signature for predicting NEC development. Although not yet fulfilling the "perfect biomarker" criteria, it represents a first step toward it. IMPACT: Stool biomarkers can be used to predict NEC development in very low birth weight infants more than a week before the diagnosis. LCN2 was identified as a new robust biomarker for predicting NEC development, which used in conjunction with CALPRO, allows the identification of more than half of the cases that will develop NEC in very low birth weight infants. Combining more stool markers with the LCN2/CALPRO tandem such as PGE2 can further improve the algorithm for the prediction of NEC development.

Proteomics Profiling of Stool Samples from Preterm Neonates with SWATH/DIA Mass Spectrometry for Predicting Necrotizing Enterocolitis.

Necrotizing enterocolitis (NEC) is a life-threatening condition for premature infants in neonatal intensive care units. Finding indicators that can predict NEC development before symptoms appear would provide more time to apply targeted interventions. In this study, stools from 132 very-low-birth-weight (VLBW) infants were collected daily in the context of a multi-center prospective study aimed at investigating the potential of fecal biomarkers for NEC prediction using proteomics technology. Eight of the VLBW infants received a stage-3 NEC diagnosis. Stools collected from the NEC infants up to 10 days before their diagnosis were available for seven of them. Their samples were matched with those from seven pairs of non-NEC controls. The samples were processed for liquid chromatography-tandem mass spectrometry analysis using SWATH/DIA acquisition and cross-compatible proteomic software to perform label-free quantification. ROC curve and principal component analyses were used to explore discriminating information and to evaluate candidate protein markers. A series of 36 proteins showed the most efficient capacity with a signature that predicted all seven NEC infants at least a week in advance. Overall, our study demonstrates that multiplexed proteomic signature detection constitutes a promising approach for the early detection of NEC development in premature infants.

Cumulative effect of evidence-based practices on outcomes of preterm infants born at <29 weeks' gestational age.

BACKGROUND: Extremely preterm infants born at <29 weeks' gestational age are at high risk of death or severe neurological injury. Several individual evidence-based practices have been associated with neuroprotection. OBJECTIVE: The objective of the study was to investigate the cumulative effect of 4 evidence-based practices and their association with death and/or severe neurological injury among infants born at <29 weeks' gestational age. STUDY DESIGN: Observational study of infants born at 230-286 weeks gestational age admitted to neonatal intensive care units participating in the Canadian Neonatal Network from 2015 through 2017. We evaluated 4 practices: antenatal corticosteroids, antenatal MgSO4 for neuroprotection, deferred cord clamping ≥30 seconds, and normothermia on admission. The effect of exposure to 1, 2, 3, and all 4 evidence-based practices compared with none on death and/or severe neurological injury was assessed using multivariable logistic regression models adjusted for patient characteristics. RESULTS: Rate of death and/or severe neurological injury was 20% (873 of 4297) and varied based on exposure to evidence-based practices: none, 34% (54 of 157); 1, 27% (171 of 626); 2, 20% (295 of 1448); 3, 18% (263 of 1448); and all 4, 14% (90 of 618). Significantly lower odds of death and/or severe neurological injury were observed with exposure to antenatal corticosteroids (adjusted odds ratio, 0.52, 95% confidence interval, 0.40-0.69) and deferred cord clamping (adjusted odds ratio, 0.81, 95% confidence interval, 0.68-0.96) but not MgSO4 (adjusted odds ratio, 0.88, 95% confidence interval, 0.72-1.08) or normothermia (adjusted odds ratio, 0.96, 95% confidence interval, 0.79-1.16). Infants exposed to ≥2 evidence-based practices had significantly lower odds of death and/or severe neurological injury than those exposed to no evidence-based practices (adjusted odds ratio, 0.61, 95% confidence interval, 0.43-0.88). CONCLUSION: Among infants born at <29 weeks' gestational age, exposure to at least 2 of the evidence-based practices assessed was associated with decreased odds of death and/or severe neurological injury.

Central Line-Associated Blood Stream Infections and Non-Central Line-Associated Blood Stream Infections Surveillance in Canadian Tertiary Care Neonatal Intensive Care Units.

OBJECTIVE: To determine if the reported reduction in hospital-acquired infections is due to reduced central line-associated blood stream infections (CLABSI) or non-CLABSIs. STUDY DESIGN: A retrospective cohort study design was used to describe the change in organism pattern and incidence of hospital-acquired infections (CLABSIs and non-CLABSIs) in neonates <33 weeks of gestation admitted to tertiary neonatal intensive care units in the Canadian Neonatal Network between January 1, 2010, and December 31, 2016. Hospital-acquired infection was diagnosed when a pathogenic organism was isolated from blood or cerebrospinal fluid in a neonate with suspected sepsis. CLABSI was diagnosed when a central venous catheter was present at the time or removed in the 2 days before a hospital-acquired infection diagnosis. Cochran-Armitage and Mann-Kendall trend tests and linear regression models were used for statistical analyses. RESULTS: Of 28 144 eligible neonates from 30 Canadian Neonatal Network neonatal intensive care units, 3306 (11.7%) developed hospital-acquired infections. There was a significant decrease in the rate of hospital-acquired infections (14.2% in 2010 and 9.2% in 2016; P < .01), and the rate of both CLABSIs and non-CLABSIs (P < .01) over the study period concomitant with a significant decrease in the duration of central line use (P = .01). The rates of meningitis also decreased during the study period (1.2% in 2010 and 0.9% in 2016; P < .01). Infections owing to gram-positive cocci significantly decreased, but infections owing to gram-negative organisms remained unchanged. CONCLUSION: Although there was a significant decrease in CLABSIs and non-CLABSIs, hospital-acquired infections in preterm neonates remained high. Infections owing to gram-negative organisms remained unchanged and are a target for future preventative efforts.

Association of Shift-Level Organizational Factors with Nosocomial Infection in the Neonatal Intensive Care Unit.

Objective: To evaluate the association between shift-level organizational data (unit occupancy, nursing overtime ratios [OTRs], and nursing provision ratios [NPRs]) with nosocomial infection (NI) among infants born very preterm in the neonatal intensive care unit (NICU). Study design: This was a multicenter, retrospective cohort study, including 1921 infants 230/7-326/7 weeks of gestation admitted to 3 tertiary-level NICUs in Quebec between 2014 and 2018. Patient characteristics and outcomes (NIs) were obtained from the Canadian Neonatal Network database and linked to administrative data. For each shift, unit occupancy (occupied/total beds), OTR (nursing overtime hours/total nursing hours), and NPR (number of actual/number of recommended nurses) were calculated. Mixed-effect logistic regression models were used to calculate aOR for the association of organizational factors (mean over 3 days) with the risk of NI on the following day for each infant. Results: Rate of NI was 11.5% (220/1921). Overall, median occupancy was 88.7% [IQR 81.0-94.6], OTR 4.4% [IQR 1.5-7.6], and NPR 101.1% [IQR 85.5-125.1]. A greater 3-day mean OTR was associated with greater odds of NI (aOR 1.08, 95% CI 1.02-1.15), a greater 3-day mean NPR was associated lower odds of NI (aOR 0.96, 95% CI 0.95-0.98), and occupancy was not associated with NI (aOR, 0.99, 95% CI 0.96-1.02). These findings were consistent across multiple sensitivity analyses. Conclusions: Nursing overtime and nursing provision are associated with the adjusted odds of NI among infants born very preterm in the NICU. Further interventional research is needed to infer causality.

Effects of vanilla odor on hypoxia-related periodic breathing in premature newborns: A pilot study.

BACKGROUND: Periodic breathing (PB)-related intermittent hypoxia can have long-lasting deleterious consequences in preterm infants. Olfactory stimulation using vanilla odor is beneficial for apnea of prematurity in the first postnatal days/weeks. We aimed to determine for the first time whether vanilla odor can also decrease PB-related intermittent hypoxia. METHOD: This pilot study was a balanced crossover clinical trial including 27 premature infants born between 30 and 33+6 weeks of gestation. We performed 12-h recordings on two nights separated by a 24-h period. All infants were randomly exposed to vanilla odor on the first or second study night. The primary outcome was the desaturation index, defined as the number per hour of pulse oximetry (SpO2) values <90 % for at least 5 s, together with a drop of ≥5 % from the preceding value. Univariate mixed linear models were used for the statistical analysis. RESULTS: Overall, exposure to vanilla odor did not significantly decrease the desaturation index (52 ± 22 events/h [mean ± SD] on the intervention night vs. 57 ± 26, p = 0.2); furthermore, it did not significantly alter any secondary outcome. In a preliminary post hoc subgroup analysis, however, the effect of vanilla odor was statistically significant in infants with a desaturation index of ≥70/h (from 86 ± 12 to 65 ± 23, p = 0.04). CONCLUSION: In this pilot study, vanilla odor overall did not decrease PB-related intermittent hypoxia in infants born at 30-33+6 weeks of gestation, which is when they are close to term. Preliminary results suggesting a beneficial effect in infants with the highest desaturation index, however, justify further studies in the presence of PB-related intermittent hypoxia as well as in infants born more prematurely.

Association of nurse staffing and unit occupancy with mortality and morbidity among very preterm infants: a multicentre study.

OBJECTIVE: In a healthcare system with finite resources, hospital organisational factors may contribute to patient outcomes. We aimed to assess the association of nurse staffing and neonatal intensive care unit (NICU) occupancy with outcomes of preterm infants born <33 weeks' gestation. DESIGN: Retrospective cohort study. SETTING: Four level III NICUs. PATIENTS: Infants born 23-32 weeks' gestation 2015-2018. MAIN OUTCOME MEASURES: Nursing provision ratios (nursing hours worked/recommended nursing hours based on patient acuity categories) and unit occupancy rates were averaged for the first shift, 24 hours and 7 days of admission of each infant. Primary outcome was mortality/morbidity (bronchopulmonary dysplasia, severe neurological injury, retinopathy of prematurity, necrotising enterocolitis and nosocomial infection). ORs for association of exposure with outcomes were estimated using generalised linear mixed models adjusted for confounders. RESULTS: Among 1870 included infants, 823 (44%) had mortality/morbidity. Median nursing provision ratio was 1.03 (IQR 0.89-1.22) and median unit occupancy was 89% (IQR 82-94). In the first 24 hours of admission, higher nursing provision ratio was associated with lower odds of mortality/morbidity (OR 0.93, 95% CI 0.89 to 0.98), and higher unit occupancy was associated with higher odds of mortality/morbidity (OR 1.19, 95% CI 1.04 to 1.36). In causal mediation analysis, nursing provision ratios mediated 47% of the association between occupancy and outcomes. CONCLUSIONS: NICU occupancy is associated with mortality/morbidity among very preterm infants and may reflect lack of adequate resources in periods of high activity. Interventions aimed at reducing occupancy and maintaining adequate resources need to be considered as strategies to improve patient outcomes.

Antimicrobial utilization in very-low-birth-weight infants: association with probiotic use.

OBJECTIVE: To examine the association between probiotic use and antimicrobial utilization. STUDY DESIGN: We retrospectively evaluated very-low-birth-weight (VLBW) infants admitted to tertiary neonatal intensive care units in Canada between 2014 and 2019. Our outcome was antimicrobial utilization rate (AUR) defined as number of days of antimicrobial exposure per 1000 patient-days. RESULT: Of 16,223 eligible infants, 7279 (45%) received probiotics. Probiotic use rate increased from 10% in 2014 to 68% in 2019. The AUR was significantly lower in infants who received probiotics vs those who did not (107 vs 129 per 1000 patient-days, aRR = 0.89, 95% CI [0.81, 0.98]). Among 13,305 infants without culture-proven sepsis or necrotizing enterocolitis ≥Stage 2, 5931 (45%) received probiotics. Median AUR was significantly lower in the probiotic vs the no-probiotic group (78 vs 97 per 1000 patient-days, aRR = 0.85, 95% CI [0.74, 0.97]). CONCLUSION: Probiotic use was associated with a significant reduction in AUR among VLBW infants.

Association of timing of birth with mortality among preterm infants born in Canada.

OBJECTIVE: To assess the association between time of birth and mortality among preterm infants. STUDY DESIGN: Population-based study of infants born 22-36 weeks gestation (GA) in Canada from 2010 to 2015 (n = 173 789). Multivariable logistic regression models assessed associations between timing of birth and mortality. RESULT: Among infants 22-27 weeks GA, evening birth was associated with higher mortality than daytime birth (adjusted odds ratio [AOR] 1.14, 95% CI 1.01-1.29). Among infants 28-32 weeks GA and 33-36 weeks GA, night birth was associated with lower mortality than daytime birth (AOR 0.75, 95% CI 0.59-0.95; AOR 0.78, 95% CI 0.62-0.99, respectively). Sensitivity analysis excluding infants with major congenital anomaly revealed that associations between hour of birth and mortality among infants born 28-32 and 33-36 weeks GA decreased or were not statistically significant. CONCLUSION: Higher mortality among extremely preterm infants during off-peak hours may suggest variations in available resources based on time of day.

Use and timing of surfactant administration: impact on neonatal outcomes in extremely low gestational age infants born in Canadian Neonatal Intensive Care Units.

BACKGROUND: Use, timing and doses of surfactant in preterm infants are variable in practice in modern NICUs. OBJECTIVE: The objective of this study is to explore the association between use and timing of surfactant administration and common neonatal adverse outcomes in preterm infants with gestational age (GA) < 28 weeks. MATERIAL AND METHODS: Neonates admitted to a participating Canadian Neonatal Network NICU between 2013 and 2015 were studied. Infants were divided into three groups based on surfactant administration: none, early (within 30 min of life), and late surfactant (>30 min). The primary outcome was a composite of ≥2 predefined outcomes: bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP) and severe neurological injury (intraventricular hemorrhage or intraventricular hemorrhage (IVH) grade III/IV ± periventricular leukomalacia). RESULTS: Of 2512 eligible neonates, 430 were in the early, and 1228 were in the late surfactant group. There was no difference in the primary outcome (p = .88). There was a slightly lower risk of late onset sepsis [25% versus 29%, adjusted odds ratio (aOR): 0.8; 95% CI: 0.6-0.9] and ROP (12.4 versus 15%, aOR: 0.7; 95% CI: 0.5-0.9) in the early surfactant group. CONCLUSIONS: In preterm neonates, early administration of surfactant within 30 min of life was not associated with an increased risk of the primary composite outcome, but did have decreased rates of late onset sepsis and ROP.

Gene expression profiling in necrotizing enterocolitis reveals pathways common to those reported in Crohn's disease.

BACKGROUND: Necrotizing enterocolitis (NEC) is the most frequent life-threatening gastrointestinal disease experienced by premature infants in neonatal intensive care units. The challenge for neonatologists is to detect early clinical manifestations of NEC. One strategy would be to identify specific markers that could be used as early diagnostic tools to identify preterm infants most at risk of developing NEC or in the event of a diagnostic dilemma of suspected disease. As a first step in this direction, we sought to determine the specific gene expression profile of NEC. METHODS: Deep sequencing (RNA-Seq) was used to establish the gene expression profiles in ileal samples obtained from preterm infants diagnosed with NEC and non-NEC conditions. Data were analyzed with Ingenuity Pathway Analysis and ToppCluster softwares. RESULTS: Data analysis indicated that the most significant functional pathways over-represented in NEC neonates were associated with immune functions, such as altered T and B cell signaling, B cell development, and the role of pattern recognition receptors for bacteria and viruses. Among the genes that were strongly modulated in neonates with NEC, we observed a significant degree of similarity when compared with those reported in Crohn's disease, a chronic inflammatory bowel disease. CONCLUSIONS: Gene expression profile analysis revealed a predominantly altered immune response in the intestine of NEC neonates. Moreover, comparative analysis between NEC and Crohn's disease gene expression repertoires revealed a surprisingly high degree of similarity between these two conditions suggesting a new avenue for identifying NEC biomarkers.

Sleep of preterm neonates under developmental care or regular environmental conditions.

UNLABELLED: Sleep is the main behavioral state of the premature infant. In adult intensive care units, sleep deprivation has been reported as one of the major stressors. Developmental care (DC) aims to decrease stressful events in neonatal intensive care unit and support well-being. AIM: To assess whether DC is accompanied by changes in sleep in preterm neonates. METHODS: A prospective cross-over study included 33 preterm neonates [mean (S.D.): gestational age: 29.3 (1.8) weeks; birth weight: 1245 (336) g]. Polysomnography was performed in two randomly ordered 3-h periods with and without DC. A blinded electrophysiologist analyzed sleep. The total sleep time (TST) was the primary outcome, duration of active (AS), quiet (QS) and indeterminate sleep, and latency before sleep were the secondary outcomes. Non-parametric Wilcoxon tests and ANOVA were used. RESULTS: In DC condition vs. control: TST increased [in minutes, mean (S.E.M.): 156.2 (2.9) vs. 139.2 (4.6), p=0.002], with increase in AS [86.6 (3.7) vs. 77.0 (4.2), p=0.024] and in QS [47.1 (4.1) vs. 36.9 (4.2), p=0.015], and sleeping latency decreased (2.1 (0.7) vs. 10.5 (2.0), p=0.0005]. CONCLUSION: DC promoted sleep in our study. The impact of DC on the neuro-behavioral outcome needs futures studies.

Nasal trauma due to continuous positive airway pressure in neonates.

OBJECTIVE: To evaluate the incidence and severity of nasal trauma secondary to nasal continuous positive airway pressure (nCPAP) in neonates. DESIGN: Prospective observational study. SETTING: Neonatal intensive care unit (NICU) of the University Hospital of Lausanne, Switzerland. PATIENTS: All neonates admitted between January 2002 and December 2007 treated by nCPAP were eligible. METHODS: Patients' noses were monitored during nCPAP. Nasal trauma was reported into three stages: (I) persistent erythema; (II) superficial ulceration; and (III) necrosis. RESULTS: 989 neonates were enrolled. Mean gestational age was 34 weeks (SD 4), mean birth weight 2142 g (SD 840). Nasal trauma was reported in 420 (42.5%) patients and it was of stage I, II and III in 371 (88.3%), 46 (11%) and 3 (0.7%) patients, respectively. Incidence and severity of trauma were inversely correlated with gestational age and birth weight. The risk of nasal trauma was greater in neonates <32 weeks of gestational age (OR 2.48, 95% CI 1.59 to 3.86), weighing <1500 g at birth (OR 2.28, 95% CI 1.43 to 3.64), treated >5 days by nCPAP (OR 5.36, 95% CI 3.82 to 7.52), or staying >14 days in the NICU (OR 1.67, 95% CI 1.22 to 2.28). Most cases of nasal trauma (90%) appeared during the first 6 days of nCPAP. Persistent visible scars were present in two cases. CONCLUSIONS: Nasal trauma is a frequent complication of nCPAP, especially in preterm neonates, but long-term cosmetic sequelae are very rare. This study provides a description of nasal trauma and proposes a simple staging system. This could serve as a basis to develop strategies of prevention and treatment of this iatrogenic event.