Monitoring technologies in the neonatal intensive care unit: implications for the detection of necrotizing enterocolitis

The Interaction between Stress and Inflammatory Bowel Disease in Pediatric and Adult Patients

Background: Inflammatory bowel diseases (IBDs) have seen an exponential increase in incidence, particularly among pediatric patients. Psychological stress is a significant risk factor influencing the disease course. This review assesses the interaction between stress and disease progression, focusing on articles that quantified inflammatory markers in IBD patients exposed to varying degrees of psychological stress. Methods: A systematic narrative literature review was conducted, focusing on the interaction between IBD and stress among adult and pediatric patients, as well as animal subjects. The research involved searching PubMed, Scopus, Medline, and Cochrane Library databases from 2000 to December 2023. Results: The interplay between the intestinal immunity response, the nervous system, and psychological disorders, known as the gut-brain axis, plays a major role in IBD pathophysiology. Various types of stressors alter gut mucosal integrity through different pathways, increasing gut mucosa permeability and promoting bacterial translocation. A denser microbial load in the gut wall emphasizes cytokine production, worsening the disease course. The risk of developing depression and anxiety is higher in IBD patients compared with the general population, and stress is a significant trigger for inducing acute flares of the disease. Conclusions: Further large studies should be conducted to assess the relationship between stressors, psychological disorders, and their impact on the course of IBD. Clinicians involved in the medical care of IBD patients should aim to implement stress reduction practices in addition to pharmacological therapies.

Utility of Hospital Failure to Rescue for Analyzing Variation in Pediatric Postoperative Mortality

OBJECTIVES

To evaluate the association between pediatric hospital performances in terms of failure to rescue (FTR), defined as postoperative mortality after a surgical complication, and mortality among patients without a surgical complication.

DESIGN

Retrospective cohort study.

SETTING

Forty-eight academic, pediatric hospitals; data obtained from Pediatric Health Information System database (Child Health Corporation of America, Shawnee Mission, KS) (2012-2020).

PATIENTS

Children who underwent at least one of 57 high-risk operations associated with significant postoperative mortality.

EXPOSURES

Hospitals were stratified into quintiles of reliability adjusted FTR (lower than average FTR in quintile 1 [Q1], higher than average FTR in quintile 5 [Q5]). Multivariable hierarchical regression was used to evaluate the association between hospital FTR performance and mortality among patients who did not have a surgical complication.

MEASUREMENTS AND MAIN RESULTS

Among 203,242 children treated across 48 academic hospitals, the complication and overall postoperative mortality rates were 8.8% and 2.3%, respectively. Among patients who had a complication, the FTR rate was 8.8%. Among patients who did not have a complication, the mortality rate was 1.7%. There was a 6.5-fold increase in reliability adjusted FTR between the lowest and highest performing hospitals (lowest FTR hospital-2.7%; 95% CI [1.6-3.9]; highest FTR hospital-17.8% [16.8-18.8]). Complex chronic conditions were highly prevalent across hospitals (Q1, 72.7%; Q2, 73.8%; Q3, 72.2%; Q4, 74.0%; Q5, 74.8%; trend test p < 0.01). Relative to Q1 hospitals, the odds of mortality in the absence of a postoperative complication significantly increased by 33% at Q5 hospitals (odds ratio 1.33; 95% CI [1.07-1.66]). This association was consistent when limited to patients with a complex chronic condition and neonates.

CONCLUSION

FTR may be a useful and valid surgical quality measure for pediatric surgery, even when considering patients without a postoperative complication. These findings suggest practices and processes for preventing FTR at high performing pediatric hospitals might help mitigate the risk of postoperative mortality even in the absence of a postoperative complication.

Characteristics of fecal calprotectin as an early marker for suspected necrotizing enterocolitis in newborns exclusively fed maternal breast milk: a case-control study

Objective

Numerous studies have proposed using fecal calprotectin among many biomarkers associated with necrotizing enterocolitis (NEC) diagnosis. This study aimed to evaluate fecal calprotectin as an early marker for suspected NEC (stage 1) in infants fed exclusively breast milk.

Methods

We collected 20 stool samples from newborns admitted to the neonatal intensive care unit at Aswan University Hospital diagnosed with stage I NEC. We compared them with 20 samples from matched healthy newborns. Fecal calprotectin level was measured by enzyme-linked immunosorbent assay.

Results

Fecal calprotectin level was higher in cases than in the control group (P < 0.001). Also, there was a positive correlation between fecal calprotectin and C-reactive protein in the studied cases (P = 0.001). However, there were no correlations between fecal calprotectin and sex or postnatal age.

Conclusion

Fecal calprotectin levels increase in newborns with stage I NEC. Although not specific, its sensitivity suggests a role as a potential biomarker in the evaluation of suspected NEC.

Diagnostic value of fecal calprotectin in necrotizing enterocolitis: A meta-analysis

BACKGROUND AND OBJECTIVES

Necrotizing enterocolitis is a common gastrointestinal disease in newborns, especially in preterm infants. Our study analyzed the value of fecal calprotectin as a biomarker in the diagnosis of NEC based on previous studies that have confirmed elevated calprotectin levels in NEC patients.

METHOD

We searched several databases including PubMed, Medline, Web of Science and Cochrane Library to identify studies of humans investigating the performance characteristics of fecal calprotectin for the diagnosis of NEC. The quality of included studies was assessed by RevMan5 software (QUADAS-2). The sensitivity, specificity and other measurements of accuracy of fecal calprotectin were pooled using Meta-DiSc software.

RESULT

A total 10 studies with 568 patients included in our meta-analysis. The pooled sensitivity, specificity, diagnostic odds ratio (DOR) and AUC were: 0.86 (95%CI: 0.80-0.91), 0.79 (95%CI: 0.75-0.83), 34.78 (95% CI: 15.30 to 79.07) and 0.92. The pooled sensitivity, specificity, DOR and AUC of subgroup analysis were: 0.85 (95%CI: 0.79-0.90), 0.89 (95%CI: 0.85-0.92), 41.03 (95% CI: 16.87 to 99.78) and 0.92 for nine studies using ELISA; 0.85 (95%CI: 0.79-0.90), 0.89 (95%CI: 0.85-0.92), 42.08 (95% CI: 18.44 to 96.04) and 0.93 for six prospective studies; 0.91 (95%CI: 0.82-0.97), 0.93 (95%CI: 0.88-0.96), 69.51 (95% CI: 17.67 to 273.40) and 0.95 for four studies of preterm infants. 0.86 (95%CI: 0.77-0.92), 0.94 (95%CI: 0.90-0.97), 53.23 (95% CI: 15.68 to 180.73) and 0.94 five studies that defined NEC as stage II or above.

CONCLUSION

Fecal calprotectin is a promising biomarker with high diagnostic value in neonatal, especially in premature infants.

Necrotizing enterocolitis: It's not all in the gut

Necrotizing enterocolitis is the leading cause of death due to gastrointestinal disease in preterm neonates, affecting 5–12% of neonates born at a very-low birth weight. Necrotizing enterocolitis can present with a slow and insidious onset, with some neonates displaying early symptoms such as feeding intolerance. Treatment during the early stages includes bowel rest and careful use of antibiotics, but surgery is required if pneumoperitoneum and intestinal perforation occur. Mortality rates among neonates requiring surgery are estimated to be 20–30%, mandating the development of non-invasive and reliable biomarkers to predict necrotizing enterocolitis before the onset of clinical signs. Such biomarkers would allow at-risk neonates to receive maximal preventative therapies such as careful nutritional consideration, probiotics, and increased skin-to-skin care.

Impact statement

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease; its high mortality rate mandates the development of non-invasive biomarkers to predict NEC before its onset. This review summarizes the pathogenesis, prevention, unresolved issues, and long-term outcomes of NEC.

Thermal imaging applications in neonatal care: a scoping review

Background

In neonatal care, assessment of the temperature of the neonate is essential to confirm on-going health, and as an early signal of potential pathology. However, some methods of temperature assessment involve disturbing the baby, disrupting essential sleep patterns, and interrupting maternal/infant interaction. Thermal imaging is a completely non-invasive and non-contact method of assessing emitted temperature, but it is not a standard method for neonatal thermal monitoring. To examine the potential utility of using thermal imaging in neonatal care, we conducted a comprehensive systematic scoping review of thermal imaging applications in this context.

Methods

We searched EMBASE, MEDLINE and MIDIRS.

Results

From 442 hits, 21 met the inclusion criteria and were included in the review. A significant number (n = 9) were published in the last 8 years. All the studies were observational studies, with 20 out of 21 undertaken in North America or Europe. Most of them had small cohorts (range 4–29 participants). The findings were analysed narratively, to establish the issues identified in the included studies. Five broad themes emerged for future examination. These were: general thermal physiology; heat loss and respiratory monitoring; identification of internal pathologies, including necrotising enterocolitis; other uses of thermal imaging; and technical concerns. The findings suggest that thermal imaging is a reliable and non-invasive method for continuous monitoring of the emitted temperature of the neonates, with potential for contributing to the assurance of wellbeing, and to the diagnosis of pathologies, including internal abnormalities. However, the introduction of thermal imaging into everyday neonatology practice has several methodological challenges, including environmental parameters, especially when infants are placed in incubators or open radiant warmers.

Conclusion

In conclusion, although the first attempt at using thermal imaging in neonatal care started in the early-1970s, with promising results, and subsequent small cohort studies have recently reinforced this potential, there have not been any large prospective studies in this area that examine both the benefits and the barriers to its use in practice.

[Splanchnic oximetry in small for gestational age neonates in relation to prenatal doppler study]

INTRODUCTION

Among small for gestational age neonates, foetal Doppler enables the identification of placental insufficency aetiology and the classification of severity in small for gestational age neonates. There are studies that associate the Doppler data with alterations in the intestinal flow of the newborn, but its relationship with intestinal oximetry has been little studied.

OBJECTIVE

To assess whether there is a relationship between prenatal Doppler data and abdominal oximetry in small for gestational age neonates MATERIAL AND METHODS: A prospective observational study carried out on neonates>32 weeks with a birth weight<P10. The severity of placental insufficiency was classified according to prenatal Doppler criteria. Splanchnic oximetry was monitored during the first three days of life and a comparative analysis of the oximetry data was performed according to the prenatal Doppler alteration severity.

RESULTS

A total of 53 patients were evaluated. Significant differences were observed in the mean regional oximetry (rSO₂) between patients with moderate or severe placental failure and those with normal or slightly altered prenatal Doppler: 42±10 vs. 71.3±10 (P<.001). These differences were maintained during the first 3 days of life. Standard patterns of splanchnic oximetry were identified depending on the degree of placental insufficiency.

CONCLUSIONS

There is a correlation between the foetal Doppler and the splanchnic oximetry pattern during the first days of life. Neonates with moderate or severe placental insufficiency have more altered abdominal oximetry patterns, making it a useful technique to evaluate the degree of placental insufficiency and the risk of oral intolerance in small for gestational age neonates.

Absorption spectra of early stool from preterm infants need to be considered in abdominal NIRS oximetry

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency of the preterm infant. Low abdominal tissue oxygen saturation (StO2) measured by near-infrared spectroscopy (NIRS) oximetry may be an early sign of NEC relevant for treating or even preventing NEC. However, current commercial NIRS oximeters provide inaccurate StO2 readings because they neglect stool as an abdominal absorber. To tackle this problem, we determined the optical properties of faeces of preterm infants to enable a correct abdominal StO2 measurement. In 25 preterm born infants (median age 31 0/7 ± 2 1/7 weeks, weight 1478 ± 511 g), we measured their first five stool probes with a VIS/NIR spectrometer and calculated the optical properties using the Inverse Adding Doubling (IAD) method. We obtained two absorption spectra representing meconium and transitional stool. Probabilistic cluster analysis correctly classified 96 out of 107 stool probes. The faeces spectra need to be considered to enable correct abdominal StO2 measurements with NIRS oximetry.

Electrogastrography, Near-infrared Spectroscopy, and Acoustics to Measure Gastrointestinal Development in Preterm Babies

OBJECTIVES

The aim of the study was to obtain objective measures indicative of gastrointestinal maturity using 3 noninvasive technologies.

METHODS

Electrogastrography (EGG), abdominal near-infrared spectroscopy (NIRS), and bowel sound/acoustics (AC) monitoring were used simultaneously to obtain physiologic measures of the gastrointestinal system of 18 preterm and 5 term neonates who were tolerating enteral feedings. Measures of EGG slow wave voltage (EGG dominant power) and AC signal amplitude (AC dominant power) were obtained after spectral density analysis. Mean abdominal regional saturations (A-rSO2) were obtained directly from NIRS. The relationship of these 3 measures with postmenstrual age (PMA) was assessed.

RESULTS

The results of the 3 methods differed depending on whether the measurements were pre- or postprandial. Postprandial EGG dominant power increases with PMA (r = 0.67, P = 0.003), both pre- and postprandial abdominal NIRS mean regional saturation increase with PMA (r = 0.73, P < 0.001 and r = 0.55, P = 0.009), and postprandial AC dominant power (at 300-500 Hz) increases with PMA (r = -0.48, P = 0.025).

CONCLUSIONS

EGG, abdominal NIRS, and AC, whenever used simultaneously, can provide objective and synergistic measures that correlate with PMA. These findings may be helpful in the assessment of feeding readiness because they reveal quantitative measures suggestive of the developmental process of the gut.

Calprotectin levels in necrotizing enterocolitis: a systematic review of the literature

BACKGROUND

Fecal calprotectin has been extensively investigated as a screening marker for the detection of necrotizing enterocolitis (NEC). However, there is a complete lack of consensus regarding its efficacy as a diagnostic test.

OBJECTIVE

The purpose of the present systematic review is to evaluate the effectiveness of fecal calprotectin as a screening marker for the detection of NEC.

MATERIALS AND METHODS

We conducted a systematic review of studies published in the Medline (1966-2016), Scopus (2004-2016), ClinicalTrials.gov (2008-2016), Cochrane Central Register of Controlled Trials CENTRAL (1999-2016), and Google Scholar (2004-2016) databases, combined with studies found in the reference lists of the included studies. All prospective and retrospective observational cohort studies were included.

RESULTS

Thirteen studies that included 601 neonates were identified in the international literature. The presence and severity of NEC was evaluated with the modified Bell's criteria. Ten studies found significantly elevated fecal calprotectin levels among infants with NEC (p < 0.05). One study found that this effect was observed irrespective of the stage of the disease. Five studies evaluated the efficacy of fecal calprotectin as a diagnostic test. The reported sensitivity ranged between 76 and 100 %, and the specificity varied from 39 to 96.4 %. However, the proposed cut-off values were not similar.

CONCLUSION

Current evidence suggests that fecal calprotectin is elevated in newborns suffering from NEC. However, its significance as an early screening marker remains unknown. Future studies are needed and should focus on the identification of specific cut-off values.

Can Monitoring Fetal Intestinal Inflammation Using Heart Rate Variability Analysis Signal Incipient Necrotizing Enterocolitis of the Neonate?

OBJECTIVE

Necrotizing enterocolitis of the neonate is an acute inflammatory intestinal disease that can cause necrosis and sepsis. Chorioamnionitis is a risk factor of necrotizing enterocolitis. The gut represents the biggest vagus-innervated organ. Vagal activity can be measured via fetal heart rate variability. We hypothesized that fetal heart rate variability can detect fetuses with incipient gut inflammation.

DESIGN

Prospective animal study.

SETTING

University research laboratory.

SUBJECTS

Chronically instrumented near-term fetal sheep (n = 21).

MEASUREMENTS AND MAIN RESULTS

Animals were surgically instrumented with vascular catheters and electrocardiogram to allow manipulation and recording from nonanesthetized animals. In 14 fetal sheep, inflammation was induced with lipopolysaccharide (IV) to mimic chorioamnionitis. Fetal arterial blood samples were drawn at selected time points over 54 hours post lipopolysaccharide for blood gas and cytokines (interleukin-6 and tumor necrosis factor-α enzymelinked immunosorbent assay). Fetal heart rateV was quantified throughout the experiment. The time-matched fetal heart rate variability measures were correlated to the levels of interleukin-6 and tumor necrosis factor-α. Upon necropsy, ionized calcium binding adaptor molecule 1+ (Iba1+), CD11c+ (M1), CD206+ (M2 macrophages), and occludin (leakiness marker) immunofluorescence in the terminal ileum was quantified along with regional Iba1+ signal in the brain (microglia). Interleukin-6 peaked at 3 hours post lipopolysaccharide accompanied by mild cardiovascular signs of sepsis. At 54 hours, we identified an increase in Iba1+ and, specifically, M1 macrophages in the ileum accompanied by increased leakiness, with no change in Iba1 signal in the brain. Preceding this change on tissue level, at 24 hours, a subset of nine fetal heart rate variability measures correlated exclusively to the Iba+ markers of ileal, but not brain, inflammation. An additional fetal heart rate variability measure, mean of the differences of R-R intervals, correlated uniquely to M1 ileum macrophages increasing due to lipopolysaccharide.

CONCLUSIONS

We identified a unique subset of fetal heart rate variability measures reflecting 1.5 days ahead of time the levels of macrophage activation and increased leakiness in terminal ileum. We propose that such subset of fetal heart rate variability measures reflects brain-gut communication via the vagus nerve. Detecting such noninvasively obtainable organ-specific fetal heart rate variability signature of inflammation would alarm neonatologists about neonates at risk of developing necrotizing enterocolitis and sepsis. Clinical validation studies are required.

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.

Physical Activity and Gastric Residuals as Biomarkers for Region-Specific NEC Lesions in Preterm Neonates

BACKGROUND

Necrotizing enterocolitis (NEC) is a serious feeding-related inflammatory gut disease with high mortality. Early clinical markers of NEC are of great importance for optimizing preventive interventions.

OBJECTIVE

Using preterm pigs as models, we hypothesized that an early postnatal onset of NEC can be predicted by decreased physical activity during the first few days after birth.

METHODS

Cesarean-delivered preterm pigs were fed parenteral nutrition and increasing amounts of formula for 5 days after birth (n = 120). Their physical activity was quantified by a continuous camera surveillance system and they were evaluated twice daily for clinical signs of apathy, discoloration, respiratory distress, abdominal distension and diarrhea. The volume of gastric residuals and the presence of macroscopic NEC-like lesions in the stomach, intestine and colon were recorded at euthanasia on day 5.

RESULTS

Half of the pigs (48%) showed clear NEC-like lesions on day 5, and these individuals had more adverse clinical symptoms from day 3 but decreased physical activity already from day 2 relative to the unaffected pigs (both p < 0.05). Only animals with NEC lesions in the small intestine had lower physical activity on days 2 and 3, and the increased volume of gastric residuals was specifically related to colon lesions (both p < 0.05).

CONCLUSIONS

Decreased physical activity precedes the clinical symptoms of NEC in the small intestine of preterm pigs, and increased gastric residuals predict NEC lesions in the colon. Physical activity and gastric residuals may function as clinical biomarkers for region-specific NEC lesions in preterm neonates.

Bolus vs. continuous feeding: effects on splanchnic and cerebral tissue oxygenation in healthy preterm infants

BACKGROUND

Intermittent and continuous tube feeding modes are commonly used to feed preterm infants. However, there is no clear evidence regarding which method is better tolerated. We investigated the differences between bolus and continuous feeding in terms of cerebral and splanchnic oxygenation in healthy preterm infants.

METHODS

Thirty preterm infants underwent a simultaneous 6-h near-infrared-spectroscopy monitoring of cerebral and splanchnic oxygenation, during which they were fed twice through an orogastric tube: one meal was given as a 10-min bolus, and the other was given continuously over a period of 3 h. Oxygenation trends over time were evaluated and compared between bolus and continuous feeding modes.

RESULTS

Cerebral oxygenation did not change over time and did not differ between the two feeding techniques. Splanchnic oxygenation changed significantly over time and differed between the two feeding techniques, with a significant increase after bolus feeding and a remarkable reduction during continuous feeding.

CONCLUSION

Bolus and continuous feeding modes influence splanchnic oxygenation in healthy preterm infants differently. Further studies are needed to investigate possible underlying mechanisms and potential effects on feeding tolerance.

Diminished vagal tone is a predictive biomarker of necrotizing enterocolitis-risk in preterm infants

BACKGROUND

Necrotizing enterocolitis (NEC) is an acute neonatal inflammatory disease which may lead to intestinal necrosis, multisystem failure, and death. Currently, NEC is diagnosed by a combination of laboratory and radiographic tests conducted a posteriori i.e., when NEC is already clinically significant. Given the acute onset and rapid progression of NEC, a non-invasive biomarker that allows early detection of patients at risk is required as a matter of urgency. We evaluated whether the high frequency (HF) component of heart rate variability (HRV), a measure of vagal efferent tonic cholinergic activity may be used as a predictive biomarker for NEC-risk before the onset of clinical disease.

METHODS

In this prospective study, stable preterm (gestational age 28-35 weeks) infants had HRV power spectra analyzed from surface electrocardiogram waveforms taken at rest on day 5-8 of life. We used regression modeling to determine the utility of HF-HRV in predicting NEC.

KEY RESULTS

HF-HRV power was 21.5 ± 2.7 and 3.9 ± 0.81 ms(2) in infants that remained healthy and those that later developed stage 2+ NEC, respectively (p < 0.001). Nine of 70 enrolled infants developed NEC. The ROC discriminated a HF-HRV value of 4.68 ms(2) predictive for developing NEC with a sensitivity and specificity of 89% and 87%, and positive and negative predictive value of 50% and 98%, respectively. With predictive regression modeling, the risk (odds ratio) of developing NEC was 10 per every one SD decrease in HF-HRV.

CONCLUSIONS & INFERENCES

Our preliminary data indicate that HF-HRV may serve as a potential, non-invasive predictive biomarker of NEC-risk in NICU infants.

Abnormal heart rate characteristics before clinical diagnosis of necrotizing enterocolitis

OBJECTIVE

Earlier diagnosis and treatment of necrotizing enterocolitis (NEC) in preterm infants, before clinical deterioration, might improve outcomes. A monitor that measures abnormal heart rate characteristics (HRC) of decreased variability and transient decelerations was developed as an early warning system for sepsis. As NEC shares pathophysiologic features with sepsis, we tested the hypothesis that abnormal HRC occur before clinical diagnosis of NEC.

STUDY DESIGN

Retrospective review of Bells stage II to III NEC cases among infants <34 weeks gestation enrolled in a prospective randomized clinical trial of HRC monitoring at three neonatal intensive care units.

RESULT

Of 97 infants with NEC and HRC data, 33 underwent surgical intervention within 1 week of diagnosis. The baseline HRC index from 1 to 3 days before diagnosis was higher in patients who developed surgical vs medical NEC (2.06±1.98 vs 1.22±1.10, P=0.009). The HRC index increased significantly 16 h before the clinical diagnosis of surgical NEC and 6 h before medical NEC. At the time of clinical diagnosis, the HRC index was higher in patients with surgical vs medical NEC (3.3±2.2 vs 1.9±1.7, P<0.001).

CONCLUSION

Abnormal HRC occur before clinical diagnosis of NEC, suggesting that continuous HRC monitoring may facilitate earlier detection and treatment.