Red blood cell transfusions alter splanchnic oxygenation response to enteral feeding in preterm infants: an observational pilot study

Nutritional Strategies for Preterm Neonates and Preterm Neonates Undergoing Surgery: New Insights for Practice and Wrong Beliefs to Uproot

The nutrition of preterm infants remains contaminated by wrong beliefs that reflect inexactitudes and perpetuate old practices. In this narrative review, we report current evidence in preterm neonates and in preterm neonates undergoing surgery. Convictions that necrotizing enterocolitis is reduced by the delay in introducing enteral feeding, a slow advancement in enteral feeds, and the systematic control of residual gastric volumes, should be abandoned. On the contrary, these practices prolong the time to reach full enteral feeding. The length of parenteral nutrition should be as short as possible to reduce the infectious risk. Intrauterine growth restriction, hemodynamic and respiratory instability, and patent ductus arteriosus should be considered in advancing enteral feeds, but they must not translate into prolonged fasting, which can be equally dangerous. Clinicians should also keep in mind the risk of refeeding syndrome in case of high amino acid intake and inadequate electrolyte supply, closely monitoring them. Conversely, when preterm infants undergo surgery, nutritional strategies are still based on retrospective studies and opinions rather than on randomized controlled trials. Finally, this review also highlights how the use of adequately fortified human milk is strongly recommended, as it offers unique benefits for immune and gastrointestinal health and neurodevelopmental outcomes.

Splanchnic-cerebral oxygenation ratio associated with packed red blood cell transfusion in preterm infants

BACKGROUND

Splanchnic-cerebral oxygenation ratio (SCOR), the ratio of splanchnic tissue oxygen (StO₂ s) to simultaneously measured cerebral tissue oxygen (StO₂ c), has been described as a surrogate to detect impaired splanchnic oxygenation associated with hypoperfusion status such as necrotizing enterocolitis. This concept is based on the presumption that any change in SCOR indicates a corresponding change in splanchnic tissue oxygenation as the numerator, whereas cerebral tissue oxygenation as the denominator remains stable. However, it is questionable to utilise this concept to detect splanchnic oxygenation changes in the context of packed red blood cell transfusion (PRBCT).

AIM

The current study examines the contribution of both cerebral and splanchnic oxygenation components to PRBCT-associated SCOR changes in preterm infants.

DESIGN

Prospective cohort study.

SETTING

Neonatal intensive care.

PATIENTS

Hemodynamically stable infants: Gestation <32 weeks; birth weight <1500 g; postmenstrual age <37 weeks: tolerating ≥120 ml/kg/day feed volume.

INTERVENTIONS

PRBCT at 15 ml/kg, over 4 h.

MAIN OUTCOME MEASURES

Transfusion-associated changes were determined by performing mixed models for repeated measures analysis between the 4-h mean pre-transfusion values (SCOR 0, StO₂ s 0, and StO₂ c 0) and the post-transfusion hourly mean values for the next 28 h (SCOR 1-28, StO₂ s 1-28, and StO₂ c 1-28). Dunnett's method was used to adjust for the multiplicity of the p value.

RESULTS

Of 30 enrolled infants 14 [46.7%] male; median [IQR] birth weight, 923 [655-1064] g; gestation, 26.4 [25.5-28.1] weeks; enrolment weight, 1549 [1113-1882] g; and postmenstrual age, 33.6 [32.4-35.0] weeks, one infant was excluded because of corrupted NIRS data. With the commencement of PRBCT, SCOR demonstrated a downward trend throughout the study period. This drift was associated with an increasing StO₂ c trend, while StO₂ s remained unchanged throughout the study period.

CONCLUSIONS AND RELEVANCE

PRBCT-associated SCOR decrease suggests improvement in cerebral oxygenation rather than worsening splanchnic oxygenation. Our study underlines that it is necessary to determine individual components of SCOR, namely cerebral and splanchnic StO₂ to understand SCOR changes in the context of PRBCT.

Framework for feature selection of predicting the diagnosis and prognosis of necrotizing enterocolitis

Neonatal necrotizing enterocolitis (NEC) occurs worldwide and is a major source of neonatal morbidity and mortality. Researchers have developed many methods for predicting NEC diagnosis and prognosis. However, most people use statistical methods to select features, which may ignore the correlation between features. In addition, because they consider a small dimension of characteristics, they neglect some laboratory parameters such as white blood cell count, lymphocyte percentage, and mean platelet volume, which could be potentially influential factors affecting the diagnosis and prognosis of NEC. To address these issues, we include more perinatal, clinical, and laboratory information, including anemia—red blood cell transfusion and feeding strategies, and propose a ridge regression and Q-learning strategy based bee swarm optimization (RQBSO) metaheuristic algorithm for predicting NEC diagnosis and prognosis. Finally, a linear support vector machine (linear SVM), which specializes in classifying high-dimensional features, is used as a classifier. In the NEC diagnostic prediction experiment, the area under the receiver operating characteristic curve (AUROC) of dataset 1 (feeding intolerance + NEC) reaches 94.23%. In the NEC prognostic prediction experiment, the AUROC of dataset 2 (medical NEC + surgical NEC) reaches 91.88%. Additionally, the classification accuracy of the RQBSO algorithm on the NEC dataset is higher than the other feature selection algorithms. Thus, the proposed approach has the potential to identify predictors that contribute to the diagnosis of NEC and stratification of disease severity in a clinical setting.

Feeding Strategies in Preterm Very Low Birth-Weight Infants: State-of-the-Science Review

BACKGROUND

Providing enteral feeds to preterm very low birth-weight (VLBW) infants is critical to optimize nutrition, enhance growth, and reduce complications. Protocols guiding feeding practices can improve outcomes, but significant variation exists between institutions, which may limit their utility. To be most effective, protocols should be based on the best available evidence.

PURPOSE

To examine the state of the science on several key components of feeding protocols for VLBW infants.

SEARCH STRATEGY

The authors searched PubMed, CINAHL, and EMBASE databases for terms related to feeding VLBW infants less than 32 weeks' gestational age, including initiation of feedings, rate of feeding advancement, timing of human milk (HM) fortification, and feeding during blood transfusions, when diagnosed with a patent ductus arteriosus (PDA) and during medical treatment of PDA closure.

RESULTS

Initiation of feeds within the first 3 days of life and advancement by 30 mL/kg/d may decrease time to attain full feeds without increasing complications. Insufficient evidence guides optimal timing of HM fortification, as well as feeding infants undergoing blood transfusions, infants diagnosed with a PDA, and infants receiving medical treatment of PDA closure.

IMPLICATIONS FOR PRACTICE

Integration of existing research regarding feeding initiation and advancement into feeding protocols may improve outcomes. Infants at highest risk of feeding-related complications may benefit from a personalized feeding approach.

IMPLICATIONS FOR RESEARCH

Additional research is needed to provide evidence concerning the optimal timing of HM fortification and feeding strategies for infants undergoing blood transfusions and those diagnosed with a PDA or receiving medical treatment of PDA closure to incorporate into evidence-based feeding protocols.

Cerebral Oxygenation and Autoregulation in Very Preterm Infants Developing IVH During the Transitional Period: A Pilot Study

Background: The transitional period, defined as the first 72 h after preterm birth, is often characterized by a significant hemodynamic instability, which represents an important risk factor for such neurological complications of prematurity as intraventricular hemorrhage (IVH). The impairment of cerebral autoregulation plays a key role in the pathogenesis of IVH, whose incidence is highest during the transitional period. This pilot study aimed to evaluate whether patterns of cerebral autoregulation and oxygenation differ in relation to IVH development in very preterm infants during the transitional period. Methods: Infants <32 weeks' gestation were enrolled within 12 h from birth. A simultaneous monitoring of cerebral oxygenation (CrSO₂) by near-infrared spectroscopy and of heart rate and peripheral oxygen saturation by pulse oximetry was performed over the first 72 h. Cerebral fractional oxygen extraction (cFTOE) and tissue oxygenation-heart rate reactivity index (TOHRx), which represents a marker of cerebrovascular reactivity, were calculated. Daily cranial and cardiac ultrasound scans were performed, in order to assess the hemodynamic status and to detect a possible IVH onset. CrSO₂ and cFTOE, clustered on 6-hour epochs, were compared between infants who developed IVH during the study period and those who did not. A between-group comparison of TOHRx before and after IVH detection was also performed. Results: Twenty preterm infants with a median gestational age of 27 weeks (interquartile range, IQR: 25-30 weeks) and median birth weight of 895 g (IQR: 822-1208 g) were enrolled. Of these, 8 developed IVH. The median age at IVH detection was 40 h (IQR: 30-48 h). Pre-IVH TOHRx was significantly higher compared to matched control periods (p <0.001). CrSO₂ was significantly lower from 12 to 30 h and from 42 h onwards in cases compared to controls; however, a temporary CrSO₂ rise preceded IVH detection. Similarly, cFTOE was significantly higher in IVH infants from 12 to 30 h and from 48 to 72 h, with a transient decrease between the two periods. Conclusions: In preterm infants during the transitional period, the development of IVH is preceded by transient changes in cerebral oxygenation and oxygen extraction which, in turn, may underlie an early impairment of cerebral autoregulation. Larger studies are needed to confirm these preliminary findings.