Craig A. Nankervis

Age‐Dependent Changes in the Postnatal Intestinal Microcirculation

Significant changes occur in intestinal hemodynamics during the transition from fetal to newborn life and then again during the first postnatal month. Most importantly, basal vascular resistance substantially decreases following birth. It then decreases further between postnatal days 1 and 3, plateaus, and then begins a slow, progressive increase between postnatal days 12 and 30. The basal rate of intestinal blood flow mirrors the changes in vascular resistance in an inverse manner. The postnatal changes in vascular resistance appear to be mediated, in large part, by an increase in the constitutive and stimulated production of nitric oxide. Most importantly, the diameter of terminal mesenteric arteries (150–300u2003µm diameter) in newborn (i.e., 1 day old) swine is determined by three intrinsic vascular control systems: endothelial production of nitric oxide and endothelin, and the inherent myogenic response of vascular smooth muscle. In contrast, these vessels in older subjects (i.e., 35 days old) are primarily passive in nature and fail to demonstrate significant diameter change in response to blockade of endogenous nitric oxide production or endothelin receptors, or applied perturbations of pressure or flow rate. The circulatory physiology of the perinatal and newborn intestine is exceptional when compared to the adult condition inasmuch as several hemodynamic variables change quite dramatically between fetal and neonatal life and during the first postnatal month. The unique hemodynamic conditions that characterize the perinatal and newborn intestine appear to be part of the overall physiological transition that occurs as the fetus, once born, replaces the placenta with his gastrointestinal tract to obtain nutrition. The goal of this review is to describe the circulatory physiology of the perinatal and newborn intestine, with a particular emphasis on those portions of the intestinal microcirculation that have thus far been studied. First, however, it is important to discuss the age‐dependent changes that occur within the intestinal circulation during perinatal and early newborn life.

Deliberate Practice Improves Pediatric Residents’ Skills and Team Behaviors During Simulated Neonatal Resuscitation

Objective. To evaluate the skills and team behavior of pediatric residents during resuscitation with a high-fidelity mannequin before and after a deliberate practice intervention. Methods. Each month residents participate in two 90-minute videorecorded sessions (2-3 weeks apart) in an “off-site” delivery room during their neonatal ICU rotation. Teams responded to a scenario that required 5 skills (positive pressure ventilation, chest compressions, endotracheal intubation, umbilical vein catheterization, and epinephrine administration). Skills were scored for technique and timeliness and team behaviors for communication, management, and leadership. A 2-hour focused intervention was given between sessions. Results. In all, 33 residents (11 teams) completed the sessions. Gaps in procedural skills noted during the first session were corrected. Timeliness for completion of skills remained below expectations. Improvements in team behaviors were noted. Conclusions. Deliberate practice improved procedural skills and team performance. Lack of improvement in timeliness suggests that a different educational paradigm is required.

Probiotics and Prebiotics for the Prevention of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) continues to be a major cause of morbidity and mortality in premature infants. Although the pathogenesis of NEC remains unclear, abnormal bacterial colonization has been postulated as playing a central role. Various factors impact bacterial colonization following delivery. Compared to term infants, the bacterial colonization pattern in prematurely born infants is markedly different, with a greater predilection for colonization with pathogenic bacteria. Probiotic and prebiotic administration offers the opportunity to manipulate the intestinal bacterial environment, favoring the growth of commensal bacteria. Experimental data from animal studies and data from human trials suggest that probiotics decrease the incidence of NEC. These preliminary studies support the need for a large, randomized, controlled trial to further investigate the role of probiotics in the prevention of NEC.

Breast-feeding Initiation in Women With Pregestational Diabetes Mellitus

Objective. To examine feeding practices and factors associated with breast-feeding initiation (BFI) in women with pregestational diabetes mellitus (PGDM) and their infants. Methods. In all, 392 PGDM (135 late preterm and 257 term) pregnancies were studied. Infant feeding preference was ascertained on admission. Results. After birth, 166 (42%) of the infants received well-baby care, whereas 226 (58%) were admitted to the newborn intensive care unit (NICU). Hypoglycemia (blood glucose <40 mg/dL), which occurred in 128 (33%) of all infants, did not influence BFI. Of 257 women who intended to BF, 55% initiated BF. Also, 5% of 105 women who intended to feed formula and 13% of the 30 undecided later initiated BF. Conclusions. The BFI rate for women with PGDM is remarkably low even among those who intended to BF. Factors associated with BFI failure in this population were primiparity, African American race, lower education, smoking, lack of intention to BF, and NICU admission.

Breastfeeding initiation in women with gestational diabetes mellitus

BACKGROUNDnIn the United States, breastfeeding initiation (BFI) is reported for 75% of all live births; however, little information is available regarding mothers affected by gestational diabetes mellitus (GDM).nnnOBJECTIVEnTo examine feeding practices and factors associated with BFI in women with GDM and their infants.nnnMETHODSnA total of 303 GDM (58 late preterm and 245 term) pregnancies were studied. Infant feeding preference was ascertained on admission to labor and delivery. Variables known to influence BFI including maternal age, smoking, obesity, racial and educational characteristics were assessed.nnnRESULTSnOn admission 188 women intended to BF, 60 intended to feed formula and 55 were undecided. None of the women who wished to feed formula and 27% of the originally undecided later initiated BF. Regardless of feeding preference 163 (54%) of all mothers initiated BF. Similar BFI rates were found for 176 Class A1 and 127 class A2 women. Logistic regression analysis showed that intention to BF was the most significant predictor of BFI. Factors associated with BFI failure included African American race, lower education, smoking, obesity and admission to NICU. Following delivery 264 (87%) infants received well baby care while 39 (13%) were admitted to the NICU. Among 188 women who intended to BF, BFI involved 81% of 160 infants receiving well baby care and 61% of the 28 admitted to the NICU.nnnCONCLUSIONSnMore than half of women with GDM, who intended to BF, initiated BF. BFI failure remains associated with race, lower education level, smoking, obesity, preference for formula feeding and admission to NICU.

Neonatal outcomes of macrosomic infants of diabetic and non-diabetic mothers

OBJECTIVEnTo compare neonatal outcomes (including breastfeeding (BF) initiation) of 170 macrosomic IDM with that of 739 macrosomic nIDM.nnnDESIGN/METHODSnRetrospective cohort investigation of all macrosomic infants born consecutively over a four-year period (2008-2011). Macrosomic (birth weight ≥4000u200ag) IDM included 100 infants whose mothers had gestational diabetes and 70 whose mothers had pregestational diabetes.nnnRESULTSnIDM were more likely to be delivered by cesarean to obese women while nIDM were more likely to be delivered vaginally to younger women with a higher level of education. Ethnic distribution (60% white, 20% black, 10% Hispanic and 10% Asian or African) was similar in each group. Forty-nine percent of IDM and 7% of nIDM required NICU admission. Respiratory disorders (mainly TTNB) affected 21% of IDM and 3% of nIDM while hypoglycemia was observed in 36% of IDM and 15% of nIDM. Of the 35 IDM delivered vaginally, 10 were complicated by shoulder dystocia without injury. Conversely, 70 of the 458 nIDM delivered vaginally experienced shoulder dystocia that resulted in 6 limb fractures and 3 brachial plexus injuries. On arrival to labor and delivery, 75% of all women intended to BF; however, at the time of discharge, 65% of women with diabetes and 92% of those without diabetes who intended to BF had initiated BF.nnnCONCLUSIONSnBoth macrosomic IDM and macrosomic nIDM are at risk for significant morbidities. Macrosomic IDM carry a higher risk for NICU admissions, leading to maternal-infant separation, and lower BF initiation rates.

Failure to initiate breastfeeding among high risk obstetrical patients who intended to breastfeed

BACKGROUNDnIn the US, at the time of discharge from the hospital, 79% of women had initiated breastfeeding. Intention to breastfeed is a strong predictor of breastfeeding initiation; however, we reported initiation failure in 45% of women with pregestational diabetes who intended to breastfeed. Information regarding intention and initiation among women with other high risk obstetrical conditions (HROB) remains scarce.nnnOBJECTIVEnTo ascertain demographic and clinical factors associated with breastfeeding initiation failure among women with HROB conditions who intended to breastfeed.nnnMETHODSnThe study population is comprised of 89 women with diabetes (DM), 57 who were receiving treatment for substance abuse (SA), 51 women diagnosed with miscellaneous (MISC) conditions and 32 with history of preterm labor/delivery (PTL/D). Intention to exclusively breastfeed or in combination with formula (breastfed/FF) was ascertained prenatally. Breastfeeding was considered initiated if at discharge ≥50% of their infant feedings were maternal milk. Statistics include chi-square, Wilcoxons and logistic regression (pu200a<u200a0.05).nnnRESULTSnOf all women, 59% initiated any breastfeeding. Intention to breastfeed/FF, lack of mother-infant contact during the first hour following birth and limited lactation consultation were predictive of initiation failure. The odds of initiation failure were 2.3 times higher among women who wished to breastfeed/FF as compared to those who wished to exclusively breastfeed. Women from the SA group had lower rates of initiation failure than the other three HROB groups.nnnCONCLUSIONnIntention to breastfeed among women with diverse HROB conditions is similar to that of the general population; however, initiation rates are disappointingly low. Intention to exclusively breastfeed results in fewer initiation failures. Prenatal intention to combine breast and formula feeding characterize women who may benefit from specific educational programs.

Delivery room triage of large for gestational age infants of diabetic mothers

Objective: To review our 4-year experience (2008–2011) with delivery room triage of large for gestational age infants of diabetic mothers. Design/Methods: Retrospective cohort investigation of 311 large for gestational age infants of diabetic mothers (White’s Class A1 (77), A2 (87), B (77), and C-R (70)). Results: Of 311 women, 31% delivered at 34–36 weeks gestational age and 69% at term. While 70% were delivered by cesarean, 30% were vaginal deliveries. A total of 160 asymptomatic infants were triaged from the delivery room to the well baby nursery. Of these, 55 (34%) developed hypoglycemia. In 43 cases, the hypoglycemia was corrected by early feedings; in the remaining 12, intravenous dextrose treatment was required. A total of 151 infants were triaged from the delivery room to the neonatal intensive care unit. Admission diagnoses included respiratory distress (51%), prevention of hypoglycemia (27%), prematurity (21%), and asphyxia (1%). Hypoglycemia affected 66 (44%) of all neonatal intensive care unit infants. Conclusion: Safe triage of asymptomatic large for gestational age infants of diabetic mothers from the delivery room to well baby nursery can be accomplished in the majority of cases. Those infants in need of specialized care can be accurately identified and effectively treated in the neonatal intensive care unit setting.

An improved method to determine orogastric tube insertion length in extremely low birth weight infants

Background: Traditionally, orogastric tube (OGt) insertion length is determined by nose-earlobe-xyphoid (NEX) measurement. Minimum insertion lengths have been proposed for prematures but not for extremely low birth weight (ELBW)

Role of Oxidative Stress in Necrotizing Enterocolitis: Advances and Possibilities for Future Therapy

During normal fetal development, a balance between the production of oxidants and the antioxidant defense systems is critical for proper growth and development. Studies have shown that an imbalance between oxidant production and antioxidant defense mechanisms may lead to preterm birth, fetal growth restriction, and related morbidities. Premature infants are highly susceptible to oxidant-induced damage due to immature antioxidant defense systems or deficiency of antioxidants. As a result there is an increased risk for the development of oxidant-induced diseases of the newborn, such as bronchopulmonary dysplasia, retinopathy of prematurity, and periventricular leukomalacia.