Sepsis treatment options identified by 10-year study of microbial isolates and antibiotic susceptibility in a level-four neonatal intensive care unit.

AIM: This observational study investigated the microbiology of blood culture-positive sepsis episodes and susceptibility to empiric antibiotics in early-onset sepsis (EOS) and late-onset sepsis (LOS) in a level-four neonatal intensive care unit (NICU) from 2010 to 2019. METHODS: It was based on patient records and data that Oslo University Hospital, Norway, routinely submitted to the Norwegian Neonatal Network database. Clinical data were merged with blood culture results, including antibiotic susceptibility. RESULTS: We studied 5249 infants admitted to the NICU 6321 times and identified 324 positive blood cultures from 287 infants, with 30 EOS and 305 LOS episodes. Frequent causative agents for EOS were group B streptococci (33.3%), Escherichia coli (20.0%) and Staphylococcus aureus (16.7%). All were susceptible to empiric ampicillin and gentamicin. LOS was most frequently caused by coagulase-negative staphylococci (CONS) (73.8%), Staphylococcus aureus (15.7%) and Enterococci (6.9%). CONS, Staphylococcus aureus, Enterococci, Escherichia coli, Klebsiella and Enterobacter represented 91.9% of LOS episodes and were susceptible to vancomycin and cefotaxime (96.1%), vancomycin and gentamicin (97.0%) and cloxacillin and gentamicin (38.1%). CONCLUSION: Empiric treatment with ampicillin and gentamicin was adequate for EOS. Combining vancomycin and gentamicin may be a safer alternative to cefotaxime for LOS, as this reduces exposure to broad-spectrum antibiotics.

Enhanced nutrient supply to very low birth weight infants is associated with higher blood amino acid concentrations and improved growth.

BACKGROUND & AIMS: Customized nutrient supply is vital to ensure optimal growth among very low birth weight infants (birth weight < 1500 g). The supply of amino acids is especially important due to their impact on protein synthesis and growth. The objectives of this study were to evaluate the impact of enhanced nutrition on growth, blood concentrations of amino acids, and explore possible associations between amino acid concentrations and common neonatal morbidities. We hypothesized higher amino acids levels and growth velocity among infants on enhanced nutrient supply. METHODS: This randomized controlled trial was performed in three university neonatal intensive care units in Oslo, Norway. Fifty very low birth weight infants were randomized to a control or intervention group. Within 24 h after birth, infants in the intervention group received enhanced supply of energy, amino acids, lipids, long-chain polyunsaturated fatty acids and vitamin A, whereas the control group received a standard nutrient supply. The intervention continued until 52 weeks postmenstrual age or until a body weight of 5.5 kg was reached. Amino acid analyses were performed at birth, day 3, 5 weeks of age and 5 months corrected age. Detailed information about nutrient intake, morbidities, blood amino acid concentrations and growth velocity were collected from 44 infants (6 infants excluded). High-performance liquid chromatography was used for amino acid analysis. RESULTS: The intervention group (n = 23) received higher supply of proteins, with higher blood concentrations of amino acids measured at 5 weeks of age, and improved growth velocity (mean 17.4 vs 14.3 g/kg/day, p < 0.001) at 36 weeks postmenstrual age, compared to the control group (n = 21). The correlation between concentrations of branched chain amino acids (leucine, isoleucine and valine) and growth was stronger and more positive among infants: a) in the control group (correlation coefficient ≥ 0.68, p ≤ 0.004); b) born with birth weight appropriate for gestational age (correlation coefficient ≥ 0.53, p ≤ 0.009) and c) not diagnosed with septicemia (correlation coefficient ≥ 0.63, p ≤ 0.005). CONCLUSION: Enhanced nutrient supply to very low birth weight infants led to higher blood amino acid concentrations and improved growth. The correlations between amino acid concentrations and growth velocity were weaker in the intervention group as compared to the control group. This could reflect an upper threshold for protein synthesis and growth with our intervention, whereas a potential for further growth with increasing amino acid supply was possible for the control group. CLINICAL TRIAL REGISTRATION NO: NCT01103219.

Improved Visual Perception in Very Low Birth Weight Infants on Enhanced Nutrient Supply.

BACKGROUND: Optimal nutrient supply to very low birth weight (VLBW: BW <1,500 g) infants is important for growth and neurodevelopment. Growth restriction is common among these infants and may be associated with neurocognitive impairments. OBJECTIVES: To compare an enhanced nutrient supply to a routine supply given to VLBW infants and to evaluate the effects on visual perception of global form and motion measured by visual event-related potentials (VERP). METHODS: A total of 50 VLBW infants were randomized to an intervention group that received an increased supply of energy, protein, fat, essential fatty acids, and vitamin A or a control group that received standard nutritional care. At 5 months' corrected age the infants were examined using VERP to investigate the responses to global form and motion. VERP were analysed at the first (f1) and third (f3) harmonics of the stimulus frequency. RESULTS: Data from 31 subjects were eligible for analysis. The motion VERP responses for the f1 and f3 components were stronger in the area near the posterior midline region in the intervention group compared to the controls in the group analyses (p = 0.02 and p = 0.001, respectively). CONCLUSION: The results showed a more consistent response to global motion among infants receiving enhanced nutrition. The intervention may have improved visual perception of global motion.

Enhanced feeding in very-low-birth-weight infants may cause electrolyte disturbances and septicemia--a randomized, controlled trial.

BACKGROUND & AIMS: High supply of protein and energy has been introduced to very-low-birth-weight infants to improve growth and cognitive development. The aim of this study was to compare two different feeding strategies on postnatal growth and clinical outcome during neonatal hospitalization. METHODS: Fifty very-low-birth-weight infants were randomized to either an enhanced or a standard feeding protocol within 24 h after birth. Chi-square and T-tests were applied. RESULTS: First week protein, fat and energy supply was significantly higher in the intervention group compared to the control group (all P < 0.001). After inclusion of 50 patients we observed a higher occurrence of septicemia in the intervention group, 63% vs. 29% (P = 0.02), and no more patients were included. The infants in the intervention group demonstrated improved postnatal growth, but they also disclosed significant electrolyte deviations during the first week of life with hypophosphatemia, hypokalemia and hypercalcemia. First week phosphate nadir was lower in the infants experiencing septicemia (1.23 (0.50) mmol/L) as compared to the infants without (1.61 (0.61) mmol/L) (P = 0.03). CONCLUSION: Our study implies that enhanced feeding may induce electrolyte imbalances in VLBW infants, and that deleterious side effects similar to those seen in refeeding syndrome may occur. ClinicalTrials.gov, number NCT01103219 and the EudraCT number is 2010-020464-38.

Improved cognitive development among preterm infants attributable to early supplementation of human milk with docosahexaenoic acid and arachidonic acid.

OBJECTIVE: The objective of our study was to evaluate the effect of supplementation with docosahexaenoic acid and arachidonic acid for human milk-fed preterm infants. The primary end point was cognitive development at 6 months of age. METHODS: The study was a randomized, double-blind, placebo-controlled study among 141 infants with birth weights of <1500 g. The intervention with 32 mg of docosahexaenoic acid and 31 mg of arachidonic acid per 100 mL of human milk started 1 week after birth and lasted until discharge from the hospital (on average, 9 weeks). Cognitive development was evaluated at 6 months of age by using the Ages and Stages Questionnaire and event-related potentials, a measure of brain correlates related to recognition memory. RESULTS: There was no difference in adverse events or growth between the 2 groups. At the 6-month follow-up evaluation, the intervention group performed better on the problem-solving subscore, compared with the control group (53.4 vs 49.5 points). There was also a nonsignificant higher total score (221 vs 215 points). The event-related potential data revealed that infants in the intervention group had significantly lower responses after the standard image, compared with the control group (8.6 vs 13.2). There was no difference in responses to novel images. CONCLUSIONS: Supplementation with docosahexaenoic acid and arachidonic acid for very preterm infants fed human milk in the early neonatal period was associated with better recognition memory and higher problem-solving scores at 6 months.

Coagulase-negative staphylococcal sepsis in neonates. Association between antibiotic resistance, biofilm formation and the host inflammatory response.

BACKGROUND: Coagulase-negative staphylococci (CoNS) are the most prevalent pathogens causing late onset sepsis in neonates. They are often multiresistant to antibiotics, and the ability to form biofilm is considered their main virulence determinant. METHODS: During a 12-year period, we identified 150 neonates having 164 suspected septic episodes with growth of CoNS in blood culture. We examined the relationship between antibiotic resistance, phenotypic biofilm production and genetic determinants for biofilm formation in different CoNS species and their correlation with neonatal inflammatory response. RESULTS: Eighty-five episodes were classified as true sepsis, and 79 episodes of CoNS growth in blood culture were considered contaminations. Sixty-one percent of Staphylococcus epidermidis isolates produced biofilm compared with 26% of CoNS non-epidermidis (P < 0.001). We observed no difference in phenotypic biofilm production or genetic determinants for biofilm formation between invasive isolates and contaminants. C-reactive protein levels as a marker of inflammatory response were higher in CoNS sepsis caused by methicillin and aminoglycoside resistant versus susceptible isolates (P = 0.031). In contrast, there was a significant association between a lower C-reactive protein response and biofilm-positive isolates (P = 0.018). Antibiotic resistance was significantly correlated with biofilm production in S. epidermidis, but not in other CoNS species. CONCLUSIONS: CoNS sepsis with biofilm-forming strains was associated with a decreased host inflammatory response, potentially limiting the immune system to counteract the infection. The impact of antibiotic resistance and virulence determinants on clinical outcome of neonatal CoNS sepsis warrants additional clinical studies.