Neonatal metabolic acidosis: effect of chloride from normal saline flushes

Comparison Between Sodium Acetate and Sodium Chloride in Parenteral Nutrition for Very Preterm Infants on the Acid-Base Status and Neonatal Outcomes

PURPOSE

To compare between sodium acetate (SA) and sodium chloride (SC) in parenteral nutrition (PN) with associated metabolic acidosis and neonatal morbidities in preterm infants.

METHODS

Preterm infants below 33 weeks gestational age, and with a birth weight under 1,301 g were enrolled and further stratified into two groups: i) <1,000 g, or ii) ≥1,000 g in birth weight. The subjects were randomized to receive PN containing SA or SC within the first day of life. The results of routine blood investigations for the first 6 days of PN were collated, and the neonatal outcomes were recorded upon discharge or demise.

RESULTS

Fifty-two infants entered the study, with 26 in each group: 29 infants had extremely low birth weight (ELBW). There were no significant differences in birth weight, gestation, sex, exposure to chorioamnionitis and antenatal steroids, surfactant doses and duration of mechanical ventilation between groups. The SA group had significantly higher mean pH and base excess (BE) from days 4 to 6 than the SC (mean pH, 7.36 vs. 7.34; mean BE -1.6 vs. -3.5 [p<0.01]), with a two-fold increase in the mean BE among ELBW infants. Significantly fewer on SA required additional bicarbonate (n=4 vs. 13, p=0.01). The rate of bronchopulmonary dysplasia (BPD) was approximately four-fold lower in SA than SC (n=3 vs. 11, p<0.01). No significant differences were observed in necrotizing enterocolitis, patent ductus arteriosus, retinopathy of prematurity, cholestatic jaundice, and mortality between groups.

CONCLUSION

The use of SA in PN was associated with reduced metabolic acidosis and fewer BPD.

Early chloride intake does not parallel that of sodium in extremely-low-birth-weight infants and may impair neonatal outcomes

BACKGROUND AND OBJECTIVE

Accurate data on the optimal chloride (Cl) intake in premature infants are scarce. The aim of the present study was to describe Cl intakes in the first 10 days of life and to assess the relations between high Cl intakes and corrected serum Cl level or markers of severe acidosis in infants <28 weeks' gestation.

METHODS

Retrospective cohort study including all of the infants <28 weeks admitted to the neonatal intensive care unit during a 3-year period and cared for from birth until day 10 or more.

RESULTS

Fifty-six infants were included. Cumulative total Cl intakes reached 9.6 ± 3.7 mmol/kg at day 3 and 49.2 ± 13.5 mmol/kg at day 10. Inadvertent intakes (from intravenous fluids other than parenteral nutrition) represented on average 70% of total Cl intakes in the first 3 days. Difference between Cl and sodium intakes reached 7.8 ± 4.8 mmol/kg at day 10 and mainly originated from parenteral nutrition. By multivariate analysis, cumulative Cl intake >10 mmol/kg during the first 3 days was an independent risk factor of base excess <-10 mmol/L. Cumulative Cl intake >45 mmol/kg during the first 10 days was an independent risk factor of corrected chloremia >115 mmol/L and of base excess <-10 mmol/L.

CONCLUSIONS

Cumulative Cl intake >10 mmol/kg during the first 3 days (ie, 3.3 mmol · kg (-1) · day(-1) on average) and >45 mmol/kg during the first 10 days (ie, 4.5 mmol · kg (-1) · day(-1) on average) may have unwanted metabolic consequences and should be avoided. Imbalance between electrolytes provided by the parenteral nutrition solution need to be detected and corrected.

Chloride Balance in Preterm Infants during the First Week of Life

Objective. To describe the chloride balance in infants born 25-32-week gestation, analyze the association of chloride changes with hydroelectrolytic status and their relationship with perinatal conditions, morbidities, and neurological outcome. Methods. For 7 days after birth, sodium and chloride balance, plasma potassium, phosphate, and total carbon dioxide (tCO(2)) were prospectively determined and strong ion difference (SID) calculated. Three multivariate regression analyses were performed to identify factors associated with high plasma chloride concentration, low SID, and low tCO(2). Results. 107 infants were studied. Plasma chloride concentration was significantly positively associated with plasma sodium concentration. Higher plasma chloride and lower SID were significantly associated with lower plasma tCO(2). Chloride intake was the main independent factor associated with high plasma chloride, low SID, and low plasma tCO(2), with lesser contribution of sodium intake and low gestational age (GA). Also, patent ductus arteriosus and birth weight loss were independent factors affecting plasma chloride and SID. Neither high chloride levels nor low SID were associated to impaired neurological outcome. Conclusions. In preterm infants, chloride balance is influenced by GA and by interrelationship between sodium and chloride intake. High chloride levels are associated with metabolic acidosis but not related to increased risk of impaired neurological outcome.

Parenteral nutrition-related bone disease

Parenteral nutrition (PN)-related bone disease remains a problem in patients of all ages. Understanding of the pathogenesis of PN-related bone disease is complicated by the effect of underlying illnesses, therapeutic interventions, and pre-existing nutrition deficiencies before the initiation of PN therapy. Interrelation of various nutrients, for example, calcium, phosphorus, and vitamin D, in their effects on bone mineralization, demands simultaneous assessment of the role of multiple nutrients and increases the difficulty in defining the role of a single nutrient in the development of bone disease. However, recent reports indicate that there exist a number of factors important in the development of PN-related bone disease and some factors such as increased mineral requirement are unique to growing infants whereas other factors such as aluminum toxicity may be common to both adult and pediatric populations. Nonnutritional factors, including chronic use of potent loop diuretics and altered acid-base status, can affect urine mineral loss, cell metabolism, and bone mineralization, particularly in small, preterm infants. Current evidence indicates that the cause of PN-related bone disease is multifactorial, and the prevention of PN-related bone disease awaits better delineation of the exact sequence of pathogenic events.

Total parenteral nutrition in the pediatric patient

Over the past 50 years, tremendous advances have been made in the management of children who cannot receive enteral nutrition. Challenges for the future include devising techniques to decrease catheter sepsis, particularly in children with a short bowel, who have a disproportionate number of septic episodes, possibly related to bacterial translocation. The delineation of risk factors for cholestasis associated with total parenteral nutrition and refinement of administration of such nutrition in premature neonates to decrease the incidence of this complication, as well as the morbidity of osteopenia, will extend our ability to help these children.