Administering different levels of parenteral phosphate and amino acids did not influence growth in extremely preterm infants

Early high amino-acid intake is associated with hypophosphatemia in preterm infants

OBJECTIVE

To estimate the incidence of hypophosphatemia in preterm infants according to parenteral nutrition received and to evaluate associated risk factors.

DESIGN

A prospective multicenter cohort study included 111 patients ≤ 1250 g (7 NICUs of the NEOCOSUR Network). Two groups were compared according to the amino-acid supply in the first 48 h: aggressive parenteral group ≥ 3 g/kg/day and standard parenteral group: <2.9 g/kg/day. Hypophosphatemia was defined as serum phosphate < 4 mg/dl. A logistic regression analysis was performed to evaluate associated risk factors.

RESULTS

Fifty-eight infants received aggressive parenteral nutrition. The incidence of hypophosphatemia was significantly higher in the aggressive parenteral group (77.5% vs 53.8%, p = 0.009). Hypophosphatemia was independently associated with aggressive parenteral nutrition (aOR 4.16 95% CI 1.54-12.24) and negatively associated with phosphorous intake (aOR 0.92 95% CI 0.87-0.97).

CONCLUSION

Both high amino-acid intake and low phosphorus supply during the first days after birth were independently associated with hypophosphatemia.

Neonatal Refeeding Syndrome and Clinical Outcome in Extremely Low-Birth-Weight Babies: Secondary Cohort Analysis From the ProVIDe Trial

BACKGROUND

Refeeding syndrome (RS) following preterm birth has been linked to high intravenous (IV) protein intake in the presence of low electrolyte supply. In extremely low-birth-weight (ELBW) babies, we aimed to determine the incidence of RS and associations with birth characteristics and clinical outcomes.

METHOD

Prospective cohort study of ELBW ProVIDe Trial participants in 6 New Zealand neonatal intensive care units. RS was defined as serum phosphate < 1.4 mmol.L^-1 and total calcium > 2.8 mmol.L^-1 . Relationships between RS and other factors were explored using 2-sample tests and logistic regression adjusted for sex, gestation, and birth-weight z-score.

RESULTS

Of 338 babies (mean [SD] birth-weight, 780 (134) g, gestational age, 25.9 [1.7] weeks), 68 (20%) had RS. Mortality was greater in babies with RS (32% vs 11%; P < .0001). More small- than appropriate-for-gestational-age babies developed RS (22% vs 8%; P = .001). Growth from birth to 36 weeks' corrected age was not different between babies who did and did not have RS. In logistic regression, the odds of RS decreased by 70% for each 1 mmol per kg^-1 .d^-1 IV phosphate intake (odds ratio [OR], 0.3; CI, 0.1-0.6; P = .002) and increased by 80% for each 1 g.kg^-1 .d^-1 IV protein intake (OR, 1.8; CI, 1.3-2.7; P = .002).

CONCLUSIONS

Neonatal RS is common in this cohort of ELBW babies and is associated with increased morbidity and mortality. Optimizing phosphate and calcium intakes in IV nutrition solutions may reduce RS and its consequences.