291 - Prevention of Neonatal Refeeding Syndrome with Implementation of a Novel Parenteral Nutrition Regimen

Poster Number: 291
Publication Number: 291.120

Jennifer J. Cerdena, St. Joseph Medical Center, Tacoma, WA, United States; Victoria Oyewole, UC Davis Medical Center, Sacramento, CA, United States; Stephen E. Welty, University of Washington School of Medicine, Tacoma, WA, United States; Gregory C. Valentine, University of Washington, Tacoma, WA, United States

Background: Intrauterine growth restriction (IUGR) affects approximately 10-15% of pregnant women and is the second leading cause of perinatal mortality, just after prematurity. IUGR neonates, believed to have been nutritionally deprived in utero, commonly exhibit electrolyte perturbations associated with refeeding syndrome (RFS) (i.e. hypophosphatemia and hypomagnesemia).

Objective: We evaluated if adding thiamine and standardizing a 1:1 calcium-to-phosphorus ratio in a novel total parenteral nutrition (TPN) for patients with small-for-gestational-age (SGA) or IUGR diagnosis would decrease the incidence of neonatal RFS commonly evident by hypophosphatemia.

Design/Methods: We performed a prospective, interventional, nonrandomized, quality improvement study from October 18, 2018 to May 31, 2019 with comparison to historical cohort (January 1, 2016 through September 31, 2018) at a single center, St. Joseph Medical Center, in Tacoma, Washington. A customized IUGR TPN containing a 1:1 calcium to phosphorus ratio and thiamine was implemented during a 5-month intervention period to identify the incidence of neonatal RFS compared to historic controls. The primary endpoint was prevention of severe hypophosphatemia ( < 2.5 mg/dL). Students t-test was performed to assess differences in means.

Results: A total of 94 patients met the diagnosis of either SGA or IUGR and included in the study (81 during the 2-year pre-intervention period and 13 during the 5-month intervention period). The incidence of severe hypophosphatemia within the first 24 hours after birth was 8.6% (7/81) in pre-intervention compared to 0% (0/13) in the post-intervention cohort, and the mean serum phosphorus was significantly higher after intervention (4.4 ± 1.3 mg/dL vs 5.2 ± 0.99 mg/dL, p=0.028; Figure 1). The mean calcium value in the first 24 hours slightly decreased after intervention (9.20 ± 0.68 mg/dL vs 8.80 ± 0.49 mg/dL, p=0.02; Figure 2).Conclusion(s): With the introduction of thiamine supplementation and 1:1 calcium-to-phosphorus ratio beginning on the day of birth, no incidence of severe hypophosphatemia occurred. Additionally, there was less variability of serum phosphorus levels, significantly higher mean serum phosphorus levels, and less hypercalcemia post-intervention. This quality improvement study shows that thiamine and standardization of phosphorus and calcium in equal proportions in TPN helps adjudicate the common RFS electrolyte disturbances seen in SGA or IUGR neonates.
Figure 1: Serum Phosphorus LevelsProcess control chart demonstrating the changes occurring in serum phosphorus level within the first 24 hours by infant. From the mean, the UCL and LCL are +/- 3 SDs. LCL, lower control limit; UCL, upper control limit. Dashed line represents serum phosphorus level of 2.5 mEq/dL. Yellow circles highlight values that are considered severe hypophosphatemia as defined as < 2.5 mEq/dL.
Figure 2: Serum Calcium LevelsProcess control chart demonstrating the changes occurring in serum calcium level within the first 24 hours by infant. From the mean, the UCL and LCL are +/- 3 SDs. LCL, lower control limit; UCL, upper control limit.