(475) Flat-Dose Versus Weight-Based-Dosed Gentamicin for the Initial Treatment of Intraamniotic Infections

Introduction: Intraamniotic infections (IAI) are characterized by inflammation of amniotic fluid, placenta, fetus, fetal membranes, or decidua. Timely administration of intrapartum antibiotics when IAI is suspected has been associated with a 10-fold decrease in neonatal sepsis in previous literature. University Hospitals Cleveland Medical Center adjusted their IAI guidelines by incorporating an initial flat dose of gentamicin (400 mg), replacing the individualized weight-based dose (5 mg/kg), to facilitate a more rapid administration of antibiotics. Flat dose gentamicin for IAI has not been previously evaluated. The purpose of this study was to compare the time to administration of flat dose gentamicin to weight-based and assess clinical outcomes.

Methods: This was a single-center retrospective chart review including 126 women between June, 2021-December, 2021 (pre-implementation group) and June, 2022-December, 2022 (post-implementation group). The primary endpoint was to compare the time to administration between groups. Secondary endpoints included time to verification, time to administration from verification, reasons for delays, and maternal/ neonatal complications. Data was analyzed using descriptive statistics, Chi square/ Fisher's exact tests, and Student's T test's. All statistical tests were two-sided with p< 0.05 defined as statistically significant.

Results: There were 63 patients evaluated in each treatment arm with the only significant differences in baseline characteristics between the weight-based dose and the flat dose gentamicin groups being the mothers’ ages (27 years (standard deviation (SD) 5.88) vs 25 years (SD 5.76). Flat dose gentamicin was associated with a decreased time to administration from time ordered (79.0 minutes (SD 117.34) vs 162.2 minutes (SD 118.67); p-value < 0.001), time to verification (8.0 minutes (SD 9.72) vs 16.5 minutes (SD 17.45); p-value = 0.001), and time to administration from verification (71.0 minutes (SD 116.83) vs 145.7 (SD 117.53) p-value < 0.001). While this study was not powered for maternal/ neonatal complications, there were no significant differences between groups except for a reduction in post-partum hemorrhages (1.6% vs 14.3%; p-value = 0.008).

Conclusions: Flat dose gentamicin improved time to administration of antibiotics for IAI.