2021 FDA Science Forum
A Method for Simulating Clinical Use of Luer Valve Disinfectant Caps for Estimating a Worst-Case Exposure Dose of Isopropyl Alcohol (IPA) in Neonatal Intensive Care Unit (NICU) Patients
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Contributing OfficeCenter for Devices and Radiological Health
Abstract
Isopropyl alcohol (IPA)-filled caps are single-use devices that attach to luer access valves (LAV). The IPA-filled caps are intended to be used to disinfect and provide a physical barrier to contamination of the LAV. Previous studies have simulated clinical use of IPA caps in neonatal intensive care units (NICUs) neonates and reported altered appearance of luer valves, as well as excess IPA quantity in saline. In the present study, a mock central line circuit and drug infusion protocol were developed to simulate worst-case use of IPA-filled disinfectant caps and estimate a maximum IPA blood concentration that might occur in NICU patients. The mock drug infusion protocol was based on a worst-case clinical use scenario, as determined using survey information from NICUs, and included the following steps: (1) incubating LAV with IPA caps at 37°C, (2) hourly drug infusions, and (3) wiping proximal end of the LAV with a commercially available medical IPA impregnated pad after cap removal, as well as before subsequent attachment of a fresh IPA-filled cap. The control and test groups were the LAV + IPA pad only and LAV + IPA disinfectant cap + IPA pad, respectively. The quantity of IPA in collected infusates was determined by head-space gas chromatography with flame ionization detector. IPA concentrations in infusates were used to estimate the blood concentrations of IPA in NICU neonates using pharmacokinetic modeling and simulations for four hypothetical clinical use scenarios (6, 12, 18, and 24 i.v. pushes hourly) that would result in 6, 12, 18, and 24 caps used in a single day. Simulating twenty four i.v. pushes hourly resulted in measured IPA concentration that were up to 20x higher in IPA disinfectant cap infusates compared to the IPA pad alone. Based on the pharmacokinetic model, hourly i.v. pushes predicted accumulation of IPA in neonatal blood that were higher with disinfectant cap use compared to IPA pad alone.
