The incidence of phlebitis development of high concentration of continuous amiodarone infusion with in-line filter compared to the low concentration without in-line filter: a retrospective propensity score-matched analysis.

Background: Phlebitis-associated peripheral infusion of intravenous amiodarone is common in clinical practice, with an incidence between 5% and 65%. Several factors, including drug concentration, catheter size, and in-line filter used, are significantly associated with phlebitis occurrence. Recently an in-line filter was recommended for the reduction of phlebitis, especially in high drug concentration regimens. We performed a retrospective propensity score-matched analysis to find out whether in-line filter will reduce the incidence of amiodarone-induced phlebitis (AIP) in high concentration of amiodarone infusion compared to low concentration without in-line filter.

Methods: Clinical records of all patients who required intravenous amiodarone infusion for cardiac arrhythmias, between January 2017 to December 2019 were retrieved. The incidence of AIP was recorded and subsequently compared among high concentration (2 mg/ml) with an in-line filter and low concentration (1.5 mg/ml) infusion without an in-line filter after a 1 to 2 propensity score matched.

Results: The data indicated that among the 214 cases of amiodarone infusion collected, 28 cases used an in-line filter with high concentration while 186 cases received a low concentration of amiodarone infusion without an in-line filter. After 1:2 propensity score matching, the incidence of phlebitis in the high concentration with in-line filter group was significantly higher than the low concentration without in-line filter group (28.6% vs. 3.6%; P<0.01).

Conclusion: Despite the usage of in-line filter, the high concentration of amiodarone infusion resulted in a higher incidence of peripheral phlebitis. Hence, in the peripheral venous infusion of amiodarone, a high concentration of amiodarone infusion should be omitted from clinical practice. Central venous catheterization for a high concentration of amiodarone infusion is recommended.