Accuracy and Precision of the SynchroMed II Pump

Abstract

The objective of this study was to evaluate the accuracy and precision of SynchroMed II programmable infusion pumps for delivery of intrathecal baclofen to treat severe spasticity. Retrospective chart review study. Urban academic rehabilitation clinic. Patients with spasticity treated with intrathecal baclofen. A retrospective chart review of 149 patients inclusive of 755 individual patient encounters more than a 2.5-year span for baclofen pump refills was performed. Charts were reviewed to obtain data on the concentration and dose of intrathecal baclofen, aspirated and residual volumes, age of the pump, and reservoir volume of the pump. Flow rate (mL/day) was calculated for each chronological visit. Flow rates from clinical data were used to calculate the accuracy and precision based on the manufacturer's specifications for both the 20 mL and 40 mL pumps. The infused volume accuracy and precision of both the 20 mL pumps and 40 mL pumps remained within manufacturer's specifications while delivering drug at a rate slightly lower than predicted. There were no cases of pump over-infusion. There is a statistically significant decrease in flow rate accuracy over the lifespan of the pump. SynchroMed II pumps infuse at slightly less than their predicted rate while remaining within the manufacturer's specifications. No pump over-infusions were noted. Pump flow rate declines over time. Further study is warranted to assess the impact of this flow rate decrease on patient treatment and safety.