Effect of environmental conditions on performance of elastomeric pumps

Therapeutic Drug Monitoring in Oncology: International Association of Therapeutic Drug Monitoring and Clinical Toxicology Recommendations for 5‐Fluorouracil Therapy

“…If blood sampling for TDM is planned at the end of the drug infusions, patients should be recalled to the center ∼4 hours before the calculated end of infusion to avoid a substantial proportion of TDM failures as a consequence of empty drug pumps. Electric pumps are preferable compared to elastomeric pumps for patients in which 5‐FU TDM is performed, as they have a higher precision with regard to infusion times, while elastomeric pump balloons are sensitive to pressure, temperature, season, and patient activity …”

“…In reviewing 5‐FU PK data, one needs to consider a number of technical and pharmacological issues as to how the various studies were performed. Variability in infusion pump speed will translate in variability in steady‐state plasma concentrations of 5‐FU, especially with the use of elastomeric pump balloons, which are sensitive to pressure, temperature, season, and patient activity, but also with portable pumps delivering in essence a series of boluses . 5‐FU may also be unstable after collection, as it will continue to be metabolized by even small amounts of dihydropyrimidine dehydrogenase (DPD) present in blood and especially the buffy coat .…”

“…Electric pumps are preferable compared to elastomeric pumps for patients in which 5-FU TDM is performed, as they have a higher precision with regard to infusion times, while elastomeric pump balloons are sensitive to pressure, temperature, season, and patient activity. 11,12 While the time of day of the sampling may have an impact on measured concentration through the known circadian variation of 5-FU metabolism, this impact is variable and appears to be relatively small with a difference between 3 PM to 6 AM mean of 1 20% (95% CI 5 12-28%), comparable to even the residual variation within infusion (CV 5 21%). 36 Any such variability should be accommodated by the AUC target range of 20-30 mgÁh/L, and the sample timing could be standardized for a given patient whenever possible.…”

How can we best monitor 5-FU administration to maximize benefit to risk ratio?

“…Morawska et al used this collection strategy, drawing blood samples each morning between 08.00 and 10.00 a.m., the infusion having begun the day before [29].5-FU can be administered by portable diffusers. In this case, it should be noted that the portable diffusers used have a +/-15% flow variation tolerance with respect to the nominal flow rate and it has been shown that its performances may fluctuate depending on atmospheric conditions, pressure and temperature[59] [60]. Although this flow rate variation has no impact on the entire dose received by the patient, it leads to additional inaccuracy in…”

Evaluation of the performance of elastomeric pumps in practice: are we under-delivering on chemotherapy treatments?

“…Ambulatory chemotherapy services have had a significant positive impact on patients' quality of life (QoL), staff workload and NHS costs (Dougherty et al 1998). Despite these advantages, the accuracy of infusion time of these pumps can fluctuate significantly and is dependent on several factors such as temperature and viscosity (Salman et al 2013).…”