Impact of the anticipated preparation of portable diffusers on their diffusion rates

Context and objectives

To optimize the chemotherapies’ production flow for day hospitals, it would be interesting for our cytotoxic preparation unit to anticipate the preparation of the 5-Fluorouracil (5FU) diffusers.
Since the flow rate of diffusers is known to be unstable over time, it is necessary to check whether the anticipation of the preparation affects the flow rate of the diffusers.
This work aims to measure the impact of preliminary preparation of the diffusers on their flow rates.

Materials and methods

The study is carried out on 3 groups of 9 diffusers with a nominal flow-rate of 2ml/h (SV2 Baxter®)

• a control group with an unclamping of the diffuser the day of its preparation. (H0)
• a group where the diffuser is unclamped 24h after its preparation (H24)
• a group where the diffuser is unclamped 72h after its preparation (H72)

Each diffuser is filled with NaCl 0.9% as recommended, weighted once full (Pp) and stored at room temperature until unclamping.
After unclamping, the tubes are placed at 35°C for a diffusion time of 48h. The diffusers are then weighted (Pv) at the end of the diffusion.
Flow rate (ml/h) = [(Pp-Pv)/1.004]/ diffusion time.
Flow rates between groups were compared with a Wilcoxon test. The number of diffusers was determined to demonstrate a difference in the flow rates of 10% with a statistical power of 90% and a value-at-risk of á=5%

Results and conclusion

The medium flow rates are, respectively of 2.00 ml/h (H0), 1.94ml/h (H24) and 2.00ml/h (H72).
Their comparison did not showed a significant difference: pH24 = 0.2154 and pH72 = 0.9645.
We can therefore anticipate the preparation of diffusers up to 72h without fearing flow rate variations.