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Comparative Study
. 2010 Jan 1;4(1):98-103.
doi: 10.1177/193229681000400112.

Siphon effects on continuous subcutaneous insulin infusion pump delivery performance

Howard C Zisser  1 , Wendy Bevier, Eyal Dassau, Lois Jovanovic
Affiliations
Comparative Study

Siphon effects on continuous subcutaneous insulin infusion pump delivery performance

Howard C Zisser et al. J Diabetes Sci Technol. .

Abstract

Background: The objective was to quantify hydrostatic effects on continuous subcutaneous insulin infusion (CSII) pumps during basal and bolus insulin delivery.

Methods: We tested CSII pumps from Medtronic Diabetes (MiniMed 512 and 515), Smiths Medical (Deltec Cozmo 1700), and Insulet (OmniPod) using insulin aspart (Novolog, Novo Nordisk). Pumps were filled and primed per manufacturer's instructions. The fluid level change was measured using an inline graduated glass pipette (100 microl) when the pipette was moved in relation to the pump (80 cm Cosmo and 110 cm Medtronics) and when level. Pumps were compared during 1 and 5 U boluses and basal insulin delivery of 1.0 and 1.5 U/h.

Results: Pronounced differences were seen during basal delivery in pumps using 80-100 cm tubing. For the 1 U/h rate, differences ranged from 74.5% of the expected delivery when the pumps were below the pipettes and pumping upward to 123.3% when the pumps were above the pipettes and pumping downward. For the 1.5 U/h rate, differences ranged from 86.7% to 117.0% when the pumps were below or above the pipettes, respectively. Compared to pumps with tubing, OmniPod performed with significantly less variation in insulin delivery.

Conclusions: Changing position of a conventional CSII pump in relation to its tubing results in significant changes in insulin delivery. The siphon effect in the tubing may affect the accuracy of insulin delivery, especially during low basal rates. This effect has been reported when syringe pumps were moved in relation to infusion sites but has not been reported with CSII pumps.

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Figures

Figure 1.
Figure 1.
Pump testing setup. A, 100 μl pipette in stand; B, pump with tubing, level; C, OmniPod in stand; D, pipette close-up.
Figure 2.
Figure 2.
Percentage of expected delivery for 1.0 U/h basal rate. Cosmo, magenta columns; MiniMed 512, blue columns; MiniMed 515, yellow columns; OmniPod, light blue columns. The asterisk represents significant difference from level (p < .05).
Figure 3.
Figure 3.
Percentage of expected delivery for 1.5 U/h basal rate. Cosmo, magenta columns; MiniMed 512, blue columns; MiniMed 515, yellow columns; OmniPod, light blue columns. The asterisk represents significant difference from level (p < .05).
Figure 4.
Figure 4.
In silico basal rate simulation. This simulation describes 3 h with the optimal basal and 8 h with +/−25% of the optimal basal. The target glucose is 150 mg/dl.
See this image and copyright information in PMC

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References

    1. Pickup J, Keen H. Continuous subcutaneous insulin infusion at 25 years: evidence base for the expanding use of insulin pump therapy in type 1 diabetes. Diabetes Care. 2002;25(3):593–598. - PubMed
    1. Hoogma RP, Hammond PJ, Gomis R, Kerr D, Bruttomesso D, Bouter KP, Wiefels KJ, de la Calle H, Schweitzer DH, Pfohl M, Torlone E, Krinelke LG, Bolli GB 5-Nations Study Group. Comparison of the effects of continuous subcutaneous insulin infusion (CSII) and NPH-based multiple daily insulin injections (MDI) on glycaemic control and quality of life: results of the 5-nations trial. Diabet Med. 2006;23(2):141–147. - PubMed
    1. Bruttomesso D, Costa S, Baritussio A. Continuous subcutaneous insulin infusion (CSII) 30 years later: still the best option for insulin therapy. Diabetes Metab Res Rev. 2009;25(2):99–111. - PubMed
    1. The Diabetes Control Complications Trial Research Group. The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus. N Engl J Med. 1993;329(14):977–986. - PubMed
    1. Skyler JS, Ponder S, Kruger DF, Matheson D, Parkin CG. Is there a place for insulin pump therapy in your practice? Clin Diabetes. 2007;25(2):50–56.

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