I’m sorry the health-care system threatens your access to continuing insulin pump therapy. I use a pump with a 300-unit cartridge and my usage rate allows me to use one cartridge and the attached tubing for about nine days.
I would caution you, however, to reconsider your site change frequency. I’ve been pumping almost continuously since 1987. Mostly due to convenience I started to leave my infusion sites in place longer than three days as long as my blood glucose levels were reasonable.
Within a few years of starting that practice I began to have troubles with poor site absorption. It took me several months to restore dependable insulin absorption. I changed infusion set styles and starting using new locations on my body. I gave my stomach a few years rest and now I’m using it again to good effect.
My practice now is to faithfully changes my infusion sites at three days. I will also change any site that remains painful 12 hours after a site change. I wait the 12 hours since the site pain often goes away and the site performs well.
Be aware that over-using an infusion site can lead to abnormal and unsightly fat growth (lipohypertrophy) and scar tissue. Sometimes that means that you’ll never be able to use that site again for insulin infusion. I’m sympathetic to your motivation to economize and protect yourself from the vagaries of health-care bureaucrats but don’t risk ruining your infusion sites.
I hope your November appointment goes well and the NHS auditors do not take away your pump therapy. Please let us know what happens.