Hi Akasha,
to add to Tom's response and to try to answer your questions:
As Tom says, the pump (about the size of the old style pagers) delivers a constant supply of short acting insulin, this is the basal dosage and replaces your levemir or lantus injections and can be programmed to deliver at different rates during the day according to your body's needs. This can also be adjusted temporarily to take account of exercise etc.
When you eat any food containing carbs, you press a few buttons on the pump so that it delivers a bolus dose based on your insulin to carbs ratio, this replaces the short acting insulin (humalog, actrapid etc.) that you would normally inject before each meal.
The pump has a reservoir (or cartridge) that you fill with short acting insulin. Depending on the pump this hold anything from 180 units to 300 units of insulin and will last three to six days depending on your insulin requirements. When it gets empty, you will need to replace the cartridge.
The pump delivers the insulin through a cannula to which it is connected by a very thin felxible tube. The cannula is a small metal or teflon needle (usually about 8 or 9mm long) inserted into the skin in either the abdomen, buttocks, thighs etc. (basically it can be inserted in any site that you currently inject into. The cannula needs to be replaced and re-sited every two or three days. You need to rotate the sites as you currently roatate you current injection sites.
You still need to test you BG levels (possibly more than you do now) so that you can do any corrections to bolus doses etc. and to check that BGs are withn the correct range and to make sure that there are no problems with the pump delivery (sometimes cannulas get blocked or air bubbles appear in the lines).
You need to be connected to the pump 24 hours a day but can disconnect for up to an hour for a shower, swimming, etc (or as my DSN put it, if you want to 'get intimate' 🙂). I thought being connected 24 hours would be a big issue for me but it's not been a problem at all. it's amazing how quickly you get used to it.
You need to carry an emergency kit with you at all times in case of any issues. This will contain a spare filled reservoir, a spare cannula and tube, a spare battery, ketostix and finally a syringe and insulin vial in case of total pump failure. Sounds a lot but it's suprising hpw small it can be packed down.
The theory with a pump is that the basal rate takes care of your backkground needs and that you shouldn't need to snack. You can then eat when you want to not because you have to to. You just need to deliver a bolus dose each time you eat any carbs. That's the theory anyway. You will still have the odd hypo that needs correcting but these should be less often and less severe that those that you experience with MDI.
Phew, I think that's about it. If the above raises any questions, then just shout.
