With insulin pump therapy, it is easier to adjust the insulin reduction for situations where blood sugar might otherwise drop too low. For instance, during stomach illness or physical activity, the dose of basal insulin can be temporarily reduced for an appropriate period.
If the insulin pump does not have low blood sugar prediction or automatic shutoff, blood sugar can drop too low, just as with MDI. The most common reason is likely the increased insulin sensitivity associated with endurance exercise, which has not been sufficiently anticipated with insulin dose adjustments.
Low blood sugar is treated in the same way as with multiple daily injections, by taking 20 grams of fast-acting carbohydrate and continuing with the pump treatment as normal or with temporarily reduced basal. It is not advisable to detach the pump or cannula because the interruption in insulin delivery will only be noticeable after about an hour.
If the pump or cannula is detached while simultaneously consuming fast-acting carbohydrates, the blood sugar can quickly begin to rise high.