If a pt with CHF, kidney failure & sepsis who is nil by mouth has a random glucose that is 5.8 mmol/L & the next day is 3.1 mmol/L, does this matter?

Sepsis- it matters. Criteria for blood glucose levels to "matter", isn't based on just numbers. However, the pt is described having CHF, kidney failure, & sepsis- the pt is unlikely to be clinically improving since 3.1 (about 56 mg/dl) is below the range of normal. Infections will typically cause dysglycemia (hard to control blood sugar levels). When levels return to normal range, it signals clinical improveme.