Tight glycemic control in the context of intensive care medicine refers to the practice of controlling blood glucose levels to avoid hyperglycemia, which is often observed in patients with critical illness and is associated with higher mortality rates. This is typically done by monitoring a patient's blood glucose levels and administering insulin when they rise much above normal levels. The practice is now considered to be harmful (leading to hypoglycemia), but is still used by a quarter of emergency rooms The glycemic index  is a number from 0 to 100 assigned to a food, with pure glucose arbitrarily given the value of 100, which represents the relative rise in the blood glucose level two hours after consuming that food. The GI of a specific food depends primarily on the quantity and type of carbohydrate it contains; but also is affected by the amount of entrapment of the carbohydrate molecules within the food, the fat and protein content of the food, the amount of organic acids (or their salts) in the food, and whether it is cooked and, if so, how it is cooked. GI tables are available that list many types of foods with their Gis. A food is considered to have a low GI if it is 55 or less; high GI if 70 or more; and mid-range GI if 56 to 69.