Sliding scale insulin is sometimes used by doctors to help regulate a patient's blood sugar levels. Although it can be helpful for some, its effectiveness is questionable, and a good deal of controversy surrounds its use.
Sliding scale insulin is generally defined as a set of instructions for administering insulin dosages based on specific blood glucose readings. Some sliding scales are in the form of general charts that are used for many different patients with doses given based on the patient's weight and activity level. Other sliding scales are individualised with guidelines and doses calculated for the individual patient by a doctor based on the patient's specific needs and medical history.
Sliding scale insulin is often used short-term during periods of insulin adjustment, illness, hospitalisation or any other time when acute management of insulin becomes necessary. It can also be ordered as a standing order backup to an ongoing glucose management plan (i.e. give 2 additional units if blood sugar level goes above 200) or as the sole means of insulin management where blood glucose checks are done at regular intervals and sliding scale insulin is given each time based on the results. This method is not recommended for the long term.
A sliding scale allows patients and nurses to administer insulin doses based on blood sugar readings without needing to consult with the doctor each and every time. It can also be helpful in the treatment of very brittle or unstable diabetics that can have sudden or unexpected blood sugar level spikes and need immediate dosing. (See Reference #1, #2, #3)
Because insulin dosages are dependent on individual blood glucose readings, the sliding scale is a reactive approach to insulin management versus a proactive one. It can also lead to large swings in blood sugar levels as opposed to more desirable steady numbers. Insulin via sliding scale is considered a less-than-ideal treatment method by many professionals because it does not prevent high blood sugar levels but only responds to them once they've occurred.
The medical community is growing increasingly negative about sliding scale insulin, with many calling it an out-of-date and antiquated way of managing diabetic patients. Some even go so far as to say it's the "lazy" approach and a method that is often used by doctors who simply don't want to be bothered by nurses calling frequently for new insulin orders.