Commentary by Mary Vouyiouklis MD, Fellow, and Ann Danoff MD, Director, Division of Endocrinology, Diabetes and Metabolism, NYU Medical Center
Welcome to Case 3 of our special diabetes series intended to highlight the essentials of diabetes care in the inpatient setting. For the next several weeks, we plan to present individual cases followed by some management questions and answers.
Case 3: The case of Mr. Mejia
3A. Mr. Mejia is a 30 year old man with Type 1 diabetes who is admitted for shortness of breath. He is made NPO for an imaging study the following morning. His usual insulin regimen is 10 units of rapid acting insulin qAC and 18 units of glargine qHS. You are covering for your co-intern and the nurse calls you asking you if you need to make any adjustments given that he is now NPO. What do you do?
Discontinue the qAC but continue the qHS.
Discontinue the qAC and half the qHS dose.
Discontinue all and start a sliding scale.
3B. Mr. Mejia becomes hypoxic and unfortunately has to be intubated. He now is given continuous tube feeds. What are the adjustments (if any) that need to be made now?
3A. Answer: 2
Patients with type 1 diabetes have an absolute requirement for insulin, therefore basal insulin replacement is an absolute requirement to prevent ketoacidosis, even when they are NPO. In this instance, the patient’s qHS dose is providing < 50% of his/her TDD therefore it is reasonable to continue with this and to hold the pre-meal bolus dosing while the patient remains NPO.
Although patients with T2DM may not be at risk for DKA, if insulin is not administered when they are NPO, these patients should receive ½ to 2/3rds of their basal insulin dose, depending upon degree of previous glycemic control, as assessed by report of fingerstick monitoring and/or recent HgA1C results.
An insulin drip would be ideal for an intubated patient on tube feeds in a properly monitored setting. When he is extubated and stabilized, but still requires tube feeds, a number of options for insulin administration are reasonable. He could be switched to a basal insulin regimen comprised of either NPH q8H or Lantus. Alternatively, this is one of the few situations where “RISS” would also be acceptable. If the tube feeds are administered over a 8 – 12 hour period (rather than continuously), an insulin such as NPH (which has an onset of action in ~ 2 hours and a peak action in ~ 6 – 8 hours) would provide a better match for this carbohydrate load than “peakless” insulinization with glargine; therefore would be preferable in that circumstance.