Diabetes in ICU

For managing Diabetes in ICU, maintaining euglycemia (defined as glucose <110 mg/dL in intensive care unit settings and <180 mg/dL in non intensive care unit settings by American College of Endocrinology Consensus Guidelines) has been shown to greatly reduce morbidity and mortality.

This has created a paradigm shift in the inpatient setting where the goal is now to prevent hyperglycemia rather than treat hyperglycemia after it develops in diabetes in ICU .

Insulin, in both intravenous and subcutaneous regimens, is being used in the inpatient setting to achieve optimum glucose control.

The clinical challenge with the use of insulin includes recognizing when to hold or decrease insulin and in which type of diabetic patient insulin should be adjusted in the nil per os (NPO) setting.

Considerable confusion has been caused by the previous diabetes classifications of insulin-dependent diabetes mellitus (IDDM) and non  insulin-dependent diabetes mellitus (NIDDM), especially in diabetes in ICU .

Because of the obesity epidemic, NIDDM patients often progress to requiring insulin, causing health care providers to then refer to these patients as having IDDM.

Yet, the NIDDM patient who progressed to requiring insulin is physiologically very different from the patient who was diagnosed initially as an IDDM patient. While both patients require insulin, the physiological cause of their insulin requirement and the response to exogenous insulin is significantly different.

In response to this issue, diabetes is now classified based on the etiology of the respective disease process. These classifications are as follows:

  • Type I Diabetes: Characterized by absolute insulin deficiency. The patient is physiologically unable to make endogenous insulin. This inability is due to either an immune-mediated process or severe injury or resection of the pancreas. In rare cases, there is an idiopathic process leading to beta cell destruction.
  • Type II Diabetes: Varying degree of insulin resistance and relative insulin deficiency. This can occur in both children and adults and is most often associated with obesity. It is often treated initially with oral agents but will usually progress to requiring insulin for adequate glucose control.


Features of insulin deficiency and diabetes in ICU include the following:

  • Type I diabetic patients
  • Type II diabetic patients who have required insulin therapy for >5 years
  • Type II diabetic patients or who have been diagnosed as a type II diabetic for >10 years
  • Patients who have undergone a total pancreatectomy

It is recommended that patients of diabetes in ICU who are insulin deficient must be given some form of basal insulin either as an insulin infusion or as a subcutaneous intermediate (NPH) or long-acting (glargine) insulin to prevent diabetic ketoacidosis, even in the patient who is NPO.

It is often difficult to ascertain which patients are insulin deficient. If it is unclear which type of diabetes in ICU a patient may have, the following physiological indictors of insulin deficiency should be considered:

  • Positive serum or urine ketones
  • Wide fluctuations in glucose values
  • History of requiring insulin therapy to control blood sugar since initial diagnosis
  • Previous admissions for diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemia nonketotic syndrome (HHNK)



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