Intranasal Insulin for Neuroprotection in Elderly Cardiac Surgery Patients

Nearly half of all intensive care unit (ICU) admissions consist of adults > 65 years old, an age group that is at high risk for developing cognitive decline and delirium in the ICU. Over 50% and 70% of critically ill cardiac surgery patients develop post-operative delirium (POD) and post-operative cognitive decline (POCD), respectively. These two forms of acute cognitive dysfunction are associated with increased mortality and poor functional recovery. While distinct conditions, POD has been associated with the subsequent development of POCD, suggesting a mechanistic link.

No proven pharmacologic treatments targeting the prevention of both POD and POCD in elderly patients exist to date. Recent data suggest that insulin administered into the central nervous system via intranasal delivery improves cognitive function in elderly patients with Alzheimer's disease and mild cognitive impairment. However, its utility in preventing POD and POCD in elderly critically ill patients has not been investigated.

The hypothesis of this study is that intranasal insulin can prevent POD and POCD in elderly critically ill patients admitted to the intensive care unit after undergoing cardiac surgery. To test this hypothesis, this randomized, placebo-controlled, double-blinded Phase II study will enroll 60 patients >= 65 years old undergoing elective coronary artery bypass graft and/or valve surgery requiring cardiopulmonary bypass, and will treat them with either 40 IU of aspart insulin or placebo intranasally before surgery and then four times a day for 7 days or until hospital discharge (whichever occurs first).