Intranasal insulin for treatment of delirium.

Delirium is a common medical condition characterised by sudden and fluctuating disturbances in thinking, attention and consciousness. Affecting up to one in four hospitalised older people, delirium is considered a medical emergency because it causes premature death, admission to nursing home, dementia, longer stays in hospital and loss of independence. Currently, there are no licenced treatments for people with delirium for use in the Emergency Department or on hospital wards. The most popular off-licence treatment for delirium, antipsychotics, was recently shown to worsen symptoms and increase death. The need to discover safe treatments is urgent. Recent research has identified significant changes in brain glucose (sugar) metabolism during an episode of delirium. Insulin receptors are widely expressed in the brain and insulin delivered via nasal spray (intranasal insulin) has been shown to increase glucose uptake in the brain. Intranasal insulin has been tested in older people and was found to be safe and may be associated with an improved cognitive function. The effect of intranasal insulin in delirium has previously not been evaluated. We will study intranasal insulin to treat delirium in people coming to the Emergency Department at Prince of Wales Hospital. We will conduct a randomised double blind placebo controlled trial of 100 patients and scientifically evaluate the effect of intranasal insulin compared to salt water (saline). Neither the Doctor nor the study participant knows which treatment the participant is receiving. Patients will be reviewed daily by an Aged Care Specialist while they have delirium and be followed up at six months. The primary objective is to evaluate if intranasal insulin reduces the duration of delirium in hospitalised older adults. Secondary objectives will assess if intranasal insulin decreases the length of hospital stay, reduces the percentage of people discharged to residential care, reduces death during admission and at six months, reduces delirium severity and preserves cognitive status six months post-delirium.