Intranasal insulin for the prevention of delirium in ICU patients undergoing elective cardiac surgery: a randomized, double blind, placebo controlled pilot trial (INSPIRE)
After major heart surgery, some patients experience sudden confusion, memory problems, or distress. Doctors call this condition delirium, and it is common in intensive care units (ICUs). Delirium can slow down recovery and lead to longer hospital stays. The INSPIRE study is investigating whether giving a small dose of insulin as a nasal spray can help protect the brain and prevent delirium. When sprayed into the nose, insulin can reach the brain directly. Patients having planned heart surgery will receive either the insulin spray or an inactive saltwater (placebo) spray. The study team will check for side effects like runny noses or low blood sugar levels. They will also track how clear-headed patients remain, how long they stay in intensive care, and how well their memory works during a short phone call 30 days after surgery.
At a glance
What is this study about?
Heart surgery is a major operation that places stress on the body. While recovering in the intensive care unit (ICU), many patients develop a temporary state of acute confusion known as delirium. People with delirium may feel frightened, hallucinate, struggle to understand where they are, or become unusually quiet and drowsy. Delirium can make recovery harder and lead to longer stays in hospital.
Researchers are looking for simple, safe ways to protect brain cells during and after surgery. Insulin is a natural hormone that helps cells use energy. Early research suggests that insulin delivered directly through the nose can travel into the brain to support brain cells without causing major changes to blood sugar levels in the rest of the body.
This pilot trial compares the insulin nasal spray with a dummy spray made of simple saltwater (a placebo). By comparing the two groups, researchers hope to see if the spray is easy for nurses to give, whether patients tolerate it well, and if it truly lowers the chances of developing delirium.
The findings from this study will help doctors design larger trials in the future, with the ultimate goal of making heart surgery safer and less stressful for patients and their families.
Key takeaways
- The study tests whether an insulin nasal spray can prevent confusion (delirium) after planned heart surgery.
- Half of the participants receive the insulin spray and half receive a harmless saltwater placebo.
- Your blood sugar and nasal comfort will be carefully monitored while you are in hospital.
- Taking part includes short memory checks before your operation and a follow-up phone call 30 days later.
- Participation is entirely voluntary and does not change your routine surgical care.
Who may be eligible?
This study is designed for adults who are scheduled to have planned (elective) heart surgery and are expected to recover in the intensive care unit afterwards. Both men and women can take part.
To be included, patients need to be able to use a nasal spray and agree to have their memory and thinking checked before surgery and one month afterwards.
Patients who are having emergency heart surgery, or those with certain medical conditions that make nasal sprays or trial medicines unsafe, may not be able to join. The hospital care team will check your full medical history before inviting you to take part.
Could this study suit you?
Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.
- I am scheduled to have planned (elective) heart surgery.
- I will be recovering in the intensive care unit (ICU) after my operation.
- I am able and willing to use a nasal spray.
- I can take part in a short telephone check before surgery and one month after.
What does participation involve?
If you decide to join the study, you will have a brief memory and thinking assessment over the phone about two weeks before your planned surgery. Around the time of your operation, nursing staff will give you the trial nasal spray, which will contain either insulin or harmless saltwater.
While you are recovering in the intensive care unit and on the hospital ward, staff will check your nose for any mild irritation and monitor your blood sugar levels carefully. They will also carry out short, daily bedside checks to see how alert and clear-headed you feel. Around 30 days after your operation, a researcher will call you at home for a final 15-minute phone check to see how your memory and recovery are progressing. Your total time in the study is approximately six to eight weeks.
Potential risks and benefits
Locations (1)
- —UnverifiedNetherlands
Common questions
What is delirium?
Delirium is a sudden state of confusion that often happens when someone is seriously ill or recovering from major surgery. It usually passes once the person recovers.
Why give insulin through the nose?
Spraying insulin into the nose allows it to travel directly to the brain to help brain cells, while reducing the risk of lowering blood sugar in the rest of the body.
Will I definitely receive the insulin spray?
No. This is a randomised trial, meaning a computer randomly chooses whether you receive insulin or a harmless saltwater spray. Neither you nor your doctors can choose.
Does this replace my normal heart surgery care?
No. You will receive all of your standard surgical care, anaesthesia, pain relief, and nursing support as normal.
Can I leave the study if I change my mind?
Yes. You are free to stop taking part at any time. You do not need to give a reason, and your medical care will continue as normal.
How to find out more
Always speak to your GP or specialist before deciding to take part in a study.
Interested in taking part?
Discussion
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