Dexmedetomidine pharmacodynamics and population pharmacokinetics in elderly intensive care unit (ICU) patients

This study looks at the best dose of dexmedetomidine (a sedation medication) for elderly ICU patients aged 65 and above who are on a breathing machine. Current dosing guidelines suggest lower doses for older patients, but the exact right dose is not yet known. The study will collect blood samples during sedation to analyze how the drug behaves in the body and recommend the safest and most effective dose for older ICU patients. You may be eligible if: - You are 65 years or older - You are in the ICU and require breathing machine support for at least 48 hours - You need sedation as part of your ICU care You may NOT be eligible if: - You or your family refuses participation - You have had a previous bad reaction to alpha-2 agonist medications - You have a second-degree or higher heart block - You have liver failure - You have kidney failure requiring dialysis Talk to your doctor about whether this trial might be right for you.