Sickle cell disease is a genetic condition affecting the red blood cells, which are usually round but turn sickle-shaped in these patients, blocking small blood vessels and causing pain. Morphine, a pain-relieving medicine processed by the kidneys, is often given during these painful crises. The study checks if sickle cell patients in crisis need more morphine than usually given because their kidneys might filter it out too quickly. The study involves 100 patients in intensive care receiving morphine. Researchers will measure how fast the kidneys filter using a safe tracer called iohexol. The goal is to find out the right dose of morphine for better pain relief.

• Participants will have four morphine dosages measured within 24 hours of joining the study.
• This study is for adults with sickle cell disease admitted to intensive care.
• Exclusion includes prior study participation or certain medical conditions.