Morphine Clearance and Glomerular Filtration in Sickle Cell Patients in Crisis in Intensive Care

Summary

Background: Sickle cell disease is a genetic disorder of haemoglobin (which carries oxygen in red blood cells). The shape of sickle cell-patients' red blood cells is abnormal. Thus, red blood cells can be blocked in small vessels, responsible for painful crises due to a lack of downstream circulation. These crisis (acute vaso-occlusive crisis) require strong treatment based on morphine, and often require intensive care.However, treatment is often insufficiently effective. Patient can also experiment acute chest syndrome, a complication of vaso-occlusive crisis, which can be responsible for respiratory failure. In addition, patients with sickle cell disease frequently have kidney damage called sickle cell nephropathy, which in the early stages of the disease is responsible for renal hyperfiltration, meaning that the kidneys filter the blood more than necessary, with faster elimination of drugs. For example, it is known that higher doses of antibiotics must be used in these patients than in the general population for the same effectiveness. The hypothesis of the study is that morphine, a drug eliminated by kidneys, is underdosed in patients with sickle cell disease, which is responsible for the difficulties in achieving sufficient analgesia.

Objective: To determine the glomerular filtration rate threshold for which it is necessary to prescribe higher doses of morphine in sickle cell patients with vaso-occlusive crisis.

Methods: inclusion of 100 patients admitted to intensive care for an acute vaso-occlusive crisis or acute chest syndrome and receiving morphine. Within 24 hours of study inclusion, four morphine dosages will be performed, in parallel with a precise determination of the glomerular filtration rate by measuring the elimination rate of a tracer, 100% eliminated by the kidneys and injected at the start of the study. This tracer is iohexol, a contrast agent commonly used in radiology. Morphine underdosage will be interpretated regarding glomerular filtration rate. The effectiveness of analgesia and the amount of analgesics required will be also be analyzed.

Outlook: At the end of this study, the investigators will be able to offer adapted doses of morphine for sickle cell patients in crisis, adapted to glomerular filtration rate, in the aim of personalizing analgesia.

Conditions

• Sickle Cell Disease
• Glomerular Hyperfiltration
• Sickle Cell Nephropathy
• Vaso-Occlusive Crises
• Acute Chest Syndrome

Interventions

DRUG

Injection of iohexol for glomerular filtration rate (GFR) measurement

All patients will receive the same intervention. In included patients, 5 mL of iohexol will be injected, followed by blood sampling 5min, 1hr and 9hrs after iohexol injection for GFR measurement (as iohexol is known to be an exogenous maker for GFR measurement). Analgesia will be protocolized, based in particular on self-administered morphine (patient-controlled-analgesia). Morphine clearance will be measured thanks to 4 blood samples. Blood sampling for morphine and iohexol dosages will be synchronized in order to reduce the number of vascular punctures. Moreover, the first blood sample (5 minutes after iohexol injection) and the 4th blood sample for morphine dosage will be performed at the time of the daily biological analysis, still in order to reduce the number of vascular punctures. Thus, iohexol will be injected 5 minutes before the daily blood sampling for routine biological analysis.

Sponsors & Collaborators

• University Hospital, Tours

  lead OTHER

Study Design

Allocation

NA

Purpose

OTHER

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-03-05

Primary Completion

2028-09-30

Completion

2028-09-30

Countries

• France

Study Locations