A study of renal blood flow and renal oxygenation measured by magnetic resonance after a standardized fluid challenge in critically ill, resuscitated, patients with sepsis due to COVID-19 or other agents.

Critically ill, septic patients with or without acute kidney injury (AKI) above 18 years of age who have been circulatory and respiratory stabilized will be screened for inclusion.

After the patients have been adequately treated with antimicrobial agents, source control and circulatory and respiratory stabilized, the patient will be moved to the Magnetic resonance imaging (MRI)-suite and placed in the MRI-camera. We plan to, at the same time, study renal blood flow (RBF) and oxygenation with 4 different MRI techniques; arterial spin labeling (ASL), Blood oxygen level dependent (BOLD)-technique, T(2) -Relaxation-Under-Spin-Tagging (TRUST) and Phase contrast at two conditions;

1. at baseline after stabilization
2. after intravenous infusion of 7,5 ml/kg mL Ringer's acetate

The following data will be registered:

1. Age, gender, length and weight,
2. concomitant diseases and treatment,
3. present disease and treatment,
4. source of admission - emergency department or ordinary ward,
5. daily laboratory reports,
6. results from other investigations, e.g. x-rays, cultures etc.,
7. recordings from the intensive care unit (ICU) monitors
8. Continuous renal replacement therapy (CRRT) - duration type, flow rate, replacement fluid, etc.
9. dead or alive at discharge and 90 days mortality,
10. renal function at discharge,
11. treatment restrictions,
12. if the patient has died, the results from a possible postmortem examination. As well as all data obtained during the MRI-examination.

Inclusion Criteria:

• Patients with clinical diagnosis sepsis (infection and organ dysfuncion) treated in intensive care.
• Manifest Acute kidney injury (AKI) or risk of AKI.
• 18 years of age or older

Exclusion Criteria:

• Pregnancy
• Chronic kidney failure
• Renal Replacement Therapy
• Instability in vital parameters to a degree where MRI is not feasible
• Contraindications for MRI (implants, coils, pacemakers, etc)