Inclusion Criteria:  Patient or legal representative accepted trial enrollment Age above 18 years Chronic or acute kidney injury in need for renal replacement therapy Blood pressure lower than 100 mmHg or in use of any vasopressor  Exclusion Criteria:  Pregnancy Death considered imminent in the next 24 hours Patients not on full code status Hypertensive patients where dialysis was indicated to remove fluids Known allergy to methylene blue Known glucose-6-phosphate deficiency Previously enrolled in the trial Acute coronary Syndrome Domiciliary nitrate use