None listed
Conditions
Brief summary
Nitric oxide is a chemical released from blood vessel walls and causes vasodilation and low blood pressure known as vasodilatory shock. Vasodilation by this mechanism often occurs in patients who undergo surgeries which need heart lung bypass such as cardiac surgery and can be resistant to normal blood pressure supporting medications. This condition is called vasoplegia. In such patients, methylene blue, which is a common drug that opposes nitric oxide-induced effects on blood vessels may potentially provide a mechanism to reduce the need for blood pressure support in patients having cardiac surgery. Only one previous randomised controlled trial has evaluated the use of methylene blue in patients with post cardiac surgery vasoplegia. A total of 638 patients were screened with 56 who developed post cardiopulmonary vasoplegia included in the trial. Of these, 28 received an infusion of 1.5 mg/kg of methylene blue over 1 hour and 28 received placebo. Mortality was 0% for the methylene blue group and 21.4% in the placebo group. There was also a significant difference in the duration of blood pressure support with all patients in the methylene blue group being successfully weaned from support within 4 hours of the treatment. These results are suggestive of a significant benefit to the routine use of Methylene blue in this group. The objective of the MAGIC trial is to test the hypothesis is that in adults who are invasively mechanically ventilated in the ICU following cardiac surgery with clinically significant vasoplegia who are receiving high doses of blood pressure medications, does a methylene blue infusion at a rate of 1.5mg/kg/hour for one hour increase hours alive and free from blood pressure support at day 10 post randomisation when compared with placebo.
Interventions
Intravenous methylene blue infusion at a rate of 1.5mg/kg/hour for one
hour.
Patients will be assessed by research staff for inclusion in the study within 24 hours of admission to ICU immediately following cardiac surgery. The intervention will be provided to the bedside staff and administered within 1 hour of randomisation.
Sponsors
Medical Research Institute of New Zealand
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
1) Greater than or equal to 18 years of age 2) Invasively mechanically ventilated in ICU within 24 hours of ICU admission and receiving greater than or equal to 10mcg/min of noradrenaline to support mean arterial pressure following cardiac surgery with cardiopulmonary bypass. 3) The clinician considers that vasoplegia is a significant contributor to the haemodynamic disturbance AND this impression is supported by either: 3.1 a cardiac index greater than or equal to 2.5L/min/m2 OR, 3.2 a central venous oxygen saturation greater than or equal to 60%
Exclusion criteria
1. Death is deemed to be inevitable as a result of the current acute illness and either the treating clinician, the patient, or the substitute decision maker are not committed to full active treatment. 2. The patient has mechanical cause of shock such as cardiac tamponade or tension pneumothorax. 3. Mechanical support (e.g. IABP, IMPELLA, or ECMO) or post heart transplant. 4. Enrolment not considered in the patient’s best interest. 5. Patient has an established indication for Methylene Blue 6. Allergy to methylene blue 7. Glucose-6-phosphate dehydrogenase deficiency (risk of haemolytic anaemia). 8. Usually prescribed an SSRI. 9. Pregnant or breast feeding 10. Has already received methylene blue during this hospital admission 11. Previously enrolled in the MAGIC study
Outcome results
None listed