Microcirculatory Effects of Methylene Blue (MAGIC BLUE)
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|ClinicalTrials.gov Identifier: NCT04250389|
Recruitment Status : Completed
First Posted : January 31, 2020
Last Update Posted : January 31, 2020
International guidelines recommend Methylene Blue (MB) as a second-line drug in the treatment of norepinephrine refractory vasoplegic shock (VS) after Cardiopulmonary Bypass CPB. Macrocirculatory effects of MB in this setting are now well established but microcirculatory effects of MB remain unknown.
The purpose of this study is to assess the micro vascular effects of a single administration of methylene blue (1.5 mg/kg over 30 minutes) for norepinephrine-refractory VS post CPB.
Microcirculatory effect will be monitored before and one hour after MB infusion through cutaneous refill time, video microscopy measurements of the sublingual microcirculation and tissue oxygen saturation combined with vascular occlusion test (VOT).
|Condition or disease||Intervention/treatment|
|Acute Circulatory Failure||Other: Hemodynamic assessment (micro and macrocirculatory)|
|Study Type :||Observational|
|Actual Enrollment :||25 participants|
|Official Title:||Microcirculatory Effects of Methylene Blue in Vasoplegic Shock After Cardiopulmonary Bypass: a Pilot Study|
|Actual Study Start Date :||January 1, 2017|
|Actual Primary Completion Date :||January 1, 2017|
|Actual Study Completion Date :||June 2019|
Patients with VS receiving methylene blue infusion
The studied population will be all patients receiving methylene blue for refractory vasoplegic shock (VS) after Cardiopulmonary Bypass (CPB). Refractory VS is defined as follow: a dose of norepinephrine > 0.5µg/kg/min to obtain a mean arterial pressure of 65-75 mmHg with a normal or increase cardiac (> 2 L.min-1.m-2). Patients will be included in the investigator's 20-bed adult cardiothoracic intensive care unit (ICU) in a tertiary teaching hospital (Hopital Cardiologique Louis Pradel, Hospices Civils de Lyon).
Other: Hemodynamic assessment (micro and macrocirculatory)
Each of the variable related to macro- and microcirculatory will be evaluated before and one hour after start of MB infusion.
Macrocirculatory parameters will include :
Microcirculatory parameters will include :
- Change in tissue oxygenation (resaturation speed expressed as %/sec) during the vessel obstruction test. [ Time Frame: one hour after the start of methylene blue infusion ]The resaturation speed during reperfusion is defined as maximum StO2 - minimum StO2 /time of reperfusion. Tissue oxygen saturation (StO2) will be measured by near-infrared reflectance spectroscopy (NIRS) optode applied to the medial surface of the left or right forearm, 5 cm below the elbow. The sensor will be connected to the four-wavelength O3 Regional Oximetry device (Masimo Incorporation). All StO2 values will be recorded continuously and read every second. Data will be recorded online, transferred to a laptop with a specific software designed by Masimo (Masimo Instrument Configuration Tool (MICT) Version 22.214.171.124), and stored for further analysis. After completion of a baseline set of measurements for each patient, a vascular occlusion test (VOT) will be then perform using a manual pneumatic cuff inflator (Spengler SAS, Antony, France) positioned at the upper extremity of the ipsilateral upper limb.
- Video microscopy measurements of the sublingual microcirculation [ Time Frame: one hour after the start of methylene blue infusion ]Proportion of Perfused Vessel (PPV), Total Vessel Density (TVD), Perfused Vessel Density (PVD), Microcirculatory Flow Index (MFI) and heterogeneity index will be reported. Video microscopy measurements will be collected before and one hour after the beginning of MB infusion.
- Cutaneous and gingival refill time [ Time Frame: one hour after the start of methylene blue infusion ]Five consecutive cutaneous recoloration time (CRT) acquisitions on the thorax and five consecutive gingival recoloration time (GRT) acquisitions will be made after calibrated compression of the skin and the gingiva. These measurements will be collected before and one hour after the beginning of MB infusion.
- Metabolic variables [ Time Frame: one hour after the start of methylene blue infusion ]Arterial blood gases including arterial lactate and central venous blood gases will be withdrawn before and one hour after the beginning of MB infusion concomitantly to measurement of cardiac output to allow calculation of oxygen delivery (DO2), oxygen uptake (VO2), oxygen extraction ratio (ER), venous-to-arterial difference in carbon dioxide partial pressure (PCO2gap), modified respiratory quotient (RQ modified) and ratio of central venous-to-arterial carbon dioxide content to arteriovenous oxygen content (DavCO2/DavO2).
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04250389
|Service d'anesthesie reanimation, Hôpital cardiologique Louis Pradel|
|Bron, France, 69500|