Skip to main content
OpenTrials
Completed

NCT Number: NCT04250389

Microcirculatory Effects of Methylene Blue

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).

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Acute Circulatory Failure Pathologic Processes Pathological Conditions, Signs and Symptoms Shock

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Service d'anesthesie reanimation, Hôpital cardiologique Louis Pradel

Bron, 69500, France

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • patients receiving methylene blue prescribed by the clinician in charge of the patient
  • patient receiving a dose of norepinephrine > 0.5µg/kg/min
  • normal or increase cardiac (> 2 L.min-1.m-2) at the time of inclusion
  • vasoplegic syndrome post cardiopulmonary bypass for cardiac surgery

Exclusion criteria

  • the need for hemodynamic intervention during the time of study (fluid resuscitation, introduction of inotropic or vasopressor support, change in inotropic support dose)
  • age under 18 years

Treatment and study plan

Hemodynamic assessment (micro and macrocirculatory)

Other

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 :

  • Mean, systolic, diastolic arterial, heart rate (HR)
  • Cardiac output (CO), sequential vascular response (SVR) and stroke volume (obtained with transthoracic echocardiography or transpulmonary thermodilution catheter if available).
  • A passive leg raising (PLR) test will be performed before and one hour after MB infusion. Patients will be classified as fluid responder if they had a CO of at least 10% after PLR.

Microcirculatory parameters will include :

  • Cutaneous and gingival refill time
  • Tissue oxygen saturation combined with vascular occlusion test (VOT)
  • Video microscopy measurements of the sublingual microcirculation
  • Metabolic variables: Arterial blood gases including arterial lactate and central venous blood gases.

Primary outcomes

  1. 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 1.0.4.9), 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.

Secondary outcomes

  1. 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.

  2. 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.

  3. 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).

Sponsors and collaborators

Lead sponsor

Hospices Civils de Lyon

Other

Registry information

Official study title

Microcirculatory Effects of Methylene Blue in Vasoplegic Shock After Cardiopulmonary Bypass: a Pilot Study

Acronym: MAGIC BLUE

Important dates

Study start
2017
Primary completion
2017
Study completion
2019
First posted
Jan 31, 2020
Registry last updated
Jan 31, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.