Ignite Creation Date:
2024-05-06 @ 5:23 PM
Last Modification Date:
2024-10-26 @ 2:27 PM
Study NCT ID:
NCT05285514
Status:
RECRUITING
Last Update Posted:
2023-04-27
First Post:
2022-03-09
Brief Title:
Macro- and Microcirculation Crosstalk in Brain-damaged Patients Under Anesthesia or in Intensive Care
Sponsor:
Assistance Publique - Hôpitaux de Paris
Organization:
Assistance Publique - Hôpitaux de Paris
Study Overview
Official Title:
Analysis of the Macro-microcirculatory Coupling in the Course of Using the Vasoactive Substances During Anesthesia-resuscitation of Brain-damaged Patients
Status:
RECRUITING
Status Verified Date:
2023-04
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
MICRONOR
Brief Summary:
In patients with severe brain injury maintenance and control of blood pressure is at the very first point in the management strategy whether in anesthesia or in intensive care In order to restore cerebral perfusion pressure CPP to appropriate levels 60-70 mmHg while ensuring optimal perfusion of other vital organs intravenous administration of vasodilator inodilator or vasoconstrictor vasoactive agents is commonly used
These vasoactive agents widely used to correct hypotension or hypertension have their own effects on the load conditions of the left ventricle and the tone of the arterial tree but also have effects on the microcirculation
The microcirculatory status of a tissue cannot be reliably predicted by considering only the macrocirculatory parameters usually measured
Therefore in situations where organ perfusion is inadequate or compromised patient management that includes the integration of the impact of vasoactive agents on the microcirculation seems essential for comprehensive hemodynamic treatment
The non-invasive study of microcirculatory perfusion and its interactions with the macrocirculatory network using a minimally invasive method such as videomicroscopy should allow a better use of the treatments used
For cerebral patients routine management already includes very complete monitoring of all cardiopulmonary and cerebral systemic parameters
It is therefore imperative to study and propose new minimally invasive modalities for monitoring the microcirculation in order to define new therapeutic targets that take into account the microcirculatory compartment
These vasoactive agents widely used to correct hypotension or hypertension have their own effects on the load conditions of the left ventricle and the tone of the arterial tree but also have effects on the microcirculation
The microcirculatory status of a tissue cannot be reliably predicted by considering only the macrocirculatory parameters usually measured
Therefore in situations where organ perfusion is inadequate or compromised patient management that includes the integration of the impact of vasoactive agents on the microcirculation seems essential for comprehensive hemodynamic treatment
The non-invasive study of microcirculatory perfusion and its interactions with the macrocirculatory network using a minimally invasive method such as videomicroscopy should allow a better use of the treatments used
For cerebral patients routine management already includes very complete monitoring of all cardiopulmonary and cerebral systemic parameters
It is therefore imperative to study and propose new minimally invasive modalities for monitoring the microcirculation in order to define new therapeutic targets that take into account the microcirculatory compartment
Detailed Description:
In patients with severe brain injury maintenance and control of blood pressure is at the primary focus of the management strategy in both anesthesia and intensive care In order to restore cerebral perfusion pressure CPP to appropriate levels 60-70 mmHg while ensuring optimal perfusion of other vital organs intravenous administration of vasodilator ino-dilator or vasoconstrictor agents is widely used
These vasoactive agents widely used to correct hypotension or hypertension have their own effects on left ventricular loading conditions arterial tree tone but also effects on microcirculation
Currently the vast majority of anaesthesias and organ resuscitations are carried out from a macrocirculatory view of the system Hemodynamic optimization is then based on the monitoring of macrocirculatory parameters such as arterial pressure and sometimes cardiac output coupled with parameters of adequacy of tissue oxygenation arterial and venous O2 saturation
The microcirculatory status of a tissue cannot be reliably predicted by considering only the usually measured macrocirculatory parameters Peripheral capillary perfusion pressure is the result of the coupling between peripheral microcirculatory tone and resistance and macrocirculatory impedance
The response of microvessels to the various vasoactive agents widely used in the clinic has been little studied
However it should be noted that excessive use of vasoconstrictor amines particularly in the presence of hypovolemia may paradoxically to the macrocirculatory impression induce closure of the capillary network and aggravate tissue ischemia This capillary de-recruitment is due in particular to the dissipation of pressure in the systemic arterial system due to the excessively high peripheral resistances and fatally leads to a rarefaction of the open capillaries
In addition the increased macrocirculatory impedance imposes a myocardial workload that may cause a decrease in cardiac output amplifying the tissue damage This leads to a new situation of uncoupling characterized by decreased macrocirculatory flow and elevated microcirculatory resistance
This is why in situations where organ perfusion is inadequate or weakened patient management that includes the integration of the impact of vasoactive agents on the microcirculation seems essential for global hemodynamic treatment
Impaired microcirculation is a key pathophysiological factor in organ failure and death in patients The impact of organ failure renal respiratory cardiac etc on the quality of cerebral oxygenation is major and conditions the brains recovery potential Organ failure by its repercussions on the conditions of brain recovery severely worsens the prognosis of brain damaged patients secondary brain insults of systemic origin SBISOs
In order to recognize and avoid the pitfalls associated with these aortocapillary uncoupling mechanisms specific monitoring of microcirculatory flow and tissue perfusion during the administration of vasoactive agents is largely relevant The major obstacle is the difficulty of studying microcirculatory behavior at the bedside in a non or minimally invasive manner
Direct visualization of the capillary circulation in vivo is now possible using a minimally invasive technique of orthogonal spectral polarization OSP videomicroscopy and more recently Sidestream Dark Field imaging SDF
This last technique validated in humans mainly in septic shock situations uses a polarized light source whose absorbance by hemoglobin and reflection by other tissues allows the construction of a contrasted image This technique allows the visualization of capillary networks on the surface of solid organs covered with a thin epithelial layer to a depth of about 300 µm An analysis of the recorded image assisted by calculation software allows the semi-quantitative calculation of capillary density proportion of perfused vessels PPVSL capillary flow Microcirculatory Flow Index MFISL and heterogeneity heterogeneity index HETSL of these
To date several non-invasive techniques are available each measuring different parameters specific to this microcirculation
Capillary density capillary or tissue flow estimation hemoglobin saturation oxygenation and tissue CO2 pressure measurements
The non-invasive study of microcirculatory perfusion and its interactions with the macrocirculatory network thanks to a minimally invasive method such as videomicroscopy should allow a better use of the treatments used
Overall the trend in anaesthesia and intensive care is increasingly towards individualized management and the use of monitoring macro- and microcirculatory associated with a thorough knowledge of the treatments used vasoconstrictors vasodilators and vascular filling in particular seems to be an essential basis for these considerations
The empirical use of vasoactive agents without specific monitoring of these effects and the unpredictable impact of changes in one of the two compartments on the final state of the system during adequate macrocirculatory resuscitation could even be deleterious at the microcirculatory level
These pathophysiological concepts specific to macromicrocirculation cross-talk demonstrate the imperative of developing monitoring specific to the microvascular network in critical patients
The techniques have evolved and the tools are now available and can be used safely in patients
For brain-damaged patients routine management already includes a very complete monitoring including all systemic cardio-pulmonary and cerebral parameters Participants receive interventions as part of routine medical care to restore Cerebral Perfusion pressure CPP to appropriate levels 60-70 mmHg
The availability of minimally invasive monitoring tools of the microcirculation such as videomicroscopy allows the study of the functional capillary situation according to the vasoactive agent used
The study of microcirculatory perfusion and its interactions with the macrocirculatory network using a minimally invasive method such as videomicroscopy should allow a better use of the treatments used
These vasoactive agents widely used to correct hypotension or hypertension have their own effects on left ventricular loading conditions arterial tree tone but also effects on microcirculation
Currently the vast majority of anaesthesias and organ resuscitations are carried out from a macrocirculatory view of the system Hemodynamic optimization is then based on the monitoring of macrocirculatory parameters such as arterial pressure and sometimes cardiac output coupled with parameters of adequacy of tissue oxygenation arterial and venous O2 saturation
The microcirculatory status of a tissue cannot be reliably predicted by considering only the usually measured macrocirculatory parameters Peripheral capillary perfusion pressure is the result of the coupling between peripheral microcirculatory tone and resistance and macrocirculatory impedance
The response of microvessels to the various vasoactive agents widely used in the clinic has been little studied
However it should be noted that excessive use of vasoconstrictor amines particularly in the presence of hypovolemia may paradoxically to the macrocirculatory impression induce closure of the capillary network and aggravate tissue ischemia This capillary de-recruitment is due in particular to the dissipation of pressure in the systemic arterial system due to the excessively high peripheral resistances and fatally leads to a rarefaction of the open capillaries
In addition the increased macrocirculatory impedance imposes a myocardial workload that may cause a decrease in cardiac output amplifying the tissue damage This leads to a new situation of uncoupling characterized by decreased macrocirculatory flow and elevated microcirculatory resistance
This is why in situations where organ perfusion is inadequate or weakened patient management that includes the integration of the impact of vasoactive agents on the microcirculation seems essential for global hemodynamic treatment
Impaired microcirculation is a key pathophysiological factor in organ failure and death in patients The impact of organ failure renal respiratory cardiac etc on the quality of cerebral oxygenation is major and conditions the brains recovery potential Organ failure by its repercussions on the conditions of brain recovery severely worsens the prognosis of brain damaged patients secondary brain insults of systemic origin SBISOs
In order to recognize and avoid the pitfalls associated with these aortocapillary uncoupling mechanisms specific monitoring of microcirculatory flow and tissue perfusion during the administration of vasoactive agents is largely relevant The major obstacle is the difficulty of studying microcirculatory behavior at the bedside in a non or minimally invasive manner
Direct visualization of the capillary circulation in vivo is now possible using a minimally invasive technique of orthogonal spectral polarization OSP videomicroscopy and more recently Sidestream Dark Field imaging SDF
This last technique validated in humans mainly in septic shock situations uses a polarized light source whose absorbance by hemoglobin and reflection by other tissues allows the construction of a contrasted image This technique allows the visualization of capillary networks on the surface of solid organs covered with a thin epithelial layer to a depth of about 300 µm An analysis of the recorded image assisted by calculation software allows the semi-quantitative calculation of capillary density proportion of perfused vessels PPVSL capillary flow Microcirculatory Flow Index MFISL and heterogeneity heterogeneity index HETSL of these
To date several non-invasive techniques are available each measuring different parameters specific to this microcirculation
Capillary density capillary or tissue flow estimation hemoglobin saturation oxygenation and tissue CO2 pressure measurements
The non-invasive study of microcirculatory perfusion and its interactions with the macrocirculatory network thanks to a minimally invasive method such as videomicroscopy should allow a better use of the treatments used
Overall the trend in anaesthesia and intensive care is increasingly towards individualized management and the use of monitoring macro- and microcirculatory associated with a thorough knowledge of the treatments used vasoconstrictors vasodilators and vascular filling in particular seems to be an essential basis for these considerations
The empirical use of vasoactive agents without specific monitoring of these effects and the unpredictable impact of changes in one of the two compartments on the final state of the system during adequate macrocirculatory resuscitation could even be deleterious at the microcirculatory level
These pathophysiological concepts specific to macromicrocirculation cross-talk demonstrate the imperative of developing monitoring specific to the microvascular network in critical patients
The techniques have evolved and the tools are now available and can be used safely in patients
For brain-damaged patients routine management already includes a very complete monitoring including all systemic cardio-pulmonary and cerebral parameters Participants receive interventions as part of routine medical care to restore Cerebral Perfusion pressure CPP to appropriate levels 60-70 mmHg
The availability of minimally invasive monitoring tools of the microcirculation such as videomicroscopy allows the study of the functional capillary situation according to the vasoactive agent used
The study of microcirculatory perfusion and its interactions with the macrocirculatory network using a minimally invasive method such as videomicroscopy should allow a better use of the treatments used
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| 2021-A02375-36 | OTHER | IDRCB | None |