Clinical trial NCT05990907: Influence of RIC on the Orthostatic Competence of the Microcirculation
Official title: Pilot Study: Influence of Ischemic Preconditioning on the Orthostatic Competence of the Microcirculation in the Lower Extremity
Study type: INTERVENTIONAL
Overall status: ACTIVE_NOT_RECRUITING
Phase: NA
Conditions: Microcirculation
Orthostatic Intolerance
Remote Ischemic Preconditioning
Hemodynamics
Keywords: Microcirculation
Remote ischemic preconditioning
Lead sponsor: ISAR Klinikum
Sponsor class: OTHER
First posted: 2023-08-14
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Intervention model description: The research project is a controlled, single-arm, monocentric clinical study. Due to the study design, randomization and blinding are not possible.

Unfortunately, there is no scientific data on how long the effects of ischemic preconditioning last. Thus, in a cross-over design study with protocols 1 and 2 in a different order, there would be a risk or bias that subjects who received ischemic preconditioning in the first measurement would have this effect in the second measurement. For this reason, we decided on a standardized procedure for measurement 1 (without ischemic preconditioning) and measurement 2 (with ischemic preconditioning). In this case, the study design would be one-armed.
Primary purpose: PREVENTION

Brief summary: The goal of this clinical trial (pilot study) is to learn about the microcirculatory regulation of the lower extremity under orthostatic stress with and without RIC - Remote Ischemic Preconditioning in healthy participants. The main question it aims to answer are:

Do the beneficial effects of RIC withstand orthostatic stress? / Does RIC benefit lower extremity microcirculation in ortho-statically stressed subjects? Is there a relationship/correlation between the variables of microcirculation and hemodynamics in the context of RIC and orthostatic loading?

Detailed description: The use of free flaps is a standard procedure in reconstructive plastic surgery, in which a wide variety of tissue units are microsurgically transplanted, often to cover defects on the body surface. Microvascular tissue transplants depend on an adequate blood supply, which is particularly vulnerable in the first postoperative phase. In the case of reconstructions of the lower extremities in particular, the flap perfusion is stressed during the first mobilizations due to the orthostatic load. For this reason, the mobilization of the patients is gradually increased from day to day with precise monitoring of the blood flow (so-called flap training).

A procedure for temporarily improving the blood flow in free flaps is ischemic preconditioning (RIC - Remote Ischemic Preconditioning). Repeated, short cycles of ischemia/reperfusion applied to a circumscribed vascular territory (e.g. supra systolic tourniquet arm) lead to an increase in tissue perfusion, even outside the area of application (arm).

RIC could have the potential to optimize the tissue perfusion of flaps even under orthostatic stress and to promote an earlier mobilization of patients. Our work investigates the influence of RIC on orthostatic competence (as part of a standardized orthostatic load with a tilting table) of the microcirculatory system in the lower extremities and the orthostatic hemodynamic regulation itself.

Eligibility criteria: Inclusion Criteria:

* Non-smokers
* No diseases relevant to circulation and blood flow (arterial hypertension, peripheral arterial occlusive disease, chronic venous insufficiency)
* Subjects must be capable of insight. Anyone who can understand the nature, significance, and scope of the clinical trial and determine their will accordingly is capable of insight.

Exclusion Criteria:

* Non-consent
* Lack of compliance
* Syncope tendency

Primary outcomes:
measure: Microcirculation parameters
timeFrame: continuous measurement; Focus on the following periods: 1 minute before RIC, 1 min before the tilting table, half-time minute in the upright position, 1 min before the end of the measurment
Secondary outcomes:
measure: Microcirculation parameters - oxygen saturation
timeFrame: continuous measurement; Focus on the following periods: 1 minute before RIC, 1 min before the tilting table, half-time minute in the upright position, 1 min before the end of the measurment
measure: Microcirculation parameters - Relative amount of hemoglobin
timeFrame: continuous measurement; Focus on the following periods: 1 minute before RIC, 1 min before the tilting table, half-time minute in the upright position, 1 min before the end of the measurment
measure: Hemodynamics
timeFrame: continuous measurement; Focus on the following periods: 1 minute before RIC, 1 min before the tilting table, half-time minute in the upright position, 1 min before the end of the measurment
measure: Hemodynamics
timeFrame: continuous measurement; Focus on the following periods: 1 minute before RIC, 1 min before the tilting table, half-time minute in the upright position, 1 min before the end of the measurment
measure: Hemodynamics
timeFrame: continuous measurement; Focus on the following periods: 1 minute before RIC, 1 min before the tilting table, half-time minute in the upright position, 1 min before the end of the measurment
measure: Hemodynamics
timeFrame: continuous measurement; Focus on the following periods: 1 minute before RIC, 1 min before the tilting table, half-time minute in the upright position, 1 min before the end of the measurment
Other outcomes:
Locations:
city: Munich
country: Germany
facility: ISAR Klinikum
state: Bavaria
Study officials:
affiliation: Department Plastic Surgery ISAR Klinikum, Munich
name: Ulf Dornseifer, MD, PhD
role: STUDY_CHAIR
References: