Microcirculation, Photoplethysmography
Conditions
Brief summary
The objective of this observational study is to explore microcirculation in healthy volunteers and in ventilated patients in the operating room and in critical care. The general objective of this study is to evaluate microcirculation with photoplethysmography (PPG) in different pathophysiological situations and to compare PPG with available standard methods. Specifically, evaluate the correlation between the determinations of AC-DC waves obtained by Photoplethysmography (PPG) and those obtained in different dynamic tests in healthy volunteers. To compare microcirculation assessments \[capillary refill time (CRT), perfusion index (PI), perfusion index variability (PIV)\] with measurements obtained by PPG in the context of critically ill patients. To compare microcirculation assessments (CRT, PI PVI) with measurements obtained by PPG in the context of patients on invasive mechanical ventilation (IMV) in the operating room and in critical care.
Detailed description
An attempt is made to explore different physiological aspects that affect microcirculation such as vascular tone and blood volume. Photoplethysmography usually examines the AC wave equivalent to the pulsatile wave, however the DC component has been less explored and can account for the microcirculation and volemia status of the subjects. Since there is no gold standard, it will be compared against different validated methods.
Interventions
OTHERphotoplethysmography
Photoplethysmography (BluePoint, Frankfurt, Germany) is the pulse wave measured by a pulse oximeter. It is obtained based on the absorbance of red/infrared light in a given tissue. The signal is made up of two components: 1) the alternating component (AC), which is the pulse wave itself, which is determined by the absorbance of pulsatile arterial blood. 2) The continuous component (DC), which represents the absorbance of venous blood and the rest of the tissues. Within these tests the investigators find vascular occlusion, elevation of the legs, raising or lowering the tested hand above/below the phlebostatic level, cold/heat test, etc. Each of them evaluates different aspects of circulation such as endothelial function, myogenic response to blood flow, perfusion pressure, autonomic reflexes, preload-dependence, or venous flow among other aspects of microcirculation.
Sponsors
Hospital Privado de Comunidad de Mar del Plata
Study design
Observational model
OTHER
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Healthy Volunteers: Inclusion Criteria: * Written informed consent. * Age \> 18 years.
Exclusion criteria
* Pregnancy. * Smokers. * Respiratory and/or cardiovascular pathologies. * Peripheral vascular disease. Operation room or Critical care Unit patients Inclusion criteria: * Written informed consent. * Age \> 18 years. * Critical patients ventilated in the ICU of any origin.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| variations in AC signal of photoplethysmography | Through study completion, an average of 1 year | Changes in the AC wave of photoplethysmography (it does not currently have standardized measurement units) will be evaluated in each functional test (CRT, LPR, venous occlusion test, progressive arterial occlusion test). It will be treated as a continuous numerical variable. |
| variations in DC signal of photoplethysmography | Through study completion, an average of 1 year | Changes in the DC wave of photoplethysmography (it does not currently have standardized measurement units) will be evaluated in each functional test (CRT, LPR, venous occlusion test, progressive arterial occlusion test). It will be treated as a continuous numerical variable. |
Countries
Argentina
Contacts
Primary ContactNora Fuentes, PhD
Backup ContactGerarado Tusman, MD
Outcome results
None listed