Evaluation of Microcirculation With Photoplethysmography (Pulse Oximetry) in Healthy Volunteers and Ventilated Patients

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.

Study Overview

• Status: Recruiting
• Conditions: Microcirculation; Photoplethysmography
• Intervention / Treatment: Other: photoplethysmography

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.

• Study Type: Observational
• Enrollment (Estimated): 20

Contacts and Locations

• Study Contact: Name: Nora Fuentes, PhD; Phone Number: +542234370088; Email: nora.fuentes@hospitalitaliano.org.ar
• Study Contact Backup: Name: Gerarado Tusman, MD; Email: gtusman@hotmail.com

Study Locations

• Argentina
  • Buenos Aires
    • Mar Del Plata, Buenos Aires, Argentina, 7600
      • Recruiting
      • Hospital Privado De Comunidad
      • Contact: Nora Fuentes, PhD; Phone Number: +5492234370088; Email: nora.fuentes@hospitalitaliano.org.ar

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

healthy volunteers or operating room or intensive care patients- See inclusion and exclusion criteria

Description

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.

Exclusion criteria:

• Known peripheral vascular disease.
• Burns on both upper limbs.
• Trauma to both upper limbs.

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Healthy volunteers; >18 years old healthy	Other: photoplethysmography; 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 we 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.
Patients in critical care unit; patient in ICU with requirement for hemodynamic monitoring	Other: photoplethysmography; 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 we 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.
Patients with ventilatory support in the operating room or critical care unit; patient in the ICU or operating room with a requirement for hemodynamic monitoring and ventilatory support	Other: photoplethysmography; 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 we 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
variations in AC signal of photoplethysmography	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.	Through study completion, an average of 1 year
variations in DC signal of photoplethysmography	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.	Through study completion, an average of 1 year

Collaborators and Investigators

• Sponsor: Hospital Privado de Comunidad de Mar del Plata
• Investigators: Principal Investigator: Nora Fuentes, PhD, Hospital Privado De Comunidad

Study record dates

Study Major Dates

• Study Start (Actual): June 19, 2023
• Primary Completion (Estimated): June 1, 2025
• Study Completion (Estimated): June 1, 2025

Study Registration Dates

• First Submitted: November 10, 2023
• First Submitted That Met QC Criteria: November 15, 2023
• First Posted (Actual): November 21, 2023

Study Record Updates

• Last Update Posted (Actual): November 21, 2023
• Last Update Submitted That Met QC Criteria: November 15, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: UCI-000004

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No