The Impact of Intra-operative Fluid Infusion Rate on Microcirculation

The Impact of Intra-operative Fluid Infusion Rate on Hemodilution and Microcirculation Prospective Observational Pilot Study

Intraoperative fluid therapy (IFT) is an integral part of anesthesia care during surgery. Its main indication is the optimization of oxygen supply to the tissues. For elective surgery that is not associated with higher blood loss and a long period of preoperative fasting, including fluids IFT is dosed to cover the basal daily need for fluids. However, it is not clear whether this fluid dose is optimal. Surgery is a stress factor that leads, among other things, to damage of the endothelial glycocalyx (EG). EG binds a significant amount of plasma, which is released during EG destruction and causes relative hemodilution.

Isovolumic hemodilution is an established intraoperative procedure that serves to better control bleeding in procedures where bleeding is expected. However, partial hemodilution occurs even with standard IFT, and even when fluids are hardly given at all. Flow parameters in microcirculation have not yet been described depending on IFT conduction. The parameters of the microcirculation reflect its functioning, which will consequently affect the postoperative phase of the patient's moaning and clinical outcome.

Study Overview

• Status: Recruiting
• Conditions: Fluid Therapy; Microcirculation; Hemodilution
• Intervention / Treatment: Drug: Crystalloid Solutions

Detailed Description

Intraoperative fluid therapy (IFT) is an integral part of anesthesia care during surgery. Its main indication is the optimization of oxygen supply to the tissues. IFT is tailored to the surgical performance, blood loss, and patient (comorbidities, length of preoperative fasting, hydration level, volemia status). For elective surgery that is not associated with higher blood loss (< 200 ml) and a long period of preoperative fasting, including fluids (fluids per os < 2 hours before the procedure), IFT is dosed to cover the basal daily need for fluids (approx. 1-2 ml) /kg.hour-1). However, it is not clear whether this fluid intake is optimal. Surgery is a stress factor that leads, among other things, to damage of the endothelial glycocalyx (EG), which is a thin carbohydrate layer on the endoluminal side of endothelial cells, which is of fundamental importance for the physiology of microcirculation and tissue metabolism. EG also binds a significant amount of plasma (estimated up to 1.7 liters), which is released during EG destruction and causes relative hemodilution.

Isovolumic hemodilution is an established intraoperative procedure that serves to better control bleeding in procedures where bleeding is expected (e.g. cardiac surgery using an extracorporeal circuit or vascular surgery). However, partial hemodilution occurs even with standard IFT, and even when fluids are hardly given at all. Flow parameters in microcirculation have not yet been described depending on IFT conduction. The parameters of the microcirculation reflect its functioning, which will consequently affect the postoperative phase of the patient's moaning and clinical outcome.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: David Astapenko, MD, PhD; Phone Number: +420495833218; Email: david.astapenko@fnhk.cz

Study Locations

• Czechia
  • Hradec Kralove, Czechia, 50005
    • Recruiting
    • University hospital Hradec Králové
    • Contact: David Astapenko, MD, PhD; Phone Number: +420495833218; Email: david.astapenko@fnhk.cz

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• elective recumbent and laparoscopic surgery
• informed consent

Exclusion Criteria:

• blood loss over 250 ml
• hemodynamic instability requiring noradrenaline infusion

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 10 % hemodilution; Recumbent surgery: infusion rate in first 20 minutes: 15 ml/kg/h; infusion rate after 20 minutes: 2,6 ml/kg/h Laparoscopic surgery: infusion rate in first 20 minutes: 16 ml/kg/h; infusion rate after 20 minutes: 0,8 ml/kg/h	Drug: Crystalloid Solutions; Locally approved crystalloid solution will be given at the predefined infusion rate
Experimental: 20 % hemodilution; Recumbent surgery: infusion rate in first 20 minutes: 26 ml/kg/h; infusion rate after 20 minutes: 3,4 ml/kg/h Laparoscopic surgery: infusion rate in first 20 minutes: 28 ml/kg/h; infusion rate after 20 minutes: 1,6 ml/kg/h	Drug: Crystalloid Solutions; Locally approved crystalloid solution will be given at the predefined infusion rate
Experimental: 30 % hemodilution; Recumbent surgery: infusion rate in first 20 minutes: 38 ml/kg/h; infusion rate after 20 minutes: 5,1 ml/kg/h Laparoscopic surgery: infusion rate in first 20 minutes: 44 ml/kg/h; infusion rate after 20 minutes: 2,4 ml/kg/h	Drug: Crystalloid Solutions; Locally approved crystalloid solution will be given at the predefined infusion rate
No Intervention: Standart care; Infusion rate based upon the standard care.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sublingual microcirculation profile	During one hour four measurements each 20 minutes will take place. Recordings will be assessed automatically by specialised software. Microcirculatory parameters of interest are: capillary density, De Backer score, perfused capillary density and proportion of perfused vessels. Capillary density comes in mm/mm2 and the higher number the better, there is not approved median number. De Backer score is derived from capillary density and it is without dimension. Perfused capillary density signifies a percent of perfused vessels and it is in %. Normal values in healthy adults are around 90 %.	1 hour

Collaborators and Investigators

• Sponsor: University Hospital Hradec Kralove

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2022
• Primary Completion (Estimated): December 31, 2025
• Study Completion (Estimated): December 31, 2025

Study Registration Dates

• First Submitted: October 26, 2022
• First Submitted That Met QC Criteria: October 31, 2022
• First Posted (Actual): November 4, 2022

Study Record Updates

• Last Update Posted (Actual): March 27, 2025
• Last Update Submitted That Met QC Criteria: March 24, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Other Study ID Numbers: CooperatioUK_MIC_HEM

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No