The Impact of Intra-operative Fluid Infusion Rate on Microcirculation

University Hospital Hradec Kralove

Status: Enrolling

Conditions: Hemodilution; Fluid Therapy; Microcirculation

Treatments: Drug: Crystalloid Solutions

Study type: Interventional

Funder types: Other

Identifiers

NCT05606536

CooperatioUK_MIC_HEM

Details and patient eligibility

About

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.

Full 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.

Enrollment: 80 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• elective recumbent and laparoscopic surgery
• informed consent

Exclusion criteria

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

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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80 participants in 4 patient groups

10 % hemodilution

Experimental group

Description:

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

Treatment:

Drug: Crystalloid Solutions

20 % hemodilution

Experimental group

Description:

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

Treatment:

Drug: Crystalloid Solutions

30 % hemodilution

Experimental group

Description:

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

Treatment:

Drug: Crystalloid Solutions

Standart care

No Intervention group

Description:

Infusion rate based upon the standard care.