Fluid Management Study to Evaluate Changes in Intravascular Volume After Applying Various Pressure Levels on the Caval Vein

Study Overview
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Brief Summary
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Fluid therapy optimization in the perioperative period has been considered as major contributor to improve oxygen delivery. A recent, noninvasive approach to estimate fluid requirements in the anesthetized patient with arterial line is the assessment of difference in pulse pressure (dPP). Intraoperative fluid management by dPP is a goal-directed fluid management approach to avoid both hypervolemia and hypovolemia. However, several clinical factors may impede dPP measurements. Surgical manipulations in abdominal procedures may interfere with hemodynamic stability due to obstruction of the caval vein. Physiological considerations make us hypothesize that only intense pressure impedes caval blood flow and thus hemodynamics and dPP. Therefore, the investigators want to assess those changes after standardized application of three different pressure levels (2 N, 5 N, 10 N) on the caval vein.

Official Title
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External Pressure Applied on the Caval Vein and Its Effects on Difference in Pulse Pressure (dPP) and Pleth Variability Index (PVI)

Conditions
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Intravascular Volume, Respiratory Changes

Intervention / Treatment
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* Other: Changes of difference in pulse pressure and plethysmography after applying various pressure levels on the caval vein


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients scheduled for elective hepatic surgery procedures (hemihepatectomy) qualifying for arterial line Exclusion Criteria: pregnancy cardiac insufficiency (NYHA 4, EF < 25 %) coronary (CCS 4) coagulopathy symptoms of infection or sepsis malignant hyperthermia porphyria oesophageal varicose veins absence of sinus rhythm

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: Changes of difference in pulse pressure and plethysmography after applying various pressure levels on the caval vein|Following hepatic resection, a fitting area for pressure application on the caval vein will be identified by the attending surgeon. Baseline assessments of hemodynamic and heart-lung interaction parameters will be taken. Thereafter the surgeon will apply three different pressure levels (2 N, 5 N, 10 N) at random with a force gauge (Fa. ATP Messtechnik, Ettenheim, Germany). Assessment of the parameters will be performed after 2 minutes of pressure application by an investigator, unaware of the pressure applied. After each pressure application 5 minutes will be waited to assure hemodynamic recovery.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of dPP from start of intervention to 2 minutes after start of the intervention |  | Application of pressure for 2 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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fluid management, fluid therapy, dPP, difference in pulse pressure, PVI, pleth variability index, external pressure applied on the caval vein