Prediction of the Effect of Fluid Administration Using Arterial Pressure and Ventilator Data During Abdominal Surgery

Fluid Responsiveness Prediction Using Pulse Pressure Variation - Integrating Ventilator Settings

It is well known, that patients with circulatory impairment sometimes, but not always, benefit from intravenous fluids. Predicting if a fluid administration will improve circulation is therefore of substantial clinical interest.

Ventilator treatment induces cyclic variation in blood pressure due to interaction between the lungs and the heart. This variation is minor, but its amplitude may be used for guiding fluid administration.

However, this method of using ventilator-induced variation in blood pressure to predict the effect of fluid administration was developed when different settings for ventilator treatment was recommended, compared with today. With today's recommend ventilator treatment, the method is, unfortunately, less reliable.

The investigators will investigate how different ventilator settings influence variation in blood pressure, and the investigators will test if this knowledge allows us to better predict the effect of a fluid administration, by taking the ventilator settings into account.

Study Overview

• Status: Completed
• Conditions: Fluid Overload; Hypovolemia
• Intervention / Treatment: Other: Series of ventilator settings

• Study Type: Observational
• Enrollment (Actual): 52

Contacts and Locations

Study Locations

• Denmark
  • Aarhus N, Denmark, 8200
    • Aarhus University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients at department of abdominal surgery, Aarhus University Hospital, scheduled for open abdominal surgery with planned use of Aarhus University Hospital's goal-directed therapy protocol (hemodynamic monitoring).

Description

Inclusion Criteria:

• Scheduled open abdominal surgery.
• Scheduled treatment with Aarhus University Hospital's goal-directed therapy protocol (hemodynamic monitoring).

Exclusion Criteria:

• Left ventricular ejection fraction ≤ 40 %
• Irregular heart rhythm (e.g. atrial fibrillation or frequent ectopic beats)
• Known right ventricular dysfunction (if reported qualitatively in pre-operative assessment or objectively via Tricuspid Annular Plane Systolic Excursion (TAPSE) < 17 mm)
• Pregnancy
• Prior participation in this study

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Patients undergoing open abdominal surgery

Other: Series of ventilator settings; Before a planned fluid administration, the investigators will apply a series of 10 ventilator settings for 30 seconds each. The settings are the following combinations of respiratory rate (RR) and tidal volume (TV): RR (min^-1), TV (ml/kg predicted body weight) 31, 6 31, 8 24, 6 24, 8 17, 6 17, 8 10, 4 10, 6 10, 8 10, 10 (the order of the respiratory rates: 17 to 31, will be randomized. 10/min will always be last. Tidal volume is always applied from lowest to highest for each respiratory rate).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
>10% Increase in stroke volume from before to after a fluid bolus. (Fluid responsiveness)	A patient is considered a fluid responder if they have a >10% increase in stroke volume (pulse contour analysis by the Edwards EV1000 with a FloTrac sensor). Pre-fluid stroke volume is calculated as the median stroke volume estimate in the two minutes immediately preceding the fluid bolus. Post-fluid stroke volume is calculated as the median stroke volume estimate in the two minutes immediately following the fluid bolus. Change in stroke volume is calculated as: 100% * (Post-fluid stroke volume - Pre-fluid stroke volume) / Pre-fluid stroke volume	From two minutes before to two minutes after a fluid administration.

Collaborators and Investigators

• Sponsor: University of Aarhus
• Collaborators: Aarhus University Hospital

Study record dates

Study Major Dates

• Study Start (Actual): May 15, 2020
• Primary Completion (Actual): June 29, 2021
• Study Completion (Actual): June 29, 2021

Study Registration Dates

• First Submitted: March 2, 2020
• First Submitted That Met QC Criteria: March 5, 2020
• First Posted (Actual): March 6, 2020

Study Record Updates

• Last Update Posted (Actual): July 16, 2021
• Last Update Submitted That Met QC Criteria: July 15, 2021
• Last Verified: April 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Hypovolemia
• Other Study ID Numbers: 1-10-72-245-19

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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