Assessing Fluid Responsiveness With PWTT

Finding the Cut-off Value of Pulse Wave Transit Time (PWTT) to Estimate the Fluid Responsibility

Pulse wave Transit time (PWTT) is a parameter calculated from ECG and pulseoximeter. It is supposed to help assessing the preload Status and guide intraoperative fluid therapy. This Project aims to validate the benefit of PWTT assessment in an observational clinical fluid study. In case of hypovolemia, patients will receive a fluid Bolus and hemodynamic data from clinical Standard Monitoring, esophageal doppler and PWTT will be recorded before and after the fluid Bolus. Receiver operating characteristic (ROC) curve will be used to determine the validity of PWTT as indicator for fluid responsiveness and its cut off value.

Study Overview

• Status: Completed
• Conditions: Fluid Therapy; Monitoring, Intraoperative
• Intervention / Treatment: Diagnostic test: Assessing fluid responsiveness by PWTT value

Detailed Description

PWTT is determined by measuring the beginning and the end of pulse wave duration and can be calculated as the time interval from the ECG R-wave peak to the rise point of the pulse oximeter wave.

it consists of two components: pre ejection period (PEP) and arterial pulse wave transit time (a-PWTT). PEP is defined as the time from the ECG R wave to the rise point of the aortic root pressure wave. a-PWTT is defined as the time from the rise point of the aortic pressure wave to the rise point of the pulse oximeter wave. a-PWTT is the component which is directly related to the velocity of the pulse wave. However noninvasively, we can measure only PWTT, which also includes PEP. In general, PEP change over short periods of time is negligible in most cases, so we can assume that PWTT corresponds to

a-PWTT. In studies using several studies using animals and healthy volunteers, PWTT showed good correlation with stroke volume or systolic blood pressure. Also in experimental and clinical setting, it is shown that PEP changes indicate change in preloads.

It is not known at this moment, which of the following factors to be considered in processing raw data to acquire accurate PWTT value on predicting fluid responsiveness.

1. The beginning of pulse wave can be assessed by the appearance of either Q wave, which represents the initial phase of depolarisation going through the interventricular septum or R wave, which represents the ventricular depolarisation in ECG.
2. The end of pulse wave duration can be assessed by peripheral plethysmography mostly from a finger tip but also from an ear lobe.
3. The pulse wave time can be simply measured as it is, but can also be adjusted by heart rate using Bazett-Formula.
4. Not only the simple PWTT but also ventilatory induced fluctuation of PWTT (ΔPWTT) may be used for predicting fluid responsiveness.

• Study Type: Observational
• Enrollment (Actual): 38

Contacts and Locations

Study Locations

• Germany
  • Rheinland-Pfalz
    • Mainz, Rheinland-Pfalz, Germany, 55131
      • University Medical Center of Johannes Gutenberg University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients who are scheduled for elective open abdominal surgery

Description

Inclusion Criteria:

• Adults 18 - 80 years old
• elective open abdominal surgery
• clinical indication for direct arterial blood pressure Monitoring
• supine Position intraoperatively

Exclusion Criteria:

• under 18 years, over 80 years old
• pregnant
• no informed consent
• systemic inflammatory response syndrome (SIRS) or Sepsis
• Severe cardiac, coronary or vascular disease
• Arrythmia
• Cardiac valves anomaly
• BMI > 35
• American Society of Anesthesiologists (ASA) physical status classification system: 4
• Lung disease that excludes Ventilation with a tidal volume >8ml/kg
• esophageal pathology
• planned prone position surgery

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Only
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
PWTT change before and after fluid bolus	PWTT recorded before and 1 minute after fluid bolus of 7ml/kg intraoperatively. PWTT values will be calculated: defining PWTT start by either Q-wave or R-wave, defining PWTT end at arrival of the plethysmographic signal either at the finger tip or at the ear lobe, defining PWTT length by either simple measurement or adjusted by the Bazett-Formula. Additionally, as a dynamic parameter respiratory variation of PWTT (ΔPWTT) will be computed.	1 day

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Heart rate before and after fluid bolus	Heart rate (in beats per minute), derived from intraoperative standard monitoring. This hemodynamic parameter will be measured before and 1min after fluid bolus.	1 day
Blood pressure before and after fluid bolus	Systolic blood pressure/diastolic blood pressure/mean arterial pressure (in millimeters of mercury), derived from intraoperative standard monitoring. This hemodynamic parameter will be measured before and 1min after fluid bolus.	1 day
Flow Time corrected before and after fluid bolus	Flow Time corrected (in milliseconds) measured by esophageal doppler. This hemodynamic parameter will be measured before and 1min after fluid bolus.	1 day
Stroke volume before and after fluid bolus	Stroke volume (in milliliters per heartbeat) measured by esophageal doppler. This hemodynamic parameter will be measured before and 1min after fluid bolus.	1 day
Pulse Pressure Variation before and after fluid bolus	Pulse Pressure Variation (as percentage) assessed using arterial pressure monitoring. This hemodynamic parameter will be measured before and 1min after fluid bolus.	1 day

Collaborators and Investigators

• Sponsor: Johannes Gutenberg University Mainz
• Investigators: Principal Investigator: Kimiko Fukui-Dunkel, M.D., Ph.D., University Medical Center of Johannes Gutenberg University

Publications and helpful links

General Publications

• Rhodes A, Cecconi M, Hamilton M, Poloniecki J, Woods J, Boyd O, Bennett D, Grounds RM. Goal-directed therapy in high-risk surgical patients: a 15-year follow-up study. Intensive Care Med. 2010 Aug;36(8):1327-32. doi: 10.1007/s00134-010-1869-6. Epub 2010 Apr 8.

Study record dates

Study Major Dates

• Study Start (Actual): May 31, 2016
• Primary Completion (Actual): December 31, 2018
• Study Completion (Actual): January 31, 2019

Study Registration Dates

• First Submitted: April 25, 2017
• First Submitted That Met QC Criteria: September 12, 2017
• First Posted (Actual): September 13, 2017

Study Record Updates

• Last Update Posted (Actual): July 30, 2020
• Last Update Submitted That Met QC Criteria: July 29, 2020
• Last Verified: July 1, 2020

More Information

Terms related to this study

• Other Study ID Numbers: 837.004.16

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