Acute Kidney Injury After Cardiac Surgery: Novel Ultrasound Techniques for Prediction of Acute Kidney Injury

April 8, 2021 updated by: Johan Fridolf Hermansen, Aarhus University Hospital
Acute Kidney Injury (AKI) is a frequent and important complication to cardiac surgery. This study will evaluate the diagnostic ability of ultrasonographic measures of blood flow in kidneys and liver in predicting AKI after cardiac surgery.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Acute Kidney Injury (AKI) is a frequent and important complication to cardiac surgery. The pathophysiology is multifactorial, but renal functions in this setting is determined by a complex interplay between renal perfusion, fluid status, cardiac output, mean arterial pressure and back pressure to venous outflow.

Renal perfusion may be quantified with novel ultrasound techniques. Ultrasonography of the kidney and renal vasculature allows for assessment of renal afferent flow and renal venous flow and, together with venous flow patterns of the portal vein and liver veins, may identify patients in risk of AKI.

The study is observational and will describe the diagnostic accuracy of the ultrasound measures in predicting postoperative AKI. Patients will be examined with ultrasound of kidney and liver flow along with echocardiography on on the day before surgery and on the 1st and 4th. In addition, patients are followed with markers of kidney function, fluid balance and invasive measures of mean arterial pressure and central venous pressure.

Study Type

Observational

Enrollment (Actual)

150

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Denmark
      • Aarhus, Denmark, 8200
        • Aarhus University Hospital, Department of Anaesthesiology
  • South Africa
      • Johannesburg, South Africa, 2196
        • Department of Anesthesiology, Charlotte Maxeke Johannesburg Academic Hospital, University of the Witwatersrand

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

Patients scheduled for on-pump cardiac surgery at the Department of Cardiothoracic & vascular surgery, Aarhus University Hospital. The study will include 100 patients from Denmark.

Description

Inclusion Criteria:

  • All patients ≥ 18 years
  • Scheduled for on-pump cardiac surgery
  • Oral and written consent

AND

  • 1 of the following risk factors for development of postoperative AKI may be included:

    • age > 70 years;
    • NYHA (New York Heart Association) 3+4;
    • Insulin dependent diabetes;
    • Glomerular filtration rate < 60 ml/min/1,73 m2;
    • Ejection fraction < 35;

    • Surgery:

      • Combined CABG and valve surgery;
      • Any valve surgery except isolated aortic-valve surgery;
      • Redo surgery;
      • Endocarditis;
    • Peripheral vascular disease.

Exclusion Criteria:

  • Insufficient ultrasonographic imaging of the kidneys;
  • Known morphological kidney disease;
  • Preoperative dialysis;
  • Prior participation in the study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Aarhus University Hospital
100 patients undergoing on-pump cardiac surgery at Charlotte Maxeke Johannesburg Academic Hospital, University of the Witwatersrand
Procedure: On-pump cardiac surgery
All participants will undergo on-pump cardiac surgery
Charlotte Maxeke Johannesburg Academic Hospital, University of the Witwatersrand
50 patients undergpoing on-pump cardiac surgery at at Charlotte Maxeke Johannesburg Academic Hospital, University of the Witwatersrand
Procedure: On-pump cardiac surgery
All participants will undergo on-pump cardiac surgery

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The association between the kidney venous ultrasonography flow pattern category on the 1st postoperative day and acute kidney injury (AKI) on the 4th postoperative day.
Time Frame: 4 days

The flow pattern is grouped as either continuous, biphasic or monophasic based on the appearance.The final analysis will possibly include other flow categories.

AKI is defined by the 2012 Kidney Disease: Improving Global Outcomes (KDIGO) criteria and graded in four stages from no AKI to stage 1-3 AKI based on serum creatinin change and/or changes in urine output, with stage 3 being the worst stage.
4 days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation between changes in organ-specific flow measurements and the corresponding biomarkers.
Time Frame: 1 month
Correlations between organ-specific ultrasonography flow measurements and the corresponding biomarkers of kidneys, liver and heart function, for both absolute values of organ-specific flow and perioperative changes in organ-specific flow
1 month
Establishment of the most optimal organ specific cut-off values and the development of AKI.
Time Frame: 1 month

Establishment of the most optimal cut-off (threshold) values for

  • absolute ultrasonography flow values for respectively kidney arterial flow; kidney venous flow; liver vein flow; portal vein flow and the risk of development of AKI.
  • changes in ultrasonography flow values for respectively kidney arterial flow; kidney venous flow; liver vein flow; portal vein flow and the risk of development of AKI.
1 month
Fluid balance and AKI
Time Frame: 1 month
Correlations between accumulated fluid balance on the 1st postoperative day and the development of AKI on the 4th postoperative day.
1 month
Diastolic dysfunction and AKI
Time Frame: 1 month
Correlations between echocardiographic measures of diastolic dysfunction and AKI. The measures include mitral inflow (E and A), mitral annular motion, medial and lateral (e' and a'), and measures define grades of diastolic dysfunction from normal to grade I-III, with grade III being the worst.
1 month
Organ-specific flow measures and mortality
Time Frame: 1 month
Correlation between organ-specific ultrasonography flow measurements on the day before surgery, the 1st and 4th postoperative day and the mortality at the 1st, 4th and 28th postoperative day.
1 month
Organ-specific flow measures and and time of stay in ICU and hospital
Time Frame: 1 month
Correlation between organ-specific ultrasonography flow measurements on the day before surgery, the 1st and 4th postoperative day and the duration of intensive care stay and duration of hospital stay.
1 month

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Aarhus University Hospital

Collaborators

University of Aarhus

Investigators

  • Study Chair: Peter Juhl-Olsen, MD, PhD, Department of Anaesthesiology, Aarhus University Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 15, 2018

Primary Completion (Actual)

March 31, 2020

Study Completion (Actual)

March 31, 2020

Study Registration Dates

First Submitted

October 9, 2018

First Submitted That Met QC Criteria

October 30, 2018

First Posted (Actual)

November 1, 2018

Study Record Updates

Last Update Posted (Actual)

April 13, 2021

Last Update Submitted That Met QC Criteria

April 8, 2021

Last Verified

April 1, 2021

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 1-10-72-267-18

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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