Ultrasound Assessment of Volume in Patients on Continuous Dialysis

Renal failure and resuscitation measures in critically ill patients can result in fluid overload. Fluid overload in renal failure patients can cause harmful effects like pulmonary edema, anasarca and congestive cardiac failure exacerbations among other complications. These have been associated with increased time on the ventilator, increased length of stay in the ICU, and higher overall mortality for patients requiring dialysis in the ICU.

The current standard of care for adjusting fluid removal rates in patients on continuous renal replacement therapy relies on clinical judgement. Clinicians take into account factors like the patient's condition, vasopressor requirements, kidney function, total intake and outputs, vital signs, and physical examination findings when making daily changes to fluid removal rates on dialysis machines. Such assessment is highly subjective and can be imprecise/inaccurate leading to hypotension and hemodynamic instability in a critically ill patient.

Use of conventional ultrasound by physicians to assess volume status using compressibility of the inferior vena cava has been shown to be a reliable predictor of volume status and can help guide therapy. Such use makes bedside volume assessment a non-invasive, rapid, repeatable point of care tool that can provide objective data to guide fluid removal determine velocity of fluid removal and help identify patients at risk of hypotension and hemodynamic instability during the process of fluid removal. Apart from rare possible local allergic reactions to ultrasound jelly and transient local discomfort, the disadvantages are minimal. Ultrasonography has been considered a safe imaging modality. This protocol will measure inferior vena cava compressibility using the General Electric VScan with Dual Probe, which has FDA approval for abdominal and vascular imaging in humans.

Study Overview

• Status: Completed
• Conditions: Respiratory Failure; Kidney Failure; Volume Overload
• Intervention / Treatment: Other: Share ultrasound measurement of IVC collapsibility to Nephrology Attending; Other: Do not share ultrasound measurement of IVC collapsibility to Nephrology Attending

Detailed Description

The study consists of gathering patient data from the chart and performing ultrasound measurements of inferior vena cava compressibility at the start of continuous renal replacement therapy (CRRT) in patients on the mechanical ventilator in the ICU. Ultrasound measurements on the abdomen, as well as recording of clinical data like intake/output, weight, pulse pressure variability, vasopressor requirement, nutrition requirement, ventilator settings, CRRT settings, and certain laboratory data will be performed at the start of the study and then daily for the next 3 days. On the 3rd day, 50 mL of dialysis waste fluid will be collected and stored for future analysis.

At the start of the study, participants will be randomized to two groups. Study activities are identical between the two groups and both groups receive ultrasound measurements on the abdomen. However, in one group the attending nephrologist on the Acute Consult service will be provided with inferior vena cava compressibility measurement information each day before the start of rounds. Randomization will follow a predefined schedule, known only to the research coordinator, Laura Latta. At no time will the attending physicians receive the ultrasound measurements for the group randomized to not have their data shared.

In addition, the resident, fellow, and attending on the Acute Consult service will be asked to assess the volume status of each participant at the start of the study and then daily for next 3 days. The volume assessment will consist of answering the following question, "Would you recommend fluid removal in this patient today (Yes/No/Unsure)?" The question will be asked verbally by Dr. Narasimha Krishna. Each individual's level of training (post-graduation year) and the response will be recorded. Individual names will not be recorded and responses will not be shared with the attending. Responses to this question are not anticipated to affect management of the participant.

During the follow up phase, the electronic medical records will be checked at day 7 and day 30 to determine if the participant is still in the intensive care unit, is still on the ventilator, or is still alive, or still in the hospital. Both groups will have the same follow up time.

Primary outcome measures include: 1) Time to extubation; 2) Length of ICU stay; 3) Length of hospital stay; and 4) 30 day mortality.

Secondary outcome measures include: 1) Difference in net fluid removal by CRRT at day 3 between the 2 groups; 2) Agreement between volume assessment and inferior vena cava compressibility by level of training.

• Study Type: Interventional
• Enrollment (Actual): 6
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Alabama
    • Birmingham, Alabama, United States, 35294
      • UAB University Hospital

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Acute kidney injury requiring initiation of continuous renal replacement therapy
• Respiratory failure requiring mechanical ventilation

Exclusion Criteria:

• cirrhosis of liver
• pregnant woman
• abdominal surgery interfering with placement of ultrasound probe
• end-stage kidney disease

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Share Data	Other: Share ultrasound measurement of IVC collapsibility to Nephrology Attending; Nephrology attending will be provided with the respiratory variability of IVC diameter as a percent, in addition to a predefined cutoff for responsiveness to volume resuscitation of < 12%. The information will be provided before rounds and before the attending sets the fluid removal goals on dialysis for that day.
Active Comparator: Do Not Share Data	Other: Do not share ultrasound measurement of IVC collapsibility to Nephrology Attending; Respiratory variability of IVC diameter will be measured, but the measurement result will not be shared with the treating team.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to extubation	Length of time the participant is intubated from the start of the study up until the 30 day chart follow up.	Start of study to up to 30 days
Length of ICU stay	Length of time the participant remains in the ICU from the start of the study up until chart follow up at 30 days.	Start of study to up to 30 days
Length of hospital stay	Length of time the participant remains in the hospital up until the 30 day chart follow up.	Start of study to up to 30 days
30 day mortality		Start of study to day 30

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difference in net fluid removal by CRRT at day 3	As measured by documented total intake and output	Start of study to day 3
Agreement between volume assessment and inferior vena cava collapsibility by level of training.	As measured by a kappa statistic between a yes/no question and a predefined IVC collapsibility threshold for fluid removal.	Start of study to day 3

Collaborators and Investigators

• Sponsor: University of Alabama at Birmingham
• Investigators: Principal Investigator: Eric Judd, MD, University of Alabama At Birmingham

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2016
• Primary Completion (Actual): September 7, 2023
• Study Completion (Actual): September 7, 2023

Study Registration Dates

• First Submitted: June 13, 2017
• First Submitted That Met QC Criteria: June 19, 2017
• First Posted (Actual): June 21, 2017

Study Record Updates

• Last Update Posted (Actual): September 8, 2023
• Last Update Submitted That Met QC Criteria: September 7, 2023
• Last Verified: September 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Respiration Disorders; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Respiratory Insufficiency; Renal Insufficiency
• Other Study ID Numbers: F160407004

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