Kidney Week

Abstract: SA-PO791

Cardiac Output Changes Relate to Ultrafiltration Volume during Intermittent Hemodialysis and to Pre-HD Intravascular Volume Assessed by Inferior Vena Cava Ultrasound Collapsibility in ICU Patients

Session Information

• Standard Hemodialysis for ESRD - I
  November 04, 2017 | Location: Hall H, Morial Convention Center
  Abstract Time: 10:00 AM - 10:00 AM

Category: Dialysis

• 601 Standard Hemodialysis for ESRD

Authors

• Kaptein, Matthew, Loma Linda University Medical Center, Loma Linda, California, United States

Matthew Kaptein,

• Nguyen, Christopher, Keck School of Medicine of USC, Los Angeles, California, United States

Christopher Nguyen,

• Kaptein, John, LAC+USC Medical Center, Los Angeles, California, United States

John Kaptein,

• Kaptein, Elaine, LAC+USC Medical Center, Los Angeles, California, United States

Elaine Kaptein,

Background

The goal of volume management is to optimize intravascular volume and maximize cardiac output (CO).

CO tends to increase after volume administration in volume depleted patients¹, to increase with UF in volume overloaded ESRD patients^2,3, and to decrease with UF in ESRD patients prone to intradialytic hypotension⁴.

Methods

We retrospectively studied 12 ICU patients in 29 intermittent HD (IHD) encounters who had relative intravascular volume assessed by respiratory changes in inferior vena cava diameter within 24 hours prior to IHD/UF, and CO assessed by thermodilution before and after IHD/UF. IVC Collapsibility Index (CI) = (IVCmax-IVCmin)/IVCmax *100%. CO change >10% was considered significant.

Results

For encounters with IVC CI <10% (volume overload), UF -1.6 to -2.6L was associated with increased CO (+14 to +66%) [A]. Larger (-3.0 to -3.2L) [B] or minimal (-0.75 to +0.2L) [C] UF was associated with decreased CO (-15 to -22%). With IVC CI >30% (volume depleted) volume given during IHD may increase CO [D], while UF (-2.4 to -3.0L) may decrease CO (-28 to -44%) [E]. With IVC CI of 10 to 30%, volume removal (-1.4 to -2.8L) may decrease CO (-4 to -20%) [F].

Conclusion

Changes in CO with respect to IVC CI and net volume change with IHD/UF (Fig 1a) may be consistent with changes in position along the Frank Starling curve (Fig 1b), assuming that relative intravascular volume is a primary determinant of IVC CI and CO. These data are consistent with IVC CI being an indicator of relative intravascular volume, and provide empiric evidence that “appropriate” volume removal can improve CO in ICU patients.

Reference PMID: 1) 28261499, 2) 8420299, 3) 12059009, 4) 27539225

Fig 1a: 3D mesh plot of relationships among change in CO with IHD/UF, intravascular volume assessed by IVC CI before IHD, and volume change during IHD. (O) - individual encounters. Letters indicate different response patterns. Fig 1b: Frank Starling curve with response patterns.