Abstract: SA-PO093

Inferior Vena Cava Diameter Correlates with Ultrafiltrate Removal in Septic Patients with AKI

Session Information

Category: Acute Kidney Injury

  • 003 AKI: Clinical and Translational

Authors

  • Chae, Jung Hee, Augusta University, Augusta, Georgia, United States
  • Waller, Jennifer L., Augusta University, Augusta, Georgia, United States
  • Mohammed, Azeem, Augusta University, Augusta, Georgia, United States
  • White, John Jason, Augusta University, Augusta, Georgia, United States
  • Diamond, Matthew J., Augusta University, Augusta, Georgia, United States
  • Saleem, Muhammad Omar, Augusta University, Augusta, Georgia, United States
  • Nahman, N. Stanley, Augusta University, Augusta, Georgia, United States
Background

The physical examination in septic patients with acute kidney injury (AKI) may over or under estimate effective circulating blood volume. As a result, target ultrafiltration goals (UF) are frequently empiric, often defined in retrospect by hypotension or cardiac instability. We previously showed pre-dialysis inferior vena cava diameter (IVCD) correlated with volume removal in volume-expanded hemodialysis (HD) patients (Mohammed JASN 27:573A). In the present study, we theorized that pre-dialysis IVCD would better estimate and correlate with safe UF removal from septic AKI patients.

Methods

Septic AKI patients were studied before and during the first session of dialysis. Prior to dialysis, systolic blood pressure (SBP), the presence of rales or edema was recorded, and a UF goal was empirically assigned. Two trained operators (JC and AM) assessed IVCD using a GE Sonosite machine prior to the institution of dialysis. Linear regression (LR) was used to examine the association between pre-IVCD and volume removal.

Results

20 septic AKI consented patients (see table) were studied: 60% black, 55% male, 70% hypervolemic (based on the presence of edema or rales), 40% on vasopressors, 55% intubated. Dialysis modalities included HD (n=16) and CRRT (n=4). Pre-dialysis parameters (mean±SD) included: age 59.7±12 yrs, SBP 128.3±22.2 mmHg, IVCD 2.65±0.7 cm. The average volume removed with dialysis was 2.50±1.9L. In the final multiple LR model, only IVCD predicted UF removal controlling for age, edema, volume status, intubation and pre-SBP, where for every one cm increase in pre-IVCD, 2.14 kg of volume was removed (R2 = 0.5182, p < 0.0003). Neither edema nor rales was statistically predictive.

Conclusion

In septic AKI patients, the physical examination is not predictive of UF removal with dialysis, but the pre-dialysis IVCD correlates strongly with the ability to remove excess fluid. Measuring IVCD may improve UF removal estimates in septic patients with AKI, and reduce hypotensive and cardiac events associated with dialysis.

Dialysis modalityAge (yrs)Black race (%)SBP (mmHg)IVCD (cm)Volume removed (L)
HD61.7±9.862.5129.3±23.42.71±0.682.72±1.78
CRRT52±16.550124.2±11.12.46±0.71.63±1.71
Total59.7±1260128.3±22.22.65±0.72.50±1.9