Accelerated Venovenous Hemofiltration: Early Technical and Clinical Experience

Background

Renal replacement therapies other than intermittent hemodialysis are often required in hemodynamically unstable patients. Continuous renal replacement therapies use a slow blood flow rate, necessitating anticoagulation and prolonged treatment times that may create difficulties with staffing and limit patient diagnostic and therapeutic procedures. We developed an alternative strategy based on a higher blood flow rate that allows increased rates of hemofiltration, no anticoagulation, and a shorter (“accelerated”) treatment period. We report our technical and clinical experience with accelerated venovenous hemofiltration (AVVH).

Study Design

Case series.

Setting & Participants

Hemodynamically unstable patients requiring renal replacement therapy in the medical or surgical intensive care unit of an academic medial center.

Outcomes & Measurements

Achieved dose, blood flow rate, mean arterial pressure, serum chemistry test results, patient weight, filter clotting, and patient survival.

Results

100 patients received 457 AVVH treatments (average, 4.1 treatments/patient during 5.6 days). Mean Acute Physiology, Age, and Chronic Health Evaluation II score was 24 ± 7.1. Treatment consisted of 36 L of predilution hemofiltration during 9 hours. Mean blood flow was 362 mL/min, and net fluid removal was 2.5 L/treatment. Anticoagulation was not used and filter clotting was seen in only 3.3% of treatments. 86% of patients received the prescribed dose. Pre- and post-AVVH chemistry test results showed a significant decrease in blood urea nitrogen (from 69.6 ± 24.8 to 50.7 ± 22.0 mg/dL) and serum creatinine levels (from 4.3 ± 2.0 to 2.9 ± 1.3 mg/dL). Weight was decreased significantly (from 98.8 ± 26.4 to 93.4 ± 23.1 kg). Pre- and post-AVVH mean arterial pressure comparison showed an increase from 72.8 ± 13.6 to 74.4 ± 15.2 mm Hg. Patient survival rate was 53%.

Limitations

Retrospective analysis, absence of a comparison group.

Conclusion

AVVH is an alternate renal replacement therapy for patients in the intensive care unit and appears to provide adequate volume and solute control without the need for anticoagulation. The shorter treatment period offers flexibility for staffing and other patient diagnostic and therapeutic procedures.

Index Words: Continuous renal replacement therapy, hemodialysis, acute kidney injury